<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/linux/uaccess.h, branch v7.2-rc1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2026-06-21T20:20:19+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-21T20:20:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2e05544060b9fef5d4d0e0172944e6956c55080f'/>
<id>2e05544060b9fef5d4d0e0172944e6956c55080f</id>
<content type='text'>
Pull non-MM updates from Andrew Morton:

 - "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)

   Fix a taskstats TGID aggregation bug where fields added in the TGID
   query path were not preserved after thread exit, and adds a kselftest
   covering the regression.

 - "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)

   Improve lib/tests/string_helpers_kunit.c a little

 - "lib/base64: decode fixes" (Josh Law)

   Address minor issues in lib/base64.c

 - "selftests/filelock: Make output more kselftestish" (Mark Brown)

   Make the output from the ofdlocks test a bit easier for tooling to
   work with. Also ignore the generated file

 - "uaccess: unify inline vs outline copy_{from,to}_user() selection"
   (Yury Norov)

   Simplify the usercopy code by removing the selectability of inlining
   copy_{from,to}_user().

 - "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)

   Fix a number of possible issues in the ocfs2 xattr code

 - "lib and lib/cmdline enhancements" (Dmitry Antipov)

   Provide additional robustness checking in the cmdline handling code
   and its in-kernel testing and selftests

 - "cleanup the RAID6 P/Q library" (Christoph Hellwig)

   Clean up the RAID6 P/Q library to match the recent updates to the
   RAID 5 XOR library and other CRC/crypto libraries

 - "ocfs2: harden inode validators against forged metadata" (Michael
   Bommarito)

   Add three structural checks to OCFS2 dinode validation so malformed
   on-disk fields are rejected before ocfs2_populate_inode() copies them
   into the in-core inode

 - "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
   Rapoport)

   Clean up the lib/raid code by using kmalloc() in more places

* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
  ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
  ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
  lib: interval_tree_test: validate benchmark parameters
  ocfs2: avoid moving extents to occupied clusters
  treewide: fix transposed "sign" typos and update spelling.txt
  ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
  fat: reject BPB volumes whose data area starts beyond total sectors
  selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
  lib/test_firmware: allocate the configured into_buf size
  fs: efs: remove unneeded debug prints
  checkpatch: cuppress warnings when Reported-by: is followed by Link:
  MAINTAINERS: add Alexander as a kcov reviewer
  mailmap: update Alexander Sverdlin's Email addresses
  fs: fat: inode: replace sprintf() with scnprintf()
  ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
  ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
  ocfs2/dlm: require a ref for locking_state debugfs open
  ocfs2: reject FITRIM ranges shorter than a cluster
  ocfs2: validate fast symlink target during inode read
  ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull non-MM updates from Andrew Morton:

 - "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)

   Fix a taskstats TGID aggregation bug where fields added in the TGID
   query path were not preserved after thread exit, and adds a kselftest
   covering the regression.

 - "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)

   Improve lib/tests/string_helpers_kunit.c a little

 - "lib/base64: decode fixes" (Josh Law)

   Address minor issues in lib/base64.c

 - "selftests/filelock: Make output more kselftestish" (Mark Brown)

   Make the output from the ofdlocks test a bit easier for tooling to
   work with. Also ignore the generated file

 - "uaccess: unify inline vs outline copy_{from,to}_user() selection"
   (Yury Norov)

   Simplify the usercopy code by removing the selectability of inlining
   copy_{from,to}_user().

 - "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)

   Fix a number of possible issues in the ocfs2 xattr code

 - "lib and lib/cmdline enhancements" (Dmitry Antipov)

   Provide additional robustness checking in the cmdline handling code
   and its in-kernel testing and selftests

 - "cleanup the RAID6 P/Q library" (Christoph Hellwig)

   Clean up the RAID6 P/Q library to match the recent updates to the
   RAID 5 XOR library and other CRC/crypto libraries

 - "ocfs2: harden inode validators against forged metadata" (Michael
   Bommarito)

   Add three structural checks to OCFS2 dinode validation so malformed
   on-disk fields are rejected before ocfs2_populate_inode() copies them
   into the in-core inode

 - "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
   Rapoport)

