wireguard: queueing: use saner cpu selection wrapping

commit 7387943fa35516f6f8017a3b0e9ce48a3bef9faa upstream.

Using `% nr_cpumask_bits` is slow and complicated, and not totally
robust toward dynamic changes to CPU topologies. Rather than storing the
next CPU in the round-robin, just store the last one, and also return
that value. This simplifies the loop drastically into a much more common
pattern.

Fixes: e7096c131e ("net: WireGuard secure network tunnel")
Cc: stable@vger.kernel.org
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Manuel Leiner <manuel.leiner@gmx.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jason A. Donenfeld
2023-07-03 03:27:04 +02:00
committed by Greg Kroah-Hartman
parent ea21392224
commit 1b71070405
4 changed files with 14 additions and 16 deletions

View File

@@ -28,6 +28,7 @@ int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,
int ret;
memset(queue, 0, sizeof(*queue));
queue->last_cpu = -1;
ret = ptr_ring_init(&queue->ring, len, GFP_KERNEL);
if (ret)
return ret;