From 3792cb2ff43b1b193136a03ce1336462a827d792 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 11 Mar 2019 22:30:44 -0700 Subject: [PATCH] perf bpf: Save BTF in a rbtree in perf_env BTF contains information necessary to annotate BPF programs. This patch saves BTF for BPF programs loaded in the system. Signed-off-by: Song Liu Reviewed-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stanislav Fomichev Cc: kernel-team@fb.com Link: http://lkml.kernel.org/r/20190312053051.2690567-9-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/bpf-event.c | 23 +++++++++++++ tools/perf/util/bpf-event.h | 7 ++++ tools/perf/util/env.c | 67 +++++++++++++++++++++++++++++++++++++ tools/perf/util/env.h | 5 +++ 4 files changed, 102 insertions(+) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 37ee4e2a728a..a4fc52b4ffae 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 98cd36f0e317..c6351b557bb0 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) { @@ -86,6 +138,20 @@ static void perf_env__purge_bpf(struct perf_env *env) env->bpf_progs.infos_cnt = 0; + 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); + } + + env->bpf_progs.btfs_cnt = 0; + up_write(&env->bpf_progs.lock); } @@ -123,6 +189,7 @@ 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 */ -- GitLab