Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "17 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  drivers/acpi/scan.c: document why we don't need the device_hotplug_lock
  memremap: move from kernel/ to mm/
  lib/test_meminit.c: use GFP_ATOMIC in RCU critical section
  asm-generic: fix -Wtype-limits compiler warnings
  cgroup: kselftest: relax fs_spec checks
  mm/memory_hotplug.c: remove unneeded return for void function
  mm/migrate.c: initialize pud_entry in migrate_vma()
  coredump: split pipe command whitespace before expanding template
  page flags: prioritize kasan bits over last-cpuid
  ubsan: build ubsan.c more conservatively
  kasan: remove clang version check for KASAN_STACK
  mm: compaction: avoid 100% CPU usage during compaction when a task is killed
  mm: migrate: fix reference check race between __find_get_block() and migration
  mm: vmscan: check if mem cgroup is disabled or not before calling memcg slab shrinker
  ocfs2: remove set but not used variable 'last_hash'
  Revert "kmemleak: allow to coexist with fault injection"
  kernel/signal.c: fix a kernel-doc markup

19 files changed, 114 insertions, 76 deletions

diff --git a/arch/mips/vdso/vdso.h b/arch/mips/vdso/vdso.h
index 14b1931be69c..b65b169778e3 100644
--- a/arch/mips/vdso/vdso.h
+++ b/arch/mips/vdso/vdso.h
@@ -9,6 +9,7 @@
 #if _MIPS_SIM != _MIPS_SIM_ABI64 && defined(CONFIG_64BIT)
 
 /* Building 32-bit VDSO for the 64-bit kernel. Fake a 32-bit Kconfig. */
+#define BUILD_VDSO32_64
 #undef CONFIG_64BIT
 #define CONFIG_32BIT 1
 #ifndef __ASSEMBLY__
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 0e28270b0fd8..aad6be5c0af0 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2204,6 +2204,12 @@ int __init acpi_scan_init(void)
 	acpi_gpe_apply_masked_gpes();
 	acpi_update_all_gpes();
 
+	/*
+	 * Although we call __add_memory() that is documented to require the
+	 * device_hotplug_lock, it is not necessary here because this is an
+	 * early code when userspace or any other code path cannot trigger
+	 * hotplug/hotunplug operations.
+	 */
 	mutex_lock(&acpi_scan_lock);
 	/*
 	 * Enumerate devices in the ACPI namespace.
diff --git a/fs/coredump.c b/fs/coredump.c
index e42e17e55bfd..b1ea7dfbd149 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -7,6 +7,7 @@
 #include <linux/stat.h>
 #include <linux/fcntl.h>
 #include <linux/swap.h>
+#include <linux/ctype.h>
 #include <linux/string.h>
 #include <linux/init.h>
 #include <linux/pagemap.h>
@@ -187,11 +188,13 @@ put_exe_file:
  * name into corename, which must have space for at least
  * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
  */
-static int format_corename(struct core_name *cn, struct coredump_params *cprm)
+static int format_corename(struct core_name *cn, struct coredump_params *cprm,
+			   size_t **argv, int *argc)
 {
 	const struct cred *cred = current_cred();
 	const char *pat_ptr = core_pattern;
 	int ispipe = (*pat_ptr == '|');
+	bool was_space = false;
 	int pid_in_pattern = 0;
 	int err = 0;
 
@@ -201,12 +204,35 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
 		return -ENOMEM;
 	cn->corename[0] = '\0';
 
-	if (ispipe)
+	if (ispipe) {
+		int argvs = sizeof(core_pattern) / 2;
+		(*argv) = kmalloc_array(argvs, sizeof(**argv), GFP_KERNEL);
+		if (!(*argv))
+			return -ENOMEM;
+		(*argv)[(*argc)++] = 0;
 		++pat_ptr;
+	}
 
