Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "VM:
   - z3fold fixes and enhancements by Henry Burns and Vitaly Wool

   - more accurate reclaimed slab caches calculations by Yafang Shao

   - fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by
     Christoph Hellwig

   - !CONFIG_MMU fixes by Christoph Hellwig

   - new novmcoredd parameter to omit device dumps from vmcore, by
     Kairui Song

   - new test_meminit module for testing heap and pagealloc
     initialization, by Alexander Potapenko

   - ioremap improvements for huge mappings, by Anshuman Khandual

   - generalize kprobe page fault handling, by Anshuman Khandual

   - device-dax hotplug fixes and improvements, by Pavel Tatashin

   - enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V

   - add pte_devmap() support for arm64, by Robin Murphy

   - unify locked_vm accounting with a helper, by Daniel Jordan

   - several misc fixes

  core/lib:
   - new typeof_member() macro including some users, by Alexey Dobriyan

   - make BIT() and GENMASK() available in asm, by Masahiro Yamada

   - changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better
     code generation, by Alexey Dobriyan

   - rbtree code size optimizations, by Michel Lespinasse

   - convert struct pid count to refcount_t, by Joel Fernandes

  get_maintainer.pl:
   - add --no-moderated switch to skip moderated ML's, by Joe Perches

  misc:
   - ptrace PTRACE_GET_SYSCALL_INFO interface

   - coda updates

   - gdb scripts, various"

[ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ]

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits)
  fs/select.c: use struct_size() in kmalloc()
  mm: add account_locked_vm utility function
  arm64: mm: implement pte_devmap support
  mm: introduce ARCH_HAS_PTE_DEVMAP
  mm: clean up is_device_*_page() definitions
  mm/mmap: move common defines to mman-common.h
  mm: move MAP_SYNC to asm-generic/mman-common.h
  device-dax: "Hotremove" persistent memory that is used like normal RAM
  mm/hotplug: make remove_memory() interface usable
  device-dax: fix memory and resource leak if hotplug fails
  include/linux/lz4.h: fix spelling and copy-paste errors in documentation
  ipc/mqueue.c: only perform resource calculation if user valid
  include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures
  scripts/gdb: add helpers to find and list devices
  scripts/gdb: add lx-genpd-summary command
  drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl
  kernel/pid.c: convert struct pid count to refcount_t
  drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
  select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining()
  select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR
  ...

10 files changed, 531 insertions, 91 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index a858b55e8ac7..bc6673ab3a08 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2076,6 +2076,14 @@ config TEST_STACKINIT
 
 	  If unsure, say N.
 
+config TEST_MEMINIT
+	tristate "Test heap/page initialization"
+	help
+	  Test if the kernel is zero-initializing heap and page allocations.
+	  This can be useful to test init_on_alloc and init_on_free features.
+
+	  If unsure, say N.
+
 endif # RUNTIME_TESTING_MENU
 
 config MEMTEST
diff --git a/lib/Makefile b/lib/Makefile
index fdd56bc219b8..59067f51f3ab 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -92,6 +92,7 @@ obj-$(CONFIG_TEST_MEMCAT_P) += test_memcat_p.o
 obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o
 obj-$(CONFIG_TEST_STACKINIT) += test_stackinit.o
 obj-$(CONFIG_TEST_BLACKHOLE_DEV) += test_blackhole_dev.o
+obj-$(CONFIG_TEST_MEMINIT) += test_meminit.o
 
 obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/
 
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 063213685563..0a2ffadc6d71 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -30,6 +30,8 @@ early_param("nohugeiomap", set_nohugeiomap);
 void __init ioremap_huge_init(void)
 {
 	if (!ioremap_huge_disabled) {
+		if (arch_ioremap_p4d_supported())
+			ioremap_p4d_capable = 1;
 		if (arch_ioremap_pud_supported())
 			ioremap_pud_capable = 1;
 		if (arch_ioremap_pmd_supported())
@@ -86,6 +88,9 @@ static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr,
 	if ((end - addr) != PMD_SIZE)
 		return 0;
 
