diff options
| author | Hugh Dickins <hugh@veritas.com> | 2005-11-22 06:32:12 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-22 18:13:42 +0100 |
| commit | 83e9b7e929d1323b9a155d186f77aa8c06155cc3 (patch) | |
| tree | 3cad39e867ca337b08bc4a7309c2b17787abd527 | |
| parent | [PATCH] unpaged: get_user_pages VM_RESERVED (diff) | |
| download | linux-83e9b7e929d1323b9a155d186f77aa8c06155cc3.tar.xz linux-83e9b7e929d1323b9a155d186f77aa8c06155cc3.zip | |
[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>
| -rw-r--r-- | mm/mmap.c | 11 | ||||
| -rw-r--r-- | mm/mprotect.c | 8 |
2 files changed, 0 insertions, 19 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 4f8def03428c..11ca5927d5ff 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) diff --git a/mm/mprotect.c b/mm/mprotect.c index 17a2b52b753b..653b8571c1ed 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -124,14 +124,6 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, * a MAP_NORESERVE private mapping to writable will now reserve. */ if (newflags & VM_WRITE) { - if (oldflags & VM_RESERVED) { - BUG_ON(oldflags & VM_WRITE); - printk(KERN_WARNING "program %s is using MAP_PRIVATE, " - "PROT_WRITE mprotect of VM_RESERVED memory, " - "which is deprecated. Please report this to " - "linux-kernel@vger.kernel.org\n",current->comm); - return -EACCES; - } if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) { charged = nrpages; if (security_vm_enough_memory(charged)) |