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authorDaniel De Graaf <dgdegra@tycho.nsa.gov>2013-01-03 02:57:13 +0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-01-16 01:02:40 +0400
commit1affa98d23c0188fdd4433512489be753a25bb23 (patch)
tree7f76abc756f291798f254c543ba9e64bb848c238 /drivers/xen/gntdev.c
parent16a1d0225e22e4e273e6b60a21db95decde666c2 (diff)
downloadlinux-1affa98d23c0188fdd4433512489be753a25bb23.tar.xz
xen/gntdev: remove erronous use of copy_to_user
Since there is now a mapping of granted pages in kernel address space in both PV and HVM, use it for UNMAP_NOTIFY_CLEAR_BYTE instead of accessing memory via copy_to_user and triggering sleep-in-atomic warnings. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen/gntdev.c')
-rw-r--r--drivers/xen/gntdev.c13
1 files changed, 3 insertions, 10 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 9be3e5e46d1f..3c8803feba26 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -312,17 +312,10 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
int pgno = (map->notify.addr >> PAGE_SHIFT);
- if (pgno >= offset && pgno < offset + pages && use_ptemod) {
- void __user *tmp = (void __user *)
- map->vma->vm_start + map->notify.addr;
- err = copy_to_user(tmp, &err, 1);
- if (err)
- return -EFAULT;
- map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
- } else if (pgno >= offset && pgno < offset + pages) {
- uint8_t *tmp = kmap(map->pages[pgno]);
+ if (pgno >= offset && pgno < offset + pages) {
+ /* No need for kmap, pages are in lowmem */
+ uint8_t *tmp = pfn_to_kaddr(page_to_pfn(map->pages[pgno]));
tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
- kunmap(map->pages[pgno]);
map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
}
}