[PATCH] madvise() does not always return -EBADF on non-file mapped area

The madvise() system call returns -EBADF for areas which does not map to
files, only for *behaviour* request MADV_WILLNEED.

According to man pages, madvise returns :

EBADF - the map exists, but the area maps something that isn't a file.

Fixes bug 2995.

Signed-off-by: Suzuki K P <suzuki@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/mm/madvise.c b/mm/madvise.c
index 73180a22877e..c8c01a12fea4 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -83,9 +83,6 @@ static long madvise_willneed(struct vm_area_struct * vma,
 {
         struct file *file = vma->vm_file;
 
-        if (!file)
-                return -EBADF;
-
         if (file->f_mapping->a_ops->get_xip_page) {
                 /* no bad return value, but ignore advice */
                 return 0;
@@ -140,11 +137,16 @@ static long madvise_dontneed(struct vm_area_struct * vma,
         return 0;
 }
 
-static long madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
-                        unsigned long start, unsigned long end, int behavior)
+static long
+madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
+                unsigned long start, unsigned long end, int behavior)
 {
+        struct file *filp = vma->vm_file;
         long error = -EBADF;
 
+        if (!filp)
+                goto  out;
+
         switch (behavior) {
         case MADV_NORMAL:
         case MADV_SEQUENTIAL:
@@ -165,6 +167,7 @@ static long madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev
                 break;
         }
                 
+out:
         return error;
 }