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2020-03-05bpf, doc: Add BPF JIT for RV32G to BPF documentationLuke Nelson1-1/+2
Update filter.txt and admin-guide to mention the BPF JIT for RV32G. Co-developed-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Luke Nelson <luke.r.nels@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Björn Töpel <bjorn.topel@gmail.com> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20200305050207.4159-4-luke.r.nels@gmail.com
2020-03-04of: property: Delete of_devlink kernel commandline optionSaravana Kannan1-6/+0
With the addition of fw_devlink kernel commandline option, of_devlink is redundant and not useful anymore. So, delete it. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20200222014038.180923-6-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04driver core: Add fw_devlink kernel commandline optionSaravana Kannan1-0/+18
fwnode_operations.add_links allows creating device links from information provided by firmware. fwnode_operations.add_links is currently implemented only by OF/devicetree code and a specific case of efi. However, there's nothing preventing ACPI or other firmware types from implementing it. The OF implementation is currently controlled by a kernel commandline parameter called of_devlink. Since this feature is generic isn't limited to OF, add a generic fw_devlink kernel commandline parameter to control this feature across firmware types. Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20200222014038.180923-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-02Documentation: nfsroot.rst: Fix references to nfsroot.rstNiklas Söderlund1-4/+4
When converting and moving nfsroot.txt to nfsroot.rst the references to the old text file was not updated to match the change, fix this. Fixes: f9a9349846f92b2d ("Documentation: nfsroot.txt: convert to ReST") Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20200212181332.520545-1-niklas.soderlund+renesas@ragnatech.se Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02Documentation: kthread: Fix WQ_SYSFS workqueues path nameZenghui Yu1-1/+1
The set of WQ_SYSFS workqueues should be displayed using "ls /sys/devices/virtual/workqueue", add the missing '/'. Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20200225124052.1506-1-yuzenghui@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02doc: cgroup: improve formatting of referencesJakub Kicinski2-4/+6
Annotate references to other documents to make them clickable. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20200228000653.1572553-6-kuba@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02doc: cgroup: improve formatting of cpuset examplesJakub Kicinski1-2/+2
We need literal sections otherwise the entire example is rendered as a single line. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20200228000653.1572553-5-kuba@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02doc: cgroup: improve formatting of io exampleJakub Kicinski1-1/+1
We need a literal section, like few paragraphs below. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20200228000653.1572553-4-kuba@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02doc: cgroup: improve formatting of mem statsJakub Kicinski1-12/+0
If there is an empty line between item and description Sphinx does not emphasize the item. First half of the list does not have the empty line and is emphasized correctly. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20200228000653.1572553-3-kuba@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02doc: cgroup: improve formattingJakub Kicinski1-1/+1
Fix tabs vs spaces issue which cases the line to be considered a new list entry. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20200228000653.1572553-2-kuba@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02docs: admin-guide: kernel-parameters: Document earlycon options for i.MX UARTsJonathan Neuschäfer1-0/+6
drivers/tty/serial/imx.c implements these earlycon options. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Link: https://lore.kernel.org/r/20200229132750.2783-1-j.neuschaefer@gmx.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-03-02Documentation: cpufreq: Move legacy driver documentationRafael J. Wysocki2-0/+275
There are three legacy driver documents in Documentation/cpu-freq/ that were added years ago and converting them each to the .rst format is rather pointless, even though there is some value in preserving them. However, if they are preserved, they need to go into the admin-guide part of cpufreq documentation where they belong (at least to a certain extent). To preserve them with minimum amount of changes and put them into the right place, and make it possible to process them into HTML (and other formats) along with the rest of the documentation, move them each as a "literal text" block into a separate section of a single .rst "wrapper" file under Documentation/admin-guide/pm/. While at it, repair the PCC specification URL in one of them. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-28Merge tag 'acpi-5.6-rc4' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI fixes from Rafael Wysocki: "Fix a couple of configuration issues in the ACPI watchdog (WDAT) driver (Mika Westerberg) and make it possible to disable that driver at boot time in case it still does not work as expected (Jean Delvare)" * tag 'acpi-5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: watchdog: Set default timeout in probe ACPI: watchdog: Fix gas->access_width usage ACPICA: Introduce ACPI_ACCESS_BYTE_WIDTH() macro ACPI: watchdog: Allow disabling WDAT at boot
