Commit-ID: fd786fac78affe4a005065bc2b6f90d8f8953961
Gitweb: http://git.kernel.org/tip/fd786fac78affe4a005065bc2b6f90d8f8953961
Author: Wang Nan <wangnan0@xxxxxxxxxx>
AuthorDate: Fri, 29 Jan 2016 17:40:51 +0000
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 29 Jan 2016 17:16:25 -0300
perf buildid: Fix cpumode of buildid event
There is a nasty confusion that, for kernel module, dso->kernel is not
necessary to be DSO_TYPE_KERNEL or DSO_TYPE_GUEST_KERNEL. These two
enums are for vmlinux. See thread [1]. We tried to fix this part but it
is costy.
Code machine__write_buildid_table() is another unfortunate function fall
into this trap that, when issuing buildid event for a kernel module,
cpumode it gives to the event is PERF_RECORD_MISC_USER, not
PERF_RECORD_MISC_KERNEL.
However, even with this bug, most of the time it doesn't causes real
problem. I find this issue when trying to use a perf before commit
3d39ac538629 ("perf machine: No need to have two DSOs lists") to parse a
perf.data generated by newest perf.
[1] https://lkml.org/lkml/2015/9/21/908
Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1454089251-203152-1-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/build-id.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 6a7e273..b28100e 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -211,6 +211,7 @@ static int machine__write_buildid_table(struct machine *machine, int fd)
dsos__for_each_with_build_id(pos, &machine->dsos.head) {
const char *name;
size_t name_len;
+ bool in_kernel = false;
if (!pos->hit)
continue;
@@ -227,8 +228,11 @@ static int machine__write_buildid_table(struct machine *machine, int fd)
name_len = pos->long_name_len + 1;
}
+ in_kernel = pos->kernel ||
+ is_kernel_module(name,
+ PERF_RECORD_MISC_CPUMODE_UNKNOWN);
err = write_buildid(name, name_len, pos->build_id, machine->pid,
- pos->kernel ? kmisc : umisc, fd);
+ in_kernel ? kmisc : umisc, fd);
if (err)
break;
}
--
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