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authorCarsten Otte <cotte@de.ibm.com>2005-07-15 03:56:30 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-07-15 09:54:50 -0700
commitafa597ba20e9ef55fc6283c1a564854b1c9f13c0 (patch)
tree56cbfbca20a3c59ef6b1d149f67185e8e8f3a85c /mm/filemap_xip.c
parentc5287ba132ff742e595d42c28b66cbba19522c4e (diff)
downloadlinux-afa597ba20e9ef55fc6283c1a564854b1c9f13c0.tar.gz
[PATCH] execute-in-place fixes
This patch includes feedback from Andrew and Christoph. Thanks for taking time to review. Use of empty_zero_page was eliminated to fix compilation for architectures that don't have it. This patch removes setting pages up-to-date in ext2_get_xip_page and all bug checks to verify that the page is indeed up to date. Setting the page state on mapping to userland is bogus. None of the code patchs involved with these pages in mm cares about the page state. still on my ToDo list: identify a place outside second extended where __inode_direct_access should reside Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/filemap_xip.c')
-rw-r--r--mm/filemap_xip.c23
1 files changed, 8 insertions, 15 deletions
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 4553b2c5aab..8c199f53773 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -68,13 +68,12 @@ do_xip_mapping_read(struct address_space *mapping,
if (unlikely(IS_ERR(page))) {
if (PTR_ERR(page) == -ENODATA) {
/* sparse */
- page = virt_to_page(empty_zero_page);
+ page = ZERO_PAGE(0);
} else {
desc->error = PTR_ERR(page);
goto out;
}
- } else
- BUG_ON(!PageUptodate(page));
+ }
/* If users can be writing to this page using arbitrary
* virtual addresses, take care about potential aliasing
@@ -84,8 +83,7 @@ do_xip_mapping_read(struct address_space *mapping,
flush_dcache_page(page);
/*
- * Ok, we have the page, and it's up-to-date, so
- * now we can copy it to user space...
+ * Ok, we have the page, so now we can copy it to user space...
*
* The actor routine returns how many bytes were actually used..
* NOTE! This may not be the same as how much of a user buffer
@@ -164,7 +162,7 @@ EXPORT_SYMBOL_GPL(xip_file_sendfile);
* xip_write
*
* This function walks all vmas of the address_space and unmaps the
- * empty_zero_page when found at pgoff. Should it go in rmap.c?
+ * ZERO_PAGE when found at pgoff. Should it go in rmap.c?
*/
static void
__xip_unmap (struct address_space * mapping,
@@ -187,7 +185,7 @@ __xip_unmap (struct address_space * mapping,
* We need the page_table_lock to protect us from page faults,
* munmap, fork, etc...
*/
- pte = page_check_address(virt_to_page(empty_zero_page), mm,
+ pte = page_check_address(ZERO_PAGE(address), mm,
address);
if (!IS_ERR(pte)) {
/* Nuke the page table entry. */
@@ -230,7 +228,6 @@ xip_file_nopage(struct vm_area_struct * area,
page = mapping->a_ops->get_xip_page(mapping, pgoff*(PAGE_SIZE/512), 0);
if (!IS_ERR(page)) {
- BUG_ON(!PageUptodate(page));
return page;
}
if (PTR_ERR(page) != -ENODATA)
@@ -245,12 +242,11 @@ xip_file_nopage(struct vm_area_struct * area,
pgoff*(PAGE_SIZE/512), 1);
if (IS_ERR(page))
return NULL;
- BUG_ON(!PageUptodate(page));
/* unmap page at pgoff from all other vmas */
__xip_unmap(mapping, pgoff);
} else {
- /* not shared and writable, use empty_zero_page */
- page = virt_to_page(empty_zero_page);
+ /* not shared and writable, use ZERO_PAGE() */
+ page = ZERO_PAGE(address);
}
return page;
@@ -319,8 +315,6 @@ __xip_file_write(struct file *filp, const char __user *buf,
break;
}
- BUG_ON(!PageUptodate(page));
-
copied = filemap_copy_from_user(page, offset, buf, bytes);
flush_dcache_page(page);
if (likely(copied > 0)) {
@@ -435,8 +429,7 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
return 0;
else
return PTR_ERR(page);
- } else
- BUG_ON(!PageUptodate(page));
+ }
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + offset, 0, length);
kunmap_atomic(kaddr, KM_USER0);