path: root/tools
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authorNamhyung Kim <namhyung@kernel.org>2017-05-31 21:01:03 +0900
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-06-05 14:16:49 -0300
commit1deec1bd96ccd8beb04d2112a6d12fe20505c3a6 (patch)
tree3507c8245a62de0f17bcc689d0caf94eea821d42 /tools
parent918c7b062a0f9198d9503cfece0210c1743c0f88 (diff)
perf header: Set proper module name when build-id event found
When perf processes build-id event, it creates DSOs with the build-id. But it didn't set the module short name (like '[module-name]') so when processing a kernel mmap event of the module, it cannot found the DSO as it only checks the short names. That leads for perf to create a same DSO without the build-id info and it'll lookup the system path even if the DSO is already in the build-id cache. After kernel was updated, perf cannot find the DSO and cannot show symbols in it anymore. You can see this if you have an old data file (w/ old kernel version): $ perf report -i perf.data.old -v |& grep scsi_mod build id event received for /lib/modules/3.19.2-1-ARCH/kernel/drivers/scsi/scsi_mod.ko.gz : cafe1ce6ca13a98a5d9ed3425cde249e57a27fc1 Failed to open /lib/modules/3.19.2-1-ARCH/kernel/drivers/scsi/scsi_mod.ko.gz, continuing without symbols ... The second message didn't show the build-id. With this patch: $ perf report -i perf.data.old -v |& grep scsi_mod build id event received for /lib/modules/3.19.2-1-ARCH/kernel/drivers/scsi/scsi_mod.ko.gz: cafe1ce6ca13a98a5d9ed3425cde249e57a27fc1 /lib/modules/3.19.2-1-ARCH/kernel/drivers/scsi/scsi_mod.ko.gz with build id cafe1ce6ca13a98a5d9ed3425cde249e57a27fc1 not found, continuing without symbols ... Now it shows the build-id but still cannot load the symbol table. This is a different problem which will be fixed in the next patch. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170531120105.21731-1-namhyung@kernel.org [ Fix the build on older compilers (debian <= 8, fedora <= 21, etc) wrt kmod_path var init ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
1 files changed, 10 insertions, 2 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 314a07151fb7..c40a4d8acf8b 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1469,8 +1469,16 @@ static int __event_process_build_id(struct build_id_event *bev,
dso__set_build_id(dso, &bev->build_id);
- if (!is_kernel_module(filename, cpumode))
- dso->kernel = dso_type;
+ if (dso_type != DSO_TYPE_USER) {
+ struct kmod_path m = { .name = NULL, };
+ if (!kmod_path__parse_name(&m, filename) && m.kmod)
+ dso__set_short_name(dso, strdup(m.name), true);
+ else
+ dso->kernel = dso_type;
+ free(m.name);
+ }
build_id__sprintf(dso->build_id, sizeof(dso->build_id),

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