diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 03:55:54 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 03:55:54 +0300 |
| commit | ff6135959a9150ad45cb92ca38da270903a74343 (patch) | |
| tree | 31d7f607078641a425851fc58bed311e3c84f175 /Documentation | |
| parent | f9b4240b074730f41c1ef8e0d695d10fb5bb1e27 (diff) | |
| parent | 47e44ed01434e51e2e42b188482d837c01e5d16e (diff) | |
| download | linux-ff6135959a9150ad45cb92ca38da270903a74343.tar.xz | |
Merge tag 'docs-5.11' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A much quieter cycle for documentation (happily), with, one hopes, the
bulk of the churn behind us. Significant stuff in this pull includes:
- A set of new Chinese translations
- Italian translation updates
- A mechanism from Mauro to automatically format
Documentation/features for the built docs
- Automatic cross references without explicit :ref: markup
- A new reset-controller document
- An extensive new document on reporting problems from Thorsten
That last patch also adds the CC-BY-4.0 license to LICENSES/dual;
there was some discussion on this, but we seem to have consensus and
an ack from Greg for that addition"
* tag 'docs-5.11' of git://git.lwn.net/linux: (50 commits)
docs: fix broken cross reference in translations/zh_CN
docs: Note that sphinx 1.7 will be required soon
docs: update requirements to install six module
docs: reporting-issues: move 'outdated, need help' note to proper place
docs: Update documentation to reflect what TAINT_CPU_OUT_OF_SPEC means
docs: add a reset controller chapter to the driver API docs
docs: make reporting-bugs.rst obsolete
docs: Add a new text describing how to report bugs
LICENSES: Add the CC-BY-4.0 license
Documentation: fix multiple typos found in the admin-guide subdirectory
Documentation: fix typos found in admin-guide subdirectory
kernel-doc: Fix example in Nested structs/unions
docs: clean up sysctl/kernel: titles, version
docs: trace: fix event state structure name
docs: nios2: add missing ReST file
scripts: get_feat.pl: reduce table width for all features output
scripts: get_feat.pl: change the group by order
scripts: get_feat.pl: make complete table more coincise
scripts: kernel-doc: fix parsing function-like typedefs
Documentation: fix typos found in process, dev-tools, and doc-guide subdirectories
...
Diffstat (limited to 'Documentation')
130 files changed, 3184 insertions, 441 deletions
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-ecm b/Documentation/ABI/testing/configfs-usb-gadget-ecm index 272bc1e4ce2e..732101ca9d0b 100644 --- a/Documentation/ABI/testing/configfs-usb-gadget-ecm +++ b/Documentation/ABI/testing/configfs-usb-gadget-ecm @@ -7,7 +7,7 @@ Description: ifname - network device interface name associated with this function instance - qmult + qmult - queue length multiplier for high and super speed host_addr diff --git a/Documentation/ABI/testing/procfs-attr-current b/Documentation/ABI/testing/procfs-attr-current new file mode 100644 index 000000000000..198b9fe1c8e8 --- /dev/null +++ b/Documentation/ABI/testing/procfs-attr-current @@ -0,0 +1,20 @@ +What: /proc/*/attr/current +Contact: linux-security-module@vger.kernel.org, + selinux@vger.kernel.org, + apparmor@lists.ubuntu.com +Description: The current security information used by a Linux + security module (LSM) that is active on the system. + The details of permissions required to read from + this interface and hence obtain the security state + of the task identified is LSM dependent. + A process cannot write to this interface unless it + refers to itself. + The other details of permissions required to write to + this interface and hence change the security state of + the task identified are LSM dependent. + The format of the data used by this interface is LSM + dependent. + SELinux, Smack and AppArmor provide this interface. +Users: SELinux user-space + Smack user-space + AppArmor user-space diff --git a/Documentation/ABI/testing/procfs-attr-exec b/Documentation/ABI/testing/procfs-attr-exec new file mode 100644 index 000000000000..34593866a7ab --- /dev/null +++ b/Documentation/ABI/testing/procfs-attr-exec @@ -0,0 +1,20 @@ +What: /proc/*/attr/exec +Contact: linux-security-module@vger.kernel.org, + selinux@vger.kernel.org, + apparmor@lists.ubuntu.com +Description: The security information to be used on the process + by a Linux security module (LSM) active on the system + after a subsequent exec() call. + The details of permissions required to read from + this interface and hence obtain the security state + of the task identified is LSM dependent. + A process cannot write to this interface unless it + refers to itself. + The other details of permissions required to write to + this interface and hence change the security state of + the task identified are LSM dependent. + The format of the data used by this interface is LSM + dependent. + SELinux and AppArmor provide this interface. +Users: SELinux user-space + AppArmor user-space diff --git a/Documentation/ABI/testing/procfs-attr-prev b/Documentation/ABI/testing/procfs-attr-prev new file mode 100644 index 000000000000..f990b3595839 --- /dev/null +++ b/Documentation/ABI/testing/procfs-attr-prev @@ -0,0 +1,19 @@ +What: /proc/*/attr/prev +Contact: linux-security-module@vger.kernel.org, + selinux@vger.kernel.org, + apparmor@lists.ubuntu.com +Description: The security information used on the process by + a Linux security module (LSM) active on the system + prior to the most recent exec() call. + The details of permissions required to read from + this interface is LSM dependent. + A process cannot write to this interface unless it + refers to itself. + The other details of permissions required to write to + this interface are LSM dependent. + The format of the data used by this interface is LSM + dependent. + SELinux and AppArmor provide this interface. +Users: SELinux user-space + AppArmor user-space + diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory index 2da2b1fba2c1..246a45b96d22 100644 --- a/Documentation/ABI/testing/sysfs-devices-memory +++ b/Documentation/ABI/testing/sysfs-devices-memory @@ -19,7 +19,7 @@ Description: identify removable sections of the memory before attempting potentially expensive hot-remove memory operation Users: hotplug memory remove tools - http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils + http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils What: /sys/devices/system/memory/memoryX/phys_device Date: September 2008 diff --git a/Documentation/ABI/testing/sysfs-fs-ext4 b/Documentation/ABI/testing/sysfs-fs-ext4 index 99e3d92f8299..2edd0a6672d3 100644 --- a/Documentation/ABI/testing/sysfs-fs-ext4 +++ b/Documentation/ABI/testing/sysfs-fs-ext4 @@ -33,7 +33,7 @@ What: /sys/fs/ext4/<disk>/mb_order2_req Date: March 2008 Contact: "Theodore Ts'o" <tytso@mit.edu> Description: - Tuning parameter which controls the minimum size for + Tuning parameter which controls the minimum size for requests (as a power of 2) where the buddy cache is used diff --git a/Documentation/ABI/testing/sysfs-module b/Documentation/ABI/testing/sysfs-module index 353c0db5bc1f..a485434d2a0f 100644 --- a/Documentation/ABI/testing/sysfs-module +++ b/Documentation/ABI/testing/sysfs-module @@ -25,7 +25,7 @@ Description: Maximum time allowed for periodic transfers per microframe (μs) However there are cases, when 80% max isochronous bandwidth is too limiting. For example two video streams could require 110 microseconds of isochronous bandwidth per microframe to work - together. + together. Through this setting it is possible to raise the limit so that the host controller would allow allocating more than 100 diff --git a/Documentation/ABI/testing/sysfs-platform-renesas_usb3 b/Documentation/ABI/testing/sysfs-platform-renesas_usb3 index 8af5b9c3fabb..b08379e7fe37 100644 --- a/Documentation/ABI/testing/sysfs-platform-renesas_usb3 +++ b/Documentation/ABI/testing/sysfs-platform-renesas_usb3 @@ -12,6 +12,6 @@ Description: - "peripheral" - switching mode from host to peripheral. Read the file, then it shows the following strings: - + - "host" - The mode is host now. - "peripheral" - The mode is peripheral now. diff --git a/Documentation/admin-guide/README.rst b/Documentation/admin-guide/README.rst index 95a28f47ac30..261b7b4cca1f 100644 --- a/Documentation/admin-guide/README.rst +++ b/Documentation/admin-guide/README.rst @@ -398,8 +398,8 @@ If something goes wrong If you for some reason cannot do the above (you have a pre-compiled kernel image or similar), telling me as much about your setup as - possible will help. Please read the :ref:`admin-guide/reporting-bugs.rst <reportingbugs>` - document for details. + possible will help. Please read + 'Documentation/admin-guide/reporting-issues.rst' for details. - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you cannot change values or set break points.) To do this, first compile the diff --git a/Documentation/admin-guide/acpi/cppc_sysfs.rst b/Documentation/admin-guide/acpi/cppc_sysfs.rst index a4b99afbe331..fccf22114e85 100644 --- a/Documentation/admin-guide/acpi/cppc_sysfs.rst +++ b/Documentation/admin-guide/acpi/cppc_sysfs.rst @@ -8,7 +8,7 @@ CPPC ==== CPPC defined in the ACPI spec describes a mechanism for the OS to manage the -performance of a logical processor on a contigious and abstract performance +performance of a logical processor on a contiguous and abstract performance scale. CPPC exposes a set of registers to describe abstract performance scale, to request performance levels and to measure per-cpu delivered performance. @@ -45,7 +45,7 @@ for each cpu X:: * lowest_freq : CPU frequency corresponding to lowest_perf (in MHz). * nominal_freq : CPU frequency corresponding to nominal_perf (in MHz). The above frequencies should only be used to report processor performance in - freqency instead of abstract scale. These values should not be used for any + frequency instead of abstract scale. These values should not be used for any functional decisions. * feedback_ctrs : Includes both Reference and delivered performance counter. diff --git a/Documentation/admin-guide/binderfs.rst b/Documentation/admin-guide/binderfs.rst index 8243af9b3510..199d84314a14 100644 --- a/Documentation/admin-guide/binderfs.rst +++ b/Documentation/admin-guide/binderfs.rst @@ -70,5 +70,5 @@ Deleting binder Devices Binderfs binder devices can be deleted via `unlink() <unlink_>`_. This means that the `rm() <rm_>`_ tool can be used to delete them. Note that the ``binder-control`` device cannot be deleted since this would make the binderfs -instance unuseable. The ``binder-control`` device will be deleted when the +instance unusable. The ``binder-control`` device will be deleted when the binderfs instance is unmounted and all references to it have been dropped. diff --git a/Documentation/admin-guide/blockdev/paride.rst b/Documentation/admin-guide/blockdev/paride.rst index 87b4278bf314..e1ce90af602a 100644 --- a/Documentation/admin-guide/blockdev/paride.rst +++ b/Documentation/admin-guide/blockdev/paride.rst @@ -220,7 +220,7 @@ example:: Finally, you can load high-level drivers for each kind of device that you have connected. By default, each driver will autoprobe for a single device, but you can support up to four similar devices by giving their -individual co-ordinates when you load the driver. +individual coordinates when you load the driver. For example, if you had two no-name CD-ROM drives both using the KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index a6fd1f9b5faf..9093228cf18b 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -360,7 +360,7 @@ like below:: /sys/block/zram0/writeback_limit. $ echo 1 > /sys/block/zram0/writeback_limit_enable -If admins want to allow further write again once the bugdet is exhausted, +If admins want to allow further write again once the budget is exhausted, he could do it like below:: $ echo $((400<<MB_SHIFT>>4K_SHIFT)) > \ diff --git a/Documentation/admin-guide/bug-bisect.rst b/Documentation/admin-guide/bug-bisect.rst index 59567da344e8..325c5d0ed34a 100644 --- a/Documentation/admin-guide/bug-bisect.rst +++ b/Documentation/admin-guide/bug-bisect.rst @@ -15,7 +15,7 @@ give up. Report as much as you have found to the relevant maintainer. See MAINTAINERS for who that is for the subsystem you have worked on. Before you submit a bug report read -:ref:`Documentation/admin-guide/reporting-bugs.rst <reportingbugs>`. +'Documentation/admin-guide/reporting-issues.rst'. Devices not appearing ===================== diff --git a/Documentation/admin-guide/bug-hunting.rst b/Documentation/admin-guide/bug-hunting.rst index f7c80f4649fc..95299b08c405 100644 --- a/Documentation/admin-guide/bug-hunting.rst +++ b/Documentation/admin-guide/bug-hunting.rst @@ -263,7 +263,7 @@ Please notice that it will point to: - The last developers that touched the source code (if this is done inside a git tree). On the above example, Tejun and Bhaktipriya (in this - specific case, none really envolved on the development of this file); + specific case, none really involved on the development of this file); - The driver maintainer (Hans Verkuil); - The subsystem maintainer (Mauro Carvalho Chehab); - The driver and/or subsystem mailing list (linux-media@vger.kernel.org); diff --git a/Documentation/admin-guide/cifs/introduction.rst b/Documentation/admin-guide/cifs/introduction.rst index 0b98f672d36f..cc2851d93d17 100644 --- a/Documentation/admin-guide/cifs/introduction.rst +++ b/Documentation/admin-guide/cifs/introduction.rst @@ -9,7 +9,7 @@ Introduction PC operating systems. New and improved versions of CIFS are now called SMB2 and SMB3. Use of SMB3 (and later, including SMB3.1.1) is strongly preferred over using older dialects like CIFS due to - security reaasons. All modern dialects, including the most recent, + security reasons. All modern dialects, including the most recent, SMB3.1.1 are supported by the CIFS VFS module. The SMB3 protocol is implemented and supported by all major file servers such as all modern versions of Windows (including Windows 2016 diff --git a/Documentation/admin-guide/cifs/usage.rst b/Documentation/admin-guide/cifs/usage.rst index 7b32d5063803..b6d9f02bc12b 100644 --- a/Documentation/admin-guide/cifs/usage.rst +++ b/Documentation/admin-guide/cifs/usage.rst @@ -115,7 +115,7 @@ later source tree in docs/manpages/mount.cifs.8 Allowing User Unmounts ====================== -To permit users to ummount directories that they have user mounted (see above), +To permit users to unmount directories that they have user mounted (see above), the utility umount.cifs may be used. It may be invoked directly, or if umount.cifs is placed in /sbin, umount can invoke the cifs umount helper (at least for most versions of the umount utility) for umount of cifs @@ -197,7 +197,7 @@ that is ignored by local server applications and non-cifs clients and that will not be traversed by the Samba server). This is opaque to the Linux client application using the cifs vfs. Absolute symlinks will work to Samba 3.0.5 or later, but only for remote clients using the CIFS Unix extensions, and will -be invisbile to Windows clients and typically will not affect local +be invisible to Windows clients and typically will not affect local applications running on the same server as Samba. Use instructions @@ -267,7 +267,7 @@ would be forbidden for Windows/CIFS semantics) as long as the server is configured for Unix Extensions (and the client has not disabled /proc/fs/cifs/LinuxExtensionsEnabled). In addition the mount option ``mapposix`` can be used on CIFS (vers=1.0) to force the mapping of -illegal Windows/NTFS/SMB characters to a remap range (this mount parm +illegal Windows/NTFS/SMB characters to a remap range (this mount parameter is the default for SMB3). This remap (``mapposix``) range is also compatible with Mac (and "Services for Mac" on some older Windows). diff --git a/Documentation/admin-guide/device-mapper/dm-crypt.rst b/Documentation/admin-guide/device-mapper/dm-crypt.rst index bc28a9527ee5..1a6753b76dbb 100644 --- a/Documentation/admin-guide/device-mapper/dm-crypt.rst +++ b/Documentation/admin-guide/device-mapper/dm-crypt.rst @@ -46,7 +46,7 @@ Parameters:: capi:authenc(hmac(sha256),xts(aes))-random capi:rfc7539(chacha20,poly1305)-random - The /proc/crypto contains a list of curently loaded crypto modes. + The /proc/crypto contains a list of currently loaded crypto modes. <key> Key used for encryption. It is encoded either as a hexadecimal number @@ -92,7 +92,7 @@ Parameters:: <#opt_params> Number of optional parameters. If there are no optional parameters, - the optional paramaters section can be skipped or #opt_params can be zero. + the optional parameters section can be skipped or #opt_params can be zero. Otherwise #opt_params is the number of following arguments. Example of optional parameters section: diff --git a/Documentation/admin-guide/device-mapper/dm-integrity.rst b/Documentation/admin-guide/device-mapper/dm-integrity.rst index 3ab4f7756a6e..4e6f504474ac 100644 --- a/Documentation/admin-guide/device-mapper/dm-integrity.rst +++ b/Documentation/admin-guide/device-mapper/dm-integrity.rst @@ -117,7 +117,7 @@ journal_watermark:number commit_time:number Commit time in milliseconds. When this time passes, the journal is - written. The journal is also written immediatelly if the FLUSH + written. The journal is also written immediately if the FLUSH request is received. internal_hash:algorithm(:key) (the key is optional) @@ -147,7 +147,7 @@ journal_crypt:algorithm(:key) (the key is optional) "salsa20" or "ctr(aes)"). The journal contains history of last writes to the block device, - an attacker reading the journal could see the last sector nubmers + an attacker reading the journal could see the last sector numbers that were written. From the sector numbers, the attacker can infer the size of files that were written. To protect against this situation, you can encrypt the journal. diff --git a/Documentation/admin-guide/device-mapper/dm-raid.rst b/Documentation/admin-guide/device-mapper/dm-raid.rst index 7ef9fe63b3d4..bb17e26e3c1b 100644 --- a/Documentation/admin-guide/device-mapper/dm-raid.rst +++ b/Documentation/admin-guide/device-mapper/dm-raid.rst @@ -418,6 +418,6 @@ Version History specific devices are requested via rebuild. Fix RAID leg rebuild errors. 1.15.0 Fix size extensions not being synchronized in case of new MD bitmap - pages allocated; also fix those not occuring after previous reductions + pages allocated; also fix those not occurring after previous reductions 1.15.1 Fix argument count and arguments for rebuild/write_mostly/journal_(dev|mode) on the status line. diff --git a/Documentation/admin-guide/device-mapper/dm-zoned.rst b/Documentation/admin-guide/device-mapper/dm-zoned.rst index e635041351bc..0fac051caeac 100644 --- a/Documentation/admin-guide/device-mapper/dm-zoned.rst +++ b/Documentation/admin-guide/device-mapper/dm-zoned.rst @@ -24,7 +24,7 @@ The dm-zoned implementation is simple and minimizes system overhead (CPU and memory usage as well as storage capacity loss). For a 10TB host-managed disk with 256 MB zones, dm-zoned memory usage per disk instance is at most 4.5 MB and as little as 5 zones will be used -internally for storing metadata and performaing reclaim operations. +internally for storing metadata and performing reclaim operations. dm-zoned target devices are formatted and checked using the dmzadm utility available at: @@ -102,7 +102,7 @@ the buffer zone assigned. If the accessed chunk has no mapping, or the accessed blocks are invalid, the read buffer is zeroed and the read operation terminated. -After some time, the limited number of convnetional zones available may +After some time, the limited number of conventional zones available may be exhausted (all used to map chunks or buffer sequential zones) and unaligned writes to unbuffered chunks become impossible. To avoid this situation, a reclaim process regularly scans used conventional zones and @@ -158,7 +158,7 @@ Ex:: dmzadm --format /dev/sdxx /dev/sdyy -Fomatted device(s) can be started with the dmzadm utility, too.: +Formatted device(s) can be started with the dmzadm utility, too.: Ex:: diff --git a/Documentation/admin-guide/device-mapper/verity.rst b/Documentation/admin-guide/device-mapper/verity.rst index 66f71f0dab1b..8c50e5c96ee1 100644 --- a/Documentation/admin-guide/device-mapper/verity.rst +++ b/Documentation/admin-guide/device-mapper/verity.rst @@ -69,7 +69,7 @@ Construction Parameters <#opt_params> Number of optional parameters. If there are no optional parameters, - the optional paramaters section can be skipped or #opt_params can be zero. + the optional parameters section can be skipped or #opt_params can be zero. Otherwise #opt_params is the number of following arguments. Example of optional parameters section: diff --git a/Documentation/admin-guide/device-mapper/writecache.rst b/Documentation/admin-guide/device-mapper/writecache.rst index d3d7690f5e8d..dce0184e07ca 100644 --- a/Documentation/admin-guide/device-mapper/writecache.rst +++ b/Documentation/admin-guide/device-mapper/writecache.rst @@ -37,10 +37,10 @@ Constructor parameters: autocommit_blocks n (default: 64 for pmem, 65536 for ssd) when the application writes this amount of blocks without issuing the FLUSH request, the blocks are automatically - commited + committed autocommit_time ms (default: 1000) autocommit time in milliseconds. The data is automatically - commited if this time passes and no FLUSH request is + committed if this time passes and no FLUSH request is received fua (by default on) applicable only to persistent memory - use the FUA flag diff --git a/Documentation/admin-guide/features.rst b/Documentation/admin-guide/features.rst new file mode 100644 index 000000000000..8c167082a84f --- /dev/null +++ b/Documentation/admin-guide/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features diff --git a/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst b/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst index 68d96f0e9c95..76673affd917 100644 --- a/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst +++ b/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst @@ -60,7 +60,7 @@ Hyper-Thread attacks are possible. The victim of a malicious actor does not need to make use of TSX. Only the attacker needs to begin a TSX transaction and raise an asynchronous abort -which in turn potenitally leaks data stored in the buffers. +which in turn potentially leaks data stored in the buffers. More detailed technical information is available in the TAA specific x86 architecture section: :ref:`Documentation/x86/tsx_async_abort.rst <tsx_async_abort>`. diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst index 4e0c4ae44acd..621d1c583738 100644 --- a/Documentation/admin-guide/index.rst +++ b/Documentation/admin-guide/index.rst @@ -19,6 +19,7 @@ etc. sysctl/index abi + features This section describes CPU vulnerabilities and their mitigations. @@ -33,7 +34,8 @@ problems and bugs in particular. .. toctree:: :maxdepth: 1 - reporting-bugs + reporting-issues + Reporting bugs (obsolete) <reporting-bugs> security-bugs bug-hunting bug-bisect diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst index 6d421694d98e..06fb1b4aa849 100644 --- a/Documentation/admin-guide/kernel-parameters.rst +++ b/Documentation/admin-guide/kernel-parameters.rst @@ -172,6 +172,7 @@ parameter is applicable:: X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64) X86_UV SGI UV support is enabled. XEN Xen support is enabled + XTENSA xtensa architecture is enabled. In addition, the following text indicates that the option:: diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a7d60d847584..23f209c8c19a 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2709,7 +2709,7 @@ option description. memmap=nn[KMG]@ss[KMG] - [KNL] Force usage of a specific region of memory. + [KNL, X86, MIPS, XTENSA] Force usage of a specific region of memory. Region of memory to be used is from ss to ss+nn. If @ss[KMG] is omitted, it is equivalent to mem=nn[KMG], which limits max address to nn[KMG]. diff --git a/Documentation/admin-guide/md.rst b/Documentation/admin-guide/md.rst index cc8781b96b4d..d8fc9a59c086 100644 --- a/Documentation/admin-guide/md.rst +++ b/Documentation/admin-guide/md.rst @@ -221,7 +221,7 @@ All md devices contain: layout The ``layout`` for the array for the particular level. This is - simply a number that is interpretted differently by different + simply a number that is interpreted differently by different levels. It can be written while assembling an array. array_size diff --git a/Documentation/admin-guide/media/bttv.rst b/Documentation/admin-guide/media/bttv.rst index 49382377b1dc..0ef1f203104d 100644 --- a/Documentation/admin-guide/media/bttv.rst +++ b/Documentation/admin-guide/media/bttv.rst @@ -77,7 +77,7 @@ the Subsystem ID in the second line, looks like this: only bt878-based cards can have a subsystem ID (which does not mean that every card really has one). bt848 cards can't have a Subsystem ID and therefore can't be autodetected. There is a list with the ID's -at :doc:`bttv-cardlist` (in case you are intrested or want to mail +at :doc:`bttv-cardlist` (in case you are interested or want to mail patches with updates). diff --git a/Documentation/admin-guide/media/dvb_references.rst b/Documentation/admin-guide/media/dvb_references.rst index 48445ac76275..4f0fd4259cfa 100644 --- a/Documentation/admin-guide/media/dvb_references.rst +++ b/Documentation/admin-guide/media/dvb_references.rst @@ -10,7 +10,7 @@ The DVB mailing list linux-dvb is hosted at vger. Please see http://vger.kernel.org/vger-lists.html#linux-media for details. There are also some other old lists hosted at: -https://linuxtv.org/lists.php. If you're insterested on that for historic +https://linuxtv.org/lists.php. If you're interested on that for historic reasons, please check the archive at https://linuxtv.org/pipermail/linux-dvb/. The media subsystem Wiki is hosted at https://linuxtv.org/wiki/. diff --git a/Documentation/admin-guide/media/frontend-cardlist.rst b/Documentation/admin-guide/media/frontend-cardlist.rst index 73a248c1b064..ba5b7c69a978 100644 --- a/Documentation/admin-guide/media/frontend-cardlist.rst +++ b/Documentation/admin-guide/media/frontend-cardlist.rst @@ -68,7 +68,7 @@ cx24116 Conexant CX24116 based cx24117 Conexant CX24117 based cx24120 Conexant CX24120 based cx24123 Conexant CX24123 based -ds3000 Montage Tehnology DS3000 based +ds3000 Montage Technology DS3000 based mb86a16 Fujitsu MB86A16 based mt312 Zarlink VP310/MT312/ZL10313 based s5h1420 Samsung S5H1420 based @@ -83,7 +83,7 @@ tda10086 Philips TDA10086 based tda8083 Philips TDA8083 based tda8261 Philips TDA8261 based tda826x Philips TDA826X silicon tuner -ts2020 Montage Tehnology TS2020 based tuners +ts2020 Montage Technology TS2020 based tuners tua6100 Infineon TUA6100 PLL cx24113 Conexant CX24113/CX24128 tuner for DVB-S/DSS itd1000 Integrant ITD1000 Zero IF tuner for DVB-S/DSS diff --git a/Documentation/admin-guide/media/gspca-cardlist.rst b/Documentation/admin-guide/media/gspca-cardlist.rst index adda933616f1..e3404d1589da 100644 --- a/Documentation/admin-guide/media/gspca-cardlist.rst +++ b/Documentation/admin-guide/media/gspca-cardlist.rst @@ -305,7 +305,7 @@ pac7302 093a:2625 Genius iSlim 310 pac7302 093a:2626 Labtec 2200 pac7302 093a:2627 Genius FaceCam 300 pac7302 093a:2628 Genius iLook 300 -pac7302 093a:2629 Genious iSlim 300 +pac7302 093a:2629 Genius iSlim 300 pac7302 093a:262a Webcam 300k pac7302 093a:262c Philips SPC 230 NC jl2005bcd 0979:0227 Various brands, 19 known cameras supported diff --git a/Documentation/admin-guide/media/ipu3.rst b/Documentation/admin-guide/media/ipu3.rst index 07d139bf8459..f59697c7b374 100644 --- a/Documentation/admin-guide/media/ipu3.rst +++ b/Documentation/admin-guide/media/ipu3.rst @@ -86,7 +86,7 @@ raw Bayer format that is specific to IPU3. Let us take the example of ov5670 sensor connected to CSI2 port 0, for a 2592x1944 image capture. -Using the media contorller APIs, the ov5670 sensor is configured to send +Using the media controller APIs, the ov5670 sensor is configured to send frames in packed raw Bayer format to IPU3 CSI2 receiver. .. code-block:: none @@ -313,8 +313,8 @@ configuration steps of 0.03125 (1/32). **Geometric Distortion Correction** -Geometric Distortion Correction is used to performe correction of distortions -and image filtering. It needs some extra filter and envelop padding pixels to +Geometric Distortion Correction is used to perform correction of distortions +and image filtering. It needs some extra filter and envelope padding pixels to work, so the input resolution of GDC should be larger than the output resolution. diff --git a/Documentation/admin-guide/media/remote-controller.rst b/Documentation/admin-guide/media/remote-controller.rst index fa05410c3cd5..188944b00f4f 100644 --- a/Documentation/admin-guide/media/remote-controller.rst +++ b/Documentation/admin-guide/media/remote-controller.rst @@ -68,7 +68,7 @@ Using without lircd Xorg recognizes several IR keycodes that have its numerical value lower than 247. With the advent of Wayland, the input driver got updated too, -and should now accept all keycodes. Yet, you may want to just reasign +and should now accept all keycodes. Yet, you may want to just reassign the keycodes to something that your favorite media application likes. This can be done by setting diff --git a/Documentation/admin-guide/mm/index.rst b/Documentation/admin-guide/mm/index.rst index cd727cfc1b04..4b14d8b50e9e 100644 --- a/Documentation/admin-guide/mm/index.rst +++ b/Documentation/admin-guide/mm/index.rst @@ -3,9 +3,9 @@ Memory Management ================= Linux memory management subsystem is responsible, as the name implies, -for managing the memory in the system. This includes implemnetation of +for managing the memory in the system. This includes implementation of virtual memory and demand paging, memory allocation both for kernel -internal structures and user space programms, mapping of files into +internal structures and user space programs, mapping of files into processes address space and many other cool things. Linux memory management is a complex system with many configurable diff --git a/Documentation/admin-guide/mm/numaperf.rst b/Documentation/admin-guide/mm/numaperf.rst index 86f2a3c4b638..c2f826409bf0 100644 --- a/Documentation/admin-guide/mm/numaperf.rst +++ b/Documentation/admin-guide/mm/numaperf.rst @@ -74,7 +74,7 @@ memory node's access class 0 initiators as follows:: /sys/devices/system/node/nodeY/access0/initiators/ These attributes apply only when accessed from nodes that have the -are linked under the this access's inititiators. +are linked under the this access's initiators. The performance characteristics the kernel provides for the local initiators are exported are as follows:: diff --git a/Documentation/admin-guide/mm/userfaultfd.rst b/Documentation/admin-guide/mm/userfaultfd.rst index 1dc2d5f823b4..65eefa66c0ba 100644 --- a/Documentation/admin-guide/mm/userfaultfd.rst +++ b/Documentation/admin-guide/mm/userfaultfd.rst @@ -114,7 +114,7 @@ Notes: you must provide some kind of page in your thread after reading from the uffd. You must provide either ``UFFDIO_COPY`` or ``UFFDIO_ZEROPAGE``. The normal behavior of the OS automatically providing a zero page on - an annonymous mmaping is not in place. + an anonymous mmaping is not in place. - None of the page-delivering ioctls default to the range that you registered with. You must fill in all fields for the appropriate diff --git a/Documentation/admin-guide/module-signing.rst b/Documentation/admin-guide/module-signing.rst index f8b584179cff..7d7c7c8a545c 100644 --- a/Documentation/admin-guide/module-signing.rst +++ b/Documentation/admin-guide/module-signing.rst @@ -106,7 +106,7 @@ This has a number of options available: certificate and a private key. If the PEM file containing the private key is encrypted, or if the - PKCS#11 token requries a PIN, this can be provided at build time by + PKCS#11 token requires a PIN, this can be provided at build time by means of the ``KBUILD_SIGN_PIN`` variable. diff --git a/Documentation/admin-guide/perf/imx-ddr.rst b/Documentation/admin-guide/perf/imx-ddr.rst index f05f56c73b7d..90926d0fb8ec 100644 --- a/Documentation/admin-guide/perf/imx-ddr.rst +++ b/Documentation/admin-guide/perf/imx-ddr.rst @@ -4,7 +4,7 @@ Freescale i.MX8 DDR Performance Monitoring Unit (PMU) There are no performance counters inside the DRAM controller, so performance signals are brought out to the edge of the controller where a set of 4 x 32 bit -counters is implemented. This is controlled by the CSV modes programed in counter +counters is implemented. This is controlled by the CSV modes programmed in counter control register which causes a large number of PERF signals to be generated. Selection of the value for each counter is done via the config registers. There diff --git a/Documentation/admin-guide/pm/intel-speed-select.rst b/Documentation/admin-guide/pm/intel-speed-select.rst index 219f1359aac7..0a1fbdb54bfe 100644 --- a/Documentation/admin-guide/pm/intel-speed-select.rst +++ b/Documentation/admin-guide/pm/intel-speed-select.rst @@ -57,7 +57,7 @@ To get help on a command, another level of help is provided. For example for the Summary of platform capability ------------------------------ -To check the current platform and driver capaibilities, execute:: +To check the current platform and driver capabilities, execute:: #intel-speed-select --info @@ -658,7 +658,7 @@ If -a option is not used, then the following steps are required before enabling Intel(R) SST-BF: - Discover Intel(R) SST-BF and note low and high priority base frequency -- Note the high prioity CPU list +- Note the high priority CPU list - Enable CLOS using core-power feature set - Configure CLOS parameters. Use CLOS.min to set to minimum performance - Subscribe desired CPUs to CLOS groups diff --git a/Documentation/admin-guide/pm/intel_pstate.rst b/Documentation/admin-guide/pm/intel_pstate.rst index 5072e7064d13..df29b4f1f219 100644 --- a/Documentation/admin-guide/pm/intel_pstate.rst +++ b/Documentation/admin-guide/pm/intel_pstate.rst @@ -56,7 +56,7 @@ Operation Modes ``intel_pstate`` can operate in two different modes, active or passive. In the active mode, it uses its own internal performance scaling governor algorithm or -allows the hardware to do preformance scaling by itself, while in the passive +allows the hardware to do performance scaling by itself, while in the passive mode it responds to requests made by a generic ``CPUFreq`` governor implementing a certain performance scaling algorithm. Which of them will be in effect depends on what kernel command line options are used and on the capabilities of @@ -380,13 +380,13 @@ argument is passed to the kernel in the command line. ``no_turbo`` If set (equal to 1), the driver is not allowed to set any turbo P-states - (see `Turbo P-states Support`_). If unset (equalt to 0, which is the + (see `Turbo P-states Support`_). If unset (equal to 0, which is the default), turbo P-states can be set by the driver. [Note that ``intel_pstate`` does not support the general ``boost`` attribute (supported by some other scaling drivers) which is replaced by this one.] - This attrubute does not affect the maximum supported frequency value + This attribute does not affect the maximum supported frequency value supplied to the ``CPUFreq`` core and exposed via the policy interface, but it affects the maximum possible value of per-policy P-state limits (see `Interpretation of Policy Attributes`_ below for details). diff --git a/Documentation/admin-guide/ramoops.rst b/Documentation/admin-guide/ramoops.rst index a60a96218ba9..b0a1ae7df13b 100644 --- a/Documentation/admin-guide/ramoops.rst +++ b/Documentation/admin-guide/ramoops.rst @@ -22,7 +22,7 @@ and type of the memory area are set using three variables: * ``mem_address`` for the start * ``mem_size`` for the size. The memory size will be rounded down to a power of two. - * ``mem_type`` to specifiy if the memory type (default is pgprot_writecombine). + * ``mem_type`` to specify if the memory type (default is pgprot_writecombine). Typically the default value of ``mem_type=0`` should be used as that sets the pstore mapping to pgprot_writecombine. Setting ``mem_type=1`` attempts to use diff --git a/Documentation/admin-guide/reporting-bugs.rst b/Documentation/admin-guide/reporting-bugs.rst index 42481ea7b41d..409fa91d7495 100644 --- a/Documentation/admin-guide/reporting-bugs.rst +++ b/Documentation/admin-guide/reporting-bugs.rst @@ -1,5 +1,10 @@ .. _reportingbugs: +.. note:: + + This document is obsolete, and will be replaced by + 'Documentation/admin-guide/reporting-issues.rst' in the near future. + Reporting bugs ++++++++++++++ diff --git a/Documentation/admin-guide/reporting-issues.rst b/Documentation/admin-guide/reporting-issues.rst new file mode 100644 index 000000000000..07879d01fe68 --- /dev/null +++ b/Documentation/admin-guide/reporting-issues.rst @@ -0,0 +1,1631 @@ +.. SPDX-License-Identifier: (GPL-2.0+ OR CC-BY-4.0) +.. + If you want to distribute this text under CC-BY-4.0 only, please use 'The + Linux kernel developers' for author attribution and link this as source: + https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/Documentation/admin-guide/reporting-issues.rst +.. + Note: Only the content of this RST file as found in the Linux kernel sources + is available under CC-BY-4.0, as versions of this text that were processed + (for example by the kernel's build system) might contain content taken from + files which use a more restrictive license. + +.. important:: + + This document is being prepared to replace + 'Documentation/admin-guide/reporting-bugs.rst'. The main work is done and + you are already free to follow its instructions when reporting issues to the + Linux kernel developers. But keep in mind, below text still needs a few + finishing touches and review. It was merged to the Linux kernel sources at + this stage to make this process easier and increase the text's visibility. + + Any improvements for the text or other feedback is thus very much welcome. + Please send it to 'Thorsten Leemhuis <linux@leemhuis.info>' and 'Jonathan + Corbet <corbet@lwn.net>', ideally with 'Linux kernel mailing list (LKML) + <linux-kernel@vger.kernel.org>' and the 'Linux Kernel Documentation List + <linux-doc@vger.kernel.org>' in CC. + + Areas in the text that still need work or discussion contain a hint like this + which point out the remaining issues; all of them start with the word "FIXME" + to make them easy to find. + + +Reporting issues +++++++++++++++++ + + +The short guide (aka TL;DR) +=========================== + +If you're facing multiple issues with the Linux kernel at once, report each +separately to its developers. Try your best guess which kernel part might be +causing the issue. Check the :ref:`MAINTAINERS <maintainers>` file for how its +developers expect to be told about issues. Note, it's rarely +`bugzilla.kernel.org <https://bugzilla.kernel.org/>`_, as in almost all cases +the report needs to be sent by email! + +Check the destination thoroughly for existing reports; also search the LKML +archives and the web. Join existing discussion if you find matches. If you +don't find any, install `the latest Linux mainline kernel +<https://kernel.org/>`_. Make sure it's vanilla, thus is not patched or using +add-on kernel modules. Also ensure the kernel is running in a healthy +environment and is not already tainted before the issue occurs. + +If you can reproduce your issue with the mainline kernel, send a report to the +destination you determined earlier. Make sure it includes all relevant +information, which in case of a regression should mention the change that's +causing it which can often can be found with a bisection. Also ensure the +report reaches all people that need to know about it, for example the security +team, the stable maintainers or the developers of the patch that causes a +regression. Once the report is out, answer any questions that might be raised +and help where you can. That includes keeping the ball rolling: every time a +new rc1 mainline kernel is released, check if the issue is still happening +there and attach a status update to your initial report. + +If you can not reproduce the issue with the mainline kernel, consider sticking +with it; if you'd like to use an older version line and want to see it fixed +there, first make sure it's still supported. Install its latest release as +vanilla kernel. If you cannot reproduce the issue there, try to find the commit +that fixed it in mainline or any discussion preceding it: those will often +mention if backporting is planed or considered too complex. If backporting was +not discussed, ask if it's in the cards. In case you don't find any commits or +a preceding discussion, see the Linux-stable mailing list archives for existing +reports, as it might be a regression specific to the version line. If it is, +report it like you would report a problem in mainline (including the +bisection). + +If you reached this point without a solution, ask for advice one the +subsystem's mailing list. + + +Step-by-step guide how to report issues to the kernel maintainers +================================================================= + +The above TL;DR outlines roughly how to report issues to the Linux kernel +developers. It might be all that's needed for people already familiar with +reporting issues to Free/Libre & Open Source Software (FLOSS) projects. For +everyone else there is this section. It is more detailed and uses a +step-by-step approach. It still tries to be brief for readability and leaves +out a lot of details; those are described below the step-by-step guide in a +reference section, which explains each of the steps in more detail. + +Note: this section covers a few more aspects than the TL;DR and does things in +a slightly different order. That's in your interest, to make sure you notice +early if an issue that looks like a Linux kernel problem is actually caused by +something else. These steps thus help to ensure the time you invest in this +process won't feel wasted in the end: + + * Stop reading this document and report the problem to your vendor instead, + unless you are running the latest mainline kernel already or are willing to + install it. This kernel must not be modified or enhanced in any way, and + thus be considered 'vanilla'. + + * See if the issue you are dealing with qualifies as regression, security + issue, or a really severe problem: those are 'issues of high priority' that + need special handling in some steps that are about to follow. + + * Check if your kernel was 'tainted' when the issue occurred, as the event + that made the kernel set this flag might be causing the issue you face. + + * Locate the driver or kernel subsystem that seems to be causing the issue. + Find out how and where its developers expect reports. Note: most of the + time this won't be bugzilla.kernel.org, as issues typically need to be sent + by mail to a maintainer and a public mailing list. + + * Search the archives of the bug tracker or mailing list in question + thoroughly for reports that might match your issue. Also check if you find + something with your favorite internet search engine or in the Linux Kernel + Mailing List (LKML) archives. If you find anything, join the discussion + instead of sending a new report. + + * Create a fresh backup and put system repair and restore tools at hand. + + * Ensure your system does not enhance its kernels by building additional + kernel modules on-the-fly, which solutions like DKMS might be doing locally + without your knowledge. + + * Make sure it's not the kernel's surroundings that are causing the issue + you face. + + * Write down coarsely how to reproduce the issue. If you deal with multiple + issues at once, create separate notes for each of them and make sure they + work independently on a freshly booted system. That's needed, as each issue + needs to get reported to the kernel developers separately, unless they are + strongly entangled. + +After these preparations you'll now enter the main part: + + * Install the latest Linux mainline kernel: that's where all issues get + fixed first, because it's the version line the kernel developers mainly + care about. Testing and reporting with the latest Linux stable kernel can + be an acceptable alternative in some situations, for example during the + merge window; but during that period you might want to suspend your efforts + till its end anyway. + + * Ensure the kernel you just installed does not 'taint' itself when + running. + + * Reproduce the issue with the kernel you just installed. If it doesn't show + up there, head over to the instructions for issues only happening with + stable and longterm kernels. + + * Optimize your notes: try to find and write the most straightforward way to + reproduce your issue. Make sure the end result has all the important + details, and at the same time is easy to read and understand for others + that hear about it for the first time. And if you learned something in this + process, consider searching again for existing reports about the issue. + + * If the failure includes a stack dump, like an Oops does, consider decoding + it to find the offending line of code. + + * If your problem is a regression, try to narrow down when the issue was + introduced as much as possible. + + * Start to compile the report by writing a detailed description about the + issue. Always mention a few things: the latest kernel version you installed + for reproducing, the Linux Distribution used, and your notes on how to + reproduce the issue. Ideally, make the kernel's build configuration + (.config) and the output from ``dmesg`` available somewhere on the net and + link to it. Include or upload all other information that might be relevant, + like the output/screenshot of an Oops or the output from ``lspci``. Once + you wrote this main part, insert a normal length paragraph on top of it + outlining the issue and the impact quickly. On top of this add one sentence + that briefly describes the problem and gets people to read on. Now give the + thing a descriptive title or subject that yet again is shorter. Then you're + ready to send or file the report like the MAINTAINERS file told you, unless + you are dealing with one of those 'issues of high priority': they need + special care which is explained in 'Special handling for high priority + issues' below. + + * Wait for reactions and keep the thing rolling until you can accept the + outcome in one way or the other. Thus react publicly and in a timely manner + to any inquiries. Test proposed fixes. Do proactive testing: retest with at + least every first release candidate (RC) of a new mainline version and + report your results. Send friendly reminders if things stall. And try to + help yourself, if you don't get any help or if it's unsatisfying. + + +Reporting issues only occurring in older kernel version lines +------------------------------------------------------------- + +This section is for you, if you tried the latest mainline kernel as outlined +above, but failed to reproduce your issue there; at the same time you want to +see the issue fixed in older version lines or a vendor kernel that's regularly +rebased on new stable or longterm releases. If that case follow these steps: + + * Prepare yourself for the possibility that going through the next few steps + might not get the issue solved in older releases: the fix might be too big + or risky to get backported there. + + * Check if the kernel developers still maintain the Linux kernel version + line you care about: go to the front page of kernel.org and make sure it + mentions the latest release of the particular version line without an + '[EOL]' tag. + + * Check the archives of the Linux stable mailing list for existing reports. + + * Install the latest release from the particular version line as a vanilla + kernel. Ensure this kernel is not tainted and still shows the problem, as + the issue might have already been fixed there. + + * Search the Linux kernel version control system for the change that fixed + the issue in mainline, as its commit message might tell you if the fix is + scheduled for backporting already. If you don't find anything that way, + search the appropriate mailing lists for posts that discuss such an issue + or peer-review possible fixes; then check the discussions if the fix was + deemed unsuitable for backporting. If backporting was not considered at + all, join the newest discussion, asking if it's in the cards. + + * Check if you're dealing with a regression that was never present in + mainline by installing the first release of the version line you care + about. If the issue doesn't show up with it, you basically need to report + the issue with this version like you would report a problem with mainline + (see above). This ideally includes a bisection followed by a search for + existing reports on the net; with the help of the subject and the two + relevant commit-ids. If that doesn't turn up anything, write the report; CC + or forward the report to the stable maintainers, the stable mailing list, + and those who authored the change. Include the shortened commit-id if you + found the change that causes it. + + * One of the former steps should lead to a solution. If that doesn't work + out, ask the maintainers for the subsystem that seems to be causing the + issue for advice; CC the mailing list for the particular subsystem as well + as the stable mailing list. + + +Reference section: Reporting issues to the kernel maintainers +============================================================= + +The detailed guides above outline all the major steps in brief fashion, which +should be enough for most people. But sometimes there are situations where even +experienced users might wonder how to actually do one of those steps. That's +what this section is for, as it will provide a lot more details on each of the +above steps. Consider this as reference documentation: it's possible to read it +from top to bottom. But it's mainly meant to skim over and a place to look up +details how to actually perform those steps. + +A few words of general advice before digging into the details: + + * The Linux kernel developers are well aware this process is complicated and + demands more than other FLOSS projects. We'd love to make it simpler. But + that would require work in various places as well as some infrastructure, + which would need constant maintenance; nobody has stepped up to do that + work, so that's just how things are for now. + + * A warranty or support contract with some vendor doesn't entitle you to + request fixes from developers in the upstream Linux kernel community: such + contracts are completely outside the scope of the Linux kernel, its + development community, and this document. That's why you can't demand + anything such a contract guarantees in this context, not even if the + developer handling the issue works for the vendor in question. If you want + to claim your rights, use the vendor's support channel instead. When doing + so, you might want to mention you'd like to see the issue fixed in the + upstream Linux kernel; motivate them by saying it's the only way to ensure + the fix in the end will get incorporated in all Linux distributions. + + * If you never reported an issue to a FLOSS project before you should consider + reading `How to Report Bugs Effectively + <https://www.chiark.greenend.org.uk/~sgtatham/bugs.html>`_, `How To Ask + Questions The Smart Way + <http://www.catb.org/esr/faqs/smart-questions.html>`_, and `How to ask good + questions <https://jvns.ca/blog/good-questions/>`_. + +With that off the table, find below the details on how to properly report +issues to the Linux kernel developers. + + +Make sure you're using the upstream Linux kernel +------------------------------------------------ + + *Stop reading this document and report the problem to your vendor instead, + unless you are running the latest mainline kernel already or are willing to + install it. This kernel must not be modified or enhanced in any way, and + thus be considered 'vanilla'.* + +Like most programmers, Linux kernel developers don't like to spend time dealing +with reports for issues that don't even happen with the source code they +maintain: it's just a waste everybody's time, yours included. That's why you +later will have to test your issue with the latest 'vanilla' kernel: a kernel +that was build using the Linux sources taken straight from `kernel.org +<https://kernel.org/>`_ and not modified or enhanced in any way. + +Almost all kernels used in devices (Computers, Laptops, Smartphones, Routers, +…) and most kernels shipped by Linux distributors are ancient from the point of +kernel development and heavily modified. They thus do not qualify for reporting +an issue to the Linux kernel developers: the issue you face with such a kernel +might be fixed already or caused by the changes or additions, even if they look +small or totally unrelated. That's why issues with such kernels need to be +reported to the vendor that distributed it. Its developers should look into the +report and, in case it turns out to be an upstream issue, fix it directly +upstream or report it there. In practice that sometimes does not work out. If +that the case, you might want to circumvent the vendor by installing the latest +mainline kernel yourself and reporting the issue as outlined in this document; +just make sure to use really fresh kernel (see below). + + +.. note:: + + FIXME: Should we accept reports for issues with kernel images that are pretty + close to vanilla? But when are they close enough and how to put that line in + words? Maybe something like this? + + *Note: Some Linux kernel developers accept reports from vendor kernels that + are known to be close to upstream. That for example is often the case for + the kernels that Debian GNU/Linux Sid or Fedora Rawhide ship, which are + normally following mainline closely and carry only a few patches. So a + report with one of these might be accepted by the developers that need to + handle it. But if they do, depends heavily on the individual developers and + the issue at hand. That's why installing a mainline vanilla kernel is the + safe bet.* + + *Arch Linux, other Fedora releases, and openSUSE Tumbleweed often use quite + recent stable kernels that are pretty close to upstream, too. Some + developers accept bugs from them as well. But note that you normally should + avoid stable kernels for reporting issues and use a mainline kernel instead + (see below).* + + Are there any other major Linux distributions that should be mentioned here? + + +Issue of high priority? +----------------------- + + *See if the issue you are dealing with qualifies as regression, security + issue, or a really severe problem: those are 'issues of high priority' that + need special handling in some steps that are about to follow.* + +Linus Torvalds and the leading Linux kernel developers want to see some issues +fixed as soon as possible, hence there are 'issues of high priority' that get +handled slightly differently in the reporting process. Three type of cases +qualify: regressions, security issues, and really severe problems. + +You deal with a 'regression' if something that worked with an older version of +the Linux kernel does not work with a newer one or somehow works worse with it. +It thus is a regression when a WiFi driver that did a fine job with Linux 5.7 +somehow misbehaves with 5.8 or doesn't work at all. It's also a regression if +an application shows erratic behavior with a newer kernel, which might happen +due to incompatible changes in the interface between the kernel and the +userland (like procfs and sysfs). Significantly reduced performance or +increased power consumption also qualify as regression. But keep in mind: the +new kernel needs to be built with a configuration that is similar to the one +from the old kernel (see below how to achieve that). That's because the kernel +developers sometimes can not avoid incompatibilities when implementing new +features; but to avoid regressions such features have to be enabled explicitly +during build time configuration. + +What qualifies as security issue is left to your judgment. Consider reading +'Documentation/admin-guide/security-bugs.rst' before proceeding, as it +provides additional details how to best handle security issues. + +An issue is a 'really severe problem' when something totally unacceptably bad +happens. That's for example the case when a Linux kernel corrupts the data it's +handling or damages hardware it's running on. You're also dealing with a severe +issue when the kernel suddenly stops working with an error message ('kernel +panic') or without any farewell note at all. Note: do not confuse a 'panic' (a +fatal error where the kernel stop itself) with a 'Oops' (a recoverable error), +as the kernel remains running after the latter. + + +Check 'taint' flag +------------------ + + *Check if your kernel was 'tainted' when the issue occurred, as the event + that made the kernel set this flag might be causing the issue you face.