   Clean up the lib/raid code by using kmalloc() in more places

* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
  ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
  ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
  lib: interval_tree_test: validate benchmark parameters
  ocfs2: avoid moving extents to occupied clusters
  treewide: fix transposed "sign" typos and update spelling.txt
  ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
  fat: reject BPB volumes whose data area starts beyond total sectors
  selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
  lib/test_firmware: allocate the configured into_buf size
  fs: efs: remove unneeded debug prints
  checkpatch: cuppress warnings when Reported-by: is followed by Link:
  MAINTAINERS: add Alexander as a kcov reviewer
  mailmap: update Alexander Sverdlin's Email addresses
  fs: fat: inode: replace sprintf() with scnprintf()
  ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
  ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
  ocfs2/dlm: require a ref for locking_state debugfs open
  ocfs2: reject FITRIM ranges shorter than a cluster
  ocfs2: validate fast symlink target during inode read
  ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-06-15T08:51:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-15T08:51:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=764e77d868a5b932c709e20ddb5993f9111a841c'/>
<id>764e77d868a5b932c709e20ddb5993f9111a841c</id>
<content type='text'>
Pull locking updates from Ingo Molnar:
 "Futex updates:

   - Optimize futex hash bucket access patterns (Peter Zijlstra)

   - Large series to address the robust futex unlock race for real, by
     Thomas Gleixner:

      "The robust futex unlock mechanism is racy in respect to the
       clearing of the robust_list_head::list_op_pending pointer because
       unlock and clearing the pointer are not atomic.

       The race window is between the unlock and clearing the pending op
       pointer. If the task is forced to exit in this window, exit will
       access a potentially invalid pending op pointer when cleaning up
       the robust list.

       That happens if another task manages to unmap the object
       containing the lock before the cleanup, which results in an UAF.

       In the worst case this UAF can lead to memory corruption when
       unrelated content has been mapped to the same address by the time
       the access happens.

       User space can't solve this problem without help from the kernel.
       This series provides the kernel side infrastructure to help it
       along:

        1) Combined unlock, pointer clearing, wake-up for the
           contended case

        2) VDSO based unlock and pointer clearing helpers with a
           fix-up function in the kernel when user space was interrupted
           within the critical section.

      ... with help by André Almeida:

        - Add a note about robust list race condition (André Almeida)
        - Add self-tests for robust release operations (André Almeida)

  Context analysis updates:

   - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche)
   - Bump required Clang version to 23 (Marco Elver)

  Guard infrastructure updates:

   - Series to remove NULL check from unconditional guards (Dmitry
     Ilvokhin)

  Lockdep updates:

   - Restore self-test migrate_disable() and sched_rt_mutex state on
     PREEMPT_RT (Karl Mehltretter)

  Membarriers updates:

   - Use per-CPU mutexes for targeted commands (Aniket Gattani)
   - Modernize membarrier_global_expedited with cleanup guards (Aniket
     Gattani)
   - Add rseq stress test for CFS throttle interactions (Aniket Gattani)

  percpu-rwsems updates:

   - Extract __percpu_up_read() to optimize inlining overhead (Dmitry
     Ilvokhin)

  Seqlocks updates:

   - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)

  Lock tracing:

   - Add contended_release tracepoint to sleepable locks such as
     mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry
     Ilvokhin)

  MAINTAINERS updates:

   - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)

  Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra,
  Dmitry Ilvokhin and Peter Zijlstra"

* tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits)
  locking: Add contended_release tracepoint to sleepable locks
  locking/percpu-rwsem: Extract __percpu_up_read()
  tracing/lock: Remove unnecessary linux/sched.h include
  futex: Optimize futex hash bucket access patterns
  rust: sync: completion: Mark inline complete_all and wait_for_completion
  MAINTAINERS: Add RUST [SYNC] entry
  cleanup: Specify nonnull argument index
  selftests: futex: Add tests for robust release operations
  Documentation: futex: Add a note about robust list race condition
  x86/vdso: Implement __vdso_futex_robust_try_unlock()
  x86/vdso: Prepare for robust futex unlock support
  futex: Provide infrastructure to plug the non contended robust futex unlock race
  futex: Add robust futex unlock IP range
  futex: Add support for unlocking robust futexes
  futex: Cleanup UAPI defines
  x86: Select ARCH_MEMORY_ORDER_TSO
  uaccess: Provide unsafe_atomic_store_release_user()
  futex: Provide UABI defines for robust list entry modifiers
  futex: Move futex related mm_struct data into a struct
  futex: Make futex_mm_init() void
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking updates from Ingo Molnar:
 "Futex updates:

   - Optimize futex hash bucket access patterns (Peter Zijlstra)

   - Large series to address the robust futex unlock race for real, by
     Thomas Gleixner:

      "The robust futex unlock mechanism is racy in respect to the
       clearing of the robust_list_head::list_op_pending pointer because
       unlock and clearing the pointer are not atomic.

