From: Jan Beulich <jbeulich@suse.com>
To: Juergen Gross <jgross@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jirislaby@kernel.org>,
xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2] xen/hvc: replace BUG_ON() with negative return value
Date: Wed, 7 Jul 2021 11:57:37 +0200 [thread overview]
Message-ID: <9e45c5f8-0ac0-e1bb-4703-838679285e80@suse.com> (raw)
In-Reply-To: <20210707091045.460-1-jgross@suse.com>
On 07.07.2021 11:10, Juergen Gross wrote:
> Xen frontends shouldn't BUG() in case of illegal data received from
> their backends. So replace the BUG_ON()s when reading illegal data from
> the ring page with negative return values.
>
> Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
> --- a/drivers/tty/hvc/hvc_xen.c
> +++ b/drivers/tty/hvc/hvc_xen.c
> @@ -86,7 +86,11 @@ static int __write_console(struct xencons_info *xencons,
> cons = intf->out_cons;
> prod = intf->out_prod;
> mb(); /* update queue values before going on */
Largely unrelated note: While in general the barriers here may want
switching to virt_*mb(), this particular one looks to be too heavy
anyway: a read barrier is all that's needed here afaict, just like
there's only a write barrier between ring contents and producer
writing in __write_console().
And btw, since I've got puzzled by the linuxppc-dev@ in the recipients
list, I did look up relevant entries in ./MAINTAINERS. Shouldn't the
file be part of "XEN HYPERVISOR INTERFACE"?
Jan
next prev parent reply other threads:[~2021-07-07 9:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 9:10 [PATCH v2] xen/hvc: replace BUG_ON() with negative return value Juergen Gross
2021-07-07 9:57 ` Jan Beulich [this message]
2021-07-07 10:40 ` Juergen Gross
2021-07-07 10:58 ` Jiri Slaby
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