[lkml]   [2021]   [Jul]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 5.13 147/156] tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy path
From: Talal Ahmad <>

commit 358ed624207012f03318235017ac6fb41f8af592 upstream.

sk_wmem_schedule makes sure that sk_forward_alloc has enough
bytes for charging that is going to be done by sk_mem_charge.

In the transmit zerocopy path, there is sk_mem_charge but there was
no call to sk_wmem_schedule. This change adds that call.

Without this call to sk_wmem_schedule, sk_forward_alloc can go
negetive which is a bug because sk_forward_alloc is a per-socket
space that has been forward charged so this can't be negative.

Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Talal Ahmad <>
Reviewed-by: Willem de Bruijn <>
Reviewed-by: Wei Wang <>
Reviewed-by: Soheil Hassas Yeganeh <>
Signed-off-by: Eric Dumazet <>
Signed-off-by: David S. Miller <>
Signed-off-by: Greg Kroah-Hartman <>
net/ipv4/tcp.c | 3 +++
1 file changed, 3 insertions(+)

--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1375,6 +1375,9 @@ new_segment:
pfrag->offset += copy;
} else {
+ if (!sk_wmem_schedule(sk, copy))
+ goto wait_for_space;
err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
if (err == -EMSGSIZE || err == -EEXIST) {
tcp_mark_push(tp, skb);

 \ /
  Last update: 2021-07-22 19:34    [W:0.039 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site