[PATCH AUTOSEL 5.4 168/175] libbpf: Fix perf_buffer__free() API for sparse allocs

Sasha Levin
2020-06-09T00:01:25Z

From: Eelco Chaudron <echaudro@redhat.com>

[ Upstream commit 601b05ca6edb0422bf6ce313fbfd55ec7bbbc0fd ]

In case the cpu_bufs are sparsely allocated they are not all
free'ed. These changes will fix this.

Fixes: fb84b8224655 ("libbpf: add perf buffer API")
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/159056888305.330763.9684536967379110349.stgit@ebuild
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/lib/bpf/libbpf.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 281cc65276e0..2a1dbf52fc9a 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5358,9 +5358,12 @@ void perf_buffer__free(struct perf_buffer *pb)
if (!pb)
return;
if (pb->cpu_bufs) {
- for (i = 0; i < pb->cpu_cnt && pb->cpu_bufs[i]; i++) {
+ for (i = 0; i < pb->cpu_cnt; i++) {
struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];

+ if (!cpu_buf)
+ continue;
+
bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key);
perf_buffer__free_cpu_buf(pb, cpu_buf);
}
--
2.25.1