[mirror_ubuntu-jammy-kernel.git] / tools / perf / util / vdso.c

// 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);
	}

	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);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
a43783ae	2	#include <errno.h>
7dbf4dcf JO	3	#include <unistd.h>
	4	#include <stdio.h>
	5	#include <string.h>
	6	#include <sys/types.h>
	7	#include <sys/stat.h>
	8	#include <fcntl.h>
	9	#include <stdlib.h>
	10	#include <linux/kernel.h>
	11
	12	#include "vdso.h"
4a3cec84	13	#include "dso.h"
fb71c86c	14	#include <internal/lib.h>
1101f69a	15	#include "map.h"
7dbf4dcf	16	#include "symbol.h"
2a03068c	17	#include "machine.h"
f6832e17	18	#include "thread.h"
7dbf4dcf	19	#include "linux/string.h"
7f7c536f	20	#include <linux/zalloc.h>
84f5d36f	21	#include "debug.h"
7dbf4dcf	22
e477f3f0	23	/*
01153237	24	* Include definition of find_map() also used in perf-read-vdso.c for
e477f3f0 AH	25	* building perf-read-vdso32 and perf-read-vdsox32.
e477f3f0 AH	26	*/
01153237	27	#include "find-map.c"
e477f3f0	28
30f4f815 AH	29	#define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX"
	30
	31	struct vdso_file {
	32	bool found;
	33	bool error;
	34	char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
	35	const char *dso_name;
f6832e17	36	const char *read_prog;
30f4f815 AH	37	};
	38
	39	struct vdso_info {
	40	struct vdso_file vdso;
f6832e17 AH	41	#if BITS_PER_LONG == 64
	42	struct vdso_file vdso32;
	43	struct vdso_file vdsox32;
	44	#endif
30f4f815 AH	45	};
30f4f815 AH	46
d027b640 AH	47	static struct vdso_info *vdso_info__new(void)
	48	{
	49	static const struct vdso_info vdso_info_init = {
	50	.vdso = {
	51	.temp_file_name = VDSO__TEMP_FILE_NAME,
51682dc7	52	.dso_name = DSO__NAME_VDSO,
d027b640	53	},
f6832e17 AH	54	#if BITS_PER_LONG == 64
	55	.vdso32 = {
	56	.temp_file_name = VDSO__TEMP_FILE_NAME,
	57	.dso_name = DSO__NAME_VDSO32,
	58	.read_prog = "perf-read-vdso32",
	59	},
	60	.vdsox32 = {
	61	.temp_file_name = VDSO__TEMP_FILE_NAME,
	62	.dso_name = DSO__NAME_VDSOX32,
	63	.read_prog = "perf-read-vdsox32",
	64	},
	65	#endif
d027b640 AH	66	};
	67
	68	return memdup(&vdso_info_init, sizeof(vdso_info_init));
	69	}
7dbf4dcf	70
30f4f815	71	static char get_file(struct vdso_file vdso_file)
7dbf4dcf JO	72	{
	73	char *vdso = NULL;
	74	char *buf = NULL;
	75	void start, end;
	76	size_t size;
	77	int fd;
	78
30f4f815 AH	79	if (vdso_file->found)
30f4f815 AH	80	return vdso_file->temp_file_name;
7dbf4dcf	81
01153237	82	if (vdso_file->error \|\| find_map(&start, &end, VDSO__MAP_NAME))
7dbf4dcf JO	83	return NULL;
	84
	85	size = end - start;
	86
	87	buf = memdup(start, size);
	88	if (!buf)
	89	return NULL;
	90
30f4f815	91	fd = mkstemp(vdso_file->temp_file_name);
7dbf4dcf JO	92	if (fd < 0)
	93	goto out;
	94
	95	if (size == (size_t) write(fd, buf, size))
30f4f815	96	vdso = vdso_file->temp_file_name;
7dbf4dcf JO	97
	98	close(fd);
	99
	100	out:
	101	free(buf);
	102
30f4f815 AH	103	vdso_file->found = (vdso != NULL);
30f4f815 AH	104	vdso_file->error = !vdso_file->found;
7dbf4dcf JO	105	return vdso;
	106	}
	107
9a4388c7	108	void machine__exit_vdso(struct machine *machine)
7dbf4dcf	109	{
d027b640 AH	110	struct vdso_info *vdso_info = machine->vdso_info;
	111
	112	if (!vdso_info)
	113	return;
	114
