Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - a bit more MM

 - procfs updates

 - dynamic-debug fixes

 - lib/ updates

 - checkpatch

 - epoll

 - nilfs2

 - signals

 - rapidio

 - PID management cleanup and optimization

 - kcov updates

 - sysvipc updates

 - quite a few misc things all over the place

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
  EXPERT Kconfig menu: fix broken EXPERT menu
  include/asm-generic/topology.h: remove unused parent_node() macro
  arch/tile/include/asm/topology.h: remove unused parent_node() macro
  arch/sparc/include/asm/topology_64.h: remove unused parent_node() macro
  arch/sh/include/asm/topology.h: remove unused parent_node() macro
  arch/ia64/include/asm/topology.h: remove unused parent_node() macro
  drivers/pcmcia/sa1111_badge4.c: avoid unused function warning
  mm: add infrastructure for get_user_pages_fast() benchmarking
  sysvipc: make get_maxid O(1) again
  sysvipc: properly name ipc_addid() limit parameter
  sysvipc: duplicate lock comments wrt ipc_addid()
  sysvipc: unteach ids->next_id for !CHECKPOINT_RESTORE
  initramfs: use time64_t timestamps
  drivers/watchdog: make use of devm_register_reboot_notifier()
  kernel/reboot.c: add devm_register_reboot_notifier()
  kcov: update documentation
  Makefile: support flag -fsanitizer-coverage=trace-cmp
  kcov: support comparison operands collection
  kcov: remove pointless current != NULL check
  kernel/panic.c: add TAINT_AUX
  ...

17 files changed, 374 insertions, 173 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index a2b6745324ab..368972f0db78 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -584,7 +584,7 @@ config PRIME_NUMBERS
 	tristate
 
 config STRING_SELFTEST
-	bool "Test string functions"
+	tristate "Test string functions"
 
 endmenu
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 8ffd891857ab..947d3e2ed5c2 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -756,6 +756,16 @@ config KCOV
 
 	  For more details, see Documentation/dev-tools/kcov.rst.
 
+config KCOV_ENABLE_COMPARISONS
+	bool "Enable comparison operands collection by KCOV"
+	depends on KCOV
+	default n
+	help
+	  KCOV also exposes operands of every comparison in the instrumented
+	  code along with operand sizes and PCs of the comparison instructions.
+	  These operands can be used by fuzzing engines to improve the quality
+	  of fuzzing coverage.
+
 config KCOV_INSTRUMENT_ALL
 	bool "Instrument all code by default"
 	depends on KCOV
@@ -1850,6 +1860,15 @@ config TEST_BPF
 
 	  If unsure, say N.
 
+config TEST_FIND_BIT
+	tristate "Test find_bit functions"
+	default n
+	help
+	  This builds the "test_find_bit" module that measure find_*_bit()
+	  functions performance.
+
+	  If unsure, say N.
+
 config TEST_FIRMWARE
 	tristate "Test firmware loading via userspace interface"
 	default n
diff --git a/lib/Makefile b/lib/Makefile
index 136a0b254564..d11c48ec8ffd 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -40,12 +40,14 @@ obj-y += bcd.o div64.o sort.o parser.o debug_locks.o random32.o \
 	 bsearch.o find_bit.o llist.o memweight.o kfifo.o \
 	 percpu-refcount.o percpu_ida.o rhashtable.o reciprocal_div.o \
 	 once.o refcount.o usercopy.o errseq.o
+obj-$(CONFIG_STRING_SELFTEST) += test_string.o
 obj-y += string_helpers.o
 obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
 obj-y += hexdump.o
 obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o
 obj-y += kstrtox.o
 obj-$(CONFIG_TEST_BPF) += test_bpf.o
+obj-$(CONFIG_TEST_FIND_BIT) += test_find_bit.o
 obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
 obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o
 obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o
diff --git a/lib/bug.c b/lib/bug.c
index 1e094408c893..c1b0fad31b10 100644
--- a/lib/bug.c
+++ b/lib/bug.c
@@ -186,7 +186,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
 		return BUG_TRAP_TYPE_WARN;
 	}
 
