Red Hat Bugzilla – Bug 6281
Attaching to external process segfaults. Process being attached to locks up.
Last modified: 2008-05-01 11:37:52 EDT
When gdb is attached to an existing process, the 'info files' command causes gdb to segfault. The process being traced locks up, and must be kill -9ed. This severely impacts the Data Display Debugger front end for gdb. I cannot find a workaround. Script started on Fri Oct 22 22:45:31 1999 [mrsam@gwl testdir]$ rpm -q egcs egcs-1.1.2-24 [mrsam@gwl testdir]$ rpm -q gdb gdb-4.18-4 [mrsam@gwl testdir]$ cat t.c int main() { sleep(500); return (0); } [mrsam@gwl testdir]$ gcc -g -o t t.c [mrsam@gwl testdir]$ ./t & [1] 9788 [mrsam@gwl testdir]$ gdb t 9788 GNU gdb 4.18 Copyright 1998 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-redhat-linux"... /usr/home/mrsam/testdir/9788: No such file or directory. Attaching to program: /usr/home/mrsam/testdir/t, Pid 9788 Reading symbols from /lib/libc.so.6...done. Reading symbols from /lib/ld-linux.so.2...done. 0x400a87f1 in __libc_nanosleep () from /lib/libc.so.6 (gdb) info files Symbols from "/usr/home/mrsam/testdir/t". Unix child process: Using the running image of attached Pid 9788. While running this, GDB does not access memory from... Local exec file: `/usr/home/mrsam/testdir/t', file type elf32-i386. Entry point: 0x8048320 Segmentation fault (core dumped) [mrsam@gwl testdir]$ exit Script done on Fri Oct 22 22:46:02 1999
I was able to reproduce this with the GDB which ships with Red Hat Linux 6.1. I then tried a development version of GDB (see http://sourceware.cygnus.com/gdb/) and did not see the problem. So it is presumably fixed in gdb-4.18-6 which is in rawhide (or failing that, a GDB you build yourself from the development sources).