On Mon, Jun 10, 2019 at 01:25:31PM -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. Perhaps describe the esoteric cases here (and maybe in the Kconfig help text)? That should a user determine if they actually need it. (What would the failure under xonly look like for someone needing emulate?) -Kees > > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxxxx> > Cc: Kernel Hardening <kernel-hardening@xxxxxxxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> > --- > arch/x86/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 054033cc4b1b..e56f33e6b045 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -2280,7 +2280,7 @@ 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 > -- Kees Cook
