1 files changed, 2 insertions, 89 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index d8c02fbe03b5..eb3e2e558da1 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -111,94 +111,6 @@ unsigned int kobjsize(const void *objp)
 	return PAGE_SIZE << compound_order(page);
 }
 
-static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-		      unsigned long start, unsigned long nr_pages,
-		      unsigned int foll_flags, struct page **pages,
-		      struct vm_area_struct **vmas, int *nonblocking)
-{
-	struct vm_area_struct *vma;
-	unsigned long vm_flags;
-	int i;
-
-	/* calculate required read or write permissions.
-	 * If FOLL_FORCE is set, we only require the "MAY" flags.
-	 */
-	vm_flags  = (foll_flags & FOLL_WRITE) ?
-			(VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
-	vm_flags &= (foll_flags & FOLL_FORCE) ?
-			(VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
-
-	for (i = 0; i < nr_pages; i++) {
-		vma = find_vma(mm, start);
-		if (!vma)
-			goto finish_or_fault;
-
-		/* protect what we can, including chardevs */
-		if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
-		    !(vm_flags & vma->vm_flags))
-			goto finish_or_fault;
-
-		if (pages) {
-			pages[i] = virt_to_page(start);
-			if (pages[i])
-				get_page(pages[i]);
-		}
-		if (vmas)
-			vmas[i] = vma;
-		start = (start + PAGE_SIZE) & PAGE_MASK;
-	}
-
-	return i;
-
-finish_or_fault:
-	return i ? : -EFAULT;
-}
-
-/*
- * get a list of pages in an address range belonging to the specified process
- * and indicate the VMA that covers each page
- * - this is potentially dodgy as we may end incrementing the page count of a
- *   slab page or a secondary page from a compound page
- * - don't permit access to VMAs that don't support it, such as I/O mappings
- */
-long get_user_pages(unsigned long start, unsigned long nr_pages,
-		    unsigned int gup_flags, struct page **pages,
-		    struct vm_area_struct **vmas)
-{
-	return __get_user_pages(current, current->mm, start, nr_pages,
-				gup_flags, pages, vmas, NULL);
-}
-EXPORT_SYMBOL(get_user_pages);
-
-long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
-			    unsigned int gup_flags, struct page **pages,
-			    int *locked)
-{
-	return get_user_pages(start, nr_pages, gup_flags, pages, NULL);
-}
-EXPORT_SYMBOL(get_user_pages_locked);
-
-static long __get_user_pages_unlocked(struct task_struct *tsk,
-			struct mm_struct *mm, unsigned long start,
-			unsigned long nr_pages, struct page **pages,
-			unsigned int gup_flags)
-{
-	long ret;
-	down_read(&mm->mmap_sem);
-	ret = __get_user_pages(tsk, mm, start, nr_pages, gup_flags, pages,
-				NULL, NULL);
-	up_read(&mm->mmap_sem);
-	return ret;
-}
-
-long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
-			     struct page **pages, unsigned int gup_flags)
-{
-	return __get_user_pages_unlocked(current, current->mm, start, nr_pages,
-					 pages, gup_flags);
-}
-EXPORT_SYMBOL(get_user_pages_unlocked);
-
 /**
  * follow_pfn - look up PFN at a user virtual address
  * @vma: memory mapping
@@ -1792,7 +1704,8 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
 	struct vm_area_struct *vma;
 	int write = gup_flags & FOLL_WRITE;
 
-	down_read(&mm->mmap_sem);
+	if (down_read_killable(&mm->mmap_sem))
+		return 0;
 
 	/* the access must start within one of the target process's mappings */
 	vma = find_vma(mm, addr);