From: Arnaldo Carvalho de Melo on
From: Dave Martin <dave.martin(a)linaro.org>

ARM ELF files use symbols with special names $a, $t, $d to identify regions of
ARM code, Thumb code and data within code sections. This can cause confusing
output from the perf tools, especially for partially stripped binaries, or
binaries containing user-added zero-sized symbols (which may occur in
hand-written assembler which hasn't been fully annotated with .size
directives).

This patch filters out these symbols at load time.

LKML-Reference: <1281352878-8735-2-git-send-email-dave.martin(a)linaro.org>
Signed-off-by: Dave Martin <dave.martin(a)linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme(a)redhat.com>
---
tools/perf/util/symbol.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index b6f5970..1a36773 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1079,6 +1079,16 @@ static int dso__load_sym(struct dso *self, struct map *map, const char *name,
if (!is_label && !elf_sym__is_a(&sym, map->type))
continue;

+ /* 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"))
+ continue;
+ }
+
if (opdsec && sym.st_shndx == opdidx) {
u32 offset = sym.st_value - opdshdr.sh_addr;
u64 *opd = opddata->d_buf + offset;
--
1.6.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/