2020-02-27s390/protvirt: introduce host side setupVasily Gorbik1-0/+5
Add "prot_virt" command line option which controls if the kernel protected VMs support is enabled at early boot time. This has to be done early, because it needs large amounts of memory and will disable some features like STP time sync for the lpar. Extend ultravisor info definitions and expose it via uv_info struct filled in during startup. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-26Merge tag 'trace-v5.6-rc2' of ↵Linus Torvalds1-3/+31
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing and bootconfig updates: "Fixes and changes to bootconfig before it goes live in a release. Change in API of bootconfig (before it comes live in a release): - Have a magic value "BOOTCONFIG" in initrd to know a bootconfig exists - Set CONFIG_BOOT_CONFIG to 'n' by default - Show error if "bootconfig" on cmdline but not compiled in - Prevent redefining the same value - Have a way to append values - Added a SELECT BLK_DEV_INITRD to fix a build failure Synthetic event fixes: - Switch to raw_smp_processor_id() for recording CPU value in preempt section. (No care for what the value actually is) - Fix samples always recording u64 values - Fix endianess - Check number of values matches number of fields - Fix a printing bug Fix of trace_printk() breaking postponed start up tests Make a function static that is only used in a single file" * tag 'trace-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: bootconfig: Fix CONFIG_BOOTTIME_TRACING dependency issue bootconfig: Add append value operator support bootconfig: Prohibit re-defining value on same key bootconfig: Print array as multiple commands for legacy command line bootconfig: Reject subkey and value on same parent key tools/bootconfig: Remove unneeded error message silencer bootconfig: Add bootconfig magic word for indicating bootconfig explicitly bootconfig: Set CONFIG_BOOT_CONFIG=n by default tracing: Clear trace_state when starting trace bootconfig: Mark boot_config_checksum() static tracing: Disable trace_printk() on post poned tests tracing: Have synthetic event test use raw_smp_processor_id() tracing: Fix number printing bug in print_synth_event() tracing: Check that number of vals matches number of synth event fields tracing: Make synth_event trace functions endian-correct tracing: Make sure synth_event_trace() example always uses u64
2020-02-25docs: add a script to check sysctl docsStephen Kitt1-0/+3
This script allows sysctl documentation to be checked against the kernel source code, to identify missing or obsolete entries. Running it against 5.5 shows for example that sysctl/kernel.rst has two obsolete entries and is missing 52 entries. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-25Documentation: fix a typo for intel_iommu=nobounceAlex Hung1-1/+1
"untrusted" was mis-spelled as "unstrusted" Signed-off-by: Alex Hung <alex.hung@canonical.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-25docs: sysctl/kernel: document acpi_video_flagsStephen Kitt1-2/+9
Based on the implementation in arch/x86/kernel/acpi/sleep.c, in particular the acpi_sleep_setup() function. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-21bootconfig: Add append value operator supportMasami Hiramatsu1-1/+9
Add append value operator "+=" support to bootconfig syntax. With this operator, user can add new value to the key as an entry of array instead of overwriting. For example, foo = bar ... foo += baz Then the key "foo" has "bar" and "baz" values as an array. Link: http://lkml.kernel.org/r/158227283195.12842.8310503105963275584.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-21bootconfig: Prohibit re-defining value on same keyMasami Hiramatsu1-1/+10
Currently, bootconfig adds a new value on the existing key to the tail of an array. But this looks a bit confusing because an admin can easily rewrite the original value in the same config file. This rejects the following value re-definition. key = value1 ... key = value2 You should rewrite value1 to value2 in this case. Link: http://lkml.kernel.org/r/158227282199.12842.10110929876059658601.stgit@devnote2 Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> [ Fixed spelling of arraies to arrays ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-21torture: Allow disabling of boottime CPU-hotplug torture operationsPaul E. McKenney1-0/+4
