From: Christophe LEROY <christophe.leroy@c-s.fr>
To: Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org
Cc: Paul Mackerras <paulus@samba.org>, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX
Date: Thu, 5 Oct 2017 09:49:06 +0200 [thread overview]
Message-ID: <6e6bf9ba-d66c-0bcc-358e-fed97b2ca5cd@c-s.fr> (raw)
In-Reply-To: <20171005034505.GA32157@beast>
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
>
next prev parent reply other threads:[~2017-10-05 7:49 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-05 3:45 [PATCH] powerpc: Default to enabling STRICT_KERNEL_RWX Kees Cook
2017-10-05 7:49 ` Christophe LEROY [this message]
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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