-	printk(KERN_DEFAULT "------------[ cut here ]------------\n");
+	printk(KERN_DEFAULT CUT_HERE);
 
 	if (file)
 		pr_crit("kernel BUG at %s:%u!\n", file, line);
@@ -196,3 +196,26 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
 
 	return BUG_TRAP_TYPE_BUG;
 }
+
+static void clear_once_table(struct bug_entry *start, struct bug_entry *end)
+{
+	struct bug_entry *bug;
+
+	for (bug = start; bug < end; bug++)
+		bug->flags &= ~BUGFLAG_DONE;
+}
+
+void generic_bug_clear_once(void)
+{
+#ifdef CONFIG_MODULES
+	struct module *mod;
+
+	rcu_read_lock_sched();
+	list_for_each_entry_rcu(mod, &module_bug_list, bug_list)
+		clear_once_table(mod->bug_table,
+				 mod->bug_table + mod->num_bugs);
+	rcu_read_unlock_sched();
+#endif
+
+	clear_once_table(__start___bug_table, __stop___bug_table);
+}
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index ea4cc3dde4f1..1b34d210452c 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1495,14 +1495,22 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size,
 	if (!entry)
 		return;
 
+	/* handle vmalloc and linear addresses */
+	if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
+		return;
+
 	entry->type      = dma_debug_coherent;
 	entry->dev       = dev;
-	entry->pfn	 = page_to_pfn(virt_to_page(virt));
 	entry->offset	 = offset_in_page(virt);
 	entry->size      = size;
 	entry->dev_addr  = dma_addr;
 	entry->direction = DMA_BIDIRECTIONAL;
 
+	if (is_vmalloc_addr(virt))
+		entry->pfn = vmalloc_to_pfn(virt);
+	else
+		entry->pfn = page_to_pfn(virt_to_page(virt));
+
 	add_dma_entry(entry);
 }
 EXPORT_SYMBOL(debug_dma_alloc_coherent);
@@ -1513,13 +1521,21 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
 	struct dma_debug_entry ref = {
 		.type           = dma_debug_coherent,
 		.dev            = dev,
-		.pfn		= page_to_pfn(virt_to_page(virt)),
 		.offset		= offset_in_page(virt),
 		.dev_addr       = addr,
 		.size           = size,
 		.direction      = DMA_BIDIRECTIONAL,
 	};
 
+	/* handle vmalloc and linear addresses */
+	if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
+		return;
+
+	if (is_vmalloc_addr(virt))
+		ref.pfn = vmalloc_to_pfn(virt);
+	else
+		ref.pfn = page_to_pfn(virt_to_page(virt));
+
 	if (unlikely(dma_debug_disabled()))
 		return;
 
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index da796e2dc4f5..c7c96bc7654a 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -360,6 +360,10 @@ static int ddebug_parse_query(char *words[], int nwords,
 				if (parse_lineno(last, &query->last_lineno) < 0)
 					return -EINVAL;
 
+				/* special case for last lineno not specified */
+				if (query->last_lineno == 0)
+					query->last_lineno = UINT_MAX;
+
 				if (query->last_lineno < query->first_lineno) {
 					pr_err("last-line:%d < 1st-line:%d\n",
 						query->last_lineno,
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 144fe6b1a03e..ca06adc4f445 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -194,7 +194,7 @@ int gen_pool_add_virt(struct gen_pool *pool, unsigned long virt, phys_addr_t phy
 	chunk->phys_addr = phys;
 	chunk->start_addr = virt;
 	chunk->end_addr = virt + size - 1;
-	atomic_set(&chunk->avail, size);
+	atomic_long_set(&chunk->avail, size);
 