In theory, RCU-hotplug operations are supposed to work as soon as there is more than one CPU online. However, in practice, in normal production there is no way to make them happen until userspace is up and running. Besides which, on smaller systems, rcutorture doesn't start doing hotplug operations until 30 seconds after the start of boot, which on most systems also means the better part of 30 seconds after the end of boot. This commit therefore provides a new torture.disable_onoff_at_boot kernel boot parameter that suppresses CPU-hotplug torture operations until about the time that init is spawned. Of course, if you know of a need for boottime CPU-hotplug operations, then you should avoid passing this argument to any of the torture tests. You might also want to look at the splats linked to below. Link: https://lore.kernel.org/lkml/20191206185208.GA25636@paulmck-ThinkPad-P72/ Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-21rcutorture: Allow boottime stall warnings to be suppressedPaul E. McKenney1-0/+6
In normal production, an RCU CPU stall warning at boottime is often just as bad as at any other time. In fact, given the desire for fast boot, any sort of long-term stall at boot is a bad idea. However, heavy rcutorture testing on large hyperthreaded systems can generate boottime RCU CPU stalls as a matter of course. This commit therefore provides a kernel boot parameter that suppresses reporting of boottime RCU CPU stall warnings and similarly of rcutorture writer stalls. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-21rcu: React to callback overload by aggressively seeking quiescent statesPaul E. McKenney1-0/+9
In default configutions, RCU currently waits at least 100 milliseconds before asking cond_resched() and/or resched_rcu() for help seeking quiescent states to end a grace period. But 100 milliseconds can be one good long time during an RCU callback flood, for example, as can happen when user processes repeatedly open and close files in a tight loop. These 100-millisecond gaps in successive grace periods during a callback flood can result in excessive numbers of callbacks piling up, unnecessarily increasing memory footprint. This commit therefore asks cond_resched() and/or resched_rcu() for help as early as the first FQS scan when at least one of the CPUs has more than 20,000 callbacks queued, a number that can be changed using the new rcutree.qovld kernel boot parameter. An auxiliary qovld_calc variable is used to avoid acquisition of locks that have not yet been initialized. Early tests indicate that this reduces the RCU-callback memory footprint during rcutorture floods by from 50% to 4x, depending on configuration. Reported-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reported-by: Tejun Heo <tj@kernel.org> [ paulmck: Fix bug located by Qian Cai. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Dexuan Cui <decui@microsoft.com> Tested-by: Qian Cai <cai@lca.pw>
2020-02-21bootconfig: Reject subkey and value on same parent keyMasami Hiramatsu1-0/+7
Reject if a value node is mixed with subkey node on same parent key node. A value node can not co-exist with subkey node under some key node, e.g. key = value key.subkey = another-value This is not be allowed because bootconfig API is not designed to handle such case. Link: http://lkml.kernel.org/r/158220115232.26565.7792340045009731803.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-21bootconfig: Add bootconfig magic word for indicating bootconfig explicitlyMasami Hiramatsu1-3/+7
Add bootconfig magic word to the end of bootconfig on initrd image for indicating explicitly the bootconfig is there. Also tools/bootconfig treats wrong size or wrong checksum or parse error as an error, because if there is a bootconfig magic word, there must be a bootconfig. The bootconfig magic word is "#BOOTCONFIG\n", 12 bytes word. Thus the block image of the initrd file with bootconfig is as follows. [Initrd][bootconfig][size][csum][#BOOTCONFIG\n] Link: http://lkml.kernel.org/r/158220112263.26565.3944814205960612841.stgit@devnote2 Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20x86/split_lock: Enable split lock detection by kernelPeter Zijlstra (Intel)1-0/+22
