[PATCH] hugetlbpage MAP_FIXED fix

We need to validate that the address and length of a MAP_FIXED request are
suitable for hugetlb pages.

arch/i386/mm/hugetlbpage.c

@@ -88,6 +88,18 @@ static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma, struc
 	set_pte(page_table, entry);
 }
 
+/*
+ * This function checks for proper alignment of input addr and len parameters.
+ */
+int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
+{
+	if (len & ~HPAGE_MASK)
+		return -EINVAL;
+	if (addr & ~HPAGE_MASK)
+		return -EINVAL;
+	return 0;
+}
+
 int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 			struct vm_area_struct *vma)
 {

arch/ia64/mm/hugetlbpage.c

@@ -96,6 +96,18 @@ set_huge_pte (struct mm_struct *mm, struct vm_area_struct *vma,
 	return;
 }
 
+/*
+ * This function checks for proper alignment of input addr and len parameters.
+ */
+int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
+{
+	if (len & ~HPAGE_MASK)
+		return -EINVAL;
+	if (addr & ~HPAGE_MASK)
+		return -EINVAL;
+	return 0;
+}
+
 int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 			struct vm_area_struct *vma)
 {

arch/sparc64/mm/hugetlbpage.c

@@ -232,6 +232,18 @@ make_hugetlb_pages_present(unsigned long addr, unsigned long end, int flags)
 	return -1;
 }
 
+/*
+ * This function checks for proper alignment of input addr and len parameters.
+ */
+int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
+{
+	if (len & ~HPAGE_MASK)
+		return -EINVAL;
+	if (addr & ~HPAGE_MASK)
+		return -EINVAL;
+	return 0;
+}
+
 int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 			    struct vm_area_struct *vma)
 {

arch/x86_64/mm/hugetlbpage.c

@@ -86,6 +86,18 @@ static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma, struc
 	set_pte(page_table, entry);
 }
 
+/*
+ * This function checks for proper alignment of input addr and len parameters.
+ */
+int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
+{
+	if (len & ~HPAGE_MASK)
+		return -EINVAL;
+	if (addr & ~HPAGE_MASK)
+		return -EINVAL;
+	return 0;
+}
+
 int
 copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 			struct vm_area_struct *vma)

include/linux/hugetlb.h

@@ -26,6 +26,7 @@ struct vm_area_struct *hugepage_vma(struct mm_struct *mm,
 					unsigned long address);
 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 				pmd_t *pmd, int write);
+int is_aligned_hugepage_range(unsigned long addr, unsigned long len);
 int pmd_huge(pmd_t pmd);
 
 extern int htlbpage_max;
@@ -56,6 +57,7 @@ static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
 #define hugepage_vma(mm, addr)			0
 #define mark_mm_hugetlb(mm, vma)		do { } while (0)
 #define follow_huge_pmd(mm, addr, pmd, write)	0
+#define is_aligned_hugepage_range(addr, len)	0
 #define pmd_huge(x)	0
 
 #ifndef HPAGE_MASK

mm/mmap.c

@@ -801,6 +801,13 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 			return -ENOMEM;
 		if (addr & ~PAGE_MASK)
 			return -EINVAL;
+		if (is_file_hugepages(file)) {
+			unsigned long ret;
+
+			ret = is_aligned_hugepage_range(addr, len);
+			if (ret)
+				return ret;
+		}
 		return addr;
 	}
 
@@ -1224,8 +1231,10 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
 	/* we have  start < mpnt->vm_end  */
 
 	if (is_vm_hugetlb_page(mpnt)) {
-		if ((start & ~HPAGE_MASK) || (len & ~HPAGE_MASK))
-			return -EINVAL;
+		int ret = is_aligned_hugepage_range(start, len);
+
+		if (ret)
+			return ret;
 	}
 
 	/* if it doesn't overlap, we have nothing.. */