[linux-block.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 <linux/string.h>
#include <internal/lib.h>
#include <symbol/kallsyms.h>
#include "bpf-event.h"
#include "bpf-utils.h"
#include "debug.h"
#include "dso.h"
#include "symbol.h"
#include "machine.h"
#include "env.h"
#include "session.h"
#include "map.h"
#include "evlist.h"
#include "record.h"
#include "util/synthetic-events.h"

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;
}

static int machine__process_bpf_event_load(struct machine *machine,
					   union perf_event *event,
					   struct perf_sample *sample __maybe_unused)
{
	struct bpf_prog_info_node *info_node;
	struct perf_env *env = machine->env;
	struct perf_bpil *info_linear;
	int id = event->bpf.id;
	unsigned int i;

	/* perf-record, no need to handle bpf-event */
	if (env == NULL)
		return 0;

	info_node = perf_env__find_bpf_prog_info(env, id);
	if (!info_node)
		return 0;
	info_linear = info_node->info_linear;

	for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
		u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);
		u64 addr = addrs[i];
		struct map *map = maps__find(machine__kernel_maps(machine), addr);

		if (map) {
			struct dso *dso = map__dso(map);

			dso__set_binary_type(dso, DSO_BINARY_TYPE__BPF_PROG_INFO);
			dso__bpf_prog(dso)->id = id;
			dso__bpf_prog(dso)->sub_id = i;
			dso__bpf_prog(dso)->env = env;
			map__put(map);
		}
	}
	return 0;
}

int machine__process_bpf(struct machine *machine, union perf_event *event,
			 struct perf_sample *sample)
{
	if (dump_trace)
		perf_event__fprintf_bpf(event, stdout);

	switch (event->bpf.type) {
	case PERF_BPF_EVENT_PROG_LOAD:
		return machine__process_bpf_event_load(machine, event, sample);

	case PERF_BPF_EVENT_PROG_UNLOAD:
		/*
		 * Do not free bpf_prog_info and btf of the program here,
		 * as annotation still need them. They will be freed at
		 * the end of the session.
		 */
		break;
	default:
		pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
		break;
	}
	return 0;
}

static int perf_env__fetch_btf(struct perf_env *env,
			       u32 btf_id,
			       struct btf *btf)
{
	struct btf_node *node;
	u32 data_size;
	const void *data;

	data = btf__raw_data(btf, &data_size);

	node = malloc(data_size + sizeof(struct btf_node));
	if (!node)
		return -1;

	node->id = btf_id;
	node->data_size = data_size;
	memcpy(node->data, data, data_size);

	if (!perf_env__insert_btf(env, node)) {
		/* Insertion failed because of a duplicate. */
		free(node);
		return -1;
	}
	return 0;
}

static int synthesize_bpf_prog_name(char *buf, int size,
				    struct bpf_prog_info *info,
				    struct btf *btf,
				    u32 sub_id)
{
	u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
	void *func_infos = (void *)(uintptr_t)(info->func_info);
	u32 sub_prog_cnt = info->nr_jited_ksyms;
	const struct bpf_func_info *finfo;
	const char *short_name = NULL;
	const struct btf_type *t;
	int name_len;

	name_len = snprintf(buf, size, "bpf_prog_");
	name_len += snprintf_hex(buf + name_len, size - name_len,
				 prog_tags[sub_id], BPF_TAG_SIZE);
	if (btf) {
		finfo = func_infos + sub_id * 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 (sub_id == 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(buf + name_len, size - name_len,
				     "_%s", short_name);
	return name_len;
}

/*
 * 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 perf_record_ksymbol *ksymbol_event = &event->ksymbol;
	struct perf_record_bpf_event *bpf_event = &event->bpf;
	struct perf_tool *tool = session->tool;
	struct bpf_prog_info_node *info_node;
	struct perf_bpil *info_linear;
	struct bpf_prog_info *info;
	struct btf *btf = NULL;
	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 << PERF_BPIL_JITED_KSYMS;
	arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
	arrays |= 1UL << PERF_BPIL_FUNC_INFO;
	arrays |= 1UL << PERF_BPIL_PROG_TAGS;
	arrays |= 1UL << PERF_BPIL_JITED_INSNS;
	arrays |= 1UL << PERF_BPIL_LINE_INFO;
	arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;

	info_linear = get_bpf_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)) {
		free(info_linear);
		pr_debug("%s: the kernel is too old, aborting\n", __func__);
		return -2;
	}

	info = &info_linear->info;
	if (!info->jited_ksyms) {
		free(info_linear);
		return -1;
	}

