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authorAdrian Hunter <adrian.hunter@intel.com>2014-10-23 14:45:23 +0400
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-10-29 15:32:48 +0300
commitf6832e1720f5cc283703cfe9ccbfb46a3fb6f548 (patch)
tree16f0d4b4efc87d30035dd4a5340d5536d9452fa2 /tools/perf/util/vdso.c
parente477f3f01a89a8fd44031e7f2ba6ffcab037336c (diff)
downloadlinux-f6832e1720f5cc283703cfe9ccbfb46a3fb6f548.tar.xz
perf tools: Add support for 32-bit compatibility VDSOs
'perf record' post-processes the event stream to create a list of build-ids for object files for which sample events have been recorded. That results in those object files being recorded in the build-id cache. In the case of VDSO, perf tools reads it from memory and copies it into a temporary file, which as decribed above, gets added to the build-id cache. Then when the perf.data file is processed by other tools, the build-id of VDSO is listed in the perf.data file and the VDSO can be read from the build-id cache. In that case the name of the map, the short name of the DSO, and the entry in the build-id cache are all "[vdso]". However, in the 64-bit case, there also can be 32-bit compatibility VDSOs. A previous patch added programs "perf-read-vdso32" and "perf read-vdsox32". This patch uses those programs to read the correct VDSO for a thread and create a temporary file just as for the 64-bit VDSO. The map name and the entry in the build-id cache are still "[vdso]" but the DSO short name becomes "[vdso32]" and "[vdsox32]" respectively. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1414061124-26830-16-git-send-email-adrian.hunter@intel.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.c170
1 files changed, 169 insertions, 1 deletions
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
index f51390a1ed51..69daef6a17d5 100644
--- a/tools/perf/util/vdso.c
+++ b/tools/perf/util/vdso.c
@@ -12,6 +12,7 @@
#include "util.h"
#include "symbol.h"
#include "machine.h"
+#include "thread.h"
#include "linux/string.h"
#include "debug.h"
@@ -28,10 +29,15 @@ struct vdso_file {
bool error;
char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
const char *dso_name;
+ const char *read_prog;
};
struct vdso_info {
struct vdso_file vdso;
+#if BITS_PER_LONG == 64
+ struct vdso_file vdso32;
+ struct vdso_file vdsox32;
+#endif
};
static struct vdso_info *vdso_info__new(void)
@@ -41,6 +47,18 @@ static struct vdso_info *vdso_info__new(void)
.temp_file_name = VDSO__TEMP_FILE_NAME,
.dso_name = DSO__NAME_VDSO,
},
+#if BITS_PER_LONG == 64
+ .vdso32 = {
+ .temp_file_name = VDSO__TEMP_FILE_NAME,
+ .dso_name = DSO__NAME_VDSO32,
+ .read_prog = "perf-read-vdso32",
+ },
+ .vdsox32 = {
+ .temp_file_name = VDSO__TEMP_FILE_NAME,
+ .dso_name = DSO__NAME_VDSOX32,
+ .read_prog = "perf-read-vdsox32",
+ },
+#endif
};
return memdup(&vdso_info_init, sizeof(vdso_info_init));
@@ -92,6 +110,12 @@ void vdso__exit(struct machine *machine)
if (vdso_info->vdso.found)
unlink(vdso_info->vdso.temp_file_name);
+#if BITS_PER_LONG == 64
+ if (vdso_info->vdso32.found)
+ unlink(vdso_info->vdso32.temp_file_name);
+ if (vdso_info->vdsox32.found)
+ unlink(vdso_info->vdsox32.temp_file_name);
+#endif
zfree(&machine->vdso_info);
}
@@ -110,6 +134,143 @@ static struct dso *vdso__new(struct machine *machine, const char *short_name,
return dso;
}
+#if BITS_PER_LONG == 64
+
