From: Masami Hiramatsu <[email protected]>

Fix to get correctly unmapped symbol address on kernel.  This allows us
to probe on syscall symbols which are aliases of SyS_ functions with
using debuginfo.

Without this fix:
  ----
  # ./perf probe -a sys_write
  Failed to find debug information for address 3b0100
  Probe point 'sys_write' not found.
    Error: Failed to add events.
  ----
The address 0x3b0100 is a mapped address, and not usable
in debuginfo.

With this fix:
  ----
  # ./perf probe -a sys_write
  Added new event:
    probe:sys_write      (on sys_write)

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

          perf record -e probe:sys_write -aR sleep 1
  ----

Signed-off-by: Masami Hiramatsu <[email protected]>
Cc: He Kuang <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/probe-event.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 6b95985db5b0..8feac0774c41 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -310,7 +310,10 @@ static int find_alternative_probe_point(struct debuginfo 
*dinfo,
 
        /* Find the address of given function */
        map__for_each_symbol_by_name(map, pp->function, sym) {
-               address = sym->start;
+               if (uprobes)
+                       address = sym->start;
+               else
+                       address = map->unmap_ip(map, sym->start);
                break;
        }
        if (!address) {
-- 
1.9.3

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