	/* 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) {
		free(info_linear);
		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__);
			free(info_linear);
			return -1;
		}
		btf = btf__load_from_kernel_by_id(info->btf_id);
		if (libbpf_get_error(btf)) {
			pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
			err = -1;
			goto out;
		}
		perf_env__fetch_btf(env, info->btf_id, btf);
	}

	/* Synthesize PERF_RECORD_KSYMBOL */
	for (i = 0; i < sub_prog_cnt; i++) {
		__u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
		__u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
		int name_len;

		*ksymbol_event = (struct perf_record_ksymbol) {
			.header = {
				.type = PERF_RECORD_KSYMBOL,
				.size = offsetof(struct perf_record_ksymbol, name),
			},
			.addr = prog_addrs[i],
			.len = prog_lens[i],
			.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
			.flags = 0,
		};

		name_len = synthesize_bpf_prog_name(ksymbol_event->name,
						    KSYM_NAME_LEN, info, btf, i);
		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 perf_record_bpf_event) {
			.header = {
				.type = PERF_RECORD_BPF_EVENT,
				.size = sizeof(struct perf_record_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);
	btf__free(btf);
	return err ? -1 : 0;
}

struct kallsyms_parse {
	union perf_event	*event;
	perf_event__handler_t	 process;
	struct machine		*machine;
	struct perf_tool	*tool;
};

static int
process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data)
{
	struct machine *machine = data->machine;
	union perf_event *event = data->event;
	struct perf_record_ksymbol *ksymbol;
	int len;

	ksymbol = &event->ksymbol;

	*ksymbol = (struct perf_record_ksymbol) {
		.header = {
			.type = PERF_RECORD_KSYMBOL,
			.size = offsetof(struct perf_record_ksymbol, name),
		},
		.addr      = addr,
		.len       = page_size,
		.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
		.flags     = 0,
	};

	len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name);
	ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64));
	memset((void *) event + event->header.size, 0, machine->id_hdr_size);
	event->header.size += machine->id_hdr_size;

	return perf_tool__process_synth_event(data->tool, event, machine,
					      data->process);
}

static int
kallsyms_process_symbol(void *data, const char *_name,
			char type __maybe_unused, u64 start)
{
	char disp[KSYM_NAME_LEN];
	char *module, *name;
	unsigned long id;
	int err = 0;

	module = strchr(_name, '\t');
	if (!module)
		return 0;

	/* We are going after [bpf] module ... */
	if (strcmp(module + 1, "[bpf]"))
		return 0;

	name = memdup(_name, (module - _name) + 1);
	if (!name)
		return -ENOMEM;

	name[module - _name] = 0;

	/* .. and only for trampolines and dispatchers */
	if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) ||
	    (sscanf(name, "bpf_dispatcher_%s", disp) == 1))
		err = process_bpf_image(name, start, data);

	free(name);
	return err;
}

int perf_event__synthesize_bpf_events(struct perf_session *session,
				      perf_event__handler_t process,
				      struct machine *machine,
				      struct record_opts *opts)
{
	const char *kallsyms_filename = "/proc/kallsyms";
	struct kallsyms_parse arg;
	union perf_event *event;
	__u32 id = 0;
	int err;
	int fd;

	if (opts->no_bpf_event)
		return 0;

	event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
	if (!event)
		return -1;

	/* Synthesize all the bpf programs in system. */
	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;
		}
	}

	/* Synthesize all the bpf images - trampolines/dispatchers. */
	if (symbol_conf.kallsyms_name != NULL)
		kallsyms_filename = symbol_conf.kallsyms_name;

	arg = (struct kallsyms_parse) {
		.event   = event,
		.process = process,
		.machine = machine,
		.tool    = session->tool,
	};

	if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) {
		pr_err("%s: failed to synthesize bpf images: %s\n",
		       __func__, strerror(errno));
	}

	free(event);
	return err;
}

static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
{
	struct bpf_prog_info_node *info_node;
	struct perf_bpil *info_linear;
	struct btf *btf = NULL;
	u64 arrays;
	u32 btf_id;
	int fd;

	fd = bpf_prog_get_fd_by_id(id);
	if (fd < 0)
		return;

