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()
  ...

strncpy() has been a persistent source of bugs due to its ambiguous
intended usage and frequently counter-intuitive semantics: it may not
NUL-terminate the destination, and it unconditionally zero-pads to the
full length, which isn't always needed. All former callers have been
migrated[1] to:

  - strscpy()        for NUL-terminated destinations
  - strscpy_pad()    for NUL-terminated destinations needing zero-padding
  - strtomem_pad()   for non-NUL-terminated fixed-width fields
  - memcpy_and_pad() for bounded copies with explicit padding
  - memcpy()         for known-length copies

Remove the generic implementation, its declaration, the FORTIFY_SOURCE
wrapper, and associated tests.

Link: https://github.com/KSPP/linux/issues/90 [1]
Signed-off-by: Kees Cook <kees@kernel.org>

Use min() and drop the limit variable to simplify sized_strscpy().

Link: https://lore.kernel.org/20260514165601.527883-3-thorsten.blum@linux.dev
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The call to read_word_at_a_time() in sized_strscpy() is problematic
with MTE because it may trigger a tag check fault when reading
across a tag granule (16 bytes) boundary. To make this code
MTE compatible, let's start using load_unaligned_zeropad()
on architectures where it is available (i.e. architectures that
define CONFIG_DCACHE_WORD_ACCESS). Because load_unaligned_zeropad()
takes care of page boundaries as well as tag granule boundaries,
also disable the code preventing crossing page boundaries when using
load_unaligned_zeropad().

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/If4b22e43b5a4ca49726b4bf98ada827fdf755548
Fixes: 94ab5b61ee16 ("kasan, arm64: enable CONFIG_KASAN_HW_TAGS")
Cc: stable@vger.kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250403000703.2584581-2-pcc@google.com
Signed-off-by: Kees Cook <kees@kernel.org>

The point behind strscpy() was to once and for all avoid all the
problems with 'strncpy()' and later broken "fixed" versions like
strlcpy() that just made things worse.

So strscpy not only guarantees NUL-termination (unlike strncpy), it also
doesn't do unnecessary padding at the destination.  But at the same time
also avoids byte-at-a-time reads and writes by _allowing_ some extra NUL
writes - within the size, of course - so that the whole copy can be done
with word operations.

It is also stable in the face of a mutable source string: it explicitly
does not read the source buffer multiple times (so an implementation
using "strnlen()+memcpy()" would be wrong), and does not read the source
buffer past the size (like the mis-design that is strlcpy does).

Finally, the return value is designed to be simple and unambiguous: if
the string cannot be copied fully, it returns an actual negative error,
making error handling clearer and simpler (and the caller already knows
the size of the buffer).  Otherwise it returns the string length of the
result.

However, there was one final stability issue that can be important to
callers: the stability of the destination buffer.

In particular, the same way we shouldn't read the source buffer more
than once, we should avoid doing multiple writes to the destination
buffer: first writing a potentially non-terminated string, and then
terminating it with NUL at the end does not result in a stable result
buffer.

Yes, it gives the right result in the end, but if the rule for the
destination buffer was that it is _always_ NUL-terminated even when
accessed concurrently with updates, the final byte of the buffer needs
to always _stay_ as a NUL byte.

[ Note that "final byte is NUL" here is literally about the final byte
  in the destination array, not the terminating NUL at the end of the
  string itself. There is no attempt to try to make concurrent reads and
  writes give any kind of consistent string length or contents, but we
  do want to guarantee that there is always at least that final
  terminating NUL character at the end of the destination array if it
  existed before ]

This is relevant in the kernel for the tsk->comm[] array, for example.
Even without locking (for either readers or writers), we want to know
that while the buffer contents may be garbled, it is always a valid C
string and always has a NUL character at 'comm[TASK_COMM_LEN-1]' (and
never has any "out of thin air" data).

So avoid any "copy possibly non-terminated string, and terminate later"
behavior, and write the destination buffer only once.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

Using sizeof(dst) for the "size" argument in strscpy() is the
overwhelmingly common case. Instead of requiring this everywhere, allow a
2-argument version to be used that will use the sizeof() internally. There
are other functions in the kernel with optional arguments[1], so this
isn't unprecedented, and improves readability. Update and relocate the
kern-doc for strscpy() too, and drop __HAVE_ARCH_STRSCPY as it is unused.

Adjust ARCH=um build to notice the changed export name, as it doesn't
do full header includes for the string helpers.

This could additionally let us save a few hundred lines of code:
 1177 files changed, 2455 insertions(+), 3026 deletions(-)
with a treewide cleanup using Coccinelle:

@needless_arg@
expression DST, SRC;
@@

        strscpy(DST, SRC
-, sizeof(DST)
        )

Link: https://elixir.bootlin.com/linux/v6.7/source/include/linux/pci.h#L1517 [1]
Reviewed-by: Justin Stitt <justinstitt@google.com>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

This diff uses an open source tool include-what-you-use (IWYU) to modify
the include list, changing indirect includes to direct includes. IWYU is
implemented using the IWYUScripts github repository which is a tool that
is currently undergoing development. These changes seek to improve build
times.

This change to lib/string.c resulted in a preprocessed size of
lib/string.i from 26371 lines to 5321 lines (-80%) for the x86
defconfig.

Link: https://github.com/ClangBuiltLinux/IWYUScripts
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tanzir Hasan <tanzirh@google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20231226-libstringheader-v6-2-80aa08c7652c@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>

With all the users of strlcpy() removed[1] from the kernel, remove the
API, self-tests, and other references. Leave mentions in Documentation
(about its deprecation), and in checkpatch.pl (to help migrate host-only
tools/ usage). Long live strscpy().

Link: https://github.com/KSPP/linux/issues/89 [1]
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: linux-hardening@vger.kernel.org
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

lib/string.c is built with -ffreestanding, which prevents the compiler
from replacing certain functions with calls to their library versions.

On the other hand, this also prevents Clang and GCC from instrumenting
calls to memcpy() when building with KASAN, KCSAN or KMSAN:
 - KASAN normally replaces memcpy() with __asan_memcpy() with the
   additional cc-param,asan-kernel-mem-intrinsic-prefix=1;
 - KCSAN and KMSAN replace memcpy() with __tsan_memcpy() and
   __msan_memcpy() by default.

To let the tools catch memory accesses from strlcpy/strlcat, replace
the calls to memcpy() with __builtin_memcpy(), which KASAN, KCSAN and
KMSAN are able to replace even in -ffreestanding mode.

This preserves the behavior in normal builds (__builtin_memcpy() ends up
being replaced with memcpy()), and does not introduce new instrumentation
in unwanted places, as strlcpy/strlcat are already instrumented.

Suggested-by: Marco Elver <elver@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/all/20230224085942.1791837-1-elver@google.com/
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230530083911.1104336-1-glider@google.com