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

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

[Chunyan Zhang]

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@linaro.org>
---
 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 ||
 	    first < stm->data->sw_start ||
 	    last > stm->data->sw_end) {
 		ret = -ERANGE;
-- 
1.9.1

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

[Alexander Shishkin]

Chunyan Zhang <zhang.chunyan@linaro.org> 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@linaro.org>

Good catch, thanks!

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

[Alexander Shishkin]

Chunyan Zhang <zhang.chunyan@linaro.org> 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@linaro.org>
> ---
>  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.

Regards,
--
Alex

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

[Chunyan Zhang]

On Fri, Apr 8, 2016 at 7:53 PM, Alexander Shishkin
<alexander.shishkin@linux.intel.com> wrote:
> Chunyan Zhang <zhang.chunyan@linaro.org> 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@linaro.org>
>> ---
>>  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