[thirdparty/kernel/linux.git] / tools / perf / util / bpf-event.c

// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <stdlib.h>
#include <bpf/bpf.h>
#include <bpf/btf.h>
#include <bpf/libbpf.h>
#include <linux/btf.h>
#include <linux/err.h>
#include "bpf-event.h"
#include "debug.h"
#include "symbol.h"
#include "machine.h"
#include "env.h"
#include "session.h"

#define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))

static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
{
	int ret = 0;
	size_t i;

	for (i = 0; i < len; i++)
		ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
	return ret;
}

int machine__process_bpf_event(struct machine *machine __maybe_unused,
			       union perf_event *event,
			       struct perf_sample *sample __maybe_unused)
{
	if (dump_trace)
		perf_event__fprintf_bpf_event(event, stdout);
	return 0;
}

/*
 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
 * one PERF_RECORD_KSYMBOL is generated for each sub program.
 *
 * Returns:
 *    0 for success;
 *   -1 for failures;
 *   -2 for lack of kernel support.
 */
static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
					       perf_event__handler_t process,
					       struct machine *machine,
					       int fd,
					       union perf_event *event,
					       struct record_opts *opts)
{
	struct ksymbol_event *ksymbol_event = &event->ksymbol_event;
	struct bpf_event *bpf_event = &event->bpf_event;
	struct bpf_prog_info_linear *info_linear;
	struct perf_tool *tool = session->tool;
	struct bpf_prog_info_node *info_node;
	struct bpf_prog_info *info;
	struct btf *btf = NULL;
	bool has_btf = false;
	struct perf_env *env;
	u32 sub_prog_cnt, i;
	int err = 0;
	u64 arrays;

	/*
	 * for perf-record and perf-report use header.env;
	 * otherwise, use global perf_env.
	 */
	env = session->data ? &session->header.env : &perf_env;

	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
	arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
	arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;

	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
	if (IS_ERR_OR_NULL(info_linear)) {
		info_linear = NULL;
		pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
		return -1;
	}

	if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
		pr_debug("%s: the kernel is too old, aborting\n", __func__);
		return -2;
	}

	info = &info_linear->info;

	/* number of ksyms, func_lengths, and tags should match */
	sub_prog_cnt = info->nr_jited_ksyms;
	if (sub_prog_cnt != info->nr_prog_tags ||
	    sub_prog_cnt != info->nr_jited_func_lens)
		return -1;

	/* check BTF func info support */
	if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
		/* btf func info number should be same as sub_prog_cnt */
		if (sub_prog_cnt != info->nr_func_info) {
			pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
			err = -1;
			goto out;
		}
		if (btf__get_from_id(info->btf_id, &btf)) {
			pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
			err = -1;
			btf = NULL;
			goto out;
		}
		has_btf = true;
	}

	/* Synthesize PERF_RECORD_KSYMBOL */
	for (i = 0; i < sub_prog_cnt; i++) {
		u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
		__u32 *prog_lens  = (__u32 *)(uintptr_t)(info->jited_func_lens);
		__u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
		void *func_infos  = (void *)(uintptr_t)(info->func_info);
		const struct bpf_func_info *finfo;
		const char *short_name = NULL;
		const struct btf_type *t;
		int name_len;

		*ksymbol_event = (struct ksymbol_event){
			.header = {
				.type = PERF_RECORD_KSYMBOL,
				.size = offsetof(struct ksymbol_event, name),
			},
			.addr = prog_addrs[i],
			.len = prog_lens[i],
			.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
			.flags = 0,
		};
		name_len = snprintf(ksymbol_event->name, KSYM_NAME_LEN,
				    "bpf_prog_");
		name_len += snprintf_hex(ksymbol_event->name + name_len,
					 KSYM_NAME_LEN - name_len,
					 prog_tags[i], BPF_TAG_SIZE);
		if (has_btf) {
			finfo = func_infos + i * info->func_info_rec_size;
			t = btf__type_by_id(btf, finfo->type_id);
			short_name = btf__name_by_offset(btf, t->name_off);
		} else if (i == 0 && sub_prog_cnt == 1) {
			/* no subprog */
			if (info->name[0])
				short_name = info->name;
		} else
			short_name = "F";
		if (short_name)
			name_len += snprintf(ksymbol_event->name + name_len,
					     KSYM_NAME_LEN - name_len,
					     "_%s", short_name);

		ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
							 sizeof(u64));

		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
		event->header.size += machine->id_hdr_size;
		err = perf_tool__process_synth_event(tool, event,
						     machine, process);
	}

	if (!opts->no_bpf_event) {
		/* Synthesize PERF_RECORD_BPF_EVENT */
		*bpf_event = (struct bpf_event){
			.header = {
				.type = PERF_RECORD_BPF_EVENT,
				.size = sizeof(struct bpf_event),
			},
			.type = PERF_BPF_EVENT_PROG_LOAD,
			.flags = 0,
			.id = info->id,
		};
		memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
		event->header.size += machine->id_hdr_size;

		/* save bpf_prog_info to env */
		info_node = malloc(sizeof(struct bpf_prog_info_node));
		if (!info_node) {
			err = -1;
			goto out;
		}

		info_node->info_linear = info_linear;
		perf_env__insert_bpf_prog_info(env, info_node);
		info_linear = NULL;

		/*
		 * process after saving bpf_prog_info to env, so that
		 * required information is ready for look up
		 */
		err = perf_tool__process_synth_event(tool, event,
						     machine, process);
	}

out:
	free(info_linear);
	free(btf);
	return err ? -1 : 0;
}

int perf_event__synthesize_bpf_events(struct perf_session *session,
				      perf_event__handler_t process,
				      struct machine *machine,
				      struct record_opts *opts)
{
	union perf_event *event;
	__u32 id = 0;
	int err;
	int fd;

	event = malloc(sizeof(event->bpf_event) + KSYM_NAME_LEN + machine->id_hdr_size);
	if (!event)
		return -1;
	while (true) {
		err = bpf_prog_get_next_id(id, &id);
		if (err) {
			if (errno == ENOENT) {
				err = 0;
				break;
			}
			pr_debug("%s: can't get next program: %s%s\n",
				 __func__, strerror(errno),
				 errno == EINVAL ? " -- kernel too old?" : "");
			/* don't report error on old kernel or EPERM  */
			err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
			break;
		}
		fd = bpf_prog_get_fd_by_id(id);
		if (fd < 0) {
			pr_debug("%s: failed to get fd for prog_id %u\n",
				 __func__, id);
			continue;
		}