	arrays = 1UL << PERF_BPIL_JITED_KSYMS;
	arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
	arrays |= 1UL << PERF_BPIL_FUNC_INFO;
	arrays |= 1UL << PERF_BPIL_PROG_TAGS;
	arrays |= 1UL << PERF_BPIL_JITED_INSNS;
	arrays |= 1UL << PERF_BPIL_LINE_INFO;
	arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;

	info_linear = get_bpf_prog_info_linear(fd, arrays);
	if (IS_ERR_OR_NULL(info_linear)) {
		pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
		goto out;
	}

	btf_id = info_linear->info.btf_id;

	info_node = malloc(sizeof(struct bpf_prog_info_node));
	if (info_node) {
		info_node->info_linear = info_linear;
		perf_env__insert_bpf_prog_info(env, info_node);
	} else
		free(info_linear);

	if (btf_id == 0)
		goto out;

	btf = btf__load_from_kernel_by_id(btf_id);
	if (libbpf_get_error(btf)) {
		pr_debug("%s: failed to get BTF of id %u, aborting\n",
			 __func__, btf_id);
		goto out;
	}
	perf_env__fetch_btf(env, btf_id, btf);

out:
	btf__free(btf);
	close(fd);
}

static int bpf_event__sb_cb(union perf_event *event, void *data)
{
	struct perf_env *env = data;

	if (event->header.type != PERF_RECORD_BPF_EVENT)
		return -1;

	switch (event->bpf.type) {
	case PERF_BPF_EVENT_PROG_LOAD:
		perf_env__add_bpf_info(env, event->bpf.id);

	case PERF_BPF_EVENT_PROG_UNLOAD:
		/*
		 * Do not free bpf_prog_info and btf of the program here,
		 * as annotation still need them. They will be freed at
		 * the end of the session.
		 */
		break;
	default:
		pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
		break;
	}

	return 0;
}

int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env)
{
	struct perf_event_attr attr = {
		.type	          = PERF_TYPE_SOFTWARE,
		.config           = PERF_COUNT_SW_DUMMY,
		.sample_id_all    = 1,
		.watermark        = 1,
		.bpf_event        = 1,
		.size	   = sizeof(attr), /* to capture ABI version */
	};

	/*
	 * Older gcc versions don't support designated initializers, like above,
	 * for unnamed union members, such as the following:
	 */
	attr.wakeup_watermark = 1;

	return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
}

void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
				      struct perf_env *env,
				      FILE *fp)
{
	__u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
	__u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
	char name[KSYM_NAME_LEN];
	struct btf *btf = NULL;
	u32 sub_prog_cnt, i;

	sub_prog_cnt = info->nr_jited_ksyms;
	if (sub_prog_cnt != info->nr_prog_tags ||
	    sub_prog_cnt != info->nr_jited_func_lens)
		return;

	if (info->btf_id) {
		struct btf_node *node;

		node = __perf_env__find_btf(env, info->btf_id);
		if (node)
			btf = btf__new((__u8 *)(node->data),
				       node->data_size);
	}

	if (sub_prog_cnt == 1) {
		synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0);
		fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n",
			info->id, name, prog_addrs[0], prog_lens[0]);
		goto out;
	}

	fprintf(fp, "# bpf_prog_info %u:\n", info->id);
	for (i = 0; i < sub_prog_cnt; i++) {
		synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i);

		fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n",
			i, name, prog_addrs[i], prog_lens[i]);
	}
out:
	btf__free(btf);
}
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>
943930e4 JO	9	#include <linux/string.h>
	10	#include <internal/lib.h>
	11	#include <symbol/kallsyms.h>
45178a92	12	#include "bpf-event.h"
6ac22d03	13	#include "bpf-utils.h"
45178a92	14	#include "debug.h"
4a3cec84	15	#include "dso.h"
45178a92	16	#include "symbol.h"
811184fb	17	#include "machine.h"
e4378f0c	18	#include "env.h"
e5416950	19	#include "session.h"
3ca3877a	20	#include "map.h"
d56354dc	21	#include "evlist.h"
aeb00b1a	22	#include "record.h"
ea49e01c	23	#include "util/synthetic-events.h"
45178a92	24
7b612e29 SL	25	static int snprintf_hex(char buf, size_t size, unsigned char data, size_t len)
	26	{
	27	int ret = 0;
	28	size_t i;
	29
	30	for (i = 0; i < len; i++)
	31	ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
	32	return ret;
	33	}
	34
3ca3877a SL	35	static int machine__process_bpf_event_load(struct machine *machine,
	36	union perf_event *event,
	37	struct perf_sample *sample __maybe_unused)
	38	{
3ca3877a SL	39	struct bpf_prog_info_node *info_node;
3ca3877a SL	40	struct perf_env *env = machine->env;
6ac22d03	41	struct perf_bpil *info_linear;
6a1b3598	42	int id = event->bpf.id;
3ca3877a SL	43	unsigned int i;
	44
	45	/* perf-record, no need to handle bpf-event */
	46	if (env == NULL)
	47	return 0;
	48
	49	info_node = perf_env__find_bpf_prog_info(env, id);
	50	if (!info_node)
	51	return 0;
	52	info_linear = info_node->info_linear;
	53
	54	for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
6987561c	55	u64 addrs = (u64 )(uintptr_t)(info_linear->info.jited_ksyms);
3ca3877a	56	u64 addr = addrs[i];
1a97cee6	57	struct map *map = maps__find(machine__kernel_maps(machine), addr);
3ca3877a SL	58
3ca3877a SL	59	if (map) {
63df0e4b IR	60	struct dso *dso = map__dso(map);
63df0e4b IR	61
ee756ef7 IR	62	dso__set_binary_type(dso, DSO_BINARY_TYPE__BPF_PROG_INFO);
	63	dso__bpf_prog(dso)->id = id;
	64	dso__bpf_prog(dso)->sub_id = i;
	65	dso__bpf_prog(dso)->env = env;
42fd623b	66	map__put(map);
3ca3877a SL	67	}
	68	}
	69	return 0;
	70	}
	71
3f604b5f ACM	72	int machine__process_bpf(struct machine machine, union perf_event event,
3f604b5f ACM	73	struct perf_sample *sample)
45178a92 SL	74	{
45178a92 SL	75	if (dump_trace)
3f604b5f	76	perf_event__fprintf_bpf(event, stdout);
3ca3877a	77
6a1b3598	78	switch (event->bpf.type) {
3ca3877a SL	79	case PERF_BPF_EVENT_PROG_LOAD:
	80	return machine__process_bpf_event_load(machine, event, sample);
	81
	82	case PERF_BPF_EVENT_PROG_UNLOAD:
	83	/*
	84	* Do not free bpf_prog_info and btf of the program here,
	85	* as annotation still need them. They will be freed at
	86	* the end of the session.
	87	*/
	88	break;
	89	default:
3f604b5f	90	pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
3ca3877a SL	91	break;
3ca3877a SL	92	}
45178a92 SL	93	return 0;
45178a92 SL	94	}
7b612e29	95
3792cb2f SL	96	static int perf_env__fetch_btf(struct perf_env *env,
	97	u32 btf_id,
	98	struct btf *btf)
	99	{
	100	struct btf_node *node;
	101	u32 data_size;
	102	const void *data;
	103
2502e74b	104	data = btf__raw_data(btf, &data_size);
3792cb2f SL	105
	106	node = malloc(data_size + sizeof(struct btf_node));
	107	if (!node)
	108	return -1;
	109
	110	node->id = btf_id;
	111	node->data_size = data_size;
	112	memcpy(node->data, data, data_size);
	113
4924b1f7 IR	114	if (!perf_env__insert_btf(env, node)) {
	115	/* Insertion failed because of a duplicate. */
	116	free(node);
	117	return -1;
	118	}
3792cb2f SL	119	return 0;
	120	}
	121
fc462ac7 SL	122	static int synthesize_bpf_prog_name(char *buf, int size,
	123	struct bpf_prog_info *info,
	124	struct btf *btf,
	125	u32 sub_id)
