This is a note to let you know that I've just added the patch titled
bpf: iter_udp: Retry with a larger batch size without going back to the previous bucket
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-iter_udp-retry-with-a-larger-batch-size-without-.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d36f244d894b8ac7e1c5aa92cecfa5cbfd47f849
Author: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Date: Fri Jan 12 11:05:28 2024 -0800
bpf: iter_udp: Retry with a larger batch size without going back to the previous bucket
[ Upstream commit 19ca0823f6eaad01d18f664a00550abe912c034c ]
The current logic is to use a default size 16 to batch the whole bucket.
If it is too small, it will retry with a larger batch size.
The current code accidentally does a state->bucket-- before retrying.
This goes back to retry with the previous bucket which has already
been done. This patch fixed it.
It is hard to create a selftest. I added a WARN_ON(state->bucket < 0),
forced a particular port to be hashed to the first bucket,
created >16 sockets, and observed the for-loop went back
to the "-1" bucket.
Cc: Aditi Ghag <aditi.ghag@xxxxxxxxxxxxx>
Fixes: c96dac8d369f ("bpf: udp: Implement batching for sockets iterator")
Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx>
Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Reviewed-by: Aditi Ghag <aditi.ghag@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240112190530.3751661-2-martin.lau@xxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5f742d0b9e07..79050d83e736 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -3213,7 +3213,6 @@ static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
/* After allocating a larger batch, retry one more time to grab
* the whole bucket.
*/
- state->bucket--;
goto again;
}
done:
