perf tests: Decompress kernel module before objdump

If a kernel modules is compressed, it should be decompressed before
running objdump to parse binary data correctly.  This fixes a failure of
object code reading test for me.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index 1f14e7612cbb..94b7c7b02bde 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -229,6 +229,8 @@ static int read_object_code(u64 addr, size_t len, u8 cpumode,
         unsigned char buf2[BUFSZ];
         size_t ret_len;
         u64 objdump_addr;
+        const char *objdump_name;
+        char decomp_name[KMOD_DECOMP_LEN];
         int ret;
 
         pr_debug("Reading object code for memory address: %#"PRIx64"\n", addr);
@@ -289,9 +291,25 @@ static int read_object_code(u64 addr, size_t len, u8 cpumode,
                 state->done[state->done_cnt++] = al.map->start;
         }
 
+        objdump_name = al.map->dso->long_name;
+        if (dso__needs_decompress(al.map->dso)) {
+                if (dso__decompress_kmodule_path(al.map->dso, objdump_name,
+                                                 decomp_name,
+                                                 sizeof(decomp_name)) < 0) {
+                        pr_debug("decompression failed\n");
+                        return -1;
+                }
+
+                objdump_name = decomp_name;
+        }
+
         /* Read the object code using objdump */
         objdump_addr = map__rip_2objdump(al.map, al.addr);
-        ret = read_via_objdump(al.map->dso->long_name, objdump_addr, buf2, len);
+        ret = read_via_objdump(objdump_name, objdump_addr, buf2, len);
+
+        if (dso__needs_decompress(al.map->dso))
+                unlink(objdump_name);
+
         if (ret > 0) {
                 /*
                  * The kernel maps are inaccurate - assume objdump is right in