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From:   Anshuman Khandual <anshuman.khandual@arm.com>
Subject: Re: [RFC] mm/pgtable/debug: Add test validating architecture page
 table helpers
To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     linux-mm@kvack.org, Mark Rutland <mark.rutland@arm.com>,
        x86@kernel.org, Kees Cook <keescook@chromium.org>,
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Date:   Fri, 26 Jul 2019 09:58:56 +0530
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On 07/25/2019 10:37 PM, Catalin Marinas wrote:
> On Thu, Jul 25, 2019 at 12:25:23PM +0530, Anshuman Khandual wrote:
>> +#if !defined(__PAGETABLE_PMD_FOLDED) && !defined(__ARCH_HAS_4LEVEL_HACK)
>> +static void pud_clear_tests(void)
>> +{
>> +	pud_t pud;
>> +
>> +	pud_clear(&pud);
>> +	WARN_ON(!pud_none(pud));
>> +}
> 
> For the clear tests, I think you should initialise the local variable to
> something non-zero rather than rely on whatever was on the stack. In
> case it fails, you have a more deterministic behaviour.

Sure, it makes sense, will change.