+	if (!IS_ALIGNED(addr, PMD_SIZE))
+		return 0;
+
 	if (!IS_ALIGNED(phys_addr, PMD_SIZE))
 		return 0;
 
@@ -126,6 +131,9 @@ static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr,
 	if ((end - addr) != PUD_SIZE)
 		return 0;
 
+	if (!IS_ALIGNED(addr, PUD_SIZE))
+		return 0;
+
 	if (!IS_ALIGNED(phys_addr, PUD_SIZE))
 		return 0;
 
@@ -166,6 +174,9 @@ static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
 	if ((end - addr) != P4D_SIZE)
 		return 0;
 
+	if (!IS_ALIGNED(addr, P4D_SIZE))
+		return 0;
+
 	if (!IS_ALIGNED(phys_addr, P4D_SIZE))
 		return 0;
 
diff --git a/lib/mpi/longlong.h b/lib/mpi/longlong.h
index 08c60d10747f..3bb6260d8f42 100644
--- a/lib/mpi/longlong.h
+++ b/lib/mpi/longlong.h
@@ -397,8 +397,8 @@ do { \
 #define add_ssaaaa(sh, sl, ah, al, bh, bl) \
 	__asm__ ("addl %5,%1\n" \
 	   "adcl %3,%0" \
-	: "=r" ((USItype)(sh)), \
-	     "=&r" ((USItype)(sl)) \
+	: "=r" (sh), \
+	     "=&r" (sl) \
 	: "%0" ((USItype)(ah)), \
 	     "g" ((USItype)(bh)), \
 	     "%1" ((USItype)(al)), \
@@ -406,22 +406,22 @@ do { \
 #define sub_ddmmss(sh, sl, ah, al, bh, bl) \
 	__asm__ ("subl %5,%1\n" \
 	   "sbbl %3,%0" \
-	: "=r" ((USItype)(sh)), \
-	     "=&r" ((USItype)(sl)) \
+	: "=r" (sh), \
+	     "=&r" (sl) \
 	: "0" ((USItype)(ah)), \
 	     "g" ((USItype)(bh)), \
 	     "1" ((USItype)(al)), \
 	     "g" ((USItype)(bl)))
 #define umul_ppmm(w1, w0, u, v) \
 	__asm__ ("mull %3" \
-	: "=a" ((USItype)(w0)), \
-	     "=d" ((USItype)(w1)) \
+	: "=a" (w0), \
+	     "=d" (w1) \
 	: "%0" ((USItype)(u)), \
 	     "rm" ((USItype)(v)))
 #define udiv_qrnnd(q, r, n1, n0, d) \
 	__asm__ ("divl %4" \
-	: "=a" ((USItype)(q)), \
-	     "=d" ((USItype)(r)) \
+	: "=a" (q), \
+	     "=d" (r) \
 	: "0" ((USItype)(n0)), \
 	     "1" ((USItype)(n1)), \
 	     "rm" ((USItype)(d)))
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 1ef6e25d031c..abc86c6a3177 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -83,14 +83,10 @@ __rb_rotate_set_parents(struct rb_node *old, struct rb_node *new,
 
 static __always_inline void
 __rb_insert(struct rb_node *node, struct rb_root *root,
-	    bool newleft, struct rb_node **leftmost,
 	    void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
 {
 	struct rb_node *parent = rb_red_parent(node), *gparent, *tmp;
 
-	if (newleft)
-		*leftmost = node;
-
 	while (true) {
 		/*
 		 * Loop invariant: node is red.
@@ -437,38 +433,19 @@ static const struct rb_augment_callbacks dummy_callbacks = {
 
 void rb_insert_color(struct rb_node *node, struct rb_root *root)
 {
-	__rb_insert(node, root, false, NULL, dummy_rotate);
+	__rb_insert(node, root, dummy_rotate);
 }
 EXPORT_SYMBOL(rb_insert_color);
 
 void rb_erase(struct rb_node *node, struct rb_root *root)
 {
 	struct rb_node *rebalance;
-	rebalance = __rb_erase_augmented(node, root,
-					 NULL, &dummy_callbacks);
+	rebalance = __rb_erase_augmented(node, root, &dummy_callbacks);
 	if (rebalance)
 		____rb_erase_color(rebalance, root, dummy_rotate);
 }
 EXPORT_SYMBOL(rb_erase);
 
