[PATCH] kselftest: vDSO: Fix accumulation of uninitialized ret when CLOCK_REALTIME is undefined

[PATCH] kselftest: vDSO: Fix accumulation of uninitialized ret when CLOCK_REALTIME is undefined

[Colin Ian King]

In the unlikely case that CLOCK_REALTIME is not defined, variable ret is
not initialized and further accumulation of return values to ret can leave
ret in an undefined state. Fix this by initialized ret to zero and changing
the assignment of ret to an accumulation for the CLOCK_REALTIME case.

Fixes: 03f55c7952c9 ("kselftest: Extend vDSO selftest to clock_getres")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
---
 tools/testing/selftests/vDSO/vdso_test_clock_getres.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vDSO/vdso_test_clock_getres.c b/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
index 15dcee16ff72..38d46a8bf7cb 100644
--- a/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
+++ b/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
@@ -84,12 +84,12 @@ static inline int vdso_test_clock(unsigned int clock_id)
 
 int main(int argc, char **argv)
 {
-	int ret;
+	int ret = 0;
 
 #if _POSIX_TIMERS > 0
 
 #ifdef CLOCK_REALTIME
-	ret = vdso_test_clock(CLOCK_REALTIME);
+	ret += vdso_test_clock(CLOCK_REALTIME);
 #endif
 
 #ifdef CLOCK_BOOTTIME
-- 
2.30.2

Re: [PATCH] kselftest: vDSO: Fix accumulation of uninitialized ret when CLOCK_REALTIME is undefined

[Vincenzo Frascino]

Hi Colin,

On 4/17/23 11:47, Colin Ian King wrote:
> In the unlikely case that CLOCK_REALTIME is not defined, variable ret is
> not initialized and further accumulation of return values to ret can leave
> ret in an undefined state. Fix this by initialized ret to zero and changing
> the assignment of ret to an accumulation for the CLOCK_REALTIME case.
> 

I was wondering how did you find this.

Apart that:

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> Fixes: 03f55c7952c9 ("kselftest: Extend vDSO selftest to clock_getres")
> Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
> ---
>  tools/testing/selftests/vDSO/vdso_test_clock_getres.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/vDSO/vdso_test_clock_getres.c b/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
> index 15dcee16ff72..38d46a8bf7cb 100644
> --- a/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
> +++ b/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
> @@ -84,12 +84,12 @@ static inline int vdso_test_clock(unsigned int clock_id)
>  
>  int main(int argc, char **argv)
>  {
> -	int ret;
> +	int ret = 0;
>  
>  #if _POSIX_TIMERS > 0
>  
>  #ifdef CLOCK_REALTIME
> -	ret = vdso_test_clock(CLOCK_REALTIME);
> +	ret += vdso_test_clock(CLOCK_REALTIME);
>  #endif
>  
>  #ifdef CLOCK_BOOTTIME

-- 
Regards,
Vincenzo

Re: [PATCH] kselftest: vDSO: Fix accumulation of uninitialized ret when CLOCK_REALTIME is undefined

[Colin King (gmail)]

On 18/04/2023 11:10, Vincenzo Frascino wrote:
> Hi Colin,
> 
> On 4/17/23 11:47, Colin Ian King wrote:
>> In the unlikely case that CLOCK_REALTIME is not defined, variable ret is
>> not initialized and further accumulation of return values to ret can leave
>> ret in an undefined state. Fix this by initialized ret to zero and changing
>> the assignment of ret to an accumulation for the CLOCK_REALTIME case.
>>
> 
> I was wondering how did you find this.

I used cppcheck --force --enable=all, this examines the #if defined() paths.

> 
> Apart that:
> 
> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> 
>> Fixes: 03f55c7952c9 ("kselftest: Extend vDSO selftest to clock_getres")
>> Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
>> ---
>>   tools/testing/selftests/vDSO/vdso_test_clock_getres.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/testing/selftests/vDSO/vdso_test_clock_getres.c b/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
>> index 15dcee16ff72..38d46a8bf7cb 100644
>> --- a/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
>> +++ b/tools/testing/selftests/vDSO/vdso_test_clock_getres.c
>> @@ -84,12 +84,12 @@ static inline int vdso_test_clock(unsigned int clock_id)
>>   
>>   int main(int argc, char **argv)
>>   {
>> -	int ret;
>> +	int ret = 0;
>>   
>>   #if _POSIX_TIMERS > 0
>>   
>>   #ifdef CLOCK_REALTIME
>> -	ret = vdso_test_clock(CLOCK_REALTIME);
>> +	ret += vdso_test_clock(CLOCK_REALTIME);
>>   #endif
>>   
>>   #ifdef CLOCK_BOOTTIME
> 

Re: [PATCH] kselftest: vDSO: Fix accumulation of uninitialized ret when CLOCK_REALTIME is undefined

[Shuah Khan]

On 4/18/23 04:14, Colin King (gmail) wrote:
> On 18/04/2023 11:10, Vincenzo Frascino wrote:
>> Hi Colin,
>>
>> On 4/17/23 11:47, Colin Ian King wrote:
>>> In the unlikely case that CLOCK_REALTIME is not defined, variable ret is
>>> not initialized and further accumulation of return values to ret can leave
>>> ret in an undefined state. Fix this by initialized ret to zero and changing
>>> the assignment of ret to an accumulation for the CLOCK_REALTIME case.
>>>
>>
>> I was wondering how did you find this.
> 
> I used cppcheck --force --enable=all, this examines the #if defined() paths.
> 
>>
>> Apart that:
>>
>> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
>>

Applied to linux-kselftest next

thanks,
-- Shuah