Re: [PATCH v14 07/11] io_uring/zcrx: set pp memory provider for an rx queue

[Kees Bakker <kees@ijzerbout.nl>]

Op 15-02-2025 om 01:09 schreef David Wei:
> Set the page pool memory provider for the rx queue configured for zero
> copy to io_uring. Then the rx queue is reset using
> netdev_rx_queue_restart() and netdev core + page pool will take care of
> filling the rx queue from the io_uring zero copy memory provider.
>
> For now, there is only one ifq so its destruction happens implicitly
> during io_uring cleanup.
>
> Reviewed-by: Jens Axboe <axboe@kernel.dk>
> Signed-off-by: David Wei <dw@davidwei.uk>
> ---
>   io_uring/zcrx.c | 49 +++++++++++++++++++++++++++++++++++++++++--------
>   1 file changed, 41 insertions(+), 8 deletions(-)
>
> diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
> index 8833879d94ba..7d24fc98b306 100644
> --- a/io_uring/zcrx.c
> +++ b/io_uring/zcrx.c
> [...]
> @@ -444,6 +475,8 @@ void io_shutdown_zcrx_ifqs(struct io_ring_ctx *ctx)
>   
>   	if (ctx->ifq)
>   		io_zcrx_scrub(ctx->ifq);
> +
> +	io_close_queue(ctx->ifq);
If ctx->ifq is NULL (which seems to be not unlikely given the if 
statement above)
then you'll get a NULL pointer dereference in io_close_queue().
>   }
>   
>   static inline u32 io_zcrx_rqring_entries(struct io_zcrx_ifq *ifq)