From: Milian Wolff <mail@milianw.de>
To: elfutils-devel@sourceware.org
Subject: Re: How to debug broken unwinding?
Date: Wed, 07 Jun 2017 12:16:00 -0000 [thread overview]
Message-ID: <4288473.shuf9ekOC1@agathebauer> (raw)
In-Reply-To: <2244170.M6KXmO4ZXp@agathebauer>
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On Donnerstag, 1. Juni 2017 22:57:12 CEST Milian Wolff wrote:
> Hey all,
<snip>
> heaptrack_gui 2228 135073.400474: 613969 cycles:
> 108c8e [unknown] (/usr/lib/libQt5Core.so.5.8.0)
> @@ -533,8 +529,6 @@
> 2170af [unknown] (/usr/lib/libQt5Core.so.5.8.0)
> 297c53 QCoreApplicationPrivate::init (/usr/lib/
> libQt5Core.so.5.8.0)
> f7cde QGuiApplicationPrivate::init
> (/usr/lib/libQt5Gui.so. 5.8.0)
> - 1589e8 QApplicationPrivate::init
> (/usr/lib/libQt5Widgets.so. 5.8.0)
> - 78622 main (/home/milian/projects/compiled/other/bin/
> heaptrack_gui)
> 20439 __libc_start_main (/usr/lib/libc-2.25.so)
> 78299 _start (/home/milian/projects/compiled/other/bin/
> heaptrack_gui)
>
> NOTE: this is super odd, it simply misses two frames in the middle?!
This is really quite odd - looking at the debug output, the frames in the
middle are really just skipped for some reason:
unwind: access_mem addr 0x7ffca0a88330, val 4edc50, offset 2808
unwind: access_mem addr 0x7ffca0a88338, val 7f69bfce443a, offset 2816
unwind: pc: = 0x7f69c10fecde
found map: 7f69c1007000 7f69c1766000
dso found: libQt5Gui.so.5.8.0 /usr/lib/libQt5Gui.so.5.8.0
reported: libQt5Gui.so.5.8.0 /usr/lib/libQt5Gui.so.5.8.0, 1
unwind: QGuiApplicationPrivate::init():ip = 0x7f69c10fecde (0xf7cde)
-> so far so good, this frame is properly found inside libQt5Gui, but then:
unwind: pc: = 0x7f69bfce4439
found map: 7f69bfcc4000 7f69c0069000
dso found: libc-2.25.so /usr/lib/libc-2.25.so
reported: libc-2.25.so /usr/lib/libc-2.25.so, 1
unwind: __libc_start_main:ip = 0x7f69bfce4439 (0x20439)
-> the next frame is is supposedly the one in libc, but what happened to the
two frames in QApplicationPrivate::init and main? I also note that no calls to
access_mem are occuring - is this maybe some (wrong) caching in libdw or so
that interfers here?
Any insight would be appreciated, thanks!
--
Milian Wolff
mail@milianw.de
http://milianw.de
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next prev parent reply other threads:[~2017-06-02 13:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-02 11:53 Milian Wolff
2017-06-02 15:03 ` Milian Wolff
2017-06-07 12:16 ` Milian Wolff [this message]
2017-06-07 18:41 ` Milian Wolff
2017-06-14 18:27 ` Mark Wielaard
2017-06-15 17:45 ` Mark Wielaard
2017-06-13 16:17 ` Mark Wielaard
2017-06-14 13:12 ` Milian Wolff
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