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Re: [Qemu-devel] [PATCH 2/4] s390x/css: fix NULL handling for CCW addres
From: |
Cornelia Huck |
Subject: |
Re: [Qemu-devel] [PATCH 2/4] s390x/css: fix NULL handling for CCW addresses |
Date: |
Mon, 11 Sep 2017 11:44:34 +0200 |
On Fri, 8 Sep 2017 17:24:44 +0200
Halil Pasic <address@hidden> wrote:
> Back then in the time of df1fe5bb49 ("s390: Virtual channel subsystem
> support.", 2013-01-24) -EIO used to map to a channel-program check (via
> the default label of the switch statement). Then 2dc95b4cac
> ("s390x/3270: 3270 data stream handling", 2016-04-01) came along
> and that changed dramatically.
>
> Let us roll back this undesired side effect, and go back to
> channel-program check.
>
> Signed-off-by: Halil Pasic <address@hidden>
> Fixes: 2dc95b4cac "s390x/3270: 3270 data stream handling"
> ---
>
> I'm not sure 0 as CCW address it's strictly illegal. Yes 0 is an
> unlikely address for a CCW but I would appreciate a PoP reference
> clarifying this...
0 is not an address we can fetch from, I think that is enough to
trigger a channel-program check.
>
> Another reason to not use Unix/POSIX error codes like this.
> ---
> hw/s390x/css.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 09f6ba0310..a44d87ab3e 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -793,7 +793,7 @@ static int css_interpret_ccw(SubchDev *sch, hwaddr
> ccw_addr,
> CCW1 ccw;
>
> if (!ccw_addr) {
> - return -EIO;
> + return -EINVAL; /* channel-program check */
> }
> /* Check doubleword aligned and 31 or 24 (fmt 0) bit addressable. */
> if (ccw_addr & (sch->ccw_fmt_1 ? 0x80000007 : 0xff000007)) {
Thanks, queued.