       The race window is between the unlock and clearing the pending op
       pointer. If the task is forced to exit in this window, exit will
       access a potentially invalid pending op pointer when cleaning up
       the robust list.

       That happens if another task manages to unmap the object
       containing the lock before the cleanup, which results in an UAF.

       In the worst case this UAF can lead to memory corruption when
       unrelated content has been mapped to the same address by the time
       the access happens.

       User space can't solve this problem without help from the kernel.
       This series provides the kernel side infrastructure to help it
       along:

        1) Combined unlock, pointer clearing, wake-up for the
           contended case

        2) VDSO based unlock and pointer clearing helpers with a
           fix-up function in the kernel when user space was interrupted
           within the critical section.

      ... with help by André Almeida:

        - Add a note about robust list race condition (André Almeida)
        - Add self-tests for robust release operations (André Almeida)

  Context analysis updates:

   - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche)
   - Bump required Clang version to 23 (Marco Elver)

  Guard infrastructure updates:

   - Series to remove NULL check from unconditional guards (Dmitry
     Ilvokhin)

  Lockdep updates:

   - Restore self-test migrate_disable() and sched_rt_mutex state on
     PREEMPT_RT (Karl Mehltretter)

  Membarriers updates:

   - Use per-CPU mutexes for targeted commands (Aniket Gattani)
   - Modernize membarrier_global_expedited with cleanup guards (Aniket
     Gattani)
   - Add rseq stress test for CFS throttle interactions (Aniket Gattani)

  percpu-rwsems updates:

   - Extract __percpu_up_read() to optimize inlining overhead (Dmitry
     Ilvokhin)

  Seqlocks updates:

   - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)

  Lock tracing:

   - Add contended_release tracepoint to sleepable locks such as
     mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry
     Ilvokhin)

  MAINTAINERS updates:

   - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)

  Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra,
  Dmitry Ilvokhin and Peter Zijlstra"

* tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits)
  locking: Add contended_release tracepoint to sleepable locks
  locking/percpu-rwsem: Extract __percpu_up_read()
  tracing/lock: Remove unnecessary linux/sched.h include
  futex: Optimize futex hash bucket access patterns
  rust: sync: completion: Mark inline complete_all and wait_for_completion
  MAINTAINERS: Add RUST [SYNC] entry
  cleanup: Specify nonnull argument index
  selftests: futex: Add tests for robust release operations
  Documentation: futex: Add a note about robust list race condition
  x86/vdso: Implement __vdso_futex_robust_try_unlock()
  x86/vdso: Prepare for robust futex unlock support
  futex: Provide infrastructure to plug the non contended robust futex unlock race
  futex: Add robust futex unlock IP range
  futex: Add support for unlocking robust futexes
  futex: Cleanup UAPI defines
  x86: Select ARCH_MEMORY_ORDER_TSO
  uaccess: Provide unsafe_atomic_store_release_user()
  futex: Provide UABI defines for robust list entry modifiers
  futex: Move futex related mm_struct data into a struct
  futex: Make futex_mm_init() void
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>uaccess: Provide unsafe_atomic_store_release_user()</title>
<updated>2026-06-03T09:38:50+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@kernel.org</email>
</author>
<published>2026-06-02T09:09:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6149fc36c09b91050b62e8e68a91027df8df7345'/>
<id>6149fc36c09b91050b62e8e68a91027df8df7345</id>
<content type='text'>
The upcoming support for unlocking robust futexes in the kernel requires
store release semantics. Syscalls do not imply memory ordering on all
architectures so the unlock operation requires a barrier.

This barrier can be avoided when stores imply release like on x86.

Provide a generic version with a smp_mb() before the unsafe_put_user(),
which can be overridden by architectures.

