[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Libunwind-devel] unwinding from signal handler (i586)

From: Ken Werner
Subject: Re: [Libunwind-devel] unwinding from signal handler (i586)
Date: Tue, 30 Aug 2011 08:57:34 +0200
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv: Gecko/20110805 Lightning/1.0b2 Thunderbird/3.1.12

On 08/22/2011 12:12 PM, Sven Neumann wrote:
On Mon, 2011-08-22 at 13:03 +0300, Lassi Tuura wrote:

# ./main
standard frame  ip:  0x80488f3, sp: 0xbfbcea00   sig_handler
Segmentation fault

I will try to find some time to debug this further...

In the hope that it helps, here's the libunwind debug output from this
segmentation fault:

# UNW_DEBUG_LEVEL=9999 ./main

access_reg: ebp ->  bfb4ebe8
access_mem: mem[bfb4ebec] ->  0
_Ux86_dwarf_step: returning 0
_Ux86_step: returning 0
Segmentation fault

Does it actually crash in libunwind? From above it sounds like it already
returned fine to your application and crashes there.

Well, the code I am running is the test-case that Ken posted earlier in
this thread.

I was not able to reproduce the segfault on my i686 system (Ubuntu 11.04). This is how I've built libunwind on this machine:
  autoreconf -i
  ./configure CFLAGS="-U_FORTIFY_SOURCE"
  make -j`getconf _NPROCESSORS_ONLN`

The testcase passes with and without USE_TIMER defined:
  LD_LIBRARY_PATH=../../src/.libs ./main
  standard frame        ip:  0x8048873, sp: 0xbfa2b670   sig_handler
  signal frame  ip: 0x4009ff10, sp: 0xbfa2bc10   killpg
  standard frame        ip:  0x8048b90, sp: 0xbfa2bd20   main
  standard frame        ip: 0x4008be37, sp: 0xbfa2bd30   __libc_start_main
  standard frame        ip:  0x80487a1, sp: 0xbfa2bdb0   _start

When running the testsuite I see two failing testcases which are both unrelated to local unwinding:
  FAIL: test-setjmp
  FAIL: test-ptrace


reply via email to

[Prev in Thread] Current Thread [Next in Thread]