Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "Most of the rest of MM and various other things. Some Kconfig rework
  still awaits merges of dependent trees from linux-next.

  Subsystems affected by this patch series: mm/hotfixes, mm/memcg,
  mm/vmstat, mm/thp, procfs, sysctl, misc, notifiers, core-kernel,
  bitops, lib, checkpatch, epoll, binfmt, init, rapidio, uaccess, kcov,
  ubsan, ipc, bitmap, mm/pagemap"

* akpm: (86 commits)
  mm: remove __ARCH_HAS_4LEVEL_HACK and include/asm-generic/4level-fixup.h
  um: add support for folded p4d page tables
  um: remove unused pxx_offset_proc() and addr_pte() functions
  sparc32: use pgtable-nopud instead of 4level-fixup
  parisc/hugetlb: use pgtable-nopXd instead of 4level-fixup
  parisc: use pgtable-nopXd instead of 4level-fixup
  nds32: use pgtable-nopmd instead of 4level-fixup
  microblaze: use pgtable-nopmd instead of 4level-fixup
  m68k: mm: use pgtable-nopXd instead of 4level-fixup
  m68k: nommu: use pgtable-nopud instead of 4level-fixup
  c6x: use pgtable-nopud instead of 4level-fixup
  arm: nommu: use pgtable-nopud instead of 4level-fixup
  alpha: use pgtable-nopud instead of 4level-fixup
  gpio: pca953x: tighten up indentation
  gpio: pca953x: convert to use bitmap API
  gpio: pca953x: use input from regs structure in pca953x_irq_pending()
  gpio: pca953x: remove redundant variable and check in IRQ handler
  lib/bitmap: introduce bitmap_replace() helper
  lib/test_bitmap: fix comment about this file
  lib/test_bitmap: move exp1 and exp2 upper for others to use
  ...

14 files changed, 174 insertions, 27 deletions

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 29fc933df3bf..ff335b22f23c 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -53,6 +53,7 @@
  *  bitmap_find_next_zero_area_off(buf, len, pos, n, mask)  as above
  *  bitmap_shift_right(dst, src, n, nbits)      *dst = *src >> n
  *  bitmap_shift_left(dst, src, n, nbits)       *dst = *src << n
+ *  bitmap_replace(dst, old, new, mask, nbits)  *dst = (*old & ~(*mask)) | (*new & *mask)
  *  bitmap_remap(dst, src, old, new, nbits)     *dst = map(old, new)(src)
  *  bitmap_bitremap(oldbit, old, new, nbits)    newbit = map(old, new)(oldbit)
  *  bitmap_onto(dst, orig, relmap, nbits)       *dst = orig relative to relmap
@@ -66,6 +67,8 @@
  *  bitmap_allocate_region(bitmap, pos, order)  Allocate specified bit region
  *  bitmap_from_arr32(dst, buf, nbits)          Copy nbits from u32[] buf to dst
  *  bitmap_to_arr32(buf, src, nbits)            Copy nbits from buf to u32[] dst
+ *  bitmap_get_value8(map, start)               Get 8bit value from map at start
+ *  bitmap_set_value8(map, value, start)        Set 8bit value to map at start
  *
  * Note, bitmap_zero() and bitmap_fill() operate over the region of
  * unsigned longs, that is, bits behind bitmap till the unsigned long
@@ -138,6 +141,9 @@ extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 			const unsigned long *bitmap2, unsigned int nbits);
 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 			const unsigned long *bitmap2, unsigned int nbits);
+extern void __bitmap_replace(unsigned long *dst,
+			const unsigned long *old, const unsigned long *new,
+			const unsigned long *mask, unsigned int nbits);
 extern int __bitmap_intersects(const unsigned long *bitmap1,
 			const unsigned long *bitmap2, unsigned int nbits);
 extern int __bitmap_subset(const unsigned long *bitmap1,
@@ -432,6 +438,18 @@ static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *sr
 		__bitmap_shift_left(dst, src, shift, nbits);
 }
 
+static inline void bitmap_replace(unsigned long *dst,
+				  const unsigned long *old,
+				  const unsigned long *new,
+				  const unsigned long *mask,
+				  unsigned int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = (*old & ~(*mask)) | (*new & *mask);
+	else
+		__bitmap_replace(dst, old, new, mask, nbits);
+}
+
 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 			unsigned long *maskp, int nmaskbits)
 {
@@ -489,6 +507,39 @@ static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
 		dst[1] = mask >> 32;
 }
 