	126	{
	127	u8 (prog_tags)[BPF_TAG_SIZE] = (void )(uintptr_t)(info->prog_tags);
	128	void func_infos = (void )(uintptr_t)(info->func_info);
	129	u32 sub_prog_cnt = info->nr_jited_ksyms;
	130	const struct bpf_func_info *finfo;
	131	const char *short_name = NULL;
	132	const struct btf_type *t;
	133	int name_len;
	134
	135	name_len = snprintf(buf, size, "bpf_prog_");
	136	name_len += snprintf_hex(buf + name_len, size - name_len,
	137	prog_tags[sub_id], BPF_TAG_SIZE);
	138	if (btf) {
	139	finfo = func_infos + sub_id * info->func_info_rec_size;
	140	t = btf__type_by_id(btf, finfo->type_id);
	141	short_name = btf__name_by_offset(btf, t->name_off);
	142	} else if (sub_id == 0 && sub_prog_cnt == 1) {
	143	/* no subprog */
	144	if (info->name[0])
	145	short_name = info->name;
	146	} else
	147	short_name = "F";
	148	if (short_name)
	149	name_len += snprintf(buf + name_len, size - name_len,
	150	"_%s", short_name);
	151	return name_len;
	152	}
	153
7b612e29 SL	154	/*
	155	* Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
	156	* program. One PERF_RECORD_BPF_EVENT is generated for the program. And
	157	* one PERF_RECORD_KSYMBOL is generated for each sub program.
	158	*
	159	* Returns:
	160	* 0 for success;
	161	* -1 for failures;
	162	* -2 for lack of kernel support.
	163	*/
e5416950	164	static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
7b612e29 SL	165	perf_event__handler_t process,
	166	struct machine *machine,
	167	int fd,
	168	union perf_event *event,
	169	struct record_opts *opts)
	170	{
ebdba16e	171	struct perf_record_ksymbol *ksymbol_event = &event->ksymbol;
6a1b3598	172	struct perf_record_bpf_event *bpf_event = &event->bpf;
e5416950	173	struct perf_tool *tool = session->tool;
e4378f0c	174	struct bpf_prog_info_node *info_node;
6ac22d03	175	struct perf_bpil *info_linear;
a742258a	176	struct bpf_prog_info *info;
7b612e29	177	struct btf *btf = NULL;
e4378f0c	178	struct perf_env *env;
a742258a	179	u32 sub_prog_cnt, i;
7b612e29	180	int err = 0;
a742258a	181	u64 arrays;
7b612e29	182
e4378f0c SL	183	/*
	184	* for perf-record and perf-report use header.env;
	185	* otherwise, use global perf_env.
	186	*/
	187	env = session->data ? &session->header.env : &perf_env;
	188
6ac22d03 DM	189	arrays = 1UL << PERF_BPIL_JITED_KSYMS;
	190	arrays \|= 1UL << PERF_BPIL_JITED_FUNC_LENS;
	191	arrays \|= 1UL << PERF_BPIL_FUNC_INFO;
	192	arrays \|= 1UL << PERF_BPIL_PROG_TAGS;
	193	arrays \|= 1UL << PERF_BPIL_JITED_INSNS;
	194	arrays \|= 1UL << PERF_BPIL_LINE_INFO;
	195	arrays \|= 1UL << PERF_BPIL_JITED_LINE_INFO;
7b612e29	196
6ac22d03	197	info_linear = get_bpf_prog_info_linear(fd, arrays);
a742258a SL	198	if (IS_ERR_OR_NULL(info_linear)) {
	199	info_linear = NULL;
	200	pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
7b612e29 SL	201	return -1;
7b612e29 SL	202	}
a742258a SL	203
a742258a SL	204	if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
1a096ae4	205	free(info_linear);
7b612e29 SL	206	pr_debug("%s: the kernel is too old, aborting\n", __func__);
	207	return -2;
	208	}
	209
a742258a	210	info = &info_linear->info;
1a096ae4 JL	211	if (!info->jited_ksyms) {
	212	free(info_linear);
	213	return -1;
	214	}
a742258a	215
7b612e29	216	/* number of ksyms, func_lengths, and tags should match */
a742258a SL	217	sub_prog_cnt = info->nr_jited_ksyms;
a742258a SL	218	if (sub_prog_cnt != info->nr_prog_tags \|\|
1a096ae4 JL	219	sub_prog_cnt != info->nr_jited_func_lens) {
1a096ae4 JL	220	free(info_linear);
7b612e29	221	return -1;
1a096ae4	222	}
7b612e29 SL	223
7b612e29 SL	224	/* check BTF func info support */
a742258a	225	if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
7b612e29	226	/* btf func info number should be same as sub_prog_cnt */
