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Commit 14c9b31a authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Arnaldo Carvalho de Melo
Browse files

perf header: Fix lock/unlock imbalances when processing BPF/BTF info 



Fix lock/unlock imbalances by refactoring the code a bit and adding
calls to up_write() before return.

Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Addresses-Coverity-ID: 1444315 ("Missing unlock")
Addresses-Coverity-ID: 1444316 ("Missing unlock")
Fixes: a70a1123 ("perf bpf: Save BTF information as headers to perf.data")
Fixes: 606f972b ("perf bpf: Save bpf_prog_info information as headers to perf.data")
Link: http://lkml.kernel.org/r/20190408173355.GA10501@embeddedor


[ Simplified the exit path to have just one up_write() + return ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 9d5dcc93

tools/perf/util/header.c

+13 −9
Original line number Diff line number Diff line
@@ -2606,6 +2606,7 @@ static int process_bpf_prog_info(struct feat_fd *ff, void *data __maybe_unused) 
		perf_env__insert_bpf_prog_info(env, info_node);

	}



	up_write(&env->bpf_progs.lock);

	return 0;

out:

	free(info_linear);
@@ -2623,7 +2624,9 @@ static int process_bpf_prog_info(struct feat_fd *ff __maybe_unused, void *data _ 
static int process_bpf_btf(struct feat_fd *ff, void *data __maybe_unused)

{

	struct perf_env *env = &ff->ph->env;

	struct btf_node *node = NULL;

	u32 count, i;

	int err = -1;



	if (ff->ph->needs_swap) {

		pr_warning("interpreting btf from systems with endianity is not yet supported\n");
@@ -2636,31 +2639,32 @@ static int process_bpf_btf(struct feat_fd *ff, void *data __maybe_unused) 
	down_write(&env->bpf_progs.lock);



	for (i = 0; i < count; ++i) {

		struct btf_node *node;

		u32 id, data_size;



		if (do_read_u32(ff, &id))

			return -1;

			goto out;

		if (do_read_u32(ff, &data_size))

			return -1;

			goto out;



		node = malloc(sizeof(struct btf_node) + data_size);

		if (!node)

			return -1;

			goto out;



		node->id = id;

		node->data_size = data_size;



		if (__do_read(ff, node->data, data_size)) {

			free(node);

			return -1;

		}

		if (__do_read(ff, node->data, data_size))

			goto out;



		perf_env__insert_btf(env, node);

		node = NULL;

	}



	err = 0;

out:

	up_write(&env->bpf_progs.lock);

	return 0;

	free(node);

	return err;

}



struct feature_ops {