Ubuntu
gdb package

SIGTRAP and crash when single-stepping through multithreaded program

Bug #26041 reported by Gary Coady
10
This bug affects 1 person
Affects Status Importance Assigned to Milestone
gdb (Ubuntu)
Fix Released
Medium
Unassigned

Bug Description

When single-stepping through a program: if a new thread is created, a SIGTRAP is
received, followed by a SEGFAULT.

(gdb) step
[New Thread -1211221072 (LWP 4401)]

Program received signal SIGTRAP, Trace/breakpoint trap.
[Switching to Thread -1210680400 (LWP 4365)]
0xb7f57861 in __nptl_create_event () from /lib/tls/i686/cmov/libpthread.so.0
(gdb) next
Single stepping until exit from function __nptl_create_event,
which has no line number information.
0x007d0f00 in ?? ()
(gdb) cont
Continuing.

Program received signal SIGSEGV, Segmentation fault.
0x007d0f00 in ?? ()
(gdb)

The checkins at
http://sources.redhat.com/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=2015
seem to fix the problem. Could this be considered for inclusion in dapper?

Thanks,
Gary.

Revision history for this message
Gary Coady (garycoady) wrote :

Current gdb version is 6.3-6ubuntu2.

Revision history for this message
Gary Coady (garycoady) wrote :

Dapper now has gdb 6.4, so this crash no longer occurs.
If a new thread spawns while single-stepping, the thread may stop single-stepping (headache-inducing), but that's a different bug.

Can this bug be closed?

Revision history for this message
Matt Zimmerman (mdz) wrote :

According to comments, this bug is fixed in Dapper

Changed in gdb:
status: Unconfirmed → Fix Released
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