(2015/03/04 22:52), Namhyung Kim wrote:
> 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.
>
> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
> Signed-off-by: Namhyung Kim <namhy...@kernel.org>
> ---
> tools/perf/util/probe-event.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 1c570c2fa7cc..12b7d018106e 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2339,8 +2339,7 @@ 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++;
> }
Ah, I've found this is the magic...
Here, we need another fix on my series.
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 22392b06..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 *d
/* 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;
-------
With this fix, I could get variables on waitpid and calloc.
-----
# ./perf probe -x /lib64/libc-2.17.so -V waitpid
Available variables at waitpid
@<__libc_waitpid+0>
__pid_t pid
int oldtype
int options
int* stat_loc
-----
I'll update and include it my series.
Thank you!
>
> return found;
> @@ -2708,8 +2707,7 @@ 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;
> }
>
--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu...@hitachi.com
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