Provide also a ARCH_MEMORY_ORDER_TSO Kconfig option, which can be selected
by architectures with Total Store Order (TSO), where store implies release,
so that the smp_mb() in the generic implementation can be avoided.

If that is set a barrier() is used instead of smp_mb(), which is not
required for the use case at hand, but makes it future proof for other
usage to prevent the compiler from reordering.

Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: André Almeida &lt;andrealmeid@igalia.com&gt;
Link: https://patch.msgid.link/20260602090535.513181528@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The upcoming support for unlocking robust futexes in the kernel requires
store release semantics. Syscalls do not imply memory ordering on all
architectures so the unlock operation requires a barrier.

This barrier can be avoided when stores imply release like on x86.

Provide a generic version with a smp_mb() before the unsafe_put_user(),
which can be overridden by architectures.

Provide also a ARCH_MEMORY_ORDER_TSO Kconfig option, which can be selected
by architectures with Total Store Order (TSO), where store implies release,
so that the smp_mb() in the generic implementation can be avoided.

If that is set a barrier() is used instead of smp_mb(), which is not
required for the use case at hand, but makes it future proof for other
usage to prevent the compiler from reordering.

Signed-off-by: Thomas Gleixner &lt;tglx@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: André Almeida &lt;andrealmeid@igalia.com&gt;
Link: https://patch.msgid.link/20260602090535.513181528@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>uaccess: minimize INLINE_COPY_USER-related ifdefery</title>
<updated>2026-05-29T04:24:45+00:00</updated>
<author>
<name>Yury Norov</name>
<email>ynorov@nvidia.com</email>
</author>
<published>2026-04-25T02:08:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bd99fcfc6219ebe36ae4d0bf5333b5ecc17b53df'/>
<id>bd99fcfc6219ebe36ae4d0bf5333b5ecc17b53df</id>
<content type='text'>
Now that we've got the same config selecting inline vs outline
copy_to_user() and copy_from_user(), we can simplify the corresponding
logic in the uaccess.h.

Link: https://lore.kernel.org/20260425020857.356850-4-ynorov@nvidia.com
Fixes: 1f9a8286bc0c ("uaccess: always export _copy_[from|to]_user with CONFIG_RUST")
Signed-off-by: Yury Norov &lt;ynorov@nvidia.com&gt;
Tested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Christophe Leroy (CS GROUP) &lt;chleroy@kernel.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Viktor Malik &lt;vmalik@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that we've got the same config selecting inline vs outline
copy_to_user() and copy_from_user(), we can simplify the corresponding
logic in the uaccess.h.

Link: https://lore.kernel.org/20260425020857.356850-4-ynorov@nvidia.com
Fixes: 1f9a8286bc0c ("uaccess: always export _copy_[from|to]_user with CONFIG_RUST")
Signed-off-by: Yury Norov &lt;ynorov@nvidia.com&gt;
Tested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Christophe Leroy (CS GROUP) &lt;chleroy@kernel.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Viktor Malik &lt;vmalik@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uaccess: unify inline vs outline copy_{from,to}_user() selection</title>
<updated>2026-05-29T04:24:44+00:00</updated>
<author>
<name>Yury Norov</name>
<email>ynorov@nvidia.com</email>
</author>
<published>2026-04-25T02:08:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c02be2ad2b88c67c5d7c06b6aa7083b5b40e1077'/>
<id>c02be2ad2b88c67c5d7c06b6aa7083b5b40e1077</id>
<content type='text'>
The kernel allows arches to select between inline and outline
implementations of the copy_{from,to}_user() by defining individual
INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER, correspondingly.  However,
all arches enable or disable them always together.

Without the real use-case for one helper being inlined while the other
outlined, having independent controls is excessive and error prone.

Switch the codebase to the single unified INLINE_COPY_USER control.

Link: https://lore.kernel.org/20260425020857.356850-3-ynorov@nvidia.com
Signed-off-by: Yury Norov &lt;ynorov@nvidia.com&gt;
Tested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Christophe Leroy (CS GROUP) &lt;chleroy@kernel.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Viktor Malik &lt;vmalik@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The kernel allows arches to select between inline and outline
implementations of the copy_{from,to}_user() by defining individual
INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER, correspondingly.  However,
all arches enable or disable them always together.