 	spin_lock(&pool->lock);
 	list_add_rcu(&chunk->next_chunk, &pool->chunks);
@@ -304,7 +304,7 @@ unsigned long gen_pool_alloc_algo(struct gen_pool *pool, size_t size,
 	nbits = (size + (1UL << order) - 1) >> order;
 	rcu_read_lock();
 	list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
-		if (size > atomic_read(&chunk->avail))
+		if (size > atomic_long_read(&chunk->avail))
 			continue;
 
 		start_bit = 0;
@@ -324,7 +324,7 @@ retry:
 
 		addr = chunk->start_addr + ((unsigned long)start_bit << order);
 		size = nbits << order;
-		atomic_sub(size, &chunk->avail);
+		atomic_long_sub(size, &chunk->avail);
 		break;
 	}
 	rcu_read_unlock();
@@ -390,7 +390,7 @@ void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
 			remain = bitmap_clear_ll(chunk->bits, start_bit, nbits);
 			BUG_ON(remain);
 			size = nbits << order;
-			atomic_add(size, &chunk->avail);
+			atomic_long_add(size, &chunk->avail);
 			rcu_read_unlock();
 			return;
 		}
@@ -464,7 +464,7 @@ size_t gen_pool_avail(struct gen_pool *pool)
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk)
-		avail += atomic_read(&chunk->avail);
+		avail += atomic_long_read(&chunk->avail);
 	rcu_read_unlock();
 	return avail;
 }
diff --git a/lib/int_sqrt.c b/lib/int_sqrt.c
index db0b5aa071fc..e2d329099bf7 100644
--- a/lib/int_sqrt.c
+++ b/lib/int_sqrt.c
@@ -8,12 +8,13 @@
 
 #include <linux/kernel.h>
 #include <linux/export.h>
+#include <linux/bitops.h>
 
 /**
- * int_sqrt - rough approximation to sqrt
+ * int_sqrt - computes the integer square root
  * @x: integer of which to calculate the sqrt
  *
- * A very rough approximation to the sqrt() function.
+ * Computes: floor(sqrt(x))
  */
 unsigned long int_sqrt(unsigned long x)
 {
@@ -22,7 +23,7 @@ unsigned long int_sqrt(unsigned long x)
 	if (x <= 1)
 		return x;
 
-	m = 1UL << (BITS_PER_LONG - 2);
+	m = 1UL << (__fls(x) & ~1UL);
 	while (m != 0) {
 		b = y + m;
 		y >>= 1;
diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
index 0e343fd29570..835242e74aaa 100644
--- a/lib/interval_tree_test.c
+++ b/lib/interval_tree_test.c
@@ -11,10 +11,10 @@
 	MODULE_PARM_DESC(name, msg);
 
 __param(int, nnodes, 100, "Number of nodes in the interval tree");
-__param(int, perf_loops, 100000, "Number of iterations modifying the tree");
+__param(int, perf_loops, 1000, "Number of iterations modifying the tree");
 
 __param(int, nsearches, 100, "Number of searches to the interval tree");
-__param(int, search_loops, 10000, "Number of iterations searching the tree");
+__param(int, search_loops, 1000, "Number of iterations searching the tree");
 __param(bool, search_all, false, "Searches will iterate all nodes in the tree");
 
 __param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
index 46e4c749e4eb..61a6b5aab07e 100644
--- a/lib/nmi_backtrace.c
+++ b/lib/nmi_backtrace.c
@@ -93,8 +93,8 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
 	if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
 		arch_spin_lock(&lock);
 		if (regs && cpu_in_idle(instruction_pointer(regs))) {
-			pr_warn("NMI backtrace for cpu %d skipped: idling at pc %#lx\n",
-				cpu, instruction_pointer(regs));
+			pr_warn("NMI backtrace for cpu %d skipped: idling at %pS\n",
+				cpu, (void *)instruction_pointer(regs));
 		} else {
 			pr_warn("NMI backtrace for cpu %d\n", cpu);
 			if (regs)
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
index 191a238e5a9d..7d36c1e27ff6 100644
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -11,7 +11,7 @@
 	MODULE_PARM_DESC(name, msg);
 
