perf tests: Decompress kernel module before objdump

[ Upstream commit 94df1040b1e6aacd8dec0ba3c61d7e77cd695f26 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index ff5bc6363a79de05084aca11ec856f468ce9903d..150334064071f792c1ccc672e030d20cc897b926 100644 (file)
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -224,6 +224,8 @@ 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);
@@ -284,9 +286,25 @@ 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