		err = perf_event__synthesize_one_bpf_prog(session, process,
							  machine, fd,
							  event, opts);
		close(fd);
		if (err) {
			/* do not return error for old kernel */
			if (err == -2)
				err = 0;
			break;
		}
	}
	free(event);
	return err;
}
Commit	Line	Data
45178a92 SL	1	// SPDX-License-Identifier: GPL-2.0
45178a92 SL	2	#include <errno.h>
7b612e29	3	#include <stdlib.h>
45178a92	4	#include <bpf/bpf.h>
7b612e29	5	#include <bpf/btf.h>
a742258a	6	#include <bpf/libbpf.h>
7b612e29	7	#include <linux/btf.h>
a742258a	8	#include <linux/err.h>
45178a92 SL	9	#include "bpf-event.h"
	10	#include "debug.h"
	11	#include "symbol.h"
811184fb	12	#include "machine.h"
e4378f0c	13	#include "env.h"
e5416950	14	#include "session.h"
45178a92	15
7b612e29 SL	16	#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))
	17
	18	static int snprintf_hex(char buf, size_t size, unsigned char data, size_t len)
	19	{
	20	int ret = 0;
	21	size_t i;
	22
	23	for (i = 0; i < len; i++)
	24	ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
	25	return ret;
	26	}
	27
45178a92 SL	28	int machine__process_bpf_event(struct machine *machine __maybe_unused,
	29	union perf_event *event,
	30	struct perf_sample *sample __maybe_unused)
	31	{
	32	if (dump_trace)
	33	perf_event__fprintf_bpf_event(event, stdout);
	34	return 0;
	35	}
7b612e29 SL	36
	37	/*
	38	* Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
	39	* program. One PERF_RECORD_BPF_EVENT is generated for the program. And
	40	* one PERF_RECORD_KSYMBOL is generated for each sub program.
	41	*
	42	* Returns:
	43	* 0 for success;
	44	* -1 for failures;
	45	* -2 for lack of kernel support.
	46	*/
e5416950	47	static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
7b612e29 SL	48	perf_event__handler_t process,
	49	struct machine *machine,
	50	int fd,
	51	union perf_event *event,
	52	struct record_opts *opts)
	53	{
	54	struct ksymbol_event *ksymbol_event = &event->ksymbol_event;
	55	struct bpf_event *bpf_event = &event->bpf_event;
a742258a	56	struct bpf_prog_info_linear *info_linear;
e5416950	57	struct perf_tool *tool = session->tool;
e4378f0c	58	struct bpf_prog_info_node *info_node;
a742258a	59	struct bpf_prog_info *info;
7b612e29	60	struct btf *btf = NULL;
7b612e29	61	bool has_btf = false;
e4378f0c	62	struct perf_env *env;
a742258a	63	u32 sub_prog_cnt, i;
7b612e29	64	int err = 0;
a742258a	65	u64 arrays;
7b612e29	66
e4378f0c SL	67	/*
	68	* for perf-record and perf-report use header.env;
	69	* otherwise, use global perf_env.
	70	*/
	71	env = session->data ? &session->header.env : &perf_env;
	72
a742258a SL	73	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
	74	arrays \|= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
	75	arrays \|= 1UL << BPF_PROG_INFO_FUNC_INFO;
	76	arrays \|= 1UL << BPF_PROG_INFO_PROG_TAGS;
e4378f0c SL	77	arrays \|= 1UL << BPF_PROG_INFO_JITED_INSNS;
	78	arrays \|= 1UL << BPF_PROG_INFO_LINE_INFO;
	79	arrays \|= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
7b612e29	80
a742258a SL	81	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
	82	if (IS_ERR_OR_NULL(info_linear)) {
	83	info_linear = NULL;
	84	pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
7b612e29 SL	85	return -1;
7b612e29 SL	86	}
a742258a SL	87
a742258a SL	88	if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
7b612e29 SL	89	pr_debug("%s: the kernel is too old, aborting\n", __func__);
	90	return -2;
	91	}
	92
a742258a SL	93	info = &info_linear->info;
a742258a SL	94
7b612e29	95	/* number of ksyms, func_lengths, and tags should match */
a742258a SL	96	sub_prog_cnt = info->nr_jited_ksyms;
	97	if (sub_prog_cnt != info->nr_prog_tags \|\|
	98	sub_prog_cnt != info->nr_jited_func_lens)
7b612e29 SL	99	return -1;
	100
	101	/* check BTF func info support */
a742258a	102	if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
7b612e29	103	/* btf func info number should be same as sub_prog_cnt */
a742258a	104	if (sub_prog_cnt != info->nr_func_info) {
7b612e29	105	pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
a742258a SL	106	err = -1;
a742258a SL	107	goto out;
7b612e29	108	}
a742258a SL	109	if (btf__get_from_id(info->btf_id, &btf)) {
	110	pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
	111	err = -1;
	112	btf = NULL;
	113	goto out;
7b612e29 SL	114	}
	115	has_btf = true;
	116	}
	117
7b612e29 SL	118	/* Synthesize PERF_RECORD_KSYMBOL */
