Add variants of perf_env__insert_bpf_prog_info, perf_env__insert_btf and perf_env__find_btf prefixed with __ to indicate the env->bpf_progs.lock is assumed held. Call these variants when the lock is held to avoid recursively taking it and potentially having a thread deadlock with itself. Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx> --- Previously this patch was part of a larger set: https://lore.kernel.org/lkml/20231127220902.1315692-51-irogers@xxxxxxxxxx/ --- tools/perf/util/bpf-event.c | 8 +++--- tools/perf/util/bpf-event.h | 12 ++++----- tools/perf/util/env.c | 53 +++++++++++++++++++++++-------------- tools/perf/util/env.h | 4 +++ tools/perf/util/header.c | 8 +++--- 5 files changed, 51 insertions(+), 34 deletions(-) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 830711cae30d..3573e0b7ef3e 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -545,9 +545,9 @@ int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) return 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) +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); @@ -563,7 +563,7 @@ void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, if (info->btf_id) { struct btf_node *node; - node = perf_env__find_btf(env, info->btf_id); + node = __perf_env__find_btf(env, info->btf_id); if (node) btf = btf__new((__u8 *)(node->data), node->data_size); diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h index 1bcbd4fb6c66..e2f0420905f5 100644 --- a/tools/perf/util/bpf-event.h +++ b/tools/perf/util/bpf-event.h @@ -33,9 +33,9 @@ struct btf_node { int machine__process_bpf(struct machine *machine, union perf_event *event, struct perf_sample *sample); int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env); -void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, - struct perf_env *env, - FILE *fp); +void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, + struct perf_env *env, + FILE *fp); #else static inline int machine__process_bpf(struct machine *machine __maybe_unused, union perf_event *event __maybe_unused, @@ -50,9 +50,9 @@ static inline int evlist__add_bpf_sb_event(struct evlist *evlist __maybe_unused, return 0; } -static inline void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info __maybe_unused, - struct perf_env *env __maybe_unused, - FILE *fp __maybe_unused) +static inline void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info __maybe_unused, + struct perf_env *env __maybe_unused, + FILE *fp __maybe_unused) { } diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c index c68b7a004f29..cfdacbf29456 100644 --- a/tools/perf/util/env.c +++ b/tools/perf/util/env.c @@ -22,15 +22,20 @@ struct perf_env perf_env; #include "bpf-utils.h" #include <bpf/libbpf.h> -void perf_env__insert_bpf_prog_info(struct perf_env *env, - struct bpf_prog_info_node *info_node) +void perf_env__insert_bpf_prog_info(struct perf_env *env, struct bpf_prog_info_node *info_node) +{ + down_write(&env->bpf_progs.lock); + __perf_env__insert_bpf_prog_info(env, info_node); + up_write(&env->bpf_progs.lock); +} + +void __perf_env__insert_bpf_prog_info(struct perf_env *env, struct bpf_prog_info_node *info_node) { __u32 prog_id = info_node->info_linear->info.id; struct bpf_prog_info_node *node; struct rb_node *parent = NULL; struct rb_node **p; - down_write(&env->bpf_progs.lock); p = &env->bpf_progs.infos.rb_node; while (*p != NULL) { @@ -42,15 +47,13 @@ void perf_env__insert_bpf_prog_info(struct perf_env *env, p = &(*p)->rb_right; } else { pr_debug("duplicated bpf prog info %u\n", prog_id); - goto out; + return; } } rb_link_node(&info_node->rb_node, parent, p); rb_insert_color(&info_node->rb_node, &env->bpf_progs.infos); env->bpf_progs.infos_cnt++; -out: - up_write(&env->bpf_progs.lock); } struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env, @@ -79,14 +82,22 @@ struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env, } bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node) +{ + bool ret; + + down_write(&env->bpf_progs.lock); + ret = __perf_env__insert_btf(env, btf_node); + up_write(&env->bpf_progs.lock); + return ret; +} + +bool __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; - bool ret = true; - down_write(&env->bpf_progs.lock); p = &env->bpf_progs.btfs.rb_node; while (*p != NULL) { @@ -98,25 +109,31 @@ bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node) p = &(*p)->rb_right; } else { pr_debug("duplicated btf %u\n", btf_id); - ret = false; - goto out; + return false; } } 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); - return ret; + return true; } struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id) +{ + struct btf_node *res; + + down_read(&env->bpf_progs.lock); + res = __perf_env__find_btf(env, btf_id); + up_read(&env->bpf_progs.lock); + return res; +} + +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) { @@ -126,13 +143,9 @@ struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id) else if (btf_id > node->id) n = n->rb_right; else - goto out; + return node; } - node = NULL; - -out: - up_read(&env->bpf_progs.lock); - return node; + return NULL; } /* purge data in bpf_progs.infos tree */ diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h index bf7e3c4c211f..7c527e65c186 100644 --- a/tools/perf/util/env.h +++ b/tools/perf/util/env.h @@ -175,12 +175,16 @@ 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); +void __perf_env__insert_bpf_prog_info(struct perf_env *env, + struct bpf_prog_info_node *info_node); 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); 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); 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, diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 08cc2febabde..02bf9d8b5f74 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1849,8 +1849,8 @@ static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp) node = rb_entry(next, struct bpf_prog_info_node, rb_node); next = rb_next(&node->rb_node); - bpf_event__print_bpf_prog_info(&node->info_linear->info, - env, fp); + __bpf_event__print_bpf_prog_info(&node->info_linear->info, + env, fp); } up_read(&env->bpf_progs.lock); @@ -3188,7 +3188,7 @@ static int process_bpf_prog_info(struct feat_fd *ff, void *data __maybe_unused) /* after reading from file, translate offset to address */ bpil_offs_to_addr(info_linear); info_node->info_linear = info_linear; - perf_env__insert_bpf_prog_info(env, info_node); + __perf_env__insert_bpf_prog_info(env, info_node); } up_write(&env->bpf_progs.lock); @@ -3235,7 +3235,7 @@ static int process_bpf_btf(struct feat_fd *ff, void *data __maybe_unused) if (__do_read(ff, node->data, data_size)) goto out; - perf_env__insert_btf(env, node); + __perf_env__insert_btf(env, node); node = NULL; } -- 2.43.0.rc2.451.g8631bc7472-goog
