summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/vdso.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--tools/perf/util/vdso.c363
1 files changed, 363 insertions, 0 deletions
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
new file mode 100644
index 000000000..43beb1696
--- /dev/null
+++ b/tools/perf/util/vdso.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <linux/kernel.h>
+
+#include "vdso.h"
+#include "dso.h"
+#include <internal/lib.h>
+#include "map.h"
+#include "symbol.h"
+#include "machine.h"
+#include "thread.h"
+#include "linux/string.h"
+#include <linux/zalloc.h>
+#include "debug.h"
+
+/*
+ * Include definition of find_map() also used in perf-read-vdso.c for
+ * building perf-read-vdso32 and perf-read-vdsox32.
+ */
+#include "find-map.c"
+
+#define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
+
+struct vdso_file {
+ bool found;
+ 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)
+{
+ static const struct vdso_info vdso_info_init = {
+ .vdso = {
+ .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));
+}
+
+static char *get_file(struct vdso_file *vdso_file)
+{
+ char *vdso = NULL;
+ char *buf = NULL;
+ void *start, *end;
+ size_t size;
+ int fd;
+
+ if (vdso_file->found)
+ return vdso_file->temp_file_name;
+
+ if (vdso_file->error || find_map(&start, &end, VDSO__MAP_NAME))
+ return NULL;
+
+ size = end - start;
+
+ buf = memdup(start, size);
+ if (!buf)
+ return NULL;
+
+ fd = mkstemp(vdso_file->temp_file_name);
+ if (fd < 0)
+ goto out;
+
+ if (size == (size_t) write(fd, buf, size))
+ vdso = vdso_file->temp_file_name;
+
+ close(fd);
+
+ out:
+ free(buf);
+
+ vdso_file->found = (vdso != NULL);
+ vdso_file->error = !vdso_file->found;
+ return vdso;
+}
+
+void machine__exit_vdso(struct machine *machine)
+{
+ struct vdso_info *vdso_info = machine->vdso_info;
+
+ if (!vdso_info)
+ return;
+
+ 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);
+}
+
+static struct dso *__machine__addnew_vdso(struct machine *machine, const char *short_name,
+ const char *long_name)
+{
+ struct dso *dso;
+
+ dso = dso__new(short_name);
+ if (dso != NULL) {
+ __dsos__add(&machine->dsos, dso);
+ dso__set_long_name(dso, long_name, false);
+ /* Put dso here because __dsos_add already got it */
+ dso__put(dso);
+ }
+
+ return dso;
+}
+
+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;
+
+ maps__for_each_entry(thread->maps, map) {
+ struct dso *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;
+}
+
+#if BITS_PER_LONG == 64
+
+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 *__machine__findnew_compat(struct machine *machine,
+ struct vdso_file *vdso_file)
+{
+ const char *file_name;
+ struct dso *dso;
+
+ dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
+ if (dso)
+ goto out;
+
+ file_name = vdso__get_compat_file(vdso_file);
+ if (!file_name)
+ goto out;
+
+ dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
+out:
+ return dso;
+}
+
+static int __machine__findnew_vdso_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);
+
+#ifndef HAVE_PERF_READ_VDSO32
+ if (dso_type == DSO__TYPE_32BIT)
+ return 0;
+#endif
+#ifndef HAVE_PERF_READ_VDSOX32
+ if (dso_type == DSO__TYPE_X32BIT)
+ return 0;
+#endif
+
+ switch (dso_type) {
+ case DSO__TYPE_32BIT:
+ *dso = __machine__findnew_compat(machine, &vdso_info->vdso32);
+ return 1;
+ case DSO__TYPE_X32BIT:
+ *dso = __machine__findnew_compat(machine, &vdso_info->vdsox32);
+ return 1;
+ case DSO__TYPE_UNKNOWN:
+ case DSO__TYPE_64BIT:
+ default:
+ return 0;
+ }
+}
+
+#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)
+{
+ struct vdso_info *vdso_info;
+ struct dso *dso = NULL;
+
+ down_write(&machine->dsos.lock);
+ if (!machine->vdso_info)
+ machine->vdso_info = vdso_info__new();
+
+ vdso_info = machine->vdso_info;
+ 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;
+#endif
+
+ dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
+ if (!dso) {
+ char *file;
+
+ file = get_file(&vdso_info->vdso);
+ if (file)
+ dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
+ }
+
+out_unlock:
+ dso__get(dso);
+ up_write(&machine->dsos.lock);
+ return dso;
+}
+
+bool dso__is_vdso(struct dso *dso)
+{
+ return !strcmp(dso->short_name, DSO__NAME_VDSO) ||
+ !strcmp(dso->short_name, DSO__NAME_VDSO32) ||
+ !strcmp(dso->short_name, DSO__NAME_VDSOX32);
+}