path: root/kernel
diff options
authorJakub Kicinski <jakub.kicinski@netronome.com>2017-11-20 15:21:51 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2017-11-21 00:37:35 +0100
commit13a9c48a85ccf1417b527975c0a12b47fbfaf625 (patch)
treea86d9abcc840de3c4ce3b5a0ea7f9a25a8280e39 /kernel
parent32a72bbd5da2411eab591bf9bc2e39349106193a (diff)
bpf: offload: add comment warning developers about double destroy
Offload state may get destroyed either because the device for which it was constructed is going away, or because the refcount of bpf program itself has reached 0. In both of those cases we will call __bpf_prog_offload_destroy() to unlink the offload from the device. We may in fact call it twice, which works just fine, but we should make clear this is intended and caution others trying to extend the function. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel')
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 2816feb38be1..fd696d3dd429 100644
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -85,6 +85,10 @@ static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
struct bpf_dev_offload *offload = prog->aux->offload;
struct netdev_bpf data = {};
+ /* Caution - if netdev is destroyed before the program, this function
+ * will be called twice.
+ */
data.offload.prog = prog;
if (offload->verifier_running)

Privacy Policy