* + +The kernel marks itself with a 'taint' flag when something happens that might +lead to follow-up errors that look totally unrelated. The issue you face might +be such an error if your kernel is tainted. That's why it's in your interest to +rule this out early before investing more time into this process. This is the +only reason why this step is here, as this process later will tell you to +install the latest mainline kernel; you will need to check the taint flag again +then, as that's when it matters because it's the kernel the report will focus +on. + +On a running system is easy to check if the kernel tainted itself: if ``cat +/proc/sys/kernel/tainted`` returns '0' then the kernel is not tainted and +everything is fine. Checking that file is impossible in some situations; that's +why the kernel also mentions the taint status when it reports an internal +problem (a 'kernel bug'), a recoverable error (a 'kernel Oops') or a +non-recoverable error before halting operation (a 'kernel panic'). Look near +the top of the error messages printed when one of these occurs and search for a +line starting with 'CPU:'. It should end with 'Not tainted' if the kernel was +not tainted when it noticed the problem; it was tainted if you see 'Tainted:' +followed by a few spaces and some letters. + +If your kernel is tainted, study 'Documentation/admin-guide/tainted-kernels.rst' +to find out why. Try to eliminate the reason. Often it's caused by one these +three things: + + 1. A recoverable error (a 'kernel Oops') occurred and the kernel tainted + itself, as the kernel knows it might misbehave in strange ways after that + point. In that case check your kernel or system log and look for a section + that starts with this:: + + Oops: 0000 [#1] SMP + + That's the first Oops since boot-up, as the '#1' between the brackets shows. + Every Oops and any other problem that happens after that point might be a + follow-up problem to that first Oops, even if both look totally unrelated. + Rule this out by getting rid of the cause for the first Oops and reproducing + the issue afterwards. Sometimes simply restarting will be enough, sometimes + a change to the configuration followed by a reboot can eliminate the Oops. + But don't invest too much time into this at this point of the process, as + the cause for the Oops might already be fixed in the newer Linux kernel + version you are going to install later in this process. + + 2. Your system uses a software that installs its own kernel modules, for + example Nvidia's proprietary graphics driver or VirtualBox. The kernel + taints itself when it loads such module from external sources (even if + they are Open Source): they sometimes cause errors in unrelated kernel + areas and thus might be causing the issue you face. You therefore have to + prevent those modules from loading when you want to report an issue to the + Linux kernel developers. Most of the time the easiest way to do that is: + temporarily uninstall such software including any modules they might have + installed. Afterwards reboot. + + 3. The kernel also taints itself when it's loading a module that resides in + the staging tree of the Linux kernel source. That's a special area for + code (mostly drivers) that does not yet fulfill the normal Linux kernel + quality standards. When you report an issue with such a module it's + obviously okay if the kernel is tainted; just make sure the module in + question is the only reason for the taint. If the issue happens in an + unrelated area reboot and temporarily block the module from being loaded + by specifying ``foo.blacklist=1`` as kernel parameter (replace 'foo' with + the name of the module in question). + + +Locate kernel area that causes the issue +---------------------------------------- + + *Locate the driver or kernel subsystem that seems to be causing the issue. + Find out how and where its developers expect reports. Note: most of the + time this won't be bugzilla.kernel.org, as issues typically need to be sent + by mail to a maintainer and a public mailing list.* + +It's crucial to send your report to the right people, as the Linux kernel is a +big project and most of its developers are only familiar with a small subset of +it. Quite a few programmers for example only care for just one driver, for +example one for a WiFi chip; its developer likely will only have small or no +knowledge about the internals of remote or unrelated "subsystems", like the TCP +stack, the PCIe/PCI subsystem, memory management or file systems. + +Problem is: the Linux kernel lacks a central bug tracker where you can simply +file your issue and make it reach the developers that need to know about it. +That's why you have to find the right place and way to report issues yourself. +You can do that with the help of a script (see below), but it mainly targets +kernel developers and experts. For everybody else the MAINTAINERS file is the +better place. + +How to read the MAINTAINERS file +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +To illustrate how to use the :ref:`MAINTAINERS <maintainers>` file, lets assume +the WiFi in your Laptop suddenly misbehaves after updating the kernel. In that +case it's likely an issue in the WiFi driver. Obviously it could also be some +code it builds upon, but unless you suspect something like that stick to the +driver. If it's really something else, the driver's developers will get the +right people involved. + +Sadly, there is no way to check which code is driving a particular hardware +component that is both universal and easy. + +In case of a problem with the WiFi driver you for example might want to look at +the output of ``lspci -k``, as it lists devices on the PCI/PCIe bus and the +kernel module driving it:: + + [user@something ~]$ lspci -k + [...] + 3a:00.0 Network controller: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter (rev 32) + Subsystem: Bigfoot Networks, Inc. Device 1535 + Kernel driver in use: ath10k_pci + Kernel modules: ath10k_pci + [...] + +But this approach won't work if your WiFi chip is connected over USB or some +other internal bus. In those cases you might want to check your WiFi manager or +the output of ``ip link``. Look for the name of the problematic network +interface, which might be something like 'wlp58s0'. This name can be used like +this to find the module driving it:: + + [user@something ~]$ realpath --relative-to=/sys/module/ /sys/class/net/wlp58s0/device/driver/module + ath10k_pci + +In case tricks like these don't bring you any further, try to search the +internet on how to narrow down the driver or subsystem in question. And if you +are unsure which it is: just try your best guess, somebody will help you if you +guessed poorly. + +Once you know the driver or subsystem, you want to search for it in the +MAINTAINERS file. In the case of 'ath10k_pci' you won't find anything, as the +name is too specific. Sometimes you will need to search on the net for help; +but before doing so, try a somewhat shorted or modified name when searching the +MAINTAINERS file, as then you might find something like this:: + + QUALCOMM ATHEROS ATH10K WIRELESS DRIVER + Mail: A. Some Human <shuman@example.com> + Mailing list: ath10k@lists.infradead.org + Status: Supported + Web-page: https://wireless.wiki.kernel.org/en/users/Drivers/ath10k + SCM: git git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git + Files: drivers/net/wireless/ath/ath10k/ + +Note: the line description will be abbreviations, if you read the plain +MAINTAINERS file found in the root of the Linux source tree. 'Mail:' for +example will be 'M:', 'Mailing list:' will be 'L', and 'Status:' will be 'S:'. +A section near the top of the file explains these and other abbreviations. + +First look at the line 'Status'. Ideally it should be 'Supported' or +'Maintained'. If it states 'Obsolete' then you are using some outdated approach +that was replaced by a newer solution you need to switch to. Sometimes the code +only has someone who provides 'Odd Fixes' when feeling motivated. And with +'Orphan' you are totally out of luck, as nobody takes care of the code anymore. +That only leaves these options: arrange yourself to live with the issue, fix it +yourself, or find a programmer somewhere willing to fix it. + +After checking the status, look for a line starting with 'bugs:': it will tell +you where to find a subsystem specific bug tracker to file your issue. The +example above does not have such a line. That is the case for most sections, as +Linux kernel development is completely driven by mail. Very few subsystems use +a bug tracker, and only some of those rely on bugzilla.kernel.org. + + +.. note:: + + FIXME: The old text took a totally different approach to bugzilla.kernel.org, + as it mentions it as the place to file issue for people that don't known how + to contact the appropriate people. The new one mentions it rarely; and when + it does like here, it warns users that it's often the wrong place to go. + + This approach was chosen as the main author of this document noticed quite a + few users (or even a lot?) get no reply to the bugs they file in bugzilla. + That's kind of expected, as quite a few (many? most?) of the maintainers + don't even get notified when reports for their subsystem get filed there. And + not getting a single reply to report is something that is just annoying for + users and might make them angry. Improving bugzilla.k.o would be an option, + but on the kernel and maintainers summit 2017 it was agreed on to first go + this route (sorry it took so long): it's easier to achieve and less + controversial, as putting additional burden on already overworked maintainers + is unlikely to get well received. + + +In this and many other cases you thus have to look for lines starting with +'Mail:' instead. Those mention the name and the email addresses for the +maintainers of the particular code. Also look for a line starting with 'Mailing +list:', which tells you the public mailing list where the code is developed. +Your report later needs to go by mail to those addresses. Additionally, for all +issue reports sent by email, make sure to add the Linux Kernel Mailing List +(LKML) <linux-kernel@vger.kernel.org> to CC. Don't omit either of the mailing +lists when sending your issue report by mail later! Maintainers are busy people +and might leave some work for other developers on the subsystem specific list; +and LKML is important to have one place where all issue reports can be found. + + +.. note:: + + FIXME: Above section tells users to always CC LKML. These days it's a kind of + "catch-all" list anyway, which nearly nobody seems to follow closely. So it + seems appropriate to go "all in" and make people send their reports here, + too, as everything (reports, fixes, ...) then can be found in one place (at + least for all reports sent by mail and all subsystems that CC LKML). + + Related: Should we create mailing list like 'linux-issues@vger.kernel.org' + and tell users above to always CC it when reporting issues? Then there would + be one central place reporters could search for existing reports (at least + for issues reported by mail) without getting regular LKML traffic mixed into + the results. + + +Finding the maintainers with the help of a script +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +For people that have the Linux sources at hand there is a second option to find +the proper place to report: the script 'scripts/get_maintainer.pl' which tries +to find all people to contact. It queries the MAINTAINERS file and needs to be +called with a path to the source code in question. For drivers compiled as +module if often can be found with a command like this:: + + $ modinfo ath10k_pci | grep filename | sed 's!/lib/modules/.*/kernel/!!; s!filename:!!; s!\.ko\(\|\.xz\)!!' + drivers/net/wireless/ath/ath10k/ath10k_pci.ko + +Pass parts of this to the script:: + + $ ./scripts/get_maintainer.pl -f drivers/net/wireless/ath/ath10k* + Some Human <shuman@example.com> (supporter:QUALCOMM ATHEROS ATH10K WIRELESS DRIVER) + Another S. Human <asomehuman@example.com> (maintainer:NETWORKING DRIVERS) + ath10k@lists.infradead.org (open list:QUALCOMM ATHEROS ATH10K WIRELESS DRIVER) + linux-wireless@vger.kernel.org (open list:NETWORKING DRIVERS (WIRELESS)) + netdev@vger.kernel.org (open list:NETWORKING DRIVERS) + linux-kernel@vger.kernel.org (open list) + +Don't sent your report to all of them. Send it to the maintainers, which the +script calls "supporter:"; additionally CC the most specific mailing list for +the code as well as the Linux Kernel Mailing List (LKML). In this case you thus +would need to send the report to 'Some Human <shuman@example.com>' with +'ath10k@lists.infradead.org' and 'linux-kernel@vger.kernel.org' in CC. + +Note: in case you cloned the Linux sources with git you might want to call +``get_maintainer.pl`` a second time with ``--git``. The script then will look +at the commit history to find which people recently worked on the code in +question, as they might be able to help. But use these results with care, as it +can easily send you in a wrong direction. That for example happens quickly in +areas rarely changed (like old or unmaintained drivers): sometimes such code is +modified during tree-wide cleanups by developers that do not care about the +particular driver at all. + + +Search for existing reports +--------------------------- + + *Search the archives of the bug tracker or mailing list in question + thoroughly for reports that might match your issue. Also check if you find + something with your favorite internet search engine or in the Linux Kernel + Mailing List (LKML) archives. If you find anything, join the discussion + instead of sending a new report.* + +Reporting an issue that someone else already brought forward is often a waste +of time for everyone involved, especially you as the reporter. So it's in your +own interest to thoroughly check if somebody reported the issue already. Thus +do not hurry with this step of the reporting process. Spending 30 to 60 minutes +or even more time can save you and others quite a lot of time and trouble. + +The best place to search is the bug tracker or the mailing list where your +report needs to be filed. You'll find quite a few of those lists on +`lore.kernel.org <https://lore.kernel.org/>`_, but some are hosted in +different places. That for example is the case for the ath10k WiFi driver used +as example in the previous step. But you'll often find the archives for these +lists easily on the net. Searching for 'archive ath10k@lists.infradead.org' for +example will quickly lead you to the `Info page for the ath10k mailing list +<https://lists.infradead.org/mailman/listinfo/ath10k>`_, which at the top links +to its `list archives <https://lists.infradead.org/pipermail/ath10k/>`_. + +Sadly this and quite a few other lists miss a way to search the archives. In +those cases use a regular internet search engine and add something like +'site:lists.infradead.org/pipermail/ath10k/' to your search terms, which limits +the results to the archives at that URL. + +Additionally, search the internet and the `Linux Kernel Mailing List (LKML) +archives <https://lore.kernel.org/lkml/>`_, as maybe the real culprit might be +in some other subsystem. Searching in `bugzilla.kernel.org +<https://bugzilla.kernel.org/>`_ might also be a good idea, but if you find +anything there keep in mind: most subsystems expect reports in different +places, hence those you find there might have not even reached the people +responsible for the subsystem in question. Nevertheless, the data there might +provide valuable insights. + +If you get flooded with results consider telling your search engine to limit +search timeframe to the past month or year. And wherever you search, make sure +to use good search terms; vary them a few times, too. While doing so try to +look at the issue from the perspective of someone else: that will help you to +come up with other words to use as search terms. Also make sure not to use too +many search terms at once. Remember to search with and without information like +the name of the kernel driver or the name of the affected hardware component. +But its exact brand name (say 'ASUS Red Devil Radeon RX 5700 XT Gaming OC') +often is not much helpful, as it is too specific. Instead try search terms like +the model line (Radeon 5700 or Radeon 5000) and the code name of the main chip +('Navi' or 'Navi10') with and without its manufacturer ('AMD'). + +In case you find an existing report about your issue, join the discussion, as +you might be able to provide valuable additional information. That can be +important even when a fix is prepared or in its final stages already, as +developers might look for people that can provide additional information or +test a proposed fix. Jump to the section 'Duties after the report went out' for +details on how to get properly involved. + + +Prepare for emergencies +----------------------- + + *Create a fresh backup and put system repair and restore tools at hand.* + +Reminder, you are dealing with computers, which sometimes do unexpected things, +especially if you fiddle with crucial parts like the kernel of its operating +system. That's what you are about to do in this process. Thus, make sure to +create a fresh backup; also ensure you have all tools at hand to repair or +reinstall the operating system as well as everything you need to restore the +backup. + + +Make sure your kernel doesn't get enhanced +------------------------------------------ + + *Ensure your system does not enhance its kernels by building additional + kernel modules on-the-fly, which solutions like DKMS might be doing locally + without your knowledge.* + +Your kernel must be 'vanilla' when reporting an issue, but stops being pure as +soon as it loads a kernel module not built from the sources used to compile the +kernel image itself. That's why you need to ensure your Linux kernel stays +vanilla by removing or disabling mechanisms like akmods and DKMS: those might +build additional kernel modules automatically, for example when your boot into +a newly installed Linux kernel the first time. Reboot after removing them and +any modules they installed. + +Note, you might not be aware that your system is using one of these solutions: +they often get set up silently when you install Nvidia's proprietary graphics +driver, VirtualBox, or other software that requires a some support from a +module not part of the Linux kernel. That why your might need to uninstall the +packages with such software to get rid of any 3rd party kernel module. + + +Ensure a healthy environment +---------------------------- + + *Make sure it's not the kernel's surroundings that are causing the issue + you face.* + +Problems that look a lot like a kernel issue are sometimes caused by build or +runtime environment. It's hard to rule out that problem completely, but you +should minimize it: + + * Use proven tools when building your kernel, as bugs in the compiler or the + binutils can cause the resulting kernel to misbehave. + + * Ensure your computer components run within their design specifications; + that's especially important for the main processor, the main memory, and the + motherboard. Therefore, stop undervolting or overclocking when facing a + potential kernel issue. + + * Try to make sure it's not faulty hardware that is causing your issue. Bad + main memory for example can result in a multitude of issues that will + manifest itself in problems looking like kernel issues. + + * If you're dealing with a filesystem issue, you might want to check the file + system in question with ``fsck``, as it might be damaged in a way that leads + to unexpected kernel behavior. + + * When dealing with a regression, make sure it's not something else that + changed in parallel to updating the kernel. The problem for example might be + caused by other software that was updated at the same time. It can also + happen that a hardware component coincidentally just broke when you rebooted + into a new kernel for the first time. Updating the systems BIOS or changing + something in the BIOS Setup can also lead to problems that on look a lot + like a kernel regression. + + +Document how to reproduce issue +------------------------------- + + *Write down coarsely how to reproduce the issue. If you deal with multiple + issues at once, create separate notes for each of them and make sure they + work independently on a freshly booted system. That's needed, as each issue + needs to get reported to the kernel developers separately, unless they are + strongly entangled.* + +If you deal with multiple issues at once, you'll have to report each of them +separately, as they might be handled by different developers. Describing +various issues in one report also makes it quite difficult for others to tear +it apart. Hence, only combine issues in one report if they are very strongly +entangled. + +Additionally, during the reporting process you will have to test if the issue +happens with other kernel versions. Therefore, it will make your work easier if +you know exactly how to reproduce an issue quickly on a freshly booted system. + +Note: it's often fruitless to report issues that only happened once, as they +might be caused by a bit flip due to cosmic radiation. That's why you should +try to rule that out by reproducing the issue before going further. Feel free +to ignore this advice if you are experienced enough to tell a one-time error +due to faulty hardware apart from a kernel issue that rarely happens and thus +is hard to reproduce. + + +Install a fresh kernel for testing +---------------------------------- + + *Install the latest Linux mainline kernel: that's where all issues get + fixed first, because it's the version line the kernel developers mainly + care about. Testing and reporting with the latest Linux stable kernel can + be an acceptable alternative in some situations, for example during the + merge window; but during that period you might want to suspend your efforts + till its end anyway.* + +Reporting an issue to the Linux kernel developers they fixed weeks or months +ago is annoying for them and wasting their and your time. That's why it's in +everybody's interest to check if the issue occurs with the latest codebase +before reporting it. + +In the scope of the Linux kernel the term 'latest' means: a kernel version +recently created from the main line of development, as this 'mainline' tree is +where developers first apply fixes; only after that are they are allowed to get +backported to older, still supported version lines called 'stable' and +'longterm' kernels. That's why you should check a recent mainline kernel, even +if you deal with an issue you only want to see fixed in an older version line. +Another reason: some fixes are only applied to mainline or recent version +lines, as it's too hard or risky to backport them to older versions. If that +the case, reporting the issue again is unlikely to change anything. + +Longterm kernels (sometimes called "LTS kernels") are therefore unsuitable for +testing; they simply are too distant from current development. Even the latest +Linux 'stable' kernel is a significant bit behind and thus better avoided. At +least most of the time, as sometimes a stable kernel can the best choice; but +in those situations you might want to wait a few days anyway: + +Choosing between mainline, stable and waiting +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Head over to `kernel.org <https://kernel.org/>`_ to decide which version to +use. Ignore the big yellow button that says 'Latest release' and look a little +lower for a table. At its top you'll see a line starting with 'mainline', which +most of the time will point to a pre-release with a version number like +'5.8-rc2'. If that's the case, you'll want to use this mainline kernel for +testing. Do not let that 'rc' scare you, these 'development kernels' are pretty +reliable — and you made a backup, as you were instructed above, didn't you? + +In about two out of every nine to ten weeks, 'mainline' might point you to a +proper release with a version number like '5.7'. If that happens, consider +suspending the reporting process until the first pre-release of the next +version (5.8-rc1) shows up on kernel.org. That's because the Linux development +cycle then is in its two-week long 'merge window'. The bulk of the changes and +all intrusive ones get merged for the next release during this time. It's a bit +more risky to use mainline during this period. Kernel developers are also often +quite busy then and might have no spare time to deal with issue reports. It's +also quite possible that one of the many changes applied during the merge +window fixes the issue you face; that's why you soon would have to retest with +a newer kernel version anyway, as outlined below in the section 'Duties after +the report went out'. + +That's why it might make sense to wait till the merge window is over. But don't +to that if you're dealing with something that shouldn't wait. In that case +consider obtaining the latest mainline kernel via git (see below) or use the +latest stable version offered on kernel.org. Using that is also acceptable in +case mainline for some reason does currently not work for you. An in general: +using it for reproducing the issue is also better than not reporting it issue +at all. + +How to obtain a fresh Linux kernel +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +You can use pre-built or self-compiled kernel for testing; if you choose the +latter approach, you can either obtain the source code using git or download it +as tar archive. + +Using a pre-compiled kernel for testing is often the quickest, easiest, and +safest way – especially is you are unfamiliar with the Linux kernel. But it +needs to be a vanilla kernel, which can be hard to come buy. You are in luck if +you are using a popular Linux distribution: for quite a few of them you'll find +repositories on the net that contain packages with the latest mainline or +stable kernels in vanilla fashion. It's totally okay to use these, just make +sure from the repository's documentation they are really vanilla. And ensure +the packages contain the latest versions as offered on kernel.org; they are +likely unsuitable if the package is older than a week, as new mainline and +stable kernels typically get released at least once a week. And be aware that +you might need to get build your own kernel later anyway when it comes to +helping test fixes, as described later in this document. + +Developers and experienced Linux users familiar with git are often best served +by obtaining the latest Linux kernel sources straight from the `official +development repository on kernel.org +<https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/>`_. +Those are likely a bit ahead of the latest mainline pre-release. Don't worry +about it: they are as reliable as a proper pre-release, unless the kernel's +development cycle is currently in the middle of a merge window. But even then +they are quite reliable. + +People unfamiliar with git are often best served by downloading the sources as +tarball from `kernel.org <https://kernel.org/>`_. + +How to actually build a kernel isnot described here, as many websites explain +the necessary steps already. If you are new to it, consider following one of +those how-to's that suggest to use ``make localmodconfig``, as that tries to +pick up the configuration of your current kernel and then tries to adjust it +somewhat for your system. That does not make the resulting kernel any better, +but quicker to compile. + + +Check 'taint' flag +------------------ + + *Ensure the kernel you just installed does not 'taint' itself when + running.* + +As outlined above in more detail already: the kernel sets a 'taint' flag when +something happens that can lead to follow-up errors that look totally +unrelated. That's why you need to check if the kernel you just installed does +not set this flag. And if it does, you in almost all the cases needs to +eliminate the reason for it before you reporting issues that occur with it. See +the section above for details how to do that. + + +Reproduce issue with the fresh kernel +------------------------------------- + + *Reproduce the issue with the kernel you just installed. If it doesn't show + up there, head over to the instructions for issues only happening with + stable and longterm kernels.* + +Check if the issue occurs with the fresh Linux kernel version you just +installed. If it was fixed there already, consider sticking with this version +line and abandoning your plan to report the issue. But keep in mind that other +users might still be plagued by it, as long as it's not fixed in either stable +and longterm version from kernel.org (and thus vendor kernels derived from +those). If you prefer to use one of those or just want to help their users, +head over to the section "Details about reporting issues only occurring in +older kernel version lines" below. + + +Optimize description to reproduce issue +--------------------------------------- + + *Optimize your notes: try to find and write the most straightforward way to + reproduce your issue. Make sure the end result has all the important + details, and at the same time is easy to read and understand for others + that hear about it for the first time. And if you learned something in this + process, consider searching again for existing reports about the issue.