A split-lock occurs when an atomic instruction operates on data that spans two cache lines. In order to maintain atomicity the core takes a global bus lock. This is typically >1000 cycles slower than an atomic operation within a cache line. It also disrupts performance on other cores (which must wait for the bus lock to be released before their memory operations can complete). For real-time systems this may mean missing deadlines. For other systems it may just be very annoying. Some CPUs have the capability to raise an #AC trap when a split lock is attempted. Provide a command line option to give the user choices on how to handle this: split_lock_detect= off - not enabled (no traps for split locks) warn - warn once when an application does a split lock, but allow it to continue running. fatal - Send SIGBUS to applications that cause split lock On systems that support split lock detection the default is "warn". Note that if the kernel hits a split lock in any mode other than "off" it will OOPs. One implementation wrinkle is that the MSR to control the split lock detection is per-core, not per thread. This might result in some short lived races on HT systems in "warn" mode if Linux tries to enable on one thread while disabling on the other. Race analysis by Sean Christopherson: - Toggling of split-lock is only done in "warn" mode. Worst case scenario of a race is that a misbehaving task will generate multiple #AC exceptions on the same instruction. And this race will only occur if both siblings are running tasks that generate split-lock #ACs, e.g. a race where sibling threads are writing different values will only occur if CPUx is disabling split-lock after an #AC and CPUy is re-enabling split-lock after *its* previous task generated an #AC. - Transitioning between off/warn/fatal modes at runtime isn't supported and disabling is tracked per task, so hardware will always reach a steady state that matches the configured mode. I.e. split-lock is guaranteed to be enabled in hardware once all _TIF_SLD threads have been scheduled out. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Co-developed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20200126200535.GB30377@agluck-desk2.amr.corp.intel.com
2020-02-20Documentation/admin-guide/acpi: fix fan_performance_states.rst warningsRandy Dunlap1-2/+2
Fix Sphinx format warnings in fan_performace_states.rst by adding indentation. Documentation/admin-guide/acpi/fan_performance_states.rst:21: WARNING: Literal block ends without a blank line; unexpected unindent. Documentation/admin-guide/acpi/fan_performance_states.rst:41: WARNING: Literal block expected; none found. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-19docs: admin-guide: edid: Clarify where to run "make"Jonathan Neuschäfer1-1/+1
When both the documentation and the data files lived in Documentation/EDID, this wasn't necessary, but both have been moved to other directories in the meantime. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: admin-guide: Move edid.rst from driver-apiJonathan Neuschäfer2-0/+61
This document describes actions that an admin can do, rather than interfaces available to driver developers, so admin-guide seems to be a more appropriate place for it. Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: sysctl/kernel: remove rtsig entriesStephen Kitt1-10/+0
These have no corresponding code in the kernel. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: document panic fully in sysctl/kernel.rstStephen Kitt1-3/+9
The description of panic doesn’t cover all the supported scenarios; this patch fixes that, describing the three possibilities (no reboot, immediate reboot, reboot after a delay). Based on the implementation in kernel/panic.c. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: document stop-a in sysctl/kernel.rstStephen Kitt1-0/+10
This describes the SPARC-specific stop-a sysctl entry, which was previously listed in kernel.rst but not documented. Base on the implementation in arch/sparc/kernel/setup_{32,64}.c and kernel/panic.c. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: add missing IPC documentation in sysctl/kernel.rstStephen Kitt1-0/+12
This adds short descriptions of msgmax, msgmnb, msgmni, and shmmni, which were previously listed in kernel.rst but not described. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: drop l2cr from sysctl/kernel.rstStephen Kitt1-7/+0
The l2cr sysctl entry was removed in commit c2f3dabefa73 ("sysctl: kill binary sysctl KERN_PPC_L2CR"), this removes the corresponding documentation. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: merge debugging-modules.txt into sysctl/kernel.rstStephen Kitt1-1/+13
This fits nicely in sysctl/kernel.rst, merge it (and rephrase it) instead of linking to it. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: pretty up sysctl/kernel.rstStephen Kitt1-495/+492
This updates sysctl/kernel.rst to use ReStructured Text more fully: * the list of files is now the table of contents (old entries with no corresponding sections are added as empty sections for now); * code references and commands are formatted as code, except for function names which end up linked to the appropriate documentation; * links are used to point to other documentation and other sections; * tables are used to make lists of values more readable (as already done for some sections); * in heavily-reworked paragraphs, sentences are wrapped individually, to make future diffs easier to read. The first mention of the kernel version is dropped. The second mention, saying that the document is accurate for 2.2, is preserved for now; I will update that once the document really is accurate for a current kernel release. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-19docs: Fix path to MTD command line partition parserJonathan Neuschäfer1-1/+1
