Re: [PATCH] nptl: Handle NULL abstime [BZ #26394]

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 17/08/2020 10:52, H.J. Lu wrote:
> On Mon, Aug 17, 2020 at 6:30 AM Lukasz Majewski <lukma@denx.de> wrote:
>>
>> Hi Andreas, H.J.,
>>
>>> On Aug 15 2020, H.J. Lu wrote:
>>>
>>>> From fa1f97680fca290a378c449f2b63682ee348fd2c Mon Sep 17 00:00:00
>>>> 2001 From: "H.J. Lu" <hjl.tools@gmail.com>
>>>> Date: Sat, 15 Aug 2020 11:06:35 -0700
>>>> Subject: [PATCH] nptl: Handle NULL abstime [BZ #26394]
>>>>
>>>> Since abstime passed to pthread_{clock|timed}join_np may be NULL,
>>
>> Could you point me to the exact reference that it is allowed (or
>> required) to pass NULL to this syscall?
>>
>> The one which I've found on the web:
>> https://linux.die.net/man/3/pthread_timedjoin_np
>>
>> doesn't mention about NULL pointer passed as the absolute time.
>> It says explicitly:
>> "The abstime argument is a structure of the following form, specifying
>> an absolute time measured since the Epoch"
>>
>>
>> As fair as I remember [1] glibc only handles the NULL pointer case when
>> it is explicitly written in the documentation/spec that NULL is passed
>> (like here: https://linux.die.net/man/2/timerfd_settime or here:
>> https://linux.die.net/man/2/utimensat).
>>
>> Link:
>> [1] -
>> https://sourceware.org/pipermail/libc-alpha/2019-November/108072.html
>>
> 
> sysdeps/pthread/tst-join14.c explicitly passes NULL:
> 
> static int
> do_test_clock (clockid_t clockid)
> {
>   pthread_t th = xpthread_create (NULL, tf, NULL);
> 
>   void *status;
>   int val = (clockid == CLOCK_USE_TIMEDJOIN)
>     ? pthread_timedjoin_np (th, &status, NULL)
>     : pthread_clockjoin_np (th, &status, clockid, NULL);
>   TEST_COMPARE (val, 0);
> 
>   if (status != (void *) 42l)
>     FAIL_EXIT1 ("return value %p, expected %p\n", status, (void *) 42l);
> 
>   return 0;
> }
> 

And it is a red-flag that you did not catch it running the testsuite.  Did you
check the patch with a full make check to certify there is no regressions?