1 files changed, 14 insertions, 9 deletions

diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index c9450982a155..106f83a5ea6d 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -24,6 +24,7 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
 {
 	unsigned long addr = (unsigned long)_addr;
 	pgd_t *pgd;
+	p4d_t *p4d;
 	pmd_t *pmd;
 	pte_t *pte;
 	pud_t *pud;
@@ -33,7 +34,11 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
 	if (unlikely(pgd_none(*pgd) || pgd_bad(*pgd)))
 		return 0;
 
-	pud = pud_offset(pgd, addr);
+	p4d = p4d_offset(pgd, addr);
+	if (unlikely(p4d_none(*p4d) || p4d_bad(*p4d)))
+		return 0;
+
+	pud = pud_offset(p4d, addr);
 	if (unlikely(pud_none(*pud) || pud_bad(*pud)))
 		return 0;
 
@@ -96,7 +101,7 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
 	atomic = faulthandler_disabled();
 
 	if (!atomic)
-		down_read(&current->mm->mmap_sem);
+		mmap_read_lock(current->mm);
 	while (n) {
 		pte_t *pte;
 		spinlock_t *ptl;
@@ -104,11 +109,11 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
 
 		while (!pin_page_for_write(to, &pte, &ptl)) {
 			if (!atomic)
-				up_read(&current->mm->mmap_sem);
+				mmap_read_unlock(current->mm);
 			if (__put_user(0, (char __user *)to))
 				goto out;
 			if (!atomic)
-				down_read(&current->mm->mmap_sem);
+				mmap_read_lock(current->mm);
 		}
 
 		tocopy = (~(unsigned long)to & ~PAGE_MASK) + 1;
@@ -128,7 +133,7 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
 			spin_unlock(ptl);
 	}
 	if (!atomic)
-		up_read(&current->mm->mmap_sem);
+		mmap_read_unlock(current->mm);
 
 out:
 	return n;
@@ -165,17 +170,17 @@ __clear_user_memset(void __user *addr, unsigned long n)
 		return 0;
 	}
 
-	down_read(&current->mm->mmap_sem);
+	mmap_read_lock(current->mm);
 	while (n) {
 		pte_t *pte;
 		spinlock_t *ptl;
 		int tocopy;
 
 		while (!pin_page_for_write(addr, &pte, &ptl)) {
-			up_read(&current->mm->mmap_sem);
+			mmap_read_unlock(current->mm);
 			if (__put_user(0, (char __user *)addr))
 				goto out;
-			down_read(&current->mm->mmap_sem);
+			mmap_read_lock(current->mm);
 		}
 
 		tocopy = (~(unsigned long)addr & ~PAGE_MASK) + 1;
@@ -193,7 +198,7 @@ __clear_user_memset(void __user *addr, unsigned long n)
 		else
 			spin_unlock(ptl);
 	}
-	up_read(&current->mm->mmap_sem);
+	mmap_read_unlock(current->mm);
 
 out:
 	return n;