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SubjectRe: [PATCH 3/3] perf report: don't crash on invalid inline debug information
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On Donnerstag, 11. Oktober 2018 21:39:20 CEST Arnaldo Carvalho de Melo wrote:
> Em Thu, Oct 11, 2018 at 08:23:31PM +0200, Milian Wolff escreveu:
> > On Donnerstag, 27. September 2018 21:10:37 CEST Arnaldo Carvalho de Melo
> >
> > wrote:
> > > Em Wed, Sep 26, 2018 at 03:52:07PM +0200, Milian Wolff escreveu:
> > > > When the function name for an inline frame is invalid, we must
> > > > not try to demangle this symbol, otherwise we crash with:
> > > >
> > > > #0 0x0000555555895c01 in bfd_demangle ()
> > > > #1 0x0000555555823262 in demangle_sym (dso=0x555555d92b90,
> > > > elf_name=0x0,
> > > > kmodule=0) at util/symbol-elf.c:215 #2 dso__demangle_sym
> > > > (dso=dso@entry=0x555555d92b90, kmodule=<optimized out>,
> > > > kmodule@entry=0,
> > > > elf_name=elf_name@entry=0x0) at util/symbol-elf.c:400 #3
> > > > 0x00005555557fef4b in new_inline_sym (funcname=0x0,
> > > > base_sym=0x555555d92b90, dso=0x555555d92b90) at util/srcline.c:89 #4
> > > > inline_list__append_dso_a2l (dso=dso@entry=0x555555c7bb00,
> > > > node=node@entry=0x555555e31810, sym=sym@entry=0x555555d92b90) at
> > > > util/srcline.c:264 #5 0x00005555557ff27f in addr2line
> > > > (dso_name=dso_name@entry=0x555555d92430
> > > > "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fc
> > > > e5/
> > > > elf", addr=addr@entry=2888, file=file@entry=0x0,>
> > > >
> > > > line=line@entry=0x0, dso=dso@entry=0x555555c7bb00,
> > > > unwind_inlines=unwind_inlines@entry=true, node=0x555555e31810,
> > > > sym=0x555555d92b90) at util/srcline.c:313>
> > > >
> > > > #6 0x00005555557ffe7c in addr2inlines (sym=0x555555d92b90,
> > > > dso=0x555555c7bb00, addr=2888, dso_name=0x555555d92430
> > > > "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fc
> > > > e5/
> > > > elf")>
> > > >
> > > > at util/srcline.c:358
> > > >
> > > > So instead handle the case where we get invalid function names
> > > > for inlined frames and use a fallback '??' function name instead.
> > > >
> > > > While this crash was originally reported by Hadrien for rust code,
> > > > I can now also reproduce it with trivial C++ code. Indeed, it seems
> > > > like libbfd fails to interpret the debug information for the inline
> > > > frame symbol name:
> > > >
> > > > $ addr2line -e
> > > > /home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce
> > > > 5/e
> > > > lf -if b48 main
> > > > /usr/include/c++/8.2.1/complex:610
> > > > ??
> > > > /usr/include/c++/8.2.1/complex:618
> > > > ??
> > > > /usr/include/c++/8.2.1/complex:675
> > > > ??
> > > > /usr/include/c++/8.2.1/complex:685
> > > > main
> > > > /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining
> > > > /mai
> > > > n.cpp:39
> > > >
> > > > I've reported this bug upstream and also attached a patch there
> > > > which should fix this issue:
> > > > https://sourceware.org/bugzilla/show_bug.cgi?id=23715
> > >
> > > Millian, what about this one, which is the cset it is fixing?
> >
> > Hey Arnaldo,
> >
> > just noticed this email and that the corresponding patch hasn't landed in
> > perf/core yet. The patch set which introduced this is a64489c56c307 ("perf
> > report: Find the inline stack for a given address"). Note that the code
> > was
> > introduced by this patch, but then subsequently touched and moved by
> > follow up patches. So, is this the patch you want to see referenced?
> > Otherwise, the latest patch which gets fixed is afaik: 7285cf3325b4a
> > ("perf srcline: Show correct function name for srcline of callchains").
> >
> > Can you please pick either of these patches and amend the commit message
> > of my patch and push it to perf/urgent and perf/core?
>
> I'll reread all this later or tomorrow and continue, going AFK now.

Ping?

--
Milian Wolff | milian.wolff@kdab.com | Senior Software Engineer
KDAB (Deutschland) GmbH, a KDAB Group company
Tel: +49-30-521325470
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