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| author | Namhyung Kim <namhyung@kernel.org> | 2017-05-31 15:01:03 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-06-05 20:16:49 +0300 |
| commit | 1deec1bd96ccd8beb04d2112a6d12fe20505c3a6 (patch) | |
| tree | 3507c8245a62de0f17bcc689d0caf94eea821d42 /tools | |
| parent | 918c7b062a0f9198d9503cfece0210c1743c0f88 (diff) | |
| download | linux-1deec1bd96ccd8beb04d2112a6d12fe20505c3a6.tar.xz | |
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')
| -rw-r--r-- | tools/perf/util/header.c | 12 |
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), sbuild_id); |