+static enum dso_type machine__thread_dso_type(struct machine *machine,
+ struct thread *thread)
+{
+ enum dso_type dso_type = DSO__TYPE_UNKNOWN;
+ struct map *map;
+ struct dso *dso;
+
+ map = map_groups__first(thread->mg, MAP__FUNCTION);
+ for (; map ; map = map_groups__next(map)) {
+ dso = map->dso;
+ if (!dso || dso->long_name[0] != '/')
+ continue;
+ dso_type = dso__type(dso, machine);
+ if (dso_type != DSO__TYPE_UNKNOWN)
+ break;
+ }
+
+ return dso_type;
+}
+
+static int vdso__do_copy_compat(FILE *f, int fd)
+{
+ char buf[4096];
+ size_t count;
+
+ while (1) {
+ count = fread(buf, 1, sizeof(buf), f);
+ if (ferror(f))
+ return -errno;
+ if (feof(f))
+ break;
+ if (count && writen(fd, buf, count) != (ssize_t)count)
+ return -errno;
+ }
+
+ return 0;
+}
+
+static int vdso__copy_compat(const char *prog, int fd)
+{
+ FILE *f;
+ int err;
+
+ f = popen(prog, "r");
+ if (!f)
+ return -errno;
+
+ err = vdso__do_copy_compat(f, fd);
+
+ if (pclose(f) == -1)
+ return -errno;
+
+ return err;
+}
+
+static int vdso__create_compat_file(const char *prog, char *temp_name)
+{
+ int fd, err;
+
+ fd = mkstemp(temp_name);
+ if (fd < 0)
+ return -errno;
+
+ err = vdso__copy_compat(prog, fd);
+
+ if (close(fd) == -1)
+ return -errno;
+
+ return err;
+}
+
+static const char *vdso__get_compat_file(struct vdso_file *vdso_file)
+{
+ int err;
+
+ if (vdso_file->found)
+ return vdso_file->temp_file_name;
+
+ if (vdso_file->error)
+ return NULL;
+
+ err = vdso__create_compat_file(vdso_file->read_prog,
+ vdso_file->temp_file_name);
+ if (err) {
+ pr_err("%s failed, error %d\n", vdso_file->read_prog, err);
+ vdso_file->error = true;
+ return NULL;
+ }
+
+ vdso_file->found = true;
+
+ return vdso_file->temp_file_name;
+}
+
+static struct dso *vdso__findnew_compat(struct machine *machine,
+ struct vdso_file *vdso_file)
+{
+ const char *file_name;
+ struct dso *dso;
+
+ dso = dsos__find(&machine->user_dsos, vdso_file->dso_name, true);
+ if (dso)
+ return dso;
+
+ file_name = vdso__get_compat_file(vdso_file);
+ if (!file_name)
+ return NULL;
+
+ return vdso__new(machine, vdso_file->dso_name, file_name);
+}
+
+static int vdso__dso_findnew_compat(struct machine *machine,
+ struct thread *thread,
+ struct vdso_info *vdso_info,
+ struct dso **dso)
+{
+ enum dso_type dso_type;
+
+ dso_type = machine__thread_dso_type(machine, thread);
+ switch (dso_type) {
+ case DSO__TYPE_32BIT:
+ *dso = vdso__findnew_compat(machine, &vdso_info->vdso32);
+ return 1;
+ case DSO__TYPE_X32BIT:
+ *dso = vdso__findnew_compat(machine, &vdso_info->vdsox32);
+ return 1;
+ case DSO__TYPE_UNKNOWN:
+ case DSO__TYPE_64BIT:
+ default:
+ return 0;
+ }
+}
+
+#endif
+
struct dso *vdso__dso_findnew(struct machine *machine,
struct thread *thread __maybe_unused)
{
@@ -123,6 +284,11 @@ struct dso *vdso__dso_findnew(struct machine *machine,
if (!vdso_info)
return NULL;
+#if BITS_PER_LONG == 64
+ if (vdso__dso_findnew_compat(machine, thread, vdso_info, &dso))
+ return dso;
+#endif
+
dso = dsos__find(&machine->user_dsos, DSO__NAME_VDSO, true);
if (!dso) {
char *file;
@@ -139,5 +305,7 @@ struct dso *vdso__dso_findnew(struct machine *machine,
bool dso__is_vdso(struct dso *dso)
{
- return !strcmp(dso->short_name, DSO__NAME_VDSO);
+ return !strcmp(dso->short_name, DSO__NAME_VDSO) ||
+ !strcmp(dso->short_name, DSO__NAME_VDSO32) ||
+ !strcmp(dso->short_name, DSO__NAME_VDSOX32);
}