commit 7525a238be8f46617cdda29d1be5b85ffe3b042d
Author: Namhyung Kim <namhyung@kernel.org>
Date:   Thu Jun 8 16:31:07 2017 +0900

    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 ff5bc6363a79..150334064071 100644
--- 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