1 files changed, 8 insertions, 10 deletions

diff --git a/arch/sh/kernel/io_trapped.c b/arch/sh/kernel/io_trapped.c
index 60c828a2b8a2..e803b14ef12e 100644
--- a/arch/sh/kernel/io_trapped.c
+++ b/arch/sh/kernel/io_trapped.c
@@ -102,7 +102,6 @@ int register_trapped_io(struct trapped_io *tiop)
 	pr_warn("unable to install trapped io filter\n");
 	return -1;
 }
-EXPORT_SYMBOL_GPL(register_trapped_io);
 
 void __iomem *match_trapped_io_handler(struct list_head *list,
 				       unsigned long offset,
@@ -131,11 +130,11 @@ void __iomem *match_trapped_io_handler(struct list_head *list,
 	spin_unlock_irqrestore(&trapped_lock, flags);
 	return NULL;
 }
-EXPORT_SYMBOL_GPL(match_trapped_io_handler);
 
 static struct trapped_io *lookup_tiop(unsigned long address)
 {
 	pgd_t *pgd_k;
+	p4d_t *p4d_k;
 	pud_t *pud_k;
 	pmd_t *pmd_k;
 	pte_t *pte_k;
@@ -145,7 +144,11 @@ static struct trapped_io *lookup_tiop(unsigned long address)
 	if (!pgd_present(*pgd_k))
 		return NULL;
 
-	pud_k = pud_offset(pgd_k, address);
+	p4d_k = p4d_offset(pgd_k, address);
+	if (!p4d_present(*p4d_k))
+		return NULL;
+
+	pud_k = pud_offset(p4d_k, address);
 	if (!pud_present(*pud_k))
 		return NULL;
 
@@ -267,7 +270,6 @@ static struct mem_access trapped_io_access = {
 
 int handle_trapped_io(struct pt_regs *regs, unsigned long address)
 {
-	mm_segment_t oldfs;
 	insn_size_t instruction;
 	int tmp;
 
@@ -278,16 +280,12 @@ int handle_trapped_io(struct pt_regs *regs, unsigned long address)
 
 	WARN_ON(user_mode(regs));
 
-	oldfs = get_fs();
-	set_fs(KERNEL_DS);
-	if (copy_from_user(&instruction, (void *)(regs->pc),
-			   sizeof(instruction))) {
-		set_fs(oldfs);
+	if (copy_from_kernel_nofault(&instruction, (void *)(regs->pc),
+				     sizeof(instruction))) {
 		return 0;
 	}
 
 	tmp = handle_unaligned_access(instruction, regs,
 				      &trapped_io_access, 1, address);
-	set_fs(oldfs);
 	return tmp == 0;
 }