 	/* Repeat as long as we have more pattern to process and more output
 	   space */
 	while (*pat_ptr) {
+		/*
+		 * Split on spaces before doing template expansion so that
+		 * %e and %E don't get split if they have spaces in them
+		 */
+		if (ispipe) {
+			if (isspace(*pat_ptr)) {
+				was_space = true;
+				pat_ptr++;
+				continue;
+			} else if (was_space) {
+				was_space = false;
+				err = cn_printf(cn, "%c", '\0');
+				if (err)
+					return err;
+				(*argv)[(*argc)++] = cn->used;
+			}
+		}
 		if (*pat_ptr != '%') {
 			err = cn_printf(cn, "%c", *pat_ptr++);
 		} else {
@@ -546,6 +572,8 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 	struct cred *cred;
 	int retval = 0;
 	int ispipe;
+	size_t *argv = NULL;
+	int argc = 0;
 	struct files_struct *displaced;
 	/* require nonrelative corefile path and be extra careful */
 	bool need_suid_safe = false;
@@ -592,9 +620,10 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 
 	old_cred = override_creds(cred);
 
-	ispipe = format_corename(&cn, &cprm);
+	ispipe = format_corename(&cn, &cprm, &argv, &argc);
 
 	if (ispipe) {
+		int argi;
 		int dump_count;
 		char **helper_argv;
 		struct subprocess_info *sub_info;
@@ -637,12 +666,16 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 			goto fail_dropcount;
 		}
 
-		helper_argv = argv_split(GFP_KERNEL, cn.corename, NULL);
+		helper_argv = kmalloc_array(argc + 1, sizeof(*helper_argv),
+					    GFP_KERNEL);
 		if (!helper_argv) {
 			printk(KERN_WARNING "%s failed to allocate memory\n",
 			       __func__);
 			goto fail_dropcount;
 		}
+		for (argi = 0; argi < argc; argi++)
+			helper_argv[argi] = cn.corename + argv[argi];
+		helper_argv[argi] = NULL;
 
 		retval = -ENOMEM;
 		sub_info = call_usermodehelper_setup(helper_argv[0],
@@ -652,7 +685,7 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 			retval = call_usermodehelper_exec(sub_info,
 							  UMH_WAIT_EXEC);
 
-		argv_free(helper_argv);
+		kfree(helper_argv);
 		if (retval) {
 			printk(KERN_INFO "Core dump to |%s pipe failed\n",
 			       cn.corename);
@@ -766,6 +799,7 @@ fail_dropcount:
 	if (ispipe)
 		atomic_dec(&core_dump_count);
 fail_unlock:
+	kfree(argv);
 	kfree(cn.corename);
 	coredump_finish(mm, core_dumped);
 	revert_creds(old_cred);
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 385f3aaa2448..90c830e3758e 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -3825,7 +3825,6 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
 	u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
 	int low_bucket = 0, bucket, high_bucket;
 	struct ocfs2_xattr_bucket *search;
-	u32 last_hash;
 	u64 blkno, lower_blkno = 0;
 
 	search = ocfs2_xattr_bucket_new(inode);
@@ -3869,8 +3868,6 @@ static int ocfs2_xattr_bucket_find(struct inode *inode,
 		if (xh->xh_count)
 			xe = &xh->xh_entries[le16_to_cpu(xh->xh_count) - 1];
 
-		last_hash = le32_to_cpu(xe->xe_name_hash);
-
 		/* record lower_blkno which may be the insert place. */
 		lower_blkno = blkno;
 
diff --git a/include/asm-generic/getorder.h b/include/asm-generic/getorder.h
index c64bea7a52be..e9f20b813a69 100644
--- a/include/asm-generic/getorder.h
+++ b/include/asm-generic/getorder.h
@@ -7,24 +7,6 @@
 #include <linux/compiler.h>
 #include <linux/log2.h>
 
