From: Karim Manaouil <kmanaouil.dev@gmail.com>
To: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Dev Jain <dev.jain@arm.com>,
akpm@linux-foundation.org, david@redhat.com,
catalin.marinas@arm.com, will@kernel.org,
Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org,
surenb@google.com, mhocko@suse.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, suzuki.poulose@arm.com,
steven.price@arm.com, gshan@redhat.com,
linux-arm-kernel@lists.infradead.org,
yang@os.amperecomputing.com, ryan.roberts@arm.com,
anshuman.khandual@arm.com
Subject: Re: [PATCH v3 1/2] arm64: pageattr: Use pagewalk API to change memory permissions
Date: Sat, 14 Jun 2025 15:50:21 +0100 [thread overview]
Message-ID: <20250614145021.7yve56wcxf3dlvwg@ed.ac.uk> (raw)
In-Reply-To: <8077b321-8953-46aa-b06d-95c91823e6ce@lucifer.local>
On Fri, Jun 13, 2025 at 05:27:27PM +0100, Lorenzo Stoakes wrote:
> On Fri, Jun 13, 2025 at 07:13:51PM +0530, Dev Jain wrote:
> > + if (WARN_ON_ONCE((next - addr) != PGDIR_SIZE))
> > + return -EINVAL;
>
> I guess the point here is to assert that the searched range _entirely
> spans_ the folio that the higher order leaf page table entry describes.
>
> I'm guessing this is desired.
>
> But I'm not sure this should be a warning?
>
> What if you happen to walk a range that isn't aligned like this?
My understandging is that the caller must ensure that addr is
pud/pmd/pte-aligned. But, imho, since -EINVAL is returned, I don't think
the WARN_ON_ONCE() is needed.
--
~karim
next prev parent reply other threads:[~2025-06-14 14:50 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-13 13:43 [PATCH v3 0/2] Enable permission change on arm64 kernel block mappings Dev Jain
2025-06-13 13:43 ` [PATCH v3 1/2] arm64: pageattr: Use pagewalk API to change memory permissions Dev Jain
2025-06-13 16:27 ` Lorenzo Stoakes
2025-06-14 14:50 ` Karim Manaouil [this message]
2025-06-19 4:03 ` Dev Jain
2025-06-25 10:57 ` Ryan Roberts
2025-06-15 7:25 ` Mike Rapoport
2025-06-25 10:57 ` Ryan Roberts
2025-06-15 7:32 ` Mike Rapoport
2025-06-19 4:10 ` Dev Jain
2025-06-25 11:04 ` Ryan Roberts
2025-06-25 20:40 ` Yang Shi
2025-06-26 8:47 ` Ryan Roberts
2025-06-26 21:08 ` Yang Shi
2025-06-25 11:20 ` Ryan Roberts
2025-06-26 5:47 ` Dev Jain
2025-06-26 8:15 ` Ryan Roberts
2025-06-13 13:43 ` [PATCH v3 2/2] arm64: pageattr: Enable huge-vmalloc permission change Dev Jain
2025-06-25 11:08 ` Ryan Roberts
2025-06-25 11:16 ` Dev Jain
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