On 11/14/2016 03:49 AM, Alexei Starovoitov wrote:
On Mon, Nov 14, 2016 at 01:43:41AM +0100, Daniel Borkmann wrote:
[...]
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 751e806..a0fca9f 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -682,6 +682,17 @@ struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i) } EXPORT_SYMBOL_GPL(bpf_prog_add);+void bpf_prog_sub(struct bpf_prog *prog, int i) +{ + /* Only to be used for undoing previous bpf_prog_add() in some + * error path. We still know that another entity in our call + * path holds a reference to the program, thus atomic_sub() can + * be safely used in such cases! + */ + WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0); +} +EXPORT_SYMBOL_GPL(bpf_prog_sub);the patches look good. I'm only worried about net/net-next merge conflict here. (I would have to deal with it as well). So instead of copying the above helper can we apply net-next's 'bpf, mlx4: fix prog refcount in mlx4_en_try_alloc_resources error path' patch to net without mlx4_xdp_set hunk and then apply the rest of this patch? Even better is to send this patch 2/3 to net-next? yes, it's an issue, but very small one. There is no security concern here, so I would prefer to avoid merge conflict. Did you do a test merge of net/net-next by any chance?
Yes, I did a test merge and git resolved the above just fine w/o any conflicts. I have no strong opinion whether net or net-next. If preferred, I can just resend this series in the evening against net-next instead, perhaps that's a bit better. Thanks, Daniel
