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authorHe Kuang <hekuang@huawei.com>2016-05-17 09:04:54 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-06-23 10:25:58 -0300
commit76c588f1f6b560c510953b390bc0a26c27cbfbd0 (patch)
tree14a955a4e78daa430957441ba5401bcd6c48f3e8 /tools/perf/util/vdso.c
parent41840d211c518e6af6e327b03e09323824e563bf (diff)
downloadlinux-76c588f1f6b560c510953b390bc0a26c27cbfbd0.tar.bz2
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@huawei.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1463475894-163531-1-git-send-email-hekuang@huawei.com Link: http://lkml.kernel.org/r/1466578626-92406-6-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/vdso.c')
-rw-r--r--tools/perf/util/vdso.c40
1 files changed, 37 insertions, 3 deletions
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
index 44d440da15dc..7bdcad484225 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;