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From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Jason Gunthorpe <jgg@nvidia.com>,
	David Hildenbrand <david@redhat.com>,
	akpm@linux-foundation.org,
	Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org
Subject: get_user_pages() and EXEC_ONLY mapping.
Date: Fri, 10 Nov 2023 20:19:23 +0530	[thread overview]
Message-ID: <87bkc1oe8c.fsf@linux.ibm.com> (raw)


Hello,

Some architectures can now support EXEC_ONLY mappings and I am wondering
what get_user_pages() on those addresses should return. Earlier
PROT_EXEC implied PROT_READ and pte_access_permitted() returned true for
that. But arm64 does have this explicit comment that says

 /*
 * p??_access_permitted() is true for valid user mappings (PTE_USER
 * bit set, subject to the write permission check). For execute-only
 * mappings, like PROT_EXEC with EPAN (both PTE_USER and PTE_UXN bits
 * not set) must return false. PROT_NONE mappings do not have the
 * PTE_VALID bit set.
 */

Is that correct? We should be able to get struct page for PROT_EXEC
mappings?

-aneesh

             reply	other threads:[~2023-11-10 14:50 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-10 14:49 Aneesh Kumar K.V [this message]
2023-11-10 14:53 ` get_user_pages() and EXEC_ONLY mapping Jason Gunthorpe
2023-11-10 14:53   ` Jason Gunthorpe
2023-11-10 14:57   ` Aneesh Kumar K V
2023-11-10 15:06     ` Jason Gunthorpe
2023-11-10 15:06       ` Jason Gunthorpe
2023-11-10 17:17 ` Catalin Marinas
2023-11-10 17:17   ` Catalin Marinas

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