linux.git/tools/include/linux/bits.h, branch v6.18.21

tools headers: Sync linux/bits.h with the kernel source

2025-08-18T19:38:42+00:00

To pick up the changes in this cset:

  104ea1c84b91c9f4 bits: unify the non-asm GENMASK*()
  6d4471252ccc1722 bits: split the definition of the asm and non-asm GENMASK*()

This addresses these perf build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/linux/bits.h include/linux/bits.h

Please see tools/include/uapi/README for further details.

Cc: Yury Norov 
Signed-off-by: Namhyung Kim

tools headers: Synchronize linux/bits.h with the kernel sources

2025-06-17T19:55:24+00:00

To pick up the changes in this cset:

  1e7933a575ed8af4 ("uapi: Revert "bitops: avoid integer overflow in GENMASK(_ULL)"")
  5b572e8a9f3dcd6e ("bits: introduce fixed-type BIT_U*()")
  19408200c094858d ("bits: introduce fixed-type GENMASK_U*()")
  31299a5e02112411 ("bits: add comments and newlines to #if, #else and #endif directives")

This addresses these perf build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/linux/bits.h include/linux/bits.h

Please see tools/include/uapi/README for further details.

Acked-by: Vincent Mailhol 
Cc: I Hsin Cheng 
Cc: Yury Norov 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Lucas De Marchi 
Cc: Namhyung Kim 
Cc: Yury Norov 
Link: https://lore.kernel.org/r/aEr0ZJ60EbshEy6p@x1
Signed-off-by: Arnaldo Carvalho de Melo

tools headers: Synchronize linux/bits.h with the kernel sources

2025-05-20T15:57:19+00:00

To pick up the changes in this cset:

  0312e94abe484b9e ("treewide: fix typo 'unsigned __init128' -> 'unsigned __int128'")

This addresses these perf build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/linux/bits.h include/linux/bits.h

This required picking the const_true() define in linux/compiler.h as a
prep patch as that macro is used in the new linux/bits.h

Please see tools/include/uapi/README for further details.

Acked-by: Vincent Mailhol 
Acked-by: Yury Norov [NVIDIA] 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/r/20250519214126.1652491-8-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

treewide: fix typo 'unsigned init128' -> 'unsigned int128'

2025-03-05T17:00:03+00:00

"int" was misspelled as "init" the code comments in the bits.h and
const.h files. Fix the typo.

CC: Andy Shevchenko 
Signed-off-by: Vincent Mailhol 
Signed-off-by: Yury Norov

tools headers: Synchronize {uapi/}linux/bits.h with the kernel sources

2024-10-28T15:32:25+00:00

To pick up the changes in this cset:

  947697c6f0f75f98 ("uapi: Define GENMASK_U128")

This addresses these perf build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/uapi/linux/bits.h include/uapi/linux/bits.h
    diff -u tools/include/linux/bits.h include/linux/bits.h

Please see tools/include/uapi/README for further details.

Acked-by: Yury Norov 
Cc: Adrian Hunter 
Cc: Anshuman Khandual 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/lkml/Zx-ZVH7bHqtFn8Dv@x1
Signed-off-by: Arnaldo Carvalho de Melo

tools headers: Synchronize linux/bits.h with the kernel sources

2024-04-27T01:13:10+00:00

To pick up the changes in this cset:

   3c7a8e190bc58081 ("uapi: introduce uapi-friendly macros for GENMASK")

That just causes perf to rebuild. Its just some macros going to an uapi
header that we now have to grab a copy into tools/ as well.

This addresses this perf build warning:

  Warning: Kernel ABI header differences:
    diff -u tools/include/linux/bits.h include/linux/bits.h

Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Cc: Paolo Bonzini 
Link: https://lore.kernel.org/lkml/ZiwJsFOBez0MS4r9@x1
Signed-off-by: Arnaldo Carvalho de Melo

tools headers: Synchronize {linux,vdso}/bits.h with the kernel sources

2023-03-04T01:34:15+00:00

To pick up the changes in this cset:

  cbdb1f163af2bb90 ("vdso/bits.h: Add BIT_ULL() for the sake of consistency")

That just causes perf to rebuild, the macro included doesn't clash with
anything in tools/{perf,objtool,bpf}.

This addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/include/linux/bits.h' differs from latest version at 'include/linux/bits.h'
  diff -u tools/include/linux/bits.h include/linux/bits.h
  Warning: Kernel ABI header at 'tools/include/vdso/bits.h' differs from latest version at 'include/vdso/bits.h'
  diff -u tools/include/vdso/bits.h include/vdso/bits.h

Signed-off-by: Arnaldo Carvalho de Melo

linux/bits.h: fix compilation error with GENMASK

2021-05-23T01:09:07+00:00

GENMASK() has an input check which uses __builtin_choose_expr() to
enable a compile time sanity check of its inputs if they are known at
compile time.

However, it turns out that __builtin_constant_p() does not always return
a compile time constant [0].  It was thought this problem was fixed with
gcc 4.9 [1], but apparently this is not the case [2].

Switch to use __is_constexpr() instead which always returns a compile time
constant, regardless of its inputs.

Link: https://lore.kernel.org/lkml/42b4342b-aefc-a16a-0d43-9f9c0d63ba7a@rasmusvillemoes.dk [0]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19449 [1]
Link: https://lore.kernel.org/lkml/1ac7bbc2-45d9-26ed-0b33-bf382b8d858b@I-love.SAKURA.ne.jp [2]
Link: https://lkml.kernel.org/r/20210511203716.117010-1-rikard.falkeborn@gmail.com
Signed-off-by: Rikard Falkeborn 
Reported-by: Tetsuo Handa 
Acked-by: Arnd Bergmann 
Reviewed-by: Andy Shevchenko 
Cc: Ard Biesheuvel 
Cc: Yury Norov 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Raise gcc version requirement to 4.9

2020-07-08T17:48:35+00:00

I realize that we fairly recently raised it to 4.8, but the fact is, 4.9
is a much better minimum version to target.

We have a number of workarounds for actual bugs in pre-4.9 gcc versions
(including things like internal compiler errors on ARM), but we also
have some syntactic workarounds for lacking features.

In particular, raising the minimum to 4.9 means that we can now just
assume _Generic() exists, which is likely the much better replacement
for a lot of very convoluted built-time magic with conditionals on
sizeof and/or __builtin_choose_expr() with same_type() etc.

Using _Generic also means that you will need to have a very recent
version of 'sparse', but thats easy to build yourself, and much less of
a hassle than some old gcc version can be.

The latest (in a long string) of reasons for minimum compiler version
upgrades was commit 5435f73d5c4a ("efi/x86: Fix build with gcc 4").

Ard points out that RHEL 7 uses gcc-4.8, but the people who stay back on
old RHEL versions persumably also don't build their own kernels anyway.
And maybe they should cross-built or just have a little side affair with
a newer compiler?

Acked-by: Ard Biesheuvel 
Acked-by: Peter Zijlstra 
Signed-off-by: Linus Torvalds

tools headers: Synchronize linux/bits.h with the kernel sources

2020-04-14T14:40:05+00:00

To pick up the changes in these csets:

  295bcca84916 ("linux/bits.h: add compile time sanity check of GENMASK inputs")
  3945ff37d2f4 ("linux/bits.h: Extract common header for vDSO")

To address this tools/perf build warning:

  Warning: Kernel ABI header at 'tools/include/linux/bits.h' differs from latest version at 'include/linux/bits.h'
  diff -u tools/include/linux/bits.h include/linux/bits.h

This clashes with usage of userspace's static_assert(), that, at least
on glibc, is guarded by a ifnded/endif pair, do the same to our copy of
build_bug.h and avoid that diff in check_headers.sh so that we continue
checking for drifts with the kernel sources master copy.

This will all be tested with the set of build containers that includes
uCLibc, musl libc, lots of glibc versions in lots of distros and cross
build environments.

The tools/objtool, tools/bpf, etc were tested as well.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Rikard Falkeborn 
Cc: Thomas Gleixner 
Cc: Vincenzo Frascino 
Signed-off-by: Arnaldo Carvalho de Melo