Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: don't defer struct page initialization for Xen pv guests
  lib/Kconfig.debug: enable RUNTIME_TESTING_MENU
  vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
  selftests/memfd: add run_fuse_test.sh to TEST_FILES
  bug.h: work around GCC PR82365 in BUG()
  mm/swap.c: make functions and their kernel-doc agree (again)
  mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc
  ida: do zeroing in ida_pre_get()
  mm, swap, frontswap: fix THP swap if frontswap enabled
  certs/blacklist_nohashes.c: fix const confusion in certs blacklist
  kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
  mm, mlock, vmscan: no more skipping pagevecs
  mm: memcontrol: fix NR_WRITEBACK leak in memcg and system stats
  Kbuild: always define endianess in kconfig.h
  include/linux/sched/mm.h: re-inline mmdrop()
  tools: fix cross-compile var clobbering

7 files changed, 54 insertions, 12 deletions

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 963b755d19b0..a7613e1b0c87 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -52,6 +52,7 @@ struct bug_entry {
 #ifndef HAVE_ARCH_BUG
 #define BUG() do { \
 	printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
+	barrier_before_unreachable(); \
 	panic("BUG!"); \
 } while (0)
 #endif
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 73bc63e0a1c4..901c1ccb3374 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -208,6 +208,15 @@
 #endif
 
 /*
+ * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
+ * confuse the stack allocation in gcc, leading to overly large stack
+ * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
+ *
+ * Adding an empty inline assembly before it works around the problem
+ */
+#define barrier_before_unreachable() asm volatile("")
+
+/*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer
  * control elsewhere.
@@ -217,7 +226,11 @@
  * unreleased.  Really, we need to have autoconf for the kernel.
  */
 #define unreachable() \
-	do { annotate_unreachable(); __builtin_unreachable(); } while (0)
+	do {					\
+		annotate_unreachable();		\
+		barrier_before_unreachable();	\
+		__builtin_unreachable();	\
+	} while (0)
 
 /* Mark a function definition as prohibited from being cloned. */
 #define __noclone	__attribute__((__noclone__, __optimize__("no-tracer")))
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index e835fc0423ec..ab4711c63601 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -86,6 +86,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
 # define barrier_data(ptr) barrier()
 #endif
 
+/* workaround for GCC PR82365 if needed */
+#ifndef barrier_before_unreachable
+# define barrier_before_unreachable() do { } while (0)
+#endif
+
 /* Unreachable code */
 #ifdef CONFIG_STACK_VALIDATION
 /*
diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
index c5fd4ee776ba..dcde9471897d 100644
--- a/include/linux/kconfig.h
+++ b/include/linux/kconfig.h
@@ -4,6 +4,12 @@
 
 #include <generated/autoconf.h>
 
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define __BIG_ENDIAN 4321
+#else
+#define __LITTLE_ENDIAN 1234
+#endif
+
 #define __ARG_PLACEHOLDER_1 0,
 #define __take_second_arg(__ignored, val, ...) val
 
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 882046863581..c46016bb25eb 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -523,9 +523,11 @@ static inline void __mod_memcg_state(struct mem_cgroup *memcg,
 static inline void mod_memcg_state(struct mem_cgroup *memcg,
 				   int idx, int val)
 {
-	preempt_disable();
+	unsigned long flags;
+
+	local_irq_save(flags);
 	__mod_memcg_state(memcg, idx, val);
-	preempt_enable();
+	local_irq_restore(flags);
 }
 
 /**
@@ -606,9 +608,11 @@ static inline void __mod_lruvec_state(struct lruvec *lruvec,
 static inline void mod_lruvec_state(struct lruvec *lruvec,
 				    enum node_stat_item idx, int val)
 {
-	preempt_disable();
+	unsigned long flags;
+
+	local_irq_save(flags);
 	__mod_lruvec_state(lruvec, idx, val);
-	preempt_enable();
+	local_irq_restore(flags);
 }
 
 static inline void __mod_lruvec_page_state(struct page *page,
@@ -630,9 +634,11 @@ static inline void __mod_lruvec_page_state(struct page *page,
 static inline void mod_lruvec_page_state(struct page *page,
 					 enum node_stat_item idx, int val)
 {
-	preempt_disable();
+	unsigned long flags;
+
+	local_irq_save(flags);
 	__mod_lruvec_page_state(page, idx, val);
-	preempt_enable();
+	local_irq_restore(flags);
 }
 
 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
@@ -659,9 +665,11 @@ static inline void __count_memcg_events(struct mem_cgroup *memcg,
 static inline void count_memcg_events(struct mem_cgroup *memcg,
 				      int idx, unsigned long count)
 {
-	preempt_disable();
+	unsigned long flags;
+
+	local_irq_save(flags);
 	__count_memcg_events(memcg, idx, count);
-	preempt_enable();
+	local_irq_restore(flags);
 }
 
 /* idx can be of type enum memcg_event_item or vm_event_item */
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 1149533aa2fa..9806184bb3d5 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -36,7 +36,18 @@ static inline void mmgrab(struct mm_struct *mm)
 	atomic_inc(&mm->mm_count);
 }
 
-extern void mmdrop(struct mm_struct *mm);
+extern void __mmdrop(struct mm_struct *mm);
+
+static inline void mmdrop(struct mm_struct *mm)
+{
+	/*
+	 * The implicit full barrier implied by atomic_dec_and_test() is
+	 * required by the membarrier system call before returning to
+	 * user-space, after storing to rq->curr.
+	 */
+	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
+		__mmdrop(mm);
+}
 
 /**
  * mmget() - Pin the address space associated with a &struct mm_struct.
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 7b6a59f722a3..a1a3f4ed94ce 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -337,8 +337,6 @@ extern void deactivate_file_page(struct page *page);
 extern void mark_page_lazyfree(struct page *page);
 extern void swap_setup(void);
 
-extern void add_page_to_unevictable_list(struct page *page);
-
 extern void lru_cache_add_active_or_unevictable(struct page *page,
 						struct vm_area_struct *vma);