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Subject[PATCH 1/2] perf bpf: Avoid memory leak from perf_env__insert_btf
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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.

Fixes: 3792cb2ff43b ("perf bpf: Save BTF in a rbtree in perf_env")
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/bpf-event.c | 5 ++++-
tools/perf/util/env.c | 5 ++++-
tools/perf/util/env.h | 2 +-
3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 1a7112a87736..0783b464777a 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -120,7 +120,10 @@ 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 0;
}

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index cf773f0dec38..5b24eb010336 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -74,12 +74,13 @@ 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;
@@ -93,6 +94,7 @@ 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;
}
}
@@ -102,6 +104,7 @@ 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)
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 1383876f72b3..163e5ec503a2 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -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);
--
2.34.0.rc0.344.g81b53c2807-goog
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