From: Juergen Gross <jgross@suse.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linuxppc-dev@lists.ozlabs.org, Jiri Slaby <jirislaby@kernel.org>,
linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
Subject: Re: [PATCH v2] xen/hvc: replace BUG_ON() with negative return value
Date: Wed, 7 Jul 2021 12:40:54 +0200 [thread overview]
Message-ID: <dd32b09b-7345-664b-165d-dfb30c285448@suse.com> (raw)
In-Reply-To: <9e45c5f8-0ac0-e1bb-4703-838679285e80@suse.com>
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On 07.07.21 11:57, Jan Beulich wrote:
> 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().
I agree.
> 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"?
I wouldn't mind. Greg, Jiri, what do you think?
Juergen
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next prev parent reply other threads:[~2021-07-07 10:41 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
2021-07-07 10:40 ` Juergen Gross [this message]
2021-07-07 10:58 ` Jiri Slaby
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