Bug 497866

Summary: gdb cannot resolve symbols after prelink
Product: [Fedora] Fedora Reporter: Oliver Henshaw <oliver.henshaw>
Component: gdbAssignee: Jan Kratochvil <jan.kratochvil>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: low    
Version: 10CC: dvlasenk, jan.kratochvil
Target Milestone: ---Keywords: Triaged
Target Release: ---   
Hardware: i686   
OS: Linux   
Whiteboard:
Fixed In Version: 7.0-13.fc12.x86_64 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-12-18 09:22:05 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
gdb kded4 before additional debuginfo-install and prelink
none
gdb kded4 after additional debuginfo-install and prelink none

Description Oliver Henshaw 2009-04-27 16:12:58 UTC
Description of problem:

I'm using gdb & pstack to take backtraces of a problematic kded4 while it's running (it's spending 40% of the cpu in the kernel). I had already debuginfo-installed the package kded4 belongs to and the packages needed to fill in the question marks seen after the first run of pstack. I then ran a backtrace inside gdb (because of already reported problems with pstack) and installed all the debuginfo packages it recommended.

After this, but before the next time I tried to get a backtrace, prelink ran. Now a gdb backtrace gives me much less information than before (see attached files). I'm not sure how well gdb should cope with resolving symbols from re-prelinked libraries, when the executable it's attached to linked against the old libraries, but I see that it's trying at least.

I see lots of lines like "/usr/sbin/prelink: /usr/lib/debug/usr/bin/kded4.debug: PT_INTERP segment not corresponding to .interp section" in the prelink log. Don't know whether that's relevant.

Version-Release number of selected component (if applicable):
prelink-0.4.0-3.i386
gdb-6.8-29.fc10.i386
yum-utils-1.1.19-1.fc10.noarch

Comment 1 Oliver Henshaw 2009-04-27 16:14:43 UTC
Created attachment 341454 [details]
gdb kded4 before additional debuginfo-install and prelink

Comment 2 Oliver Henshaw 2009-04-27 16:15:34 UTC
Created attachment 341455 [details]
gdb kded4 after additional debuginfo-install and prelink

Comment 3 Jan Kratochvil 2009-04-27 18:12:51 UTC
(In reply to comment #0)
> I see lots of lines like "/usr/sbin/prelink:
> /usr/lib/debug/usr/bin/kded4.debug: PT_INTERP segment not corresponding to
> .interp section" in the prelink log. Don't know whether that's relevant.

This part is a known prelink bug although it is completely harmless.

Otherwise thanks for a valid bugreport, one can suggest restarting the inferior as a workaround.

Comment 4 Bug Zapper 2009-11-18 11:52:04 UTC
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Comment 5 Bug Zapper 2009-12-18 09:22:05 UTC
Fedora 10 changed to end-of-life (EOL) status on 2009-12-17. Fedora 10 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.

Comment 6 Jan Kratochvil 2010-01-03 17:14:55 UTC
I find it as working with: gdb-7.0-13.fc12.x86_64

rm -f /tmp/pause;echo -e '#include <unistd.h>\nint main (void) { return pause (); }' >/tmp/pause.c;gcc -fPIE -pie -o /tmp/pause -Wall -g /tmp/pause.c;/tmp/pause&p=$!;sleep 1;prelink -RN /tmp/pause;gdb -nx -ex 'set confirm no' -ex bt -ex q /tmp/pause $p

#0  0x00007fb3f465bd00 in __pause_nocancel () at ../sysdeps/unix/syscall-template.S:82
#1  0x00007fb3f4b50705 in main () at /tmp/pause.c:2

Comment 7 Oliver Henshaw 2010-01-29 19:08:40 UTC
I can confirm this with the test in comment #6 as well as with the original kded case.