get_unmapped_area handles MAP_FIXED on ia64

Handle MAP_FIXED in ia64 arch_get_unmapped_area and
hugetlb_get_unmapped_area(), just call prepare_hugepage_range in the later and
is_hugepage_only_range() in the former.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: William Irwin <bill.irwin@oracle.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/kernel/sys_ia64.c

@@ -33,6 +33,13 @@ arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len
 	if (len > RGN_MAP_LIMIT)
 		return -ENOMEM;
 
+	/* handle fixed mapping: prevent overlap with huge pages */
+	if (flags & MAP_FIXED) {
+		if (is_hugepage_only_range(mm, addr, len))
+			return -EINVAL;
+		return addr;
+	}
+
 #ifdef CONFIG_HUGETLB_PAGE
 	if (REGION_NUMBER(addr) == RGN_HPAGE)
 		addr = 0;

arch/ia64/mm/hugetlbpage.c

@@ -148,6 +148,14 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, u
 		return -ENOMEM;
 	if (len & ~HPAGE_MASK)
 		return -EINVAL;
+
+	/* Handle MAP_FIXED */
+	if (flags & MAP_FIXED) {
+		if (prepare_hugepage_range(addr, len, pgoff))
+			return -EINVAL;
+		return addr;
+	}
+
 	/* This code assumes that RGN_HPAGE != 0. */
 	if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
 		addr = HPAGE_REGION_BASE;