linux-kernel - Re: [PATCH v2 5/5] mm/mseal: rework mseal apply logic

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Message-ID: <f5b7067f-7755-4be7-a376-d28070744723@redhat.com>
Date: Wed, 16 Jul 2025 15:41:20 +0200
From: David Hildenbrand <david@...hat.com>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
 Andrew Morton <akpm@...ux-foundation.org>
Cc: "Liam R . Howlett" <Liam.Howlett@...cle.com>,
 Vlastimil Babka <vbabka@...e.cz>, Jann Horn <jannh@...gle.com>,
 Pedro Falcato <pfalcato@...e.de>, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org, Jeff Xu <jeffxu@...omium.org>
Subject: Re: [PATCH v2 5/5] mm/mseal: rework mseal apply logic

On 15.07.25 15:37, Lorenzo Stoakes wrote:
> The logic can be simplified - firstly by renaming the inconsistently named
> apply_mm_seal() to mseal_apply().
> 
> We then wrap mseal_fixup() into the main loop as the logic is simple enough
> to not require it, equally it isn't a hugely pleasant pattern in mprotect()
> etc. so it's not something we want to perpetuate.
> 
> We remove some redundant comments, and then avoid the entirely unnecessary
> and slightly bizarre invocation of vma_iter_end() on each loop - really
> what we want, given we have asserted there are no gaps in the range - is to
> handle start, end being offset into a VMAs. This is easily handled with
> MIN()/MAX().
> 
> There's no need to have an 'out' label block since on vma_modify_flags()
> error we abort anyway.
> 
> And by refactoring like this we avoid the rather horrid 'pass pointer to
> prev around' pattern used in mprotect() et al.
> 
> No functional change intended.
> 
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
> Reviewed-by: Pedro Falcato <pfalcato@...e.de>
> ---

Acked-by: David Hildenbrand <david@...hat.com>

-- 
Cheers,

David / dhildenb