1 files changed, 480 insertions, 0 deletions

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
new file mode 100644
index 000000000000..2a4a0da35632
--- /dev/null
+++ b/tools/perf/util/bpf-event.c
@@ -0,0 +1,480 @@
+// 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"
+#include "map.h"
+#include "evlist.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;
+}
+
+static int machine__process_bpf_event_load(struct machine *machine,
+					   union perf_event *event,
+					   struct perf_sample *sample __maybe_unused)
+{
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_info_node *info_node;
+	struct perf_env *env = machine->env;
+	int id = event->bpf_event.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;
+
+		map = map_groups__find(&machine->kmaps, addr);
+
+		if (map) {
+			map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
+			map->dso->bpf_prog.id = id;
+			map->dso->bpf_prog.sub_id = i;
+			map->dso->bpf_prog.env = env;
+		}
+	}
+	return 0;
+}
+
+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);
+
+	switch (event->bpf_event.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_event.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__get_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);
+
+	perf_env__insert_btf(env, node);
+	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 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;
+	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;
+		}
+		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 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 = 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 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;
+}
+
+static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
+{
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_info_node *info_node;
+	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 << 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)) {
+		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;
+
+	if (btf__get_from_id(btf_id, &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:
+	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_event.type) {
+	case PERF_BPF_EVENT_PROG_LOAD:
+		perf_env__add_bpf_info(env, event->bpf_event.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_event.type);
+		break;
+	}
+
+	return 0;
+}
+
+int bpf_event__add_sb_event(struct perf_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 perf_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]);
+		return;
+	}
+
+	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]);
+	}
+}