* + +An unnecessarily complex report will make it hard for others to understand your +report. Thus try to find a reproducer that's straight forward to describe and +thus easy to understand in written form. Include all important details, but at +the same time try to keep it as short as possible. + +In this in the previous steps you likely have learned a thing or two about the +issue you face. Use this knowledge and search again for existing reports +instead you can join. + + +Decode failure messages +----------------------- + +.. note:: + + FIXME: The text in this section is a placeholder for now and quite similar to + the old text found in 'Documentation/admin-guide/reporting-bugs.rst' + currently. It and the document it references are known to be outdated and + thus need to be revisited. Thus consider this note a request for help: if you + are familiar with this topic, please write a few lines that would fit here. + Alternatively, simply outline the current situation roughly to the main + authors of this document (see intro), as they might be able to write + something then. + + This section in the end should answer questions like "when is this actually + needed", "what .config options to ideally set earlier to make this step easy + or unnecessary?" (likely CONFIG_UNWINDER_ORC when it's available, otherwise + CONFIG_UNWINDER_FRAME_POINTER; but is there anything else needed?). + +.. + + *If the failure includes a stack dump, like an Oops does, consider decoding + it to find the offending line of code.* + +When the kernel detects an error, it will print a stack dump that allows to +identify the exact line of code where the issue happens. But that information +sometimes needs to get decoded to be readable, which is explained in +admin-guide/bug-hunting.rst. + + +Special care for regressions +---------------------------- + + *If your problem is a regression, try to narrow down when the issue was + introduced as much as possible.* + +Linux lead developer Linus Torvalds insists that the Linux kernel never +worsens, that's why he deems regressions as unacceptable and wants to see them +fixed quickly. That's why changes that introduced a regression are often +promptly reverted if the issue they cause can't get solved quickly any other +way. Reporting a regression is thus a bit like playing a kind of trump card to +get something quickly fixed. But for that to happen the change that's causing +the regression needs to be known. Normally it's up to the reporter to track +down the culprit, as maintainers often won't have the time or setup at hand to +reproduce it themselves. + +To find the change there is a process called 'bisection' which the document +'Documentation/admin-guide/bug-bisect.rst' describes in detail. That process +will often require you to build about ten to twenty kernel images, trying to +reproduce the issue with each of them before building the next. Yes, that takes +some time, but don't worry, it works a lot quicker than most people assume. +Thanks to a 'binary search' this will lead you to the one commit in the source +code management system that's causing the regression. Once you find it, search +the net for the subject of the change, its commit id and the shortened commit id +(the first 12 characters of the commit id). This will lead you to existing +reports about it, if there are any. + +Note, a bisection needs a bit of know-how, which not everyone has, and quite a +bit of effort, which not everyone is willing to invest. Nevertheless, it's +highly recommended performing a bisection yourself. If you really can't or +don't want to go down that route at least find out which mainline kernel +introduced the regression. If something for example breaks when switching from +5.5.15 to 5.8.4, then try at least all the mainline releases in that area (5.6, +5.7 and 5.8) to check when it first showed up. Unless you're trying to find a +regression in a stable or longterm kernel, avoid testing versions which number +has three sections (5.6.12, 5.7.8), as that makes the outcome hard to +interpret, which might render your testing useless. Once you found the major +version which introduced the regression, feel free to move on in the reporting +process. But keep in mind: it depends on the issue at hand if the developers +will be able to help without knowing the culprit. Sometimes they might +recognize from the report want went wrong and can fix it; other times they will +be unable to help unless you perform a bisection. + +When dealing with regressions make sure the issue you face is really caused by +the kernel and not by something else, as outlined above already. + +In the whole process keep in mind: an issue only qualifies as regression if the +older and the newer kernel got built with a similar configuration. The best way +to archive this: copy the configuration file (``.config``) from the old working +kernel freshly to each newer kernel version you try. Afterwards run ``make +oldnoconfig`` to adjust it for the needs of the new version without enabling +any new feature, as those are allowed to cause regressions. + + +Write and send the report +------------------------- + + *Start to compile the report by writing a detailed description about the + issue. Always mention a few things: the latest kernel version you installed + for reproducing, the Linux Distribution used, and your notes on how to + reproduce the issue. Ideally, make the kernel's build configuration + (.config) and the output from ``dmesg`` available somewhere on the net and + link to it. Include or upload all other information that might be relevant, + like the output/screenshot of an Oops or the output from ``lspci``. Once + you wrote this main part, insert a normal length paragraph on top of it + outlining the issue and the impact quickly. On top of this add one sentence + that briefly describes the problem and gets people to read on. Now give the + thing a descriptive title or subject that yet again is shorter. Then you're + ready to send or file the report like the MAINTAINERS file told you, unless + you are dealing with one of those 'issues of high priority': they need + special care which is explained in 'Special handling for high priority + issues' below.* + +Now that you have prepared everything it's time to write your report. How to do +that is partly explained by the three documents linked to in the preface above. +That's why this text will only mention a few of the essentials as well as +things specific to the Linux kernel. + +There is one thing that fits both categories: the most crucial parts of your +report are the title/subject, the first sentence, and the first paragraph. +Developers often get quite a lot of mail. They thus often just take a few +seconds to skim a mail before deciding to move on or look closer. Thus: the +better the top section of your report, the higher are the chances that someone +will look into it and help you. And that is why you should ignore them for now +and write the detailed report first. ;-) + +Things each report should mention +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Describe in detail how your issue happens with the fresh vanilla kernel you +installed. Try to include the step-by-step instructions you wrote and optimized +earlier that outline how you and ideally others can reproduce the issue; in +those rare cases where that's impossible try to describe what you did to +trigger it. + +Also include all the relevant information others might need to understand the +issue and its environment. What's actually needed depends a lot on the issue, +but there are some things you should include always: + + * the output from ``cat /proc/version``, which contains the Linux kernel + version number and the compiler it was built with. + + * the Linux distribution the machine is running (``hostnamectl | grep + "Operating System"``) + + * the architecture of the CPU and the operating system (``uname -mi``) + + * if you are dealing with a regression and performed a bisection, mention the + subject and the commit-id of the change that is causing it. + +In a lot of cases it's also wise to make two more things available to those +that read your report: + + * the configuration used for building your Linux kernel (the '.config' file) + + * the kernel's messages that you get from ``dmesg`` written to a file. Make + sure that it starts with a line like 'Linux version 5.8-1 + (foobar@example.com) (gcc (GCC) 10.2.1, GNU ld version 2.34) #1 SMP Mon Aug + 3 14:54:37 UTC 2020' If it's missing, then important messages from the first + boot phase already got discarded. In this case instead consider using + ``journalctl -b 0 -k``; alternatively you can also reboot, reproduce the + issue and call ``dmesg`` right afterwards. + +These two files are big, that's why it's a bad idea to put them directly into +your report. If you are filing the issue in a bug tracker then attach them to +the ticket. If you report the issue by mail do not attach them, as that makes +the mail too large; instead do one of these things: + + * Upload the files somewhere public (your website, a public file paste + service, a ticket created just for this purpose on `bugzilla.kernel.org + <https://bugzilla.kernel.org/>`_, ...) and include a link to them in your + report. Ideally use something where the files stay available for years, as + they could be useful to someone many years from now; this for example can + happen if five or ten years from now a developer works on some code that was + changed just to fix your issue. + + * Put the files aside and mention you will send them later in individual + replies to your own mail. Just remember to actually do that once the report + went out. ;-) + +Things that might be wise to provide +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Depending on the issue you might need to add more background data. Here are a +few suggestions what often is good to provide: + + * If you are dealing with a 'warning', an 'OOPS' or a 'panic' from the kernel, + include it. If you can't copy'n'paste it, try to capture a netconsole trace + or at least take a picture of the screen. + + * If the issue might be related to your computer hardware, mention what kind + of system you use. If you for example have problems with your graphics card, + mention its manufacturer, the card's model, and what chip is uses. If it's a + laptop mention its name, but try to make sure it's meaningful. 'Dell XPS 13' + for example is not, because it might be the one from 2012; that one looks + not that different from the one sold today, but apart from that the two have + nothing in common. Hence, in such cases add the exact model number, which + for example are '9380' or '7390' for XPS 13 models introduced during 2019. + Names like 'Lenovo Thinkpad T590' are also somewhat ambiguous: there are + variants of this laptop with and without a dedicated graphics chip, so try + to find the exact model name or specify the main components. + + * Mention the relevant software in use. If you have problems with loading + modules, you want to mention the versions of kmod, systemd, and udev in use. + If one of the DRM drivers misbehaves, you want to state the versions of + libdrm and Mesa; also specify your Wayland compositor or the X-Server and + its driver. If you have a filesystem issue, mention the version of + corresponding filesystem utilities (e2fsprogs, btrfs-progs, xfsprogs, ...). + + * Gather additional information from the kernel that might be of interest. The + output from ``lspci -nn`` will for example help others to identify what + hardware you use. If you have a problem with hardware you even might want to + make the output from ``sudo lspci -vvv`` available, as that provides + insights how the components were configured. For some issues it might be + good to include the contents of files like ``/proc/cpuinfo``, + ``/proc/ioports``, ``/proc/iomem``, ``/proc/modules``, or + ``/proc/scsi/scsi``. Some subsystem also offer tools to collect relevant + information. One such tool is ``alsa-info.sh`` `which the audio/sound + subsystem developers provide <https://www.alsa-project.org/wiki/AlsaInfo>`_. + +Those examples should give your some ideas of what data might be wise to +attach, but you have to think yourself what will be helpful for others to know. +Don't worry too much about forgetting something, as developers will ask for +additional details they need. But making everything important available from +the start increases the chance someone will take a closer look. + + +The important part: the head of your report +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Now that you have the detailed part of the report prepared let's get to the +most important section: the first few sentences. Thus go to the top, add +something like 'The detailed description:' before the part you just wrote and +insert two newlines at the top. Now write one normal length paragraph that +describes the issue roughly. Leave out all boring details and focus on the +crucial parts readers need to know to understand what this is all about; if you +think this bug affects a lot of users, mention this to get people interested. + +Once you did that insert two more lines at the top and write a one sentence +summary that explains quickly what the report is about. After that you have to +get even more abstract and write an even shorter subject/title for the report. + +Now that you have written this part take some time to optimize it, as it is the +most important parts of your report: a lot of people will only read this before +they decide if reading the rest is time well spent. + +Now send or file the report like the :ref:`MAINTAINERS <maintainers>` file told +you, unless it's one of those 'issues of high priority' outlined earlier: in +that case please read the next subsection first before sending the report on +its way. + +Special handling for high priority issues +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Reports for high priority issues need special handling. + +**Severe bugs**: make sure the subject or ticket title as well as the first +paragraph makes the severeness obvious. + +**Regressions**: If the issue is a regression add [REGRESSION] to the mail's +subject or the title in the bug-tracker. If you did not perform a bisection +mention at least the latest mainline version you tested that worked fine (say +5.7) and the oldest where the issue occurs (say 5.8). If you did a successful +bisection mention the commit id and subject of the change that causes the +regression. Also make sure to add the author of that change to your report; if +you need to file your bug in a bug-tracker forward the report to him in a +private mail and mention where your filed it. + +**Security issues**: for these issues your will have to evaluate if a +short-term risk to other users would arise if details were publicly disclosed. +If that's not the case simply proceed with reporting the issue as described. +For issues that bear such a risk you will need to adjust the reporting process +slightly: + + * If the MAINTAINERS file instructed you to report the issue by mail, do not + CC any public mailing lists. + + * If you were supposed to file the issue in a bug tracker make sure to mark + the ticket as 'private' or 'security issue'. If the bug tracker does not + offer a way to keep reports private, forget about it and send your report as + a private mail to the maintainers instead. + +In both cases make sure to also mail your report to the addresses the +MAINTAINERS file lists in the section 'security contact'. Ideally directly CC +them when sending the report by mail. If you filed it in a bug tracker, forward +the report's text to these addresses; but on top of it put a small note where +you mention that you filed it with a link to the ticket. + +See 'Documentation/admin-guide/security-bugs.rst' for more information. + + +Duties after the report went out +-------------------------------- + + *Wait for reactions and keep the thing rolling until you can accept the + outcome in one way or the other. Thus react publicly and in a timely manner + to any inquiries. Test proposed fixes. Do proactive testing: retest with at + least every first release candidate (RC) of a new mainline version and + report your results. Send friendly reminders if things stall. And try to + help yourself, if you don't get any help or if it's unsatisfying.* + +If your report was good and you are really lucky then one of the developers +might immediately spot what's causing the issue; they then might write a patch +to fix it, test it, and send it straight for integration in mainline while +tagging it for later backport to stable and longterm kernels that need it. Then +all you need to do is reply with a 'Thank you very much' and switch to a version +with the fix once it gets released. + +But this ideal scenario rarely happens. That's why the job is only starting +once you got the report out. What you'll have to do depends on the situations, +but often it will be the things listed below. But before digging into the +details, here are a few important things you need to keep in mind for this part +of the process. + + +General advice for further interactions +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +**Always reply in public**: When you filed the issue in a bug tracker, always +reply there and do not contact any of the developers privately about it. For +mailed reports always use the 'Reply-all' function when replying to any mails +you receive. That includes mails with any additional data you might want to add +to your report: go to your mail applications 'Sent' folder and use 'reply-all' +on your mail with the report. This approach will make sure the public mailing +list(s) and everyone else that gets involved over time stays in the loop; it +also keeps the mail thread intact, which among others is really important for +mailing lists to group all related mails together. + +There are just two situations where a comment in a bug tracker or a 'Reply-all' +is unsuitable: + + * Someone tells you to send something privately. + + * You were told to send something, but noticed it contains sensitive + information that needs to be kept private. In that case it's okay to send it + in private to the developer that asked for it. But note in the ticket or a + mail that you did that, so everyone else knows you honored the request. + +**Do research before asking for clarifications or help**: In this part of the +process someone might tell you to do something that requires a skill you might +not have mastered yet. For example, you might be asked to use some test tools +you never have heard of yet; or you might be asked to apply a patch to the +Linux kernel sources to test if it helps. In some cases it will be fine sending +a reply asking for instructions how to do that. But before going that route try +to find the answer own your own by searching the internet; alternatively +consider asking in other places for advice. For example ask a fried or post +about it to a chatroom or forum you normally hang out. + +**Be patient**: If you are really lucky you might get a reply to your report +within a few hours. But most of the time it will take longer, as maintainers +are scattered around the globe and thus might be in a different time zone – one +where they already enjoy their night away from keyboard. + +In general, kernel developers will take one to five business days to respond to +reports. Sometimes it will take longer, as they might be busy with the merge +windows, other work, visiting developer conferences, or simply enjoying a long +summer holiday. + +The 'issues of high priority' (see above for an explanation) are an exception +here: maintainers should address them as soon as possible; that's why you +should wait a week at maximum (or just two days if it's something urgent) +before sending a friendly reminder. + +Sometimes the maintainer might not be responding in a timely manner; other +times there might be disagreements, for example if an issue qualifies as +regression or not. In such cases raise your concerns on the mailing list and +ask others for public or private replies how to move on. If that fails, it +might be appropriate to get a higher authority involved. In case of a WiFi +driver that would be the wireless maintainers; if there are no higher level +maintainers or all else fails, it might be one of those rare situations where +it's okay to get Linus Torvalds involved. + +**Proactive testing**: Every time the first pre-release (the 'rc1') of a new +mainline kernel version gets released, go and check if the issue is fixed there +or if anything of importance changed. Mention the outcome in the ticket or in a +mail you sent as reply to your report (make sure it has all those in the CC +that up to that point participated in the discussion). This will show your +commitment and that you are willing to help. It also tells developers if the +issue persists and makes sure they do not forget about it. A few other +occasional retests (for example with rc3, rc5 and the final) are also a good +idea, but only report your results if something relevant changed or if you are +writing something anyway. + +With all these general things off the table let's get into the details of how +to help to get issues resolved once they were reported. + +Inquires and testing request +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Here are your duties in case you got replies to your report: + +**Check who you deal with**: Most of the time it will be the maintainer or a +developer of the particular code area that will respond to your report. But as +issues are normally reported in public it could be anyone that's replying — +including people that want to help, but in the end might guide you totally off +track with their questions or requests. That rarely happens, but it's one of +many reasons why it's wise to quickly run an internet search to see who you're +interacting with. By doing this you also get aware if your report was heard by +the right people, as a reminder to the maintainer (see below) might be in order +later if discussion fades out without leading to a satisfying solution for the +issue. + +**Inquiries for data**: Often you will be asked to test something or provide +additional details. Try to provide the requested information soon, as you have +the attention of someone that might help and risk losing it the longer you +wait; that outcome is even likely if you do not provide the information within +a few business days. + +**Requests for testing**: When you are asked to test a diagnostic patch or a +possible fix, try to test it in timely manner, too. But do it properly and make +sure to not rush it: mixing things up can happen easily and can lead to a lot +of confusion for everyone involved. A common mistake for example is thinking a +proposed patch with a fix was applied, but in fact wasn't. Things like that +happen even to experienced testers occasionally, but they most of the time will +notice when the kernel with the fix behaves just as one without it. + +What to do when nothing of substance happens +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Some reports will not get any reaction from the responsible Linux kernel +developers; or a discussion around the issue evolved, but faded out with +nothing of substance coming out of it. + +In these cases wait two (better: three) weeks before sending a friendly +reminder: maybe the maintainer was just away from keyboard for a while when +your report arrived or had something more important to take care of. When +writing the reminder, kindly ask if anything else from your side is needed to +get the ball running somehow. If the report got out by mail, do that in the +first lines of a mail that is a reply to your initial mail (see above) which +includes a full quote of the original report below: that's on of those few +situations where such a 'TOFU' (Text Over, Fullquote Under) is the right +approach, as then all the recipients will have the details at hand immediately +in the proper order. + +After the reminder wait three more weeks for replies. If you still don't get a +proper reaction, you first should reconsider your approach. Did you maybe try +to reach out to the wrong people? Was the report maybe offensive or so +confusing that people decided to completely stay away from it? The best way to +rule out such factors: show the report to one or two people familiar with FLOSS +issue reporting and ask for their opinion. Also ask them for their advice how +to move forward. That might mean: prepare a better report and make those people +review it before you send it out. Such an approach is totally fine; just +mention that this is the second and improved report on the issue and include a +link to the first report. + +If the report was proper you can send a second reminder; in it ask for advice +why the report did not get any replies. A good moment for this second reminder +mail is shortly after the first pre-release (the 'rc1') of a new Linux kernel +version got published, as you should retest and provide a status update at that +point anyway (see above). + +If the second reminder again results in no reaction within a week, try to +contact a higher-level maintainer asking for advice: even busy maintainers by +then should at least have sent some kind of acknowledgment. + +Remember to prepare yourself for a disappointment: maintainers ideally should +react somehow to every issue report, but they are only obliged to fix those +'issues of high priority' outlined earlier. So don't be too devastating if you +get a reply along the lines of 'thanks for the report, I have more important +issues to deal with currently and won't have time to look into this for the +foreseeable future'. + +It's also possible that after some discussion in the bug tracker or on a list +nothing happens anymore and reminders don't help to motivate anyone to work out +a fix. Such situations can be devastating, but is within the cards when it +comes to Linux kernel development. This and several other reasons for not +getting help are explained in 'Why some issues won't get any reaction or remain +unfixed after being reported' near the end of this document. + +Don't get devastated if you don't find any help or if the issue in the end does +not get solved: the Linux kernel is FLOSS and thus you can still help yourself. +You for example could try to find others that are affected and team up with +them to get the issue resolved. Such a team could prepare a fresh report +together that mentions how many you are and why this is something that in your +option should get fixed. Maybe together you can also narrow down the root cause +or the change that introduced a regression, which often makes developing a fix +easier. And with a bit of luck there might be someone in the team that knows a +bit about programming and might be able to write a fix. + + +Details about reporting issues only occurring in older kernel version lines +--------------------------------------------------------------------------- + +This subsection provides details for steps you need to take if you could not +reproduce your issue with a mainline kernel, but want to see it fixed in older +version lines (aka stable and longterm kernels). + +Some fixes are too complex +~~~~~~~~~~~~~~~~~~~~~~~~~~ + + *Prepare yourself for the possibility that going through the next few steps + might not get the issue solved in older releases: the fix might be too big + or risky to get backported there.* + +Even small and seemingly obvious code-changes sometimes introduce new and +totally unexpected problems. The maintainers of the stable and longterm kernels +are very aware of that and thus only apply changes to these kernels that are +within rules outlined in 'Documentation/process/stable-kernel-rules.rst'. + +Complex or risky changes for example do not qualify and thus only get applied +to mainline. Other fixes are easy to get backported to the newest stable and +longterm kernels, but too risky to integrate into older ones. So be aware the +fix you are hoping for might be one of those that won't be backported to the +version line your care about. In that case you'll have no other choice then to +live with the issue or switch to a newer Linux version, unless you want to +patch the fix into your kernels yourself. + +Make sure the particular version line still gets support +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + + *Check if the kernel developers still maintain the Linux kernel version + line you care about: go to the front page of kernel.org and make sure it + mentions the latest release of the particular version line without an + '[EOL]' tag.