klibc-bot for Ben Hutchings
2022-Dec-30 22:03 UTC
[klibc] [klibc:master] strstr, memmem: Handle zero-length needle correctly
Commit-ID: bf50476c204f7eab1fba5370a49fb03fcfaf92d1
Gitweb:
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=bf50476c204f7eab1fba5370a49fb03fcfaf92d1
Author: Ben Hutchings <ben at decadent.org.uk>
AuthorDate: Fri, 30 Dec 2022 22:48:59 +0100
Committer: Ben Hutchings <ben at decadent.org.uk>
CommitDate: Fri, 30 Dec 2022 23:01:22 +0100
[klibc] strstr, memmem: Handle zero-length needle correctly
strstr(haystack, "") and memmem(haystack, n, needle, 0) should
return haystack, not NULL.
- Handle the !m and (m > n || !n) cases separately at the top.
- Delete the !n condition. After handling !m we know m > 0,
so checking for !n is redundant with m > n.
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
usr/klibc/memmem.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/usr/klibc/memmem.c b/usr/klibc/memmem.c
index 8b5faa00..72422aa4 100644
--- a/usr/klibc/memmem.c
+++ b/usr/klibc/memmem.c
@@ -18,7 +18,10 @@ void *memmem(const void *haystack, size_t n, const void
*needle, size_t m)
size_t j, k, l;
- if (m > n || !m || !n)
+ if (!m)
+ return (void *)haystack;
+
+ if (m > n)
return NULL;
if (1 != m) {