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| author | Mark Brown <broonie@kernel.org> | 2026-03-30 19:59:52 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2026-03-30 19:59:52 +0300 |
| commit | 2a740dc5892a0e90e32ddae4d0ece501ace2adfc (patch) | |
| tree | a1a309c150404c63605140544f60eee9287adf26 /Documentation | |
| parent | 1e28cdeec31333b165f72b6ad647652c4c6f6ff2 (diff) | |
| parent | 8ec017cf31299c4b6287ebe27afe81c986aeef88 (diff) | |
| download | linux-2a740dc5892a0e90e32ddae4d0ece501ace2adfc.tar.xz | |
ASoC: Merge up fixes
Merge branch 'for-7.0' of
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into
asoc-7.1 for both ASoC and general bug fixes to support testing.
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/PCI/pcieaer-howto.rst | 10 | ||||
| -rw-r--r-- | Documentation/core-api/dma-attributes.rst | 38 | ||||
| -rw-r--r-- | Documentation/filesystems/overlayfs.rst | 50 | ||||
| -rw-r--r-- | Documentation/hwmon/adm1177.rst | 8 | ||||
| -rw-r--r-- | Documentation/hwmon/peci-cputemp.rst | 10 | ||||
| -rw-r--r-- | Documentation/userspace-api/landlock.rst | 23 |
6 files changed, 119 insertions, 20 deletions
diff --git a/Documentation/PCI/pcieaer-howto.rst b/Documentation/PCI/pcieaer-howto.rst index 3210c4792978..90fdfddd3ae5 100644 --- a/Documentation/PCI/pcieaer-howto.rst +++ b/Documentation/PCI/pcieaer-howto.rst @@ -85,6 +85,16 @@ In the example, 'Requester ID' means the ID of the device that sent the error message to the Root Port. Please refer to PCIe specs for other fields. +The 'TLP Header' is the prefix/header of the TLP that caused the error +in raw hex format. To decode the TLP Header into human-readable form +one may use tlp-tool: + +https://github.com/mmpg-x86/tlp-tool + +Example usage:: + + curl -L https://git.kernel.org/linus/2ca1c94ce0b6 | rtlp-tool --aer + AER Ratelimits -------------- diff --git a/Documentation/core-api/dma-attributes.rst b/Documentation/core-api/dma-attributes.rst index 1d7bfad73b1c..123c8468d58f 100644 --- a/Documentation/core-api/dma-attributes.rst +++ b/Documentation/core-api/dma-attributes.rst @@ -149,11 +149,33 @@ For architectures that require cache flushing for DMA coherence DMA_ATTR_MMIO will not perform any cache flushing. The address provided must never be mapped cacheable into the CPU. -DMA_ATTR_CPU_CACHE_CLEAN ------------------------- - -This attribute indicates the CPU will not dirty any cacheline overlapping this -DMA_FROM_DEVICE/DMA_BIDIRECTIONAL buffer while it is mapped. This allows -multiple small buffers to safely share a cacheline without risk of data -corruption, suppressing DMA debug warnings about overlapping mappings. -All mappings sharing a cacheline should have this attribute. +DMA_ATTR_DEBUGGING_IGNORE_CACHELINES +------------------------------------ + +This attribute indicates that CPU cache lines may overlap for buffers mapped +with DMA_FROM_DEVICE or DMA_BIDIRECTIONAL. + +Such overlap may occur when callers map multiple small buffers that reside +within the same cache line. In this case, callers must guarantee that the CPU +will not dirty these cache lines after the mappings are established. When this +condition is met, multiple buffers can safely share a cache line without risking +data corruption. + +All mappings that share a cache line must set this attribute to suppress DMA +debug warnings about overlapping mappings. + +DMA_ATTR_REQUIRE_COHERENT +------------------------- + +DMA mapping requests with the DMA_ATTR_REQUIRE_COHERENT fail on any +system where SWIOTLB or cache management is required. This should only +be used to support uAPI designs that require continuous HW DMA +coherence with userspace processes, for example RDMA and DRM. At a +minimum the memory being mapped must be userspace memory from +pin_user_pages() or similar. + +Drivers should consider using dma_mmap_pages() instead of this +interface when building their uAPIs, when possible. + +It must never be used in an in-kernel driver that only works with +kernel memory. diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst index af5a69f87da4..eb846518e6ac 100644 --- a/Documentation/filesystems/overlayfs.rst +++ b/Documentation/filesystems/overlayfs.rst @@ -783,6 +783,56 @@ controlled by the "uuid" mount option, which supports these values: mounted with "uuid=on". +Durability and copy up +---------------------- + +The fsync(2) system call ensures that the data and metadata of a file +are safely written to the backing storage, which is expected to +guarantee the existence of the information post system crash. + +Without an fsync(2) call, there is no guarantee that the observed +data after a system crash will be either the old or the new data, but +in practice, the observed data after crash is often the old or new data +or a mix of both. + +When an overlayfs file is modified for the first time, copy up will +create a copy of the lower file and its parent directories in the upper +layer. Since the Linux filesystem API does not enforce any particular +ordering on storing changes without explicit fsync(2) calls, in case +of a system crash, the upper file could end up with no data at all +(i.e. zeros), which would be an unusual outcome. To avoid this +experience, overlayfs calls fsync(2) on