On Mon, Dec 18, 2017 at 12:42:18PM +0100, Thomas Gleixner wrote:
> From: Andy Lutomirski <l...@kernel.org>
>
> If something goes wrong with pagetable setup, vsyscall=native will
> accidentally fall back to emulation. Make it warn and fail so that we
> notice.
>
> Signed-off-by: Andy Lutomirski <l...@kernel.org>
> Signed-off-by: Ingo Molnar <mi...@kernel.org>
> Signed-off-by: Thomas Gleixner <t...@linutronix.de>
> Cc: Borislav Petkov <b...@alien8.de>
> Cc: Brian Gerst <brge...@gmail.com>
> Cc: David Laight <david.lai...@aculab.com>
> Cc: Kees Cook <keesc...@chromium.org>
> Cc: Linus Torvalds <torva...@linux-foundation.org>
> Cc: Peter Zijlstra <pet...@infradead.org>
> ---
> arch/x86/entry/vsyscall/vsyscall_64.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> --- a/arch/x86/entry/vsyscall/vsyscall_64.c
> +++ b/arch/x86/entry/vsyscall/vsyscall_64.c
> @@ -138,6 +138,10 @@ bool emulate_vsyscall(struct pt_regs *re
>
> WARN_ON_ONCE(address != regs->ip);
>
> + /* This should be unreachable in NATIVE mode. */
> + if (WARN_ON(vsyscall_mode == NATIVE))
> + return false;
There's this nice warn_bad_vsyscall() thing. Why not use that?
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284
(AG Nürnberg)
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