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()

4 files changed, 71 insertions, 4 deletions

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 77d427974f57..bae11c7e7bf3 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -61,6 +61,7 @@ extern int memblock_debug;
 #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
 #define __init_memblock __meminit
 #define __initdata_memblock __meminitdata
+void memblock_discard(void);
 #else
 #define __init_memblock
 #define __initdata_memblock
@@ -74,8 +75,6 @@ phys_addr_t memblock_find_in_range_node(phys_addr_t size, phys_addr_t align,
 					int nid, ulong flags);
 phys_addr_t memblock_find_in_range(phys_addr_t start, phys_addr_t end,
 				   phys_addr_t size, phys_addr_t align);
-phys_addr_t get_allocated_memblock_reserved_regions_info(phys_addr_t *addr);
-phys_addr_t get_allocated_memblock_memory_regions_info(phys_addr_t *addr);
 void memblock_allow_resize(void);
 int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid);
 int memblock_add(phys_addr_t base, phys_addr_t size);
@@ -110,6 +109,9 @@ void __next_mem_range_rev(u64 *idx, int nid, ulong flags,
 void __next_reserved_mem_region(u64 *idx, phys_addr_t *out_start,
 				phys_addr_t *out_end);
 
+void __memblock_free_early(phys_addr_t base, phys_addr_t size);
+void __memblock_free_late(phys_addr_t base, phys_addr_t size);
+
 /**
  * for_each_mem_range - iterate through memblock areas from type_a and not
  * included in type_b. Or just type_a if type_b is NULL.
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 3914e3dd6168..9b15a4bcfa77 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -484,7 +484,8 @@ bool mem_cgroup_oom_synchronize(bool wait);
 extern int do_swap_account;
 #endif
 
-void lock_page_memcg(struct page *page);
+struct mem_cgroup *lock_page_memcg(struct page *page);
+void __unlock_page_memcg(struct mem_cgroup *memcg);
 void unlock_page_memcg(struct page *page);
 
 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg,
@@ -809,7 +810,12 @@ mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 {
 }
 
-static inline void lock_page_memcg(struct page *page)
+static inline struct mem_cgroup *lock_page_memcg(struct page *page)
+{
+	return NULL;
+}
+
+static inline void __unlock_page_memcg(struct mem_cgroup *memcg)
 {
 }
 
diff --git a/include/linux/oom.h b/include/linux/oom.h
index 8a266e2be5a6..76aac4ce39bc 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -6,6 +6,8 @@
 #include <linux/types.h>
 #include <linux/nodemask.h>
 #include <uapi/linux/oom.h>
+#include <linux/sched/coredump.h> /* MMF_* */
+#include <linux/mm.h> /* VM_FAULT* */
 
 struct zonelist;
 struct notifier_block;
@@ -63,6 +65,26 @@ static inline bool tsk_is_oom_victim(struct task_struct * tsk)
 	return tsk->signal->oom_mm;
 }
 
+/*
+ * Checks whether a page fault on the given mm is still reliable.
+ * This is no longer true if the oom reaper started to reap the
+ * address space which is reflected by MMF_UNSTABLE flag set in
+ * the mm. At that moment any !shared mapping would lose the content
+ * and could cause a memory corruption (zero pages instead of the
+ * original content).
+ *
+ * User should call this before establishing a page table entry for
+ * a !shared mapping and under the proper page table lock.
+ *
+ * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise.
+ */
+static inline int check_stable_address_space(struct mm_struct *mm)
+{
+	if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags)))
+		return VM_FAULT_SIGBUS;
+	return 0;
+}
+
 extern unsigned long oom_badness(struct task_struct *p,
 		struct mem_cgroup *memcg, const nodemask_t *nodemask,
 		unsigned long totalpages);
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 5b74e36c0ca8..dc19880c02f5 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -757,6 +757,43 @@ extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
 	__ret;									\
 })
 
+#define __wait_event_killable_timeout(wq_head, condition, timeout)		\
+	___wait_event(wq_head, ___wait_cond_timeout(condition),			\
+		      TASK_KILLABLE, 0, timeout,				\
+		      __ret = schedule_timeout(__ret))
+
+/**
+ * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
+ * @wq_head: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_KILLABLE) until the
+ * @condition evaluates to true or a kill signal is received.
+ * The @condition is checked each time the waitqueue @wq_head is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * Returns:
+ * 0 if the @condition evaluated to %false after the @timeout elapsed,
+ * 1 if the @condition evaluated to %true after the @timeout elapsed,
+ * the remaining jiffies (at least 1) if the @condition evaluated
+ * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
+ * interrupted by a kill signal.
+ *
+ * Only kill signals interrupt this process.
+ */
+#define wait_event_killable_timeout(wq_head, condition, timeout)		\
+({										\
+	long __ret = timeout;							\
+	might_sleep();								\
+	if (!___wait_cond_timeout(condition))					\
+		__ret = __wait_event_killable_timeout(wq_head,			\
+						condition, timeout);		\
+	__ret;									\
+})
+
 
 #define __wait_event_lock_irq(wq_head, condition, lock, cmd)			\
 	(void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,	\