1 files changed, 34 insertions, 5 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index 5189b5aed8c0..6f9248f89bde 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1143,9 +1143,6 @@ static int do_mmap_private(struct vm_area_struct *vma,
                 if (ret < rlen)
                         memset(base + ret, 0, rlen - ret);
 
-        } else {
-                /* if it's an anonymous mapping, then just clear it */
-                memset(base, 0, rlen);
         }
 
         return 0;
@@ -1343,6 +1340,11 @@ unsigned long do_mmap_pgoff(struct file *file,
                 goto error_just_free;
         add_nommu_region(region);
 
+        /* clear anonymous mappings that don't ask for uninitialized data */
+        if (!vma->vm_file && !(flags & MAP_UNINITIALIZED))
+                memset((void *)region->vm_start, 0,
+                       region->vm_end - region->vm_start);
+
         /* okay... we have a mapping; now we have to register it */
         result = vma->vm_start;
 
@@ -1362,9 +1364,11 @@ share:
 error_just_free:
         up_write(&nommu_region_sem);
 error:
-        fput(region->vm_file);
+        if (region->vm_file)
+                fput(region->vm_file);
         kmem_cache_free(vm_region_jar, region);
-        fput(vma->vm_file);
+        if (vma->vm_file)
+                fput(vma->vm_file);
         if (vma->vm_flags & VM_EXECUTABLE)
                 removed_exe_file_vma(vma->vm_mm);
         kmem_cache_free(vm_area_cachep, vma);
@@ -1394,6 +1398,31 @@ error_getting_region:
 }
 EXPORT_SYMBOL(do_mmap_pgoff);
 
+SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
+                unsigned long, prot, unsigned long, flags,
+                unsigned long, fd, unsigned long, pgoff)
+{
+        struct file *file = NULL;
+        unsigned long retval = -EBADF;
+
+        if (!(flags & MAP_ANONYMOUS)) {
+                file = fget(fd);
+                if (!file)
+                        goto out;
+        }
+
+        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+
+        down_write(&current->mm->mmap_sem);
+        retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+        up_write(&current->mm->mmap_sem);
+
+        if (file)
+                fput(file);
+out:
+        return retval;
+}
+
 /*
  * split a vma into two pieces at address 'addr', a new vma is allocated either
  * for the first part or the tail.