From c1b29cee414651e96a3651c4d9b23ebd9e358406 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Tue, 5 Oct 2021 14:08:36 +0200 Subject: s390: fix strrchr() implementation commit 8e0ab8e26b72a80e991c66a8abc16e6c856abe3d upstream. 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: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Heiko Carstens (incorrect behavior with empty strings) Signed-off-by: Roberto Sassu Link: https://lore.kernel.org/r/20211005120836.60630-1-roberto.sassu@huawei.com Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/lib/string.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c index b647d5ff0ad9..ac67fa0f2e4d 100644 --- a/arch/s390/lib/string.c +++ b/arch/s390/lib/string.c @@ -225,14 +225,13 @@ EXPORT_SYMBOL(strcmp); */ char * strrchr(const char * s, int c) { - size_t len = __strend(s) - s; - - if (len) - do { - if (s[len] == (char) c) - return (char *) s + len; - } while (--len > 0); - return NULL; + ssize_t len = __strend(s) - s; + + do { + if (s[len] == (char)c) + return (char *)s + len; + } while (--len >= 0); + return NULL; } EXPORT_SYMBOL(strrchr); -- cgit v1.2.3