* + +Most kernel version lines only get supported for about three months, as +maintaining them longer is quite a lot of work. Hence, only one per year is +chosen and gets supported for at least two years (often six). That's why you +need to check if the kernel developers still support the version line you care +for. + +Note, if kernel.org lists two 'stable' version lines on the front page, you +should consider switching to the newer one and forget about the older one: +support for it is likely to be abandoned soon. Then it will get a "end-of-life" +(EOL) stamp. Version lines that reached that point still get mentioned on the +kernel.org front page for a week or two, but are unsuitable for testing and +reporting. + +Search stable mailing list +~~~~~~~~~~~~~~~~~~~~~~~~~~ + + *Check the archives of the Linux stable mailing list for existing reports.* + +Maybe the issue you face is already known and was fixed or is about to. Hence, +`search the archives of the Linux stable mailing list +<https://lore.kernel.org/stable/>`_ for reports about an issue like yours. If +you find any matches, consider joining the discussion, unless the fix is +already finished and scheduled to get applied soon. + +Reproduce issue with the newest release +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + + *Install the latest release from the particular version line as a vanilla + kernel. Ensure this kernel is not tainted and still shows the problem, as + the issue might have already been fixed there.* + +Before investing any more time in this process you want to check if the issue +was already fixed in the latest release of version line you're interested in. +This kernel needs to be vanilla and shouldn't be tainted before the issue +happens, as detailed outlined already above in the process of testing mainline. + +Check code history and search for existing discussions +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + + *Search the Linux kernel version control system for the change that fixed + the issue in mainline, as its commit message might tell you if the fix is + scheduled for backporting already. If you don't find anything that way, + search the appropriate mailing lists for posts that discuss such an issue + or peer-review possible fixes; then check the discussions if the fix was + deemed unsuitable for backporting. If backporting was not considered at + all, join the newest discussion, asking if it's in the cards.* + +In a lot of cases the issue you deal with will have happened with mainline, but +got fixed there. The commit that fixed it would need to get backported as well +to get the issue solved. That's why you want to search for it or any +discussions abound it. + + * First try to find the fix in the Git repository that holds the Linux kernel + sources. You can do this with the web interfaces `on kernel.org + <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/>`_ + or its mirror `on GitHub <https://github.com/torvalds/linux>`_; if you have + a local clone you alternatively can search on the command line with ``git + log --grep=<pattern>``. + + If you find the fix, look if the commit message near the end contains a + 'stable tag' that looks like this: + + Cc: <stable@vger.kernel.org> # 5.4+ + + If that's case the developer marked the fix safe for backporting to version + line 5.4 and later. Most of the time it's getting applied there within two + weeks, but sometimes it takes a bit longer. + + * If the commit doesn't tell you anything or if you can't find the fix, look + again for discussions about the issue. Search the net with your favorite + internet search engine as well as the archives for the `Linux kernel + developers mailing list <https://lore.kernel.org/lkml/>`_. Also read the + section `Locate kernel area that causes the issue` above and follow the + instructions to find the subsystem in question: its bug tracker or mailing + list archive might have the answer you are looking for. + + * If you see a proposed fix, search for it in the version control system as + outlined above, as the commit might tell you if a backport can be expected. + + * Check the discussions for any indicators the fix might be too risky to get + backported to the version line you care about. If that's the case you have + to live with the issue or switch to the kernel version line where the fix + got applied. + + * If the fix doesn't contain a stable tag and backporting was not discussed, + join the discussion: mention the version where you face the issue and that + you would like to see it fixed, if suitable. + +Check if it's a regression specific to stable or longterm kernels +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + + *Check if you're dealing with a regression that was never present in + mainline by installing the first release of the version line you care + about. If the issue doesn't show up with it, you basically need to report + the issue with this version like you would report a problem with mainline + (see above). This ideally includes a bisection followed by a search for + existing reports on the net; with the help of the subject and the two + relevant commit-ids. If that doesn't turn up anything, write the report; CC + or forward the report to the stable maintainers, the stable mailing list, + and those who authored the change. Include the shortened commit-id if you + found the change that causes it.* + +Sometimes you won't find anything in the previous step: the issue you face +might have never occurred in mainline, as it is caused by some change that is +incomplete or not correctly applied. To check this, install the first release +from version line you care about, e.g., if you care about 5.4.x, install 5.4. + +If the issue doesn't show itself there, it's a regression specific to the +particular version line. In that case you need to report it like an issue +happening in mainline, like the last few steps in the main section in the above +outline. + +One of them suggests doing a bisection, which you are strongly advised to do in +this case. After finding the culprit, search the net for existing reports +again: not only search for the exact subject and the commit-id (proper and +shortened to twelve characters) of the change, but also for the commit-id +(proper and shortened) mentioned as 'Upstream commit' in the commit message. + +Write the report; just keep a few specialties in mind: CC or forward the report +to the stable maintainers, the stable mailing list, which the :ref:`MAINTAINERS +<maintainers>` file mentions in the section "STABLE BRANCH". If you performed a +successful bisection, CC the author of the change and include its subject and +the shortened commit-id. + +Ask for advice +~~~~~~~~~~~~~~ + + *One of the former steps should lead to a solution. If that doesn't work + out, ask the maintainers for the subsystem that seems to be causing the + issue for advice; CC the mailing list for the particular subsystem as well + as the stable mailing list.* + +If the previous three steps didn't get you closer to a solution there is only +one option left: ask for advice. Do that in a mail you sent to the maintainers +for the subsystem where the issue seems to have its roots; CC the mailing list +for the subsystem as well as the stable mailing list the :ref:`MAINTAINERS +<maintainers>` file mention in the section "STABLE BRANCH". + + +Why some issues won't get any reaction or remain unfixed after being reported +============================================================================= + +When reporting a problem to the Linux developers, be aware only 'issues of high +priority' (regressions, security issues, severe problems) are definitely going +to get resolved. The maintainers or if all else fails Linus Torvalds himself +will make sure of that. They and the other kernel developers will fix a lot of +other issues as well. But be aware that sometimes they can't or won't help; and +sometimes there isn't even anyone to send a report to. + +This is best explained with kernel developers that contribute to the Linux +kernel in their spare time. Quite a few of the drivers in the kernel were +written by such programmers, often because they simply wanted to make their +hardware usable on their favorite operating system. + +These programmers most of the time will happily fix problems other people +report. But nobody can force them to do, as they are contributing voluntarily. + +Then there are situations where such developers really want to fix an issue, +but can't: sometimes they lack hardware programming documentation to do so. +This often happens when the publicly available docs are superficial or the +driver was written with the help of reverse engineering. + +Sooner or later spare time developers will also stop caring for the driver. +Maybe their test hardware broke, got replaced by something more fancy, or is so +old that it's something you don't find much outside of computer museums +anymore. Sometimes developer stops caring for their code and Linux at all, as +something different in their life became way more important. In some cases +nobody is willing to take over the job as maintainer – and nobody can be forced +to, as contributing to the Linux kernel is done on a voluntary basis. Abandoned +drivers nevertheless remain in the kernel: they are still useful for people and +removing would be a regression. + +The situation is not that different with developers that are paid for their +work on the Linux kernel. Those contribute most changes these days. But their +employers sooner or later also stop caring for their code or make its +programmer focus on other things. Hardware vendors for example earn their money +mainly by selling new hardware; quite a few of them hence are not investing +much time and energy in maintaining a Linux kernel driver for something they +stopped selling years ago. Enterprise Linux distributors often care for a +longer time period, but in new versions often leave support for old and rare +hardware aside to limit the scope. Often spare time contributors take over once +a company orphans some code, but as mentioned above: sooner or later they will +leave the code behind, too. + +Priorities are another reason why some issues are not fixed, as maintainers +quite often are forced to set those, as time to work on Linux is limited. +That's true for spare time or the time employers grant their developers to +spend on maintenance work on the upstream kernel. Sometimes maintainers also +get overwhelmed with reports, even if a driver is working nearly perfectly. To +not get completely stuck, the programmer thus might have no other choice than +to prioritize issue reports and reject some of them. + +But don't worry too much about all of this, a lot of drivers have active +maintainers who are quite interested in fixing as many issues as possible. + + +Closing words +============= + +Compared with other Free/Libre & Open Source Software it's hard to report +issues to the Linux kernel developers: the length and complexity of this +document and the implications between the lines illustrate that. But that's how +it is for now. The main author of this text hopes documenting the state of the +art will lay some groundwork to improve the situation over time. diff --git a/Documentation/admin-guide/security-bugs.rst b/Documentation/admin-guide/security-bugs.rst index c32eb786201c..82e29837d589 100644 --- a/Documentation/admin-guide/security-bugs.rst +++ b/Documentation/admin-guide/security-bugs.rst @@ -21,7 +21,7 @@ understand and fix the security vulnerability. As it is with any bug, the more information provided the easier it will be to diagnose and fix. Please review the procedure outlined in -:doc:`reporting-bugs` if you are unclear about what +'Documentation/admin-guide/reporting-issues.rst' if you are unclear about what information is helpful. Any exploit code is very helpful and will not be released without consent from the reporter unless it has already been made public. diff --git a/Documentation/admin-guide/sysctl/abi.rst b/Documentation/admin-guide/sysctl/abi.rst index ac87eafdb54f..77b1d1b2ad42 100644 --- a/Documentation/admin-guide/sysctl/abi.rst +++ b/Documentation/admin-guide/sysctl/abi.rst @@ -28,7 +28,7 @@ vsyscall32 (x86) Determines whether the kernels maps a vDSO page into 32-bit processes; can be set to 1 to enable, or 0 to disable. Defaults to enabled if -``CONFIG_COMPAT_VDSO`` is set, disabled otherwide. +``CONFIG_COMPAT_VDSO`` is set, disabled otherwise. This controls the same setting as the ``vdso32`` kernel boot parameter. diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index d4b32cc32bb7..1d56a6b73a4e 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -14,7 +14,7 @@ For general info and legal blurb, please look in :doc:`index`. ------------------------------------------------------------------------------ This file contains documentation for the sysctl files in -``/proc/sys/kernel/`` and is valid for Linux kernel version 2.2. +``/proc/sys/kernel/``. The files in this directory can be used to tune and monitor miscellaneous and general things in the operation of the Linux @@ -879,7 +879,7 @@ The default value is 127. perf_event_mlock_kb =================== -Control size of per-cpu ring buffer not counted agains mlock limit. +Control size of per-cpu ring buffer not counted against mlock limit. The default value is 512 + 1 page @@ -1095,8 +1095,8 @@ Enables/disables scheduler statistics. Enabling this feature incurs a small amount of overhead in the scheduler but is useful for debugging and performance tuning. -sched_util_clamp_min: -===================== +sched_util_clamp_min +==================== Max allowed *minimum* utilization. @@ -1106,8 +1106,8 @@ It means that any requested uclamp.min value cannot be greater than sched_util_clamp_min, i.e., it is restricted to the range [0:sched_util_clamp_min]. -sched_util_clamp_max: -===================== +sched_util_clamp_max +==================== Max allowed *maximum* utilization. @@ -1117,8 +1117,8 @@ It means that any requested uclamp.max value cannot be greater than sched_util_clamp_max, i.e., it is restricted to the range [0:sched_util_clamp_max]. -sched_util_clamp_min_rt_default: -================================ +sched_util_clamp_min_rt_default +=============================== By default Linux is tuned for performance. Which means that RT tasks always run at the highest frequency and most capable (highest capacity) CPU (in @@ -1336,7 +1336,7 @@ ORed together. The letters are seen in "Tainted" line of Oops reports. ====== ===== ============================================================== 1 `(P)` proprietary module was loaded 2 `(F)` module was force loaded - 4 `(S)` SMP kernel oops on an officially SMP incapable processor + 4 `(S)` kernel running on an out of specification system 8 `(R)` module was force unloaded 16 `(M)` processor reported a Machine Check Exception (MCE) 32 `(B)` bad page referenced or some unexpected page flags diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index f455fa00c00f..e0cf17ad2ae5 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -146,7 +146,7 @@ This should be used on systems where stalls for minor page faults are an acceptable trade for large contiguous free memory. Set to 0 to prevent compaction from moving pages that are unevictable. Default value is 1. On CONFIG_PREEMPT_RT the default value is 0 in order to avoid a page fault, due -to compaction, which would block the task from becomming active until the fault +to compaction, which would block the task from becoming active until the fault is resolved. diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst index f718a2eaf1f6..ceeed7b0798d 100644 --- a/Documentation/admin-guide/tainted-kernels.rst +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -84,7 +84,7 @@ Bit Log Number Reason that got the kernel tainted === === ====== ======================================================== 0 G/P 1 proprietary module was loaded 1 _/F 2 module was force loaded - 2 _/S 4 SMP kernel oops on an officially SMP incapable processor + 2 _/S 4 kernel running on an out of specification system 3 _/R 8 module was force unloaded 4 _/M 16 processor reported a Machine Check Exception (MCE) 5 _/B 32 bad page referenced or some unexpected page flags @@ -116,10 +116,23 @@ More detailed explanation for tainting 1) ``F`` if any module was force loaded by ``insmod -f``, ``' '`` if all modules were loaded normally. - 2) ``S`` if the oops occurred on an SMP kernel running on hardware that - hasn't been certified as safe to run multiprocessor. - Currently this occurs only on various Athlons that are not - SMP capable. + 2) ``S`` if the kernel is running on a processor or system that is out of + specification: hardware has been put into an unsupported configuration, + therefore proper execution cannot be guaranteed. + Kernel will be tainted if, for example: + + - on x86: PAE is forced through forcepae on intel CPUs (such as Pentium M) + which do not report PAE but may have a functional implementation, an SMP + kernel is running on non officially capable SMP Athlon CPUs, MSRs are + being poked at from userspace. + - on arm: kernel running on certain CPUs (such as Keystone 2) without + having certain kernel features enabled. + - on arm64: there are mismatched hardware features between CPUs, the + bootloader has booted CPUs in different modes. + - certain drivers are being used on non supported architectures (such as + scsi/snic on something else than x86_64, scsi/ips on non + x86/x86_64/itanium, have broken firmware settings for the + irqchip/irq-gic on arm64 ...). 3) ``R`` if a module was force unloaded by ``rmmod -f``, ``' '`` if all modules were unloaded normally. diff --git a/Documentation/arm/features.rst b/Documentation/arm/features.rst new file mode 100644 index 000000000000..7414ec03dd15 --- /dev/null +++ b/Documentation/arm/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features arm diff --git a/Documentation/arm/index.rst b/Documentation/arm/index.rst index 5fc072dd0c5e..a2e9e1bba7b9 100644 --- a/Documentation/arm/index.rst +++ b/Documentation/arm/index.rst @@ -23,6 +23,8 @@ ARM Architecture vlocks porting + features + SoC-specific documents ====================== diff --git a/Documentation/arm/sunxi.rst b/Documentation/arm/sunxi.rst index 0c536ae1d7c2..b85d1e2f2d47 100644 --- a/Documentation/arm/sunxi.rst +++ b/Documentation/arm/sunxi.rst @@ -158,3 +158,13 @@ SunXi family * User Manual https://linux-sunxi.org/images/4/46/Allwinner_H6_V200_User_Manual_V1.1.pdf + + - Allwinner H616 + + * Datasheet + + https://linux-sunxi.org/images/b/b9/H616_Datasheet_V1.0_cleaned.pdf + + * User Manual + + https://linux-sunxi.org/images/2/24/H616_User_Manual_V1.0_cleaned.pdf diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst index bbd9cf54db6c..87821662eeb2 100644 --- a/Documentation/arm64/elf_hwcaps.rst +++ b/Documentation/arm64/elf_hwcaps.rst @@ -1,3 +1,5 @@ +.. _elf_hwcaps_index: + ================ ARM64 ELF hwcaps ================ diff --git a/Documentation/arm64/features.rst b/Documentation/arm64/features.rst new file mode 100644 index 000000000000..dfa4cb3cd3ef --- /dev/null +++ b/Documentation/arm64/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features arm64 diff --git a/Documentation/arm64/index.rst b/Documentation/arm64/index.rst index 937634c49979..97d65ba12a35 100644 --- a/Documentation/arm64/index.rst +++ b/Documentation/arm64/index.rst @@ -24,6 +24,8 @@ ARM64 Architecture tagged-address-abi tagged-pointers + features + .. only:: subproject and html Indices diff --git a/Documentation/arm64/perf.rst b/Documentation/arm64/perf.rst index 9c76a97baf28..b567f177d385 100644 --- a/Documentation/arm64/perf.rst +++ b/Documentation/arm64/perf.rst @@ -1,5 +1,7 @@ .. SPDX-License-Identifier: GPL-2.0 +.. _perf_index: + ===================== Perf Event Attributes ===================== diff --git a/Documentation/conf.py b/Documentation/conf.py index ed2b43ec7754..6a767294887e 100644 --- a/Documentation/conf.py +++ b/Documentation/conf.py @@ -39,7 +39,7 @@ needs_sphinx = '1.3' extensions = ['kerneldoc', 'rstFlatTable', 'kernel_include', 'kfigure', 'sphinx.ext.ifconfig', 'automarkup', 'maintainers_include', 'sphinx.ext.autosectionlabel', - 'kernel_abi'] + 'kernel_abi', 'kernel_feat'] # # cdomain is badly broken in Sphinx 3+. Leaving it out generates *most* @@ -112,6 +112,9 @@ if major >= 3: else: extensions.append('cdomain') + if major == 1 and minor < 7: + sys.stderr.write('WARNING: Sphinx 1.7 or greater will be required as of ' + 'the 5.12 release\n') # Ensure that autosectionlabel will produce unique names autosectionlabel_prefix_document = True diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 6d26c5c6ac48..160e710d992f 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -531,7 +531,9 @@ For printing bitmap and its derivatives such as cpumask and nodemask, %*pb outputs the bitmap with field width as the number of bits and %*pbl output the bitmap as range list with field width as the number of bits. -Passed by reference. +The field width is passed by value, the bitmap is passed by reference. +Helper macros cpumask_pr_args() and nodemask_pr_args() are available to ease +printing cpumask and nodemask. Flags bitfields such as page flags, gfp_flags --------------------------------------------- diff --git a/Documentation/dev-tools/coccinelle.rst b/Documentation/dev-tools/coccinelle.rst index 74c5e6aeeff5..9c454de5a7f7 100644 --- a/Documentation/dev-tools/coccinelle.rst +++ b/Documentation/dev-tools/coccinelle.rst @@ -224,14 +224,21 @@ you may want to use:: rm -f err.log export COCCI=scripts/coccinelle/misc/irqf_oneshot.cocci - make coccicheck DEBUG_FILE="err.log" MODE=report SPFLAGS="--profile --show-trying" M=./drivers/mfd/arizona-irq.c + make coccicheck DEBUG_FILE="err.log" MODE=report SPFLAGS="--profile --show-trying" M=./drivers/mfd err.log will now have the profiling information, while stdout will provide some progress information as Coccinelle moves forward with work. +NOTE: + DEBUG_FILE support is only supported when using coccinelle >= 1.0.2. +Currently, DEBUG_FILE support is only available to check folders, and +not single files. This is because checking a single file requires spatch +to be called twice leading to DEBUG_FILE being set both times to the same value, +giving rise to an error. + .cocciconfig support -------------------- diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst index 2b68addaadcd..0bd6d0e1ca6b 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -330,7 +330,7 @@ using something like insmod or modprobe. The module is called ``test_kasan``. ~~~~~~~~~~~~~ With ``CONFIG_KUNIT`` built-in, ``CONFIG_KASAN_KUNIT_TEST`` can be built-in -on any architecure that supports KASAN. These and any other KUnit +on any architecture that supports KASAN. These and any other KUnit tests enabled will run and print the results at boot as a late-init call. @@ -351,5 +351,5 @@ converted to KUnit. These tests can be run only as a module with ``CONFIG_KASAN`` built-in. The type of error expected and the function being run is printed before the expression expected to give an error. Then the error is printed, if found, and that test -should be interpretted to pass only if the error was the one expected +should be interpreted to pass only if the error was the one expected by the test. diff --git a/Documentation/dev-tools/kcov.rst b/Documentation/dev-tools/kcov.rst index 8548b0b04e43..d2c4c27e1702 100644 --- a/Documentation/dev-tools/kcov.rst +++ b/Documentation/dev-tools/kcov.rst @@ -243,7 +243,7 @@ handles as they don't belong to a particular subsystem. The bytes 4-7 are currently reserved and must be zero. In the future the number of bytes used for the subsystem or handle ids might be increased. -When a particular userspace proccess collects coverage via a common +When a particular userspace process collects coverage via a common handle, kcov will collect coverage for each code section that is annotated to use the common handle obtained as kcov_handle from the current task_struct. However non common handles allow to collect coverage diff --git a/Documentation/dev-tools/kgdb.rst b/Documentation/dev-tools/kgdb.rst index 77b688e6a254..43456244651a 100644 --- a/Documentation/dev-tools/kgdb.rst +++ b/Documentation/dev-tools/kgdb.rst @@ -63,10 +63,9 @@ will want to turn on ``CONFIG_DEBUG_INFO`` which is called It is advised, but not required, that you turn on the ``CONFIG_FRAME_POINTER`` kernel option which is called :menuselection:`Compile the kernel with frame pointers` in the config menu. This option inserts code -to into the compiled executable which saves the frame information in -registers or on the stack at different points which allows a debugger -such as gdb to more accurately construct stack back traces while -debugging the kernel. +into the compiled executable which saves the frame information in registers +or on the stack at different points which allows a debugger such as gdb to +more accurately construct stack back traces while debugging the kernel. If the architecture that you are using supports the kernel option ``CONFIG_STRICT_KERNEL_RWX``, you should consider turning it off. This diff --git a/Documentation/devicetree/bindings/submitting-patches.rst b/Documentation/devicetree/bindings/submitting-patches.rst index 0aab2b3f16d0..68129ff09967 100644 --- a/Documentation/devicetree/bindings/submitting-patches.rst +++ b/Documentation/devicetree/bindings/submitting-patches.rst @@ -25,7 +25,8 @@ I. For patch submitters make dt_binding_check - See ../writing-schema.rst for more details about schema and tools setup. + See Documentation/devicetree/writing-schema.rst for more details about + schema and tools setup. 3) DT binding files should be dual licensed. The preferred license tag is (GPL-2.0-only OR BSD-2-Clause). diff --git a/Documentation/doc-guide/kernel-doc.rst b/Documentation/doc-guide/kernel-doc.rst index 52a87ab4c99f..79aaa55d6bcf 100644 --- a/Documentation/doc-guide/kernel-doc.rst +++ b/Documentation/doc-guide/kernel-doc.rst @@ -247,12 +247,12 @@ It is possible to document nested structs and unions, like:: struct { int memb1; int memb2; - } + }; struct { void *memb3; int memb4; - } - } + }; + }; union { struct { int memb1; diff --git a/Documentation/doc-guide/sphinx.rst b/Documentation/doc-guide/sphinx.rst index 896478baf570..2fb2ff297d69 100644 --- a/Documentation/doc-guide/sphinx.rst +++ b/Documentation/doc-guide/sphinx.rst @@ -375,7 +375,7 @@ image format use SVG (:ref:`svg_image_example`):: SVG image example -The kernel figure (and image) directive support **DOT** formated files, see +The kernel figure (and image) directive support **DOT** formatted files, see * DOT: http://graphviz.org/pdf/dotguide.pdf * Graphviz: http://www.graphviz.org/content/dot-language diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index f357f3eb400c..08c32952fce3 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -29,6 +29,7 @@ available subsections can be seen below. infiniband frame-buffer regulator + reset iio/index input usb/index diff --git a/Documentation/driver-api/mtd/intel-spi.rst b/Documentation/driver-api/mtd/intel-spi.rst index 0e6d9cd5388d..0465f6879262 100644 --- a/Documentation/driver-api/mtd/intel-spi.rst +++ b/Documentation/driver-api/mtd/intel-spi.rst @@ -52,7 +52,7 @@ Linux. 