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[PATCH] unpaged: private write VM_RESERVED

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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>
This commit is contained in:
Hugh Dickins
2005-11-21 21:32:12 -08:00
committed by Linus Torvalds
parent ed5297a940
commit 83e9b7e929
2 changed files with 0 additions and 19 deletions
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11
mm/mmap.c
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@@ -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)