[PATCH AUTOSEL for 4.4 140/167] perf tests: Decompress kernel module before objdump

Sasha Levin
2018-03-19T17:07:11Z

From: Namhyung Kim <namhyung@kernel.org>

[ 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>
---
tools/perf/tests/code-reading.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index a767a6400c5c..6ea4fcfaab36 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -182,6 +182,8 @@ 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);
@@ -242,9 +244,25 @@ 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
--
2.14.1