diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c
index 19e4db582fb69a723dd5c4e9688103a04050da6f..ba93c4e6a2319f974c82e6094f1a38b04ccb6d97 100644
--- a/arch/x86/kernel/shstk.c
+++ b/arch/x86/kernel/shstk.c
@@ -18,6 +18,7 @@
 #include <linux/sizes.h>
 #include <linux/user.h>
 #include <linux/syscalls.h>
+#include <linux/highmem.h>
 #include <asm/msr.h>
 #include <asm/fpu/xstate.h>
 #include <asm/fpu/types.h>
@@ -262,11 +263,29 @@ static int put_shstk_data(u64 __user *addr, u64 data)
 	return 0;
 }
 
+/* Copy from aligned address in userspace without risk of page fault. */
+static int shstk_copy_user_gup(unsigned long *ldata, unsigned long __user *addr)
+{
+	struct page *page;
+	void *kaddr;
+
+	mmap_assert_locked(current->mm);
+	if (get_user_pages((unsigned long)addr, 1, 0, &page) != 1)
+		return -EFAULT;
+
+	kaddr = kmap_local_page(page);
+	*ldata = *(unsigned long *)(kaddr + offset_in_page(addr));
+	kunmap_local(kaddr);
+	put_page(page);
+
+	return 0;
+}
+
 static int get_shstk_data(unsigned long *data, unsigned long __user *addr)
 {
 	unsigned long ldata;
 
-	if (unlikely(get_user(ldata, addr)))
+	if (shstk_copy_user_gup(&ldata, addr))
 		return -EFAULT;
 
 	if (!(ldata & SHSTK_DATA_BIT))
@@ -296,7 +315,6 @@ static int shstk_pop_sigframe(unsigned long *ssp)
 {
 	struct vm_area_struct *vma;
 	unsigned long token_addr;
-	bool need_to_check_vma;
 	int err = 1;
 
 	/*
@@ -308,25 +326,21 @@ static int shstk_pop_sigframe(unsigned long *ssp)
 	if (!IS_ALIGNED(*ssp, 8))
 		return -EINVAL;
 
-	need_to_check_vma = PAGE_ALIGN(*ssp) == *ssp;
-
-	if (need_to_check_vma)
-		mmap_read_lock_killable(current->mm);
+	if (mmap_read_lock_killable(current->mm))
+		return -EINTR;
 
 	err = get_shstk_data(&token_addr, (unsigned long __user *)*ssp);
 	if (unlikely(err))
 		goto out_err;
 
-	if (need_to_check_vma) {
-		vma = find_vma(current->mm, *ssp);
-		if (!vma || !(vma->vm_flags & VM_SHADOW_STACK)) {
-			err = -EFAULT;
-			goto out_err;
-		}
-
-		mmap_read_unlock(current->mm);
+	vma = find_vma(current->mm, *ssp);
+	if (!vma || !(vma->vm_flags & VM_SHADOW_STACK)) {
+		err = -EFAULT;
+		goto out_err;
 	}
 
+	mmap_read_unlock(current->mm);
+
 	/* Restore SSP aligned? */
 	if (unlikely(!IS_ALIGNED(token_addr, 8)))
 		return -EINVAL;
@@ -339,8 +353,7 @@ static int shstk_pop_sigframe(unsigned long *ssp)
 
 	return 0;
 out_err:
-	if (need_to_check_vma)
-		mmap_read_unlock(current->mm);
+	mmap_read_unlock(current->mm);
 	return err;
 }
 
diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
index 02387188bad2ad2d2215319ca0d3468214fae2a4..21dac6a4892cdd71a8bc6a0be1a59c26521719d6 100644
--- a/include/linux/mmap_lock.h
+++ b/include/linux/mmap_lock.h
@@ -116,7 +116,7 @@ static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
 	__mmap_lock_trace_acquire_returned(mm, true, true);
 }
 
-static inline int mmap_write_lock_killable(struct mm_struct *mm)
+static inline int __must_check mmap_write_lock_killable(struct mm_struct *mm)
 {
 	int ret;
 
@@ -164,7 +164,7 @@ static inline void mmap_read_lock_nested(struct mm_struct *mm, int subclass)
 	__mmap_lock_trace_acquire_returned(mm, true, true);
 }
 
-static inline int mmap_read_lock_killable(struct mm_struct *mm)
+static inline int __must_check mmap_read_lock_killable(struct mm_struct *mm)
 {
 	int ret;
 
@@ -174,7 +174,7 @@ static inline int mmap_read_lock_killable(struct mm_struct *mm)
 	return ret;
 }
 
-static inline bool mmap_read_trylock(struct mm_struct *mm)
+static inline bool __must_check mmap_read_trylock(struct mm_struct *mm)
 {
 	bool ret;