diff options
| -rw-r--r-- | payloads/libpayload/libc/memory.c | 63 |
1 files changed, 40 insertions, 23 deletions
diff --git a/payloads/libpayload/libc/memory.c b/payloads/libpayload/libc/memory.c index 12d7e33dfd..aec60e4eb8 100644 --- a/payloads/libpayload/libc/memory.c +++ b/payloads/libpayload/libc/memory.c @@ -35,12 +35,22 @@ static void *default_memset(void *s, int c, size_t n) { - char *os = s; + size_t i; + void *ret = s; + unsigned long w = c & 0xff; - while (n--) - *(os++) = c; + for (i = 1; i < sizeof(unsigned long); i <<= 1) + w = (w << (i * 8)) | w; - return s; + for (i = 0; i < n / sizeof(unsigned long); i++) + ((unsigned long *)s)[i] = w; + + s += i * sizeof(unsigned long); + + for (i = 0; i < n % sizeof(unsigned long); i++) + ((u8 *)s)[i] = (u8)c; + + return ret; } void *memset(void *s, int c, size_t n) @@ -48,18 +58,17 @@ void *memset(void *s, int c, size_t n) static void *default_memcpy(void *dst, const void *src, size_t n) { - int i; + size_t i; void *ret = dst; - for(i = 0; i < n % sizeof(unsigned long); i++) - ((unsigned char *) dst)[i] = ((unsigned char *) src)[i]; + for(i = 0; i < n / sizeof(unsigned long); i++) + ((unsigned long *)dst)[i] = ((unsigned long *)src)[i]; - n -= i; - src += i; - dst += i; + src += i * sizeof(unsigned long); + dst += i * sizeof(unsigned long); - for(i = 0; i < n / sizeof(unsigned long); i++) - ((unsigned long *) dst)[i] = ((unsigned long *) src)[i]; + for(i = 0; i < n % sizeof(unsigned long); i++) + ((u8 *)dst)[i] = ((u8 *)src)[i]; return ret; } @@ -69,8 +78,7 @@ void *memcpy(void *dst, const void *src, size_t n) static void *default_memmove(void *dst, const void *src, size_t n) { - int i; - unsigned long offs; + size_t i, offs; if (src > dst) return memcpy(dst, src, n); @@ -78,8 +86,7 @@ static void *default_memmove(void *dst, const void *src, size_t n) offs = n - (n % sizeof(unsigned long)); for (i = (n % sizeof(unsigned long)) - 1; i >= 0; i--) - ((unsigned char *)dst)[i + offs] = - ((unsigned char *)src)[i + offs]; + ((u8 *)dst)[i + offs] = ((u8 *)src)[i + offs]; for (i = n / sizeof(unsigned long) - 1; i >= 0; i--) ((unsigned long *)dst)[i] = ((unsigned long *)src)[i]; @@ -95,17 +102,27 @@ void *memmove(void *dst, const void *src, size_t n) * * @param s1 Pointer to the first area to compare. * @param s2 Pointer to the second area to compare. - * @param len Size of the first area in bytes (both must have the same length). - * @return If len is 0, return zero. If the areas match, return zero. - * Otherwise return non-zero. + * @param n Size of the first area in bytes (both must have the same length). + * @return If n is 0, return zero. Otherwise, return a value less than, equal + * to, or greater than zero if s1 is found less than, equal to, or + * greater than s2 respectively. */ -static int default_memcmp(const void *s1, const void *s2, size_t len) +static int default_memcmp(const void *s1, const void *s2, size_t n) { - for (; len && *(char *)s1++ == *(char *)s2++; len--) ; - return len; + size_t i; + + for (i = 0; i < n / sizeof(unsigned long); i++) + if (((unsigned long *)s1)[i] != ((unsigned long *)s2)[i]) + break; /* fall through to find differing byte */ + + for (i *= sizeof(unsigned long); i < n; i++) + if (((u8 *)s1)[i] != ((u8 *)s2)[i]) + return ((u8 *)s1)[i] - ((u8 *)s2)[i]; + + return 0; } -int memcmp(const void *s1, const void *s2, size_t len) +int memcmp(const void *s1, const void *s2, size_t n) __attribute__((weak, alias("default_memcmp"))); |