This one is updated upon each context switch to reflect the crrent mm's pti_disable field.
Signed-off-by: Willy Tarreau <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Kees Cook <[email protected]> --- arch/x86/kernel/process_64.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 9516310..9bb5908 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -61,6 +61,10 @@ __visible DEFINE_PER_CPU(unsigned long, rsp_scratch); +#ifdef CONFIG_PAGE_TABLE_ISOLATION +__visible DEFINE_PER_CPU(unsigned char, pti_disable); +#endif + /* Prints also some state that isn't saved in the pt_regs */ void __show_regs(struct pt_regs *regs, int all) { @@ -473,6 +477,11 @@ void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp) task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) __switch_to_xtra(prev_p, next_p, tss); +#ifdef CONFIG_PAGE_TABLE_ISOLATION + this_cpu_write(pti_disable, + next_p->mm && next_p->mm->context.pti_disable); +#endif + #ifdef CONFIG_XEN_PV /* * On Xen PV, IOPL bits in pt_regs->flags have no effect, and -- 1.7.12.1
