Re: [PATCH bpf-next] libbpf: fix perf_buffer__free() API for sparse allocs

On 27 May 2020, at 19:58, Andrii Nakryiko wrote:

On Wed, May 27, 2020 at 1:42 AM Eelco Chaudron [off-list ref] 
wrote:

quoted

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

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---

Thanks a lot!

You forgot:

Fixes: fb84b8224655 ("libbpf: add perf buffer API")

Thanks, I forgot that :(  Daniel do you want me to send a v2, or will 
you add it when you apply it?

Acked-by: Andrii Nakryiko <redacted>

quoted

 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 5d60de6fd818..74d967619dcf 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c

@@ -8137,9 +8137,12 @@ 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);
                }