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| author | Masahiro Yamada <masahiroy@kernel.org> | 2024-11-07 01:14:41 +0900 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2024-11-27 09:38:27 +0900 |
| commit | dbefa1f31a91670c9e7dac9b559625336206466f (patch) | |
| tree | ed1f7bb74bceef60e8c660d08229881fcd23a9bb /mm | |
| parent | bb43a59944f45e89aa158740b8a16ba8f0b0fa2b (diff) | |
| download | lwn-dbefa1f31a91670c9e7dac9b559625336206466f.tar.gz lwn-dbefa1f31a91670c9e7dac9b559625336206466f.zip | |
Rename .data.once to .data..once to fix resetting WARN*_ONCE
Commit b1fca27d384e ("kernel debug: support resetting WARN*_ONCE")
added support for clearing the state of once warnings. However,
it is not functional when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or
CONFIG_LTO_CLANG is enabled, because .data.once matches the
.data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro.
Commit cb87481ee89d ("kbuild: linker script do not match C names unless
LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress
the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case,
providing a minimal fix for stable backporting. We were aware this did
not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The
plan was to apply correct fixes and then revert cb87481ee89d. [1]
Seven years have passed since then, yet the #ifdef workaround remains in
place. Meanwhile, commit b1fca27d384e introduced the .data.once section,
and commit dc5723b02e52 ("kbuild: add support for Clang LTO") extended
the #ifdef.
Using a ".." separator in the section name fixes the issue for
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG.
[1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/
Fixes: b1fca27d384e ("kernel debug: support resetting WARN*_ONCE")
Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/internal.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/internal.h b/mm/internal.h index 93083bbeeefa..a23f7b11b760 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -48,7 +48,7 @@ struct folio_batch; * when we specify __GFP_NOWARN. */ #define WARN_ON_ONCE_GFP(cond, gfp) ({ \ - static bool __section(".data.once") __warned; \ + static bool __section(".data..once") __warned; \ int __ret_warn_once = !!(cond); \ \ if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \ |