[PATCH net-next 2/5] net: always set reason in sk_filter_trim_cap()

[Eric Dumazet <edumazet@google.com>]

sk_filter_trim_cap() will soon return the drop reason by value.

Make sure *reason is cleared when no error is returned,
to ease this conversion.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-7 (-7)
Function                                     old     new   delta
sk_filter_trim_cap                           889     882      -7
Total: Before=29722668, After=29722661, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/core/filter.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index cf2113af4bc9ae7c976d7c55f3092643e1d875b6..5569d83b8be06dc1fe64ddff2ae338acd1622ed7 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -121,7 +121,7 @@ EXPORT_SYMBOL_GPL(copy_bpf_fprog_from_user);
  *	@sk: sock associated with &sk_buff
  *	@skb: buffer to filter
  *	@cap: limit on how short the eBPF program may trim the packet
- *	@reason: record drop reason on errors (negative return value)
+ *	@reason: record drop reason
  *
  * Run the eBPF program and then cut skb->data to correct size returned by
  * the program. If pkt_len is 0 we toss packet. If skb->len is smaller
@@ -168,11 +168,10 @@ int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb,
 		pkt_len = bpf_prog_run_save_cb(filter->prog, skb);
 		skb->sk = save_sk;
 		err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM;
-		if (err)
-			*reason = SKB_DROP_REASON_SOCKET_FILTER;
 	}
 	rcu_read_unlock();
 
+	*reason = err ? SKB_DROP_REASON_SOCKET_FILTER : 0;
 	return err;
 }
 EXPORT_SYMBOL(sk_filter_trim_cap);
-- 
2.53.0.1213.gd9a14994de-goog