a742258a	227	if (sub_prog_cnt != info->nr_func_info) {
7b612e29	228	pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
1a096ae4 JL	229	free(info_linear);
1a096ae4 JL	230	return -1;
7b612e29	231	}
86f4b7f2 QM	232	btf = btf__load_from_kernel_by_id(info->btf_id);
86f4b7f2 QM	233	if (libbpf_get_error(btf)) {
a742258a SL	234	pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
a742258a SL	235	err = -1;
a742258a	236	goto out;
7b612e29	237	}
3792cb2f	238	perf_env__fetch_btf(env, info->btf_id, btf);
7b612e29 SL	239	}
7b612e29 SL	240
7b612e29 SL	241	/* Synthesize PERF_RECORD_KSYMBOL */
7b612e29 SL	242	for (i = 0; i < sub_prog_cnt; i++) {
fc462ac7	243	__u32 prog_lens = (__u32 )(uintptr_t)(info->jited_func_lens);
a742258a	244	__u64 prog_addrs = (__u64 )(uintptr_t)(info->jited_ksyms);
7b612e29 SL	245	int name_len;
7b612e29 SL	246
69d81f09	247	*ksymbol_event = (struct perf_record_ksymbol) {
7b612e29 SL	248	.header = {
7b612e29 SL	249	.type = PERF_RECORD_KSYMBOL,
69d81f09	250	.size = offsetof(struct perf_record_ksymbol, name),
7b612e29 SL	251	},
	252	.addr = prog_addrs[i],
	253	.len = prog_lens[i],
	254	.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
	255	.flags = 0,
	256	};
7b612e29	257
fc462ac7 SL	258	name_len = synthesize_bpf_prog_name(ksymbol_event->name,
fc462ac7 SL	259	KSYM_NAME_LEN, info, btf, i);
7b612e29 SL	260	ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
7b612e29 SL	261	sizeof(u64));
811184fb SL	262
	263	memset((void *)event + event->header.size, 0, machine->id_hdr_size);
	264	event->header.size += machine->id_hdr_size;
7b612e29 SL	265	err = perf_tool__process_synth_event(tool, event,
	266	machine, process);
	267	}
	268
71184c6a	269	if (!opts->no_bpf_event) {
e4378f0c	270	/* Synthesize PERF_RECORD_BPF_EVENT */
69d81f09	271	*bpf_event = (struct perf_record_bpf_event) {
7b612e29 SL	272	.header = {
7b612e29 SL	273	.type = PERF_RECORD_BPF_EVENT,
69d81f09	274	.size = sizeof(struct perf_record_bpf_event),
7b612e29 SL	275	},
	276	.type = PERF_BPF_EVENT_PROG_LOAD,
	277	.flags = 0,
a742258a	278	.id = info->id,
7b612e29	279	};
a742258a	280	memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
811184fb SL	281	memset((void *)event + event->header.size, 0, machine->id_hdr_size);
811184fb SL	282	event->header.size += machine->id_hdr_size;
e4378f0c SL	283
	284	/* save bpf_prog_info to env */
	285	info_node = malloc(sizeof(struct bpf_prog_info_node));
	286	if (!info_node) {
	287	err = -1;
	288	goto out;
	289	}
	290
	291	info_node->info_linear = info_linear;
	292	perf_env__insert_bpf_prog_info(env, info_node);
	293	info_linear = NULL;
	294
	295	/*
	296	* process after saving bpf_prog_info to env, so that
	297	* required information is ready for look up
	298	*/
7b612e29 SL	299	err = perf_tool__process_synth_event(tool, event,
	300	machine, process);
	301	}
	302
	303	out:
a742258a	304	free(info_linear);
369e955b	305	btf__free(btf);
7b612e29 SL	306	return err ? -1 : 0;
	307	}
	308
943930e4 JO	309	struct kallsyms_parse {
	310	union perf_event *event;
	311	perf_event__handler_t process;
	312	struct machine *machine;
	313	struct perf_tool *tool;
	314	};
	315
	316	static int
	317	process_bpf_image(char name, u64 addr, struct kallsyms_parse data)
	318	{
	319	struct machine *machine = data->machine;
	320	union perf_event *event = data->event;
	321	struct perf_record_ksymbol *ksymbol;
	322	int len;
	323
	324	ksymbol = &event->ksymbol;
	325
	326	*ksymbol = (struct perf_record_ksymbol) {
	327	.header = {
	328	.type = PERF_RECORD_KSYMBOL,
	329	.size = offsetof(struct perf_record_ksymbol, name),
	330	},
	331	.addr = addr,
	332	.len = page_size,
	333	.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
	334	.flags = 0,
	335	};
	336
	337	len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name);
