Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kasan: do not sanitize kexec purgatory
  drivers/rapidio/devices/tsi721.c: make module parameter variable name unique
  mm/hugetlb.c: don't call region_abort if region_chg fails
  kasan: report only the first error by default
  hugetlbfs: initialize shared policy as part of inode allocation
  mm: fix section name for .data..ro_after_init
  mm, hugetlb: use pte_present() instead of pmd_present() in follow_huge_pmd()
  mm: workingset: fix premature shadow node shrinking with cgroups
  mm: rmap: fix huge file mmap accounting in the memcg stats
  mm: move mm_percpu_wq initialization earlier
  mm: migrate: fix remove_migration_pte() for ksm pages

22 files changed, 104 insertions, 42 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 2ba45caabada..facc20a3f962 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1725,6 +1725,12 @@
 			kernel and module base offset ASLR (Address Space
 			Layout Randomization).
 
+	kasan_multi_shot
+			[KNL] Enforce KASAN (Kernel Address Sanitizer) to print
+			report on every invalid memory access. Without this
+			parameter KASAN will print report only for the first
+			invalid access.
+
 	keepinitrd	[HW,ARM]
 
 	kernelcore=	[KNL,X86,IA-64,PPC]
diff --git a/arch/s390/include/asm/sections.h b/arch/s390/include/asm/sections.h
index 5ce29fe100ba..fbd9116eb17b 100644
--- a/arch/s390/include/asm/sections.h
+++ b/arch/s390/include/asm/sections.h
@@ -4,6 +4,5 @@
 #include <asm-generic/sections.h>
 
 extern char _eshared[], _ehead[];
-extern char __start_ro_after_init[], __end_ro_after_init[];
 
 #endif
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 5ccf95396251..72307f108c40 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -63,11 +63,9 @@ SECTIONS
 
 	. = ALIGN(PAGE_SIZE);
 	__start_ro_after_init = .;
-	__start_data_ro_after_init = .;
 	.data..ro_after_init : {
 		 *(.data..ro_after_init)
 	}
-	__end_data_ro_after_init = .;
 	EXCEPTION_TABLE(16)
 	. = ALIGN(PAGE_SIZE);
 	__end_ro_after_init = .;
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 555b9fa0ad43..7dbdb780264d 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -8,6 +8,7 @@ PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
 LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib
 targets += purgatory.ro
 
+KASAN_SANITIZE	:= n
 KCOV_INSTRUMENT := n
 
 # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index 9d19b9a62011..315a4be8dc1e 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -37,8 +37,8 @@
 #include "tsi721.h"
 
 #ifdef DEBUG
-u32 dbg_level;
-module_param(dbg_level, uint, S_IWUSR | S_IRUGO);
+u32 tsi_dbg_level;
+module_param_named(dbg_level, tsi_dbg_level, uint, S_IWUSR | S_IRUGO);
 MODULE_PARM_DESC(dbg_level, "Debugging output level (default 0 = none)");
 #endif
 
diff --git a/drivers/rapidio/devices/tsi721.h b/drivers/rapidio/devices/tsi721.h
index 5941437cbdd1..957eadc58150 100644
--- a/drivers/rapidio/devices/tsi721.h
+++ b/drivers/rapidio/devices/tsi721.h
@@ -40,11 +40,11 @@ enum {
 };
 
 #ifdef DEBUG
-extern u32 dbg_level;
+extern u32 tsi_dbg_level;
 
 #define tsi_debug(level, dev, fmt, arg...)				\
 	do {								\
-		if (DBG_##level & dbg_level)				\
+		if (DBG_##level & tsi_dbg_level)				\
 			dev_dbg(dev, "%s: " fmt "\n", __func__, ##arg);	\
 	} while (0)
 #else
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 8f96461236f6..7163fe014b57 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -695,14 +695,11 @@ static struct inode *hugetlbfs_get_root(struct super_block *sb,
 
