| Date | Wed, 6 Dec 2017 17:01:22 +0100 | From | Borislav Petkov <> | Subject | Re: [patch 37/60] x86mm//kpti: Force entry through trampoline when KPTI active |
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On Mon, Dec 04, 2017 at 03:07:43PM +0100, Thomas Gleixner wrote: > From: Thomas Gleixner <tglx@linutronix.de> > > Force the entry through the trampoline only when KPTI is active. Otherwise > go through the normal entry code. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > > --- > 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 <bp@suse.de>
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
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