16384+0 records out 8388608 bytes (8.4 MB) copied, 10.0269 s, 837 kB/s - 6) Verify the backup: + 6) Verify the backup:: # sha1sum /dev/mtd0ro bios.bak fdbb011920572ca6c991377c4b418a0502668b73 /dev/mtd0ro @@ -66,7 +66,7 @@ Linux. # flash_erase /dev/mtd0 0 0 Erasing 4 Kibyte @ 7ff000 -- 100 % complete - 8) Once completed without errors you can write the new BIOS image: + 8) Once completed without errors you can write the new BIOS image:: # dd if=MNW2MAX1.X64.0092.R01.1605221712.bin of=/dev/mtd0 diff --git a/Documentation/driver-api/mtd/spi-nor.rst b/Documentation/driver-api/mtd/spi-nor.rst index 1f0437676762..4a3adca417fd 100644 --- a/Documentation/driver-api/mtd/spi-nor.rst +++ b/Documentation/driver-api/mtd/spi-nor.rst @@ -34,7 +34,8 @@ Before this framework, the layer is like:: ------------------------ SPI NOR chip - After this framework, the layer is like: +After this framework, the layer is like:: + MTD ------------------------ SPI NOR framework @@ -45,7 +46,8 @@ Before this framework, the layer is like:: ------------------------ SPI NOR chip - With the SPI NOR controller driver (Freescale QuadSPI), it looks like: +With the SPI NOR controller driver (Freescale QuadSPI), it looks like:: + MTD ------------------------ SPI NOR framework diff --git a/Documentation/driver-api/reset.rst b/Documentation/driver-api/reset.rst new file mode 100644 index 000000000000..84e03d7039cc --- /dev/null +++ b/Documentation/driver-api/reset.rst @@ -0,0 +1,221 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +==================== +Reset controller API +==================== + +Introduction +============ + +Reset controllers are central units that control the reset signals to multiple +peripherals. +The reset controller API is split into two parts: +the `consumer driver interface <#consumer-driver-interface>`__ (`API reference +<#reset-consumer-api>`__), which allows peripheral drivers to request control +over their reset input signals, and the `reset controller driver interface +<#reset-controller-driver-interface>`__ (`API reference +<#reset-controller-driver-api>`__), which is used by drivers for reset +controller devices to register their reset controls to provide them to the +consumers. + +While some reset controller hardware units also implement system restart +functionality, restart handlers are out of scope for the reset controller API. + +Glossary +-------- + +The reset controller API uses these terms with a specific meaning: + +Reset line + + Physical reset line carrying a reset signal from a reset controller + hardware unit to a peripheral module. + +Reset control + + Control method that determines the state of one or multiple reset lines. + Most commonly this is a single bit in reset controller register space that + either allows direct control over the physical state of the reset line, or + is self-clearing and can be used to trigger a predetermined pulse on the + reset line. + In more complicated reset controls, a single trigger action can launch a + carefully timed sequence of pulses on multiple reset lines. + +Reset controller + + A hardware module that provides a number of reset controls to control a + number of reset lines. + +Reset consumer + + Peripheral module or external IC that is put into reset by the signal on a + reset line. + +Consumer driver interface +========================= + +This interface provides an API that is similar to the kernel clock framework. +Consumer drivers use get and put operations to acquire and release reset +controls. +Functions are provided to assert and deassert the controlled reset lines, +trigger reset pulses, or to query reset line status. + +When requesting reset controls, consumers can use symbolic names for their +reset inputs, which are mapped to an actual reset control on an existing reset +controller device by the core. + +A stub version of this API is provided when the reset controller framework is +not in use in order to minimize the need to use ifdefs. + +Shared and exclusive resets +--------------------------- + +The reset controller API provides either reference counted deassertion and +assertion or direct, exclusive control. +The distinction between shared and exclusive reset controls is made at the time +the reset control is requested, either via devm_reset_control_get_shared() or +via devm_reset_control_get_exclusive(). +This choice determines the behavior of the API calls made with the reset +control. + +Shared resets behave similarly to clocks in the kernel clock framework. +They provide reference counted deassertion, where only the first deassert, +which increments the deassertion reference count to one, and the last assert +which decrements the deassertion reference count back to zero, have a physical +effect on the reset line. + +Exclusive resets on the other hand guarantee direct control. +That is, an assert causes the reset line to be asserted immediately, and a +deassert causes the reset line to be deasserted immediately. + +Assertion and deassertion +------------------------- + +Consumer drivers use the reset_control_assert() and reset_control_deassert() +functions to assert and deassert reset lines. +For shared reset controls, calls to the two functions must be balanced. + +Note that since multiple consumers may be using a shared reset control, there +is no guarantee that calling reset_control_assert() on a shared reset control +will actually cause the reset line to be asserted. +Consumer drivers using shared reset controls should assume that the reset line +may be kept deasserted at all times. +The API only guarantees that the reset line can not be asserted as long as any +consumer has requested it to be deasserted. + +Triggering +---------- + +Consumer drivers use reset_control_reset() to trigger a reset pulse on a +self-deasserting reset control. +In general, these resets can not be shared between multiple consumers, since +requesting a pulse from any consumer driver will reset all connected +peripherals. + +The reset controller API allows requesting self-deasserting reset controls as +shared, but for those only the first trigger request causes an actual pulse to +be issued on the reset line. +All further calls to this function have no effect until all consumers have +called reset_control_rearm(). +For shared reset controls, calls to the two functions must be balanced. +This allows devices that only require an initial reset at any point before the +driver is probed or resumed to share a pulsed reset line. + +Querying +-------- + +Only some reset controllers support querying the current status of a reset +line, via reset_control_status(). +If supported, this function returns a positive non-zero value if the given +reset line is asserted. +The reset_control_status() function does not accept a +`reset control array <#reset-control-arrays>`__ handle as its input parameter. + +Optional resets +--------------- + +Often peripherals require a reset line on some platforms but not on others. +For this, reset controls can be requested as optional using +devm_reset_control_get_optional_exclusive() or +devm_reset_control_get_optional_shared(). +These functions return a NULL pointer instead of an error when the requested +reset control is not specified in the device tree. +Passing a NULL pointer to the reset_control functions causes them to return +quietly without an error. + +Reset control arrays +-------------------- + +Some drivers need to assert a bunch of reset lines in no particular order. +devm_reset_control_array_get() returns an opaque reset control handle that can +be used to assert, deassert, or trigger all specified reset controls at once. +The reset control API does not guarantee the order in which the individual +controls therein are handled. + +Reset controller driver interface +================================= + +Drivers for reset controller modules provide the functionality necessary to +assert or deassert reset signals, to trigger a reset pulse on a reset line, or +to query its current state. +All functions are optional. + +Initialization +-------------- + +Drivers fill a struct :c:type:`reset_controller_dev` and register it with +reset_controller_register() in their probe function. +The actual functionality is implemented in callback functions via a struct +:c:type:`reset_control_ops`. + +API reference +============= + +The reset controller API is documented here in two parts: +the `reset consumer API <#reset-consumer-api>`__ and the `reset controller +driver API <#reset-controller-driver-api>`__. + +Reset consumer API +------------------ + +Reset consumers can control a reset line using an opaque reset control handle, +which can be obtained from devm_reset_control_get_exclusive() or +devm_reset_control_get_shared(). +Given the reset control, consumers can call reset_control_assert() and +reset_control_deassert(), trigger a reset pulse using reset_control_reset(), or +query the reset line status using reset_control_status(). + +.. kernel-doc:: include/linux/reset.h + :internal: + +.. kernel-doc:: drivers/reset/core.c + :functions: reset_control_reset + reset_control_assert + reset_control_deassert + reset_control_status + reset_control_acquire + reset_control_release + reset_control_rearm + reset_control_put + of_reset_control_get_count + of_reset_control_array_get + devm_reset_control_array_get + reset_control_get_count + +Reset controller driver API +--------------------------- + +Reset controller drivers are supposed to implement the necessary functions in +a static constant structure :c:type:`reset_control_ops`, allocate and fill out +a struct :c:type:`reset_controller_dev`, and register it using +devm_reset_controller_register(). + +.. kernel-doc:: include/linux/reset-controller.h + :internal: + +.. kernel-doc:: drivers/reset/core.c + :functions: of_reset_simple_xlate + reset_controller_register + reset_controller_unregister + devm_reset_controller_register + reset_controller_add_lookup diff --git a/Documentation/features/list-arch.sh b/Documentation/features/list-arch.sh index 1ec47c3bb5fa..e73aa35848f0 100755 --- a/Documentation/features/list-arch.sh +++ b/Documentation/features/list-arch.sh @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # # Small script that visualizes the kernel feature support status # of an architecture. @@ -7,18 +8,4 @@ ARCH=${1:-$(uname -m | sed 's/x86_64/x86/' | sed 's/i386/x86/')} -cd $(dirname $0) -echo "#" -echo "# Kernel feature support matrix of the '$ARCH' architecture:" -echo "#" - -for F in */*/arch-support.txt; do - SUBSYS=$(echo $F | cut -d/ -f1) - N=$(grep -h "^# Feature name:" $F | cut -c25-) - C=$(grep -h "^# Kconfig:" $F | cut -c25-) - D=$(grep -h "^# description:" $F | cut -c25-) - S=$(grep -hv "^#" $F | grep -w $ARCH | cut -d\| -f3) - - printf "%10s/%-22s:%s| %35s # %s\n" "$SUBSYS" "$N" "$S" "$C" "$D" -done - +$(dirname $0)/../../scripts/get_feat.pl list --arch $ARCH diff --git a/Documentation/features/locking/queued-rwlocks/arch-support.txt b/Documentation/features/locking/queued-rwlocks/arch-support.txt index 5c6bcfcf8e1f..4dd5e554873f 100644 --- a/Documentation/features/locking/queued-rwlocks/arch-support.txt +++ b/Documentation/features/locking/queued-rwlocks/arch-support.txt @@ -22,7 +22,7 @@ | nios2: | TODO | | openrisc: | ok | | parisc: | TODO | - | powerpc: | TODO | + | powerpc: | ok | | riscv: | TODO | | s390: | TODO | | sh: | TODO | diff --git a/Documentation/features/locking/queued-spinlocks/arch-support.txt b/Documentation/features/locking/queued-spinlocks/arch-support.txt index b55e420a34ea..b16d4f71e5ce 100644 --- a/Documentation/features/locking/queued-spinlocks/arch-support.txt +++ b/Documentation/features/locking/queued-spinlocks/arch-support.txt @@ -22,7 +22,7 @@ | nios2: | TODO | | openrisc: | ok | | parisc: | TODO | - | powerpc: | TODO | + | powerpc: | ok | | riscv: | TODO | | s390: | TODO | | sh: | TODO | diff --git a/Documentation/features/seccomp/seccomp-filter/arch-support.txt b/Documentation/features/seccomp/seccomp-filter/arch-support.txt index c688aba22a8d..eb3d74092c61 100644 --- a/Documentation/features/seccomp/seccomp-filter/arch-support.txt +++ b/Documentation/features/seccomp/seccomp-filter/arch-support.txt @@ -11,7 +11,7 @@ | arm: | ok | | arm64: | ok | | c6x: | TODO | - | csky: | TODO | + | csky: | ok | | h8300: | TODO | | hexagon: | TODO | | ia64: | TODO | @@ -25,7 +25,7 @@ | powerpc: | ok | | riscv: | ok | | s390: | ok | - | sh: | TODO | + | sh: | ok | | sparc: | TODO | | um: | ok | | x86: | ok | diff --git a/Documentation/features/time/context-tracking/arch-support.txt b/Documentation/features/time/context-tracking/arch-support.txt index 266c81e8a721..52aea275aab7 100644 --- a/Documentation/features/time/context-tracking/arch-support.txt +++ b/Documentation/features/time/context-tracking/arch-support.txt @@ -11,7 +11,7 @@ | arm: | ok | | arm64: | ok | | c6x: | TODO | - | csky: | TODO | + | csky: | ok | | h8300: | TODO | | hexagon: | TODO | | ia64: | TODO | diff --git a/Documentation/features/time/virt-cpuacct/arch-support.txt b/Documentation/features/time/virt-cpuacct/arch-support.txt index 56b372da6b01..e51f3af38e31 100644 --- a/Documentation/features/time/virt-cpuacct/arch-support.txt +++ b/Documentation/features/time/virt-cpuacct/arch-support.txt @@ -11,7 +11,7 @@ | arm: | ok | | arm64: | ok | | c6x: | TODO | - | csky: | TODO | + | csky: | ok | | h8300: | TODO | | hexagon: | TODO | | ia64: | ok | diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index 98f59a864242..7be9b46d85d9 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -113,7 +113,7 @@ Documentation for filesystem implementations. sysv-fs tmpfs ubifs - ubifs-authentication.rst + ubifs-authentication udf virtiofs vfat diff --git a/Documentation/filesystems/mount_api.rst b/Documentation/filesystems/mount_api.rst index d7f53d62b5bb..eb358a00be27 100644 --- a/Documentation/filesystems/mount_api.rst +++ b/Documentation/filesystems/mount_api.rst @@ -774,7 +774,7 @@ process the parameters it is given. should just be set to lie inside the low-to-high range. If all is good, true is returned. If the table is invalid, errors are - logged to dmesg and false is returned. + logged to the kernel log buffer and false is returned. * :: @@ -782,7 +782,7 @@ process the parameters it is given. This performs some validation checks on a parameter description. It returns true if the description is good and false if it is not. It will - log errors to dmesg if validation fails. + log errors to the kernel log buffer if validation fails. * :: diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 533c79e8d2cd..e5fa972d4c76 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -546,6 +546,7 @@ encoded manner. The codes are the following: nh no huge page advise flag mg mergable advise flag bt arm64 BTI guarded page + mt arm64 MTE allocation tags are enabled == ======================================= Note that there is no guarantee that every flag and associated mnemonic will diff --git a/Documentation/ia64/features.rst b/Documentation/ia64/features.rst new file mode 100644 index 000000000000..d7226fdcf5f8 --- /dev/null +++ b/Documentation/ia64/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features ia64 diff --git a/Documentation/ia64/index.rst b/Documentation/ia64/index.rst index 4bdfe28067ee..761f2154dfa2 100644 --- a/Documentation/ia64/index.rst +++ b/Documentation/ia64/index.rst @@ -15,3 +15,5 @@ IA-64 Architecture irq-redir mca serial + + features diff --git a/Documentation/index.rst b/Documentation/index.rst index 57719744774c..5888e8a7272f 100644 --- a/Documentation/index.rst +++ b/Documentation/index.rst @@ -160,7 +160,7 @@ implementation. ia64/index m68k/index mips/index - nios2/nios2 + nios2/index openrisc/index parisc/index powerpc/index diff --git a/Documentation/m68k/features.rst b/Documentation/m68k/features.rst new file mode 100644 index 000000000000..5107a2119472 --- /dev/null +++ b/Documentation/m68k/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features m68k diff --git a/Documentation/m68k/index.rst b/Documentation/m68k/index.rst index b89cb6a86d9b..0f890dbb5fe2 100644 --- a/Documentation/m68k/index.rst +++ b/Documentation/m68k/index.rst @@ -10,6 +10,8 @@ m68k Architecture kernel-options buddha-driver + features + .. only:: subproject and html Indices diff --git a/Documentation/mips/features.rst b/Documentation/mips/features.rst new file mode 100644 index 000000000000..1973d729b29a --- /dev/null +++ b/Documentation/mips/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features mips diff --git a/Documentation/mips/index.rst b/Documentation/mips/index.rst index 35cceea4e8bc..037f85a08fe3 100644 --- a/Documentation/mips/index.rst +++ b/Documentation/mips/index.rst @@ -11,6 +11,8 @@ MIPS-specific Documentation booting ingenic-tcu + features + .. only:: subproject and html Indices diff --git a/Documentation/networking/device_drivers/ethernet/3com/vortex.rst b/Documentation/networking/device_drivers/ethernet/3com/vortex.rst index eab10fc6da5c..e89e4192af88 100644 --- a/Documentation/networking/device_drivers/ethernet/3com/vortex.rst +++ b/Documentation/networking/device_drivers/ethernet/3com/vortex.rst @@ -374,8 +374,8 @@ steps you should take: email address will be in the driver source or in the MAINTAINERS file. - The contents of your report will vary a lot depending upon the - problem. If it's a kernel crash then you should refer to the - admin-guide/reporting-bugs.rst file. + problem. If it's a kernel crash then you should refer to + 'Documentation/admin-guide/reporting-issues.rst'. But for most problems it is useful to provide the following: diff --git a/Documentation/nios2/features.rst b/Documentation/nios2/features.rst new file mode 100644 index 000000000000..8449e63f69b2 --- /dev/null +++ b/Documentation/nios2/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features nios2 diff --git a/Documentation/nios2/index.rst b/Documentation/nios2/index.rst new file mode 100644 index 000000000000..4468fe1a1037 --- /dev/null +++ b/Documentation/nios2/index.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================== +Nios II Specific Documentation +============================== + +.. toctree:: + :maxdepth: 2 + :numbered: + + nios2 + features diff --git a/Documentation/openrisc/features.rst b/Documentation/openrisc/features.rst new file mode 100644 index 000000000000..3f7c40d219f2 --- /dev/null +++ b/Documentation/openrisc/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features openrisc diff --git a/Documentation/openrisc/index.rst b/Documentation/openrisc/index.rst index 748b3eea1707..6879f998b87a 100644 --- a/Documentation/openrisc/index.rst +++ b/Documentation/openrisc/index.rst @@ -10,6 +10,8 @@ OpenRISC Architecture openrisc_port todo + features + .. only:: subproject and html Indices diff --git a/Documentation/parisc/features.rst b/Documentation/parisc/features.rst new file mode 100644 index 000000000000..501d7c450037 --- /dev/null +++ b/Documentation/parisc/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features parisc diff --git a/Documentation/parisc/index.rst b/Documentation/parisc/index.rst index aa3ee0470425..240685751825 100644 --- a/Documentation/parisc/index.rst +++ b/Documentation/parisc/index.rst @@ -10,6 +10,8 @@ PA-RISC Architecture debugging registers + features + .. only:: subproject and html Indices diff --git a/Documentation/powerpc/features.rst b/Documentation/powerpc/features.rst new file mode 100644 index 000000000000..aeae73df86b0 --- /dev/null +++ b/Documentation/powerpc/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features powerpc diff --git a/Documentation/powerpc/index.rst b/Documentation/powerpc/index.rst index 6ec64b0d5257..bf5f1a2bdbdf 100644 --- a/Documentation/powerpc/index.rst +++ b/Documentation/powerpc/index.rst @@ -34,6 +34,8 @@ powerpc vas-api vcpudispatch_stats + features + .. only:: subproject and html Indices diff --git a/Documentation/process/clang-format.rst b/Documentation/process/clang-format.rst index 82676e5a7c6e..1d089a847c1b 100644 --- a/Documentation/process/clang-format.rst +++ b/Documentation/process/clang-format.rst @@ -97,7 +97,7 @@ it can be very useful. There are integrations for many popular text editors. For some of them, like vim, emacs, BBEdit and Visual Studio you can find support built-in. -For instructions, read the appropiate section at: +For instructions, read the appropriate section at: https://clang.llvm.org/docs/ClangFormat.html diff --git a/Documentation/process/embargoed-hardware-issues.rst b/Documentation/process/embargoed-hardware-issues.rst index 43cdc67e4f8e..6f8f36e10e8b 100644 --- a/Documentation/process/embargoed-hardware-issues.rst +++ b/Documentation/process/embargoed-hardware-issues.rst @@ -152,7 +152,7 @@ The disclosing party should provide a list of contacts for all other entities who have already been, or should be, informed about the issue. This serves several purposes: - - The list of disclosed entities allows communication accross the + - The list of disclosed entities allows communication across the industry, e.g. other OS vendors, HW vendors, etc. - The disclosed entities can be contacted to name experts who should diff --git a/Documentation/process/howto.rst b/Documentation/process/howto.rst index 20c9e07e09a4..7a5c105e34d4 100644 --- a/Documentation/process/howto.rst +++ b/Documentation/process/howto.rst @@ -348,11 +348,10 @@ tool. For details on how to use the kernel bugzilla, please see: https://bugzilla.kernel.org/page.cgi?id=faq.html -The file :ref:`admin-guide/reporting-bugs.rst <reportingbugs>` -in the main kernel source directory has a good -template for how to report a possible kernel bug, and details what kind -of information is needed by the kernel developers to help track down the -problem. +The file 'Documentation/admin-guide/reporting-issues.rst' in the main kernel +source directory has a good template for how to report a possible kernel bug, +and details what kind of information is needed by the kernel developers to help +track down the problem. Managing bug reports diff --git a/Documentation/process/kernel-docs.rst b/Documentation/process/kernel-docs.rst index 64786e50026c..22d9ace5df2a 100644 --- a/Documentation/process/kernel-docs.rst +++ b/Documentation/process/kernel-docs.rst @@ -90,7 +90,7 @@ On-line docs :Date: 2008 :Keywords: patches, review process, types of submissions, basic rules, case studies :Description: This paper gives several experience values on what types of patches - there are and how likley they get merged. + there are and how likely they get merged. :Abstract: [...]. This paper examines some common problems for submitting larger changes and some strategies to avoid problems. @@ -328,7 +328,7 @@ On-line docs block devices, hardware interrupts, scsi, DMA, access to user memory, memory allocation, timers. :Description: A guide designed to help you get up to speed on the - concepts that are not intuitevly obvious, and to document the internal + concepts that are not intuitively obvious, and to document the internal structures of Linux. * Title: **Dynamic Kernels: Modularized Device Drivers** diff --git a/Documentation/process/submitting-patches.rst b/Documentation/process/submitting-patches.rst index 83d9a82055a7..fb8261a4be30 100644 --- a/Documentation/process/submitting-patches.rst +++ b/Documentation/process/submitting-patches.rst @@ -404,6 +404,8 @@ then you just add a line saying:: using your real name (sorry, no pseudonyms or anonymous contributions.) This will be done for you automatically if you use ``git commit -s``. +Reverts should also include "Signed-off-by". ``git revert -s`` does that +for you. Some people also put extra tags at the end. They'll just be ignored for now, but you can do this to mark internal company procedures or just diff --git a/Documentation/riscv/features.rst b/Documentation/riscv/features.rst new file mode 100644 index 000000000000..c70ef6ac2368 --- /dev/null +++ b/Documentation/riscv/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features riscv diff --git a/Documentation/riscv/index.rst b/Documentation/riscv/index.rst index fa33bffd8992..6e6e39482502 100644 --- a/Documentation/riscv/index.rst +++ b/Documentation/riscv/index.rst @@ -9,6 +9,8 @@ RISC-V architecture pmu patch-acceptance + features + .. only:: subproject and html Indices diff --git a/Documentation/s390/features.rst b/Documentation/s390/features.rst new file mode 100644 index 000000000000..57c296a9d8f3 --- /dev/null +++ b/Documentation/s390/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features s390 diff --git a/Documentation/s390/index.rst b/Documentation/s390/index.rst index cf71df5776b4..b10ca9192557 100644 --- a/Documentation/s390/index.rst +++ b/Documentation/s390/index.rst @@ -19,6 +19,8 @@ s390 Architecture text_files + features + .. only:: subproject and html Indices diff --git a/Documentation/sh/features.rst b/Documentation/sh/features.rst new file mode 100644 index 000000000000..f722af3b6c99 --- /dev/null +++ b/Documentation/sh/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features sh diff --git a/Documentation/sh/index.rst b/Documentation/sh/index.rst index 7b9a79a28167..c64776738cf6 100644 --- a/Documentation/sh/index.rst +++ b/Documentation/sh/index.rst @@ -11,6 +11,8 @@ SuperH Interfaces Guide new-machine register-banks + features + Memory Management ================= diff --git a/Documentation/sparc/features.rst b/Documentation/sparc/features.rst new file mode 100644 index 000000000000..c0c92468b0fe --- /dev/null +++ b/Documentation/sparc/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features sparc diff --git a/Documentation/sparc/index.rst b/Documentation/sparc/index.rst index 71cff621f243..ae884224eec2 100644 --- a/Documentation/sparc/index.rst +++ b/Documentation/sparc/index.rst @@ -9,3 +9,5 @@ Sparc Architecture adi oradax/oracle-dax + + features diff --git a/Documentation/sphinx/automarkup.py b/Documentation/sphinx/automarkup.py index 3e81ebab26ed..953b24b6e2b4 100644 --- a/Documentation/sphinx/automarkup.py +++ b/Documentation/sphinx/automarkup.py @@ -53,6 +53,8 @@ RE_typedef = re.compile(r'\b(typedef)\s+([a-zA-Z_]\w+)', flags=ascii_p3) # RE_doc = re.compile(r'\bDocumentation(/[\w\-_/]+)(\.\w+)*') +RE_namespace = re.compile(r'^\s*..\s*c:namespace::\s*(\S+)\s*$') + # # Reserved C words that we should skip when cross-referencing # @@ -70,6 +72,8 @@ Skipfuncs = [ 'open', 'close', 'read', 'write', 'fcntl', 'mmap', 'select', 'poll', 'fork', 'execve', 'clone', 'ioctl', 'socket' ] +c_namespace = '' + def markup_refs(docname, app, node): t = node.astext() done = 0 @@ -128,30 +132,38 @@ def markup_func_ref_sphinx3(docname, app, match): # # Go through the dance of getting an xref out of the C domain # - target = match.group(2) + base_target = match.group(2) target_text = nodes.Text(match.group(0)) xref = None - if not (target in Skipfuncs or target in Skipnames): - for class_s, reftype_s in zip(class_str, reftype_str): - lit_text = nodes.literal(classes=['xref', 'c', class_s]) - lit_text += target_text - pxref = addnodes.pending_xref('', refdomain = 'c', - reftype = reftype_s, - reftarget = target, modname = None, - classname = None) - # - # XXX The Latex builder will throw NoUri exceptions here, - # work around that by ignoring them. - # - try: - xref = cdom.resolve_xref(app.env, docname, app.builder, - reftype_s, target, pxref, - lit_text) - except NoUri: - xref = None + possible_targets = [base_target] + # Check if this document has a namespace, and if so, try + # cross-referencing inside it first. + if c_namespace: + possible_targets.insert(0, c_namespace + "." + base_target) - if xref: - return xref + if base_target not in Skipnames: + for target in possible_targets: + if target not in Skipfuncs: + for class_s, reftype_s in zip(class_str, reftype_str): + lit_text = nodes.literal(classes=['xref', 'c', class_s]) + lit_text += target_text + pxref = addnodes.pending_xref('', refdomain = 'c', + reftype = reftype_s, + reftarget = target, modname = None, + classname = None) + # + # XXX The Latex builder will throw NoUri exceptions here, + # work around that by ignoring them. + # + try: + xref = cdom.resolve_xref(app.env, docname, app.builder, + reftype_s, target, pxref, + lit_text) + except NoUri: + xref = None + + if xref: + return xref return target_text @@ -179,34 +191,39 @@ def markup_c_ref(docname, app, match): # # Go through the dance of getting an xref out of the C domain # - target = match.group(2) + base_target = match.group(2) target_text = nodes.Text(match.group(0)) xref = None - if not ((match.re == RE_function and target in Skipfuncs) - or (target in Skipnames)): - lit_text = nodes.literal(classes=['xref', 'c', class_str[match.re]]) - lit_text += target_text - pxref = addnodes.pending_xref('', refdomain = 'c', - reftype = reftype_str[match.re], - reftarget = target, modname = None, - classname = None) - # - # XXX The Latex builder will throw NoUri exceptions here, - # work around that by ignoring them. - # - try: - xref = cdom.resolve_xref(app.env, docname, app.builder, - reftype_str[match.re], target, pxref, - lit_text) - except NoUri: - xref = None - # - # Return the xref if we got it; otherwise just return the plain text. - # - if xref: - return xref - else: - return target_text + possible_targets = [base_target] + # Check if this document has a namespace, and if so, try + # cross-referencing inside it first. + if c_namespace: + possible_targets.insert(0, c_namespace + "." + base_target) + + if base_target not in Skipnames: + for target in possible_targets: + if not (match.re == RE_function and target in Skipfuncs): + lit_text = nodes.literal(classes=['xref', 'c', class_str[match.re]]) + lit_text += target_text + pxref = addnodes.pending_xref('', refdomain = 'c', + reftype = reftype_str[match.re], + reftarget = target, modname = None, + classname = None) + # + # XXX The Latex builder will throw NoUri exceptions here, + # work around that by ignoring them. + # + try: + xref = cdom.resolve_xref(app.env, docname, app.builder, + reftype_str[match.re], target, pxref, + lit_text) + except NoUri: + xref = None + + if xref: + return xref + + return target_text # # Try to replace a documentation reference of the form Documentation/... with a @@ -239,7 +256,18 @@ def markup_doc_ref(docname, app, match): else: return nodes.Text(match.group(0)) +def get_c_namespace(app, docname): + source = app.env.doc2path(docname) + with open(source) as f: + for l in f: + match = RE_namespace.search(l) + if match: + return match.group(1) + return '' + def auto_markup(app, doctree, name): + global c_namespace + c_namespace = get_c_namespace(app, name) # # This loop could eventually be improved on. Someday maybe we # want a proper tree traversal with a lot of awareness of which diff --git a/Documentation/sphinx/kernel_feat.py b/Documentation/sphinx/kernel_feat.py new file mode 100644 index 000000000000..2fee04f1dedd --- /dev/null +++ b/Documentation/sphinx/kernel_feat.py @@ -0,0 +1,169 @@ +# coding=utf-8 +# SPDX-License-Identifier: GPL-2.0 +# +u""" + kernel-feat + ~~~~~~~~~~~ + + Implementation of the ``kernel-feat`` reST-directive. + + :copyright: Copyright (C) 2016 Markus Heiser + :copyright: Copyright (C) 2016-2019 Mauro Carvalho Chehab + :maintained-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> + :license: GPL Version 2, June 1991 see Linux/COPYING for details. + + The ``kernel-feat`` (:py:class:`KernelFeat`) directive calls the + scripts/get_feat.pl script to parse the Kernel ABI files. + + Overview of directive's argument and options. + + .. code-block:: rst + + .. kernel-feat:: <ABI directory location> + :debug: + + The argument ``<ABI directory location>`` is required. It contains the + location of the ABI files to be parsed. + + ``debug`` + Inserts a code-block with the *raw* reST. Sometimes it is helpful to see + what reST is generated. + +""" + +import codecs +import os +import subprocess +import sys + +from os import path + +from docutils import nodes, statemachine +from docutils.statemachine import ViewList +from docutils.parsers.rst import directives, Directive +from docutils.utils.error_reporting import ErrorString + +# +# AutodocReporter is only good up to Sphinx 1.7 +# +import sphinx + +Use_SSI = sphinx.