diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-12-09 09:17:02 +0100 |
---|---|---|
committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2013-12-09 09:19:14 +0100 |
commit | f7698ba75fa283435f5077b9dfb4319d28b9de9a (patch) | |
tree | 4bc16a615a35baaf2b482de81cd256a69067ff72 /arch/x86/lib/usercopy.c | |
parent | 798183c54799fbe1e5a5bfabb3a8c0505ffd2149 (diff) | |
parent | 374b105797c3d4f29c685f3be535c35f5689b30e (diff) |
Merge tag 'v3.13-rc3' into drm-intel-next-queued
Linux 3.13-rc3
I need a backmerge for two reasons:
- For merging the ppgtt patches from Ben I need to pull in the bdw
support.
- We now have duplicated calls to intel_uncore_forcewake_reset in the
setup code to due 2 different patches merged into -next and 3.13.
The conflict is silen so I need the merge to be able to apply
Deepak's fixup patch.
Conflicts:
drivers/gpu/drm/i915/intel_display.c
Trivial conflict, it doesn't even show up in the merge diff.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'arch/x86/lib/usercopy.c')
-rw-r--r-- | arch/x86/lib/usercopy.c | 43 |
1 files changed, 15 insertions, 28 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 4f74d94c8d9..ddf9ecb53cc 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -11,39 +11,26 @@ #include <linux/sched.h> /* - * best effort, GUP based copy_from_user() that is NMI-safe + * We rely on the nested NMI work to allow atomic faults from the NMI path; the + * nested NMI paths are careful to preserve CR2. */ unsigned long copy_from_user_nmi(void *to, const void __user *from, unsigned long n) { - unsigned long offset, addr = (unsigned long)from; - unsigned long size, len = 0; - struct page *page; - void *map; - int ret; + unsigned long ret; if (__range_not_ok(from, n, TASK_SIZE)) - return len; - - do { - ret = __get_user_pages_fast(addr, 1, 0, &page); - if (!ret) - break; - - offset = addr & (PAGE_SIZE - 1); - size = min(PAGE_SIZE - offset, n - len); - - map = kmap_atomic(page); - memcpy(to, map+offset, size); - kunmap_atomic(map); - put_page(page); - - len += size; - to += size; - addr += size; - - } while (len < n); - - return len; + return 0; + + /* + * Even though this function is typically called from NMI/IRQ context + * disable pagefaults so that its behaviour is consistent even when + * called form other contexts. + */ + pagefault_disable(); + ret = __copy_from_user_inatomic(to, from, n); + pagefault_enable(); + + return ret; } EXPORT_SYMBOL_GPL(copy_from_user_nmi); |