lkml.org 
[lkml]   [2017]   [Oct]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX
From
Date


Le 05/10/2017 à 19:30, Kees Cook a écrit :
> On Thu, Oct 5, 2017 at 12:49 AM, Christophe LEROY
> <christophe.leroy@c-s.fr> wrote:
>>
>>
>> Le 05/10/2017 à 05:45, Kees Cook a écrit :
>>>
>>> When available, CONFIG_KERNEL_RWX should be default-enabled.
>>
>>
>> On PPC32, this option implies deactivating BATs and/or LTLB mapping of the
>> linear kernel address space, hence a significant performance degradation.
>>
>> So at least on PPC32, it should remain unselected by default.
>
> Alright, sounds fine to me. Would this be okay?
>
> + select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if !PPC64

You mean

select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if PPC64

Don't you ?

Christophe

>
> -Kees
>
>>
>> Christophe
>>
>>
>>>
>>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>> Cc: Paul Mackerras <paulus@samba.org>
>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>> Cc: linuxppc-dev@lists.ozlabs.org
>>> Signed-off-by: Kees Cook <keescook@chromium.org>
>>> ---
>>> arch/powerpc/Kconfig | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>> index 809c468edab1..9a549bbfc278 100644
>>> --- a/arch/powerpc/Kconfig
>>> +++ b/arch/powerpc/Kconfig
>>> @@ -178,6 +178,7 @@ config PPC
>>> select HAVE_ARCH_TRACEHOOK
>>> select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 ||
>>> PPC32) && !RELOCATABLE && !HIBERNATION)
>>> select ARCH_OPTIONAL_KERNEL_RWX if
>>> ARCH_HAS_STRICT_KERNEL_RWX
>>> + select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
>>> select HAVE_CBPF_JIT if !PPC64
>>> select HAVE_CONTEXT_TRACKING if PPC64
>>> select HAVE_DEBUG_KMEMLEAK
>>>
>>
>
>
>

---
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
https://www.avast.com/antivirus

\
 
 \ /
  Last update: 2017-10-05 20:58    [W:0.043 / U:7.428 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site