__version__[:3] >= '1.7' +if Use_SSI: + from sphinx.util.docutils import switch_source_input +else: + from sphinx.ext.autodoc import AutodocReporter + +__version__ = '1.0' + +def setup(app): + + app.add_directive("kernel-feat", KernelFeat) + return dict( + version = __version__ + , parallel_read_safe = True + , parallel_write_safe = True + ) + +class KernelFeat(Directive): + + u"""KernelFeat (``kernel-feat``) directive""" + + required_arguments = 1 + optional_arguments = 2 + has_content = False + final_argument_whitespace = True + + option_spec = { + "debug" : directives.flag + } + + def warn(self, message, **replace): + replace["fname"] = self.state.document.current_source + replace["line_no"] = replace.get("line_no", self.lineno) + message = ("%(fname)s:%(line_no)s: [kernel-feat WARN] : " + message) % replace + self.state.document.settings.env.app.warn(message, prefix="") + + def run(self): + + doc = self.state.document + if not doc.settings.file_insertion_enabled: + raise self.warning("docutils: file insertion disabled") + + env = doc.settings.env + cwd = path.dirname(doc.current_source) + cmd = "get_feat.pl rest --dir " + cmd += self.arguments[0] + + if len(self.arguments) > 1: + cmd += " --arch " + self.arguments[1] + + srctree = path.abspath(os.environ["srctree"]) + + fname = cmd + + # extend PATH with $(srctree)/scripts + path_env = os.pathsep.join([ + srctree + os.sep + "scripts", + os.environ["PATH"] + ]) + shell_env = os.environ.copy() + shell_env["PATH"] = path_env + shell_env["srctree"] = srctree + + lines = self.runCmd(cmd, shell=True, cwd=cwd, env=shell_env) + nodeList = self.nestedParse(lines, fname) + return nodeList + + def runCmd(self, cmd, **kwargs): + u"""Run command ``cmd`` and return it's stdout as unicode.""" + + try: + proc = subprocess.Popen( + cmd + , stdout = subprocess.PIPE + , stderr = subprocess.PIPE + , **kwargs + ) + out, err = proc.communicate() + + out, err = codecs.decode(out, 'utf-8'), codecs.decode(err, 'utf-8') + + if proc.returncode != 0: + raise self.severe( + u"command '%s' failed with return code %d" + % (cmd, proc.returncode) + ) + except OSError as exc: + raise self.severe(u"problems with '%s' directive: %s." + % (self.name, ErrorString(exc))) + return out + + def nestedParse(self, lines, fname): + content = ViewList() + node = nodes.section() + + if "debug" in self.options: + code_block = "\n\n.. code-block:: rst\n :linenos:\n" + for l in lines.split("\n"): + code_block += "\n " + l + lines = code_block + "\n\n" + + for c, l in enumerate(lines.split("\n")): + content.append(l, fname, c) + + buf = self.state.memo.title_styles, self.state.memo.section_level, self.state.memo.reporter + + if Use_SSI: + with switch_source_input(self.state, content): + self.state.nested_parse(content, 0, node, match_titles=1) + else: + self.state.memo.title_styles = [] + self.state.memo.section_level = 0 + self.state.memo.reporter = AutodocReporter(content, self.state.memo.reporter) + try: + self.state.nested_parse(content, 0, node, match_titles=1) + finally: + self.state.memo.title_styles, self.state.memo.section_level, self.state.memo.reporter = buf + + return node.children diff --git a/Documentation/sphinx/requirements.txt b/Documentation/sphinx/requirements.txt index 489f6626de67..5030d346d23b 100644 --- a/Documentation/sphinx/requirements.txt +++ b/Documentation/sphinx/requirements.txt @@ -1,3 +1,4 @@ docutils Sphinx==2.4.4 sphinx_rtd_theme +six diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst index 2a5aa48eff6c..8ddb9b09451c 100644 --- a/Documentation/trace/events.rst +++ b/Documentation/trace/events.rst @@ -798,13 +798,13 @@ To trace a synthetic using the piecewise method described above, the synth_event_trace_start() function is used to 'open' the synthetic event trace:: - struct synth_trace_state trace_state; + struct synth_event_trace_state trace_state; ret = synth_event_trace_start(schedtest_event_file, &trace_state); It's passed the trace_event_file representing the synthetic event using the same methods as described above, along with a pointer to a -struct synth_trace_state object, which will be zeroed before use and +struct synth_event_trace_state object, which will be zeroed before use and used to maintain state between this and following calls. Once the event has been opened, which means space for it has been @@ -816,7 +816,7 @@ lookup per field. To assign the values one after the other without lookups, synth_event_add_next_val() should be used. Each call is passed the -same synth_trace_state object used in the synth_event_trace_start(), +same synth_event_trace_state object used in the synth_event_trace_start(), along with the value to set the next field in the event. After each field is set, the 'cursor' points to the next field, which will be set by the subsequent call, continuing until all the fields have been set @@ -845,7 +845,7 @@ this method would be (without error-handling code):: ret = synth_event_add_next_val(395, &trace_state); To assign the values in any order, synth_event_add_val() should be -used. Each call is passed the same synth_trace_state object used in +used. Each call is passed the same synth_event_trace_state object used in the synth_event_trace_start(), along with the field name of the field to set and the value to set it to. The same sequence of calls as in the above examples using this method would be (without error-handling @@ -867,7 +867,7 @@ can be used but not both at the same time. Finally, the event won't be actually traced until it's 'closed', which is done using synth_event_trace_end(), which takes only the -struct synth_trace_state object used in the previous calls:: +struct synth_event_trace_state object used in the previous calls:: ret = synth_event_trace_end(&trace_state); diff --git a/Documentation/translations/it_IT/doc-guide/kernel-doc.rst b/Documentation/translations/it_IT/doc-guide/kernel-doc.rst index 524ad86cadbb..009cdac014b6 100644 --- a/Documentation/translations/it_IT/doc-guide/kernel-doc.rst +++ b/Documentation/translations/it_IT/doc-guide/kernel-doc.rst @@ -419,26 +419,24 @@ del `dominio Sphinx per il C`_. Riferimenti usando reStructuredText ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Per fare riferimento a funzioni e tipi di dato definiti nei commenti kernel-doc -all'interno dei documenti reStructuredText, utilizzate i riferimenti dal -`dominio Sphinx per il C`_. Per esempio:: +Nei documenti reStructuredText non serve alcuna sintassi speciale per +fare riferimento a funzioni e tipi definiti nei commenti +kernel-doc. Sarà sufficiente terminare i nomi di funzione con ``()``, +e scrivere ``struct``, ``union``, ``enum``, o ``typedef`` prima di un +tipo. Per esempio:: - See function :c:func:`foo` and struct/union/enum/typedef :c:type:`bar`. + See foo() + See struct foo. + See union bar. + See enum baz. + See typedef meh. -Nonostante il riferimento ai tipi di dato funzioni col solo nome, -ovvero senza specificare struct/union/enum/typedef, potreste preferire il -seguente:: +Tuttavia, la personalizzazione dei collegamenti è possibile solo con +la seguente sintassi:: - See :c:type:`struct foo <foo>`. - See :c:type:`union bar <bar>`. - See :c:type:`enum baz <baz>`. - See :c:type:`typedef meh <meh>`. + See :c:func:`my custom link text for function foo <foo>`. + See :c:type:`my custom link text for struct bar <bar>`. -Questo produce dei collegamenti migliori, ed è in linea con il modo in cui -kernel-doc gestisce i riferimenti. - -Per maggiori informazioni, siete pregati di consultare la documentazione -del `dominio Sphinx per il C`_. Commenti per una documentazione generale ---------------------------------------- diff --git a/Documentation/translations/it_IT/doc-guide/sphinx.rst b/Documentation/translations/it_IT/doc-guide/sphinx.rst index f1ad4504b734..090d2949d345 100644 --- a/Documentation/translations/it_IT/doc-guide/sphinx.rst +++ b/Documentation/translations/it_IT/doc-guide/sphinx.rst @@ -364,6 +364,26 @@ Che verrà rappresentata nel seguente modo: - column 3 +Riferimenti incrociati +---------------------- + +Per fare dei riferimenti incrociati da una pagina ad un'altra +specificando il percorso a partire dalla cartella *Documentation*. +Per esempio, se volete aggiungere un riferimento a questa pagina +(l'estensione .rst è opzionale):: + + See Documentation/translations/it_IT/doc-guide/sphinx.rst. + +Se preferite usare un percorso relative allora vi serve la direttiva +Sphinx ``doc``. Per esempio, se volete aggiungere un riferimento a +questa pagina dalla stessa cartella:: + + See :doc:`sphinx`. + +Per maggiori informazioni su come aggiungere riferimenti incrociati a +commenti kernel-doc di funzioni o tipi, leggete +Documentation/translations/it_IT/doc-guide/sphinx.rst. + .. _it_sphinx_kfigure: Figure ed immagini diff --git a/Documentation/translations/it_IT/process/2.Process.rst b/Documentation/translations/it_IT/process/2.Process.rst index 30dc172f06b0..62826034e0b2 100644 --- a/Documentation/translations/it_IT/process/2.Process.rst +++ b/Documentation/translations/it_IT/process/2.Process.rst @@ -123,7 +123,7 @@ iniziale, i kernel ricevono aggiornamenti per più di un ciclo di sviluppo. Quindi, per esempio, la storia del kernel 5.2 appare così (anno 2019): ============== =============================== - 15 settembre 5.2 rilascio stabile FIXME settembre è sbagliato + 7 luglio 5.2 rilascio stabile 14 luglio 5.2.1 21 luglio 5.2.2 26 luglio 5.2.3 @@ -434,7 +434,7 @@ l'elenco principale lo si trova sul sito: http://vger.kernel.org/vger-lists.html Esistono liste gestite altrove; un certo numero di queste sono in -lists.redhat.com. +redhat.com/mailman/listinfo. La lista di discussione principale per lo sviluppo del kernel è, ovviamente, linux-kernel. Questa lista è un luogo ostile dove trovarsi; i volumi possono diff --git a/Documentation/translations/it_IT/process/changes.rst b/Documentation/translations/it_IT/process/changes.rst index 37da4447a40d..cc883f8d96c4 100644 --- a/Documentation/translations/it_IT/process/changes.rst +++ b/Documentation/translations/it_IT/process/changes.rst @@ -32,9 +32,10 @@ PC Card, per esempio, probabilmente non dovreste preoccuparvi di pcmciautils. ====================== ================= ======================================== Programma Versione minima Comando per verificare la versione ====================== ================= ======================================== -GNU C 4.6 gcc --version +GNU C 4.9 gcc --version +Clang/LLVM (optional) 10.0.1 clang --version GNU make 3.81 make --version -binutils 2.21 ld -v +binutils 2.23 ld -v flex 2.5.35 flex --version bison 2.0 bison --version util-linux 2.10o fdformat --version @@ -71,6 +72,16 @@ GCC La versione necessaria di gcc potrebbe variare a seconda del tipo di CPU nel vostro calcolatore. +Clang/LLVM (opzionale) +---------------------- + +L'ultima versione di clang e *LLVM utils* (secondo `releases.llvm.org +<https://releases.llvm.org>`_) sono supportati per la generazione del +kernel. Non garantiamo che anche i rilasci più vecchi funzionino, inoltre +potremmo rimuovere gli espedienti che abbiamo implementato per farli +funzionare. Per maggiori informazioni +:ref:`Building Linux with Clang/LLVM <kbuild_llvm>`. + Make ---- @@ -79,7 +90,7 @@ Per compilare il kernel vi servirà GNU make 3.81 o successivo. Binutils -------- -Per generare il kernel è necessario avere Binutils 2.21 o superiore. +Per generare il kernel è necessario avere Binutils 2.23 o superiore. pkg-config ---------- @@ -338,6 +349,11 @@ gcc - <ftp://ftp.gnu.org/gnu/gcc/> +Clang/LLVM +---------- + +- :ref:`Getting LLVM <getting_llvm>`. + Make ---- diff --git a/Documentation/translations/it_IT/process/coding-style.rst b/Documentation/translations/it_IT/process/coding-style.rst index a346f1f2ce21..c86c4543f249 100644 --- a/Documentation/translations/it_IT/process/coding-style.rst +++ b/Documentation/translations/it_IT/process/coding-style.rst @@ -92,16 +92,22 @@ delle righe. Lo stile del codice riguarda la leggibilità e la manutenibilità utilizzando strumenti comuni. -Il limite delle righe è di 80 colonne e questo e un limite fortemente -desiderato. - -Espressioni più lunghe di 80 colonne saranno spezzettate in pezzi più piccoli, -a meno che eccedere le 80 colonne non aiuti ad aumentare la leggibilità senza -nascondere informazioni. I pezzi derivati sono sostanzialmente più corti degli -originali e vengono posizionati più a destra. Lo stesso si applica, nei file -d'intestazione, alle funzioni con una lista di argomenti molto lunga. Tuttavia, -non spezzettate mai le stringhe visibili agli utenti come i messaggi di -printk, questo perché inibireste la possibilità d'utilizzare grep per cercarle. +Come limite di riga si preferiscono le 80 colonne. + +Espressioni più lunghe di 80 colonne dovrebbero essere spezzettate in +pezzi più piccoli, a meno che eccedere le 80 colonne non aiuti ad +aumentare la leggibilità senza nascondere informazioni. + +I nuovi pezzi derivati sono sostanzialmente più corti degli originali +e vengono posizionati più a destra. Uno stile molto comune è quello di +allineare i nuovi pezzi alla parentesi aperta di una funzione. + +Lo stesso si applica, nei file d'intestazione, alle funzioni con una +lista di argomenti molto lunga. + +Tuttavia, non spezzettate mai le stringhe visibili agli utenti come i +messaggi di printk, questo perché inibireste la possibilità +d'utilizzare grep per cercarle. 3) Posizionamento di parentesi graffe e spazi --------------------------------------------- diff --git a/Documentation/translations/it_IT/process/deprecated.rst b/Documentation/translations/it_IT/process/deprecated.rst index a642ff3fdc8b..07c79d4bafca 100644 --- a/Documentation/translations/it_IT/process/deprecated.rst +++ b/Documentation/translations/it_IT/process/deprecated.rst @@ -95,6 +95,11 @@ Invece, usate la seguente funzione:: header = kzalloc(struct_size(header, item, count), GFP_KERNEL); +.. note:: Se per caso state usando struct_size() su una struttura dati che + in coda contiene un array di lunghezza zero o uno, allora siete + invitati a riorganizzare il vostro codice usando il + `flexible array member <#zero-length-and-one-element-arrays>`_. + Per maggiori dettagli fate riferimento a array_size(), array3_size(), e struct_size(), così come la famiglia di funzioni check_add_overflow() e check_mul_overflow(). @@ -116,7 +121,11 @@ di destinazione. Questo può portare ad un overflow oltre i limiti del buffer e generare svariati tipi di malfunzionamenti. Nonostante l'opzione `CONFIG_FORTIFY_SOURCE=y` e svariate opzioni del compilatore aiutano a ridurne il rischio, non c'è alcuna buona ragione per continuare ad usare -questa funzione. La versione sicura da usare è strscpy(). +questa funzione. La versione sicura da usare è strscpy(), tuttavia va +prestata attenzione a tutti quei casi dove viene usato il valore di +ritorno di strcpy(). La funzione strscpy() non ritorna un puntatore +alla destinazione, ma un contatore dei byte non NUL copiati (oppure +un errno negativo se la stringa è stata troncata). strncpy() su stringe terminate con NUL -------------------------------------- @@ -127,8 +136,12 @@ causati, appunto, dalla mancanza del terminatore. Questa estende la terminazione nel buffer di destinazione quando la stringa d'origine è più corta; questo potrebbe portare ad una penalizzazione delle prestazioni per chi usa solo stringe terminate. La versione sicura da usare è -strscpy(). (chi usa strscpy() e necessita di estendere la -terminazione con NUL deve aggiungere una chiamata a memset()) +strscpy(), tuttavia va prestata attenzione a tutti quei casi dove +viene usato il valore di ritorno di strncpy(). La funzione strscpy() +non ritorna un puntatore alla destinazione, ma un contatore dei byte +non NUL copiati (oppure un errno negativo se la stringa è stata +troncata). Tutti i casi che necessitano di estendere la +terminazione con NUL dovrebbero usare strscpy_pad(). Se il chiamate no usa stringhe terminate con NUL, allore strncpy() può continuare ad essere usata, ma i buffer di destinazione devono essere @@ -140,7 +153,10 @@ strlcpy() La funzione strlcpy(), per prima cosa, legge interamente il buffer di origine, magari leggendo più di quanto verrà effettivamente copiato. Questo è inefficiente e può portare a overflow di lettura quando la stringa non è -terminata con NUL. La versione sicura da usare è strscpy(). +terminata con NUL. La versione sicura da usare è strscpy(), tuttavia +va prestata attenzione a tutti quei casi dove viene usato il valore di +ritorno di strlcpy(), dato che strscpy() ritorna un valore di errno +negativo quanto la stringa viene troncata. Segnaposto %p nella stringa di formato -------------------------------------- @@ -227,3 +243,126 @@ modi: * ``continue;`` * ``goto <label>;`` * ``return [expression];`` + +Array di lunghezza zero o con un solo elemento +---------------------------------------------- +All'interno del kernel ricorre spesso la necessita di avere membri +di dimensione variabile all'interno di una struttura dati. In questi +casi il codice del kernel dovrebbe usare sempre i `"flexible array +member" <https://en.wikipedia.org/wiki/Flexible_array_member>`_. La +tecnica degli array a lunghezza nulla o di un solo elemento non +dovrebbe essere più usata. + +Nel codice C più vecchio, la dichiarazione di un membro di dimensione +variabile in coda ad una struttura dati veniva fatto dichiarando un +array di un solo elemento posizionato alla fine della struttura dati:: + + struct something { + size_t count; + struct foo items[1]; + }; + +Questo ha portato ad un calcolo di sizeof() traballante (dovrebbe +rimuovere la dimensione del singolo elemento in coda per calcolare la +dimensione esatta dell' "intestazione"). Per evitare questi problemi è +stata introdotta un' `estensione a GNU C +<https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html>`_ che +permettesse la dichiarazione di array a lungezza zero:: + + struct something { + size_t count; + struct foo items[0]; + }; + +Ma questo ha portato nuovi problemi, e non ha risolto alcuni dei +problemi che affliggono entrambe le tecniche: per esempio +l'impossibilità di riconoscere se un array di quel tipo viene usato +nel mezzo di una struttura dati e _non_ alla fine (potrebbe accadere +sia direttamente, sia indirettamente quando si usano le unioni o le +strutture di strutture). + +Lo standard C99 introduce i "flexible array members". Questi array non +hanno una dimensione nella loro dichiarazione:: + + struct something { + size_t count; + struct foo items[]; + }; + +Questo è il modo con cui ci si aspetta che vengano dichiarati gli +elementi di lunghezza variabile in coda alle strutture dati. Permette +al compilatore di produrre errori quando gli array flessibili non si +trovano alla fine della struttura dati, il che permette di prevenire +alcuni tipi di bachi dovuti a `comportamenti inaspettati +<https://git.kernel.org/linus/76497732932f15e7323dc805e8ea8dc11bb587cf>`_. +Inoltre, permette al compilatore di analizzare correttamente le +dimensioni degli array (attraverso sizeof(), `CONFIG_FORTIFY_SOURCE`, +e `CONFIG_UBSAN_BOUNDS`). Per esempio, non esiste alcun meccanismo in +grado di avvisarci che il seguente uso di sizeof() dia sempre come +zero come risultato:: + + struct something { + size_t count; + struct foo items[0]; + }; + + struct something *instance; + + instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL); + instance->count = count; + + size = sizeof(instance->items) * instance->count; + memcpy(instance->items, source, size); + +Il valore di ``size`` nell'ultima riga sarà ``zero``, quando uno +invece si aspetterebbe che il suo valore sia la dimensione totale in +byte dell'allocazione dynamica che abbiamo appena fatto per l'array +``items``. Qui un paio di esempi reali del problema: `collegamento 1 +<https://git.kernel.org/linus/f2cd32a443da694ac4e28fbf4ac6f9d5cc63a539>`_, +`collegamento 2 +<https://git.kernel.org/linus/ab91c2a89f86be2898cee208d492816ec238b2cf>`_. +Invece, `i flexible array members hanno un tipo incompleto, e quindi +sizeof() non può essere applicato +<https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html>`_; dunque ogni +uso scorretto di questo operatore verrà identificato immediatamente +durante la compilazione. + +Per quanto riguarda gli array di un solo elemento, bisogna essere +consapevoli che `questi array occupano almeno quanto lo spazio di un +singolo oggetti dello stesso tipo +<https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html>`_, e quindi +contribuiscono al calcolo della dimensione della struttura che li +contiene. In questo caso è facile commettere errori quando si vuole +calcolare la dimensione totale della memoria totale da allocare per +una struttura dati:: + + struct something { + size_t count; + struct foo items[1]; + }; + + struct something *instance; + + instance = kmalloc(struct_size(instance, items, count - 1), GFP_KERNEL); + instance->count = count; + + size = sizeof(instance->items) * instance->count; + memcpy(instance->items, source, size); + +In questo esempio ci siamo dovuti ricordare di usare ``count - 1`` in +struct_size(), altrimenti avremmo --inavvertitamente-- allocato +memoria per un oggetti ``items`` in più. Il modo più pulito e meno +propenso agli errori è quello di usare i `flexible array member`, in +combinazione con struct_size() e flex_array_size():: + + struct something { + size_t count; + struct foo items[]; + }; + + struct something *instance; + + instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL); + instance->count = count; + + memcpy(instance->items, source, flex_array_size(instance, items, instance->count)); diff --git a/Documentation/translations/it_IT/process/email-clients.rst b/Documentation/translations/it_IT/process/email-clients.rst index 66d3d65776f7..de7d32f78246 100644 --- a/Documentation/translations/it_IT/process/email-clients.rst +++ b/Documentation/translations/it_IT/process/email-clients.rst @@ -32,6 +32,11 @@ impostato come ``text/plain``. Tuttavia, generalmente gli allegati non sono ben apprezzati perché rende più difficile citare porzioni di patch durante il processo di revisione. +Inoltre, è vivamente raccomandato l'uso di puro testo nel corpo del +messaggio, sia per la patch che per qualsiasi altro messaggio. Il sito +https://useplaintext.email/ può esservi d'aiuto per configurare il +vostro programma di posta elettronica. + I programmi di posta elettronica che vengono usati per inviare le patch per il kernel Linux dovrebbero inviarle senza alterazioni. Per esempio, non dovrebbero modificare o rimuovere tabulazioni o spazi, nemmeno all'inizio o diff --git a/Documentation/translations/it_IT/process/programming-language.rst b/Documentation/translations/it_IT/process/programming-language.rst index c4fc9d394c29..41db2598ce11 100644 --- a/Documentation/translations/it_IT/process/programming-language.rst +++ b/Documentation/translations/it_IT/process/programming-language.rst @@ -11,13 +11,15 @@ Linguaggio di programmazione Il kernel è scritto nel linguaggio di programmazione C [it-c-language]_. Più precisamente, il kernel viene compilato con ``gcc`` [it-gcc]_ usando l'opzione ``-std=gnu89`` [it-gcc-c-dialect-options]_: il dialetto GNU -dello standard ISO C90 (con l'aggiunta di alcune funzionalità da C99) +dello standard ISO C90 (con l'aggiunta di alcune funzionalità da C99). +Linux supporta anche ``clang`` [it-clang]_, leggete la documentazione +:ref:`Building Linux with Clang/LLVM <kbuild_llvm>`. Questo dialetto contiene diverse estensioni al linguaggio [it-gnu-extensions]_, e molte di queste vengono usate sistematicamente dal kernel. -Il kernel offre un certo livello di supporto per la compilazione con ``clang`` -[it-clang]_ e ``icc`` [it-icc]_ su diverse architetture, tuttavia in questo momento +Il kernel offre un certo livello di supporto per la compilazione con +``icc`` [it-icc]_ su diverse architetture, tuttavia in questo momento il supporto non è completo e richiede delle patch aggiuntive. Attributi diff --git a/Documentation/translations/it_IT/process/submitting-patches.rst b/Documentation/translations/it_IT/process/submitting-patches.rst index 7c23c08e4401..966cd3242a60 100644 --- a/Documentation/translations/it_IT/process/submitting-patches.rst +++ b/Documentation/translations/it_IT/process/submitting-patches.rst @@ -16,21 +16,19 @@ vostre patch accettate. Questo documento contiene un vasto numero di suggerimenti concisi. Per maggiori dettagli su come funziona il processo di sviluppo del kernel leggete -:ref:`Documentation/translations/it_IT/process <it_development_process_main>`. -Leggete anche :ref:`Documentation/translations/it_IT/process/submit-checklist.rst <it_submitchecklist>` -per una lista di punti da verificare prima di inviare del codice. Se state -inviando un driver, allora leggete anche :ref:`Documentation/translations/it_IT/process/submitting-drivers.rst <it_submittingdrivers>`; -per delle patch relative alle associazioni per Device Tree leggete -Documentation/devicetree/bindings/submitting-patches.rst. - -Molti di questi passi descrivono il comportamento di base del sistema di -controllo di versione ``git``; se utilizzate ``git`` per preparare le vostre -patch molto del lavoro più ripetitivo lo troverete già fatto per voi, tuttavia -dovete preparare e documentare un certo numero di patch. Generalmente, l'uso -di ``git`` renderà la vostra vita di sviluppatore del kernel più facile. - -0) Ottenere i sorgenti attuali ------------------------------- +:doc:`development-process`. +Leggete anche :doc:`submit-checklist` per una lista di punti da +verificare prima di inviare del codice. Se state inviando un driver, +allora leggete anche :doc:`submitting-drivers`; per delle patch +relative alle associazioni per Device Tree leggete +:doc:`submitting-patches`. + +Questa documentazione assume che sappiate usare ``git`` per preparare le patch. +Se non siete pratici di ``git``, allora è bene che lo impariate; +renderà la vostra vita di sviluppatore del kernel molto più semplice. + +Ottenere i sorgenti attuali +--------------------------- Se non avete un repositorio coi sorgenti del kernel più recenti, allora usate ``git`` per ottenerli. Vorrete iniziare col repositorio principale che può @@ -45,69 +43,10 @@ Guardate l'elemento **T:** per un determinato sottosistema nel file MAINTANERS che troverete nei sorgenti, o semplicemente chiedete al manutentore nel caso in cui i sorgenti da usare non siano elencati il quel file. -Esiste ancora la possibilità di scaricare un rilascio del kernel come archivio -tar (come descritto in una delle prossime sezioni), ma questa è la via più -complicata per sviluppare per il kernel. - -1) ``diff -up`` ---------------- - -Se dovete produrre le vostre patch a mano, usate ``diff -up`` o ``diff -uprN`` -per crearle. Git produce di base le patch in questo formato; se state -usando ``git``, potete saltare interamente questa sezione. - -Tutte le modifiche al kernel Linux avvengono mediate patch, come descritte -in :manpage:`diff(1)`. Quando create la vostra patch, assicuratevi di -crearla nel formato "unified diff", come l'argomento ``-u`` di -:manpage:`diff(1)`. -Inoltre, per favore usate l'argomento ``-p`` per mostrare la funzione C -alla quale si riferiscono le diverse modifiche - questo rende il risultato -di ``diff`` molto più facile da leggere. Le patch dovrebbero essere basate -sulla radice dei sorgenti del kernel, e non sulle sue sottocartelle. - -Per creare una patch per un singolo file, spesso è sufficiente fare:: - - SRCTREE=linux - MYFILE=drivers/net/mydriver.c - - cd $SRCTREE - cp $MYFILE $MYFILE.orig - vi $MYFILE # make your change - cd .. - diff -up $SRCTREE/$MYFILE{.orig,} > /tmp/patch - -Per creare una patch per molteplici file, dovreste spacchettare i sorgenti -"vergini", o comunque non modificati, e fare un ``diff`` coi vostri. -Per esempio:: - - MYSRC=/devel/linux - - tar xvfz linux-3.19.tar.gz - mv linux-3.19 linux-3.19-vanilla - diff -uprN -X linux-3.19-vanilla/Documentation/dontdiff \ - linux-3.19-vanilla $MYSRC > /tmp/patch - -``dontdiff`` è una lista di file che sono generati durante il processo di -compilazione del kernel; questi dovrebbero essere ignorati in qualsiasi -patch generata con :manpage:`diff(1)`. - -Assicuratevi che la vostra patch non includa file che non ne fanno veramente -parte. Al fine di verificarne la correttezza, assicuratevi anche di -revisionare la vostra patch -dopo- averla generata con :manpage:`diff(1)`. - -Se le vostre modifiche producono molte differenze, allora dovrete dividerle -in patch indipendenti che modificano le cose in passi logici; leggete -:ref:`split_changes`. Questo faciliterà la revisione da parte degli altri -sviluppatori, il che è molto importante se volete che la patch venga accettata. - -Se state utilizzando ``git``, ``git rebase -i`` può aiutarvi nel procedimento. -Se non usate ``git``, un'alternativa popolare è ``quilt`` -<http://savannah.nongnu.org/projects/quilt>. - .. _it_describe_changes: -2) Descrivete le vostre modifiche ---------------------------------- +Descrivete le vostre modifiche +------------------------------ Descrivete il vostro problema. Esiste sempre un problema che via ha spinto ha fare il vostro lavoro, che sia la correzione di un baco da una riga o una @@ -208,10 +147,15 @@ precedente:: [pretty] fixes = Fixes: %h (\"%s\") +Un esempio:: + + $ git log -1 --pretty=fixes 54a4f0239f2e + Fixes: 54a4f0239f2e ("KVM: MMU: make kvm_mmu_zap_page() return the number of pages it actually freed") + .. _it_split_changes: -3) Separate le vostre modifiche -------------------------------- +Separate le vostre modifiche +---------------------------- Separate ogni **cambiamento logico** in patch distinte. @@ -312,7 +256,8 @@ sfruttato, inviatela a security@kernel.org. Per bachi importanti, un breve embargo potrebbe essere preso in considerazione per dare il tempo alle distribuzioni di prendere la patch e renderla disponibile ai loro utenti; in questo caso, ovviamente, la patch non dovrebbe essere inviata su alcuna -lista di discussione pubblica. +lista di discussione pubblica. Leggete anche +:doc:`/admin-guide/security-bugs`. Patch che correggono bachi importanti su un kernel già rilasciato, dovrebbero essere inviate ai manutentori dei kernel stabili aggiungendo la seguente riga:: @@ -354,8 +299,8 @@ Le patch banali devono rientrare in una delle seguenti categorie: "patch monkey" in modalità ritrasmissione) -6) Niente: MIME, links, compressione, allegati. Solo puro testo ----------------------------------------------------------------- +Niente: MIME, links, compressione, allegati. Solo puro testo +------------------------------------------------------------- Linus e gli altri sviluppatori del kernel devono poter commentare le modifiche che sottomettete. Per uno sviluppatore è importante @@ -364,7 +309,11 @@ programmi di posta elettronica, cosicché sia possibile commentare una porzione specifica del vostro codice. Per questa ragione tutte le patch devono essere inviate via e-mail -come testo. +come testo. Il modo più facile, e quello raccomandato, è con ``git +send-email``. Al sito https://git-send-email.io è disponibile una +guida interattiva sull'uso di ``git send-email``. + +Se decidete di non usare ``git send-email``: .. warning:: @@ -381,28 +330,20 @@ così la possibilità che il vostro allegato-MIME venga accettato. Eccezione: se il vostro servizio di posta storpia le patch, allora qualcuno potrebbe chiedervi di rinviarle come allegato MIME. -Leggete :ref:`Documentation/translations/it_IT/process/email-clients.rst <it_email_clients>` +Leggete :doc:`/translations/it_IT/process/email-clients` per dei suggerimenti sulla configurazione del programmi di posta elettronica per l'invio di patch intatte. -7) Dimensione delle e-mail --------------------------- - -Le grosse modifiche non sono adatte ad una lista di discussione, e nemmeno -per alcuni manutentori. Se la vostra patch, non compressa, eccede i 300 kB -di spazio, allora caricatela in una spazio accessibile su internet fornendo -l'URL (collegamento) ad essa. Ma notate che se la vostra patch eccede i 300 kB -è quasi certo che necessiti comunque di essere spezzettata. - -8) Rispondere ai commenti di revisione --------------------------------------- +Rispondere ai commenti di revisione +----------------------------------- -Quasi certamente i revisori vi invieranno dei commenti su come migliorare -la vostra patch. Dovete rispondere a questi commenti; ignorare i revisori -è un ottimo modo per essere ignorati. Riscontri o domande che non conducono -ad una modifica del codice quasi certamente dovrebbero portare ad un commento -nel changelog cosicché il prossimo revisore potrà meglio comprendere cosa stia -accadendo. +In risposta alla vostra email, quasi certamente i revisori vi +invieranno dei commenti su come migliorare la vostra patch. Dovete +rispondere a questi commenti; ignorare i revisori è un ottimo modo per +essere ignorati. Riscontri o domande che non conducono ad una +modifica del codice quasi certamente dovrebbero portare ad un commento +nel changelog cosicché il prossimo revisore potrà meglio comprendere +cosa stia accadendo. Assicuratevi di dire ai revisori quali cambiamenti state facendo e di ringraziarli per il loro tempo. Revisionare codice è un lavoro faticoso e che @@ -410,8 +351,12 @@ richiede molto tempo, e a volte i revisori diventano burberi. Tuttavia, anche in questo caso, rispondete con educazione e concentratevi sul problema che hanno evidenziato. -9) Non scoraggiatevi - o impazientitevi ---------------------------------------- +Leggete :doc:`/translations/it_IT/process/email-clients` per +le raccomandazioni sui programmi di posta elettronica e l'etichetta da usare +sulle liste di discussione. + +Non scoraggiatevi - o impazientitevi +------------------------------------ Dopo che avete inviato le vostre modifiche, siate pazienti e aspettate. I revisori sono persone occupate e potrebbero non ricevere la vostra patch @@ -424,17 +369,19 @@ aver inviato le patch correttamente. Aspettate almeno una settimana prima di rinviare le modifiche o sollecitare i revisori - probabilmente anche di più durante la finestra d'integrazione. -10) Aggiungete PATCH nell'oggetto ---------------------------------- +Aggiungete PATCH nell'oggetto +----------------------------- Dato l'alto volume di e-mail per Linus, e la lista linux-kernel, è prassi prefiggere il vostro oggetto con [PATCH]. Questo permette a Linus e agli altri sviluppatori del kernel di distinguere facilmente le patch dalle altre discussioni. +``git send-email`` lo fa automaticamente. -11) Firmate il vostro lavoro - Il certificato d'origine dello sviluppatore --------------------------------------------------------------------------- + +Firmate il vostro lavoro - Il certificato d'origine dello sviluppatore +---------------------------------------------------------------------- Per migliorare la tracciabilità su "chi ha fatto cosa", specialmente per quelle patch che per raggiungere lo stadio finale passano attraverso @@ -477,65 +424,17 @@ poi dovete solo aggiungere una riga che dice:: Signed-off-by: Random J Developer <random@developer.example.org> usando il vostro vero nome (spiacenti, non si accettano pseudonimi o -contributi anonimi). +contributi anonimi). Questo verrà fatto automaticamente se usate +``git commit -s``. Anche il ripristino di uno stato precedente dovrebbe +includere "Signed-off-by", se usate ``git revert -s`` questo verrà +fatto automaticamente. Alcune persone aggiungono delle etichette alla fine. Per ora queste verranno ignorate, ma potete farlo per meglio identificare procedure aziendali interne o per aggiungere dettagli circa la firma. -Se siete un manutentore di un sottosistema o di un ramo, qualche volta dovrete -modificare leggermente le patch che avete ricevuto al fine di poterle -integrare; questo perché il codice non è esattamente lo stesso nei vostri -sorgenti e in quelli dei vostri contributori. Se rispettate rigidamente la -regola (c), dovreste chiedere al mittente di rifare la patch, ma questo è -controproducente e una totale perdita di tempo ed energia. La regola (b) -vi permette di correggere il codice, ma poi diventa davvero maleducato cambiare -la patch di qualcuno e addossargli la responsabilità per i vostri bachi. -Per risolvere questo problema dovreste aggiungere una riga, fra l'ultimo -Signed-off-by e il vostro, che spiega la vostra modifica. Nonostante non ci -sia nulla di obbligatorio, un modo efficace è quello di indicare il vostro -nome o indirizzo email fra parentesi quadre, seguito da una breve descrizione; -questo renderà abbastanza visibile chi è responsabile per le modifiche -dell'ultimo minuto. Per esempio:: - - Signed-off-by: Random J Developer <random@developer.example.org> - [lucky@maintainer.example.org: struct foo moved from foo.c to foo.h] - Signed-off-by: Lucky K Maintainer <lucky@maintainer.example.org> - -Questa pratica è particolarmente utile se siete i manutentori di un ramo -stabile ma al contempo volete dare credito agli autori, tracciare e integrare -le modifiche, e proteggere i mittenti dalle lamentele. Notate che in nessuna -circostanza è permessa la modifica dell'identità dell'autore (l'intestazione -From), dato che è quella che appare nei changelog. - -Un appunto speciale per chi porta il codice su vecchie versioni. Sembra che -sia comune l'utile pratica di inserire un'indicazione circa l'origine della -patch all'inizio del messaggio di commit (appena dopo la riga dell'oggetto) -al fine di migliorare la tracciabilità. Per esempio, questo è quello che si -vede nel rilascio stabile 3.x-stable:: - - Date: Tue Oct 7 07:26:38 2014 -0400 - - libata: Un-break ATA blacklist - - commit 1c40279960bcd7d52dbdf1d466b20d24b99176c8 upstream. - -E qui quello che potrebbe vedersi su un kernel più vecchio dove la patch è -stata applicata:: - - Date: Tue May 13 22:12:27 2008 +0200 - - wireless, airo: waitbusy() won't delay - - [backport of 2.6 commit b7acbdfbd1f277c1eb23f344f899cfa4cd0bf36a] - -Qualunque sia il formato, questa informazione fornisce un importante aiuto -alle persone che vogliono seguire i vostri sorgenti, e quelle che cercano -dei bachi. - - -12) Quando utilizzare Acked-by:, Cc:, e Co-developed-by: --------------------------------------------------------- +Quando utilizzare Acked-by:, Cc:, e Co-developed-by: +---------------------------------------------------- L'etichetta Signed-off-by: indica che il firmatario è stato coinvolto nello sviluppo della patch, o che era nel suo percorso di consegna. @@ -604,8 +503,8 @@ Esempio di una patch sottomessa dall'autore Co-developed-by::: Co-developed-by: Submitting Co-Author <sub@coauthor.example.org> Signed-off-by: Submitting Co-Author <sub@coauthor.example.org> -13) Utilizzare Reported-by:, Tested-by:, Reviewed-by:, Suggested-by: e Fixes: ------------------------------------------------------------------------------ +Utilizzare Reported-by:, Tested-by:, Reviewed-by:, Suggested-by: e Fixes: +------------------------------------------------------------------------- L'etichetta Reported-by da credito alle persone che trovano e riportano i bachi e si spera che questo possa ispirarli ad aiutarci nuovamente in futuro. @@ -654,6 +553,13 @@ revisori conosciuti per la loro conoscenza sulla materia in oggetto e per la loro serietà nella revisione, accrescerà le probabilità che la vostra patch venga integrate nel kernel. +Quando si riceve una email sulla lista di discussione da un tester o +un revisore, le etichette Tested-by o Reviewd-by devono essere +aggiunte dall'autore quando invierà nuovamente la patch. Tuttavia, se +la patch è cambiata in modo significativo, queste etichette potrebbero +non avere più senso e quindi andrebbero rimosse. Solitamente si tiene traccia +della rimozione nel changelog della patch (subito dopo il separatore '---'). + L'etichetta Suggested-by: indica che l'idea della patch è stata suggerita dalla persona nominata e le da credito. Tenete a mente che questa etichetta non dovrebbe essere aggiunta senza un permesso esplicito, specialmente se @@ -669,8 +575,8 @@ Questo è il modo suggerito per indicare che un baco è stato corretto nella patch. Per maggiori dettagli leggete :ref:`it_describe_changes` -14) Il formato canonico delle patch ------------------------------------ +Il formato canonico delle patch +------------------------------- Questa sezione descrive il formato che dovrebbe essere usato per le patch. Notate che se state usando un repositorio ``git`` per salvare le vostre patch @@ -788,8 +694,8 @@ Maggiori dettagli sul formato delle patch nei riferimenti qui di seguito. .. _it_explicit_in_reply_to: -15) Usare esplicitamente In-Reply-To nell'intestazione ------------------------------------------------------- +Usare esplicitamente In-Reply-To nell'intestazione +-------------------------------------------------- Aggiungere manualmente In-Reply-To: nell'intestazione dell'e-mail potrebbe essere d'aiuto per associare una patch ad una discussione @@ -802,65 +708,6 @@ giungla di riferimenti all'interno dei programmi di posta. Se un collegamento ad una versione precedente di una serie di patch (per esempio, potete usarlo per l'email introduttiva alla serie). -16) Inviare richieste ``git pull`` ----------------------------------- - -Se avete una serie di patch, potrebbe essere più conveniente per un manutentore -tirarle dentro al repositorio del sottosistema attraverso l'operazione -``git pull``. Comunque, tenete presente che prendere patch da uno sviluppatore -in questo modo richiede un livello di fiducia più alto rispetto a prenderle da -una lista di discussione. Di conseguenza, molti manutentori sono riluttanti -ad accettare richieste di *pull*, specialmente dagli sviluppatori nuovi e -quindi sconosciuti. Se siete in dubbio, potete fare una richiesta di *pull* -come messaggio introduttivo ad una normale pubblicazione di patch, così -il manutentore avrà la possibilità di scegliere come integrarle. - -Una richiesta di *pull* dovrebbe avere nell'oggetto [GIT] o [PULL]. -La richiesta stessa dovrebbe includere il nome del repositorio e quello del -ramo su una singola riga; dovrebbe essere più o meno così:: - - Please pull from - - git://jdelvare.pck.nerim.net/jdelvare-2.6 i2c-for-linus - - to get these changes: - -Una richiesta di *pull* dovrebbe includere anche un messaggio generico -che dica cos'è incluso, una lista delle patch usando ``git shortlog``, e una -panoramica sugli effetti della serie di patch con ``diffstat``. Il modo più -semplice per ottenere tutte queste informazioni è, ovviamente, quello di -lasciar fare tutto a ``git`` con il comando ``git request-pull``. - -Alcuni manutentori (incluso Linus) vogliono vedere le richieste di *pull* -da commit firmati con GPG; questo fornisce una maggiore garanzia sul fatto -che siate stati proprio voi a fare la richiesta. In assenza di tale etichetta -firmata Linus, in particolare, non prenderà alcuna patch da siti pubblici come -GitHub. - -Il primo passo verso la creazione di questa etichetta firmata è quello di -creare una chiave GNUPG ed averla fatta firmare da uno o più sviluppatori -principali del kernel. Questo potrebbe essere difficile per i nuovi -sviluppatori, ma non ci sono altre vie. Andare alle conferenze potrebbe -essere un buon modo per trovare sviluppatori che possano firmare la vostra -chiave. - -Una volta che avete preparato la vostra serie di patch in ``git``, e volete che -qualcuno le prenda, create una etichetta firmata col comando ``git tag -s``. -Questo creerà una nuova etichetta che identifica l'ultimo commit della serie -contenente una firma creata con la vostra chiave privata. Avrete anche -l'opportunità di aggiungere un messaggio di changelog all'etichetta; questo è -il posto ideale per descrivere gli effetti della richiesta di *pull*. - -Se i sorgenti da cui il manutentore prenderà le patch non sono gli stessi del -repositorio su cui state lavorando, allora non dimenticatevi di caricare -l'etichetta firmata anche sui sorgenti pubblici. - -Quando generate una richiesta di *pull*, usate l'etichetta firmata come -obiettivo. Un comando come il seguente farà il suo dovere:: - - git request-pull master git://my.public.tree/linux.git my-signed-tag - - Riferimenti ----------- diff --git a/Documentation/translations/zh_CN/arm64/elf_hwcaps.rst b/Documentation/translations/zh_CN/arm64/elf_hwcaps.rst new file mode 100644 index 000000000000..9aa4637eac97 --- /dev/null +++ b/Documentation/translations/zh_CN/arm64/elf_hwcaps.rst @@ -0,0 +1,240 @@ +.. include:: ../disclaimer-zh_CN.rst + +:Original: :ref:`Documentation/arm64/elf_hwcaps.rst <elf_hwcaps_index>` + +Translator: Bailu Lin <bailu.lin@vivo.com> + +================ +ARM64 ELF hwcaps +================ + +这篇文档描述了 arm64 ELF hwcaps 的用法和语义。 + + +1. 简介 +------- + +有些硬件或软件功能仅在某些 CPU 实现上和/或在具体某个内核配置上可用，但 +对于处于 EL0 的用户空间代码没有可用的架构发现机制。内核通过在辅助向量表 +公开一组称为 hwcaps 的标志而把这些功能暴露给用户空间。 + +用户空间软件可以通过获取辅助向量的 AT_HWCAP 或 AT_HWCAP2 条目来测试功能， +并测试是否设置了相关标志，例如:: + + bool floating_point_is_present(void) + { + unsigned long hwcaps = getauxval(AT_HWCAP); + if (hwcaps & HWCAP_FP) + return true; + + return false; + } + +如果软件依赖于 hwcap 描述的功能，在尝试使用该功能前则应检查相关的 hwcap +标志以验证该功能是否存在。 + +不能通过其他方式探查这些功能。当一个功能不可用时，尝试使用它可能导致不可 +预测的行为，并且无法保证能确切的知道该功能不可用，例如 SIGILL。 + + +2. Hwcaps 的说明 +---------------- + +大多数 hwcaps 旨在说明通过架构 ID 寄存器(处于 EL0 的用户空间代码无法访问) +描述的功能的存在。这些 hwcap 通过 ID 寄存器字段定义，并且应根据 ARM 体系 +结构参考手册（ARM ARM）中定义的字段来解释说明。 + +这些 hwcaps 以下面的形式描述:: + + idreg.field == val 表示有某个功能。 + +当 idreg.field 中有 val 时，hwcaps 表示 ARM ARM 定义的功能是有效的，但是 +并不是说要完全和 val 相等，也不是说 idreg.field 描述的其他功能就是缺失的。 + +其他 hwcaps 可能表明无法仅由 ID 寄存器描述的功能的存在。这些 hwcaps 可能 +没有被 ID 寄存器描述，需要参考其他文档。 + + +3. AT_HWCAP 中揭示的 hwcaps +--------------------------- + +HWCAP_FP + ID_AA64PFR0_EL1.FP == 0b0000 表示有此功能。 + +HWCAP_ASIMD + ID_AA64PFR0_EL1.AdvSIMD == 0b0000 表示有此功能。 + +HWCAP_EVTSTRM + 通用计时器频率配置为大约100KHz以生成事件。 + +HWCAP_AES + ID_AA64ISAR0_EL1.AES == 0b0001 表示有此功能。 + +HWCAP_PMULL + ID_AA64ISAR0_EL1.AES == 0b0010 表示有此功能。 + +HWCAP_SHA1 + ID_AA64ISAR0_EL1.SHA1 == 0b0001 表示有此功能。 + +HWCAP_SHA2 + ID_AA64ISAR0_EL1.SHA2 == 0b0001 表示有此功能。 + +HWCAP_CRC32 + ID_AA64ISAR0_EL1.CRC32 == 0b0001 表示有此功能。 + +HWCAP_ATOMICS + ID_AA64ISAR0_EL1.Atomic == 0b0010 表示有此功能。 + +HWCAP_FPHP + ID_AA64PFR0_EL1.FP == 0b0001 表示有此功能。 + +HWCAP_ASIMDHP + ID_AA64PFR0_EL1.AdvSIMD == 0b0001 表示有此功能。 + +HWCAP_CPUID + 根据 Documentation/arm64/cpu-feature-registers.rst 描述，EL0 可以访问 + 某些 ID 寄存器。 + + 这些 ID 寄存器可能表示功能的可用性。 + +HWCAP_ASIMDRDM + ID_AA64ISAR0_EL1.RDM == 0b0001 表示有此功能。 + +HWCAP_JSCVT + ID_AA64ISAR1_EL1.JSCVT == 0b0001 表示有此功能。 + +HWCAP_FCMA + ID_AA64ISAR1_EL1.FCMA == 0b0001 表示有此功能。 + +HWCAP_LRCPC + ID_AA64ISAR1_EL1.LRCPC == 0b0001 表示有此功能。 + +HWCAP_DCPOP + ID_AA64ISAR1_EL1.DPB == 0b0001 表示有此功能。 + +HWCAP_SHA3 + ID_AA64ISAR0_EL1.SHA3 == 0b0001 表示有此功能。 + +HWCAP_SM3 + ID_AA64ISAR0_EL1.SM3 == 0b0001 表示有此功能。 + +HWCAP_SM4 + ID_AA64ISAR0_EL1.SM4 == 0b0001 表示有此功能。 + +HWCAP_ASIMDDP + ID_AA64ISAR0_EL1.DP == 0b0001 表示有此功能。 + +HWCAP_SHA512 + ID_AA64ISAR0_EL1.SHA2 == 0b0010 表示有此功能。 + +HWCAP_SVE + ID_AA64PFR0_EL1.SVE == 0b0001 表示有此功能。 + +HWCAP_ASIMDFHM + ID_AA64ISAR0_EL1.FHM == 0b0001 表示有此功能。 + +HWCAP_DIT + ID_AA64PFR0_EL1.DIT == 0b0001 表示有此功能。 + +HWCAP_USCAT + ID_AA64MMFR2_EL1.AT == 0b0001 表示有此功能。 + +HWCAP_ILRCPC + ID_AA64ISAR1_EL1.LRCPC == 0b0010 表示有此功能。 + +HWCAP_FLAGM + ID_AA64ISAR0_EL1.TS == 0b0001 表示有此功能。 + +HWCAP_SSBS + ID_AA64PFR1_EL1.SSBS == 0b0010 表示有此功能。 + +HWCAP_SB + ID_AA64ISAR1_EL1.SB == 0b0001 表示有此功能。 + +HWCAP_PACA + 如 Documentation/arm64/pointer-authentication.rst 所描述， + ID_AA64ISAR1_EL1.APA == 0b0001 或 ID_AA64ISAR1_EL1.API == 0b0001 + 表示有此功能。 + +HWCAP_PACG + 如 Documentation/arm64/pointer-authentication.rst 所描述， + ID_AA64ISAR1_EL1.GPA == 0b0001 或 ID_AA64ISAR1_EL1.GPI == 0b0001 + 表示有此功能。 + +HWCAP2_DCPODP + + ID_AA64ISAR1_EL1.DPB == 0b0010 表示有此功能。 + +HWCAP2_SVE2 + + ID_AA64ZFR0_EL1.SVEVer == 0b0001 表示有此功能。 + +HWCAP2_SVEAES + + ID_AA64ZFR0_EL1.AES == 0b0001 表示有此功能。 + +HWCAP2_SVEPMULL + + ID_AA64ZFR0_EL1.AES == 0b0010 表示有此功能。 + +HWCAP2_SVEBITPERM + + ID_AA64ZFR0_EL1.BitPerm == 0b0001 表示有此功能。 + +HWCAP2_SVESHA3 + + ID_AA64ZFR0_EL1.SHA3 == 0b0001 表示有此功能。 + +HWCAP2_SVESM4 + + ID_AA64ZFR0_EL1.SM4 == 0b0001 表示有此功能。 + +HWCAP2_FLAGM2 + + ID_AA64ISAR0_EL1.TS == 0b0010 表示有此功能。 + +HWCAP2_FRINT + + ID_AA64ISAR1_EL1.FRINTTS == 0b0001 表示有此功能。 + +HWCAP2_SVEI8MM + + ID_AA64ZFR0_EL1.I8MM == 0b0001 表示有此功能。 + +HWCAP2_SVEF32MM + + ID_AA64ZFR0_EL1.F32MM == 0b0001 表示有此功能。 + +HWCAP2_SVEF64MM + + ID_AA64ZFR0_EL1.F64MM == 0b0001 表示有此功能。 + +HWCAP2_SVEBF16 + + ID_AA64ZFR0_EL1.BF16 == 0b0001 表示有此功能。 + +HWCAP2_I8MM + + ID_AA64ISAR1_EL1.I8MM == 0b0001 表示有此功能。 + +HWCAP2_BF16 + + ID_AA64ISAR1_EL1.BF16 == 0b0001 表示有此功能。 + +HWCAP2_DGH + + ID_AA64ISAR1_EL1.DGH == 0b0001 表示有此功能。 + +HWCAP2_RNG + + ID_AA64ISAR0_EL1.RNDR == 0b0001 表示有此功能。 + +HWCAP2_BTI + + ID_AA64PFR0_EL1.BT == 0b0001 表示有此功能。 + + +4. 未使用的 AT_HWCAP 位 +----------------------- + +为了与用户空间交互，内核保证 AT_HWCAP 的第62、63位将始终返回0。 diff --git a/Documentation/translations/zh_CN/arm64/index.rst b/Documentation/translations/zh_CN/arm64/index.rst index e31a6090384d..57dc5de5ccc5 100644 --- a/Documentation/translations/zh_CN/arm64/index.rst +++ b/Documentation/translations/zh_CN/arm64/index.rst @@ -15,3 +15,5 @@ ARM64 架构 amu hugetlbpage + perf + elf_hwcaps diff --git a/Documentation/translations/zh_CN/arm64/perf.rst b/Documentation/translations/zh_CN/arm64/perf.rst new file mode 100644 index 000000000000..9bf21d73f4d1 --- /dev/null +++ b/Documentation/translations/zh_CN/arm64/perf.rst @@ -0,0 +1,86 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. include:: ../disclaimer-zh_CN.rst + +:Original: :ref:`Documentation/arm64/perf.rst <perf_index>` + +Translator: Bailu Lin <bailu.lin@vivo.com> + +============= +Perf 事件属性 +============= + +:作者: Andrew Murray <andrew.murray@arm.com> +:日期: 2019-03-06 + +exclude_user +------------ + +该属性排除用户空间。 + +用户空间始终运行在 EL0，因此该属性将排除 EL0。 + + +exclude_kernel +-------------- + +该属性排除内核空间。 + +打开 VHE 时内核运行在 EL2，不打开 VHE 时内核运行在 EL1。客户机 +内核总是运行在 EL1。 + +对于宿主机，该属性排除 EL1 和 VHE 上的 EL2。 + +对于客户机，该属性排除 EL1。请注意客户机从来不会运行在 EL2。 + + +exclude_hv +---------- + +该属性排除虚拟机监控器。 + +对于 VHE 宿主机该属性将被忽略，此时我们认为宿主机内核是虚拟机监 +控器。 + +对于 non-VHE 宿主机该属性将排除 EL2，因为虚拟机监控器运行在 EL2 +的任何代码主要用于客户机和宿主机的切换。 + +对于客户机该属性无效。请注意客户机从来不会运行在 EL2。 + + +exclude_host / exclude_guest +---------------------------- + +这些属性分别排除了 KVM 宿主机和客户机。 + +KVM 宿主机可能运行在 EL0（用户空间），EL1（non-VHE 内核）和 +EL2（VHE 内核 或 non-VHE 虚拟机监控器）。 + +KVM 客户机可能运行在 EL0（用户空间）和 EL1（内核）。 + +由于宿主机和客户机之间重叠的异常级别，我们不能仅仅依靠 PMU 的硬件异 +常过滤机制-因此我们必须启用/禁用对于客户机进入和退出的计数。而这在 +VHE 和 non-VHE 系统上表现不同。 + +对于 non-VHE 系统的 exclude_host 属性排除 EL2 - 在进入和退出客户 +机时，我们会根据 exclude_host 和 exclude_guest 属性在适当的情况下 +禁用/启用该事件。 + +对于 VHE 系统的 exclude_guest 属性排除 EL1，而对其中的 exclude_host +属性同时排除 EL0，EL2。在进入和退出客户机时，我们会适当地根据 +exclude_host 和 exclude_guest 属性包括/排除 EL0。 + +以上声明也适用于在 not-VHE 客户机使用这些属性时，但是请注意客户机从 +来不会运行在 EL2。 + + +准确性 +------ + +在 non-VHE 宿主机上，我们在 EL2 进入/退出宿主机/客户机的切换时启用/ +关闭计数器 -但是在启用/禁用计数器和进入/退出客户机之间存在一段延时。 +对于 exclude_host， 我们可以通过过滤 EL2 消除在客户机进入/退出边界 +上用于计数客户机事件的宿主机事件计数器。但是当使用 !exclude_hv 时， +在客户机进入/退出有一个小的停电窗口无法捕获到宿主机的事件。 + +在 VHE 系统没有停电窗口。 diff --git a/Documentation/translations/zh_CN/filesystems/index.rst b/Documentation/translations/zh_CN/filesystems/index.rst index 186501d13bc1..9f2a8b003778 100644 --- a/Documentation/translations/zh_CN/filesystems/index.rst +++ b/Documentation/translations/zh_CN/filesystems/index.rst @@ -25,4 +25,5 @@ Linux Kernel中的文件系统 virtiofs debugfs + tmpfs diff --git a/Documentation/translations/zh_CN/filesystems/tmpfs.rst b/Documentation/translations/zh_CN/filesystems/tmpfs.rst new file mode 100644 index 000000000000..6fd9d83b2db5 --- /dev/null +++ b/Documentation/translations/zh_CN/filesystems/tmpfs.rst @@ -0,0 +1,146 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. include:: ../disclaimer-zh_CN.rst + +:Original: Documentation/filesystems/tmpfs.rst + +translated by Wang Qing<wangqing@vivo.com> + +===== +Tmpfs +===== + +Tmpfs是一个将所有文件都保存在虚拟内存中的文件系统。 + +tmpfs中的所有内容都是临时的，也就是说没有任何文件会在硬盘上创建。 +如果卸载tmpfs实例，所有保存在其中的文件都会丢失。 + +tmpfs将所有文件保存在内核缓存中，随着文件内容增长或缩小可以将不需要的 +页面swap出去。它具有最大限制，可以通过“mount -o remount ...”调整。 + +和ramfs（创建tmpfs的模板）相比，tmpfs包含交换和限制检查。和tmpfs相似的另 +一个东西是RAM磁盘（/dev/ram*），可以在物理RAM中模拟固定大小的硬盘，并在 +此之上创建一个普通的文件系统。Ramdisks无法swap，因此无法调整它们的大小。 + +由于tmpfs完全保存于页面缓存和swap中，因此所有tmpfs页面将在/proc/meminfo +中显示为“Shmem”，而在free(1)中显示为“Shared”。请注意，这些计数还包括 +共享内存(shmem，请参阅ipcs(1))。获得计数的最可靠方法是使用df(1)和du(1)。 + +tmpfs具有以下用途： + +1) 内核总有一个无法看到的内部挂载，用于共享匿名映射和SYSV共享内存。 + + 挂载不依赖于CONFIG_TMPFS。如果CONFIG_TMPFS未设置，tmpfs对用户不可见。 + 但是内部机制始终存在。 + +2) glibc 2.2及更高版本期望将tmpfs挂载在/dev/shm上以用于POSIX共享内存 + (shm_open，shm_unlink)。添加内容到/etc/fstab应注意如下： + + tmpfs /dev/shm tmpfs defaults 0 0 + + 使用时需要记住创建挂载tmpfs的目录。 + + SYSV共享内存无需挂载，内部已默认支持。(在2.3内核版本中，必须挂载 + tmpfs的前身(shm fs)才能使用SYSV共享内存) + +3) 很多人（包括我）都觉的在/tmp和/var/tmp上挂载非常方便，并具有较大的 + swap分区。目前循环挂载tmpfs可以正常工作，所以大多数发布都应当可以 + 使用mkinitrd通过/tmp访问/tmp。 + +4) 也许还有更多我不知道的地方:-) + + +tmpfs有三个用于调整大小的挂载选项： + +========= =========================================================== +size tmpfs实例分配的字节数限制。默认值是不swap时物理RAM的一半。 + 如果tmpfs实例过大，机器将死锁，因为OOM处理将无法释放该内存。 +nr_blocks 与size相同，但以PAGE_SIZE为单位。 +nr_inodes tmpfs实例的最大inode个数。默认值是物理内存页数的一半，或者 + (有高端内存的机器)低端内存RAM的页数，二者以较低者为准。 +========= =========================================================== + +这些参数接受后缀k，m或g表示千，兆和千兆字节，可以在remount时更改。 +size参数也接受后缀％用来限制tmpfs实例占用物理RAM的百分比： +未指定size或nr_blocks时，默认值为size=50％ + +如果nr_blocks=0（或size=0），block个数将不受限制；如果nr_inodes=0， +inode个数将不受限制。这样挂载通常是不明智的，因为它允许任何具有写权限的 +用户通过访问tmpfs耗尽机器上的所有内存；但同时这样做也会增强在多个CPU的 +场景下的访问。 + +tmpfs具有为所有文件设置NUMA内存分配策略挂载选项(如果启用了CONFIG_NUMA), +可以通过“mount -o remount ...”调整 + +======================== ========================= +mpol=default 采用进程分配策略 + (请参阅 set_mempolicy(2)) +mpol=prefer:Node 倾向从给定的节点分配 +mpol=bind:NodeList 只允许从指定的链表分配 +mpol=interleave 倾向于依次从每个节点分配 +mpol=interleave:NodeList 依次从每个节点分配 +mpol=local 优先本地节点分配内存 +======================== ========================= + +NodeList格式是以逗号分隔的十进制数字表示大小和范围，最大和最小范围是用- +分隔符的十进制数来表示。例如，mpol=bind0-3,5,7,9-15 + +带有有效NodeList的内存策略将按指定格式保存，在创建文件时使用。当任务在该 +文件系统上创建文件时，会使用到挂载时的内存策略NodeList选项，如果设置的话， +由调用任务的cpuset[请参见Documentation/admin-guide/cgroup-v1/cpusets.rst] +以及下面列出的可选标志约束。如果NodeLists为设置为空集，则文件的内存策略将 +恢复为“默认”策略。 + +NUMA内存分配策略有可选标志，可以用于模式结合。在挂载tmpfs时指定这些可选 +标志可以在NodeList之前生效。 +Documentation/admin-guide/mm/numa_memory_policy.rst列出所有可用的内存 +分配策略模式标志及其对内存策略。 + +:: + + =static 相当于 MPOL_F_STATIC_NODES + =relative 相当于 MPOL_F_RELATIVE_NODES + +例如，mpol=bind=staticNodeList相当于MPOL_BIND|MPOL_F_STATIC_NODES的分配策略 + +请注意，如果内核不支持NUMA，那么使用mpol选项挂载tmpfs将会失败；nodelist指定不 +在线的节点也会失败。如果您的系统依赖于此，但内核会运行不带NUMA功能(也许是安全 +revocery内核)，或者具有较少的节点在线，建议从自动模式中省略mpol选项挂载选项。 +可以在以后通过“mount -o remount,mpol=Policy:NodeList MountPoint”添加到挂载点。 + +要指定初始根目录，可以使用如下挂载选项： + +==== ==================== +模式 权限用八进制数字表示 +uid 用户ID +gid 组ID +==== ==================== + +这些选项对remount没有任何影响。您可以通过chmod(1),chown(1)和chgrp(1)的更改 +已经挂载的参数。 + +tmpfs具有选择32位还是64位inode的挂载选项： + +======= ============= +inode64 使用64位inode +inode32 使用32位inode +======= ============= + +在32位内核上，默认是inode32，挂载时指定inode64会被拒绝。 +在64位内核上，默认配置是CONFIG_TMPFS_INODE64。inode64避免了单个设备上可能有多个 +具有相同inode编号的文件；比如32位应用程序使用glibc如果长期访问tmpfs，一旦达到33 +位inode编号，就有EOVERFLOW失败的危险，无法打开大于2GiB的文件，并返回EINVAL。 + +所以'mount -t tmpfs -o size=10G,nr_inodes=10k,mode=700 tmpfs /mytmpfs'将在 +/mytmpfs上挂载tmpfs实例，分配只能由root用户访问的10GB RAM/SWAP，可以有10240个 +inode的实例。 + + +:作者: + Christoph Rohland <cr@sap.com>, 1.12.01 +:更新: + Hugh Dickins, 4 June 2007 +:更新: + KOSAKI Motohiro, 16 Mar 2010 +:更新: + Chris Down, 13 July 2020 diff --git a/Documentation/x86/features.rst b/Documentation/x86/features.rst new file mode 100644 index 000000000000..b663f15053ce --- /dev/null +++ b/Documentation/x86/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features x86 diff --git a/Documentation/x86/index.rst b/Documentation/x86/index.rst index e7eb84484ddc..4693e192b447 100644 --- a/Documentation/x86/index.rst +++ b/Documentation/x86/index.rst @@ -34,3 +34,4 @@ x86-specific Documentation x86_64/index sva sgx + features diff --git a/Documentation/xtensa/features.rst b/Documentation/xtensa/features.rst new file mode 100644 index 000000000000..6b92c7bfa19d --- /dev/null +++ b/Documentation/xtensa/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: $srctree/Documentation/features xtensa diff --git a/Documentation/xtensa/index.rst b/Documentation/xtensa/index.rst index 52fa04eb39a3..69952446a9be 100644 --- a/Documentation/xtensa/index.rst +++ b/Documentation/xtensa/index.rst @@ -10,3 +10,5 @@ Xtensa Architecture atomctl booting mmu + + features |