Merge branch 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-alternatives-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, alternatives: BUG on encountering an invalid CPU feature number
  x86, alternatives: Fix one more open-coded 8-bit alternative number
  x86, alternatives: Use 16-bit numbers for cpufeature index
This commit is contained in:
Linus Torvalds 2010-08-06 16:24:17 -07:00
commit 66cd55d2b9
9 changed files with 19 additions and 15 deletions

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@ -45,10 +45,9 @@
struct alt_instr {
u8 *instr; /* original instruction */
u8 *replacement;
u8 cpuid; /* cpuid bit set for replacement */
u16 cpuid; /* cpuid bit set for replacement */
u8 instrlen; /* length of original instruction */
u8 replacementlen; /* length of new instruction, <= instrlen */
u8 pad1;
#ifdef CONFIG_X86_64
u32 pad2;
#endif
@ -86,9 +85,11 @@ static inline int alternatives_text_reserved(void *start, void *end)
_ASM_ALIGN "\n" \
_ASM_PTR "661b\n" /* label */ \
_ASM_PTR "663f\n" /* new instruction */ \
" .byte " __stringify(feature) "\n" /* feature bit */ \
" .word " __stringify(feature) "\n" /* feature bit */ \
" .byte 662b-661b\n" /* sourcelen */ \
" .byte 664f-663f\n" /* replacementlen */ \
".previous\n" \
".section .discard,\"aw\",@progbits\n" \
" .byte 0xff + (664f-663f) - (662b-661b)\n" /* rlen <= slen */ \
".previous\n" \
".section .altinstr_replacement, \"ax\"\n" \

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@ -302,7 +302,7 @@ extern const char * const x86_power_flags[32];
* patch the target code for additional performance.
*
*/
static __always_inline __pure bool __static_cpu_has(u8 bit)
static __always_inline __pure bool __static_cpu_has(u16 bit)
{
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
asm goto("1: jmp %l[t_no]\n"
@ -311,11 +311,11 @@ static __always_inline __pure bool __static_cpu_has(u8 bit)
_ASM_ALIGN "\n"
_ASM_PTR "1b\n"
_ASM_PTR "0\n" /* no replacement */
" .byte %P0\n" /* feature bit */
" .word %P0\n" /* feature bit */
" .byte 2b - 1b\n" /* source len */
" .byte 0\n" /* replacement len */
" .byte 0xff + 0 - (2b-1b)\n" /* padding */
".previous\n"
/* skipping size check since replacement size = 0 */
: : "i" (bit) : : t_no);
return true;
t_no:
@ -329,10 +329,12 @@ static __always_inline __pure bool __static_cpu_has(u8 bit)
_ASM_ALIGN "\n"
_ASM_PTR "1b\n"
_ASM_PTR "3f\n"
" .byte %P1\n" /* feature bit */
" .word %P1\n" /* feature bit */
" .byte 2b - 1b\n" /* source len */
" .byte 4f - 3f\n" /* replacement len */
" .byte 0xff + (4f-3f) - (2b-1b)\n" /* padding */
".previous\n"
".section .discard,\"aw\",@progbits\n"
" .byte 0xff + (4f-3f) - (2b-1b)\n" /* size check */
".previous\n"
".section .altinstr_replacement,\"ax\"\n"
"3: movb $1,%0\n"
@ -348,7 +350,7 @@ static __always_inline __pure bool __static_cpu_has(u8 bit)
( \
__builtin_constant_p(boot_cpu_has(bit)) ? \
boot_cpu_has(bit) : \
(__builtin_constant_p(bit) && !((bit) & ~0xff)) ? \
__builtin_constant_p(bit) ? \
__static_cpu_has(bit) : \
boot_cpu_has(bit) \
)

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@ -214,6 +214,7 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
u8 *instr = a->instr;
BUG_ON(a->replacementlen > a->instrlen);
BUG_ON(a->instrlen > sizeof(insnbuf));
BUG_ON(a->cpuid >= NCAPINTS*32);
if (!boot_cpu_has(a->cpuid))
continue;
#ifdef CONFIG_X86_64

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@ -913,7 +913,7 @@ ENTRY(simd_coprocessor_error)
.balign 4
.long 661b
.long 663f
.byte X86_FEATURE_XMM
.word X86_FEATURE_XMM
.byte 662b-661b
.byte 664f-663f
.previous

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@ -52,7 +52,7 @@ ENDPROC(clear_page)
.align 8
.quad clear_page
.quad 1b
.byte X86_FEATURE_REP_GOOD
.word X86_FEATURE_REP_GOOD
.byte .Lclear_page_end - clear_page
.byte 2b - 1b
.previous

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@ -113,7 +113,7 @@ ENDPROC(copy_page)
.align 8
.quad copy_page
.quad 1b
.byte X86_FEATURE_REP_GOOD
.word X86_FEATURE_REP_GOOD
.byte .Lcopy_page_end - copy_page
.byte 2b - 1b
.previous

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@ -29,7 +29,7 @@
.align 8
.quad 0b
.quad 2b
.byte \feature /* when feature is set */
.word \feature /* when feature is set */
.byte 5
.byte 5
.previous

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@ -131,7 +131,7 @@ ENDPROC(__memcpy)
.align 8
.quad memcpy
.quad .Lmemcpy_c
.byte X86_FEATURE_REP_GOOD
.word X86_FEATURE_REP_GOOD
/*
* Replace only beginning, memcpy is used to apply alternatives,

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@ -121,7 +121,7 @@ ENDPROC(__memset)
.align 8
.quad memset
.quad .Lmemset_c
.byte X86_FEATURE_REP_GOOD
.word X86_FEATURE_REP_GOOD
.byte .Lfinal - memset
.byte .Lmemset_e - .Lmemset_c
.previous