On Mon, Dec 04, 2017 at 03:07:43PM +0100, Thomas Gleixner wrote: > From: Thomas Gleixner <[email protected]> > > Force the entry through the trampoline only when KPTI is active. Otherwise > go through the normal entry code. > > Signed-off-by: Thomas Gleixner <[email protected]> > > --- > arch/x86/kernel/cpu/common.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1458,7 +1458,10 @@ void syscall_init(void) > (entry_SYSCALL_64_trampoline - _entry_trampoline); > > wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS); > - wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline); > + if (static_cpu_has_bug(X86_BUG_CPU_SECURE_MODE_KPTI)) > + wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline); > + else > + wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); > > #ifdef CONFIG_IA32_EMULATION > wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat);
Just a nitpick: Subject: x86/mm/kpti:... Otherwise, Reviewed-by: Borislav Petkov <[email protected]> -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
