btf contains information necessary to annotate bpf programs. This patch
saves btf for bpf programs loaded in the system.
perf-record saves btf information as headers to perf.data. A new header
type HEADER_BTF is introduced for this data.
Signed-off-by: Song Liu <songliubrav...@fb.com>
---
tools/perf/util/bpf-event.c | 22 +++++++++
tools/perf/util/bpf-event.h | 7 +++
tools/perf/util/env.c | 65 ++++++++++++++++++++++++
tools/perf/util/env.h | 3 ++
tools/perf/util/header.c | 99 ++++++++++++++++++++++++++++++++++++-
tools/perf/util/header.h | 1 +
6 files changed, 196 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index ead599bc4f4e..37a5b8134e00 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -30,6 +30,27 @@ int machine__process_bpf_event(struct machine *machine
__maybe_unused,
return 0;
}
+static int perf_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
@@ -109,6 +130,7 @@ static int perf_event__synthesize_one_bpf_prog(struct
perf_session *session,
goto out;
}
has_btf = true;
+ perf_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 11e6730b6105..60ce24e4e5c6 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -20,6 +20,13 @@ 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 665b6fe3c7b2..6f9e3d4b94bc 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -61,6 +61,57 @@ 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_info_lock);
+ p = &env->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);
+ up_write(&env->bpf_info_lock);
+ return;
+ }
+ }
+
+ rb_link_node(&btf_node->rb_node, parent, p);
+ rb_insert_color(&btf_node->rb_node, &env->btfs);
+ up_write(&env->bpf_info_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_info_lock);
+ n = env->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_info_lock);
+ return node;
+}
+
/* purge data in bpf_prog_infos tree */
static void purge_bpf_info(struct perf_env *env)
{
@@ -80,6 +131,19 @@ static void purge_bpf_info(struct perf_env *env)
rb_erase_init(&node->rb_node, root);
free(node);
}
+
+ root = &env->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_init(&node->rb_node, root);
+ free(node);
+ }
+
up_write(&env->bpf_info_lock);
}
@@ -117,6 +181,7 @@ void perf_env__exit(struct perf_env *env)
static void init_bpf_rb_trees(struct perf_env *env)
{
env->bpf_prog_infos = RB_ROOT;
+ env->btfs = RB_ROOT;
init_rwsem(&env->bpf_info_lock);
}
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 5894a177b7cf..40b6e9413c22 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -69,6 +69,7 @@ struct perf_env {
u64 clockid_res_ns;
struct rw_semaphore bpf_info_lock;
struct rb_root bpf_prog_infos;
+ struct rb_root btfs;
};
extern struct perf_env perf_env;
@@ -89,4 +90,6 @@ 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 */
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 2ae76a9d06f6..3f1562afe8e5 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1125,6 +1125,45 @@ static int write_bpf_prog_info(struct feat_fd *ff,
return ret;
}
+static int write_btf(struct feat_fd *ff,
+ struct perf_evlist *evlist __maybe_unused)
+{
+ struct perf_env *env = &ff->ph->env;
+ struct rb_root *root;
+ struct rb_node *next;
+ u32 count = 0;
+ int ret;
+
+ down_read(&env->bpf_info_lock);
+
+ root = &env->btfs;
+ next = rb_first(root);
+ while (next) {
+ ++count;
+ next = rb_next(next);
+ }
+
+ ret = do_write(ff, &count, sizeof(count));
+
+ if (ret < 0)
+ goto out;
+
+ 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);
+ ret = do_write(ff, node,
+ sizeof(struct btf_node) + node->data_size);
+ if (ret < 0)
+ goto out;
+ }
+out:
+ up_read(&env->bpf_info_lock);
+ return ret;
+}
+
static int cpu_cache_level__sort(const void *a, const void *b)
{
struct cpu_cache_level *cache_a = (struct cpu_cache_level *)a;
@@ -1628,6 +1667,28 @@ static void print_bpf_prog_info(struct feat_fd *ff, FILE
*fp)
up_read(&env->bpf_info_lock);
}
+static void print_btf(struct feat_fd *ff, FILE *fp)
+{
+ struct perf_env *env = &ff->ph->env;
+ struct rb_root *root;
+ struct rb_node *next;
+
+ down_read(&env->bpf_info_lock);
+
+ root = &env->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);
+ fprintf(fp, "# bpf_prog_info of id %u\n", node->id);
+ }
+
+ up_read(&env->bpf_info_lock);
+}
+
static void free_event_desc(struct perf_evsel *events)
{
struct perf_evsel *evsel;
@@ -2723,6 +2784,41 @@ static int process_bpf_prog_info(struct feat_fd *ff,
return err;
}
+static int process_btf(struct feat_fd *ff, void *data __maybe_unused)
+{
+ struct perf_env *env = &ff->ph->env;
+ u32 count, i;
+
+ if (do_read_u32(ff, &count))
+ return -1;
+
+ down_write(&env->bpf_info_lock);
+
+ for (i = 0; i < count; ++i) {
+ struct btf_node btf_node;
+ struct btf_node *node;
+
+ if (__do_read(ff, &btf_node, sizeof(struct btf_node)))
+ return -1;
+
+ node = malloc(sizeof(struct btf_node) + btf_node.data_size);
+ if (!node)
+ return -1;
+
+ node->id = btf_node.id;
+ node->data_size = btf_node.data_size;
+
+ if (__do_read(ff, node->data, btf_node.data_size)) {
+ free(node);
+ return -1;
+ }
+ perf_env__insert_btf(env, node);
+ }
+
+ up_write(&env->bpf_info_lock);
+ return 0;
+}
+
struct feature_ops {
int (*write)(struct feat_fd *ff, struct perf_evlist *evlist);
void (*print)(struct feat_fd *ff, FILE *fp);
@@ -2783,7 +2879,8 @@ static const struct feature_ops
feat_ops[HEADER_LAST_FEATURE] = {
FEAT_OPR(SAMPLE_TIME, sample_time, false),
FEAT_OPR(MEM_TOPOLOGY, mem_topology, true),
FEAT_OPR(CLOCKID, clockid, false),
- FEAT_OPR(BPF_PROG_INFO, bpf_prog_info, false)
+ FEAT_OPR(BPF_PROG_INFO, bpf_prog_info, false),
+ FEAT_OPR(BTF, btf, false)
};
struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 0785c91b4c3a..ba51d8e43c53 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -40,6 +40,7 @@ enum {
HEADER_MEM_TOPOLOGY,
HEADER_CLOCKID,
HEADER_BPF_PROG_INFO,
+ HEADER_BTF,
HEADER_LAST_FEATURE,
HEADER_FEAT_BITS = 256,
};
--
2.17.1
