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[Bug libgcc/81383] -fstack-protector doesn't work well
- From: "hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 10 Jul 2017 16:34:46 +0000
- Subject: [Bug libgcc/81383] -fstack-protector doesn't work well
- Auto-submitted: auto-generated
- References: <bug-81383-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81383
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |REOPENED
Resolution|WONTFIX |---
--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> ---
[hjl@gnu-6 tmp]$ cat ssp-1.c
#ifndef LOOP
#define LOOP 400
#endif
int main (void)
{
int i = 0;
char foo[255];
/* Overflow buffer. */
for (i = 0; i < LOOP; i++)
foo[i] = 42;
return 1; /* fail */
}
[hjl@gnu-6 tmp]$ gcc ssp-1.c -g -fstack-protector
[hjl@gnu-6 tmp]$ gdb a.out
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Reading symbols from a.out...done.
(gdb) r
Starting program: /tmp/a.out
Missing separate debuginfos, use: dnf debuginfo-install
glibc-2.24-9.0.fc25.x86_64
*** stack smashing detected ***: /tmp/a.out terminated
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7806c8b in ?? () from /lib64/libgcc_s.so.1
Missing separate debuginfos, use: dnf debuginfo-install
libgcc-6.3.1-3.2.fc25.x86_64
(gdb) bt
#0 0x00007ffff7806c8b in ?? () from /lib64/libgcc_s.so.1
#1 0x00007ffff7808628 in _Unwind_Backtrace () from /lib64/libgcc_s.so.1
#2 0x00007ffff7b26b8f in backtrace () from /lib64/libc.so.6
#3 0x00007ffff7a2efb6 in backtrace_and_maps () from /lib64/libc.so.6
#4 0x00007ffff7a886eb in __libc_message () from /lib64/libc.so.6
#5 0x00007ffff7b2a387 in __fortify_fail () from /lib64/libc.so.6
#6 0x00007ffff7b2a350 in __stack_chk_fail () from /lib64/libc.so.6
#7 0x0000000000400592 in main () at ssp-1.c:15
(gdb)
_Unwind_Backtrace shouldn't crash