selftests: vDSO: fix compile error for vdso_test_getrandom

When building selftests/vDSO:
$ make -C tools/testing/selftests TARGETS=vDSO
I hit the following compilation error:

  vdso_test_getrandom.c:260:17: error: 'CLONE_NEWTIME' undeclared
  (first use in this function); did you mean 'CLONE_NEWIPC'?
    260 |  assert(unshare(CLONE_NEWTIME) == 0);
        |                 ^~~~~~~~~~~~~

CLONE_NEWTIME is defined in linux/sched.h, so fix this by including
<linux/sched.h>.

Fixes: 2aec90036dcd ("selftests: vDSO: ensure vgetrandom works in a time namespace")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
---
 tools/testing/selftests/vDSO/vdso_test_getrandom.c | 1 +
 1 file changed, 1 insertion(+)

On 2024/9/20 0:51, Shuah Khan wrote:

>> diff --git a/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>> b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>> index 72a1d9b43a84..84f2bbb2d5e0 100644
>> --- a/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>> +++ b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>> @@ -19,6 +19,7 @@
>>   #include <sys/ptrace.h>
>>   #include <sys/wait.h>
>>   #include <sys/types.h>
>> +#include <linux/sched.h>
>>   #include <linux/random.h>
>>   #include <linux/compiler.h>
>>   #include <linux/ptrace.h>
> 
> Do you see this error after installing headers? Installing headers is
> a dependency to be able to compile selftests.
> 

Yes, this error still exists after installing header files. Here are my steps
to reproduce:

make headers_install
make -C tools/testing/selftests TARGETS=vDSO

After applying the patch, the error no longer appears.

Best regards,
Yu

Le 20/09/2024 à 03:54, Yu Liao a écrit :
> [Vous ne recevez pas souvent de courriers de liaoyu15@huawei.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
> 
> On 2024/9/20 0:51, Shuah Khan wrote:
> 
>>> diff --git a/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>>> b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>>> index 72a1d9b43a84..84f2bbb2d5e0 100644
>>> --- a/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>>> +++ b/tools/testing/selftests/vDSO/vdso_test_getrandom.c
>>> @@ -19,6 +19,7 @@
>>>    #include <sys/ptrace.h>
>>>    #include <sys/wait.h>
>>>    #include <sys/types.h>
>>> +#include <linux/sched.h>

This not correct. According to man page of clone(2), CLONE_ macros are 
in <sched.h>, you should include <sched.h> instead.

See https://man7.org/linux/man-pages/man2/clone.2.html

By the way on my environment (gcc 12.2 + glibc 2.38), <sched.h> gets 
already indirectly included by <phread.h>, and at the end the 
CLONE_NEWTIME is in glibc headers in usr/include/bits/sched.h

>>>    #include <linux/random.h>
>>>    #include <linux/compiler.h>
>>>    #include <linux/ptrace.h>
>>
>> Do you see this error after installing headers? Installing headers is
>> a dependency to be able to compile selftests.
>>
> 
> Yes, this error still exists after installing header files. Here are my steps
> to reproduce:
> 
> make headers_install
> make -C tools/testing/selftests TARGETS=vDSO
> 
> After applying the patch, the error no longer appears.
> 
> Best regards,
> Yu