Messages in this thread Patch in this message | | | From | Christophe Leroy <> | Subject | [PATCH 6/7] powerpc/lib: inline more NUL size verifications | Date | Tue, 17 Apr 2018 09:38:45 +0200 (CEST) |
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strncmp(), strncpy(), memchr() are often called with constant size.
This patch gives GCC a chance to optimise NULL size verification out
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/include/asm/string.h | 24 ++++++++++++++++++++++++ arch/powerpc/lib/string.S | 8 ++++++++ 2 files changed, 32 insertions(+)
diff --git a/arch/powerpc/include/asm/string.h b/arch/powerpc/include/asm/string.h index 196ac5d587fb..1465d5629ef2 100644 --- a/arch/powerpc/include/asm/string.h +++ b/arch/powerpc/include/asm/string.h @@ -30,6 +30,22 @@ extern void * memchr(const void *,int,__kernel_size_t); extern void * memcpy_flushcache(void *,const void *,__kernel_size_t); #ifndef CONFIG_FORTIFY_SOURCE +static inline char *__strncpy(char *p, const char *q, __kernel_size_t size) +{ + if (unlikely(!size)) + return p; + return strncpy(p, q, size); +} +#define strncpy __strncpy + +static inline int __strncmp(const char *p, const char *q, __kernel_size_t size) +{ + if (unlikely(!size)) + return 0; + return strncmp(p, q, size); +} +#define strncmp __strncmp + static inline int ___memcmp(const void *p,const void *q,__kernel_size_t size, int offset) { int dif; @@ -72,6 +88,14 @@ static inline int __memcmp(const void *p,const void *q,__kernel_size_t size) return memcmp(p, q, size); } #define memcmp __memcmp + +static inline void *__memchr(const void *p, int c, __kernel_size_t size) +{ + if (unlikely(!size)) + return NULL; + return memchr(p, c, size); +} +#define memchr __memchr #endif #ifdef CONFIG_PPC64 diff --git a/arch/powerpc/lib/string.S b/arch/powerpc/lib/string.S index cbb90fdc672d..89af53b08b4a 100644 --- a/arch/powerpc/lib/string.S +++ b/arch/powerpc/lib/string.S @@ -18,8 +18,10 @@ /* This clears out any unused part of the destination buffer, just as the libc version does. -- paulus */ _GLOBAL(strncpy) +#ifdef CONFIG_FORTIFY_SOURCE PPC_LCMPI 0,r5,0 beqlr +#endif mtctr r5 addi r6,r3,-1 addi r4,r4,-1 @@ -38,8 +40,10 @@ _GLOBAL(strncpy) EXPORT_SYMBOL(strncpy) _GLOBAL(strncmp) +#ifdef CONFIG_FORTIFY_SOURCE PPC_LCMPI 0,r5,0 beq- 2f +#endif mtctr r5 addi r5,r3,-1 addi r4,r4,-1 @@ -51,13 +55,17 @@ _GLOBAL(strncmp) beqlr 1 bdnzt eq,1b blr +#ifdef CONFIG_FORTIFY_SOURCE 2: li r3,0 blr +#endif EXPORT_SYMBOL(strncmp) _GLOBAL(memchr) +#ifdef CONFIG_FORTIFY_SOURCE PPC_LCMPI 0,r5,0 beq- 2f +#endif mtctr r5 addi r3,r3,-1 .balign 16 -- 2.13.3
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