diff options
Diffstat (limited to 'arch/x86/mm/tlb.c')
| -rw-r--r-- | arch/x86/mm/tlb.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index dbbcfd59726a..1ab3821f9e26 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -121,8 +121,28 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, * hypothetical buggy code that directly switches to swapper_pg_dir * without going through leave_mm() / switch_mm_irqs_off() or that * does something like write_cr3(read_cr3_pa()). + * + * Only do this check if CONFIG_DEBUG_VM=y because __read_cr3() + * isn't free. */ - VM_BUG_ON(__read_cr3() != (__sme_pa(real_prev->pgd) | prev_asid)); +#ifdef CONFIG_DEBUG_VM + if (WARN_ON_ONCE(__read_cr3() != + (__sme_pa(real_prev->pgd) | prev_asid))) { + /* + * If we were to BUG here, we'd be very likely to kill + * the system so hard that we don't see the call trace. + * Try to recover instead by ignoring the error and doing + * a global flush to minimize the chance of corruption. + * + * (This is far from being a fully correct recovery. + * Architecturally, the CPU could prefetch something + * back into an incorrect ASID slot and leave it there + * to cause trouble down the road. It's better than + * nothing, though.) + */ + __flush_tlb_all(); + } +#endif if (real_prev == next) { VM_BUG_ON(this_cpu_read(cpu_tlbstate.ctxs[prev_asid].ctx_id) != @@ -241,7 +261,7 @@ void initialize_tlbstate_and_flush(void) * doesn't work like other CR4 bits because it can only be set from * long mode.) */ - WARN_ON(boot_cpu_has(X86_CR4_PCIDE) && + WARN_ON(boot_cpu_has(X86_FEATURE_PCID) && !(cr4_read_shadow() & X86_CR4_PCIDE)); /* Force ASID 0 and force a TLB flush. */ |