Commit 4924b1f7 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
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perf bpf: Avoid memory leak from perf_env__insert_btf() 



perf_env__insert_btf() doesn't insert if a duplicate BTF id is
encountered and this causes a memory leak. Modify the function to return
a success/error value and then free the memory if insertion didn't
happen.

v2. Adds a return -1 when the insertion error occurs in
    perf_env__fetch_btf. This doesn't affect anything as the result is
    never checked.

Fixes: 3792cb2f ("perf bpf: Save BTF in a rbtree in perf_env")
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211112074525.121633-1-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 4f74f187

tools/perf/util/bpf-event.c

+5 −1
Original line number Diff line number Diff line
@@ -119,7 +119,11 @@ static int perf_env__fetch_btf(struct perf_env *env, 
	node->data_size = data_size;

	memcpy(node->data, data, data_size);



	perf_env__insert_btf(env, node);

	if (!perf_env__insert_btf(env, node)) {

		/* Insertion failed because of a duplicate. */

		free(node);

		return -1;

	}

	return 0;

}

tools/perf/util/env.c

+4 −1
Original line number Diff line number Diff line
@@ -75,12 +75,13 @@ 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)

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;
@@ -94,6 +95,7 @@ void 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;

		}

	}
@@ -103,6 +105,7 @@ void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node) 
	env->bpf_progs.btfs_cnt++;

out:

	up_write(&env->bpf_progs.lock);

	return ret;

}



struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)

tools/perf/util/env.h

+1 −1
Original line number Diff line number Diff line
@@ -167,7 +167,7 @@ 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);

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);



int perf_env__numa_node(struct perf_env *env, int cpu);