-/*
- * Runtime evaluation of get_order()
- */
-static inline __attribute_const__
-int __get_order(unsigned long size)
-{
-	int order;
-
-	size--;
-	size >>= PAGE_SHIFT;
-#if BITS_PER_LONG == 32
-	order = fls(size);
-#else
-	order = fls64(size);
-#endif
-	return order;
-}
-
 /**
  * get_order - Determine the allocation order of a memory size
  * @size: The size for which to get the order
@@ -43,19 +25,27 @@ int __get_order(unsigned long size)
  * to hold an object of the specified size.
  *
  * The result is undefined if the size is 0.
- *
- * This function may be used to initialise variables with compile time
- * evaluations of constants.
  */
-#define get_order(n)						\
-(								\
-	__builtin_constant_p(n) ? (				\
-		((n) == 0UL) ? BITS_PER_LONG - PAGE_SHIFT :	\
-		(((n) < (1UL << PAGE_SHIFT)) ? 0 :		\
-		 ilog2((n) - 1) - PAGE_SHIFT + 1)		\
-	) :							\
-	__get_order(n)						\
-)
+static inline __attribute_const__ int get_order(unsigned long size)
+{
+	if (__builtin_constant_p(size)) {
+		if (!size)
+			return BITS_PER_LONG - PAGE_SHIFT;
+
+		if (size < (1UL << PAGE_SHIFT))
+			return 0;
+
+		return ilog2((size) - 1) - PAGE_SHIFT + 1;
+	}
+
+	size--;
+	size >>= PAGE_SHIFT;
+#if BITS_PER_LONG == 32
+	return fls(size);
+#else
+	return fls64(size);
+#endif
+}
 
 #endif	/* __ASSEMBLY__ */
 
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h
index 1dda31825ec4..71283739ffd2 100644
--- a/include/linux/page-flags-layout.h
+++ b/include/linux/page-flags-layout.h
@@ -32,6 +32,7 @@
 
 #endif /* CONFIG_SPARSEMEM */
 
+#ifndef BUILD_VDSO32_64
 /*
  * page->flags layout:
  *
@@ -76,20 +77,22 @@
 #define LAST_CPUPID_SHIFT 0
 #endif
 
-#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_CPUPID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
+#ifdef CONFIG_KASAN_SW_TAGS
+#define KASAN_TAG_WIDTH 8
+#else
+#define KASAN_TAG_WIDTH 0
+#endif
+
+#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_CPUPID_SHIFT+KASAN_TAG_WIDTH \
+	<= BITS_PER_LONG - NR_PAGEFLAGS
 #define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT
 #else
 #define LAST_CPUPID_WIDTH 0
 #endif
 
-#ifdef CONFIG_KASAN_SW_TAGS
-#define KASAN_TAG_WIDTH 8
 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH+LAST_CPUPID_WIDTH+KASAN_TAG_WIDTH \
 	> BITS_PER_LONG - NR_PAGEFLAGS
-#error "KASAN: not enough bits in page flags for tag"
-#endif
-#else
-#define KASAN_TAG_WIDTH 0
+#error "Not enough bits in page flags"
 #endif
 
 /*
@@ -104,4 +107,5 @@
 #define LAST_CPUPID_NOT_IN_PAGE_FLAGS
 #endif
 
+#endif
 #endif /* _LINUX_PAGE_FLAGS_LAYOUT */
diff --git a/kernel/Makefile b/kernel/Makefile
index a8d923b5481b..ef0d95a190b4 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -111,7 +111,6 @@ obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
 obj-$(CONFIG_TORTURE_TEST) += torture.o
 
 obj-$(CONFIG_HAS_IOMEM) += iomem.o
-obj-$(CONFIG_ZONE_DEVICE) += memremap.o
 obj-$(CONFIG_RSEQ) += rseq.o
 
 obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o
diff --git a/kernel/signal.c b/kernel/signal.c
index 349f5a67f100..e667be6907d7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -349,7 +349,7 @@ void task_clear_jobctl_pending(struct task_struct *task, unsigned long mask)
  * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop.
  * Group stop states are cleared and the group stop count is consumed if
  * %JOBCTL_STOP_CONSUME was set.  If the consumption completes the group
- * stop, the appropriate %SIGNAL_* flags are set.
+ * stop, the appropriate `SIGNAL_*` flags are set.
  *
  * CONTEXT:
  * Must be called with @task->sighand->siglock held.
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index 4fafba1a923b..7fa97a8b5717 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -106,7 +106,6 @@ endchoice
 
