1 files changed, 37 insertions, 38 deletions

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 7062b84dd467..7196ca7048be 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -139,7 +139,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode,
 		       log_lvl, d3, d6, d7);
 	}
 
-	if (cpu_feature_enabled(X86_FEATURE_OSPKE))
+	if (cr4 & X86_CR4_PKE)
 		printk("%sPKRU: %08x\n", log_lvl, read_pkru());
 }
 
@@ -614,7 +614,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	int cpu = smp_processor_id();
 
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_DEBUG_ENTRY) &&
-		     this_cpu_read(pcpu_hot.hardirq_stack_inuse));
+		     this_cpu_read(hardirq_stack_inuse));
 
 	if (!test_tsk_thread_flag(prev_p, TIF_NEED_FPU_LOAD))
 		switch_fpu_prepare(prev_p, cpu);
@@ -668,8 +668,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	/*
 	 * Switch the PDA and FPU contexts.
 	 */
-	raw_cpu_write(pcpu_hot.current_task, next_p);
-	raw_cpu_write(pcpu_hot.top_of_stack, task_top_of_stack(next_p));
+	raw_cpu_write(current_task, next_p);
+	raw_cpu_write(cpu_current_top_of_stack, task_top_of_stack(next_p));
 
 	switch_fpu_finish(next_p);
 
@@ -798,6 +798,32 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr)
 
 #define LAM_U57_BITS 6
 
+static void enable_lam_func(void *__mm)
+{
+	struct mm_struct *mm = __mm;
+	unsigned long lam;
+
+	if (this_cpu_read(cpu_tlbstate.loaded_mm) == mm) {
+		lam = mm_lam_cr3_mask(mm);
+		write_cr3(__read_cr3() | lam);
+		cpu_tlbstate_update_lam(lam, mm_untag_mask(mm));
+	}
+}
+
+static void mm_enable_lam(struct mm_struct *mm)
+{
+	mm->context.lam_cr3_mask = X86_CR3_LAM_U57;
+	mm->context.untag_mask =  ~GENMASK(62, 57);
+
+	/*
+	 * Even though the process must still be single-threaded at this
+	 * point, kernel threads may be using the mm.  IPI those kernel
+	 * threads if they exist.
+	 */
+	on_each_cpu_mask(mm_cpumask(mm), enable_lam_func, mm, true);
+	set_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags);
+}
+
 static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits)
 {
 	if (!cpu_feature_enabled(X86_FEATURE_LAM))
@@ -814,25 +840,21 @@ static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits)
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
+	/*
+	 * MM_CONTEXT_LOCK_LAM is set on clone.  Prevent LAM from
+	 * being enabled unless the process is single threaded:
+	 */
 	if (test_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags)) {
 		mmap_write_unlock(mm);
 		return -EBUSY;
 	}
 
-	if (!nr_bits) {
-		mmap_write_unlock(mm);
-		return -EINVAL;
-	} else if (nr_bits <= LAM_U57_BITS) {
-		mm->context.lam_cr3_mask = X86_CR3_LAM_U57;
-		mm->context.untag_mask =  ~GENMASK(62, 57);
-	} else {
+	if (!nr_bits || nr_bits > LAM_U57_BITS) {
 		mmap_write_unlock(mm);
 		return -EINVAL;
 	}
 
-	write_cr3(__read_cr3() | mm->context.lam_cr3_mask);
-	set_tlbstate_lam_mode(mm);
-	set_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags);
+	mm_enable_lam(mm);
 
 	mmap_write_unlock(mm);
 
@@ -920,7 +942,7 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
 	case ARCH_MAP_VDSO_X32:
 		return prctl_map_vdso(&vdso_image_x32, arg2);
 # endif
-# if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
+# ifdef CONFIG_IA32_EMULATION
 	case ARCH_MAP_VDSO_32:
 		return prctl_map_vdso(&vdso_image_32, arg2);
 # endif
@@ -957,26 +979,3 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
 
 	return ret;
 }
-
-SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
-{
-	long ret;
-
-	ret = do_arch_prctl_64(current, option, arg2);
-	if (ret == -EINVAL)
-		ret = do_arch_prctl_common(option, arg2);
-
-	return ret;
-}
-
-#ifdef CONFIG_IA32_EMULATION
-COMPAT_SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
-{
-	return do_arch_prctl_common(option, arg2);
-}
-#endif
-
-unsigned long KSTK_ESP(struct task_struct *task)
-{
-	return task_pt_regs(task)->sp;
-}