-void rb_insert_color_cached(struct rb_node *node,
-			    struct rb_root_cached *root, bool leftmost)
-{
-	__rb_insert(node, &root->rb_root, leftmost,
-		    &root->rb_leftmost, dummy_rotate);
-}
-EXPORT_SYMBOL(rb_insert_color_cached);
-
-void rb_erase_cached(struct rb_node *node, struct rb_root_cached *root)
-{
-	struct rb_node *rebalance;
-	rebalance = __rb_erase_augmented(node, &root->rb_root,
-					 &root->rb_leftmost, &dummy_callbacks);
-	if (rebalance)
-		____rb_erase_color(rebalance, &root->rb_root, dummy_rotate);
-}
-EXPORT_SYMBOL(rb_erase_cached);
-
 /*
  * Augmented rbtree manipulation functions.
  *
@@ -477,10 +454,9 @@ EXPORT_SYMBOL(rb_erase_cached);
  */
 
 void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
-			   bool newleft, struct rb_node **leftmost,
 	void (*augment_rotate)(struct rb_node *old, struct rb_node *new))
 {
-	__rb_insert(node, root, newleft, leftmost, augment_rotate);
+	__rb_insert(node, root, augment_rotate);
 }
 EXPORT_SYMBOL(__rb_insert_augmented);
 
@@ -591,16 +567,6 @@ void rb_replace_node(struct rb_node *victim, struct rb_node *new,
 }
 EXPORT_SYMBOL(rb_replace_node);
 
