Messages in this thread Patch in this message | | | Date | Wed, 14 Jan 2015 11:22:10 +0000 | From | Will Deacon <> | Subject | Re: [PATCH 1/2] perf symbols: Ignore mapping symbols on aarch64 |
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On Tue, Jan 13, 2015 at 04:59:03PM +0000, Victor Kamensky wrote: > Aarch64 ELF files use mapping symbols with special names $x, $d > to identify regions of Aarch64 code (see Aarch64 ELF ABI - "ARM > IHI 0056B", section "4.5.4 Mapping symbols"). > > The patch filters out these symbols at load time, similar to > "696b97a perf symbols: Ignore mapping symbols on ARM" changes > done for ARM before V8. > > Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Arnaldo Carvalho de Melo <acme@kernel.org> > Cc: Adrian Hunter <adrian.hunter@intel.com> > Cc: Jiri Olsa <jolsa@redhat.com> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Avi Kivity <avi@cloudius-systems.com> > Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> > Cc: Anton Blanchard <anton@samba.org> > Cc: David Ahern <dsahern@gmail.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Dave Martin <Dave.Martin@arm.com> > --- > tools/perf/util/symbol-elf.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c > index 06fcd1b..1e188dd 100644 > --- a/tools/perf/util/symbol-elf.c > +++ b/tools/perf/util/symbol-elf.c > @@ -862,6 +862,14 @@ int dso__load_sym(struct dso *dso, struct map *map, > !strcmp(elf_name, "$t")) > continue; > } > + /* Reject Aarch64 ELF "mapping symbols": these aren't unique and > + * don't identify functions, so will confuse the profile > + * output: */ > + if (ehdr.e_machine == EM_AARCH64) { > + if (!strcmp(elf_name, "$x") || > + !strcmp(elf_name, "$d")) > + continue; > + }
Do we need to skip $x.* and $d.* too? I doubt GCC generates them, but they are permitted by the ELF ABI.
Will
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