Re: [PATCH 1/1] ipr: Fix invalid array indexing for HRRQ

[Brian King <brking@linux.vnet.ibm.com>]

On 06/25/2015 09:36 AM, Jiri Slaby wrote:
> On 06/25/2015, 03:44 PM, Brian King wrote:
>> Fixes another signed / unsigned array indexing bug in the ipr driver.
> 
> Could you be more specific? Specifically, I fail to see why you do +1
> twice now.

Regarding the extra +1, you are correct. Its not needed. Let me fix up the
commit comment and this and resend.

Thanks,

Brian


> 
>> --- linux/drivers/scsi/ipr.c~ipr_hrrq_index_fix	2015-06-23 11:43:18.151741523 -0500
>> +++ linux-bjking1/drivers/scsi/ipr.c	2015-06-23 11:43:18.157741435 -0500
>> @@ -1052,10 +1052,15 @@ static void ipr_send_blocking_cmd(struct
>>  
>>  static int ipr_get_hrrq_index(struct ipr_ioa_cfg *ioa_cfg)
>>  {
>> +	unsigned int hrrq;
>> +
>>  	if (ioa_cfg->hrrq_num == 1)
>> -		return 0;
>> -	else
>> -		return (atomic_add_return(1, &ioa_cfg->hrrq_index) % (ioa_cfg->hrrq_num - 1)) + 1;
>> +		hrrq = 0;
>> +	else {
>> +		hrrq = atomic_add_return(1, &ioa_cfg->hrrq_index);
>> +		hrrq = ((hrrq + 1) % (ioa_cfg->hrrq_num - 1)) + 1;
>> +	}
>> +	return hrrq;
> 
> thanks,
> 


-- 
Brian King
Power Linux I/O
IBM Linux Technology Center