30f4f815 AH	115	if (vdso_info->vdso.found)
30f4f815 AH	116	unlink(vdso_info->vdso.temp_file_name);
f6832e17 AH	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);
	122	#endif
d027b640 AH	123
d027b640 AH	124	zfree(&machine->vdso_info);
7dbf4dcf JO	125	}
7dbf4dcf JO	126
e8807844 ACM	127	static struct dso __machine__addnew_vdso(struct machine machine, const char *short_name,
e8807844 ACM	128	const char *long_name)
4f71f2a0 AH	129	{
	130	struct dso *dso;
	131
	132	dso = dso__new(short_name);
	133	if (dso != NULL) {
e8807844	134	__dsos__add(&machine->dsos, dso);
4f71f2a0 AH	135	dso__set_long_name(dso, long_name, false);
	136	}
	137
	138	return dso;
	139	}
	140
f6832e17 AH	141	static enum dso_type machine__thread_dso_type(struct machine *machine,
	142	struct thread *thread)
	143	{
	144	enum dso_type dso_type = DSO__TYPE_UNKNOWN;
50481461	145	struct map *map;
f6832e17	146
fe87797d	147	maps__for_each_entry(thread->maps, map) {
dce0478b	148	struct dso *dso = map->dso;
f6832e17 AH	149	if (!dso \|\| dso->long_name[0] != '/')
	150	continue;
	151	dso_type = dso__type(dso, machine);
	152	if (dso_type != DSO__TYPE_UNKNOWN)
	153	break;
	154	}
	155
	156	return dso_type;
	157	}
	158
76c588f1 HK	159	#if BITS_PER_LONG == 64
76c588f1 HK	160
f6832e17 AH	161	static int vdso__do_copy_compat(FILE *f, int fd)
	162	{
	163	char buf[4096];
	164	size_t count;
	165
	166	while (1) {
	167	count = fread(buf, 1, sizeof(buf), f);
	168	if (ferror(f))
	169	return -errno;
	170	if (feof(f))
	171	break;
	172	if (count && writen(fd, buf, count) != (ssize_t)count)
	173	return -errno;
	174	}
	175
	176	return 0;
	177	}
	178
	179	static int vdso__copy_compat(const char *prog, int fd)
	180	{
	181	FILE *f;
	182	int err;
	183
	184	f = popen(prog, "r");
	185	if (!f)
	186	return -errno;
	187
	188	err = vdso__do_copy_compat(f, fd);
	189
	190	if (pclose(f) == -1)
	191	return -errno;
	192
	193	return err;
	194	}
	195
	196	static int vdso__create_compat_file(const char prog, char temp_name)
	197	{
	198	int fd, err;
	199
	200	fd = mkstemp(temp_name);
	201	if (fd < 0)
	202	return -errno;
	203
	204	err = vdso__copy_compat(prog, fd);
	205
	206	if (close(fd) == -1)
	207	return -errno;
	208
	209	return err;
	210	}
	211
	212	static const char vdso__get_compat_file(struct vdso_file vdso_file)
	213	{
	214	int err;
	215
	216	if (vdso_file->found)
	217	return vdso_file->temp_file_name;
	218
	219	if (vdso_file->error)
	220	return NULL;
	221
	222	err = vdso__create_compat_file(vdso_file->read_prog,
	223	vdso_file->temp_file_name);
	224	if (err) {
225	pr_err("%s failed, error %d\n", vdso_file->read_prog, err);
226	vdso_file->error = true;
227	return NULL;
228	}
229
230	vdso_file->found = true;
231
232	return vdso_file->temp_file_name;
233	}
234
e8807844 ACM	235	static struct dso __machine__findnew_compat(struct machine machine,
e8807844 ACM	236	struct vdso_file *vdso_file)
f6832e17 AH	237	{
	238	const char *file_name;
	239	struct dso *dso;
	240
e8807844	241	dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
f6832e17	242	if (dso)
6d545a63	243	goto out;
f6832e17 AH	244
	245	file_name = vdso__get_compat_file(vdso_file);
	246	if (!file_name)
6d545a63	247	goto out;
f6832e17	248
e8807844	249	dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
6d545a63	250	out:
e8807844	251	return dso;
