summary: Test for bz689471 (SSE4 strncmp failure)
description: |
    Bug summary: SSE4 strncmp failure
    Bugzilla link: https://bugzilla.redhat.com/show_bug.cgi?id=689471

    Description:

    H.J. Lu      2011-03-21 05:42:34 CET  
    On Intel Core i7, I got

    [hjl@gnu-6 997]$ cat saved.c
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/mman.h>

    int main()
    {
        char *buf, *buf2;

        buf = (char*)mmap((void*)0x100000000, 0x2000 * 2,
                          PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
        buf = mmap((char *)buf, 0x2000, PROT_READ | PROT_WRITE,
                   MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
        memset(buf, 'a', 0x2000);
        buf[0x1fff] = 0;
        buf2 = strdup(buf);
        if (strncmp (buf + 3994, buf2 + 2635, 6241) >= 0)
          abort ();

        return 0;
    }
    [hjl@gnu-6 997]$ gcc saved.c
    [hjl@gnu-6 997]$ ./a.out 
    Segmentation fault
    [hjl@gnu-6 997]$ gdb a.out 
    GNU gdb (GDB) 7.2.50.20110312-cvs
    Copyright (C) 2011 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
    and "show warranty" for details.
    This GDB was configured as "x86_64-unknown-linux-gnu".
    For bug reporting instructions, please see:
    <http://www.gnu.org/software/gdb/bugs/>...
    Reading symbols from /export/home/hjl/bugs/libc/997/a.out...(no debugging
    symbols found)...done.
    (gdb) r
    Starting program: /export/home/hjl/bugs/libc/997/a.out 

    Program received signal SIGSEGV, Segmentation fault.
    0x0000003f7d3214a0 in __strncmp_sse42 () from /lib64/libc.so.6
    (gdb)
contact: Miroslav Franc <mfranc@redhat.com>
component:
  - glibc
test: ./runtest.sh
framework: beakerlib
recommend:
  - glibc
  - gcc
duration: 15m
link:
  - relates: https://bugzilla.redhat.com/show_bug.cgi?id=689471
extra-summary: /tools/glibc/Regression/bz689471-SSE4-strncmp-failure
extra-task: /tools/glibc/Regression/bz689471-SSE4-strncmp-failure