-void rb_replace_node_cached(struct rb_node *victim, struct rb_node *new,
-			    struct rb_root_cached *root)
-{
-	rb_replace_node(victim, new, &root->rb_root);
-
-	if (root->rb_leftmost == victim)
-		root->rb_leftmost = new;
-}
-EXPORT_SYMBOL(rb_replace_node_cached);
-
 void rb_replace_node_rcu(struct rb_node *victim, struct rb_node *new,
 			 struct rb_root *root)
 {
diff --git a/lib/string.c b/lib/string.c
index 6016eb3ac73d..461fb620f85f 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -400,6 +400,9 @@ EXPORT_SYMBOL(strncmp);
  * strchr - Find the first occurrence of a character in a string
  * @s: The string to be searched
  * @c: The character to search for
+ *
+ * Note that the %NUL-terminator is considered part of the string, and can
+ * be searched for.
  */
 char *strchr(const char *s, int c)
 {
@@ -453,12 +456,18 @@ EXPORT_SYMBOL(strrchr);
  * @s: The string to be searched
  * @count: The number of characters to be searched
  * @c: The character to search for
+ *
+ * Note that the %NUL-terminator is considered part of the string, and can
+ * be searched for.
  */
 char *strnchr(const char *s, size_t count, int c)
 {
-	for (; count-- && *s != '\0'; ++s)
+	while (count--) {
 		if (*s == (char)c)
 			return (char *)s;
+		if (*s++ == '\0')
+			break;
+	}
 	return NULL;
 }
 EXPORT_SYMBOL(strnchr);
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 3a90a9e2b94a..963050c0283e 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -231,35 +231,36 @@ static bool unescape_special(char **src, char **dst)
  * @src:	source buffer (escaped)
  * @dst:	destination buffer (unescaped)
  * @size:	size of the destination buffer (0 to unlimit)
- * @flags:	combination of the flags (bitwise OR):
- *	%UNESCAPE_SPACE:
+ * @flags:	combination of the flags.
+ *
+ * Description:
+ * The function unquotes characters in the given string.
+ *
+ * Because the size of the output will be the same as or less than the size of
+ * the input, the transformation may be performed in place.
+ *
+ * Caller must provide valid source and destination pointers. Be aware that
+ * destination buffer will always be NULL-terminated. Source string must be
+ * NULL-terminated as well.  The supported flags are::
+ *
+ *	UNESCAPE_SPACE:
  *		'\f' - form feed
  *		'\n' - new line
  *		'\r' - carriage return
  *		'\t' - horizontal tab
  *		'\v' - vertical tab
- *	%UNESCAPE_OCTAL:
+ *	UNESCAPE_OCTAL:
  *		'\NNN' - byte with octal value NNN (1 to 3 digits)
- *	%UNESCAPE_HEX:
+ *	UNESCAPE_HEX:
  *		'\xHH' - byte with hexadecimal value HH (1 to 2 digits)
- *	%UNESCAPE_SPECIAL:
+ *	UNESCAPE_SPECIAL:
  *		'\"' - double quote
  *		'\\' - backslash
  *		'\a' - alert (BEL)
  *		'\e' - escape
- *	%UNESCAPE_ANY:
+ *	UNESCAPE_ANY:
  *		all previous together
  *
- * Description:
- * The function unquotes characters in the given string.
- *
- * Because the size of the output will be the same as or less than the size of
- * the input, the transformation may be performed in place.
- *
- * Caller must provide valid source and destination pointers. Be aware that
- * destination buffer will always be NULL-terminated. Source string must be
- * NULL-terminated as well.
- *
  * Return:
  * The amount of the characters processed to the destination buffer excluding
  * trailing '\0' is returned.
@@ -441,7 +442,29 @@ static bool escape_hex(unsigned char c, char **dst, char *end)
  * @isz:	source buffer size
  * @dst:	destination buffer (escaped)
  * @osz:	destination buffer size
- * @flags:	combination of the flags (bitwise OR):
+ * @flags:	combination of the flags
+ * @only:	NULL-terminated string containing characters used to limit
+ *		the selected escape class. If characters are included in @only
+ *		that would not normally be escaped by the classes selected
+ *		in @flags, they will be copied to @dst unescaped.
+ *
+ * Description:
+ * The process of escaping byte buffer includes several parts. They are applied
+ * in the following sequence.
+ *
+ *	1. The character is matched to the printable class, if asked, and in
