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SubjectRe: [PATCH 01/30] x86, mm: do not set _PAGE_USER for init_mm page tables
On Wed, Nov 08, 2017 at 11:46:47AM -0800, Dave Hansen wrote:
>
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> init_mm is for kernel-exclusive use. If someone is allocating page
> tables for it, do not set _PAGE_USER on them.
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
> Cc: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
> Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
> Cc: Richard Fellner <richard.fellner@student.tugraz.at>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Kees Cook <keescook@google.com>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: x86@kernel.org
> ---
>
> b/arch/x86/include/asm/pgalloc.h | 33 ++++++++++++++++++++++++++++-----
> 1 file changed, 28 insertions(+), 5 deletions(-)
>
> diff -puN arch/x86/include/asm/pgalloc.h~kaiser-prep-clear-_PAGE_USER-for-init_mm arch/x86/include/asm/pgalloc.h
> --- a/arch/x86/include/asm/pgalloc.h~kaiser-prep-clear-_PAGE_USER-for-init_mm 2017-11-08 10:45:25.928681403 -0800
> +++ b/arch/x86/include/asm/pgalloc.h 2017-11-08 10:45:25.931681403 -0800
> @@ -61,20 +61,37 @@ static inline void __pte_free_tlb(struct
> ___pte_free_tlb(tlb, pte);
> }
>
> +/*
> + * init_mm is for kernel-exclusive use. Any page tables that
> + * are seteup for it should not be usable by userspace.

s/seteup/setup/

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

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