[03/11] perf probe: Adjust map->reloc offset when finding kernel symbol from map

Message ID 1470758494-32127-4-git-send-email-acme@kernel.org
State New
Headers show

Commit Message

Arnaldo Carvalho de Melo Aug. 9, 2016, 4:01 p.m.
From: Masami Hiramatsu <masami.hiramatsu@linaro.org>


Adjust map->reloc offset for the unmapped address when finding
alternative symbol address from map, because KASLR can relocate the
kernel symbol address.

The same adjustment has been done when finding appropriate kernel symbol
address from map which was introduced by commit f90acac75713 ("perf
probe: Find given address from offline dwarf")

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>

Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160806192948.e366f3fbc4b194de600f8326@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

---
 tools/perf/util/probe-event.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.7.4

Patch

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 953dc1ab2ed7..d5ccb656fd81 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -385,7 +385,7 @@  static int find_alternative_probe_point(struct debuginfo *dinfo,
 		if (uprobes)
 			address = sym->start;
 		else
-			address = map->unmap_ip(map, sym->start);
+			address = map->unmap_ip(map, sym->start) - map->reloc;
 		break;
 	}
 	if (!address) {