1 // SPDX-License-Identifier: GPL-2.0
10 #include <linux/kernel.h>
14 #include <internal/lib.h>
19 #include "linux/string.h"
20 #include <linux/zalloc.h>
24 * Include definition of find_map() also used in perf-read-vdso.c for
25 * building perf-read-vdso32 and perf-read-vdsox32.
29 #define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
34 char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
36 const char *read_prog;
40 struct vdso_file vdso;
41 #if BITS_PER_LONG == 64
42 struct vdso_file vdso32;
43 struct vdso_file vdsox32;
47 static struct vdso_info *vdso_info__new(void)
49 static const struct vdso_info vdso_info_init = {
51 .temp_file_name = VDSO__TEMP_FILE_NAME,
52 .dso_name = DSO__NAME_VDSO,
54 #if BITS_PER_LONG == 64
56 .temp_file_name = VDSO__TEMP_FILE_NAME,
57 .dso_name = DSO__NAME_VDSO32,
58 .read_prog = "perf-read-vdso32",
61 .temp_file_name = VDSO__TEMP_FILE_NAME,
62 .dso_name = DSO__NAME_VDSOX32,
63 .read_prog = "perf-read-vdsox32",
68 return memdup(&vdso_info_init, sizeof(vdso_info_init));
71 static char *get_file(struct vdso_file *vdso_file)
80 return vdso_file->temp_file_name;
82 if (vdso_file->error || find_map(&start, &end, VDSO__MAP_NAME))
87 buf = memdup(start, size);
91 fd = mkstemp(vdso_file->temp_file_name);
95 if (size == (size_t) write(fd, buf, size))
96 vdso = vdso_file->temp_file_name;
103 vdso_file->found = (vdso != NULL);
104 vdso_file->error = !vdso_file->found;
108 void machine__exit_vdso(struct machine *machine)
110 struct vdso_info *vdso_info = machine->vdso_info;
115 if (vdso_info->vdso.found)
116 unlink(vdso_info->vdso.temp_file_name);
117 #if BITS_PER_LONG == 64
118 if (vdso_info->vdso32.found)
119 unlink(vdso_info->vdso32.temp_file_name);
120 if (vdso_info->vdsox32.found)
121 unlink(vdso_info->vdsox32.temp_file_name);
124 zfree(&machine->vdso_info);
127 static struct dso *__machine__addnew_vdso(struct machine *machine, const char *short_name,
128 const char *long_name)
132 dso = dso__new(short_name);
134 __dsos__add(&machine->dsos, dso);
135 dso__set_long_name(dso, long_name, false);
136 /* Put dso here because __dsos_add already got it */
143 static enum dso_type machine__thread_dso_type(struct machine *machine,
144 struct thread *thread)
146 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
149 maps__for_each_entry(thread->maps, map) {
150 struct dso *dso = map->dso;
151 if (!dso || dso->long_name[0] != '/')
153 dso_type = dso__type(dso, machine);
154 if (dso_type != DSO__TYPE_UNKNOWN)
161 #if BITS_PER_LONG == 64
163 static int vdso__do_copy_compat(FILE *f, int fd)
169 count = fread(buf, 1, sizeof(buf), f);
174 if (count && writen(fd, buf, count) != (ssize_t)count)
181 static int vdso__copy_compat(const char *prog, int fd)
186 f = popen(prog, "r");
190 err = vdso__do_copy_compat(f, fd);
198 static int vdso__create_compat_file(const char *prog, char *temp_name)
202 fd = mkstemp(temp_name);
206 err = vdso__copy_compat(prog, fd);
214 static const char *vdso__get_compat_file(struct vdso_file *vdso_file)
218 if (vdso_file->found)
219 return vdso_file->temp_file_name;
221 if (vdso_file->error)
224 err = vdso__create_compat_file(vdso_file->read_prog,
225 vdso_file->temp_file_name);
227 pr_err("%s failed, error %d\n", vdso_file->read_prog, err);
228 vdso_file->error = true;
232 vdso_file->found = true;
234 return vdso_file->temp_file_name;
237 static struct dso *__machine__findnew_compat(struct machine *machine,
238 struct vdso_file *vdso_file)
240 const char *file_name;
243 dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
247 file_name = vdso__get_compat_file(vdso_file);
251 dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
256 static int __machine__findnew_vdso_compat(struct machine *machine,
257 struct thread *thread,
258 struct vdso_info *vdso_info,
261 enum dso_type dso_type;
263 dso_type = machine__thread_dso_type(machine, thread);
265 #ifndef HAVE_PERF_READ_VDSO32
266 if (dso_type == DSO__TYPE_32BIT)
269 #ifndef HAVE_PERF_READ_VDSOX32
270 if (dso_type == DSO__TYPE_X32BIT)
275 case DSO__TYPE_32BIT:
276 *dso = __machine__findnew_compat(machine, &vdso_info->vdso32);
278 case DSO__TYPE_X32BIT:
279 *dso = __machine__findnew_compat(machine, &vdso_info->vdsox32);
281 case DSO__TYPE_UNKNOWN:
282 case DSO__TYPE_64BIT:
290 static struct dso *machine__find_vdso(struct machine *machine,
291 struct thread *thread)
293 struct dso *dso = NULL;
294 enum dso_type dso_type;
296 dso_type = machine__thread_dso_type(machine, thread);
298 case DSO__TYPE_32BIT:
299 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO32, true);
301 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO,
303 if (dso && dso_type != dso__type(dso, machine))
307 case DSO__TYPE_X32BIT:
308 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true);
310 case DSO__TYPE_64BIT:
311 case DSO__TYPE_UNKNOWN:
313 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
320 struct dso *machine__findnew_vdso(struct machine *machine,
321 struct thread *thread)
323 struct vdso_info *vdso_info;
324 struct dso *dso = NULL;
326 down_write(&machine->dsos.lock);
327 if (!machine->vdso_info)
328 machine->vdso_info = vdso_info__new();
330 vdso_info = machine->vdso_info;
334 dso = machine__find_vdso(machine, thread);
338 #if BITS_PER_LONG == 64
339 if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
343 dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
347 file = get_file(&vdso_info->vdso);
349 dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
354 up_write(&machine->dsos.lock);
358 bool dso__is_vdso(struct dso *dso)
360 return !strcmp(dso->short_name, DSO__NAME_VDSO) ||
361 !strcmp(dso->short_name, DSO__NAME_VDSO32) ||
362 !strcmp(dso->short_name, DSO__NAME_VDSOX32);