get_unmapped_area handles MAP_FIXED in generic code

generic arch_get_unmapped_area() now handles MAP_FIXED.  Now that all
implementations have been fixed, change the toplevel get_unmapped_area() to
call into arch or drivers for the MAP_FIXED case.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Irwin <bill.irwin@oracle.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 11 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 88da687bde89..a6b7c796352b 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1200,6 +1200,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
         if (len > TASK_SIZE)
                 return -ENOMEM;
 
+        if (flags & MAP_FIXED)
+                return addr;
+
         if (addr) {
                 addr = PAGE_ALIGN(addr);
                 vma = find_vma(mm, addr);
@@ -1273,6 +1276,9 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
         if (len > TASK_SIZE)
                 return -ENOMEM;
 
+        if (flags & MAP_FIXED)
+                return addr;
+
         /* requesting a specific address */
         if (addr) {
                 addr = PAGE_ALIGN(addr);
@@ -1361,22 +1367,21 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
                 unsigned long pgoff, unsigned long flags)
 {
         unsigned long ret;
-
-        if (!(flags & MAP_FIXED)) {
-                unsigned long (*get_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
-
-                get_area = current->mm->get_unmapped_area;
-                if (file && file->f_op && file->f_op->get_unmapped_area)
-                        get_area = file->f_op->get_unmapped_area;
-                addr = get_area(file, addr, len, pgoff, flags);
-                if (IS_ERR_VALUE(addr))
-                        return addr;
-        }
+        unsigned long (*get_area)(struct file *, unsigned long,
+                                  unsigned long, unsigned long, unsigned long);
+
+        get_area = current->mm->get_unmapped_area;
+        if (file && file->f_op && file->f_op->get_unmapped_area)
+                get_area = file->f_op->get_unmapped_area;
+        addr = get_area(file, addr, len, pgoff, flags);
+        if (IS_ERR_VALUE(addr))
+                return addr;
 
         if (addr > TASK_SIZE - len)
                 return -ENOMEM;
         if (addr & ~PAGE_MASK)
                 return -EINVAL;
+
         if (file && is_file_hugepages(file))  {
                 /*
                  * Check if the given range is hugepage aligned, and