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| author | Eric Dumazet <edumazet@google.com> | 2021-11-01 17:45:55 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-11-02 18:10:34 -0700 |
| commit | c4777efa751d293e369aec464ce6875e957be255 (patch) | |
| tree | 88c4cb6d3fa42b985c17ef59447197a32c9a7128 /include/linux/skbuff.h | |
| parent | 236f57fe1b8853fb3505502c0f94ae64d153ae92 (diff) | |
| download | lwn-c4777efa751d293e369aec464ce6875e957be255.tar.gz lwn-c4777efa751d293e369aec464ce6875e957be255.zip | |
net: add and use skb_unclone_keeptruesize() helper
While commit 097b9146c0e2 ("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: d3fb45f370d9 ("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>
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 0bd6520329f6..a63e13082397 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1675,6 +1675,22 @@ static inline int skb_unclone(struct sk_buff *skb, gfp_t pri) return 0; } +/* This variant of skb_unclone() makes sure skb->truesize is not changed */ +static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri) +{ + might_sleep_if(gfpflags_allow_blocking(pri)); + + if (skb_cloned(skb)) { + unsigned int save = skb->truesize; + int res; + + res = pskb_expand_head(skb, 0, 0, pri); + skb->truesize = save; + return res; + } + return 0; +} + /** * skb_header_cloned - is the header a clone * @skb: buffer to check |