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Message-ID: <c6a4c016-e889-422c-91aa-91568f6667f4@opensource.cirrus.com>
Date: Thu, 4 Jan 2024 11:52:28 +0000
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Subject: Re: [PATCH] kunit: Protect string comparisons against NULL
To: David Gow <davidgow@google.com>
CC: <brendan.higgins@linux.dev>, <rmoar@google.com>,
        <linux-kselftest@vger.kernel.org>, <kunit-dev@googlegroups.com>,
        <linux-kernel@vger.kernel.org>, <patches@opensource.cirrus.com>
References: <20231220155256.407974-1-rf@opensource.cirrus.com>
 <CABVgOSnoJEZOCdPBVqBKS=sEXeeq_6_+G4PPodY0HWJ3A7yA+A@mail.gmail.com>
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From: Richard Fitzgerald <rf@opensource.cirrus.com>
In-Reply-To: <CABVgOSnoJEZOCdPBVqBKS=sEXeeq_6_+G4PPodY0HWJ3A7yA+A@mail.gmail.com>
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On 22/12/23 08:39, David Gow wrote:
> On Wed, 20 Dec 2023 at 23:52, Richard Fitzgerald
> <rf@opensource.cirrus.com> wrote:
>>
>> Add NULL checks to KUNIT_BINARY_STR_ASSERTION() so that it will fail
>> cleanly if either pointer is NULL, instead of causing a NULL pointer
>> dereference in the strcmp().
>>
>> A test failure could be that a string is unexpectedly NULL. This could
>> be trapped by KUNIT_ASSERT_NOT_NULL() but that would terminate the test
>> at that point. It's preferable that the KUNIT_EXPECT_STR*() macros can
>> handle NULL pointers as a failure.
>>
>> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
>> ---
> 
> I think this is the right thing to do. There's possibly an argument
> that this should succeed if both are NULL, but I prefer it this way.
> 

Maybe an _OR_NULL() variant of the string test macros would be better to
be explicit that NULL is acceptable.

> Reviewed-by: David Gow <davidgow@google.com>
> 
> Cheers,
> -- David