diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/string.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/lib/string.c b/lib/string.c index ae7835f600..73b984123d 100644 --- a/lib/string.c +++ b/lib/string.c @@ -567,7 +567,19 @@ void * memmove(void * dest,const void *src,size_t count) { char *tmp, *s; - if (dest <= src) { + if (dest <= src || (src + count) <= dest) { + /* + * Use the fast memcpy implementation (ARCH optimized or lib/string.c) when it is possible: + * - when dest is before src (assuming that memcpy is doing forward-copying) + * - when destination don't overlap the source buffer (src + count <= dest) + * + * WARNING: the first optimisation cause an issue, when __HAVE_ARCH_MEMCPY is defined, + * __HAVE_ARCH_MEMMOVE is not defined and if the memcpy ARCH-specific + * implementation is not doing a forward-copying. + * + * No issue today because memcpy is doing a forward-copying in lib/string.c and for ARM32 + * architecture; no other arches use __HAVE_ARCH_MEMCPY without __HAVE_ARCH_MEMMOVE. + */ memcpy(dest, src, count); } else { tmp = (char *) dest + count; |