[SLOF] [PATCH v2 1/2] virtio-serial: Make read and write methods report failure

[Thomas Huth]

On 29/08/2023 02.12, Jordan Niethe wrote:
> From: Kautuk Consul <kconsul at linux.vnet.ibm.com>
> 
> The read and write methods return successfully even if the virtio device
> is closed (virtiodev is 0) and it is not able to send or receive any
> characters.
> 
> Make the read and write methods return 0 to indicate they did not
> succeed in this case.
> 
> This also fixes an invalid stack access in the read method.
> 
> Fixes: 8174acd ("virtio-serial: Close device completely")
> Signed-off-by: Kautuk Consul <kconsul at linux.vnet.ibm.com>
> Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
> ---
> v2:
>     - Rework commit message slightly
> ---
>   board-qemu/slof/virtio-serial.fs | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/board-qemu/slof/virtio-serial.fs b/board-qemu/slof/virtio-serial.fs
> index 82868e2..41e2e04 100644
> --- a/board-qemu/slof/virtio-serial.fs
> +++ b/board-qemu/slof/virtio-serial.fs
> @@ -67,7 +67,7 @@ virtiodev virtio-serial-init drop
>   ;
>   
>   : write ( addr len -- actual )
> -    virtiodev 0= IF nip EXIT THEN
> +    virtiodev 0= IF 2drop 0 EXIT THEN
>       tuck
>       0 ?DO
>           dup c@ virtiodev SWAP virtio-serial-putchar
> @@ -78,7 +78,7 @@ virtiodev virtio-serial-init drop
>   
>   : read ( addr len -- actual )
>       0= IF drop 0 EXIT THEN
> -    virtiodev 0= IF nip EXIT THEN
> +    virtiodev 0= IF drop 0 EXIT THEN
>       virtiodev virtio-serial-haschar 0= IF 0 swap c! -2 EXIT THEN
>       virtiodev virtio-serial-getchar swap c! 1
>   ;

Reviewed-by: Thomas Huth <thuth at redhat.com>