s390: fix strrchr() implementation

Fix two problems found in the strrchr() implementation for s390
architectures: evaluate empty strings (return the string address instead of
NULL, if '\0' is passed as second argument); evaluate the first character
of non-empty strings (the current implementation stops at the second).

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reported-by: Heiko Carstens <hca@linux.ibm.com> (incorrect behavior with empty strings)
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Link: https://lore.kernel.org/r/20211005120836.60630-1-roberto.sassu@huawei.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Roberto Sassu 2021-10-05 14:08:36 +02:00 committed by Vasily Gorbik
parent 4540938952
commit 8e0ab8e26b
1 changed files with 6 additions and 7 deletions

View File

@ -259,14 +259,13 @@ EXPORT_SYMBOL(strcmp);
#ifdef __HAVE_ARCH_STRRCHR
char *strrchr(const char *s, int c)
{
size_t len = __strend(s) - s;
ssize_t len = __strend(s) - s;
if (len)
do {
if (s[len] == (char) c)
return (char *) s + len;
} while (--len > 0);
return NULL;
do {
if (s[len] == (char)c)
return (char *)s + len;
} while (--len >= 0);
return NULL;
}
EXPORT_SYMBOL(strrchr);
#endif