[PATCH V3 1/2] perf symbols: Ignore mapping symbols on aarch64

[Namhyung Kim]

On Mon, Jan 26, 2015 at 10:34:01PM -0800, Victor Kamensky wrote:
> Aarch64 ELF files use mapping symbols with special names $x, $d
> to identify regions of Aarch64 code (see Aarch64 ELF ABI - "ARM
> IHI 0056B", section "4.5.4 Mapping symbols").
> 
> The patch filters out these symbols at load time, similar to
> "696b97a perf symbols: Ignore mapping symbols on ARM" changes
> done for ARM before V8.
> 
> Also added handling of mapping symbols that has format
> "$d.<any>" and similar for both cases.
> 
> Note we are not making difference between EM_ARM and
> EM_AARCH64 mapping symbols instead code handles superset
> of both.
> 
> Signed-off-by: Victor Kamensky <victor.kamensky at linaro.org>
> Acked-by: Will Deacon <will.deacon at arm.com>
> Cc: Peter Zijlstra <a.p.zijlstra at chello.nl>
> Cc: Paul Mackerras <paulus at samba.org>
> Cc: Ingo Molnar <mingo at redhat.com>
> Cc: Arnaldo Carvalho de Melo <acme at kernel.org>
> Cc: Adrian Hunter <adrian.hunter at intel.com>
> Cc: Jiri Olsa <jolsa at redhat.com>
> Cc: Avi Kivity <avi at cloudius-systems.com>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt at hitachi.com>
> Cc: Anton Blanchard <anton at samba.org>
> Cc: David Ahern <dsahern at gmail.com>
> Cc: Will Deacon <will.deacon at arm.com>
> Cc: Russell King <linux at arm.linux.org.uk>
> Cc: Dave Martin <Dave.Martin at arm.com>

Acked-by: Namhyung Kim <namhyung at kernel.org>

Thanks,
Namhyung


> ---
>  tools/perf/util/symbol-elf.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index 06fcd1b..8fc6e2f 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -856,10 +856,9 @@ int dso__load_sym(struct dso *dso, struct map *map,
>  		/* Reject ARM ELF "mapping symbols": these aren't unique and
>  		 * don't identify functions, so will confuse the profile
>  		 * output: */
> -		if (ehdr.e_machine == EM_ARM) {
> -			if (!strcmp(elf_name, "$a") ||
> -			    !strcmp(elf_name, "$d") ||
> -			    !strcmp(elf_name, "$t"))
> +		if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
> +			if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
> +			    && (elf_name[2] == '\0' || elf_name[2] == '.'))
>  				continue;
>  		}
>  
> -- 
> 1.9.3
> 
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