[tip:perf/core] perf probe: Fix list result when symbol can' t be found

[tip-bot for Wang Nan]

Commit-ID:  614e2fdbd79b47ddf63a1ccd3f2343e98c3077fb
Gitweb:     http://git.kernel.org/tip/614e2fdbd79b47ddf63a1ccd3f2343e98c3077fb
Author:     Wang Nan <wangnan0@xxxxxxxxxx>
AuthorDate: Wed, 26 Aug 2015 10:57:42 +0000
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 26 Aug 2015 10:36:04 -0300

perf probe: Fix list result when symbol can't be found

'perf probe -l' reports error if it is unable find symbol through
address. Here is an example.

  # echo 'p:probe_libc/abs_5 /lib64/libc.so.6:0x5' >
          /sys/kernel/debug/tracing/uprobe_events
  # cat /sys/kernel/debug/tracing/uprobe_events
   p:probe_libc/abs_5 /lib64/libc.so.6:0x0000000000000005
  # perf probe -l
    Error: Failed to show event list

Also, this situation triggers a logical inconsistency in
convert_to_perf_probe_point() that, it returns ENOMEM but actually it
never try strdup().

This patch removes !tp->module && !is_kprobe condition, so it always
uses address to build function name if symbol not found.

Test result:

  # perf probe -l
    probe_libc:abs_5     (on 0x5 in /lib64/libc.so.6)

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1440586666-235233-4-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/probe-event.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 6c7e538..f7bacbb 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1866,7 +1866,7 @@ static int convert_to_perf_probe_point(struct probe_trace_point *tp,
 	if (tp->symbol) {
 		pp->function = strdup(tp->symbol);
 		pp->offset = tp->offset;
-	} else if (!tp->module && !is_kprobe) {
+	} else {
 		ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address);
 		if (ret < 0)
 			return ret;
--
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