 config KASAN_STACK_ENABLE
 	bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST
-	default !(CLANG_VERSION < 90000)
 	depends on KASAN
 	help
 	  The LLVM stack address sanitizer has a know problem that
@@ -115,11 +114,11 @@ config KASAN_STACK_ENABLE
 	  Disabling asan-stack makes it safe to run kernels build
 	  with clang-8 with KASAN enabled, though it loses some of
 	  the functionality.
-	  This feature is always disabled when compile-testing with clang-8
-	  or earlier to avoid cluttering the output in stack overflow
-	  warnings, but clang-8 users can still enable it for builds without
-	  CONFIG_COMPILE_TEST.  On gcc and later clang versions it is
-	  assumed to always be safe to use and enabled by default.
+	  This feature is always disabled when compile-testing with clang
+	  to avoid cluttering the output in stack overflow warnings,
+	  but clang users can still enable it for builds without
+	  CONFIG_COMPILE_TEST.	On gcc it is assumed to always be safe
+	  to use and enabled by default.
 
 config KASAN_STACK
 	int
diff --git a/lib/Makefile b/lib/Makefile
index 095601ce371d..29c02a924973 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -279,7 +279,8 @@ obj-$(CONFIG_UCS2_STRING) += ucs2_string.o
 obj-$(CONFIG_UBSAN) += ubsan.o
 
 UBSAN_SANITIZE_ubsan.o := n
-CFLAGS_ubsan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+KASAN_SANITIZE_ubsan.o := n
+CFLAGS_ubsan.o := $(call cc-option, -fno-stack-protector) $(DISABLE_STACKLEAK_PLUGIN)
 
 obj-$(CONFIG_SBITMAP) += sbitmap.o
 
diff --git a/lib/test_meminit.c b/lib/test_meminit.c
index 62d19f270cad..9729f271d150 100644
--- a/lib/test_meminit.c
+++ b/lib/test_meminit.c
@@ -222,7 +222,7 @@ static int __init do_kmem_cache_size(size_t size, bool want_ctor,
 		 * Copy the buffer to check that it's not wiped on
 		 * free().
 		 */
-		buf_copy = kmalloc(size, GFP_KERNEL);
+		buf_copy = kmalloc(size, GFP_ATOMIC);
 		if (buf_copy)
 			memcpy(buf_copy, buf, size);
 
diff --git a/mm/Makefile b/mm/Makefile
index 338e528ad436..d0b295c3b764 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -102,5 +102,6 @@ obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o
 obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o
 obj-$(CONFIG_HARDENED_USERCOPY) += usercopy.o
 obj-$(CONFIG_PERCPU_STATS) += percpu-stats.o
+obj-$(CONFIG_ZONE_DEVICE) += memremap.o
 obj-$(CONFIG_HMM_MIRROR) += hmm.o
 obj-$(CONFIG_MEMFD_CREATE) += memfd.o
diff --git a/mm/compaction.c b/mm/compaction.c
index 9e1b9acb116b..952dc2fb24e5 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -842,13 +842,15 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 
 		/*
 		 * Periodically drop the lock (if held) regardless of its
-		 * contention, to give chance to IRQs. Abort async compaction
-		 * if contended.
+		 * contention, to give chance to IRQs. Abort completely if
+		 * a fatal signal is pending.
 		 */
 		if (!(low_pfn % SWAP_CLUSTER_MAX)
 		    && compact_unlock_should_abort(&pgdat->lru_lock,
-					    flags, &locked, cc))
-			break;
+					    flags, &locked, cc)) {
+			low_pfn = 0;
+			goto fatal_pending;
+		}
 
 		if (!pfn_valid_within(low_pfn))
 			goto isolate_fail;
@@ -1060,6 +1062,7 @@ isolate_abort:
 	trace_mm_compaction_isolate_migratepages(start_pfn, low_pfn,
 						nr_scanned, nr_isolated);
 
+fatal_pending:
 	cc->total_migrate_scanned += nr_scanned;
 	if (nr_isolated)
 		count_compact_events(COMPACTISOLATED, nr_isolated);
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index dbbd518fb6b3..6e9e8cca663e 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -114,7 +114,7 @@
 /* GFP bitmask for kmemleak internal allocations */
 #define gfp_kmemleak_mask(gfp)	(((gfp) & (GFP_KERNEL | GFP_ATOMIC)) | \
 				 __GFP_NORETRY | __GFP_NOMEMALLOC | \
-				 __GFP_NOWARN | __GFP_NOFAIL)
+				 __GFP_NOWARN)
 
