Patch "perf tests: Decompress kernel module before objdump" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

perf tests: Decompress kernel module before objdump

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
perf-tests-decompress-kernel-module-before-objdump.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Namhyung Kim <[email protected]>
Date: Thu, 8 Jun 2017 16:31:07 +0900
Subject: perf tests: Decompress kernel module before objdump

From: Namhyung Kim <[email protected]>

[ 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.

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

@@ -182,6 +182,8 @@ static int read_object_code(u64 addr, si
 	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, si
 		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

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/perf-trace-add-mmap-alias-for-s390.patch queue-4.4/perf-report-ensure-the-perf-dso-mapping-matches-what-libdw-sees.patch queue-4.4/perf-tools-fix-copyfile_offset-update-of-output-offset.patch queue-4.4/perf-tests-decompress-kernel-module-before-objdump.patch queue-4.4/perf-header-set-proper-module-name-when-build-id-event-found.patch