[v2,6/8] x86/vsyscall: Change the default vsyscall mode to xonly
diff mbox series

Message ID 30539f8072d2376b9c9efcc07e6ed0d6bf20e882.1561610354.git.luto@kernel.org
State New
Headers show
Series
  • [v2,1/8] x86/vsyscall: Remove the vsyscall=native documentation
Related show

Commit Message

Andy Lutomirski June 27, 2019, 4:45 a.m. UTC
The use case for full emulation over xonly is very esoteric.  Let's
change the default to the safer xonly mode.

Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Kees Cook June 27, 2019, 5:30 p.m. UTC | #1
On Wed, Jun 26, 2019 at 09:45:07PM -0700, Andy Lutomirski wrote:
> The use case for full emulation over xonly is very esoteric.  Let's
> change the default to the safer xonly mode.
> 
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

I still think it'd be valuable to describe any known esoteric cases
here, but regardless:

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  arch/x86/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 0182d2c67590..32028edc1b0e 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2285,7 +2285,7 @@ config COMPAT_VDSO
>  choice
>  	prompt "vsyscall table for legacy applications"
>  	depends on X86_64
> -	default LEGACY_VSYSCALL_EMULATE
> +	default LEGACY_VSYSCALL_XONLY
>  	help
>  	  Legacy user code that does not know how to find the vDSO expects
>  	  to be able to issue three syscalls by calling fixed addresses in
> -- 
> 2.21.0
>

Patch
diff mbox series

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0182d2c67590..32028edc1b0e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2285,7 +2285,7 @@  config COMPAT_VDSO
 choice
 	prompt "vsyscall table for legacy applications"
 	depends on X86_64
-	default LEGACY_VSYSCALL_EMULATE
+	default LEGACY_VSYSCALL_XONLY
 	help
 	  Legacy user code that does not know how to find the vDSO expects
 	  to be able to issue three syscalls by calling fixed addresses in