* [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX
@ 2017-10-05 3:45 Kees Cook
2017-10-05 7:49 ` Christophe LEROY
0 siblings, 1 reply; 5+ messages in thread
From: Kees Cook @ 2017-10-05 3:45 UTC (permalink / raw)
To: linux-kernel
Cc: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman,
linuxppc-dev
When available, CONFIG_KERNEL_RWX should be default-enabled.
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
--
2.7.4
--
Kees Cook
Pixel Security
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX
2017-10-05 3:45 [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX Kees Cook
@ 2017-10-05 7:49 ` Christophe LEROY
2017-10-05 17:30 ` Kees Cook
0 siblings, 1 reply; 5+ messages in thread
From: Christophe LEROY @ 2017-10-05 7:49 UTC (permalink / raw)
To: Kees Cook, linux-kernel; +Cc: Paul Mackerras, linuxppc-dev
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.
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
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX
2017-10-05 7:49 ` Christophe LEROY
@ 2017-10-05 17:30 ` Kees Cook
2017-10-05 18:57 ` christophe leroy
0 siblings, 1 reply; 5+ messages in thread
From: Kees Cook @ 2017-10-05 17:30 UTC (permalink / raw)
To: Christophe LEROY; +Cc: LKML, Paul Mackerras, linuxppc-dev@lists.ozlabs.org
On Thu, Oct 5, 2017 at 12:49 AM, Christophe LEROY
<christophe.leroy@c-s.fr> wrote:
>
>
> Le 05/10/2017 =C3=A0 05:45, Kees Cook a =C3=A9crit :
>>
>> When available, CONFIG_KERNEL_RWX should be default-enabled.
>
>
> On PPC32, this option implies deactivating BATs and/or LTLB mapping of th=
e
> 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
-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
>>
>
--=20
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX
2017-10-05 17:30 ` Kees Cook
@ 2017-10-05 18:57 ` christophe leroy
2017-10-05 18:58 ` Kees Cook
0 siblings, 1 reply; 5+ messages in thread
From: christophe leroy @ 2017-10-05 18:57 UTC (permalink / raw)
To: Kees Cook; +Cc: LKML, Paul Mackerras, linuxppc-dev@lists.ozlabs.org
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
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX
2017-10-05 18:57 ` christophe leroy
@ 2017-10-05 18:58 ` Kees Cook
0 siblings, 0 replies; 5+ messages in thread
From: Kees Cook @ 2017-10-05 18:58 UTC (permalink / raw)
To: christophe leroy; +Cc: LKML, Paul Mackerras, linuxppc-dev@lists.ozlabs.org
On Thu, Oct 5, 2017 at 11:57 AM, christophe leroy
<christophe.leroy@c-s.fr> wrote:
>
>
> Le 05/10/2017 =C3=A0 19:30, Kees Cook a =C3=A9crit :
>>
>> On Thu, Oct 5, 2017 at 12:49 AM, Christophe LEROY
>> <christophe.leroy@c-s.fr> wrote:
>>>
>>>
>>>
>>> Le 05/10/2017 =C3=A0 05:45, Kees Cook a =C3=A9crit :
>>>>
>>>>
>>>> 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 degradatio=
n.
>>>
>>> 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 ?
Oops, yes! :)
-Kees
--=20
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-10-05 3:45 [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX Kees Cook
2017-10-05 7:49 ` Christophe LEROY
2017-10-05 17:30 ` Kees Cook
2017-10-05 18:57 ` christophe leroy
2017-10-05 18:58 ` Kees Cook
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