Without the real use-case for one helper being inlined while the other
outlined, having independent controls is excessive and error prone.

Switch the codebase to the single unified INLINE_COPY_USER control.

Link: https://lore.kernel.org/20260425020857.356850-3-ynorov@nvidia.com
Signed-off-by: Yury Norov &lt;ynorov@nvidia.com&gt;
Tested-by: Alice Ryhl &lt;aliceryhl@google.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Christophe Leroy (CS GROUP) &lt;chleroy@kernel.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Viktor Malik &lt;vmalik@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uaccess: add copy_struct_{from,to}_bounce_buffer() helpers</title>
<updated>2026-05-11T10:25:31+00:00</updated>
<author>
<name>Stefan Metzmacher</name>
<email>metze@samba.org</email>
</author>
<published>2026-04-07T16:03:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2eef8b32e4c84caa927495f1d9bc9529d2bc5ac6'/>
<id>2eef8b32e4c84caa927495f1d9bc9529d2bc5ac6</id>
<content type='text'>
These are similar to copy_struct_{from,to}_user() but operate
on kernel buffers instead of user buffers.

They can be used when there is a temporary bounce buffer used,
e.g. in msg_control or similar places.

It allows us to have the same logic to handle old vs. current
and current vs. new structures in the same compatible way.

copy_struct_from_sockptr() will also be able to
use copy_struct_from_bounce_buffer() for the kernel
case as follow us patch.

I'll use this in my IPPROTO_SMBDIRECT work,
but maybe it will also be useful for others...
IPPROTO_QUIC will likely also use it.

Cc: Dmitry Safonov &lt;0x7f454c46@gmail.com&gt;
Cc: Dmitry Safonov &lt;dima@arista.com&gt;
Cc: Francesco Ruggeri &lt;fruggeri@arista.com&gt;
Cc: Salam Noureddine &lt;noureddine@arista.com&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Michal Luczaj &lt;mhal@rbox.co&gt;
Cc: David Wei &lt;dw@davidwei.uk&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.dentz@gmail.com&gt;
Cc: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Cc: Xin Long &lt;lucien.xin@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Cc: Paolo Abeni &lt;pabeni@redhat.com&gt;
Cc: Willem de Bruijn &lt;willemb@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Jakub Kicinski &lt;kuba@kernel.org&gt;
Cc: Simon Horman &lt;horms@kernel.org&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
CC: Kees Cook &lt;keescook@chromium.org&gt;
Cc: netdev@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Stefan Metzmacher &lt;metze@samba.org&gt;
Link: https://patch.msgid.link/f29570914590c50b9b6f451eb3a38d0fe1d954df.1775576651.git.metze@samba.org
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
These are similar to copy_struct_{from,to}_user() but operate
on kernel buffers instead of user buffers.

They can be used when there is a temporary bounce buffer used,
e.g. in msg_control or similar places.

It allows us to have the same logic to handle old vs. current
and current vs. new structures in the same compatible way.

copy_struct_from_sockptr() will also be able to
use copy_struct_from_bounce_buffer() for the kernel
case as follow us patch.

I'll use this in my IPPROTO_SMBDIRECT work,
but maybe it will also be useful for others...
IPPROTO_QUIC will likely also use it.

Cc: Dmitry Safonov &lt;0x7f454c46@gmail.com&gt;
Cc: Dmitry Safonov &lt;dima@arista.com&gt;
Cc: Francesco Ruggeri &lt;fruggeri@arista.com&gt;
Cc: Salam Noureddine &lt;noureddine@arista.com&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Michal Luczaj &lt;mhal@rbox.co&gt;
Cc: David Wei &lt;dw@davidwei.uk&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.dentz@gmail.com&gt;
Cc: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Cc: Xin Long &lt;lucien.xin@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Cc: Paolo Abeni &lt;pabeni@redhat.com&gt;
Cc: Willem de Bruijn &lt;willemb@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Jakub Kicinski &lt;kuba@kernel.org&gt;
Cc: Simon Horman &lt;horms@kernel.org&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
CC: Kees Cook &lt;keescook@chromium.org&gt;
Cc: netdev@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Stefan Metzmacher &lt;metze@samba.org&gt;
Link: https://patch.msgid.link/f29570914590c50b9b6f451eb3a38d0fe1d954df.1775576651.git.metze@samba.org
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uaccess: fix ignored_trailing logic in copy_struct_to_user()</title>
<updated>2026-05-11T10:25:30+00:00</updated>
<author>
<name>Stefan Metzmacher</name>
<email>metze@samba.org</email>
</author>
<published>2026-04-07T16:03:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4911de3145a797389577abfdf9a5185d36cc18d7'/>
<id>4911de3145a797389577abfdf9a5185d36cc18d7</id>
<content type='text'>
Currently all callers pass ignored_trailing=NULL, but I have
code that will make use of.

