| Message ID | 20220405000553.21856-1-xiam0nd.tong@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [RESEND,v2] myri10ge: remove an unneeded NULL check | expand |
On Tue, 5 Apr 2022 08:05:53 +0800 Xiaomeng Tong wrote: > The define of skb_list_walk_safe(first, skb, next_skb) is: > for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \ > (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL) > > Thus, if the 'segs' passed as 'first' into the skb_list_walk_safe is NULL, > the loop will exit immediately. In other words, it can be sure the 'segs' > is non-NULL when we run inside the loop. So just remove the unnecessary > NULL check. Also remove the unneeded assignmnets. > > Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> The existing code is pretty clearly buggy. Please fix the bugs or don't touch it. You're obfuscating what the original intention was. > diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c > index 50ac3ee2577a..071657e3dba8 100644 > --- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c > +++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c > @@ -2903,12 +2903,8 @@ static netdev_tx_t myri10ge_sw_tso(struct sk_buff *skb, > status = myri10ge_xmit(curr, dev); > if (status != 0) { > dev_kfree_skb_any(curr); > - if (segs != NULL) { > - curr = segs; > - segs = next; > - curr->next = NULL; > - dev_kfree_skb_any(segs); > - } > + segs->next = NULL; > + dev_kfree_skb_any(next); > goto drop; > } > }
diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c index 50ac3ee2577a..071657e3dba8 100644 --- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c +++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c @@ -2903,12 +2903,8 @@ static netdev_tx_t myri10ge_sw_tso(struct sk_buff *skb, status = myri10ge_xmit(curr, dev); if (status != 0) { dev_kfree_skb_any(curr); - if (segs != NULL) { - curr = segs; - segs = next; - curr->next = NULL; - dev_kfree_skb_any(segs); - } + segs->next = NULL; + dev_kfree_skb_any(next); goto drop; } }
The define of skb_list_walk_safe(first, skb, next_skb) is: for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \ (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL) Thus, if the 'segs' passed as 'first' into the skb_list_walk_safe is NULL, the loop will exit immediately. In other words, it can be sure the 'segs' is non-NULL when we run inside the loop. So just remove the unnecessary NULL check. Also remove the unneeded assignmnets. Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> --- changes since v1: - remove the unneeded assignmnets. v1: https://lore.kernel.org/lkml/20220319052350.26535-1-xiam0nd.tong@gmail.com/ --- drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)