 	inode = new_inode(sb);
 	if (inode) {
-		struct hugetlbfs_inode_info *info;
 		inode->i_ino = get_next_ino();
 		inode->i_mode = S_IFDIR | config->mode;
 		inode->i_uid = config->uid;
 		inode->i_gid = config->gid;
 		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
-		info = HUGETLBFS_I(inode);
-		mpol_shared_policy_init(&info->policy, NULL);
 		inode->i_op = &hugetlbfs_dir_inode_operations;
 		inode->i_fop = &simple_dir_operations;
 		/* directory inodes start off with i_nlink == 2 (for "." entry) */
@@ -733,7 +730,6 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 
 	inode = new_inode(sb);
 	if (inode) {
-		struct hugetlbfs_inode_info *info;
 		inode->i_ino = get_next_ino();
 		inode_init_owner(inode, dir, mode);
 		lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
@@ -741,15 +737,6 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
 		inode->i_mapping->a_ops = &hugetlbfs_aops;
 		inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 		inode->i_mapping->private_data = resv_map;
-		info = HUGETLBFS_I(inode);
-		/*
-		 * The policy is initialized here even if we are creating a
-		 * private inode because initialization simply creates an
-		 * an empty rb tree and calls rwlock_init(), later when we
-		 * call mpol_free_shared_policy() it will just return because
-		 * the rb tree will still be empty.
-		 */
-		mpol_shared_policy_init(&info->policy, NULL);
 		switch (mode & S_IFMT) {
 		default:
 			init_special_inode(inode, mode, dev);
@@ -937,6 +924,18 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
 		hugetlbfs_inc_free_inodes(sbinfo);
 		return NULL;
 	}
+
+	/*
+	 * Any time after allocation, hugetlbfs_destroy_inode can be called
+	 * for the inode.  mpol_free_shared_policy is unconditionally called
+	 * as part of hugetlbfs_destroy_inode.  So, initialize policy here
+	 * in case of a quick call to destroy.
+	 *
+	 * Note that the policy is initialized even if we are creating a
+	 * private inode.  This simplifies hugetlbfs_destroy_inode.
+	 */
+	mpol_shared_policy_init(&p->policy, NULL);
+
 	return &p->vfs_inode;
 }
 
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 4df64a1fc09e..532372c6cf15 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -14,8 +14,8 @@
  * [_sdata, _edata]: contains .data.* sections, may also contain .rodata.*
  *                   and/or .init.* sections.
  * [__start_rodata, __end_rodata]: contains .rodata.* sections
- * [__start_data_ro_after_init, __end_data_ro_after_init]:
- *		     contains data.ro_after_init section
+ * [__start_ro_after_init, __end_ro_after_init]:
+ *		     contains .data..ro_after_init section
  * [__init_begin, __init_end]: contains .init.* sections, but .init.text.*
  *                   may be out of this range on some architectures.
  * [_sinittext, _einittext]: contains .init.text.* sections
@@ -33,7 +33,7 @@ extern char _data[], _sdata[], _edata[];
 extern char __bss_start[], __bss_stop[];
 extern char __init_begin[], __init_end[];
 extern char _sinittext[], _einittext[];
-extern char __start_data_ro_after_init[], __end_data_ro_after_init[];
+extern char __start_ro_after_init[], __end_ro_after_init[];
 extern char _end[];
 extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
 extern char __kprobes_text_start[], __kprobes_text_end[];
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 0968d13b3885..f9f21e2c59f3 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -260,9 +260,9 @@
  */
 #ifndef RO_AFTER_INIT_DATA
 #define RO_AFTER_INIT_DATA						\
-	__start_data_ro_after_init = .;					\
+	__start_ro_after_init = .;					\
 	*(.data..ro_after_init)						\
-	__end_data_ro_after_init = .;
+	__end_ro_after_init = .;
 #endif
 
 /*
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 5734480c9590..a5c7046f26b4 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -76,6 +76,9 @@ size_t ksize(const void *);
 static inline void kasan_unpoison_slab(const void *ptr) { ksize(ptr); }
 size_t kasan_metadata_size(struct kmem_cache *cache);
 
+bool kasan_save_enable_multi_shot(void);
+void kasan_restore_multi_shot(bool enabled);
+
 #else /* CONFIG_KASAN */
 
 static inline void kasan_unpoison_shadow(const void *address, size_t size) {}
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 5af377303880..bb7250c45cb8 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -740,6 +740,12 @@ static inline bool mem_cgroup_oom_synchronize(bool wait)
 	return false;
 }
 