Now it actually behaves like documented:

* If @usize &lt; @ksize, then the kernel is trying to pass userspace a newer
  struct than it supports. Thus we only copy the interoperable portions
  (@usize) and ignore the rest (but @ignored_trailing is set to %true if
  any of the trailing (@ksize - @usize) bytes are non-zero).

Fixes: 424a55a4a908 ("uaccess: add copy_struct_to_user helper")
Cc: Dmitry Safonov &lt;0x7f454c46@gmail.com&gt;
Cc: Dmitry Safonov &lt;dima@arista.com&gt;
Cc: Francesco Ruggeri &lt;fruggeri@arista.com&gt;
Cc: Salam Noureddine &lt;noureddine@arista.com&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Michal Luczaj &lt;mhal@rbox.co&gt;
Cc: David Wei &lt;dw@davidwei.uk&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.dentz@gmail.com&gt;
Cc: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Cc: Xin Long &lt;lucien.xin@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Cc: Paolo Abeni &lt;pabeni@redhat.com&gt;
Cc: Willem de Bruijn &lt;willemb@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Jakub Kicinski &lt;kuba@kernel.org&gt;
Cc: Simon Horman &lt;horms@kernel.org&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
CC: Kees Cook &lt;keescook@chromium.org&gt;
Cc: netdev@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Stefan Metzmacher &lt;metze@samba.org&gt;
Link: https://patch.msgid.link/71f69442410c1186ed8ce6d5b4b9d4a5a70edbad.1775576651.git.metze@samba.org
Reviewed-by: Aleksa Sarai &lt;aleksa@amutable.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently all callers pass ignored_trailing=NULL, but I have
code that will make use of.

Now it actually behaves like documented:

* If @usize &lt; @ksize, then the kernel is trying to pass userspace a newer
  struct than it supports. Thus we only copy the interoperable portions
  (@usize) and ignore the rest (but @ignored_trailing is set to %true if
  any of the trailing (@ksize - @usize) bytes are non-zero).

Fixes: 424a55a4a908 ("uaccess: add copy_struct_to_user helper")
Cc: Dmitry Safonov &lt;0x7f454c46@gmail.com&gt;
Cc: Dmitry Safonov &lt;dima@arista.com&gt;
Cc: Francesco Ruggeri &lt;fruggeri@arista.com&gt;
Cc: Salam Noureddine &lt;noureddine@arista.com&gt;
Cc: David Ahern &lt;dsahern@kernel.org&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Michal Luczaj &lt;mhal@rbox.co&gt;
Cc: David Wei &lt;dw@davidwei.uk&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
Cc: Luiz Augusto von Dentz &lt;luiz.dentz@gmail.com&gt;
Cc: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Cc: Xin Long &lt;lucien.xin@gmail.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Cc: Paolo Abeni &lt;pabeni@redhat.com&gt;
Cc: Willem de Bruijn &lt;willemb@google.com&gt;
Cc: Neal Cardwell &lt;ncardwell@google.com&gt;
Cc: Jakub Kicinski &lt;kuba@kernel.org&gt;
Cc: Simon Horman &lt;horms@kernel.org&gt;
Cc: Aleksa Sarai &lt;cyphar@cyphar.com&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
CC: Kees Cook &lt;keescook@chromium.org&gt;
Cc: netdev@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Stefan Metzmacher &lt;metze@samba.org&gt;
Link: https://patch.msgid.link/71f69442410c1186ed8ce6d5b4b9d4a5a70edbad.1775576651.git.metze@samba.org
Reviewed-by: Aleksa Sarai &lt;aleksa@amutable.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'nocache-cleanup'</title>
<updated>2026-04-13T15:39:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-04-13T15:39:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fdcbb1bc06508eb7ad961b3876b16382ae678ef8'/>
<id>fdcbb1bc06508eb7ad961b3876b16382ae678ef8</id>
<content type='text'>
This series cleans up some of the special user copy functions naming and
semantics.  In particular, get rid of the (very traditional) double
underscore names and behavior: the whole "optimize away the range check"
model has been largely excised from the other user accessors because
it's so subtle and can be unsafe, but also because it's just not a
relevant optimization any more.

