Bug 1018549 - needless libunwind dependency
Summary: needless libunwind dependency
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: xorg-x11-server
Version: rawhide
Hardware: Unspecified
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: X/OpenGL Maintenance List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks: 1018550
TreeView+ depends on / blocked
 
Reported: 2013-10-13 07:35 UTC by Jan Kratochvil
Modified: 2014-03-21 01:58 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
: 1018550 (view as bug list)
Environment:
Last Closed: 2014-03-21 01:58:18 UTC
Type: Bug


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
FreeDesktop.org 70746 0 None None None Never

Description Jan Kratochvil 2013-10-13 07:35:41 UTC
I have found Fedora xorg-x11-server depends on libunwind.  There is a longterm plan to obsolete libunwind from Fedora by new elfutils unwinder.  But xorg-x11-server does not even need any external (non-glibc) unwinder.

According to
        http://pkgs.fedoraproject.org/cgit/xorg-x11-server.git/tree/0001-os-use-libunwind-to-generate-backtraces.patch

you do only self-backtrace (called local unwinding by libunwind).  glibc
backtrace() can do the same.  According to the sample backtrace in the patch
above the backtrace addresses there are the same in before/after cases,
libunwind only adds resolving of address -> symbol name there, IIUC.

address -> symbol name resolving can be done with RH-supported elfutils
package, a simple self-backtrace with symbol resolving is for example:
       	http://people.redhat.com/jkratoch/backtracei.c

Comment 1 Peter Hutterer 2013-10-22 05:11:07 UTC
moved upstream https://bugs.freedesktop.org/show_bug.cgi?id=70746

Comment 2 Peter Hutterer 2014-03-21 01:58:18 UTC
Discussion from upstream ended with:
"That is without fork()+exec() libunwind is currently the best there is for
xserver."
http://lists.x.org/archives/xorg-devel/2013-October/038475.html

Closing this for now


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