mirror of
https://github.com/torvalds/linux.git
synced 2024-12-27 13:22:23 +00:00
cbf8b5a2b6
Returning a 'bool' was very unpopular. Doubly so because the
code was just wrong (returning zero for true, one for false;
great for shell programming, not so good for C).
Change return type to "int". Keep zero as the success indicator
because it matches other similar code and people may be more
comfortable writing:
if (memcpy_mcsafe(to, from, count)) {
printk("Sad panda, copy failed\n");
...
}
Make the failure return value -EFAULT for now.
Reported by: Mika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mika.penttila@nextfour.com
Fixes: 92b0729c34 ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Link: http://lkml.kernel.org/r/695f14233fa7a54fcac4406c706d7fec228e3f4c.1457993040.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
97 lines
2.6 KiB
C
97 lines
2.6 KiB
C
#ifndef _ASM_X86_STRING_64_H
|
|
#define _ASM_X86_STRING_64_H
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
/* Written 2002 by Andi Kleen */
|
|
|
|
/* Only used for special circumstances. Stolen from i386/string.h */
|
|
static __always_inline void *__inline_memcpy(void *to, const void *from, size_t n)
|
|
{
|
|
unsigned long d0, d1, d2;
|
|
asm volatile("rep ; movsl\n\t"
|
|
"testb $2,%b4\n\t"
|
|
"je 1f\n\t"
|
|
"movsw\n"
|
|
"1:\ttestb $1,%b4\n\t"
|
|
"je 2f\n\t"
|
|
"movsb\n"
|
|
"2:"
|
|
: "=&c" (d0), "=&D" (d1), "=&S" (d2)
|
|
: "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
|
|
: "memory");
|
|
return to;
|
|
}
|
|
|
|
/* Even with __builtin_ the compiler may decide to use the out of line
|
|
function. */
|
|
|
|
#define __HAVE_ARCH_MEMCPY 1
|
|
extern void *memcpy(void *to, const void *from, size_t len);
|
|
extern void *__memcpy(void *to, const void *from, size_t len);
|
|
|
|
#ifndef CONFIG_KMEMCHECK
|
|
#if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4
|
|
#define memcpy(dst, src, len) \
|
|
({ \
|
|
size_t __len = (len); \
|
|
void *__ret; \
|
|
if (__builtin_constant_p(len) && __len >= 64) \
|
|
__ret = __memcpy((dst), (src), __len); \
|
|
else \
|
|
__ret = __builtin_memcpy((dst), (src), __len); \
|
|
__ret; \
|
|
})
|
|
#endif
|
|
#else
|
|
/*
|
|
* kmemcheck becomes very happy if we use the REP instructions unconditionally,
|
|
* because it means that we know both memory operands in advance.
|
|
*/
|
|
#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
|
|
#endif
|
|
|
|
#define __HAVE_ARCH_MEMSET
|
|
void *memset(void *s, int c, size_t n);
|
|
void *__memset(void *s, int c, size_t n);
|
|
|
|
#define __HAVE_ARCH_MEMMOVE
|
|
void *memmove(void *dest, const void *src, size_t count);
|
|
void *__memmove(void *dest, const void *src, size_t count);
|
|
|
|
int memcmp(const void *cs, const void *ct, size_t count);
|
|
size_t strlen(const char *s);
|
|
char *strcpy(char *dest, const char *src);
|
|
char *strcat(char *dest, const char *src);
|
|
int strcmp(const char *cs, const char *ct);
|
|
|
|
#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
|
|
|
|
/*
|
|
* For files that not instrumented (e.g. mm/slub.c) we
|
|
* should use not instrumented version of mem* functions.
|
|
*/
|
|
|
|
#undef memcpy
|
|
#define memcpy(dst, src, len) __memcpy(dst, src, len)
|
|
#define memmove(dst, src, len) __memmove(dst, src, len)
|
|
#define memset(s, c, n) __memset(s, c, n)
|
|
#endif
|
|
|
|
/**
|
|
* memcpy_mcsafe - copy memory with indication if a machine check happened
|
|
*
|
|
* @dst: destination address
|
|
* @src: source address
|
|
* @cnt: number of bytes to copy
|
|
*
|
|
* Low level memory copy function that catches machine checks
|
|
*
|
|
* Return 0 for success, -EFAULT for fail
|
|
*/
|
|
int memcpy_mcsafe(void *dst, const void *src, size_t cnt);
|
|
|
|
#endif /* __KERNEL__ */
|
|
|
|
#endif /* _ASM_X86_STRING_64_H */
|