Description of problem: memchr(0, 'a', 0) can evoke a segfault

Version-Release number of selected component (if applicable): glibc-headers-2.9.90-22.x86_64


How reproducible: every time


Steps to Reproduce:

$ cat k.c
#include <string.h>
int main() { return !!(memchr (0, 'a', 0)); }
$ gcc -O k.c; ./a.out
 
Actual results:

Segmentation fault
[Exit 139 (SIGSEGV)]

Expected results:
no segfault

Additional info: