libbpf: Fix perf_buffer__free() API for sparse allocs

[ 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>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index cd53204d33f0c77d7e9001aad2d5b2a37bb17c23..0c5b4fb553fbca01d60906e2f8b81b2ba2fdfdf2 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7809,9 +7809,12 @@ 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);
                }