diff options
| author | Rich Felker <dalias@aerifal.cx> | 2018-09-26 14:39:10 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2018-09-26 14:39:10 -0400 |
| commit | 4d0a82170a25464c39522d7190b9fe302045ddb2 (patch) | |
| tree | b3a469567ed3a995300c9751b824ef20b84f154d /src/string/strchrnul.c | |
| parent | 8cd738bbee3b4e60a99b71599c338bf444070f18 (diff) | |
| download | musl-4d0a82170a25464c39522d7190b9fe302045ddb2.tar.gz | |
fix aliasing-based undefined behavior in string functions
use the GNU C may_alias attribute if available, and fallback to naive
byte-by-byte loops if __GNUC__ is not defined.
this patch has been written to minimize changes so that history
remains reviewable; it does not attempt to bring the affected code
into a more consistent or elegant form.
Diffstat (limited to 'src/string/strchrnul.c')
| -rw-r--r-- | src/string/strchrnul.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/string/strchrnul.c b/src/string/strchrnul.c index f2b9ae11..39e2635b 100644 --- a/src/string/strchrnul.c +++ b/src/string/strchrnul.c @@ -9,16 +9,19 @@ char *__strchrnul(const char *s, int c) { - size_t *w, k; - c = (unsigned char)c; if (!c) return (char *)s + strlen(s); +#ifdef __GNUC__ + typedef size_t __attribute__((__may_alias__)) word; + const word *w; for (; (uintptr_t)s % ALIGN; s++) if (!*s || *(unsigned char *)s == c) return (char *)s; - k = ONES * c; + size_t k = ONES * c; for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w^k); w++); - for (s = (void *)w; *s && *(unsigned char *)s != c; s++); + s = (void *)w; +#endif + for (; *s && *(unsigned char *)s != c; s++); return (char *)s; } |