+ *	   case of match it passes through to the output.
+ *	2. The character is not matched to the one from @only string and thus
+ *	   must go as-is to the output.
+ *	3. The character is checked if it falls into the class given by @flags.
+ *	   %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
+ *	   character. Note that they actually can't go together, otherwise
+ *	   %ESCAPE_HEX will be ignored.
+ *
+ * Caller must provide valid source and destination pointers. Be aware that
+ * destination buffer will not be NULL-terminated, thus caller have to append
+ * it if needs.   The supported flags are::
+ *
  *	%ESCAPE_SPACE: (special white space, not space itself)
  *		'\f' - form feed
  *		'\n' - new line
@@ -464,26 +487,6 @@ static bool escape_hex(unsigned char c, char **dst, char *end)
  *		all previous together
  *	%ESCAPE_HEX:
  *		'\xHH' - byte with hexadecimal value HH (2 digits)
- * @only:	NULL-terminated string containing characters used to limit
- *		the selected escape class. If characters are included in @only
- *		that would not normally be escaped by the classes selected
- *		in @flags, they will be copied to @dst unescaped.
- *
- * Description:
- * The process of escaping byte buffer includes several parts. They are applied
- * in the following sequence.
- *	1. The character is matched to the printable class, if asked, and in
- *	   case of match it passes through to the output.
- *	2. The character is not matched to the one from @only string and thus
- *	   must go as-is to the output.
- *	3. The character is checked if it falls into the class given by @flags.
- *	   %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
- *	   character. Note that they actually can't go together, otherwise
- *	   %ESCAPE_HEX will be ignored.
- *
- * Caller must provide valid source and destination pointers. Be aware that
- * destination buffer will not be NULL-terminated, thus caller have to append
- * it if needs.
  *
  * Return:
  * The total size of the escaped output that would be generated for
diff --git a/lib/test_meminit.c b/lib/test_meminit.c
new file mode 100644
index 000000000000..62d19f270cad
--- /dev/null
+++ b/lib/test_meminit.c
@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for SL[AOU]B/page initialization at alloc/free time.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+
+#define GARBAGE_INT (0x09A7BA9E)
+#define GARBAGE_BYTE (0x9E)
+
+#define REPORT_FAILURES_IN_FN() \
+	do {	\
+		if (failures)	\
+			pr_info("%s failed %d out of %d times\n",	\
+				__func__, failures, num_tests);		\
+		else		\
+			pr_info("all %d tests in %s passed\n",		\
+				num_tests, __func__);			\
+	} while (0)
+
+/* Calculate the number of uninitialized bytes in the buffer. */
+static int __init count_nonzero_bytes(void *ptr, size_t size)
+{
+	int i, ret = 0;
+	unsigned char *p = (unsigned char *)ptr;
+
+	for (i = 0; i < size; i++)
+		if (p[i])
+			ret++;
+	return ret;
+}
+
+/* Fill a buffer with garbage, skipping |skip| first bytes. */
+static void __init fill_with_garbage_skip(void *ptr, int size, size_t skip)
+{
+	unsigned int *p = (unsigned int *)((char *)ptr + skip);
+	int i = 0;
+
+	WARN_ON(skip > size);
+	size -= skip;
+
+	while (size >= sizeof(*p)) {
+		p[i] = GARBAGE_INT;
+		i++;
+		size -= sizeof(*p);
+	}
+	if (size)
+		memset(&p[i], GARBAGE_BYTE, size);
+}
+
+static void __init fill_with_garbage(void *ptr, size_t size)
+{
+	fill_with_garbage_skip(ptr, size, 0);
+}
+
+static int __init do_alloc_pages_order(int order, int *total_failures)
+{
+	struct page *page;
+	void *buf;
+	size_t size = PAGE_SIZE << order;
+
+	page = alloc_pages(GFP_KERNEL, order);
+	buf = page_address(page);
+	fill_with_garbage(buf, size);
+	__free_pages(page, order);
+
+	page = alloc_pages(GFP_KERNEL, order);
+	buf = page_address(page);
+	if (count_nonzero_bytes(buf, size))
+		(*total_failures)++;
+	fill_with_garbage(buf, size);
+	__free_pages(page, order);
+	return 1;
+}
+
+/* Test the page allocator by calling alloc_pages with different orders. */
+static int __init test_pages(int *total_failures)
+{
