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Diffstat (limited to 'arch/x86/include/asm/mmu_context.h')
-rw-r--r--arch/x86/include/asm/mmu_context.h41
1 files changed, 30 insertions, 11 deletions
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 7ae318c340d9..6699fc441644 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_MMU_CONTEXT_H
#define _ASM_X86_MMU_CONTEXT_H
@@ -126,13 +127,7 @@ static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next)
DEBUG_LOCKS_WARN_ON(preemptible());
}
-static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
-{
- int cpu = smp_processor_id();
-
- if (cpumask_test_cpu(cpu, mm_cpumask(mm)))
- cpumask_clear_cpu(cpu, mm_cpumask(mm));
-}
+void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk);
static inline int init_new_context(struct task_struct *tsk,
struct mm_struct *mm)
@@ -286,6 +281,32 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
return __pkru_allows_pkey(vma_pkey(vma), write);
}
+/*
+ * If PCID is on, ASID-aware code paths put the ASID+1 into the PCID
+ * bits. This serves two purposes. It prevents a nasty situation in
+ * which PCID-unaware code saves CR3, loads some other value (with PCID
+ * == 0), and then restores CR3, thus corrupting the TLB for ASID 0 if
+ * the saved ASID was nonzero. It also means that any bugs involving
+ * loading a PCID-enabled CR3 with CR4.PCIDE off will trigger
+ * deterministically.
+ */
+
+static inline unsigned long build_cr3(struct mm_struct *mm, u16 asid)
+{
+ if (static_cpu_has(X86_FEATURE_PCID)) {
+ VM_WARN_ON_ONCE(asid > 4094);
+ return __sme_pa(mm->pgd) | (asid + 1);
+ } else {
+ VM_WARN_ON_ONCE(asid != 0);
+ return __sme_pa(mm->pgd);
+ }
+}
+
+static inline unsigned long build_cr3_noflush(struct mm_struct *mm, u16 asid)
+{
+ VM_WARN_ON_ONCE(asid > 4094);
+ return __sme_pa(mm->pgd) | (asid + 1) | CR3_NOFLUSH;
+}
/*
* This can be used from process context to figure out what the value of
@@ -296,10 +317,8 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
*/
static inline unsigned long __get_current_cr3_fast(void)
{
- unsigned long cr3 = __pa(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd);
-
- if (static_cpu_has(X86_FEATURE_PCID))
- cr3 |= this_cpu_read(cpu_tlbstate.loaded_mm_asid);
+ unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm),
+ this_cpu_read(cpu_tlbstate.loaded_mm_asid));
/* For now, be very restrictive about when this can be called. */
VM_WARN_ON(in_nmi() || preemptible());