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authorMark Brown <broonie@kernel.org>2026-03-30 19:59:52 +0300
committerMark Brown <broonie@kernel.org>2026-03-30 19:59:52 +0300
commit2a740dc5892a0e90e32ddae4d0ece501ace2adfc (patch)
treea1a309c150404c63605140544f60eee9287adf26 /Documentation
parent1e28cdeec31333b165f72b6ad647652c4c6f6ff2 (diff)
parent8ec017cf31299c4b6287ebe27afe81c986aeef88 (diff)
downloadlinux-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.rst10
-rw-r--r--Documentation/core-api/dma-attributes.rst38
-rw-r--r--Documentation/filesystems/overlayfs.rst50
-rw-r--r--Documentation/hwmon/adm1177.rst8
-rw-r--r--Documentation/hwmon/peci-cputemp.rst10
-rw-r--r--Documentation/userspace-api/landlock.rst23
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