* Thomas Gleixner <[email protected]> wrote:
> When PTI is disabled at boot time either because the CPU is not affected or > PTI has been disabled on the command line, the boot code still calls into > pti_finalize() which then unconditionally invokes: > > pti_clone_entry_text() > pti_clone_kernel_text() > > pti_clone_kernel_text() was called unconditionally before the 32bit support > was added and 32bit added the call to pti_clone_entry_text(). > > The call has no side effects as cloning the page tables into the available > second one, which was allocated for PTI does not create damage. But it does > not make sense either and in case that this functionality would be extended > later this might actually lead to hard to diagnose issue. s/issue/issues > Neither function should be called when PTI is runtime disabled. Make the > invocation conditional. > > Signed-off-by: Thomas Gleixner <[email protected]> > --- > arch/x86/mm/pti.c | 2 ++ > 1 file changed, 2 insertions(+) > > --- a/arch/x86/mm/pti.c > +++ b/arch/x86/mm/pti.c > @@ -668,6 +668,8 @@ void __init pti_init(void) > */ > void pti_finalize(void) > { > + if (!boot_cpu_has(X86_FEATURE_PTI)) > + return; > /* > * We need to clone everything (again) that maps parts of the > * kernel image. Acked-by: Ingo Molnar <[email protected]> Thanks, Ingo