 __param(int, nnodes, 100, "Number of nodes in the rb-tree");
-__param(int, perf_loops, 100000, "Number of iterations modifying the rb-tree");
+__param(int, perf_loops, 1000, "Number of iterations modifying the rb-tree");
 __param(int, check_loops, 100, "Number of iterations modifying and verifying the rb-tree");
 
 struct test_node {
diff --git a/lib/string.c b/lib/string.c
index 5e8d410a93df..64a9e33f1daa 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -1052,144 +1052,3 @@ void fortify_panic(const char *name)
 	BUG();
 }
 EXPORT_SYMBOL(fortify_panic);
-
-#ifdef CONFIG_STRING_SELFTEST
-#include <linux/slab.h>
-#include <linux/module.h>
-
-static __init int memset16_selftest(void)
-{
-	unsigned i, j, k;
-	u16 v, *p;
-
-	p = kmalloc(256 * 2 * 2, GFP_KERNEL);
-	if (!p)
-		return -1;
-
-	for (i = 0; i < 256; i++) {
-		for (j = 0; j < 256; j++) {
-			memset(p, 0xa1, 256 * 2 * sizeof(v));
-			memset16(p + i, 0xb1b2, j);
-			for (k = 0; k < 512; k++) {
-				v = p[k];
-				if (k < i) {
-					if (v != 0xa1a1)
-						goto fail;
-				} else if (k < i + j) {
-					if (v != 0xb1b2)
-						goto fail;
-				} else {
-					if (v != 0xa1a1)
-						goto fail;
-				}
-			}
-		}
-	}
-
-fail:
-	kfree(p);
-	if (i < 256)
-		return (i << 24) | (j << 16) | k;
-	return 0;
-}
-
-static __init int memset32_selftest(void)
-{
-	unsigned i, j, k;
-	u32 v, *p;
-
-	p = kmalloc(256 * 2 * 4, GFP_KERNEL);
-	if (!p)
-		return -1;
-
-	for (i = 0; i < 256; i++) {
-		for (j = 0; j < 256; j++) {
-			memset(p, 0xa1, 256 * 2 * sizeof(v));
-			memset32(p + i, 0xb1b2b3b4, j);
-			for (k = 0; k < 512; k++) {
-				v = p[k];
-				if (k < i) {
-					if (v != 0xa1a1a1a1)
-						goto fail;
-				} else if (k < i + j) {
-					if (v != 0xb1b2b3b4)
-						goto fail;
-				} else {
-					if (v != 0xa1a1a1a1)
-						goto fail;
-				}
-			}
-		}
-	}
-
-fail:
-	kfree(p);
-	if (i < 256)
-		return (i << 24) | (j << 16) | k;
-	return 0;
-}
-
-static __init int memset64_selftest(void)
-{
-	unsigned i, j, k;
-	u64 v, *p;
-
-	p = kmalloc(256 * 2 * 8, GFP_KERNEL);
-	if (!p)
-		return -1;
-
-	for (i = 0; i < 256; i++) {
-		for (j = 0; j < 256; j++) {
-			memset(p, 0xa1, 256 * 2 * sizeof(v));
-			memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j);
-			for (k = 0; k < 512; k++) {
-				v = p[k];
-				if (k < i) {
-					if (v != 0xa1a1a1a1a1a1a1a1ULL)
-						goto fail;
-				} else if (k < i + j) {
-					if (v != 0xb1b2b3b4b5b6b7b8ULL)
-						goto fail;
-				} else {
-					if (v != 0xa1a1a1a1a1a1a1a1ULL)
-						goto fail;
