diff options
| -rw-r--r-- | lib/libc/uuid/uuid_compare.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/lib/libc/uuid/uuid_compare.c b/lib/libc/uuid/uuid_compare.c index f57a094..420f326 100644 --- a/lib/libc/uuid/uuid_compare.c +++ b/lib/libc/uuid/uuid_compare.c @@ -41,7 +41,8 @@ int32_t uuid_compare(const uuid_t *a, const uuid_t *b, uint32_t *status) { - int res; + int res; + int64_t res64; if (status != NULL) *status = uuid_s_ok; @@ -54,10 +55,19 @@ uuid_compare(const uuid_t *a, const uuid_t *b, uint32_t *status) if (b == NULL) return ((uuid_is_nil(a, NULL)) ? 0 : 1); - /* We have to compare the hard way. */ - res = (int)((int64_t)a->time_low - (int64_t)b->time_low); - if (res) - return ((res < 0) ? -1 : 1); + /* + * We have to compare the hard way. + * + * Note that time_low is defined as unsigned 32-bit + * integer, therefore, with a significantly large + * a->time_low and a small b->time_low, we will end + * up with a value which is larger than 0x7fffffff + * which is negative if casted to signed 32-bit + * integer. + */ + res64 = (int64_t)a->time_low - (int64_t)b->time_low; + if (res64) + return ((res64 < 0) ? -1 : 1); res = (int)a->time_mid - (int)b->time_mid; if (res) return ((res < 0) ? -1 : 1); |