cmdlinepart.c has been moved to drivers/mtd/parsers/. Fixes: a3f12a35c91d ("mtd: parsers: Move CMDLINE parser") Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-14Documentation: PM: QoS: Update to reflect previous code changesRafael J. Wysocki1-37/+36
Update the PM QoS documentation to reflect the previous code changes regarding the removal of PM QoS classes and the CPU latency QoS API rework. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13Documentation: bootconfig: fix Sphinx block warningRandy Dunlap1-1/+1
Fix Sphinx format warning: lnx-56-rc1/Documentation/admin-guide/bootconfig.rst:26: WARNING: Literal block expected; none found. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/r/07b3e31f-9b1e-1876-aa60-4436e4dd6da0@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13docs: admin-guide: Add description of %c corename formatd.hatayama@fujitsu.com1-0/+1
There is somehow no description of %c corename format specifier for /proc/sys/kernel/core_pattern. The %c corename format specifier is used by user-space application such as systemd-coredump, so it should be documented. To find where %c is handled in the kernel source code, look at function format_corename() in fs/coredump.c. Signed-off-by: HATAYAMA Daisuke <d.hatayama@fujitsu.com> Link: https://lore.kernel.org/r/TYAPR01MB4014714BB2ACE425BB6EC6B7951A0@TYAPR01MB4014.jpnprd01.prod.outlook.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13Documentation: zram: fix the description about orig_data_size of mm_statYue Hu1-2/+0
orig_data_size counted the same_pages by commit 51f9f82c855d ("zram: count same page write as page_stored"), so let's fix it. Signed-off-by: Yue Hu <zbestahu@163.com> Link: https://lore.kernel.org/r/20200206111031.9524-1-zbestahu@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-13dynamic_debug: allow to work if debugfs is disabledGreg Kroah-Hartman1-0/+3
With the realization that having debugfs enabled on "production" systems is generally not a good idea, debugfs is being disabled from more and more platforms over time. However, the functionality of dynamic debugging still is needed at times, and since it relies on debugfs for its user api, having debugfs disabled also forces dynamic debug to be disabled. To get around this, also create the "control" file for dynamic_debug in procfs. This allows people turn on debugging as needed at runtime for individual driverfs and subsystems. Reported-by: many different companies Cc: Jason Baron <jbaron@akamai.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200210211142.GB1373304@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-10Documentation,selinux: deprecate setting checkreqprot to 1Stephen Smalley1-0/+1
Deprecate setting the SELinux checkreqprot tunable to 1 via kernel parameter or /sys/fs/selinux/checkreqprot. Setting it to 0 is left intact for compatibility since Android and some Linux distributions do so for security and treat an inability to set it as a fatal error. Eventually setting it to 0 will become a no-op and the kernel will stop using checkreqprot's value internally altogether. checkreqprot was originally introduced as a compatibility mechanism for legacy userspace and the READ_IMPLIES_EXEC personality flag. However, if set to 1, it weakens security by allowing mappings to be made executable without authorization by policy. The default value for the SECURITY_SELINUX_CHECKREQPROT_VALUE config option was changed from 1 to 0 in commit 2a35d196c160e3 ("selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default") and both Android and Linux distributions began explicitly setting /sys/fs/selinux/checkreqprot to 0 some time ago. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-10ACPI: watchdog: Allow disabling WDAT at bootJean Delvare1-0/+4
In case the WDAT interface is broken, give the user an option to ignore it to let a native driver bind to the watchdog device instead. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-07Merge tag 'pm-5.6-rc1-3' of ↵Linus Torvalds3-25/+89
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: - Update the recently merged CPR (Core Power Reduction) support in the AVS (Adaptive Voltage Scaling) subsystem (Brendan Higgins, Nathan Chancellor, Niklas Cassel) - Update the rockchip-io AVS driver (Heiko Stuebner) - Add two more module parameters to intel_idle on top of the recently merged material (Rafael Wysocki) - Clean up a piece of cpuidle documentation and consolidate system sleep states documentation (Rafael Wysocki) * tag 'pm-5.6-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpuidle: Documentation: Clean up PM QoS description Documentation: admin-guide: PM: Update sleep states documentation intel_idle: Introduce 'states_off' module parameter intel_idle: Introduce 'use_acpi' module parameter power: avs: qcom-cpr: Avoid clang -Wsometimes-uninitialized in cpr_scale power: avs: qcom-cpr: add unspecified HAS_IOMEM dependency PM / AVS: rockchip-io: fix the supply naming for the emmc supply on px30 power: avs: qcom-cpr: add a printout after the driver has been initialized