 /* scanning area inside a memory block */
 struct kmemleak_scan_area {
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 2a9bbddb0e55..c73f09913165 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -132,7 +132,6 @@ static void release_memory_resource(struct resource *res)
 		return;
 	release_resource(res);
 	kfree(res);
-	return;
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
@@ -979,7 +978,6 @@ static void rollback_node_hotadd(int nid)
 	arch_refresh_nodedata(nid, NULL);
 	free_percpu(pgdat->per_cpu_nodestats);
 	arch_free_nodedata(pgdat);
-	return;
 }
 
 
diff --git a/kernel/memremap.c b/mm/memremap.c
index 6ee03a816d67..6ee03a816d67 100644
--- a/kernel/memremap.c
+++ b/mm/memremap.c
diff --git a/mm/migrate.c b/mm/migrate.c
index 8992741f10aa..a42858d8e00b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -767,12 +767,12 @@ recheck_buffers:
 			}
 			bh = bh->b_this_page;
 		} while (bh != head);
-		spin_unlock(&mapping->private_lock);
 		if (busy) {
 			if (invalidated) {
 				rc = -EAGAIN;
 				goto unlock_buffers;
 			}
+			spin_unlock(&mapping->private_lock);
 			invalidate_bh_lrus();
 			invalidated = true;
 			goto recheck_buffers;
@@ -805,6 +805,8 @@ recheck_buffers:
 
 	rc = MIGRATEPAGE_SUCCESS;
 unlock_buffers:
+	if (check_refs)
+		spin_unlock(&mapping->private_lock);
 	bh = head;
 	do {
 		unlock_buffer(bh);
@@ -2338,16 +2340,13 @@ next:
 static void migrate_vma_collect(struct migrate_vma *migrate)
 {
 	struct mmu_notifier_range range;
-	struct mm_walk mm_walk;
-
-	mm_walk.pmd_entry = migrate_vma_collect_pmd;
-	mm_walk.pte_entry = NULL;
-	mm_walk.pte_hole = migrate_vma_collect_hole;
-	mm_walk.hugetlb_entry = NULL;
-	mm_walk.test_walk = NULL;
-	mm_walk.vma = migrate->vma;
-	mm_walk.mm = migrate->vma->vm_mm;
-	mm_walk.private = migrate;
+	struct mm_walk mm_walk = {
+		.pmd_entry = migrate_vma_collect_pmd,
+		.pte_hole = migrate_vma_collect_hole,
+		.vma = migrate->vma,
+		.mm = migrate->vma->vm_mm,
+		.private = migrate,
+	};
 
 	mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, NULL, mm_walk.mm,
 				migrate->start,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 44df66a98f2a..dbdc46a84f63 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -699,7 +699,14 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
 	unsigned long ret, freed = 0;
 	struct shrinker *shrinker;
 
-	if (!mem_cgroup_is_root(memcg))
+	/*
+	 * The root memcg might be allocated even though memcg is disabled
+	 * via "cgroup_disable=memory" boot parameter.  This could make
+	 * mem_cgroup_is_root() return false, then just run memcg slab
+	 * shrink, but skip global shrink.  This may result in premature
+	 * oom.
+	 */
+	if (!mem_cgroup_disabled() && !mem_cgroup_is_root(memcg))
 		return shrink_slab_memcg(gfp_mask, nid, memcg, priority);
 
 	if (!down_read_trylock(&shrinker_rwsem))
diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
index 4c223266299a..bdb69599c4bd 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -191,8 +191,7 @@ int cg_find_unified_root(char *root, size_t len)
 		strtok(NULL, delim);
 		strtok(NULL, delim);
 
-		if (strcmp(fs, "cgroup") == 0 &&
-		    strcmp(type, "cgroup2") == 0) {
+		if (strcmp(type, "cgroup2") == 0) {
 			strncpy(root, mount, len);
 			return 0;
 		}