From: Arnaldo Carvalho de Melo <acme@redhat.com>
To: Stephane Eranian <eranian@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Jiri Olsa <jolsa@redhat.com>,
Namhyung Kim <namhyung@kernel.org>,
David Ahern <dsahern@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
"mingo@elte.hu" <mingo@elte.hu>
Subject: Re: [BUG] perf report: fails to symbolize when vaddr is non zero for shared objects
Date: Tue, 16 Jun 2015 11:34:01 -0300 [thread overview]
Message-ID: <20150616143401.GA2548@redhat.com> (raw)
In-Reply-To: <CABPqkBTPruhg+B3N899vEJtAsd8ihDs+oMjOB_C8Xs=ZZE-FDQ@mail.gmail.com>
Em Tue, Jun 16, 2015 at 12:03:01AM -0700, Stephane Eranian escreveu:
> Hi,
>
> It has been brought to my attention that on systems where the text
> of shared libs is not loaded with a zero virtual address, perf report
> fails to symbolize
> correctly samples. This is true of older versions of perf and also the latest
> in tip.git.
>
> I looked at symbol-elf.c and I did not see a place where the vaddr was taken
> into account from the program headers in the case of ET_DYN. I see it for
> ET_EXE, though.
>
> $ readelf -e lib.so
> Type: DYN (Shared object file)
> ....
> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
> LOAD 0x000000 0x0000d000 0x0000d000 0x73657c 0x73657c R E 0x1000
>
> If you get samples in the shared lib, they will be off, possibly
> attributed to the wrong
> functions.
>
> Could this be fixed quickly?
You tell me, do you have a patch to propose? :-)
- Arnaldo
next prev parent reply other threads:[~2015-06-16 14:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-16 7:03 [BUG] perf report: fails to symbolize when vaddr is non zero for shared objects Stephane Eranian
2015-06-16 14:34 ` Arnaldo Carvalho de Melo [this message]
2015-06-17 18:54 ` Stephane Eranian
2015-06-17 19:24 ` Arnaldo Carvalho de Melo
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