-				}
-			}
-		}
-	}
-
-fail:
-	kfree(p);
-	if (i < 256)
-		return (i << 24) | (j << 16) | k;
-	return 0;
-}
-
-static __init int string_selftest_init(void)
-{
-	int test, subtest;
-
-	test = 1;
-	subtest = memset16_selftest();
-	if (subtest)
-		goto fail;
-
-	test = 2;
-	subtest = memset32_selftest();
-	if (subtest)
-		goto fail;
-
-	test = 3;
-	subtest = memset64_selftest();
-	if (subtest)
-		goto fail;
-
-	pr_info("String selftests succeeded\n");
-	return 0;
-fail:
-	pr_crit("String selftest failure %d.%08x\n", test, subtest);
-	return 0;
-}
-
-module_init(string_selftest_init);
-#endif	/* CONFIG_STRING_SELFTEST */
diff --git a/lib/test_find_bit.c b/lib/test_find_bit.c
new file mode 100644
index 000000000000..f4394a36f9aa
--- /dev/null
+++ b/lib/test_find_bit.c
@@ -0,0 +1,144 @@
+/*
+ * Test for find_*_bit functions.
+ *
+ * Copyright (c) 2017 Cavium.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+/*
+ * find_bit functions are widely used in kernel, so the successful boot
+ * is good enough test for correctness.
+ *
+ * This test is focused on performance of traversing bitmaps. Two typical
+ * scenarios are reproduced:
+ * - randomly filled bitmap with approximately equal number of set and
+ *   cleared bits;
+ * - sparse bitmap with few set bits at random positions.
+ */
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+
+#define BITMAP_LEN	(4096UL * 8 * 10)
+#define SPARSE		500
+
+static DECLARE_BITMAP(bitmap, BITMAP_LEN) __initdata;
+
+/*
+ * This is Schlemiel the Painter's algorithm. It should be called after
+ * all other tests for the same bitmap because it sets all bits of bitmap to 1.
+ */
+static int __init test_find_first_bit(void *bitmap, unsigned long len)
+{
+	unsigned long i, cnt;
+	cycles_t cycles;
+
+	cycles = get_cycles();
+	for (cnt = i = 0; i < len; cnt++) {
+		i = find_first_bit(bitmap, len);
+		__clear_bit(i, bitmap);
+	}
+	cycles = get_cycles() - cycles;
+	pr_err("find_first_bit:\t\t%llu cycles,\t%ld iterations\n",
+	       (u64)cycles, cnt);
+
+	return 0;
+}
+
+static int __init test_find_next_bit(const void *bitmap, unsigned long len)
+{
+	unsigned long i, cnt;
+	cycles_t cycles;
+
+	cycles = get_cycles();
+	for (cnt = i = 0; i < BITMAP_LEN; cnt++)
+		i = find_next_bit(bitmap, BITMAP_LEN, i) + 1;
+	cycles = get_cycles() - cycles;
+	pr_err("find_next_bit:\t\t%llu cycles,\t%ld iterations\n",
+	       (u64)cycles, cnt);
+
+	return 0;
+}
+
+static int __init test_find_next_zero_bit(const void *bitmap, unsigned long len)
+{
