diff options
| -rw-r--r-- | arch/x86/boot/compressed/string.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/boot/compressed/string.c b/arch/x86/boot/compressed/string.c index faa4dc7dc66b..cea140ce6b42 100644 --- a/arch/x86/boot/compressed/string.c +++ b/arch/x86/boot/compressed/string.c @@ -10,7 +10,7 @@ #include "../string.c" #ifdef CONFIG_X86_32 -void *memcpy(void *dest, const void *src, size_t n) +static void *__memcpy(void *dest, const void *src, size_t n) { int d0, d1, d2; asm volatile( @@ -24,7 +24,7 @@ void *memcpy(void *dest, const void *src, size_t n) return dest; } #else -void *memcpy(void *dest, const void *src, size_t n) +static void *__memcpy(void *dest, const void *src, size_t n) { long d0, d1, d2; asm volatile( @@ -55,10 +55,20 @@ void *memmove(void *dest, const void *src, size_t n) const unsigned char *s = src; if (d <= s || d - s >= n) - return memcpy(dest, src, n); + return __memcpy(dest, src, n); while (n-- > 0) d[n] = s[n]; return dest; } + +/* Detect and warn about potential overlaps, but handle them with memmove. */ +void *memcpy(void *dest, const void *src, size_t n) +{ + if (dest > src && dest - src < n) { + warn("Avoiding potentially unsafe overlapping memcpy()!"); + return memmove(dest, src, n); + } + return __memcpy(dest, src, n); +} |