+	int failures = 0, num_tests = 0;
+	int i;
+
+	for (i = 0; i < 10; i++)
+		num_tests += do_alloc_pages_order(i, &failures);
+
+	REPORT_FAILURES_IN_FN();
+	*total_failures += failures;
+	return num_tests;
+}
+
+/* Test kmalloc() with given parameters. */
+static int __init do_kmalloc_size(size_t size, int *total_failures)
+{
+	void *buf;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	fill_with_garbage(buf, size);
+	kfree(buf);
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (count_nonzero_bytes(buf, size))
+		(*total_failures)++;
+	fill_with_garbage(buf, size);
+	kfree(buf);
+	return 1;
+}
+
+/* Test vmalloc() with given parameters. */
+static int __init do_vmalloc_size(size_t size, int *total_failures)
+{
+	void *buf;
+
+	buf = vmalloc(size);
+	fill_with_garbage(buf, size);
+	vfree(buf);
+
+	buf = vmalloc(size);
+	if (count_nonzero_bytes(buf, size))
+		(*total_failures)++;
+	fill_with_garbage(buf, size);
+	vfree(buf);
+	return 1;
+}
+
+/* Test kmalloc()/vmalloc() by allocating objects of different sizes. */
+static int __init test_kvmalloc(int *total_failures)
+{
+	int failures = 0, num_tests = 0;
+	int i, size;
+
+	for (i = 0; i < 20; i++) {
+		size = 1 << i;
+		num_tests += do_kmalloc_size(size, &failures);
+		num_tests += do_vmalloc_size(size, &failures);
+	}
+
+	REPORT_FAILURES_IN_FN();
+	*total_failures += failures;
+	return num_tests;
+}
+
+#define CTOR_BYTES (sizeof(unsigned int))
+#define CTOR_PATTERN (0x41414141)
+/* Initialize the first 4 bytes of the object. */
+static void test_ctor(void *obj)
+{
+	*(unsigned int *)obj = CTOR_PATTERN;
+}
+
+/*
+ * Check the invariants for the buffer allocated from a slab cache.
+ * If the cache has a test constructor, the first 4 bytes of the object must
+ * always remain equal to CTOR_PATTERN.
+ * If the cache isn't an RCU-typesafe one, or if the allocation is done with
+ * __GFP_ZERO, then the object contents must be zeroed after allocation.
+ * If the cache is an RCU-typesafe one, the object contents must never be
+ * zeroed after the first use. This is checked by memcmp() in
+ * do_kmem_cache_size().
+ */
+static bool __init check_buf(void *buf, int size, bool want_ctor,
+			     bool want_rcu, bool want_zero)
+{
+	int bytes;
+	bool fail = false;
+
+	bytes = count_nonzero_bytes(buf, size);
+	WARN_ON(want_ctor && want_zero);
+	if (want_zero)
+		return bytes;
+	if (want_ctor) {
+		if (*(unsigned int *)buf != CTOR_PATTERN)
+			fail = 1;
+	} else {
+		if (bytes)
+			fail = !want_rcu;
+	}
+	return fail;
+}
+
+/*
+ * Test kmem_cache with given parameters:
+ *  want_ctor - use a constructor;
+ *  want_rcu - use SLAB_TYPESAFE_BY_RCU;
+ *  want_zero - use __GFP_ZERO.
+ */
+static int __init do_kmem_cache_size(size_t size, bool want_ctor,
+				     bool want_rcu, bool want_zero,
+				     int *total_failures)
+{
+	struct kmem_cache *c;
+	int iter;
+	bool fail = false;
+	gfp_t alloc_mask = GFP_KERNEL | (want_zero ? __GFP_ZERO : 0);
+	void *buf, *buf_copy;
+
+	c = kmem_cache_create("test_cache", size, 1,
+			      want_rcu ? SLAB_TYPESAFE_BY_RCU : 0,
+			      want_ctor ? test_ctor : NULL);
+	for (iter = 0; iter < 10; iter++) {
+		buf = kmem_cache_alloc(c, alloc_mask);
+		/* Check that buf is zeroed, if it must be. */
+		fail = check_buf(buf, size, want_ctor, want_rcu, want_zero);
+		fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);
+
+		if (!want_rcu) {
+			kmem_cache_free(c, buf);
+			continue;
+		}
+
+		/*
+		 * If this is an RCU cache, use a critical section to ensure we
+		 * can touch objects after they're freed.
+		 */
+		rcu_read_lock();
+		/*
+		 * Copy the buffer to check that it's not wiped on
+		 * free().
+		 */
+		buf_copy = kmalloc(size, GFP_KERNEL);
+		if (buf_copy)
+			memcpy(buf_copy, buf, size);
+
+		kmem_cache_free(c, buf);
+		/*
+		 * Check that |buf| is intact after kmem_cache_free().
+		 * |want_zero| is false, because we wrote garbage to
+		 * the buffer already.
+		 */
+		fail |= check_buf(buf, size, want_ctor, want_rcu,
+				  false);
+		if (buf_copy) {
+			fail |= (bool)memcmp(buf, buf_copy, size);
+			kfree(buf_copy);
