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From: Andi Kleen <ak@linux.intel.com>
To: Elizabeth Figura <zfigura@codeweavers.com>
Cc: Arnd Bergmann <arnd@arndb.de>,  Greg Kroah-Hartman
 <gregkh@linuxfoundation.org>,  Jonathan Corbet <corbet@lwn.net>,  Shuah
 Khan <shuah@kernel.org>,  linux-kernel@vger.kernel.org,
  linux-api@vger.kernel.org,  wine-devel@winehq.org,  =?utf-8?Q?Andr=C3=A9?=
 Almeida
 <andrealmeid@igalia.com>,  Wolfram Sang <wsa@kernel.org>,  Arkadiusz Hiler
 <ahiler@codeweavers.com>,  Peter Zijlstra <peterz@infradead.org>,  Andy
 Lutomirski <luto@kernel.org>,  linux-doc@vger.kernel.org,
  linux-kselftest@vger.kernel.org
Subject: Re: [RFC PATCH v2 19/29] selftests: ntsync: Add some tests for
 NTSYNC_IOC_WAIT_ANY.
In-Reply-To: <20240131021356.10322-20-zfigura@codeweavers.com> (Elizabeth
	Figura's message of "Tue, 30 Jan 2024 20:13:46 -0600")
References: <20240131021356.10322-1-zfigura@codeweavers.com>
	<20240131021356.10322-20-zfigura@codeweavers.com>
Date: Wed, 31 Jan 2024 00:52:11 -0800
Message-ID: <878r45khqc.fsf@linux.intel.com>
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Elizabeth Figura <zfigura@codeweavers.com> writes:

> +TEST(test_wait_any)
> +{
> +	struct ntsync_mutex_args mutex_args = {0};
> +	struct ntsync_wait_args wait_args = {0};
> +	struct ntsync_sem_args sem_args = {0};
> +	__u32 owner, index, count;
> +	struct timespec timeout;
> +	int objs[2], fd, ret;
> +
> +	clock_gettime(CLOCK_MONOTONIC, &timeout);
> +
> +	fd = open("/dev/ntsync", O_CLOEXEC | O_RDONLY);
> +	ASSERT_LE(0, fd);
> +
> +	sem_args.count = 2;
> +	sem_args.max = 3;
> +	sem_args.sem = 0xdeadbeef;
> +	ret = ioctl(fd, NTSYNC_IOC_CREATE_SEM, &sem_args);
> +	EXPECT_EQ(0, ret);
> +	EXPECT_NE(0xdeadbeef, sem_args.sem);
> +
> +	mutex_args.owner = 0;
> +	mutex_args.count = 0;
> +	mutex_args.mutex = 0xdeadbeef;
> +	ret = ioctl(fd, NTSYNC_IOC_CREATE_MUTEX, &mutex_args);
> +	EXPECT_EQ(0, ret);
> +	EXPECT_NE(0xdeadbeef, mutex_args.mutex);

It seems your tests are missing test cases for exceeding any limits,
especially overflow/underflow cases. Since these are the most likely
for any security problems it would be good to have extra coverage here.
The fuzzers will hopefully hit it too.

Also some stress testing with multiple threads would be useful.

-Andi