Re: [PATCH v8 2/9] stdlib: Add arc4random tests

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

On 12/07/22 06:20, Florian Weimer wrote:
> * Adhemerval Zanella:
> 
>> The basic tst-arc4random-chacha20.c checks if the output of ChaCha20
>> implementation matches the reference test vectors from RFC8439.
>>
>> The tst-arc4random-fork.c check if subprocesses generate distinct
>> streams of randomness (if fork handling is done correctly).
>>
>> The tst-arc4random-stats.c is a statistical test to the randomness of
>> arc4random, arc4random_buf, and arc4random_uniform.
>>
>> The tst-arc4random-thread.c check if threads generate distinct streams
>> of randomness (if function are thread-safe).
> 
> 
> Maybe mention in the commit message that the tests are based on a
> previous implementation, so the locking and race detection stuff is not
> necessarily relevant with the per-thread state?
> 
>> --- /dev/null
>> +++ b/stdlib/tst-arc4random-chacha20.c
>> @@ -0,0 +1,167 @@
> 
>> +#include <arc4random.h>
>> +#include <support/check.h>
>> +#include <sys/cdefs.h>
>> +
>> +/* The test does not define CHACHA20_XOR_FINAL to mimic what arc4random
>> +   actual does. */
> 
> Missing space after .

Ack.

> 
>> diff --git a/stdlib/tst-arc4random-fork.c b/stdlib/tst-arc4random-fork.c
>> new file mode 100644
>> index 0000000000..a7f7fee671
>> --- /dev/null
>> +++ b/stdlib/tst-arc4random-fork.c
>> @@ -0,0 +1,198 @@
>> +/* Test that subprocesses generate distinct streams of randomness.
>> +   Copyright (C) 2022 Free Software Foundation, Inc.
>> +   This file is part of the GNU C Library.
>> +
>> +   The GNU C Library is free software; you can redistribute it and/or
>> +   modify it under the terms of the GNU Lesser General Public
>> +   License as published by the Free Software Foundation; either
>> +   version 2.1 of the License, or (at your option) any later version.
>> +
>> +   The GNU C Library is distributed in the hope that it will be useful,
>> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> +   Lesser General Public License for more details.
>> +
>> +   You should have received a copy of the GNU Lesser General Public
>> +   License along with the GNU C Library; if not, see
>> +   <http://www.gnu.org/licenses/>.  */
> 
> http:// instead of https://.  (There are more occurrences.)

Ack.

> 
>> +/* Collect random data from subprocesses and check that all the
>> +   results are unique.  */
>> +
>> +#include <array_length.h>
>> +#include <stdlib.h>
>> +#include <stdio.h>
>> +#include <string.h>
>> +#include <support/check.h>
>> +#include <support/support.h>
>> +#include <support/xthread.h>
>> +#include <support/xunistd.h>
>> +#include <unistd.h>
>> +
>> +/* Perform multiple runs.  The subsequent runs start with an
>> +   already-initialized random number generator.  (The number 1500 was
>> +   seen to reproduce failures reliable in case of a race condition in
>> +   the fork detection code.)  */
>> +enum { runs = 1500 };
> 
> Comment is outdated, there is no fork detection code anymore.

Ok, I removed the fork-detection part.

> 
> 
>> diff --git a/stdlib/tst-arc4random-thread.c b/stdlib/tst-arc4random-thread.c
>> new file mode 100644
>> index 0000000000..935cdcaf12
>> --- /dev/null
>> +++ b/stdlib/tst-arc4random-thread.c
>> @@ -0,0 +1,341 @@
>> +/* Test that threads generate distinct streams of randomness.
>> +   Copyright (C) 2018 Free Software Foundation, Inc.
> 
> Should be 2022.
> 

Ack.

> Thanks,
> Florian
>