Peter S. Mazinger - Re: apps built w (original) (raw)

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Re: apps built w/ -fstack-protector-all segfault

• From: "Peter S. Mazinger"
• To: Eric Christopher
• Cc: GCC Development
• Date: Tue, 15 Nov 2005 08:40:08 +0100 (CET)
• Subject: Re: apps built w/ -fstack-protector-all segfault

On Mon, 14 Nov 2005, Eric Christopher wrote:

this should also influence the -fstack-protector behaviour, but
that seems to be OK. __builtin_trap is used as I can see only if a vulnerability is
found, this happens though on a simple hello world.

Aaah. You'll probably need to step through the program in a debugger
then and find out where and why it segfaults.

app: #include <stdio.h>

int main() { printf("Hello\n"); return 0; }

I don't really know gdb how to use, but gdb run: Program received signal SIGSEGV, Segmentation fault. main () at tes.c:3 3 int main () {

bt #0 main () at tes.c:3

allowing it to core dump and running gdb against the core #... 0x0000000 in ?? () finally Error accessing memory address 0xc0000000: No such file or directory

The same built only w/ -fstack-protector is OK.

What else can I do to help finding the problem?

Apropos: there is another bug probably related to libssp.so use (does not influence the case here, due to __stack_chk_guard being in libc), it should write %{fstack-protector|fstack-protector-all: -lssp ....}, else for -fstack-protector-all it won't link against libssp.so

Thanks, Peter

-- Peter S. Mazinger ID: 0xA5F059F2 Key fingerprint = 92A4 31E1 56BC 3D5A 2D08 BB6E C389 975E A5F0 59F2

• References:
  • Re: apps built w/ -fstack-protector-all segfault
    * From: Eric Christopher