2020-02-07Merge branches 'pm-avs' and 'pm-cpuidle'Rafael J. Wysocki2-8/+30
* pm-avs: power: avs: qcom-cpr: Avoid clang -Wsometimes-uninitialized in cpr_scale power: avs: qcom-cpr: add unspecified HAS_IOMEM dependency PM / AVS: rockchip-io: fix the supply naming for the emmc supply on px30 power: avs: qcom-cpr: add a printout after the driver has been initialized * pm-cpuidle: cpuidle: Documentation: Clean up PM QoS description intel_idle: Introduce 'states_off' module parameter intel_idle: Introduce 'use_acpi' module parameter
2020-02-06Merge tag 'trace-v5.6-2' of ↵Linus Torvalds3-0/+197
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - Added new "bootconfig". This looks for a file appended to initrd to add boot config options, and has been discussed thoroughly at Linux Plumbers. Very useful for adding kprobes at bootup. Only enabled if "bootconfig" is on the real kernel command line. - Created dynamic event creation. Merges common code between creating synthetic events and kprobe events. - Rename perf "ring_buffer" structure to "perf_buffer" - Rename ftrace "ring_buffer" structure to "trace_buffer" Had to rename existing "trace_buffer" to "array_buffer" - Allow trace_printk() to work withing (some) tracing code. - Sort of tracing configs to be a little better organized - Fixed bug where ftrace_graph hash was not being protected properly - Various other small fixes and clean ups * tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits) bootconfig: Show the number of nodes on boot message tools/bootconfig: Show the number of bootconfig nodes bootconfig: Add more parse error messages bootconfig: Use bootconfig instead of boot config ftrace: Protect ftrace_graph_hash with ftrace_sync ftrace: Add comment to why rcu_dereference_sched() is open coded tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu tracing: Annotate ftrace_graph_hash pointer with __rcu bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline tracing: Use seq_buf for building dynevent_cmd string tracing: Remove useless code in dynevent_arg_pair_add() tracing: Remove check_arg() callbacks from dynevent args tracing: Consolidate some synth_event_trace code tracing: Fix now invalid var_ref_vals assumption in trace action tracing: Change trace_boot to use synth_event interface tracing: Move tracing selftests to bottom of menu tracing: Move mmio tracer config up with the other tracers tracing: Move tracing test module configs together tracing: Move all function tracing configs together tracing: Documentation for in-kernel synthetic event API ...
2020-02-05bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdlineSteven Rostedt (VMware)2-0/+8
As the bootconfig is appended to the initrd it is not as easy to modify as the kernel command line. If there's some issue with the kernel, and the developer wants to boot a pristine kernel, it should not be needed to modify the initrd to remove the bootconfig for a single boot. As bootconfig is silently added (if the admin does not know where to look they may not know it's being loaded). It should be explicitly added to the kernel cmdline. The loading of the bootconfig is only done if "bootconfig" is on the kernel command line. This will let admins know that the kernel command line is extended. Note, after adding printk()s for when the size is too great or the checksum is wrong, exposed that the current method always looked for the boot config, and if this size and checksum matched, it would parse it (as if either is wrong a printk has been added to show this). It's better to only check this if the boot config is asked to be looked for. Link: https://lore.kernel.org/r/CAHk-=wjfjO+h6bQzrTf=YCZA53Y3EDyAs3Z4gEsT7icA3u_Psw@mail.gmail.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-05cpuidle: Documentation: Clean up PM QoS descriptionRafael J. Wysocki1-4/+4
Clean up the language in one paragraph in the PM QoS description in Documentation/admin-guide/pm/cpuidle.rst. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-03Documentation: admin-guide: PM: Update sleep states documentationRafael J. Wysocki1-17/+59
There is some information in Documentation/power/interface.rst that is still missing from Documentation/admin-guide/pm/sleep-states.rst and really should be present in there, so update the latter by adding that information to it and delete the former (as it becomes redundant after that and it is somewhat outdated). While at it, clean up some assorted pieces of sleep-states.rst a bit. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>