Commit fdc3441f authored by Blake Jones's avatar Blake Jones Committed by Namhyung Kim
Browse files

perf record: collect BPF metadata from new programs 



This collects metadata for any BPF programs that were loaded during a
"perf record" run, and emits it at the end of the run.

Signed-off-by: default avatarBlake Jones <blakejones@google.com>
Link: https://lore.kernel.org/r/20250612194939.162730-4-blakejones@google.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent ab38e84b

tools/perf/builtin-record.c

+10 −0
Original line number Diff line number Diff line
@@ -2162,6 +2162,14 @@ static int record__synthesize(struct record *rec, bool tail) 
	return err;

}



static void record__synthesize_final_bpf_metadata(struct record *rec __maybe_unused)

{

#ifdef HAVE_LIBBPF_SUPPORT

	perf_event__synthesize_final_bpf_metadata(rec->session,

						  process_synthesized_event);

#endif

}



static int record__process_signal_event(union perf_event *event __maybe_unused, void *data)

{

	struct record *rec = data;
@@ -2807,6 +2815,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) 
	trigger_off(&auxtrace_snapshot_trigger);

	trigger_off(&switch_output_trigger);



	record__synthesize_final_bpf_metadata(rec);



	if (opts->auxtrace_snapshot_on_exit)

		record__auxtrace_snapshot_exit(rec);

tools/perf/util/bpf-event.c

+46 −0
Original line number Diff line number Diff line
@@ -472,6 +472,49 @@ void bpf_metadata_free(struct bpf_metadata *metadata __maybe_unused) 


#endif /* HAVE_LIBBPF_STRINGS_SUPPORT */



struct bpf_metadata_final_ctx {

	const struct perf_tool *tool;

	perf_event__handler_t process;

	struct machine *machine;

};



static void synthesize_final_bpf_metadata_cb(struct bpf_prog_info_node *node,

					     void *data)

{

	struct bpf_metadata_final_ctx *ctx = (struct bpf_metadata_final_ctx *)data;

	struct bpf_metadata *metadata = node->metadata;

	int err;



	if (metadata == NULL)

		return;

	err = synthesize_perf_record_bpf_metadata(metadata, ctx->tool,

						  ctx->process, ctx->machine);

	if (err != 0) {

		const char *prog_name = metadata->prog_names[0];



		if (prog_name != NULL)

			pr_warning("Couldn't synthesize final BPF metadata for %s.\n", prog_name);

		else

			pr_warning("Couldn't synthesize final BPF metadata.\n");

	}

	bpf_metadata_free(metadata);

	node->metadata = NULL;

}



void perf_event__synthesize_final_bpf_metadata(struct perf_session *session,

					       perf_event__handler_t process)

{

	struct perf_env *env = &session->header.env;

	struct bpf_metadata_final_ctx ctx = {

		.tool = session->tool,

		.process = process,

		.machine = &session->machines.host,

	};



	perf_env__iterate_bpf_prog_info(env, synthesize_final_bpf_metadata_cb,

					&ctx);

}



/*

 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf

 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
@@ -612,6 +655,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, 
		}



		info_node->info_linear = info_linear;

		info_node->metadata = NULL;

		if (!perf_env__insert_bpf_prog_info(env, info_node)) {

			free(info_linear);

			free(info_node);
@@ -803,6 +847,7 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id) 
	arrays |= 1UL << PERF_BPIL_JITED_INSNS;

	arrays |= 1UL << PERF_BPIL_LINE_INFO;

	arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;

	arrays |= 1UL << PERF_BPIL_MAP_IDS;



	info_linear = get_bpf_prog_info_linear(fd, arrays);

	if (IS_ERR_OR_NULL(info_linear)) {
@@ -815,6 +860,7 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id) 
	info_node = malloc(sizeof(struct bpf_prog_info_node));

	if (info_node) {

		info_node->info_linear = info_linear;

		info_node->metadata = bpf_metadata_create(&info_linear->info);

		if (!perf_env__insert_bpf_prog_info(env, info_node)) {

			free(info_linear);

			free(info_node);

tools/perf/util/bpf-event.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ struct bpf_metadata { 


struct bpf_prog_info_node {

	struct perf_bpil		*info_linear;

	struct bpf_metadata		*metadata;

	struct rb_node			rb_node;

};

tools/perf/util/env.c

+18 −1
Original line number Diff line number Diff line
@@ -3,8 +3,10 @@ 
#include "debug.h"

#include "env.h"

#include "util/header.h"

#include "linux/compiler.h"

#include "util/rwsem.h"

#include <linux/compiler.h>

#include <linux/ctype.h>

#include <linux/rbtree.h>

#include <linux/string.h>

#include <linux/zalloc.h>

#include "cgroup.h"
@@ -89,6 +91,20 @@ struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env, 
	return node;

}



void perf_env__iterate_bpf_prog_info(struct perf_env *env,

				     void (*cb)(struct bpf_prog_info_node *node,

						void *data),

				     void *data)

{

	struct rb_node *first;



	down_read(&env->bpf_progs.lock);

	first = rb_first(&env->bpf_progs.infos);

	for (struct rb_node *node = first; node != NULL; node = rb_next(node))

		(*cb)(rb_entry(node, struct bpf_prog_info_node, rb_node), data);

	up_read(&env->bpf_progs.lock);

}



bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node)

{

	bool ret;
@@ -174,6 +190,7 @@ static void perf_env__purge_bpf(struct perf_env *env) 
		next = rb_next(&node->rb_node);

		rb_erase(&node->rb_node, root);

		zfree(&node->info_linear);

		bpf_metadata_free(node->metadata);

		free(node);

	}

tools/perf/util/env.h

+6 −0
Original line number Diff line number Diff line
@@ -174,16 +174,22 @@ const char *perf_env__raw_arch(struct perf_env *env); 
int perf_env__nr_cpus_avail(struct perf_env *env);



void perf_env__init(struct perf_env *env);

#ifdef HAVE_LIBBPF_SUPPORT

bool __perf_env__insert_bpf_prog_info(struct perf_env *env,

				      struct bpf_prog_info_node *info_node);

bool perf_env__insert_bpf_prog_info(struct perf_env *env,

				    struct bpf_prog_info_node *info_node);

struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,

							__u32 prog_id);

void perf_env__iterate_bpf_prog_info(struct perf_env *env,

				     void (*cb)(struct bpf_prog_info_node *node,

						void *data),

				     void *data);

bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node);

bool __perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node);

struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id);

struct btf_node *__perf_env__find_btf(struct perf_env *env, __u32 btf_id);

#endif // HAVE_LIBBPF_SUPPORT



int perf_env__numa_node(struct perf_env *env, struct perf_cpu cpu);

char *perf_env__find_pmu_cap(struct perf_env *env, const char *pmu_name,