[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>

diff --git a/mm/madvise.c b/mm/madvise.c
index 73180a2..c8c01a1 100644 (file)
--- 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;
 }