To do that, a couple of drivers that misused the "user" copies as kernel
copies in order to get non-temporal stores had to be fixed up, but that
kind of code should never have been allowed anyway.

The x86-only "nocache" version was also renamed to more accurately
reflect what it actually does.

This was all done because I looked at this code due to a report by Jann
Horn, and I just couldn't stand the inconsistent naming, the horrible
semantics, and the random misuse of these functions.  This code should
probably be cleaned up further, but it's at least slightly closer to
normal semantics.

I had a more intrusive series that went even further in trying to
normalize the semantics, but that ended up hitting so many other
inconsistencies between different architectures in this area (eg
'size_t' vs 'unsigned long' vs 'int' as size arguments, and various
iovec check differences that Vasily Gorbik pointed out) that I ended up
with this more limited version that fixed the worst of the issues.

Reported-by: Jann Horn &lt;jannh@google.com&gt;
Tested-by: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/all/CAHk-=wgg1QVWNWG-UCFo1hx0zqrPnB3qhPzUTrWNft+MtXQXig@mail.gmail.com/

* nocache-cleanup:
  x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcache
  x86: rename and clean up __copy_from_user_inatomic_nocache()
  x86-64: rename misleadingly named '__copy_user_nocache()' function
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This series cleans up some of the special user copy functions naming and
semantics.  In particular, get rid of the (very traditional) double
underscore names and behavior: the whole "optimize away the range check"
model has been largely excised from the other user accessors because
it's so subtle and can be unsafe, but also because it's just not a
relevant optimization any more.

To do that, a couple of drivers that misused the "user" copies as kernel
copies in order to get non-temporal stores had to be fixed up, but that
kind of code should never have been allowed anyway.

The x86-only "nocache" version was also renamed to more accurately
reflect what it actually does.

This was all done because I looked at this code due to a report by Jann
Horn, and I just couldn't stand the inconsistent naming, the horrible
semantics, and the random misuse of these functions.  This code should
probably be cleaned up further, but it's at least slightly closer to
normal semantics.

I had a more intrusive series that went even further in trying to
normalize the semantics, but that ended up hitting so many other
inconsistencies between different architectures in this area (eg
'size_t' vs 'unsigned long' vs 'int' as size arguments, and various
iovec check differences that Vasily Gorbik pointed out) that I ended up
with this more limited version that fixed the worst of the issues.

Reported-by: Jann Horn &lt;jannh@google.com&gt;
Tested-by: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/all/CAHk-=wgg1QVWNWG-UCFo1hx0zqrPnB3qhPzUTrWNft+MtXQXig@mail.gmail.com/

* nocache-cleanup:
  x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcache
  x86: rename and clean up __copy_from_user_inatomic_nocache()
  x86-64: rename misleadingly named '__copy_user_nocache()' function
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: rename and clean up __copy_from_user_inatomic_nocache()</title>
<updated>2026-03-30T22:05:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-30T20:11:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5de7bcaadf160c1716b20a263cf8f5b06f658959'/>
<id>5de7bcaadf160c1716b20a263cf8f5b06f658959</id>
<content type='text'>
Similarly to the previous commit, this renames the somewhat confusingly
named function.  But in this case, it was at least less confusing: the
__copy_from_user_inatomic_nocache is indeed copying from user memory,
and it is indeed ok to be used in an atomic context, so it will not warn
about it.

But the previous commit also removed the NTB mis-use of the
__copy_from_user_inatomic_nocache() function, and as a result every
call-site is now _actually_ doing a real user copy.  That means that we
can now do the proper user pointer verification too.

