| Summary: | FEAT: libunwind-using-elfutils for symbols resolving | ||
|---|---|---|---|
| Product: | frysk | Reporter: | Mike Cvet <mcvet> |
| Component: | general | Assignee: | Jan Kratochvil <jan> |
| Status: | ASSIGNED --- | ||
| Severity: | normal | CC: | cagney, mcvet, pmuldoon |
| Priority: | P2 | ||
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | ||
| Bug Depends on: | |||
| Bug Blocks: | 3076, 3917, 4059 | ||
| Attachments: |
Test program.
gcc -g -S stepper.c Implementation (v2). Implementation (v4). |
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Description
Mike Cvet
2007-02-20 22:32:57 UTC
Created attachment 1570 [details]
Test program.
When instruction stepping into jump(), foo() will dissapear on jump()'s first
instruction and then re-appear after more stepping.
Created attachment 1571 [details]
gcc -g -S stepper.c
Problem is that -fasynchronous-unwind-tables is not default on i?86 and so .eh_frame is not present there. .eh_frame is the only unwind information currently supported by libunwind. GDB supports also .debug_frame (generated by -g) and so it handles the case without problem. libunwind supports heuristics for unwinding without .eh_frame in general cases (function bodies) but it fails in the prologue as was reported here. libunwind support for .debug_frame has been discussed at: http://lists.gnu.org/archive/html/libunwind-devel/2007-02/msg00000.html Considering this Bug as a tracker for libunwind based on elfutils unwinding method. Created attachment 1597 [details]
Implementation (v2).
Currently it passes the testsuite (tested on x86) with some exceptions below.
Performance looks as a bit lower but it was not investigated so far.
Code could be cleaned up a bit but some David Mosberger-Tang internal API
advices could be helpful.
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=230903 Bug 230903: FEAT: dwfl_module_addrname() should also return lowpc+highpc results in this current libunwind-using-elfutils testsuite regression: Backtrace does not match on level==7, want "_start+", got "_start" FAILURE: detected 1 errors FAIL: run-ptrace-stepper Backtrace does not match on level==5, want "_start+", got "_start" FAILURE: detected 1 errors Backtrace does not match on level==5, want "_start+", got "_start" FAILURE: detected 1 errors Backtrace does not match on level==5, want "_start+", got "_start" FAILURE: detected 1 errors Backtrace does not match on level==5, want "_start+", got "_start" FAILURE: detected 1 errors XFAIL: run-ptrace-signull Implementation currently needs for VDSO symbols resolving a kernel workaround https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=230850 Bug 230850: [kernel] /proc/PID/mem is not readable implemented to elfutils; needed on kernel-xen-2.6.19-1.2898.2.3.fc7.i686. Some unlisted libunwind-using-elfutils testsuite regressions apply otherwise. Implementation currently recommends to rather use an elfutils bugfix https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=230793 Bug 230793: File descriptors leakage Some unlisted libunwind-using-elfutils testsuite regressions apply otherwise (the regressions may no longer be true as elfutils caching is now implemented). Created attachment 1599 [details] Implementation (v4). Tested/bugfixed now also on x86_64. It should be usable with elfutils-0.126-1 (only https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=230793 fix is recommended). |