* Masami Hiramatsu <[email protected]> [2020-07-09 17:07:01]:
> There is a case that the several same-name symbols points
> same address. In that case, perf probe returns an error.
>
> E.g.
>
> With this patch;
>
> # perf probe -x /lib64/libc-2.30.so -a "memcpy arg1=%di"
> Failed to find the location of the '%di' variable at this address.
> Perhaps it has been optimized out.
> Use -V with the --range option to show '%di' location range.
> Added new events:
> probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di)
> probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di)
>
> You can now use it in all perf tools, such as:
>
> perf record -e probe_libc:memcpy -aR sleep 1
>
>
> Reported-by: Andi Kleen <[email protected]>
> Signed-off-by: Masami Hiramatsu <[email protected]>
One small nit:
> ---
> tools/perf/util/probe-event.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index df713a5d1e26..1e95a336862c 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2968,6 +2968,15 @@ static int find_probe_trace_events_from_map(struct
> perf_probe_event *pev,
> for (j = 0; j < num_matched_functions; j++) {
> sym = syms[j];
>
> + /* There can be duplicated symbols in the map */
> + for (i = 0; i < j; i++)
> + if (sym->start == syms[i]->start) {
> + pr_debug("find duplicated symbol %s @ %lx\n",
> sym->name, sym->start);
Would "Found" sound better than "find"?
> + break;
> + }
> + if (i != j)
> + continue;
> +
Reviewed-by: Srikar Dronamraju <[email protected]>
> tev = (*tevs) + ret;
> tp = &tev->point;
> if (ret == num_matched_functions) {
>
--
Thanks and Regards
Srikar Dronamraju
