Red Hat Bugzilla – Bug 117972
signal backtrace broken
Last modified: 2007-11-30 17:07:00 EST
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Description of problem:
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.set a breakpoint in a signal handler
2.run to the signal handler
3.do a backtrace
Actual Results: (gdb) break handler
Breakpoint 1 at 0x10000470: file /tmp/segv.c, line 9.
Starting program: /tmp/segv.32
Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) signal SIGSEGV
Continuing with signal SIGSEGV.
Breakpoint 1, handler (sig=11, info=0xffffe390, context=0x100004f4)
warning: Source file is more recent than executable.
9 exit (0);
#0 handler (sig=11, info=0xffffe390, context=0x100004f4) at /tmp/segv.c:9
#1 <signal handler called>
Cannot access memory at address 0xffffe430
handler (int sig, siginfo_t *info, ucontext_t *context)
handler (int sig, int code, struct sigcontext *scp)
segv (void (*f) (void))
static struct sigaction action;
action.sa_sigaction = handler;
action.sa_flags |= SA_SIGINFO;
action.sa_handler = handler;
sigaction (SIGSEGV, &action, NULL);
*** Bug 85247 has been marked as a duplicate of this bug. ***
*** Bug 85309 has been marked as a duplicate of this bug. ***
Changing product and version.
- None of them handle this alternative signal handler, overhauling
signal handler unwinders to fix.
*** Bug 117028 has been marked as a duplicate of this bug. ***
I see this is "Platform: All", but I thought this was fixed on IA64
with the libunwind based gdb?
Yes, libunwind fixes the ia64 specific backtrace. Unfortunatly it
doesn't fix step/finish/return/next when presented with such a stack
:-( Both architecture specific and generic fixes are needed.
*** Bug 121656 has been marked as a duplicate of this bug. ***
hijack summary to mirror for 121656
Can somebody explain to me why most bugs related to this one are
secret? I fail to see how being unable to walk the stack in gdb can
relate to anything security sensitive, especially bug 121656 that has
been closed as a duplicate of this one.
It's quite annoying that almost every time I get an e-mail about this
bug it says the equivalent of "Something changed but I won't tell you
what, nyah, nyah.".
----- Additional Comments From firstname.lastname@example.org(prefers email via email@example.com) 2004-09-02 15:50 -------
*** Bug 8850 has been marked as a duplicate of this bug. ***
This bug is NEEDINFO, but I cannot find any request for more info. Is
any information needed, and if so, what, or has the Status just not
What |Removed |Added
Target Milestone|RHEL3_U4 |RHEL3_U6
------- Additional Comments From firstname.lastname@example.org(prefers email via email@example.com) 2005-07-11 15:22 EDT -------
RHEL3-U4 is already out, so moving the target-milestone to RHEL3-U6.