From: james.morse@arm•com (James Morse)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4] arm64: kernel: Add support for Privileged Access Never
Date: Fri, 24 Jul 2015 16:14:54 +0100 [thread overview]
Message-ID: <55B2566E.2090905@arm.com> (raw)
In-Reply-To: <20150723130752.GC445@arm.com>
On 23/07/15 14:07, Will Deacon wrote:
> Hi James,
>
> First off, thanks for rebasing this patch.
>
> On Wed, Jul 22, 2015 at 07:05:54PM +0100, James Morse wrote:
>> 'Privileged Access Never' is a new arm8.1 feature which prevents
>> privileged code from accessing any virtual address where read or write
>> access is also permitted at EL0.
>>
>> This patch enables the PAN feature on all CPUs, and modifies {get,put}_user
>> helpers temporarily to permit access.
>>
>> This will catch kernel bugs where user memory is accessed directly.
>> 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN.
>>
>> Signed-off-by: James Morse <james.morse@arm•com>
>> Cc: Catalin Marinas <catalin.marinas@arm•com>
>> Cc: Will Deacon <will.deacon@arm•com>
>> ---
>> This version is rebased against the arm64 'devel' branch, somewhere
>> after Suzuki's "arm64: Generalise msr_s/mrs_s operations" patch.
>
> Now, having spoken with Catalin, we reckon that it's probably best to
> bite the bullet and add the enable parameter to the conditional alternative
> asm macros anyway; it's still fairly early days for 4.3 so we've got time
> to get this right.
>
> In that light, I've got the following diff against this patch (see below)
> and then another patch on top of that adding the extra parameters.
>
> Could you take a look please? Sorry for messing you about.
Fine by me ...
If you're able to merge it all together, please do. Otherwise I will try to
find time to send a v5.
James
next prev parent reply other threads:[~2015-07-24 15:14 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-21 12:23 [PATCH v3 0/6] arm64: kernel: Add support for Privileged Access Never James Morse
2015-07-21 12:23 ` [PATCH v3 1/6] arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extension James Morse
2015-07-21 12:32 ` Catalin Marinas
2015-07-21 12:23 ` [PATCH v3 2/6] arm64: kernel: preparatory: Move config_sctlr_el1 James Morse
2015-07-21 12:23 ` [PATCH v3 3/6] arm64: kernel: Add cpufeature 'enable' callback James Morse
2015-07-21 12:23 ` [PATCH v3 4/6] arm64: kernel: Add min_field_value and use '>=' for feature detection James Morse
2015-07-21 12:33 ` Catalin Marinas
2015-07-21 12:23 ` [PATCH v3 5/6] arm64: kernel: Add optional CONFIG_ parameter to ALTERNATIVE() James Morse
2015-07-21 12:23 ` [PATCH v3 6/6] arm64: kernel: Add support for Privileged Access Never James Morse
2015-07-21 12:38 ` Catalin Marinas
2015-07-22 17:01 ` Will Deacon
2015-07-22 18:04 ` James Morse
2015-07-22 18:14 ` Will Deacon
2015-07-23 7:58 ` James Morse
2015-07-22 18:05 ` [PATCH v4] " James Morse
2015-07-23 13:07 ` Will Deacon
2015-07-24 15:14 ` James Morse [this message]
2015-07-24 16:56 ` Will Deacon
2015-07-23 12:00 ` [PATCH v3 6/6] " Will Deacon
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