+static inline void mem_cgroup_update_page_stat(struct page *page,
+					       enum mem_cgroup_stat_index idx,
+					       int nr)
+{
+}
+
 static inline void mem_cgroup_inc_page_stat(struct page *page,
 					    enum mem_cgroup_stat_index idx)
 {
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5f01c88f0800..00a8fa7e366a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -32,6 +32,8 @@ struct user_struct;
 struct writeback_control;
 struct bdi_writeback;
 
+void init_mm_internals(void);
+
 #ifndef CONFIG_NEED_MULTIPLE_NODES	/* Don't use mapnrs, do it properly */
 extern unsigned long max_mapnr;
 
diff --git a/init/main.c b/init/main.c
index f9c9d9948203..b0c11cbf5ddf 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1022,6 +1022,8 @@ static noinline void __init kernel_init_freeable(void)
 
 	workqueue_init();
 
+	init_mm_internals();
+
 	do_pre_smp_initcalls();
 	lockup_detector_init();
 
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 0b1d3140fbb8..a25c9763fce1 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -20,6 +20,7 @@
 #include <linux/string.h>
 #include <linux/uaccess.h>
 #include <linux/module.h>
+#include <linux/kasan.h>
 
 /*
  * Note: test functions are marked noinline so that their names appear in
@@ -474,6 +475,12 @@ static noinline void __init use_after_scope_test(void)
 
 static int __init kmalloc_tests_init(void)
 {
+	/*
+	 * Temporarily enable multi-shot mode. Otherwise, we'd only get a
+	 * report for the first case.
+	 */
+	bool multishot = kasan_save_enable_multi_shot();
+
 	kmalloc_oob_right();
 	kmalloc_oob_left();
 	kmalloc_node_oob_right();
@@ -499,6 +506,9 @@ static int __init kmalloc_tests_init(void)
 	ksize_unpoisons_memory();
 	copy_user_test();
 	use_after_scope_test();
+
+	kasan_restore_multi_shot(multishot);
+
 	return -EAGAIN;
 }
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3d0aab9ee80d..e5828875f7bb 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4403,7 +4403,9 @@ int hugetlb_reserve_pages(struct inode *inode,
 	return 0;
 out_err:
 	if (!vma || vma->vm_flags & VM_MAYSHARE)
-		region_abort(resv_map, from, to);
+		/* Don't call region_abort if region_chg failed */
+		if (chg >= 0)
+			region_abort(resv_map, from, to);
 	if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
 		kref_put(&resv_map->refs, resv_map_release);
 	return ret;
@@ -4651,6 +4653,7 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 {
 	struct page *page = NULL;
 	spinlock_t *ptl;
+	pte_t pte;
 retry:
 	ptl = pmd_lockptr(mm, pmd);
 	spin_lock(ptl);
@@ -4660,12 +4663,13 @@ retry:
 	 */
 	if (!pmd_huge(*pmd))
 		goto out;
-	if (pmd_present(*pmd)) {
+	pte = huge_ptep_get((pte_t *)pmd);
+	if (pte_present(pte)) {
 		page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT);
 		if (flags & FOLL_GET)
 			get_page(page);
 	} else {
-		if (is_hugetlb_entry_migration(huge_ptep_get((pte_t *)pmd))) {
+		if (is_hugetlb_entry_migration(pte)) {
 			spin_unlock(ptl);
 			__migration_entry_wait(mm, (pte_t *)pmd, ptl);
 			goto retry;
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 1c260e6b3b3c..dd2dea8eb077 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -96,11 +96,6 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 		<< KASAN_SHADOW_SCALE_SHIFT);
 }
 
-static inline bool kasan_report_enabled(void)
-{
-	return !current->kasan_depth;
-}
-
 void kasan_report(unsigned long addr, size_t size,
 		bool is_write, unsigned long ip);
 void kasan_report_double_free(struct kmem_cache *cache, void *object,
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index f479365530b6..ab42a0803f16 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -13,7 +13,9 @@
  *
  */
 