+	unsigned long i, cnt;
+	cycles_t cycles;
+
+	cycles = get_cycles();
+	for (cnt = i = 0; i < BITMAP_LEN; cnt++)
+		i = find_next_zero_bit(bitmap, len, i) + 1;
+	cycles = get_cycles() - cycles;
+	pr_err("find_next_zero_bit:\t%llu cycles,\t%ld iterations\n",
+	       (u64)cycles, cnt);
+
+	return 0;
+}
+
+static int __init test_find_last_bit(const void *bitmap, unsigned long len)
+{
+	unsigned long l, cnt = 0;
+	cycles_t cycles;
+
+	cycles = get_cycles();
+	do {
+		cnt++;
+		l = find_last_bit(bitmap, len);
+		if (l >= len)
+			break;
+		len = l;
+	} while (len);
+	cycles = get_cycles() - cycles;
+	pr_err("find_last_bit:\t\t%llu cycles,\t%ld iterations\n",
+	       (u64)cycles, cnt);
+
+	return 0;
+}
+
+static int __init find_bit_test(void)
+{
+	unsigned long nbits = BITMAP_LEN / SPARSE;
+
+	pr_err("\nStart testing find_bit() with random-filled bitmap\n");
+
+	get_random_bytes(bitmap, sizeof(bitmap));
+
+	test_find_next_bit(bitmap, BITMAP_LEN);
+	test_find_next_zero_bit(bitmap, BITMAP_LEN);
+	test_find_last_bit(bitmap, BITMAP_LEN);
+	test_find_first_bit(bitmap, BITMAP_LEN);
+
+	pr_err("\nStart testing find_bit() with sparse bitmap\n");
+
+	bitmap_zero(bitmap, BITMAP_LEN);
+
+	while (nbits--)
+		__set_bit(prandom_u32() % BITMAP_LEN, bitmap);
+
+	test_find_next_bit(bitmap, BITMAP_LEN);
+	test_find_next_zero_bit(bitmap, BITMAP_LEN);
+	test_find_last_bit(bitmap, BITMAP_LEN);
+	test_find_first_bit(bitmap, BITMAP_LEN);
+
+	return 0;
+}
+module_init(find_bit_test);
+
+static void __exit test_find_bit_cleanup(void)
+{
+}
+module_exit(test_find_bit_cleanup);
+
+MODULE_LICENSE("GPL");
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index a25c9763fce1..ef1a3ac1397e 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -353,10 +353,9 @@ static noinline void __init memcg_accounted_kmem_cache(void)
 	 */
 	for (i = 0; i < 5; i++) {
 		p = kmem_cache_alloc(cache, GFP_KERNEL);
-		if (!p) {
-			pr_err("Allocation failed\n");
+		if (!p)
 			goto free_cache;
-		}
+
 		kmem_cache_free(cache, p);
 		msleep(100);
 	}
diff --git a/lib/test_kmod.c b/lib/test_kmod.c
index fba78d25e825..337f408b4de6 100644
--- a/lib/test_kmod.c
+++ b/lib/test_kmod.c
@@ -783,10 +783,8 @@ static int kmod_config_sync_info(struct kmod_test_device *test_dev)
 	free_test_dev_info(test_dev);
 	test_dev->info = vzalloc(config->num_threads *
 				 sizeof(struct kmod_test_device_info));
-	if (!test_dev->info) {
-		dev_err(test_dev->dev, "Cannot alloc test_dev info\n");
+	if (!test_dev->info)
 		return -ENOMEM;
-	}
 
