Commit 4331236e authored Oct 05, 2021 by Roberto Sassu Committed by Greg Kroah-Hartman Oct 20, 2021

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: 1da177e4 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b25e0bf3

arch/s390/lib/string.c

+7 −8

Original line number	Diff line number	Diff line
		@@ -227,13 +227,12 @@ EXPORT_SYMBOL(strcmp);
		*/
		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);
		} while (--len >= 0);
		return NULL;
		}
		EXPORT_SYMBOL(strrchr);