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authorNamhyung Kim <namhyung@kernel.org>2025-01-02 12:32:51 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-02-08 10:01:37 +0100
commitfd19cdc53927613603b0239a048f6e0b40e0f505 (patch)
tree77cdbe7c344ed39388a57d89686a762a7b8a4577
parentfaac25d7a51a3bdba7bb8dd6d51bae7f17dbbe2d (diff)
perf symbol: Prefer non-label symbols with same address
[ Upstream commit 8c2eafbbfd782d6ad270ca2de21b529ac57de0f4 ] When there are more than one symbols at the same address, it needs to choose which one is better. In choose_best_symbol() it didn't check the type of symbols. It's possible to have labels in other symbols and in that case, it would be better to pick the actual symbol over the labels. To minimize the possible impact on other symbols, I only check NOTYPE symbols specifically. $ readelf -sW vmlinux | grep -e __do_softirq -e __softirqentry_text_start 105089: ffffffff82000000 814 FUNC GLOBAL DEFAULT 1 __do_softirq 111954: ffffffff82000000 0 NOTYPE GLOBAL DEFAULT 1 __softirqentry_text_start The commit 77b004f4c5c3c90b tried to do the same by not giving the size to the label symbols but it seems there's some label-only symbols in asm code. Let's restore the original code and choose the right symbol using type of the symbols. Fixes: 77b004f4c5c3c90b ("perf symbol: Do not fixup end address of labels") Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Ian Rogers <irogers@google.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Link: http://lore.kernel.org/lkml/Z3b-DqBMnNb4ucEm@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--tools/perf/util/symbol.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 0037f1163919..49b08adc6ee3 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -154,6 +154,13 @@ static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
else if ((a == 0) && (b > 0))
return SYMBOL_B;
+ if (syma->type != symb->type) {
+ if (syma->type == STT_NOTYPE)
+ return SYMBOL_B;
+ if (symb->type == STT_NOTYPE)
+ return SYMBOL_A;
+ }
+
/* Prefer a non weak symbol over a weak one */
a = syma->binding == STB_WEAK;
b = symb->binding == STB_WEAK;
@@ -257,7 +264,7 @@ void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
* like in:
* ffffffffc1937000 T hdmi_driver_init [snd_hda_codec_hdmi]
*/
- if (prev->end == prev->start && prev->type != STT_NOTYPE) {
+ if (prev->end == prev->start) {
const char *prev_mod;
const char *curr_mod;