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@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1440586666-235233-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 6c7e538c9b8bf6cd10834836caea61c40ae8dd7e..f7bacbb9886598fad801920cf967bcff76ccd69a 100644 (file)
--- 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;