Messages in this thread Patch in this message | | | Subject | [PATCH perf/core v2 5/5] perf probe: Allow weak symbols to be probed | From | Masami Hiramatsu <> | Date | Fri, 06 Mar 2015 16:31:29 +0900 |
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From: Namhyung Kim <namhyung@kernel.org>
It currently prevents adding probes in weak symbols. But there're cases that given name is an only weak symbol so that we cannot add probe.
$ perf probe -x /usr/lib/libc.so.6 -a calloc Failed to find symbol calloc in /usr/lib/libc-2.21.so Error: Failed to add events.
$ nm /usr/lib/libc.so.6 | grep calloc 000000000007b1f0 t __calloc 000000000007b1f0 T __libc_calloc 000000000007b1f0 W calloc
This change will result in duplicate probes when strong and weak symbols co-exist in a binary. But I think it's not a big problem since probes at the weak symbol will never be hit anyway.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/util/probe-event.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index c379ea0..f9c1e53 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -309,10 +309,8 @@ static int find_alternative_probe_point(struct debuginfo *dinfo, /* Find the address of given function */ map__for_each_symbol_by_name(map, pp->function, sym) { - if (sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) { - address = sym->start; - break; - } + address = sym->start; + break; } if (!address) { ret = -ENOENT; @@ -2484,8 +2482,7 @@ static int find_probe_functions(struct map *map, char *name) struct symbol *sym; map__for_each_symbol_by_name(map, name, sym) { - if (sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) - found++; + found++; } return found; @@ -2845,8 +2842,7 @@ static struct strfilter *available_func_filter; static int filter_available_functions(struct map *map __maybe_unused, struct symbol *sym) { - if ((sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) && - strfilter__compare(available_func_filter, sym->name)) + if (strfilter__compare(available_func_filter, sym->name)) return 0; return 1; }
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