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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: Introduce execute-only page access permissions
Date: Fri, 2 May 2014 18:00:28 +0100	[thread overview]
Message-ID: <20140502170027.GE20642@arm.com> (raw)
In-Reply-To: <1399045792-5490-1-git-send-email-catalin.marinas@arm.com>

On Fri, May 02, 2014 at 04:49:52PM +0100, Catalin Marinas wrote:
> The ARMv8 architecture allows execute-only user permissions by clearing
> the PTE_UXN and PTE_USER bits. The kernel, however, can still access
> such page.
> 
> This patch changes the arm64 __P100 and __S100 protection_map[] macros
> to the new __PAGE_EXECONLY attributes. A side effect is that
> pte_valid_user() no longer triggers for __PAGE_EXECONLY since PTE_USER
> isn't set. To work around this, the check is done on the PTE_NG bit via
> the pte_valid_ng() macro. VM_READ is also checked now for page faults.

How does this interact with things like ptrace and pipes? Can I get the
kernel to read my text for me?

Also: do we really want to differ from x86 here?

Will

  reply	other threads:[~2014-05-02 17:00 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-02 15:49 [PATCH] arm64: Introduce execute-only page access permissions Catalin Marinas
2014-05-02 17:00 ` Will Deacon [this message]
2014-05-02 17:13   ` Catalin Marinas
2014-05-02 18:07     ` Will Deacon
2014-05-06 14:14       ` Catalin Marinas
  -- strict thread matches above, loose matches on Subject: below --
2016-08-11 17:44 Catalin Marinas
2016-08-11 17:44 ` Catalin Marinas
2016-08-11 17:44 ` Catalin Marinas
2016-08-12 18:23 ` Kees Cook
2016-08-12 18:23   ` Kees Cook
2016-08-12 18:23   ` Kees Cook
2016-08-15 10:47   ` Catalin Marinas
2016-08-15 10:47     ` Catalin Marinas
2016-08-15 10:47     ` Catalin Marinas
2016-08-15 17:45     ` Kees Cook
2016-08-15 17:45       ` Kees Cook
2016-08-15 17:45       ` Kees Cook
2016-08-16 16:18       ` Catalin Marinas
2016-08-16 16:18         ` Catalin Marinas
2016-08-16 16:18         ` Catalin Marinas
2016-08-25 10:30         ` Will Deacon
2016-08-25 10:30           ` Will Deacon
2016-08-25 10:30           ` Will Deacon
2016-08-25 15:24           ` Kees Cook
2016-08-25 15:24             ` Kees Cook
2016-08-25 15:24             ` Kees Cook

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