From 625b7b7f79c66626fb2b7687fc1a58309a57edd5 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 26 Jun 2019 21:45:07 -0700 Subject: [PATCH] x86/vsyscall: Change the default vsyscall mode to xonly The use case for full emulation over xonly is very esoteric, e.g. magic instrumentation tools. Change the default to the safer xonly mode. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Kees Cook Cc: Florian Weimer Cc: Jann Horn Cc: Borislav Petkov Cc: Kernel Hardening Cc: Peter Zijlstra Link: https://lkml.kernel.org/r/30539f8072d2376b9c9efcc07e6ed0d6bf20e882.1561610354.git.luto@kernel.org --- arch/x86/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0182d2c..32028ed 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 -- 2.7.4