linux-kernel - Re: [PATCH] io_uring/rsrc: remove unnecessary check on resv2

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Message-ID: <b0b0db4c-ac91-482a-85a4-2acd2884e5ae@kernel.dk>
Date: Tue, 23 Sep 2025 02:50:47 -0600
From: Jens Axboe <axboe@...nel.dk>
To: clingfei <clf700383@...il.com>
Cc: io-uring@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] io_uring/rsrc: remove unnecessary check on resv2

On 9/23/25 2:41 AM, clingfei wrote:
> From b52509776e0f7f9ea703d0551ccaeeaa49ab6440 Mon Sep 17 00:00:00 2001
> From: clingfei <clf700383@...il.com>
> Date: Tue, 23 Sep 2025 16:30:30 +0800
> Subject: [PATCH] io_uring/rsrc: remove unnecessary check on resv2
> 
> The memset sets the up.resv2 to be 0,
> and the copy_from_user does not touch it,
> thus up.resv2 will always be false.

Please wrap commit messages at around ~72 chars.

> Signed-off-by: clingfei <clf700383@...il.com>
> ---
>  io_uring/rsrc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
> index f75f5e43fa4a..7006b3ca5404 100644
> --- a/io_uring/rsrc.c
> +++ b/io_uring/rsrc.c
> @@ -372,7 +372,7 @@ int io_register_files_update(struct io_ring_ctx
> *ctx, void __user *arg,
>     memset(&up, 0, sizeof(up));
>     if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
>         return -EFAULT;
> -   if (up.resv || up.resv2)
> +   if (up.resv)
>         return -EINVAL;
>     return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
>  }

White space damaged patch, but more importantly, I don't think this is
worth adding. Yes it'll never overwrite resv2 because of the different
sizes. Curious how you ran into this?

-- 
Jens Axboe