diff mbox series

[v9,perf,bpf,08/15] perf, bpf: save btf in a rbtree in perf_env

Message ID 20190312053051.2690567-9-songliubraving@fb.com
State Awaiting Upstream
Delegated to: BPF Maintainers
Headers show
Series perf annotation of BPF programs | expand

Commit Message

Song Liu March 12, 2019, 5:30 a.m. UTC 
btf contains information necessary to annotate bpf programs. This patch
saves btf for bpf programs loaded in the system.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/bpf-event.c | 23 +++++++++++++
 tools/perf/util/bpf-event.h |  7 ++++
 tools/perf/util/env.c       | 66 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/env.h       |  5 +++
 4 files changed, 101 insertions(+)

Comments

Arnaldo Carvalho de Melo March 12, 2019, 3 p.m. UTC | #1 
Em Mon, Mar 11, 2019 at 10:30:44PM -0700, Song Liu escreveu:
>  static void perf_env__purge_bpf(struct perf_env *env)
>  {
> @@ -83,6 +135,19 @@ static void perf_env__purge_bpf(struct perf_env *env)
>  		rb_erase(&node->rb_node, root);
>  		free(node);
>  	}
> +
> +	root = &env->bpf_progs.btfs;
> +	next = rb_first(root);
> +
> +	while (next) {
> +		struct btf_node *node;
> +
> +		node = rb_entry(next, struct btf_node, rb_node);
> +		next = rb_next(&node->rb_node);
> +		rb_erase(&node->rb_node, root);
> +		free(node);
> +	}

Added this as well:

	env->bpf_progs.btfs_cnt = 0;

> +
>  	up_write(&env->bpf_progs.lock);
>  }
diff mbox series

Patch

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 9013f7c29761..e02a38a98d8d 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -34,6 +34,28 @@  int machine__process_bpf_event(struct machine *machine __maybe_unused,
 	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;
+}
+
 /*
  * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
  * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
@@ -113,6 +135,7 @@  static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 			goto out;
 		}
 		has_btf = true;
+		perf_env__fetch_btf(env, info->btf_id, btf);
 	}
 
 	/* Synthesize PERF_RECORD_KSYMBOL */
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index fad932f7404f..b9ec394dc7c7 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -16,6 +16,13 @@  struct bpf_prog_info_node {
 	struct rb_node			rb_node;
 };
 
+struct btf_node {
+	struct rb_node	rb_node;
+	u32		id;
+	u32		data_size;
+	char		data[];
+};
+
 #ifdef HAVE_LIBBPF_SUPPORT
 int machine__process_bpf_event(struct machine *machine, union perf_event *event,
 			       struct perf_sample *sample);
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index fb82623b0822..84bdf726c6a1 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -64,6 +64,58 @@  struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
 	return node;
 }
 
+void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node)
+{
+	struct rb_node *parent = NULL;
+	__u32 btf_id = btf_node->id;
+	struct btf_node *node;
+	struct rb_node **p;
+
+	down_write(&env->bpf_progs.lock);
+	p = &env->bpf_progs.btfs.rb_node;
+
+	while (*p != NULL) {
+		parent = *p;
+		node = rb_entry(parent, struct btf_node, rb_node);
+		if (btf_id < node->id) {
+			p = &(*p)->rb_left;
+		} else if (btf_id > node->id) {
+			p = &(*p)->rb_right;
+		} else {
+			pr_debug("duplicated btf %u\n", btf_id);
+			goto out;
+		}
+	}
+
+	rb_link_node(&btf_node->rb_node, parent, p);
+	rb_insert_color(&btf_node->rb_node, &env->bpf_progs.btfs);
+	env->bpf_progs.btfs_cnt++;
+out:
+	up_write(&env->bpf_progs.lock);
+}
+
+struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
+{
+	struct btf_node *node = NULL;
+	struct rb_node *n;
+
+	down_read(&env->bpf_progs.lock);
+	n = env->bpf_progs.btfs.rb_node;
+
+	while (n) {
+		node = rb_entry(n, struct btf_node, rb_node);
+		if (btf_id < node->id)
+			n = n->rb_left;
+		else if (btf_id > node->id)
+			n = n->rb_right;
+		else
+			break;
+	}
+
+	up_read(&env->bpf_progs.lock);
+	return node;
+}
+
 /* purge data in bpf_progs.infos tree */
 static void perf_env__purge_bpf(struct perf_env *env)
 {
@@ -83,6 +135,19 @@  static void perf_env__purge_bpf(struct perf_env *env)
 		rb_erase(&node->rb_node, root);
 		free(node);
 	}
+
+	root = &env->bpf_progs.btfs;
+	next = rb_first(root);
+
+	while (next) {
+		struct btf_node *node;
+
+		node = rb_entry(next, struct btf_node, rb_node);
+		next = rb_next(&node->rb_node);
+		rb_erase(&node->rb_node, root);
+		free(node);
+	}
+
 	up_write(&env->bpf_progs.lock);
 }
 
@@ -120,6 +185,7 @@  void perf_env__exit(struct perf_env *env)
 void perf_env__init(struct perf_env *env)
 {
 	env->bpf_progs.infos = RB_ROOT;
+	env->bpf_progs.btfs = RB_ROOT;
 	init_rwsem(&env->bpf_progs.lock);
 }
 
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 24b11c564ba4..4f8e2b485c01 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -75,10 +75,13 @@  struct perf_env {
 		struct rw_semaphore	lock;
 		struct rb_root		infos;
 		u32			infos_cnt;
+		struct rb_root		btfs;
+		u32			btfs_cnt;
 	} bpf_progs;
 };
 
 struct bpf_prog_info_node;
+struct btf_node;
 
 extern struct perf_env perf_env;
 
@@ -99,4 +102,6 @@  void 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__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);
 #endif /* __PERF_ENV_H */