perf symbols: Ignore mapping symbols on aarch64

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 <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Acked-by: Will Deacon <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Anton Blanchard <[email protected]>
Cc: Avi Kivity <[email protected]>
Cc: Dave Martin <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: [email protected]
Cc: Masami Hiramatsu <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Russell King <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index b24f9d8727a894ccae13353abad0b951ec1b0916..225eb73ee78b7f52a64feb035fcf0c2336fdc7d9 100644 (file)
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -859,10 +859,9 @@ 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;
                }