+/**
+ * bitmap_get_value8 - get an 8-bit value within a memory region
+ * @map: address to the bitmap memory region
+ * @start: bit offset of the 8-bit value; must be a multiple of 8
+ *
+ * Returns the 8-bit value located at the @start bit offset within the @src
+ * memory region.
+ */
+static inline unsigned long bitmap_get_value8(const unsigned long *map,
+					      unsigned long start)
+{
+	const size_t index = BIT_WORD(start);
+	const unsigned long offset = start % BITS_PER_LONG;
+
+	return (map[index] >> offset) & 0xFF;
+}
+
+/**
+ * bitmap_set_value8 - set an 8-bit value within a memory region
+ * @map: address to the bitmap memory region
+ * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
+ * @start: bit offset of the 8-bit value; must be a multiple of 8
+ */
+static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
+				     unsigned long start)
+{
+	const size_t index = BIT_WORD(start);
+	const unsigned long offset = start % BITS_PER_LONG;
+
+	map[index] &= ~(0xFFUL << offset);
+	map[index] |= value << offset;
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __LINUX_BITMAP_H */
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index c94a9ff9f082..e479067c202c 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -47,6 +47,18 @@ extern unsigned long __sw_hweight64(__u64 w);
 	     (bit) < (size);					\
 	     (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
 
+/**
+ * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
+ * @start: bit offset to start search and to store the current iteration offset
+ * @clump: location to store copy of current 8-bit clump
+ * @bits: bitmap address to base the search on
+ * @size: bitmap size in number of bits
+ */
+#define for_each_set_clump8(start, clump, bits, size) \
+	for ((start) = find_first_clump8(&(clump), (bits), (size)); \
+	     (start) < (size); \
+	     (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
+
 static inline int get_bitmask_order(unsigned int count)
 {
 	int order;
diff --git a/include/linux/build_bug.h b/include/linux/build_bug.h
index 0fe5426f2bdc..e3a0be2c90ad 100644
--- a/include/linux/build_bug.h
+++ b/include/linux/build_bug.h
@@ -9,11 +9,11 @@
 #else /* __CHECKER__ */
 /*
  * Force a compilation error if condition is true, but also produce a
- * result (of value 0 and type size_t), so the expression can be used
+ * result (of value 0 and type int), so the expression can be used
  * e.g. in a structure initializer (or where-ever else comma expressions
  * aren't permitted).
  */
-#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); }))
+#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
 #endif /* __CHECKER__ */
 
 /* Force a compilation error if a constant expression is not a power of 2 */
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 4bd583bd6934..5b14a0f38124 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -206,7 +206,7 @@ extern struct gen_pool *devm_gen_pool_create(struct device *dev,
 		int min_alloc_order, int nid, const char *name);
 extern struct gen_pool *gen_pool_get(struct device *dev, const char *name);
 
-bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
+extern bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start,
 			size_t size);
 
 #ifdef CONFIG_OF
diff --git a/include/linux/kcov.h b/include/linux/kcov.h
index b76a1807028d..a10e84707d82 100644
--- a/include/linux/kcov.h
+++ b/include/linux/kcov.h
@@ -37,12 +37,35 @@ do {						\
 	(t)->kcov_mode &= ~KCOV_IN_CTXSW;	\
 } while (0)
 
+/* See Documentation/dev-tools/kcov.rst for usage details. */
+void kcov_remote_start(u64 handle);
+void kcov_remote_stop(void);
+u64 kcov_common_handle(void);
+
+static inline void kcov_remote_start_common(u64 id)
+{
+	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id));
+}
+
+static inline void kcov_remote_start_usb(u64 id)
+{
+	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_USB, id));
+}
+
 #else
 
 static inline void kcov_task_init(struct task_struct *t) {}
 static inline void kcov_task_exit(struct task_struct *t) {}
 static inline void kcov_prepare_switch(struct task_struct *t) {}
 static inline void kcov_finish_switch(struct task_struct *t) {}
+static inline void kcov_remote_start(u64 handle) {}
+static inline void kcov_remote_stop(void) {}
+static inline u64 kcov_common_handle(void)
+{
+	return 0;
+}
+static inline void kcov_remote_start_common(u64 id) {}
+static inline void kcov_remote_start_usb(u64 id) {}
 
