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net: add and use skb_unclone_keeptruesize() helper

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While commit 097b9146c0 ("net: fix up truesize of cloned
skb in skb_prepare_for_shift()") fixed immediate issues found
when KFENCE was enabled/tested, there are still similar issues,
when tcp_trim_head() hits KFENCE while the master skb
is cloned.

This happens under heavy networking TX workloads,
when the TX completion might be delayed after incoming ACK.

This patch fixes the WARNING in sk_stream_kill_queues
when sk->sk_mem_queued/sk->sk_forward_alloc are not zero.

Fixes: d3fb45f370 ("mm, kfence: insert KFENCE hooks for SLAB")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20211102004555.1359210-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet
2021-11-01 17:45:55 -07:00
committed by Jakub Kicinski
parent 236f57fe1b
commit c4777efa75
3 changed files with 20 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
net/ipv4/tcp_output.c
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@@ -1559,7 +1559,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
return -ENOMEM;
}
if (skb_unclone(skb, gfp))
if (skb_unclone_keeptruesize(skb, gfp))
return -ENOMEM;
/* Get a new skb... force flag on. */
@@ -1667,7 +1667,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
{
u32 delta_truesize;
if (skb_unclone(skb, GFP_ATOMIC))
if (skb_unclone_keeptruesize(skb, GFP_ATOMIC))
return -ENOMEM;
delta_truesize = __pskb_trim_head(skb, len);
@@ -3166,7 +3166,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
cur_mss, GFP_ATOMIC))
return -ENOMEM; /* We'll try again later. */
} else {
if (skb_unclone(skb, GFP_ATOMIC))
if (skb_unclone_keeptruesize(skb, GFP_ATOMIC))
return -ENOMEM;
diff = tcp_skb_pcount(skb);