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Commit 4cd5db4f authored by Ian Rogers's avatar Ian Rogers Committed by Greg Kroah-Hartman
Browse files

perf env: Avoid recursively taking env->bpf_progs.lock 



[ Upstream commit 9c51f8788b5d4e9f46afbcf563255cfd355690b3 ]

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.

Fixes: f8dfeae0 ("perf bpf: Show more BPF program info in print_bpf_prog_info()")
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarSong Liu <song@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ming Wang <wangming01@loongson.cn>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20231207014655.1252484-1-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent f19a1cb1

tools/perf/util/bpf-event.c

+4 −4
Original line number Diff line number Diff line
@@ -442,7 +442,7 @@ int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) 
	return perf_evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);

}



void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,

void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,

				      struct perf_env *env,

				      FILE *fp)

{
@@ -460,7 +460,7 @@ 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);

tools/perf/util/bpf-event.h

+6 −6
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ 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,

void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,

				      struct perf_env *env,

				      FILE *fp);

#else
@@ -51,7 +51,7 @@ 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,

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)

{

tools/perf/util/env.c

+32 −18
Original line number Diff line number Diff line
@@ -15,13 +15,19 @@ struct perf_env perf_env; 


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) {
@@ -33,15 +39,13 @@ 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,
@@ -70,14 +74,22 @@ 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) {
@@ -89,25 +101,31 @@ 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) {
@@ -117,14 +135,10 @@ 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;

	}

	node = NULL;



out:

	up_read(&env->bpf_progs.lock);

			return node;

	}

	return NULL;

}



/* purge data in bpf_progs.infos tree */

static void perf_env__purge_bpf(struct perf_env *env)

tools/perf/util/env.h

+4 −0
Original line number Diff line number Diff line
@@ -117,12 +117,16 @@ 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, int cpu);

#endif /* __PERF_ENV_H */

tools/perf/util/header.c

+4 −4
Original line number Diff line number Diff line
@@ -1546,7 +1546,7 @@ 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,

		__bpf_event__print_bpf_prog_info(&node->info_linear->info,

						 env, fp);

	}
@@ -2724,7 +2724,7 @@ static int process_bpf_prog_info(struct feat_fd *ff, void *data __maybe_unused) 
		/* after reading from file, translate offset to address */

		bpf_program__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);
@@ -2777,7 +2777,7 @@ 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;

	}