Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-22 12:11:40 +00:00
Code Issues Packages Projects Releases Wiki Activity

x86/alternative: Convert ALTERNATIVE_3()

Browse Source 
Zap the hack of using an ALTERNATIVE_3() internal label, as suggested by
bgerst:

  https://lore.kernel.org/r/CAMzpN2i4oJ-Dv0qO46Fd-DxNv5z9=x%2BvO%2B8g=47NiiAf8QEJYA@mail.gmail.com

in favor of a label local to this macro only, as it should be done.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240607111701.8366-11-bp@kernel.org
This commit is contained in:
Borislav Petkov (AMD) 2024-06-07 13:16:57 +02:00
parent d2d302b1bb
commit 93694129c6
2 changed files with 9 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
arch/x86/include/asm/alternative.h
View File

@ -277,26 +277,10 @@ static inline int alternatives_text_reserved(void *start, void *end)
N_ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \
newinstr_yes, ft_flags)
#define ALTERNATIVE_3(oldinsn, newinsn1, ft_flags1, newinsn2, ft_flags2, \
newinsn3, ft_flags3) \
OLDINSTR_3(oldinsn, 1, 2, 3) \
".pushsection .altinstructions,\"a\"\n" \
ALTINSTR_ENTRY(ft_flags1, 1) \
ALTINSTR_ENTRY(ft_flags2, 2) \
ALTINSTR_ENTRY(ft_flags3, 3) \
".popsection\n" \
".pushsection .altinstr_replacement, \"ax\"\n" \
ALTINSTR_REPLACEMENT(newinsn1, 1) \
ALTINSTR_REPLACEMENT(newinsn2, 2) \
ALTINSTR_REPLACEMENT(newinsn3, 3) \
".popsection\n"
#define N_ALTERNATIVE_3(oldinst, newinst1, flag1, newinst2, flag2, \
newinst3, flag3) \
N_ALTERNATIVE(N_ALTERNATIVE_2(oldinst, newinst1, flag1, newinst2, flag2), \
newinst3, flag3)
#define ALTERNATIVE_3(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2, \
newinstr3, ft_flags3) \
N_ALTERNATIVE(N_ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2), \
newinstr3, ft_flags3)
/*
* Alternative instructions for different CPU types or capabilities.
*

14
arch/x86/kernel/fpu/xstate.h
View File

@ -106,21 +106,17 @@ static inline u64 xfeatures_mask_independent(void)
* Otherwise, if XSAVEOPT is enabled, XSAVEOPT replaces XSAVE because XSAVEOPT
* supports modified optimization which is not supported by XSAVE.
*
* We use XSAVE as a fallback.
*
* The 661 label is defined in the ALTERNATIVE* macros as the address of the
* original instruction which gets replaced. We need to use it here as the
* address of the instruction where we might get an exception at.
* Use XSAVE as a fallback.
*/
#define XSTATE_XSAVE(st, lmask, hmask, err) \
asm volatile(ALTERNATIVE_3(XSAVE, \
asm volatile("1: " ALTERNATIVE_3(XSAVE, \
XSAVEOPT, X86_FEATURE_XSAVEOPT, \
XSAVEC, X86_FEATURE_XSAVEC, \
XSAVES, X86_FEATURE_XSAVES) \
"\n" \
"xor %[err], %[err]\n" \
"3:\n" \
_ASM_EXTABLE_TYPE_REG(661b, 3b, EX_TYPE_EFAULT_REG, %[err]) \
_ASM_EXTABLE_TYPE_REG(1b, 3b, EX_TYPE_EFAULT_REG, %[err]) \
: [err] "=r" (err) \
: "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \
: "memory")
@ -130,11 +126,11 @@ static inline u64 xfeatures_mask_independent(void)
* XSAVE area format.
*/
#define XSTATE_XRESTORE(st, lmask, hmask) \
asm volatile(ALTERNATIVE(XRSTOR, \
asm volatile("1: " ALTERNATIVE(XRSTOR, \
XRSTORS, X86_FEATURE_XSAVES) \
"\n" \
"3:\n" \
_ASM_EXTABLE_TYPE(661b, 3b, EX_TYPE_FPU_RESTORE) \
_ASM_EXTABLE_TYPE(1b, 3b, EX_TYPE_FPU_RESTORE) \
: \
: "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \
: "memory")