Re: [PATCH 8/8] xen/hvc: replace BUG_ON() with negative return value

[Juergen Gross <jgross@suse.com>]

[-- Attachment #1.1.1: Type: text/plain, Size: 1232 bytes --]

On 13.05.21 12:16, Christophe Leroy wrote:
> 
> 
> Le 13/05/2021 à 12:03, Juergen Gross a écrit :
>> 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>
>> ---
>>   drivers/tty/hvc/hvc_xen.c | 15 +++++++++++++--
>>   1 file changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
>> index 92c9a476defc..30d7ffb1e04c 100644
>> --- a/drivers/tty/hvc/hvc_xen.c
>> +++ b/drivers/tty/hvc/hvc_xen.c
>> @@ -86,6 +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 */
>> +
>> +    if (WARN_ONCE((prod - cons) > sizeof(intf->out),
>> +              "Illegal ring page indices"))
>> +        return -EINVAL;
>> +
>>       BUG_ON((prod - cons) > sizeof(intf->out));
> 
> Why keep the BUG_ON() ?

Oh, failed to delete it. Thanks for noticing.


Juergen

[-- Attachment #1.1.2: OpenPGP_0xB0DE9DD628BF132F.asc --]
[-- Type: application/pgp-keys, Size: 3135 bytes --]

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 495 bytes --]