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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug sanitizer/65479] sanitizer stack trace missing frames past #0 on powerpc64
Date: Fri, 10 Apr 2015 15:39:00 -0000 [thread overview]
Message-ID: <bug-65479-4-Nj80Sfr9zU@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-65479-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65479
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Martin Sebor from comment #5)
> Created attachment 35289 [details]
> Test case demonstrating stability problem with backtrace_qsort.
>
> Attached is a demo program showing the stability bug in the backtrace_qsort
> function. The output shows the result of the current implementation
> (Unstable) and the expected result (Stable). A better test case wouldn't
> rely on the knowledge of the line_compare function and instead arrange to
> construct a DWARF line program with similar properties that would then cause
> the backtrace line problem. I suspect that would take quite a bit of effort
> to put together, especially if we wanted it to be reproducible across
> targets.
>
> I plan to work on the fast unwinding but I don't expect it to be ready in
> time for the 5.0 release. In the meantime, I'll post a patch to fix the
> test failures and maintain stability to be considered for 5.0.
That hints at a bug in the line_compare function, what it does is just bogus.
Adding the idx field to struct line sounds IMHO like the right thing, and on
64-bit arches won't even eat any extra memory because there have been 32 bits
of padding.
next prev parent reply other threads:[~2015-04-10 15:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-19 23:02 [Bug sanitizer/65479] New: " msebor at gcc dot gnu.org
2015-03-20 2:49 ` [Bug sanitizer/65479] " msebor at gcc dot gnu.org
2015-04-01 1:14 ` msebor at gcc dot gnu.org
2015-04-10 2:14 ` msebor at gcc dot gnu.org
2015-04-10 6:27 ` jakub at gcc dot gnu.org
2015-04-10 15:31 ` msebor at gcc dot gnu.org
2015-04-10 15:39 ` jakub at gcc dot gnu.org [this message]
2015-04-12 23:46 ` msebor at gcc dot gnu.org
2015-04-13 18:32 ` msebor at gcc dot gnu.org
2015-04-20 1:38 ` msebor at gcc dot gnu.org
2015-06-12 0:02 ` msebor at gcc dot gnu.org
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