Re: [Qemu-devel] [Xen-devel] [XEN][RFC PATCH V2 11/17] xc: modify save/restore to support multiple device models

[Julien Grall <julien.grall@citrix.com>]

On 08/23/2012 02:27 PM, Ian Campbell wrote:
>
>> @@ -103,6 +103,9 @@ static ssize_t rdexact(xc_interface *xch, struct restore_ctx *ctx,
>>   #else
>>   #define RDEXACT read_exact
>>   #endif
>> +
>> +#define QEMUSIG_SIZE 21
>> +
>>   /*
>>   ** In the state file (or during transfer), all page-table pages are
>>   ** converted into a 'canonical' form where references to actual mfns
>> @@ -467,7 +522,7 @@ static int buffer_tail_hvm(xc_interface *xch, struct restore_ctx *ctx,
>>                              int vcpuextstate, uint32_t vcpuextstate_size)
>>   {
>>       uint8_t *tmp;
>> -    unsigned char qemusig[21];
>> +    unsigned char qemusig[QEMUSIG_SIZE + 1];
>>      
> An extra + 1 here?
>    
QEMUSIG_SIZE doesn't take into account the '\0'. So we need to add 1.
If an error occurred, without +1, the output log lost the last character.

> [...]
>    
>> -    qemusig[20] = '\0';
>> +    qemusig[QEMUSIG_SIZE] = '\0';
>>      
> This is one bigger than it used to be now.
>
> Perhaps this is an unrelated bug fix (I haven't check the real length of
> the sig), in which case please can you split it out and submit
> separately?
>    

#define QEMU_SIGNATURE "DeviceModelRecord0002"
Just checked, the length seems to be 21. I will send a patch with
this change.

-- 
Julien