+#include <linux/bitops.h>
 #include <linux/ftrace.h>
+#include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/printk.h>
@@ -293,6 +295,40 @@ static void kasan_report_error(struct kasan_access_info *info)
 	kasan_end_report(&flags);
 }
 
+static unsigned long kasan_flags;
+
+#define KASAN_BIT_REPORTED	0
+#define KASAN_BIT_MULTI_SHOT	1
+
+bool kasan_save_enable_multi_shot(void)
+{
+	return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
+}
+EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot);
+
+void kasan_restore_multi_shot(bool enabled)
+{
+	if (!enabled)
+		clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
+}
+EXPORT_SYMBOL_GPL(kasan_restore_multi_shot);
+
+static int __init kasan_set_multi_shot(char *str)
+{
+	set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
+	return 1;
+}
+__setup("kasan_multi_shot", kasan_set_multi_shot);
+
+static inline bool kasan_report_enabled(void)
+{
+	if (current->kasan_depth)
+		return false;
+	if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
+		return true;
+	return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);
+}
+
 void kasan_report(unsigned long addr, size_t size,
 		bool is_write, unsigned long ip)
 {
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 26c874e90b12..20036d4f9f13 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1416,7 +1416,7 @@ static void kmemleak_scan(void)
 	/* data/bss scanning */
 	scan_large_block(_sdata, _edata);
 	scan_large_block(__bss_start, __bss_stop);
-	scan_large_block(__start_data_ro_after_init, __end_data_ro_after_init);
+	scan_large_block(__start_ro_after_init, __end_ro_after_init);
 
 #ifdef CONFIG_SMP
 	/* per-cpu sections scanning */
diff --git a/mm/migrate.c b/mm/migrate.c
index 9a0897a14d37..ed97c2c14fa8 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -209,8 +209,11 @@ static int remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 
 	VM_BUG_ON_PAGE(PageTail(page), page);
 	while (page_vma_mapped_walk(&pvmw)) {
-		new = page - pvmw.page->index +
-			linear_page_index(vma, pvmw.address);
+		if (PageKsm(page))
+			new = page;
+		else
+			new = page - pvmw.page->index +
+				linear_page_index(vma, pvmw.address);
 
 		get_page(new);
 		pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot)));
diff --git a/mm/rmap.c b/mm/rmap.c
index 49ed681ccc7b..f6838015810f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1159,7 +1159,7 @@ void page_add_file_rmap(struct page *page, bool compound)
 			goto out;
 	}
 	__mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, nr);
-	mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
+	mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, nr);
 out:
 	unlock_page_memcg(page);
 }
@@ -1199,7 +1199,7 @@ static void page_remove_file_rmap(struct page *page, bool compound)
 	 * pte lock(a spinlock) is held, which implies preemption disabled.
 	 */
 	__mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, -nr);
-	mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
+	mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, -nr);
 
 	if (unlikely(PageMlocked(page)))
 		clear_page_mlock(page);
diff --git a/mm/vmstat.c b/mm/vmstat.c
index b1947f0cbee2..89f95396ec46 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1764,7 +1764,7 @@ static int vmstat_cpu_dead(unsigned int cpu)
 
 #endif
 
-static int __init setup_vmstat(void)
+void __init init_mm_internals(void)
 {
 #ifdef CONFIG_SMP
 	int ret;
@@ -1792,9 +1792,7 @@ static int __init setup_vmstat(void)
 	proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
 	proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
 #endif
-	return 0;
 }
-module_init(setup_vmstat)
 
 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
 
diff --git a/mm/workingset.c b/mm/workingset.c
index ac839fca0e76..eda05c71fa49 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -532,7 +532,7 @@ static int __init workingset_init(void)
 	pr_info("workingset: timestamp_bits=%d max_order=%d bucket_order=%u\n",
 	       timestamp_bits, max_order, bucket_order);
 
-	ret = list_lru_init_key(&shadow_nodes, &shadow_nodes_key);
+	ret = __list_lru_init(&shadow_nodes, true, &shadow_nodes_key);
 	if (ret)
 		goto err;
 	ret = register_shrinker(&workingset_shadow_shrinker);