 	return 0;
 }
@@ -1089,10 +1087,8 @@ static struct kmod_test_device *alloc_test_dev_kmod(int idx)
 	struct miscdevice *misc_dev;
 
 	test_dev = vzalloc(sizeof(struct kmod_test_device));
-	if (!test_dev) {
-		pr_err("Cannot alloc test_dev\n");
+	if (!test_dev)
 		goto err_out;
-	}
 
 	mutex_init(&test_dev->config_mutex);
 	mutex_init(&test_dev->trigger_mutex);
diff --git a/lib/test_list_sort.c b/lib/test_list_sort.c
index 28e817387b04..5474f3f3e41d 100644
--- a/lib/test_list_sort.c
+++ b/lib/test_list_sort.c
@@ -76,17 +76,14 @@ static int __init list_sort_test(void)
 	pr_debug("start testing list_sort()\n");
 
 	elts = kcalloc(TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
-	if (!elts) {
-		pr_err("error: cannot allocate memory\n");
+	if (!elts)
 		return err;
-	}
 
 	for (i = 0; i < TEST_LIST_LEN; i++) {
 		el = kmalloc(sizeof(*el), GFP_KERNEL);
-		if (!el) {
-			pr_err("error: cannot allocate memory\n");
+		if (!el)
 			goto exit;
-		}
+
 		 /* force some equivalencies */
 		el->value = prandom_u32() % (TEST_LIST_LEN / 3);
 		el->serial = i;
diff --git a/lib/test_string.c b/lib/test_string.c
new file mode 100644
index 000000000000..0fcdb82dca86
--- /dev/null
+++ b/lib/test_string.c
@@ -0,0 +1,141 @@
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+static __init int memset16_selftest(void)
+{
+	unsigned i, j, k;
+	u16 v, *p;
+
+	p = kmalloc(256 * 2 * 2, GFP_KERNEL);
+	if (!p)
+		return -1;
+
+	for (i = 0; i < 256; i++) {
+		for (j = 0; j < 256; j++) {
+			memset(p, 0xa1, 256 * 2 * sizeof(v));
+			memset16(p + i, 0xb1b2, j);
+			for (k = 0; k < 512; k++) {
+				v = p[k];
+				if (k < i) {
+					if (v != 0xa1a1)
+						goto fail;
+				} else if (k < i + j) {
+					if (v != 0xb1b2)
+						goto fail;
+				} else {
+					if (v != 0xa1a1)
+						goto fail;
+				}
+			}
+		}
+	}
+
+fail:
+	kfree(p);
+	if (i < 256)
+		return (i << 24) | (j << 16) | k;
+	return 0;
+}
+
+static __init int memset32_selftest(void)
+{
+	unsigned i, j, k;
+	u32 v, *p;
+
+	p = kmalloc(256 * 2 * 4, GFP_KERNEL);
+	if (!p)
+		return -1;
+
+	for (i = 0; i < 256; i++) {
+		for (j = 0; j < 256; j++) {
+			memset(p, 0xa1, 256 * 2 * sizeof(v));
+			memset32(p + i, 0xb1b2b3b4, j);
+			for (k = 0; k < 512; k++) {
+				v = p[k];
+				if (k < i) {
+					if (v != 0xa1a1a1a1)
+						goto fail;
+				} else if (k < i + j) {
+					if (v != 0xb1b2b3b4)
+						goto fail;
+				} else {
+					if (v != 0xa1a1a1a1)
+						goto fail;
+				}
+			}
+		}
+	}
+
+fail:
+	kfree(p);
+	if (i < 256)
+		return (i << 24) | (j << 16) | k;
+	return 0;
+}
+
+static __init int memset64_selftest(void)
+{
+	unsigned i, j, k;
+	u64 v, *p;
+
+	p = kmalloc(256 * 2 * 8, GFP_KERNEL);
+	if (!p)
+		return -1;
+
+	for (i = 0; i < 256; i++) {
+		for (j = 0; j < 256; j++) {
+			memset(p, 0xa1, 256 * 2 * sizeof(v));
+			memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j);
+			for (k = 0; k < 512; k++) {
+				v = p[k];
+				if (k < i) {
+					if (v != 0xa1a1a1a1a1a1a1a1ULL)
+						goto fail;
+				} else if (k < i + j) {
+					if (v != 0xb1b2b3b4b5b6b7b8ULL)
+						goto fail;
+				} else {
+					if (v != 0xa1a1a1a1a1a1a1a1ULL)
+						goto fail;
+				}
+			}
+		}
+	}
+
+fail:
+	kfree(p);
+	if (i < 256)
+		return (i << 24) | (j << 16) | k;
+	return 0;
+}
+
+static __init int string_selftest_init(void)
+{
+	int test, subtest;
+
+	test = 1;
+	subtest = memset16_selftest();
+	if (subtest)
+		goto fail;
+
+	test = 2;
+	subtest = memset32_selftest();
+	if (subtest)
+		goto fail;
+
+	test = 3;
+	subtest = memset64_selftest();
+	if (subtest)
+		goto fail;
+
+	pr_info("String selftests succeeded\n");
+	return 0;
+fail:
+	pr_crit("String selftest failure %d.%08x\n", test, subtest);
+	return 0;
+}
+
+module_init(string_selftest_init);
+MODULE_LICENSE("GPL v2");