(2015/01/15 8:48), Namhyung Kim wrote:
> The find_probe_trace_events_from_map() searches matching symbol from a
> map (so from a backing dso). For uprobes, it'll create a new map (and
> dso) and loads it using a filter. It's a little bit inefficient in that
> it'll read out the symbol table everytime but works well anyway.
>
> For kprobes however, it'll reuse existing kernel map which might be
> loaded before. In this case map__load() just returns with no result.
> It makes kprobes always failed to find symbol even if it exists in the
> map (dso).
>
> To fix it, use map__find_symbol_by_name_from() instead. It'll load a
> map with full symbols and sorts them by name. It needs to search sibing
> nodes since there can be multiple (local) symbols with same name.
>
Looks good to me :)
Acked-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Thank you!
> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
> Signed-off-by: Namhyung Kim <namhy...@kernel.org>
> ---
> tools/perf/util/probe-event.c | 31 ++++++++++++++-----------------
> 1 file changed, 14 insertions(+), 17 deletions(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 94a717bf007d..3cfad9c74faf 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2193,18 +2193,17 @@ static int __add_probe_trace_events(struct
> perf_probe_event *pev,
> return ret;
> }
>
> -static char *looking_function_name;
> -static int num_matched_functions;
> -
> -static int probe_function_filter(struct map *map __maybe_unused,
> - struct symbol *sym)
> +static int find_probe_functions(struct map *map, char *name)
> {
> - if ((sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL) &&
> - strcmp(looking_function_name, sym->name) == 0) {
> - num_matched_functions++;
> - return 0;
> + struct symbol *sym = NULL;
> + int found = 0;
> +
> + while ((sym = map__find_symbol_by_name_from(map, name, NULL, sym))) {
> + if (sym->binding == STB_GLOBAL || sym->binding == STB_LOCAL)
> + found++;
> }
> - return 1;
> +
> + return found;
> }
>
> #define strdup_or_goto(str, label) \
> @@ -2221,11 +2220,11 @@ static int find_probe_trace_events_from_map(struct
> perf_probe_event *pev,
> struct map *map = NULL;
> struct kmap *kmap = NULL;
> struct ref_reloc_sym *reloc_sym = NULL;
> - struct symbol *sym;
> - struct rb_node *nd;
> + struct symbol *sym = NULL;
> struct probe_trace_event *tev;
> struct perf_probe_point *pp = &pev->point;
> struct probe_trace_point *tp;
> + int num_matched_functions;
> int ret, i;
>
> /* Init maps of given executable or kernel */
> @@ -2242,10 +2241,8 @@ static int find_probe_trace_events_from_map(struct
> perf_probe_event *pev,
> * Load matched symbols: Since the different local symbols may have
> * same name but different addresses, this lists all the symbols.
> */
> - num_matched_functions = 0;
> - looking_function_name = pp->function;
> - ret = map__load(map, probe_function_filter);
> - if (ret || num_matched_functions == 0) {
> + num_matched_functions = find_probe_functions(map, pp->function);
> + if (num_matched_functions == 0) {
> pr_err("Failed to find symbol %s in %s\n", pp->function,
> target ? : "kernel");
> ret = -ENOENT;
> @@ -2275,7 +2272,7 @@ static int find_probe_trace_events_from_map(struct
> perf_probe_event *pev,
> }
>
> ret = 0;
> - map__for_each_symbol(map, sym, nd) {
> + while ((sym = map__find_symbol_by_name_from(map, pp->function, NULL,
> sym))) {
> tev = (*tevs) + ret;
> tp = &tev->point;
> if (ret == num_matched_functions) {
>
--
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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