Re: [PATCH] Correctly handle symbols in VDSO
From: Jiri Olsa
Date: Wed Apr 09 2014 - 11:36:20 EST
On Wed, Apr 09, 2014 at 10:46:13AM +0400, Vladimir Nikulichev wrote:
> Hi,
>
> On Apr 8, 2014, at 7:41 PM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> > hi,
> > could you please put explanation from first email
> > into the patch changelog?
> >
> > cc-ing lkml
> >
> > thanks,
> > jirka
>
>
> OK, pasting it together:
ook
hum, your email's encoding kills my 'git am' :-\
also 'perf tools: Adjust symbols in VDSO' should go into the
email subject
I processed this patch by hand this time
thanks,
jirka
>
> ---------------------------------------------------------------------------------------------------------------------------
>
> perf tools: Adjust symbols in VDSO
>
> pert-report doesn't resolve function names in VDSO:
>
> $ perf report --stdio -g flat,0.0,15,callee --sort pid
> ...
> 8.76%
> 0x7fff6b1fe861
> __gettimeofday
> ACE_OS::gettimeofday()
> ...
>
> In this case symbol values should be adjusted the same way as for executables, relocatable objects and prelinked libraries.
>
> After fix:
>
> $ perf report --stdio -g flat,0.0,15,callee --sort pid
> ...
> 8.76%
> __vdso_gettimeofday
> __gettimeofday
> ACE_OS::gettimeofday()
> â
>
> Signed-off-by: Vladimir Nikulichev <nvs@xxxxxxxxxxx>
>
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 3b7dbf5..6864661 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -6,6 +6,7 @@
> #include <inttypes.h>
>
> #include "symbol.h"
> +#include "vdso.h"
> #include <symbol/kallsyms.h>
> #include "debug.h"
>
> @@ -618,6 +619,7 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
> GElf_Shdr shdr;
> ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
> ehdr.e_type == ET_REL ||
> + is_vdso_map(dso->short_name) ||
> elf_section_by_name(elf, &ehdr, &shdr,
> ".gnu.prelink_undo",
> NULL) != NULL);
--
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