Commit-ID: 76c588f1f6b560c510953b390bc0a26c27cbfbd0
Gitweb: http://git.kernel.org/tip/76c588f1f6b560c510953b390bc0a26c27cbfbd0
Author: He Kuang <hekuang@xxxxxxxxxx>
AuthorDate: Tue, 17 May 2016 09:04:54 +0000
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 23 Jun 2016 10:25:58 -0300
perf tools: Find right DSO taking into account if binary is 32 or 64-bit
There's a problem in machine__findnew_vdso(), vdso buildid generated by a
32-bit machine stores it with the name 'vdso', but when processing buildid on a
64-bit machine with the same 'perf.data', perf will search for vdso named as
'vdso32' and get failed.
This patch tries to find the existing dsos in machine->dsos by thread dso_type.
64-bit thread tries to find vdso with name 'vdso', because all 64-bit vdso is
named as that. 32-bit thread first tries to find vdso with name 'vdso32' if
this thread was run on 64-bit machine, if failed, then it tries 'vdso' which
indicates that the thread was run on 32-bit machine when recording.
Committer note:
Additional explanation by Adrian Hunter:
We match maps to builds ids using the file name - consider
machine__findnew_[v]dso() called in map__new(). So in the context of a perf
data file, we consider the file name to be unique.
A vdso map does not have a file name - all we know is that it is vdso. We look
at the thread to tell if it is 32-bit, 64-bit or x32. Then we need to get the
build id which has been recorded using short name "[vdso]" or "[vdso32]" or
"[vdsox32]".
The problem is that on a 32-bit machine, we use the name "[vdso]". If you take
a 32-bit perf data file to a 64-bit machine, it gets hard to figure out if
"[vdso]" is 32-bit or 64-bit.
This patch solves that problem.
----
This also merges a followup patch fixing a problem introduced by the
original submission of this patch, that would crash 'perf record' when
recording samples for a 32-bit app on a 64-bit system.
Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ekaterina Tumanova <tumanova@xxxxxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1463475894-163531-1-git-send-email-hekuang@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1466578626-92406-6-git-send-email-hekuang@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/vdso.c | 40 +++++++++++++++++++++++++++++++++++++---
1 file changed, 37 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
index 44d440d..7bdcad4 100644
--- a/tools/perf/util/vdso.c
+++ b/tools/perf/util/vdso.c
@@ -134,8 +134,6 @@ static struct dso *__machine__addnew_vdso(struct machine *machine, const char *s
return dso;
}
-#if BITS_PER_LONG == 64
-
static enum dso_type machine__thread_dso_type(struct machine *machine,
struct thread *thread)
{
@@ -156,6 +154,8 @@ static enum dso_type machine__thread_dso_type(struct machine *machine,
return dso_type;
}
+#if BITS_PER_LONG == 64
+
static int vdso__do_copy_compat(FILE *f, int fd)
{
char buf[4096];
@@ -283,8 +283,38 @@ static int __machine__findnew_vdso_compat(struct machine *machine,
#endif
+static struct dso *machine__find_vdso(struct machine *machine,
+ struct thread *thread)
+{
+ struct dso *dso = NULL;
+ enum dso_type dso_type;
+
+ dso_type = machine__thread_dso_type(machine, thread);
+ switch (dso_type) {
+ case DSO__TYPE_32BIT:
+ dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO32, true);
+ if (!dso) {
+ dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO,
+ true);
+ if (dso && dso_type != dso__type(dso, machine))
+ dso = NULL;
+ }
+ break;
+ case DSO__TYPE_X32BIT:
+ dso = __dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true);
+ break;
+ case DSO__TYPE_64BIT:
+ case DSO__TYPE_UNKNOWN:
+ default:
+ dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
+ break;
+ }
+
+ return dso;
+}
+
struct dso *machine__findnew_vdso(struct machine *machine,
- struct thread *thread __maybe_unused)
+ struct thread *thread)
{
struct vdso_info *vdso_info;
struct dso *dso = NULL;
@@ -297,6 +327,10 @@ struct dso *machine__findnew_vdso(struct machine *machine,
if (!vdso_info)
goto out_unlock;
+ dso = machine__find_vdso(machine, thread);
+ if (dso)
+ goto out_unlock;
+
#if BITS_PER_LONG == 64
if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
goto out_unlock;
--
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