On Wed, Jul 20, 2022 at 10:57:01AM +0200, Alexander Potapenko wrote:
> > /*
> > @@ -491,6 +493,8 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
> > {
> > struct mm_struct *real_prev = this_cpu_read(cpu_tlbstate.loaded_mm);
> > u16 prev_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
> > + unsigned long prev_lam = tlbstate_lam_cr3_mask();
> Note: this variable is never used if CONFIG_DEBUG_VM is off.
Good point. I will add this:
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 4c93f87a8928..5e9ed9f55c36 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -558,6 +558,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
if (real_prev == next) {
VM_WARN_ON(this_cpu_read(cpu_tlbstate.ctxs[prev_asid].ctx_id) !=
next->context.ctx_id);
+ VM_WARN_ON(prev_lam != new_lam);
/*
* Even in lazy TLB mode, the CPU should stay set in the
--
Kirill A. Shutemov
