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| author | Peter Zijlstra <peterz@infradead.org> | 2024-03-13 13:42:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-10 17:18:49 +0300 |
| commit | ab8f581408c526319fefbd9db323d43b4342a5fc (patch) | |
| tree | 6cbe770cc65dec9d2ecee432940690e284d7fc35 /include | |
| parent | 2ae88e83f3b7e579a7085d140f61122f128932f1 (diff) | |
| download | linux-ab8f581408c526319fefbd9db323d43b4342a5fc.tar.xz | |
arch: Introduce CONFIG_FUNCTION_ALIGNMENT
commit d49a0626216b95cd4bf696f6acf55f39a16ab0bb upstream.
Generic function-alignment infrastructure.
Architectures can select FUNCTION_ALIGNMENT_xxB symbols; the
FUNCTION_ALIGNMENT symbol is then set to the largest such selected
size, 0 otherwise.
>From this the -falign-functions compiler argument and __ALIGN macro
are set.
This incorporates the DEBUG_FORCE_FUNCTION_ALIGN_64B knob and future
alignment requirements for x86_64 (later in this series) into a single
place.
NOTE: also removes the 0x90 filler byte from the generic __ALIGN
primitive, that value makes no sense outside of x86.
NOTE: .balign 0 reverts to a no-op.
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I053b3c408d56988381feb8c8bdb5e27ea221755f
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111143.719248727@infradead.org
[cascardo: adjust context at arch/x86/Kconfig]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 4 | ||||
| -rw-r--r-- | include/linux/linkage.h | 4 |
2 files changed, 4 insertions, 4 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 8471717c5085..dd9ea351bc02 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -81,8 +81,8 @@ #define RO_EXCEPTION_TABLE #endif -/* Align . to a 8 byte boundary equals to maximum function alignment. */ -#define ALIGN_FUNCTION() . = ALIGN(8) +/* Align . function alignment. */ +#define ALIGN_FUNCTION() . = ALIGN(CONFIG_FUNCTION_ALIGNMENT) /* * LD_DEAD_CODE_DATA_ELIMINATION option enables -fdata-sections, which diff --git a/include/linux/linkage.h b/include/linux/linkage.h index dbf8506decca..fc81e51330b2 100644 --- a/include/linux/linkage.h +++ b/include/linux/linkage.h @@ -69,8 +69,8 @@ #endif #ifndef __ALIGN -#define __ALIGN .align 4,0x90 -#define __ALIGN_STR ".align 4,0x90" +#define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT +#define __ALIGN_STR __stringify(__ALIGN) #endif #ifdef __ASSEMBLY__ |