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Message-ID: <47789946-0ffe-462e-9e2e-43b03ea41fe0@linux.ibm.com>
Date: Thu, 15 Feb 2024 14:36:57 +0100
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Subject: Re: [PATCH] net/af_iucv: fix virtual vs physical address confusion
Content-Language: en-US
To: Alexander Gordeev <agordeev@linux.ibm.com>,
        Thorsten Winkler <twinkler@linux.ibm.com>
Cc: linux-s390@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20240215080500.2616848-1-agordeev@linux.ibm.com>
From: Alexandra Winter <wintera@linux.ibm.com>
In-Reply-To: <20240215080500.2616848-1-agordeev@linux.ibm.com>
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On 15.02.24 09:05, Alexander Gordeev wrote:
> Fix virtual vs physical address confusion. This does not fix a bug
> since virtual and physical address spaces are currently the same.
> 
> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
> ---
>  net/iucv/af_iucv.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
> index 498a0c35b7bb..4aa1c72e6c49 100644
> --- a/net/iucv/af_iucv.c
> +++ b/net/iucv/af_iucv.c
> @@ -1060,13 +1060,12 @@ static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
>  			int i;
>  
>  			/* skip iucv_array lying in the headroom */
> -			iba[0].address = (u32)(addr_t)skb->data;
> +			iba[0].address = (u32)virt_to_phys(skb->data);
>  			iba[0].length = (u32)skb_headlen(skb);
>  			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
>  				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
>  
> -				iba[i + 1].address =
> -					(u32)(addr_t)skb_frag_address(frag);
> +				iba[i + 1].address = (u32)virt_to_phys(skb_frag_address(frag));
>  				iba[i + 1].length = (u32)skb_frag_size(frag);
>  			}
>  			err = pr_iucv->message_send(iucv->path, &txmsg,
> @@ -1162,13 +1161,12 @@ static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
>  			struct iucv_array *iba = (struct iucv_array *)skb->head;
>  			int i;
>  
> -			iba[0].address = (u32)(addr_t)skb->data;
> +			iba[0].address = (u32)virt_to_phys(skb->data);
>  			iba[0].length = (u32)skb_headlen(skb);
>  			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
>  				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
>  
> -				iba[i + 1].address =
> -					(u32)(addr_t)skb_frag_address(frag);
> +				iba[i + 1].address = (u32)virt_to_phys(skb_frag_address(frag));
>  				iba[i + 1].length = (u32)skb_frag_size(frag);
>  			}
>  			rc = pr_iucv->message_receive(path, msg,


Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>

I would have preferred to do all the translations in __iucv_* functions in iucv.c,
but I understand that for __iucv_message_receive() this would mean significant changes.