 #endif /* CONFIG_KCOV */
 #endif /* _LINUX_KCOV_H */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 09f759228e3f..3adcb39fa6f5 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -348,8 +348,7 @@ int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
  * @res: Where to write the result of the conversion on success.
  *
  * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
- * Used as a replacement for the obsolete simple_strtoull. Return code must
- * be checked.
+ * Used as a replacement for the simple_strtoull. Return code must be checked.
 */
 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
 {
@@ -377,8 +376,7 @@ static inline int __must_check kstrtoul(const char *s, unsigned int base, unsign
  * @res: Where to write the result of the conversion on success.
  *
  * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
- * Used as a replacement for the obsolete simple_strtoull. Return code must
- * be checked.
+ * Used as a replacement for the simple_strtoull. Return code must be checked.
  */
 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
 {
@@ -454,7 +452,18 @@ static inline int __must_check kstrtos32_from_user(const char __user *s, size_t
 	return kstrtoint_from_user(s, count, base, res);
 }
 
-/* Obsolete, do not use.  Use kstrto<foo> instead */
+/*
+ * Use kstrto<foo> instead.
+ *
+ * NOTE: simple_strto<foo> does not check for the range overflow and,
+ *	 depending on the input, may give interesting results.
+ *
+ * Use these functions if and only if you cannot use kstrto<foo>, because
+ * the conversion ends on the first non-digit character, which may be far
+ * beyond the supported range. It might be useful to parse the strings like
+ * 10x50 or 12:21 without altering original string or temporary buffer in use.
+ * Keep in mind above caveat.
+ */
 
 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 extern long simple_strtol(const char *,char **,unsigned int);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8b0ef04b6d15..c97ea3b694e6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1838,12 +1838,12 @@ static inline void mm_dec_nr_ptes(struct mm_struct *mm) {}
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd);
 int __pte_alloc_kernel(pmd_t *pmd);
 
+#if defined(CONFIG_MMU)
+
 /*
- * The following ifdef needed to get the 4level-fixup.h header to work.
- * Remove it when 4level-fixup.h has been removed.
+ * The following ifdef needed to get the 5level-fixup.h header to work.
+ * Remove it when 5level-fixup.h has been removed.
  */
-#if defined(CONFIG_MMU) && !defined(__ARCH_HAS_4LEVEL_HACK)
-
 #ifndef __ARCH_HAS_5LEVEL_HACK
 static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
 		unsigned long address)
@@ -1865,7 +1865,7 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
 	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
 		NULL: pmd_offset(pud, address);
 }
-#endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */
+#endif /* CONFIG_MMU */
 
 #if USE_SPLIT_PTE_PTLOCKS
 #if ALLOC_SPLIT_PTLOCKS
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index 0096a05395e3..018947611483 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -150,10 +150,6 @@ extern int raw_notifier_chain_register(struct raw_notifier_head *nh,
 extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
 		struct notifier_block *nb);
 
-extern int blocking_notifier_chain_cond_register(
-		struct blocking_notifier_head *nh,
-		struct notifier_block *nb);
-
 extern int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
 		struct notifier_block *nb);
 extern int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh,
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index a705aa2d03f9..0640be56dcbd 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -58,8 +58,8 @@ extern int remove_proc_subtree(const char *, struct proc_dir_entry *);
 struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
 		struct proc_dir_entry *parent, const struct seq_operations *ops,
 		unsigned int state_size, void *data);
-#define proc_create_net(name, mode, parent, state_size, ops) \
-	proc_create_net_data(name, mode, parent, state_size, ops, NULL)
+#define proc_create_net(name, mode, parent, ops, state_size) \
+	proc_create_net_data(name, mode, parent, ops, state_size, NULL)
 struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
 		struct proc_dir_entry *parent,
 		int (*show)(struct seq_file *, void *), void *data);
diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h
index fdd421b8d9ae..724b0d036b57 100644
--- a/include/linux/rbtree_augmented.h
+++ b/include/linux/rbtree_augmented.h
@@ -283,14 +283,12 @@ __rb_erase_augmented(struct rb_node *node, struct rb_root *root,
 		__rb_change_child(node, successor, tmp, root);
 
 		if (child2) {
-			successor->__rb_parent_color = pc;
 			rb_set_parent_color(child2, parent, RB_BLACK);
 			rebalance = NULL;
 		} else {
-			unsigned long pc2 = successor->__rb_parent_color;
-			successor->__rb_parent_color = pc;
-			rebalance = __rb_is_black(pc2) ? parent : NULL;
+			rebalance = rb_is_black(successor) ? parent : NULL;
 		}
+		successor->__rb_parent_color = pc;
 		tmp = successor;
 	}
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0cd97d9dd021..467d26046416 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1210,6 +1210,8 @@ struct task_struct {
 #endif /* CONFIG_TRACING */
 
 #ifdef CONFIG_KCOV
+	/* See kernel/kcov.c for more details. */
+
 	/* Coverage collection mode enabled for this task (0 if disabled): */
 	unsigned int			kcov_mode;
 
@@ -1221,6 +1223,12 @@ struct task_struct {
 
 	/* KCOV descriptor wired with this task or NULL: */
 	struct kcov			*kcov;
+
+	/* KCOV common handle for remote coverage collection: */
+	u64				kcov_handle;
+
+	/* KCOV sequence number: */
+	int				kcov_sequence;
 #endif
 
 #ifdef CONFIG_MEMCG
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 6df477329b76..02fa84493f23 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -120,8 +120,7 @@ static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
 	struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)
 
 /* A sysctl table is an array of struct ctl_table: */
-struct ctl_table 
-{
+struct ctl_table {
 	const char *procname;		/* Text ID for /proc/sys, or zero */
 	void *data;
 	int maxlen;
@@ -140,8 +139,7 @@ struct ctl_node {
 
 /* struct ctl_table_header is used to maintain dynamic lists of
    struct ctl_table trees. */
-struct ctl_table_header
-{
+struct ctl_table_header {
 	union {
 		struct {
 			struct ctl_table *ctl_table;
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 659a4400517b..e93e249a4e9b 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -147,6 +147,8 @@ check_copy_size(const void *addr, size_t bytes, bool is_source)
 			__bad_copy_to();
 		return false;
 	}
+	if (WARN_ON_ONCE(bytes > INT_MAX))
+		return false;
 	check_object_size(addr, bytes, is_source);
 	return true;
 }
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index bdeda4b079fe..292485f3d24d 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -31,6 +31,12 @@ struct reclaim_stat {
 	unsigned nr_unmap_fail;
 };
 
+enum writeback_stat_item {
+	NR_DIRTY_THRESHOLD,
+	NR_DIRTY_BG_THRESHOLD,
+	NR_VM_WRITEBACK_STAT_ITEMS,
+};
+
 #ifdef CONFIG_VM_EVENT_COUNTERS
 /*
  * Light weight per cpu counter implementation.
@@ -381,4 +387,48 @@ static inline void __mod_zone_freepage_state(struct zone *zone, int nr_pages,
 
 extern const char * const vmstat_text[];
 
+static inline const char *zone_stat_name(enum zone_stat_item item)
+{
+	return vmstat_text[item];
+}
+
+#ifdef CONFIG_NUMA
+static inline const char *numa_stat_name(enum numa_stat_item item)
+{
+	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
+			   item];
+}
+#endif /* CONFIG_NUMA */
+
+static inline const char *node_stat_name(enum node_stat_item item)
+{
+	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
+			   NR_VM_NUMA_STAT_ITEMS +
+			   item];
+}
+
+static inline const char *lru_list_name(enum lru_list lru)
+{
+	return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
+}
+
+static inline const char *writeback_stat_name(enum writeback_stat_item item)
+{
+	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
+			   NR_VM_NUMA_STAT_ITEMS +
+			   NR_VM_NODE_STAT_ITEMS +
+			   item];
+}
+
+#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
+static inline const char *vm_event_name(enum vm_event_item item)
+{
+	return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
+			   NR_VM_NUMA_STAT_ITEMS +
+			   NR_VM_NODE_STAT_ITEMS +
+			   NR_VM_WRITEBACK_STAT_ITEMS +
+			   item];
+}
+#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
+
 #endif /* _LINUX_VMSTAT_H */