Re: [PATCH] stm class: correct masterID range in setting via sysfs

From: Chunyan Zhang
Date: Fri Apr 08 2016 - 08:40:17 EST


On Fri, Apr 8, 2016 at 7:53 PM, Alexander Shishkin
<alexander.shishkin@xxxxxxxxxxxxxxx> wrote:
> Chunyan Zhang <zhang.chunyan@xxxxxxxxxx> writes:
>
>> The type of masterID is defined as 'unsigned int', theoretically one
>> can set masterID with a number larger than 'INT_MAX' as long as
>> 'stm_data::sw_end' is larger than 'INT_MAX'.
>>
>> Also, 'stm_data::start' and 'stm_data::end' is initialized in respective
>> drivers which should be able to use any value less than 'UINT_MAX' for
>> their masterIDs, of course including those values larger than 'INT_MAX',
>> but the current policy is wrongly assuming that masterIDs would not be
>> larger than 'INT_MAX'. This patch just corrected that.
>>
>> Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
>> ---
>> drivers/hwtracing/stm/policy.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c
>> index 1db1896..ce3edfd 100644
>> --- a/drivers/hwtracing/stm/policy.c
>> +++ b/drivers/hwtracing/stm/policy.c
>> @@ -107,7 +107,7 @@ stp_policy_node_masters_store(struct config_item *item, const char *page,
>> goto unlock;
>>
>> /* must be within [sw_start..sw_end], which is an inclusive range */
>> - if (first > INT_MAX || last > INT_MAX || first > last ||
>> + if (first > UINT_MAX || last > UINT_MAX || first > last ||
>
> Of course, I wasn't paying attention, testing an unsigned integer for
> being greater than UINT_MAX doesn't really make sense.
>

Ah right, checking first/last > INT/UINT_MAX is not needed actually.

Thanks for double review,
Chunyan

> Regards,
> --
> Alex