Merge tag 'v3.18' into drm-next

Linux 3.18

Backmerge Linus tree into -next as we had conflicts in i915/radeon/nouveau,
and everyone was solving them individually.

* tag 'v3.18': (57 commits)
  Linux 3.18
  watchdog: s3c2410_wdt: Fix the mask bit offset for Exynos7
  uapi: fix to export linux/vm_sockets.h
  i2c: cadence: Set the hardware time-out register to maximum value
  i2c: davinci: generate STP always when NACK is received
  ahci: disable MSI on SAMSUNG 0xa800 SSD
  context_tracking: Restore previous state in schedule_user
  slab: fix nodeid bounds check for non-contiguous node IDs
  lib/genalloc.c: export devm_gen_pool_create() for modules
  mm: fix anon_vma_clone() error treatment
  mm: fix swapoff hang after page migration and fork
  fat: fix oops on corrupted vfat fs
  ipc/sem.c: fully initialize sem_array before making it visible
  drivers/input/evdev.c: don't kfree() a vmalloc address
  cxgb4: Fill in supported link mode for SFP modules
  xen-netfront: Remove BUGs on paged skb data which crosses a page boundary
  mm/vmpressure.c: fix race in vmpressure_work_fn()
  mm: frontswap: invalidate expired data on a dup-store failure
  mm: do not overwrite reserved pages counter at show_mem()
  drm/radeon: kernel panic in drm_calc_vbltimestamp_from_scanoutpos with 3.18.0-rc6
  ...

Conflicts:
	drivers/gpu/drm/i915/intel_display.c
	drivers/gpu/drm/nouveau/nouveau_drm.c
	drivers/gpu/drm/radeon/radeon_cs.c

kernel/sched/core.c

@@ -2874,10 +2874,14 @@ asmlinkage __visible void __sched schedule_user(void)
 	 * or we have been woken up remotely but the IPI has not yet arrived,
 	 * we haven't yet exited the RCU idle mode. Do it here manually until
 	 * we find a better solution.
+	 *
+	 * NB: There are buggy callers of this function.  Ideally we
+	 * should warn if prev_state != IN_USER, but that will trigger
+	 * too frequently to make sense yet.
 	 */
-	user_exit();
+	enum ctx_state prev_state = exception_enter();
 	schedule();
-	user_enter();
+	exception_exit(prev_state);
 }
 #endif