[PATCH] unpaged: private write VM_RESERVED

The PageReserved removal in 2.6.15-rc1 issued a "deprecated" message when you
tried to mmap or mprotect MAP_PRIVATE PROT_WRITE a VM_RESERVED, and failed
with -EACCES: because do_wp_page lacks the refinement to COW pages in those
areas, nor do we expect to find anonymous pages in them; and it seemed just
bloat to add code for handling such a peculiar case.  But immediately it
caused vbetool and ddcprobe (using lrmi) to fail.

So revert the "deprecated" messages, letting mmap and mprotect succeed.  But
leave do_wp_page's BUG_ON(vma->vm_flags & VM_RESERVED) in place until we've
added the code to do it right: so this particular patch is only good if the
app doesn't really need to write to that private area.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 11 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 4f8def0..11ca592 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1076,17 +1076,6 @@ munmap_back:
 		error = file->f_op->mmap(file, vma);
 		if (error)
 			goto unmap_and_free_vma;
-		if ((vma->vm_flags & (VM_SHARED | VM_WRITE | VM_RESERVED))
-						== (VM_WRITE | VM_RESERVED)) {
-			printk(KERN_WARNING "program %s is using MAP_PRIVATE, "
-				"PROT_WRITE mmap of VM_RESERVED memory, which "
-				"is deprecated. Please report this to "
-				"linux-kernel@vger.kernel.org\n",current->comm);
-			if (vma->vm_ops && vma->vm_ops->close)
-				vma->vm_ops->close(vma);
-			error = -EACCES;
-			goto unmap_and_free_vma;
-		}
 	} else if (vm_flags & VM_SHARED) {
 		error = shmem_zero_setup(vma);
 		if (error)