7b612e29 SL	119	for (i = 0; i < sub_prog_cnt; i++) {
a742258a SL	120	u8 (prog_tags)[BPF_TAG_SIZE] = (void )(uintptr_t)(info->prog_tags);
	121	__u32 prog_lens = (__u32 )(uintptr_t)(info->jited_func_lens);
	122	__u64 prog_addrs = (__u64 )(uintptr_t)(info->jited_ksyms);
	123	void func_infos = (void )(uintptr_t)(info->func_info);
7b612e29 SL	124	const struct bpf_func_info *finfo;
	125	const char *short_name = NULL;
	126	const struct btf_type *t;
	127	int name_len;
	128
	129	*ksymbol_event = (struct ksymbol_event){
	130	.header = {
	131	.type = PERF_RECORD_KSYMBOL,
811184fb	132	.size = offsetof(struct ksymbol_event, name),
7b612e29 SL	133	},
	134	.addr = prog_addrs[i],
	135	.len = prog_lens[i],
	136	.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
	137	.flags = 0,
	138	};
	139	name_len = snprintf(ksymbol_event->name, KSYM_NAME_LEN,
	140	"bpf_prog_");
	141	name_len += snprintf_hex(ksymbol_event->name + name_len,
	142	KSYM_NAME_LEN - name_len,
	143	prog_tags[i], BPF_TAG_SIZE);
	144	if (has_btf) {
a742258a	145	finfo = func_infos + i * info->func_info_rec_size;
7b612e29 SL	146	t = btf__type_by_id(btf, finfo->type_id);
	147	short_name = btf__name_by_offset(btf, t->name_off);
	148	} else if (i == 0 && sub_prog_cnt == 1) {
	149	/* no subprog */
a742258a SL	150	if (info->name[0])
a742258a SL	151	short_name = info->name;
7b612e29 SL	152	} else
	153	short_name = "F";
	154	if (short_name)
	155	name_len += snprintf(ksymbol_event->name + name_len,
	156	KSYM_NAME_LEN - name_len,
	157	"_%s", short_name);
	158
	159	ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
	160	sizeof(u64));
811184fb SL	161
	162	memset((void *)event + event->header.size, 0, machine->id_hdr_size);
	163	event->header.size += machine->id_hdr_size;
7b612e29 SL	164	err = perf_tool__process_synth_event(tool, event,
	165	machine, process);
	166	}
	167
71184c6a	168	if (!opts->no_bpf_event) {
e4378f0c	169	/* Synthesize PERF_RECORD_BPF_EVENT */
7b612e29 SL	170	*bpf_event = (struct bpf_event){
	171	.header = {
	172	.type = PERF_RECORD_BPF_EVENT,
	173	.size = sizeof(struct bpf_event),
	174	},
	175	.type = PERF_BPF_EVENT_PROG_LOAD,
	176	.flags = 0,
a742258a	177	.id = info->id,
7b612e29	178	};
a742258a	179	memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
811184fb SL	180	memset((void *)event + event->header.size, 0, machine->id_hdr_size);
811184fb SL	181	event->header.size += machine->id_hdr_size;
e4378f0c SL	182
	183	/* save bpf_prog_info to env */
	184	info_node = malloc(sizeof(struct bpf_prog_info_node));
	185	if (!info_node) {
	186	err = -1;
	187	goto out;
	188	}
	189
	190	info_node->info_linear = info_linear;
	191	perf_env__insert_bpf_prog_info(env, info_node);
	192	info_linear = NULL;
	193
	194	/*
	195	* process after saving bpf_prog_info to env, so that
	196	* required information is ready for look up
	197	*/
7b612e29 SL	198	err = perf_tool__process_synth_event(tool, event,
	199	machine, process);
	200	}
	201
	202	out:
a742258a	203	free(info_linear);
7b612e29 SL	204	free(btf);
	205	return err ? -1 : 0;
	206	}
	207
e5416950	208	int perf_event__synthesize_bpf_events(struct perf_session *session,
7b612e29 SL	209	perf_event__handler_t process,
	210	struct machine *machine,
	211	struct record_opts *opts)
	212	{
	213	union perf_event *event;
	214	__u32 id = 0;
	215	int err;
	216	int fd;
	217
811184fb	218	event = malloc(sizeof(event->bpf_event) + KSYM_NAME_LEN + machine->id_hdr_size);
7b612e29 SL	219	if (!event)
	220	return -1;
	221	while (true) {
	222	err = bpf_prog_get_next_id(id, &id);
	223	if (err) {
	224	if (errno == ENOENT) {
	225	err = 0;
	226	break;
	227	}
b20fe106	228	pr_debug("%s: can't get next program: %s%s\n",
7b612e29 SL	229	__func__, strerror(errno),
7b612e29 SL	230	errno == EINVAL ? " -- kernel too old?" : "");
39f4a913 SL	231	/* don't report error on old kernel or EPERM */
39f4a913 SL	232	err = (errno == EINVAL \|\| errno == EPERM) ? 0 : -1;
7b612e29 SL	233	break;
	234	}
	235	fd = bpf_prog_get_fd_by_id(id);
	236	if (fd < 0) {
	237	pr_debug("%s: failed to get fd for prog_id %u\n",
	238	__func__, id);
	239	continue;
	240	}
	241
e5416950	242	err = perf_event__synthesize_one_bpf_prog(session, process,
7b612e29 SL	243	machine, fd,
	244	event, opts);
	245	close(fd);
	246	if (err) {
	247	/* do not return error for old kernel */
	248	if (err == -2)
	249	err = 0;
	250	break;
	251	}
	252	}
	253	free(event);
	254	return err;
	255	}