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| author | Peter Zijlstra <peterz@infradead.org> | 2022-09-15 13:10:47 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-10-17 16:40:58 +0200 |
| commit | d49a0626216b95cd4bf696f6acf55f39a16ab0bb (patch) | |
| tree | 52349000d2ed416b132b74e58c9f005b9a51211c /arch/x86/boot | |
| parent | 24a9c543d2114d416f84e386c2fa90089bd97e4c (diff) | |
| download | linux-d49a0626216b95cd4bf696f6acf55f39a16ab0bb.tar.bz2 | |
arch: Introduce CONFIG_FUNCTION_ALIGNMENT
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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111143.719248727@infradead.org
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index d33f060900d2..190b803eb787 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -38,6 +38,14 @@ #include "pgtable.h" /* + * Fix alignment at 16 bytes. Following CONFIG_FUNCTION_ALIGNMENT will result + * in assembly errors due to trying to move .org backward due to the excessive + * alignment. + */ +#undef __ALIGN +#define __ALIGN .balign 16, 0x90 + +/* * Locally defined symbols should be marked hidden: */ .hidden _bss |