f6832e17 AH	252	}
f6832e17 AH	253
e8807844 ACM	254	static int __machine__findnew_vdso_compat(struct machine *machine,
	255	struct thread *thread,
	256	struct vdso_info *vdso_info,
	257	struct dso **dso)
f6832e17 AH	258	{
	259	enum dso_type dso_type;
	260
	261	dso_type = machine__thread_dso_type(machine, thread);
46b1fa85 AH	262
	263	#ifndef HAVE_PERF_READ_VDSO32
	264	if (dso_type == DSO__TYPE_32BIT)
	265	return 0;
	266	#endif
	267	#ifndef HAVE_PERF_READ_VDSOX32
	268	if (dso_type == DSO__TYPE_X32BIT)
	269	return 0;
	270	#endif
	271
f6832e17 AH	272	switch (dso_type) {
f6832e17 AH	273	case DSO__TYPE_32BIT:
e8807844	274	*dso = __machine__findnew_compat(machine, &vdso_info->vdso32);
f6832e17 AH	275	return 1;
f6832e17 AH	276	case DSO__TYPE_X32BIT:
e8807844	277	*dso = __machine__findnew_compat(machine, &vdso_info->vdsox32);
f6832e17 AH	278	return 1;
	279	case DSO__TYPE_UNKNOWN:
	280	case DSO__TYPE_64BIT:
	281	default:
	282	return 0;
	283	}
	284	}
	285
	286	#endif
	287
76c588f1 HK	288	static struct dso machine__find_vdso(struct machine machine,
	289	struct thread *thread)
	290	{
	291	struct dso *dso = NULL;
	292	enum dso_type dso_type;
	293
	294	dso_type = machine__thread_dso_type(machine, thread);
	295	switch (dso_type) {
	296	case DSO__TYPE_32BIT:
	297	dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO32, true);
	298	if (!dso) {
	299	dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO,
	300	true);
	301	if (dso && dso_type != dso__type(dso, machine))
	302	dso = NULL;
	303	}
	304	break;
	305	case DSO__TYPE_X32BIT:
	306	dso = __dsos__find(&machine->dsos, DSO__NAME_VDSOX32, true);
	307	break;
	308	case DSO__TYPE_64BIT:
	309	case DSO__TYPE_UNKNOWN:
	310	default:
	311	dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
	312	break;
	313	}
	314
	315	return dso;
	316	}
	317
9a4388c7	318	struct dso machine__findnew_vdso(struct machine machine,
76c588f1	319	struct thread *thread)
7dbf4dcf	320	{
d027b640	321	struct vdso_info *vdso_info;
e8807844	322	struct dso *dso = NULL;
d027b640	323
0a7c74ea	324	down_write(&machine->dsos.lock);
d027b640 AH	325	if (!machine->vdso_info)
	326	machine->vdso_info = vdso_info__new();
	327
	328	vdso_info = machine->vdso_info;
	329	if (!vdso_info)
e8807844	330	goto out_unlock;
7dbf4dcf	331
76c588f1 HK	332	dso = machine__find_vdso(machine, thread);
	333	if (dso)
	334	goto out_unlock;
	335
f6832e17	336	#if BITS_PER_LONG == 64
e8807844 ACM	337	if (__machine__findnew_vdso_compat(machine, thread, vdso_info, &dso))
e8807844 ACM	338	goto out_unlock;
f6832e17 AH	339	#endif
f6832e17 AH	340
e8807844	341	dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true);
7dbf4dcf JO	342	if (!dso) {
	343	char *file;
	344
30f4f815	345	file = get_file(&vdso_info->vdso);
e8807844 ACM	346	if (file)
e8807844 ACM	347	dso = __machine__addnew_vdso(machine, DSO__NAME_VDSO, file);
7dbf4dcf JO	348	}
7dbf4dcf JO	349
e8807844	350	out_unlock:
d3a7c489	351	dso__get(dso);
0a7c74ea	352	up_write(&machine->dsos.lock);
7dbf4dcf JO	353	return dso;
7dbf4dcf JO	354	}
51682dc7 AH	355
	356	bool dso__is_vdso(struct dso *dso)
	357	{
f6832e17 AH	358	return !strcmp(dso->short_name, DSO__NAME_VDSO) \|\|
	359	!strcmp(dso->short_name, DSO__NAME_VDSO32) \|\|
	360	!strcmp(dso->short_name, DSO__NAME_VDSOX32);
51682dc7	361	}