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| author | Daniel De Graaf <dgdegra@tycho.nsa.gov> | 2013-01-02 23:57:13 +0100 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-01-15 22:02:40 +0100 |
| commit | 1affa98d23c0188fdd4433512489be753a25bb23 (patch) | |
| tree | 7f76abc756f291798f254c543ba9e64bb848c238 /drivers/xen/gntdev.c | |
| parent | xen/gntdev: correctly unmap unlinked maps in mmu notifier (diff) | |
| download | linux-1affa98d23c0188fdd4433512489be753a25bb23.tar.xz linux-1affa98d23c0188fdd4433512489be753a25bb23.zip | |
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.c | 13 |
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; } } |