Re: Restarting gdbserver

Jan Kratochvil
2011-01-23T18:20:03Z

On Sun, 23 Jan 2011 19:05:42 +0100, Leon Pollak wrote:
> OK, to check myself and understand your explanation, I compiled the same
> application in the "normal" Fedora 12 - it does show the backtrace.

OK, so you do not have debug info in either case.

But on x86* Fedora you can backtrace any system code even if you do not have
the debug info installed. (This is not true for any x86* code but Fedora is
using -fasynchronous-unwind-tables so it can backtrace even
-fomit-frame-pointer code without debug info.)

On arm I guess - I do not know arm - you need debug info for the backtrace.
But this is very montavista distro specific question and in fact offtopic here.

> From To Syms Read Shared Object Library
[...]
> 0x008145e0 0x00820518 Yes (*) /lib/libpthread.so.0
[...]
> (*): Shared library is missing debugging information.
> (gdb) bt
> #0 0x00110430 in __kernel_vsyscall ()
> #1 0x0081a22c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0

This record shows the debug info is missing. You can try
`debuginfo-install glibc' on Fedora to get the debug info. Still it does not
affect the capability of backtracing on x86*.

> And I searched my Fedora installatoin - no *debug*.so at all.

You would need to install it first:

# repoquery -q --enablerepo='fedora*-debuginfo' glibc-debuginfo
glibc-debuginfo-0:2.12.90-17.i686
# debuginfo-install glibc
# ls -lL /usr/lib/debug/lib/libpthread.so.0.debug
-r--r--r-- 1 root root 708656 Dec 14 17:53 /usr/lib/debug/lib/libpthread.so.0.debug
(Adjusted from x86_64 as you seem to run 32bit.)

Regards,
Jan