perf probe: Find versioned symbols from map

Commit d80406453ad4 ("perf symbols: Allow user probes on versioned
symbols") allows user to find default versioned symbols (with "@@") in
map. However, it did not enable normal versioned symbol (with "@") for
perf-probe.  E.g.

  =====
  # ./perf probe -x /lib64/libc-2.25.so malloc_get_state
  Failed to find symbol malloc_get_state in /usr/lib64/libc-2.25.so
    Error: Failed to add events.
  =====

This solves above issue by improving perf-probe symbol search function,
as below.

  =====
  # ./perf probe -x /lib64/libc-2.25.so malloc_get_state
  Added new event:
    probe_libc:malloc_get_state (on malloc_get_state in /usr/lib64/libc-2.25.so)

  You can now use it in all perf tools, such as:

	  perf record -e probe_libc:malloc_get_state -aR sleep 1

  # ./perf probe -l
    probe_libc:malloc_get_state (on malloc_get_state@GLIBC_2.2.5 in /usr/lib64/libc-2.25.so)
  =====

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Acked-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: bhargavb <bhargavaramudu@gmail.com>
Cc: linux-rt-users@vger.kernel.org
Link: http://lkml.kernel.org/r/151275049269.24652.1639103455496216255.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 18 insertions, 2 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index a68141d360b0..0d6c66d51939 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2801,16 +2801,32 @@ static int find_probe_functions(struct map *map, char *name,
 	int found = 0;
 	struct symbol *sym;
 	struct rb_node *tmp;
+	const char *norm, *ver;
+	char *buf = NULL;
 
 	if (map__load(map) < 0)
 		return 0;
 
 	map__for_each_symbol(map, sym, tmp) {
-		if (strglobmatch(sym->name, name)) {
+		norm = arch__normalize_symbol_name(sym->name);
+		if (!norm)
+			continue;
+
+		/* We don't care about default symbol or not */
+		ver = strchr(norm, '@');
+		if (ver) {
+			buf = strndup(norm, ver - norm);
+			if (!buf)
+				return -ENOMEM;
+			norm = buf;
+		}
+		if (strglobmatch(norm, name)) {
 			found++;
 			if (syms && found < probe_conf.max_probes)
 				syms[found - 1] = sym;
 		}
+		if (buf)
+			zfree(&buf);
 	}
 
 	return found;
@@ -2856,7 +2872,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
 	 * same name but different addresses, this lists all the symbols.
 	 */
 	num_matched_functions = find_probe_functions(map, pp->function, syms);
-	if (num_matched_functions == 0) {
+	if (num_matched_functions <= 0) {
 		pr_err("Failed to find symbol %s in %s\n", pp->function,
 			pev->target ? : "kernel");
 		ret = -ENOENT;