the upper file before completing +data copy up with rename(2) or link(2) to make the copy up "atomic". + +By default, overlayfs does not explicitly call fsync(2) on copied up +directories or on metadata-only copy up, so it provides no guarantee to +persist the user's modification unless the user calls fsync(2). +The fsync during copy up only guarantees that if a copy up is observed +after a crash, the observed data is not zeroes or intermediate values +from the copy up staging area. + +On traditional local filesystems with a single journal (e.g. ext4, xfs), +fsync on a file also persists the parent directory changes, because they +are usually modified in the same transaction, so metadata durability during +data copy up effectively comes for free. Overlayfs further limits risk by +disallowing network filesystems as upper layer. + +Overlayfs can be tuned to prefer performance or durability when storing +to the underlying upper layer. This is controlled by the "fsync" mount +option, which supports these values: + +- "auto": (default) + Call fsync(2) on upper file before completion of data copy up. + No explicit fsync(2) on directory or metadata-only copy up. +- "strict": + Call fsync(2) on upper file and directories before completion of any + copy up. +- "volatile": [*] + Prefer performance over durability (see `Volatile mount`_) + +[*] The mount option "volatile" is an alias to "fsync=volatile". + + Volatile mount -------------- diff --git a/Documentation/hwmon/adm1177.rst b/Documentation/hwmon/adm1177.rst index 1c85a2af92bf..375f6d6e03a7 100644 --- a/Documentation/hwmon/adm1177.rst +++ b/Documentation/hwmon/adm1177.rst @@ -27,10 +27,10 @@ for details. Sysfs entries ------------- -The following attributes are supported. Current maxim attribute +The following attributes are supported. Current maximum attribute is read-write, all other attributes are read-only. -in0_input Measured voltage in microvolts. +in0_input Measured voltage in millivolts. -curr1_input Measured current in microamperes. -curr1_max_alarm Overcurrent alarm in microamperes. +curr1_input Measured current in milliamperes. +curr1_max Overcurrent shutdown threshold in milliamperes. diff --git a/Documentation/hwmon/peci-cputemp.rst b/Documentation/hwmon/peci-cputemp.rst index fe0422248dc5..266b62a46f49 100644 --- a/Documentation/hwmon/peci-cputemp.rst +++ b/Documentation/hwmon/peci-cputemp.rst @@ -51,8 +51,9 @@ temp1_max Provides thermal control temperature of the CPU package temp1_crit Provides shutdown temperature of the CPU package which is also known as the maximum processor junction temperature, Tjmax or Tprochot. -temp1_crit_hyst Provides the hysteresis value from Tcontrol to Tjmax of - the CPU package. +temp1_crit_hyst Provides the hysteresis temperature of the CPU + package. Returns Tcontrol, the temperature at which + the critical condition clears. temp2_label "DTS" temp2_input Provides current temperature of the CPU package scaled @@ -62,8 +63,9 @@ temp2_max Provides thermal control temperature of the CPU package temp2_crit Provides shutdown temperature of the CPU package which is also known as the maximum processor junction temperature, Tjmax or Tprochot. -temp2_crit_hyst Provides the hysteresis value from Tcontrol to Tjmax of - the CPU package. +temp2_crit_hyst Provides the hysteresis temperature of the CPU + package. Returns Tcontrol, the temperature at which + the critical condition clears. temp3_label "Tcontrol" temp3_input Provides current Tcontrol temperature of the CPU diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst index 13134bccdd39..7f86d7a37dc2 100644 --- a/Documentation/userspace-api/landlock.rst +++ b/Documentation/userspace-api/landlock.rst @@ -8,7 +8,7 @@ Landlock: unprivileged access control ===================================== :Author: Mickaël Salaün -:Date: January 2026 +:Date: March 2026 The goal of Landlock is to enable restriction of ambient rights (e.g. global filesystem or network access) for a set of processes. Because Landlock @@ -197,12 +197,27 @@ similar backwards compatibility check is needed for the restrict flags .. code-block:: c - __u32 restrict_flags = LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON; - if (abi < 7) { - /* Clear logging flags unsupported before ABI 7. */ + __u32 restrict_flags = + LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON | + LANDLOCK_RESTRICT_SELF_TSYNC; + switch (abi) { + case 1 ... 6: + /* Removes logging flags for ABI < 7 */ restrict_flags &= ~(LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF | LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON | LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF); + __attribute__((fallthrough)); + case 7: + /* + * Removes multithreaded enforcement flag for ABI < 8 + * + * WARNING: Without this flag, calling landlock_restrict_self(2) is + * only equivalent if the calling process is single-threaded. Below + * ABI v8 (and as of ABI v8, when not using this flag), a Landlock + * policy would only be enforced for the calling thread and its + * children (and not for all threads, including parents and siblings). + */ + restrict_flags &= ~LANDLOCK_RESTRICT_SELF_TSYNC; } The next step is to restrict the current thread from gaining more privileges |
