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Re: frame unwinding patches
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- To: Milian Wolff <mail at milianw dot de>
- Cc: elfutils-devel at sourceware dot org, Mark Wielaard <mark at klomp dot org>, Ulf Hermann <ulf dot hermann at qt dot io>
- Date: Mon, 3 Apr 2017 23:23:25 +0200
- Subject: Re: frame unwinding patches
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On Mon, 03 Apr 2017 11:00:03 +0200, Milian Wolff wrote:
> I just got a report from a colleague. As-is, elfutils would fail to unwind
> from the following location in his application:
>
> 0x1137ca4
>
> With the x86_64 patch applied, he got a proper backtrace:
S/he has something wrong with the compiler. With -fasynchronous-unwind-tables
frame pointer unwinding is never needed
and gcc defaults to -fasynchronous-unwind-tables on x86_64.
This is why I haven't implemented it originally as it only paper overs the
real problem and it leads to unreliable backtraces in longterm.
Jan