Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "14 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes
  mm/vmalloc.c: don't unconditonally use __GFP_HIGHMEM
  mm/mempolicy: fix use after free when calling get_mempolicy
  mm/cma_debug.c: fix stack corruption due to sprintf usage
  signal: don't remove SIGNAL_UNKILLABLE for traced tasks.
  mm, oom: fix potential data corruption when oom_reaper races with writer
  mm: fix double mmap_sem unlock on MMF_UNSTABLE enforced SIGBUS
  slub: fix per memcg cache leak on css offline
  mm: discard memblock data later
  test_kmod: fix description for -s -and -c parameters
  kmod: fix wait on recursive loop
  wait: add wait_event_killable_timeout()
  kernel/watchdog: fix Kconfig constraints for perf hardlockup watchdog
  mm: memcontrol: fix NULL pointer crash in test_clear_page_writeback()