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x86/asm: Differentiate between code and function alignment

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commit 8eb5d34e77c63fde8af21c691bcf6e3cd87f7829 upstream.

Create SYM_F_ALIGN to differentiate alignment requirements between
SYM_CODE and SYM_FUNC.

This distinction is useful later when adding padding in front of
functions; IOW this allows following the compiler's
patchable-function-entry option.

[peterz: Changelog]

Change-Id: I4f9bc0507e5c3fdb3e0839806989efc305e0a758
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111143.824822743@infradead.org
[cascardo: adjust for missing commit c4691712b546 ("x86/linkage: Add ENDBR to SYM_FUNC_START*()")]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thomas Gleixner 2024-03-13 07:42:52 -03:00 committed by Greg Kroah-Hartman
parent ab8f581408
commit 9b4eff016d
1 changed files with 6 additions and 2 deletions
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8
arch/x86/include/asm/linkage.h
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@ -11,11 +11,15 @@
#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
#endif /* CONFIG_X86_32 */
#ifdef __ASSEMBLY__
#define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT, 0x90;
#define __ALIGN_STR __stringify(__ALIGN)
#define ASM_FUNC_ALIGN __ALIGN_STR
#define __FUNC_ALIGN __ALIGN
#define SYM_F_ALIGN __FUNC_ALIGN
#ifdef __ASSEMBLY__
#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define RET jmp __x86_return_thunk
#else /* CONFIG_RETPOLINE */