	338	ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64));
	339	memset((void *) event + event->header.size, 0, machine->id_hdr_size);
	340	event->header.size += machine->id_hdr_size;
	341
	342	return perf_tool__process_synth_event(data->tool, event, machine,
	343	data->process);
	344	}
	345
	346	static int
	347	kallsyms_process_symbol(void data, const char _name,
	348	char type __maybe_unused, u64 start)
	349	{
	350	char disp[KSYM_NAME_LEN];
	351	char module, name;
	352	unsigned long id;
	353	int err = 0;
	354
	355	module = strchr(_name, '\t');
	356	if (!module)
	357	return 0;
	358
	359	/* We are going after [bpf] module ... */
	360	if (strcmp(module + 1, "[bpf]"))
	361	return 0;
	362
	363	name = memdup(_name, (module - _name) + 1);
	364	if (!name)
	365	return -ENOMEM;
	366
	367	name[module - _name] = 0;
	368
	369	/* .. and only for trampolines and dispatchers */
	370	if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) \|\|
	371	(sscanf(name, "bpf_dispatcher_%s", disp) == 1))
	372	err = process_bpf_image(name, start, data);
373
374	free(name);
375	return err;
376	}
377
e5416950	378	int perf_event__synthesize_bpf_events(struct perf_session *session,
7b612e29 SL	379	perf_event__handler_t process,
	380	struct machine *machine,
	381	struct record_opts *opts)
	382	{
943930e4 JO	383	const char *kallsyms_filename = "/proc/kallsyms";
943930e4 JO	384	struct kallsyms_parse arg;
7b612e29 SL	385	union perf_event *event;
	386	__u32 id = 0;
	387	int err;
	388	int fd;
	389
6512b6aa IR	390	if (opts->no_bpf_event)
	391	return 0;
	392
6a1b3598	393	event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
7b612e29 SL	394	if (!event)
7b612e29 SL	395	return -1;
943930e4 JO	396
943930e4 JO	397	/* Synthesize all the bpf programs in system. */
7b612e29 SL	398	while (true) {
	399	err = bpf_prog_get_next_id(id, &id);
	400	if (err) {
	401	if (errno == ENOENT) {
	402	err = 0;
	403	break;
	404	}
b20fe106	405	pr_debug("%s: can't get next program: %s%s\n",
7b612e29 SL	406	__func__, strerror(errno),
7b612e29 SL	407	errno == EINVAL ? " -- kernel too old?" : "");
39f4a913 SL	408	/* don't report error on old kernel or EPERM */
39f4a913 SL	409	err = (errno == EINVAL \|\| errno == EPERM) ? 0 : -1;
7b612e29 SL	410	break;
	411	}
	412	fd = bpf_prog_get_fd_by_id(id);
	413	if (fd < 0) {
	414	pr_debug("%s: failed to get fd for prog_id %u\n",
	415	__func__, id);
	416	continue;
	417	}
	418
e5416950	419	err = perf_event__synthesize_one_bpf_prog(session, process,
7b612e29 SL	420	machine, fd,
	421	event, opts);
	422	close(fd);
	423	if (err) {
	424	/* do not return error for old kernel */
	425	if (err == -2)
	426	err = 0;
	427	break;
	428	}
	429	}
943930e4 JO	430
	431	/* Synthesize all the bpf images - trampolines/dispatchers. */
	432	if (symbol_conf.kallsyms_name != NULL)
	433	kallsyms_filename = symbol_conf.kallsyms_name;
	434
	435	arg = (struct kallsyms_parse) {
	436	.event = event,
	437	.process = process,
	438	.machine = machine,
	439	.tool = session->tool,
	440	};
	441
	442	if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) {
	443	pr_err("%s: failed to synthesize bpf images: %s\n",
	444	__func__, strerror(errno));
	445	}
	446
7b612e29 SL	447	free(event);
	448	return err;
	449	}
d56354dc SL	450
	451	static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
	452	{
d56354dc	453	struct bpf_prog_info_node *info_node;
6ac22d03	454	struct perf_bpil *info_linear;
d56354dc SL	455	struct btf *btf = NULL;
	456	u64 arrays;
	457	u32 btf_id;
	458	int fd;
	459
	460	fd = bpf_prog_get_fd_by_id(id);
	461	if (fd < 0)
	462	return;
	463
6ac22d03 DM	464	arrays = 1UL << PERF_BPIL_JITED_KSYMS;
	465	arrays \|= 1UL << PERF_BPIL_JITED_FUNC_LENS;
	466	arrays \|= 1UL << PERF_BPIL_FUNC_INFO;
	467	arrays \|= 1UL << PERF_BPIL_PROG_TAGS;
	468	arrays \|= 1UL << PERF_BPIL_JITED_INSNS;
	469	arrays \|= 1UL << PERF_BPIL_LINE_INFO;
	470	arrays \|= 1UL << PERF_BPIL_JITED_LINE_INFO;
d56354dc	471
6ac22d03	472	info_linear = get_bpf_prog_info_linear(fd, arrays);
d56354dc SL	473	if (IS_ERR_OR_NULL(info_linear)) {
	474	pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
	475	goto out;
	476	}
	477
	478	btf_id = info_linear->info.btf_id;
	479
	480	info_node = malloc(sizeof(struct bpf_prog_info_node));
	481	if (info_node) {
	482	info_node->info_linear = info_linear;
	483	perf_env__insert_bpf_prog_info(env, info_node);
	484	} else
	485	free(info_linear);
	486
	487	if (btf_id == 0)
	488	goto out;
	489
86f4b7f2 QM	490	btf = btf__load_from_kernel_by_id(btf_id);
86f4b7f2 QM	491	if (libbpf_get_error(btf)) {
d56354dc SL	492	pr_debug("%s: failed to get BTF of id %u, aborting\n",
	493	__func__, btf_id);
	494	goto out;
	495	}
	496	perf_env__fetch_btf(env, btf_id, btf);
	497
	498	out:
369e955b	499	btf__free(btf);
d56354dc SL	500	close(fd);
	501	}
	502
	503	static int bpf_event__sb_cb(union perf_event event, void data)
	504	{
	505	struct perf_env *env = data;
	506
	507	if (event->header.type != PERF_RECORD_BPF_EVENT)
	508	return -1;
	509
6a1b3598	510	switch (event->bpf.type) {
d56354dc	511	case PERF_BPF_EVENT_PROG_LOAD:
6a1b3598	512	perf_env__add_bpf_info(env, event->bpf.id);
d56354dc SL	513
	514	case PERF_BPF_EVENT_PROG_UNLOAD:
	515	/*
	516	* Do not free bpf_prog_info and btf of the program here,
	517	* as annotation still need them. They will be freed at
	518	* the end of the session.
	519	*/
	520	break;
	521	default:
3f604b5f	522	pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
d56354dc SL	523	break;
	524	}
	525
	526	return 0;
	527	}
	528
b38d85ef	529	int evlist__add_bpf_sb_event(struct evlist evlist, struct perf_env env)
d56354dc SL	530	{
	531	struct perf_event_attr attr = {
	532	.type = PERF_TYPE_SOFTWARE,
	533	.config = PERF_COUNT_SW_DUMMY,
	534	.sample_id_all = 1,
	535	.watermark = 1,
	536	.bpf_event = 1,
	537	.size = sizeof(attr), /* to capture ABI version */
	538	};
	539
	540	/*
	541	* Older gcc versions don't support designated initializers, like above,
	542	* for unnamed union members, such as the following:
	543	*/
	544	attr.wakeup_watermark = 1;
	545
08c83997	546	return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
d56354dc	547	}
f8dfeae0	548
9c51f878 IR	549	void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
	550	struct perf_env *env,
	551	FILE *fp)
f8dfeae0 SL	552	{
	553	__u32 prog_lens = (__u32 )(uintptr_t)(info->jited_func_lens);
	554	__u64 prog_addrs = (__u64 )(uintptr_t)(info->jited_ksyms);
	555	char name[KSYM_NAME_LEN];
	556	struct btf *btf = NULL;
	557	u32 sub_prog_cnt, i;
	558
	559	sub_prog_cnt = info->nr_jited_ksyms;
	560	if (sub_prog_cnt != info->nr_prog_tags \|\|
	561	sub_prog_cnt != info->nr_jited_func_lens)
	562	return;
	563
	564	if (info->btf_id) {
	565	struct btf_node *node;
	566
9c51f878	567	node = __perf_env__find_btf(env, info->btf_id);
f8dfeae0 SL	568	if (node)
	569	btf = btf__new((__u8 *)(node->data),
	570	node->data_size);
	571	}
	572
	573	if (sub_prog_cnt == 1) {
	574	synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0);
	575	fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n",
	576	info->id, name, prog_addrs[0], prog_lens[0]);
88c42f4d	577	goto out;
f8dfeae0 SL	578	}
	579
	580	fprintf(fp, "# bpf_prog_info %u:\n", info->id);
	581	for (i = 0; i < sub_prog_cnt; i++) {
	582	synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i);
	583
	584	fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n",
	585	i, name, prog_addrs[i], prog_lens[i]);
	586	}
88c42f4d IR	587	out:
88c42f4d IR	588	btf__free(btf);
f8dfeae0	589	}