+		}
+		rcu_read_unlock();
+	}
+	kmem_cache_destroy(c);
+
+	*total_failures += fail;
+	return 1;
+}
+
+/*
+ * Check that the data written to an RCU-allocated object survives
+ * reallocation.
+ */
+static int __init do_kmem_cache_rcu_persistent(int size, int *total_failures)
+{
+	struct kmem_cache *c;
+	void *buf, *buf_contents, *saved_ptr;
+	void **used_objects;
+	int i, iter, maxiter = 1024;
+	bool fail = false;
+
+	c = kmem_cache_create("test_cache", size, size, SLAB_TYPESAFE_BY_RCU,
+			      NULL);
+	buf = kmem_cache_alloc(c, GFP_KERNEL);
+	saved_ptr = buf;
+	fill_with_garbage(buf, size);
+	buf_contents = kmalloc(size, GFP_KERNEL);
+	if (!buf_contents)
+		goto out;
+	used_objects = kmalloc_array(maxiter, sizeof(void *), GFP_KERNEL);
+	if (!used_objects) {
+		kfree(buf_contents);
+		goto out;
+	}
+	memcpy(buf_contents, buf, size);
+	kmem_cache_free(c, buf);
+	/*
+	 * Run for a fixed number of iterations. If we never hit saved_ptr,
+	 * assume the test passes.
+	 */
+	for (iter = 0; iter < maxiter; iter++) {
+		buf = kmem_cache_alloc(c, GFP_KERNEL);
+		used_objects[iter] = buf;
+		if (buf == saved_ptr) {
+			fail = memcmp(buf_contents, buf, size);
+			for (i = 0; i <= iter; i++)
+				kmem_cache_free(c, used_objects[i]);
+			goto free_out;
+		}
+	}
+
+free_out:
+	kmem_cache_destroy(c);
+	kfree(buf_contents);
+	kfree(used_objects);
+out:
+	*total_failures += fail;
+	return 1;
+}
+
+/*
+ * Test kmem_cache allocation by creating caches of different sizes, with and
+ * without constructors, with and without SLAB_TYPESAFE_BY_RCU.
+ */
+static int __init test_kmemcache(int *total_failures)
+{
+	int failures = 0, num_tests = 0;
+	int i, flags, size;
+	bool ctor, rcu, zero;
+
+	for (i = 0; i < 10; i++) {
+		size = 8 << i;
+		for (flags = 0; flags < 8; flags++) {
+			ctor = flags & 1;
+			rcu = flags & 2;
+			zero = flags & 4;
+			if (ctor & zero)
+				continue;
+			num_tests += do_kmem_cache_size(size, ctor, rcu, zero,
+							&failures);
+		}
+	}
+	REPORT_FAILURES_IN_FN();
+	*total_failures += failures;
+	return num_tests;
+}
+
+/* Test the behavior of SLAB_TYPESAFE_BY_RCU caches of different sizes. */
+static int __init test_rcu_persistent(int *total_failures)
+{
+	int failures = 0, num_tests = 0;
+	int i, size;
+
+	for (i = 0; i < 10; i++) {
+		size = 8 << i;
+		num_tests += do_kmem_cache_rcu_persistent(size, &failures);
+	}
+	REPORT_FAILURES_IN_FN();
+	*total_failures += failures;
+	return num_tests;
+}
+
+/*
+ * Run the tests. Each test function returns the number of executed tests and
+ * updates |failures| with the number of failed tests.
+ */
+static int __init test_meminit_init(void)
+{
+	int failures = 0, num_tests = 0;
+
+	num_tests += test_pages(&failures);
+	num_tests += test_kvmalloc(&failures);
+	num_tests += test_kmemcache(&failures);
+	num_tests += test_rcu_persistent(&failures);
+
+	if (failures == 0)
+		pr_info("all %d tests passed!\n", num_tests);
+	else
+		pr_info("failures: %d out of %d\n", failures, num_tests);
+
+	return failures ? -EINVAL : 0;
+}
+module_init(test_meminit_init);
+
+MODULE_LICENSE("GPL");
diff --git a/lib/test_overflow.c b/lib/test_overflow.c
index fc680562d8b6..7a4b6f6c5473 100644
--- a/lib/test_overflow.c
+++ b/lib/test_overflow.c
@@ -486,16 +486,17 @@ static int __init test_overflow_shift(void)
  * Deal with the various forms of allocator arguments. See comments above
  * the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
  */
-#define alloc010(alloc, arg, sz) alloc(sz, GFP_KERNEL)
-#define alloc011(alloc, arg, sz) alloc(sz, GFP_KERNEL, NUMA_NO_NODE)
+#define alloc_GFP		 (GFP_KERNEL | __GFP_NOWARN)
+#define alloc010(alloc, arg, sz) alloc(sz, alloc_GFP)
+#define alloc011(alloc, arg, sz) alloc(sz, alloc_GFP, NUMA_NO_NODE)
 #define alloc000(alloc, arg, sz) alloc(sz)
 #define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
-#define alloc110(alloc, arg, sz) alloc(arg, sz, GFP_KERNEL)
+#define alloc110(alloc, arg, sz) alloc(arg, sz, alloc_GFP)
 #define free0(free, arg, ptr)	 free(ptr)
 #define free1(free, arg, ptr)	 free(arg, ptr)
 
