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authorWang Nan <wangnan0@huawei.com>2016-02-05 17:01:27 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-02-12 16:54:47 +0300
commite7ee404757609067c8f261d90251f1e96459c535 (patch)
tree257a6d1755448ed932f7fff60924d7ae9e17ae8e /tools/perf/util/symbol.c
parentc7ac24178c50a01f14eebcddf5c7b7a2e54676cc (diff)
downloadlinux-e7ee404757609067c8f261d90251f1e96459c535.tar.xz
perf symbols: Fix symbols searching for module in buildid-cache
Before this patch, if a sample is triggered inside a module not in /lib/modules/`uname -r`/, even if the module is in buildid-cache, 'perf report' will still be unable to find the correct symbol. For example: # rm -rf ~/.debug/ # perf buildid-cache -a ./mymodule.ko # perf probe -m ./mymodule.ko -a get_mymodule_val Added new event: probe:get_mymodule_val (on get_mymodule_val in mymodule) You can now use it in all perf tools, such as: perf record -e probe:get_mymodule_val -aR sleep 1 # perf record -e probe:get_mymodule_val cat /proc/mymodule mymodule:3 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.011 MB perf.data (1 samples) ] # perf report --stdio [SNIP] # # Overhead Command Shared Object Symbol # ........ ....... ................ ...................... # 100.00% cat [mymodule] [k] 0x0000000000000001 # perf report -vvvv --stdio dso__load_sym: adjusting symbol: st_value: 0 sh_addr: 0 sh_offset: 0x70 symbol__new: get_mymodule_val 0x70-0x8a [SNIP] This is caused by dso__load() -> dso__load_sym(). In dso__load(), kmod is true only when its file is found in some well know directories. All files loaded from buildid-cache are treated as user programs. Following dso__load_sym() set map->pgoff incorrectly. This patch gives kernel modules in buildid-cache a chance to adjust value of kmod. After dso__load() get the type of symbols, if it is buildid, check the last 3 chars of original filename against '.ko', and adjust the value of kmod if the file is a kernel module. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Cody P Schafer <dev@codyps.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kirill Smelkov <kirr@nexedi.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1454680939-24963-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/symbol.c')
-rw-r--r--tools/perf/util/symbol.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 90cedfa30e43..e7588dc91518 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1529,6 +1529,10 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
if (!runtime_ss && syms_ss)
runtime_ss = syms_ss;
+ if (syms_ss && syms_ss->type == DSO_BINARY_TYPE__BUILD_ID_CACHE)
+ if (dso__build_id_is_kmod(dso, name, PATH_MAX))
+ kmod = true;
+
if (syms_ss)
ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, kmod);
else