End result: add proper address checking, remove the double underscores,
and change the "nocache" to "nontemporal" to more accurately describe
what this x86-only function actually does.  It might be worth noting
that only the target is non-temporal: the actual user accesses are
normal memory accesses.

Also worth noting is that non-x86 targets (and on older 32-bit x86 CPU's
before XMM2 in the Pentium III) we end up just falling back on a regular
user copy, so nothing can actually depend on the non-temporal semantics,
but that has always been true.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Similarly to the previous commit, this renames the somewhat confusingly
named function.  But in this case, it was at least less confusing: the
__copy_from_user_inatomic_nocache is indeed copying from user memory,
and it is indeed ok to be used in an atomic context, so it will not warn
about it.

But the previous commit also removed the NTB mis-use of the
__copy_from_user_inatomic_nocache() function, and as a result every
call-site is now _actually_ doing a real user copy.  That means that we
can now do the proper user pointer verification too.

End result: add proper address checking, remove the double underscores,
and change the "nocache" to "nontemporal" to more accurately describe
what this x86-only function actually does.  It might be worth noting
that only the target is non-temporal: the actual user accesses are
normal memory accesses.

Also worth noting is that non-x86 targets (and on older 32-bit x86 CPU's
before XMM2 in the Pentium III) we end up just falling back on a regular
user copy, so nothing can actually depend on the non-temporal semantics,
but that has always been true.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-hotfixes-stable-2026-03-09-16-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2026-03-10T19:47:56+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-10T19:47:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b4f0dd314b39ea154f62f3bd3115ed0470f9f71e'/>
<id>b4f0dd314b39ea154f62f3bd3115ed0470f9f71e</id>
<content type='text'>
Pull misc fixes from Andrew Morton:
 "15 hotfixes. 6 are cc:stable. 14 are for MM.

  Singletons, with one doubleton - please see the changelogs for details"

* tag 'mm-hotfixes-stable-2026-03-09-16-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  MAINTAINERS, mailmap: update email address for Lorenzo Stoakes
  mm/mmu_notifier: clean up mmu_notifier.h kernel-doc
  uaccess: correct kernel-doc parameter format
  mm/huge_memory: fix a folio_split() race condition with folio_try_get()
  MAINTAINERS: add co-maintainer and reviewer for SLAB ALLOCATOR
  MAINTAINERS: add RELAY entry
  memcg: fix slab accounting in refill_obj_stock() trylock path
  mm/hugetlb.c: use __pa() instead of virt_to_phys() in early bootmem alloc code
  zram: rename writeback_compressed device attr
  tools/testing: fix testing/vma and testing/radix-tree build
  Revert "ptdesc: remove references to folios from __pagetable_ctor() and pagetable_dtor()"
  mm/cma: move put_page_testzero() out of VM_WARN_ON in cma_release()
  mm/damon/core: clear walk_control on inactive context in damos_walk()
  mm: memfd_luo: always dirty all folios
  mm: memfd_luo: always make all folios uptodate
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull misc fixes from Andrew Morton:
 "15 hotfixes. 6 are cc:stable. 14 are for MM.

  Singletons, with one doubleton - please see the changelogs for details"

* tag 'mm-hotfixes-stable-2026-03-09-16-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  MAINTAINERS, mailmap: update email address for Lorenzo Stoakes
  mm/mmu_notifier: clean up mmu_notifier.h kernel-doc
  uaccess: correct kernel-doc parameter format
  mm/huge_memory: fix a folio_split() race condition with folio_try_get()
  MAINTAINERS: add co-maintainer and reviewer for SLAB ALLOCATOR
  MAINTAINERS: add RELAY entry
  memcg: fix slab accounting in refill_obj_stock() trylock path
  mm/hugetlb.c: use __pa() instead of virt_to_phys() in early bootmem alloc code
  zram: rename writeback_compressed device attr
  tools/testing: fix testing/vma and testing/radix-tree build
  Revert "ptdesc: remove references to folios from __pagetable_ctor() and pagetable_dtor()"
  mm/cma: move put_page_testzero() out of VM_WARN_ON in cma_release()
  mm/damon/core: clear walk_control on inactive context in damos_walk()
  mm: memfd_luo: always dirty all folios
  mm: memfd_luo: always make all folios uptodate
</pre>
</div>
</content>
</entry>
</feed>