-/* Wrap around to 8K */
-#define TEST_SIZE		(9 << PAGE_SHIFT)
+/* Wrap around to 16K */
+#define TEST_SIZE		(5 * 4096)
 
 #define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
 static int __init test_ ## func (void *arg)				\
diff --git a/lib/test_string.c b/lib/test_string.c
index bf8def01ed20..7b31f4a505bf 100644
--- a/lib/test_string.c
+++ b/lib/test_string.c
@@ -36,7 +36,7 @@ static __init int memset16_selftest(void)
 fail:
 	kfree(p);
 	if (i < 256)
-		return (i << 24) | (j << 16) | k;
+		return (i << 24) | (j << 16) | k | 0x8000;
 	return 0;
 }
 
@@ -72,7 +72,7 @@ static __init int memset32_selftest(void)
 fail:
 	kfree(p);
 	if (i < 256)
-		return (i << 24) | (j << 16) | k;
+		return (i << 24) | (j << 16) | k | 0x8000;
 	return 0;
 }
 
@@ -108,7 +108,74 @@ static __init int memset64_selftest(void)
 fail:
 	kfree(p);
 	if (i < 256)
-		return (i << 24) | (j << 16) | k;
+		return (i << 24) | (j << 16) | k | 0x8000;
+	return 0;
+}
+
+static __init int strchr_selftest(void)
+{
+	const char *test_string = "abcdefghijkl";
+	const char *empty_string = "";
+	char *result;
+	int i;
+
+	for (i = 0; i < strlen(test_string) + 1; i++) {
+		result = strchr(test_string, test_string[i]);
+		if (result - test_string != i)
+			return i + 'a';
+	}
+
+	result = strchr(empty_string, '\0');
+	if (result != empty_string)
+		return 0x101;
+
+	result = strchr(empty_string, 'a');
+	if (result)
+		return 0x102;
+
+	result = strchr(test_string, 'z');
+	if (result)
+		return 0x103;
+
+	return 0;
+}
+
+static __init int strnchr_selftest(void)
+{
+	const char *test_string = "abcdefghijkl";
+	const char *empty_string = "";
+	char *result;
+	int i, j;
+
+	for (i = 0; i < strlen(test_string) + 1; i++) {
+		for (j = 0; j < strlen(test_string) + 2; j++) {
+			result = strnchr(test_string, j, test_string[i]);
+			if (j <= i) {
+				if (!result)
+					continue;
+				return ((i + 'a') << 8) | j;
+			}
+			if (result - test_string != i)
+				return ((i + 'a') << 8) | j;
+		}
+	}
+
+	result = strnchr(empty_string, 0, '\0');
+	if (result)
+		return 0x10001;
+
+	result = strnchr(empty_string, 1, '\0');
+	if (result != empty_string)
+		return 0x10002;
+
+	result = strnchr(empty_string, 1, 'a');
+	if (result)
+		return 0x10003;
+
+	result = strnchr(NULL, 0, '\0');
+	if (result)
+		return 0x10004;
+
 	return 0;
 }
 
@@ -131,6 +198,16 @@ static __init int string_selftest_init(void)
 	if (subtest)
 		goto fail;
 
+	test = 4;
+	subtest = strchr_selftest();
+	if (subtest)
+		goto fail;
+
+	test = 5;
+	subtest = strnchr_selftest();
+	if (subtest)
+		goto fail;
+
 	pr_info("String selftests succeeded\n");
 	return 0;
 fail: