Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:

 - More MM work. 100ish more to go. Mike Rapoport's "mm: remove
   __ARCH_HAS_5LEVEL_HACK" series should fix the current ppc issue

 - Various other little subsystems

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits)
  lib/ubsan.c: fix gcc-10 warnings
  tools/testing/selftests/vm: remove duplicate headers
  selftests: vm: pkeys: fix multilib builds for x86
  selftests: vm: pkeys: use the correct page size on powerpc
  selftests/vm/pkeys: override access right definitions on powerpc
  selftests/vm/pkeys: test correct behaviour of pkey-0
  selftests/vm/pkeys: introduce a sub-page allocator
  selftests/vm/pkeys: detect write violation on a mapped access-denied-key page
  selftests/vm/pkeys: associate key on a mapped page and detect write violation
  selftests/vm/pkeys: associate key on a mapped page and detect access violation
  selftests/vm/pkeys: improve checks to determine pkey support
  selftests/vm/pkeys: fix assertion in test_pkey_alloc_exhaust()
  selftests/vm/pkeys: fix number of reserved powerpc pkeys
  selftests/vm/pkeys: introduce powerpc support
  selftests/vm/pkeys: introduce generic pkey abstractions
  selftests: vm: pkeys: use the correct huge page size
  selftests/vm/pkeys: fix alloc_random_pkey() to make it really random
  selftests/vm/pkeys: fix assertion in pkey_disable_set/clear()
  selftests/vm/pkeys: fix pkey_disable_clear()
  selftests: vm: pkeys: add helpers for pkey bits
  ...

26 files changed, 516 insertions, 173 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index e3490ecac839..cffc276fa19c 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -133,6 +133,9 @@ config HAVE_FAST_GUP
 	depends on MMU
 	bool
 
+# Don't discard allocated memory used to track "memory" and "reserved" memblocks
+# after early boot, so it can still be used to test for validity of memory.
+# Also, memblocks are updated with memory hot(un)plug.
 config ARCH_KEEP_MEMBLOCK
 	bool
 
@@ -155,6 +158,7 @@ config MEMORY_HOTPLUG
 	bool "Allow for memory hot-add"
 	depends on SPARSEMEM || X86_64_ACPI_NUMA
 	depends on ARCH_ENABLE_MEMORY_HOTPLUG
+	depends on 64BIT || BROKEN
 	select NUMA_KEEP_MEMINFO if NUMA
 
 config MEMORY_HOTPLUG_SPARSE
diff --git a/mm/Makefile b/mm/Makefile
index fccd3756b25f..662fd1504646 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
 obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
 obj-$(CONFIG_DEBUG_RODATA_TEST) += rodata_test.o
+obj-$(CONFIG_DEBUG_VM_PGTABLE) += debug_vm_pgtable.o
 obj-$(CONFIG_PAGE_OWNER) += page_owner.o
 obj-$(CONFIG_CLEANCACHE) += cleancache.o
 obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
diff --git a/mm/compaction.c b/mm/compaction.c
index 14d2fe231ea4..fd988b7e5f2b 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1401,7 +1401,7 @@ fast_isolate_freepages(struct compact_control *cc)
 		if (scan_start) {
 			/*
 			 * Use the highest PFN found above min. If one was
-			 * not found, be pessemistic for direct compaction
+			 * not found, be pessimistic for direct compaction
 			 * and use the min mark.
 			 */
 			if (highest) {
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
new file mode 100644
index 000000000000..188c18908964
--- /dev/null
+++ b/mm/debug_vm_pgtable.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This kernel test validates architecture page table helpers and
+ * accessors and helps in verifying their continued compliance with
+ * expected generic MM semantics.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ *
+ * Author: Anshuman Khandual <anshuman.khandual@arm.com>
+ */
+#define pr_fmt(fmt) "debug_vm_pgtable: %s: " fmt, __func__
+
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/hugetlb.h>
+#include <linux/kernel.h>
+#include <linux/kconfig.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/mm_types.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/spinlock.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/start_kernel.h>
+#include <linux/sched/mm.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+#define VMFLAGS	(VM_READ|VM_WRITE|VM_EXEC)
+
+/*
+ * On s390 platform, the lower 4 bits are used to identify given page table
+ * entry type. But these bits might affect the ability to clear entries with
+ * pxx_clear() because of how dynamic page table folding works on s390. So
+ * while loading up the entries do not change the lower 4 bits. It does not
+ * have affect any other platform.
+ */
+#define S390_MASK_BITS	4
+#define RANDOM_ORVALUE	GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS)
+#define RANDOM_NZVALUE	GENMASK(7, 0)
+
+static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pte_t pte = pfn_pte(pfn, prot);
+
+	WARN_ON(!pte_same(pte, pte));
+	WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
+	WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
+	WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
+	WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
+	WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
+	WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pmd_t pmd = pfn_pmd(pfn, prot);
+
+	WARN_ON(!pmd_same(pmd, pmd));
+	WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
+	WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
+	WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
+	WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
+	WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
+	WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
+	/*
+	 * A huge page does not point to next level page table
+	 * entry. Hence this must qualify as pmd_bad().
+	 */
+	WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pud_t pud = pfn_pud(pfn, prot);
+
+	WARN_ON(!pud_same(pud, pud));
+	WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
+	WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
+	WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
+	WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
+
+	if (mm_pmd_folded(mm))
+		return;
+
+	/*
+	 * A huge page does not point to next level page table
+	 * entry. Hence this must qualify as pud_bad().
+	 */
+	WARN_ON(!pud_bad(pud_mkhuge(pud)));
+}
+#else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+#else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	p4d_t p4d;
+
+	memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
+	WARN_ON(!p4d_same(p4d, p4d));
+}
+
+static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pgd_t pgd;
+
+	memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
+	WARN_ON(!pgd_same(pgd, pgd));
+}
+
+#ifndef __PAGETABLE_PUD_FOLDED
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
+{
+	pud_t pud = READ_ONCE(*pudp);
+
+	if (mm_pmd_folded(mm))
+		return;
+
+	pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
+	WRITE_ONCE(*pudp, pud);
+	pud_clear(pudp);
+	pud = READ_ONCE(*pudp);
+	WARN_ON(!pud_none(pud));
+}
+
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+				      pmd_t *pmdp)
+{
+	pud_t pud;
+
+	if (mm_pmd_folded(mm))
+		return;
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as pud_bad().
+	 */
+	pmd_clear(pmdp);
+	pud_clear(pudp);
+	pud_populate(mm, pudp, pmdp);
+	pud = READ_ONCE(*pudp);
+	WARN_ON(pud_bad(pud));
+}
+#else  /* !__PAGETABLE_PUD_FOLDED */
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+				      pmd_t *pmdp)
+{
+}
+#endif /* PAGETABLE_PUD_FOLDED */
+
+#ifndef __PAGETABLE_P4D_FOLDED
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
+{
+	p4d_t p4d = READ_ONCE(*p4dp);
+
+	if (mm_pud_folded(mm))
+		return;
+
+	p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
+	WRITE_ONCE(*p4dp, p4d);
+	p4d_clear(p4dp);
+	p4d = READ_ONCE(*p4dp);
+	WARN_ON(!p4d_none(p4d));
+}
+
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+				      pud_t *pudp)
+{
+	p4d_t p4d;
+
+	if (mm_pud_folded(mm))
+		return;
+
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as p4d_bad().
+	 */
+	pud_clear(pudp);
+	p4d_clear(p4dp);
+	p4d_populate(mm, p4dp, pudp);
+	p4d = READ_ONCE(*p4dp);
+	WARN_ON(p4d_bad(p4d));
+}
+
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
+{
+	pgd_t pgd = READ_ONCE(*pgdp);
+
+	if (mm_p4d_folded(mm))
+		return;
+
+	pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
+	WRITE_ONCE(*pgdp, pgd);
+	pgd_clear(pgdp);
+	pgd = READ_ONCE(*pgdp);
+	WARN_ON(!pgd_none(pgd));
+}
+
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+				      p4d_t *p4dp)
+{
+	pgd_t pgd;
+
+	if (mm_p4d_folded(mm))
+		return;
+
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as pgd_bad().
+	 */
+	p4d_clear(p4dp);
+	pgd_clear(pgdp);
+	pgd_populate(mm, pgdp, p4dp);
+	pgd = READ_ONCE(*pgdp);
+	WARN_ON(pgd_bad(pgd));
+}
+#else  /* !__PAGETABLE_P4D_FOLDED */
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+				      pud_t *pudp)
+{
+}
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+				      p4d_t *p4dp)
+{
+}
+#endif /* PAGETABLE_P4D_FOLDED */
+
+static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
+				   unsigned long vaddr)
+{
+	pte_t pte = READ_ONCE(*ptep);
+
+	pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
+	set_pte_at(mm, vaddr, ptep, pte);
+	barrier();
+	pte_clear(mm, vaddr, ptep);
+	pte = READ_ONCE(*ptep);
+	WARN_ON(!pte_none(pte));
+}
+
+static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
+{
+	pmd_t pmd = READ_ONCE(*pmdp);
+
+	pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
+	WRITE_ONCE(*pmdp, pmd);
+	pmd_clear(pmdp);
+	pmd = READ_ONCE(*pmdp);
+	WARN_ON(!pmd_none(pmd));
+}
+
+static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
+				      pgtable_t pgtable)
+{
+	pmd_t pmd;
+
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as pmd_bad().
+	 */
+	pmd_clear(pmdp);
+	pmd_populate(mm, pmdp, pgtable);
+	pmd = READ_ONCE(*pmdp);
+	WARN_ON(pmd_bad(pmd));
+}
+
+static unsigned long __init get_random_vaddr(void)
+{
+	unsigned long random_vaddr, random_pages, total_user_pages;
+
+	total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
+
+	random_pages = get_random_long() % total_user_pages;
+	random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
+
+	return random_vaddr;
+}
+
+static int __init debug_vm_pgtable(void)
+{
+	struct mm_struct *mm;
+	pgd_t *pgdp;
+	p4d_t *p4dp, *saved_p4dp;
+	pud_t *pudp, *saved_pudp;
+	pmd_t *pmdp, *saved_pmdp, pmd;
+	pte_t *ptep;
+	pgtable_t saved_ptep;
+	pgprot_t prot;
+	phys_addr_t paddr;
+	unsigned long vaddr, pte_aligned, pmd_aligned;
+	unsigned long pud_aligned, p4d_aligned, pgd_aligned;
+	spinlock_t *uninitialized_var(ptl);
+
+	pr_info("Validating architecture page table helpers\n");
+	prot = vm_get_page_prot(VMFLAGS);
+	vaddr = get_random_vaddr();
+	mm = mm_alloc();
+	if (!mm) {
+		pr_err("mm_struct allocation failed\n");
+		return 1;
+	}
+
+	/*
+	 * PFN for mapping at PTE level is determined from a standard kernel
+	 * text symbol. But pfns for higher page table levels are derived by
+	 * masking lower bits of this real pfn. These derived pfns might not
+	 * exist on the platform but that does not really matter as pfn_pxx()
+	 * helpers will still create appropriate entries for the test. This
+	 * helps avoid large memory block allocations to be used for mapping
+	 * at higher page table levels.
+	 */
+	paddr = __pa_symbol(&start_kernel);
+
+	pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
+	pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
+	pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
+	p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
+	pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
+	WARN_ON(!pfn_valid(pte_aligned));
+
+	pgdp = pgd_offset(mm, vaddr);
+	p4dp = p4d_alloc(mm, pgdp, vaddr);
+	pudp = pud_alloc(mm, p4dp, vaddr);
+	pmdp = pmd_alloc(mm, pudp, vaddr);
+	ptep = pte_alloc_map_lock(mm, pmdp, vaddr, &ptl);
+
+	/*
+	 * Save all the page table page addresses as the page table
+	 * entries will be used for testing with random or garbage
+	 * values. These saved addresses will be used for freeing
+	 * page table pages.
+	 */
+	pmd = READ_ONCE(*pmdp);
+	saved_p4dp = p4d_offset(pgdp, 0UL);
+	saved_pudp = pud_offset(p4dp, 0UL);
+	saved_pmdp = pmd_offset(pudp, 0UL);
+	saved_ptep = pmd_pgtable(pmd);
+
+	pte_basic_tests(pte_aligned, prot);
+	pmd_basic_tests(pmd_aligned, prot);
+	pud_basic_tests(pud_aligned, prot);
+	p4d_basic_tests(p4d_aligned, prot);
+	pgd_basic_tests(pgd_aligned, prot);
+
+	pte_clear_tests(mm, ptep, vaddr);
+	pmd_clear_tests(mm, pmdp);
+	pud_clear_tests(mm, pudp);
+	p4d_clear_tests(mm, p4dp);
+	pgd_clear_tests(mm, pgdp);
+
+	pte_unmap_unlock(ptep, ptl);
+
+	pmd_populate_tests(mm, pmdp, saved_ptep);
+	pud_populate_tests(mm, pudp, saved_pmdp);
+	p4d_populate_tests(mm, p4dp, saved_pudp);
+	pgd_populate_tests(mm, pgdp, saved_p4dp);
+
+	p4d_free(mm, saved_p4dp);
+	pud_free(mm, saved_pudp);
+	pmd_free(mm, saved_pmdp);
+	pte_free(mm, saved_ptep);
+
+	mm_dec_nr_puds(mm);
+	mm_dec_nr_pmds(mm);
+	mm_dec_nr_ptes(mm);
+	mmdrop(mm);
+	return 0;
+}
+late_initcall(debug_vm_pgtable);
diff --git a/mm/filemap.c b/mm/filemap.c
index 455990621989..b1a41890d80e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1256,7 +1256,7 @@ EXPORT_SYMBOL_GPL(add_page_wait_queue);
  * instead.
  *
  * The read of PG_waiters has to be after (or concurrently with) PG_locked
- * being cleared, but a memory barrier should be unneccssary since it is
+ * being cleared, but a memory barrier should be unnecessary since it is
  * in the same byte as PG_locked.
  */
 static inline bool clear_bit_unlock_is_negative_byte(long nr, volatile void *mem)
diff --git a/mm/frontswap.c b/mm/frontswap.c
index 60bb20e8a951..bfa3a339253e 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -87,7 +87,7 @@ static inline void inc_frontswap_invalidates(void) { }
  *
  * This would not guards us against the user deciding to call swapoff right as
  * we are calling the backend to initialize (so swapon is in action).
- * Fortunatly for us, the swapon_mutex has been taked by the callee so we are
+ * Fortunately for us, the swapon_mutex has been taken by the callee so we are
  * OK. The other scenario where calls to frontswap_store (called via
  * swap_writepage) is racing with frontswap_invalidate_area (called via
  * swapoff) is again guarded by the swap subsystem.
@@ -413,8 +413,8 @@ static int __frontswap_unuse_pages(unsigned long total, unsigned long *unused,
 }
 
 /*
- * Used to check if it's necessory and feasible to unuse pages.
- * Return 1 when nothing to do, 0 when need to shink pages,
+ * Used to check if it's necessary and feasible to unuse pages.
+ * Return 1 when nothing to do, 0 when need to shrink pages,
  * error code when there is an error.
  */
 static int __frontswap_shrink(unsigned long target_pages,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index e8669885232f..4368e964d2aa 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -522,7 +522,7 @@ void prep_transhuge_page(struct page *page)
 bool is_transparent_hugepage(struct page *page)
 {
 	if (!PageCompound(page))
-		return 0;
+		return false;
 
 	page = compound_head(page);
 	return is_huge_zero_page(page) ||
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ac0d7bbc0692..dcb34d7f5562 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -85,7 +85,7 @@ static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
 	spin_unlock(&spool->lock);
 
 	/* If no pages are used, and no other handles to the subpool
-	 * remain, give up any reservations mased on minimum size and
+	 * remain, give up any reservations based on minimum size and
 	 * free the subpool */
 	if (free) {
 		if (spool->min_hpages != -1)
@@ -133,7 +133,7 @@ void hugepage_put_subpool(struct hugepage_subpool *spool)
  * the request.  Otherwise, return the number of pages by which the
  * global pools must be adjusted (upward).  The returned value may
  * only be different than the passed value (delta) in the case where
- * a subpool minimum size must be manitained.
+ * a subpool minimum size must be maintained.
  */
 static long hugepage_subpool_get_pages(struct hugepage_subpool *spool,
 				      long delta)
@@ -473,7 +473,7 @@ out_of_memory:
  *
  * Return the number of new huge pages added to the map.  This number is greater
  * than or equal to zero.  If file_region entries needed to be allocated for
- * this operation and we were not able to allocate, it ruturns -ENOMEM.
+ * this operation and we were not able to allocate, it returns -ENOMEM.
  * region_add of regions of length 1 never allocate file_regions and cannot
  * fail; region_chg will always allocate at least 1 entry and a region_add for
  * 1 page will only require at most 1 entry.
@@ -988,7 +988,7 @@ static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
 		 * We know VM_NORESERVE is not set.  Therefore, there SHOULD
 		 * be a region map for all pages.  The only situation where
 		 * there is no region map is if a hole was punched via
-		 * fallocate.  In this case, there really are no reverves to
+		 * fallocate.  In this case, there really are no reserves to
 		 * use.  This situation is indicated if chg != 0.
 		 */
 		if (chg)
@@ -1519,7 +1519,7 @@ static void prep_compound_gigantic_page(struct page *page, unsigned int order)
 		 * For gigantic hugepages allocated through bootmem at
 		 * boot, it's safer to be consistent with the not-gigantic
 		 * hugepages and clear the PG_reserved bit from all tail pages
-		 * too.  Otherwse drivers using get_user_pages() to access tail
+		 * too.  Otherwise drivers using get_user_pages() to access tail
 		 * pages may get the reference counting wrong if they see
 		 * PG_reserved set on a tail page (despite the head page not
 		 * having PG_reserved set).  Enforcing this consistency between
@@ -4579,9 +4579,9 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	/*
 	 * entry could be a migration/hwpoison entry at this point, so this
 	 * check prevents the kernel from going below assuming that we have
-	 * a active hugepage in pagecache. This goto expects the 2nd page fault,
-	 * and is_hugetlb_entry_(migration|hwpoisoned) check will properly
-	 * handle it.
+	 * an active hugepage in pagecache. This goto expects the 2nd page
+	 * fault, and is_hugetlb_entry_(migration|hwpoisoned) check will
+	 * properly handle it.
 	 */
 	if (!pte_present(entry))
 		goto out_mutex;
diff --git a/mm/internal.h b/mm/internal.h
index 9117bca90f4b..791e4b5a807c 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -132,7 +132,7 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
  *
  * zonelist, preferred_zone and highest_zoneidx are set first in
  * __alloc_pages_nodemask() for the fast path, and might be later changed
- * in __alloc_pages_slowpath(). All other functions pass the whole strucure
+ * in __alloc_pages_slowpath(). All other functions pass the whole structure
  * by a const pointer.
  */
 struct alloc_context {
diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index ce45c491ebcd..fe6be0be1f76 100644
--- a/mm/kasan/init.c
+++ b/mm/kasan/init.c
@@ -250,20 +250,9 @@ int __ref kasan_populate_early_shadow(const void *shadow_start,
 			 * 3,2 - level page tables where we don't have
 			 * puds,pmds, so pgd_populate(), pud_populate()
 			 * is noops.
-			 *
-			 * The ifndef is required to avoid build breakage.
-			 *
-			 * With 5level-fixup.h, pgd_populate() is not nop and
-			 * we reference kasan_early_shadow_p4d. It's not defined
-			 * unless 5-level paging enabled.
-			 *
-			 * The ifndef can be dropped once all KASAN-enabled
-			 * architectures will switch to pgtable-nop4d.h.
 			 */
-#ifndef __ARCH_HAS_5LEVEL_HACK
 			pgd_populate(&init_mm, pgd,
 					lm_alias(kasan_early_shadow_p4d));
-#endif
 			p4d = p4d_offset(pgd, addr);
 			p4d_populate(&init_mm, p4d,
 					lm_alias(kasan_early_shadow_pud));
diff --git a/mm/ksm.c b/mm/ksm.c
index 281c00129a2e..18c5d005bd01 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -612,7 +612,7 @@ static struct stable_node *alloc_stable_node_chain(struct stable_node *dup,
 		 * Move the old stable node to the second dimension
 		 * queued in the hlist_dup. The invariant is that all
 		 * dup stable_nodes in the chain->hlist point to pages
-		 * that are wrprotected and have the exact same
+		 * that are write protected and have the exact same
 		 * content.
 		 */
 		stable_node_chain_add_dup(dup, chain);
@@ -1148,7 +1148,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
 
 	/*
 	 * No need to check ksm_use_zero_pages here: we can only have a
-	 * zero_page here if ksm_use_zero_pages was enabled alreaady.
+	 * zero_page here if ksm_use_zero_pages was enabled already.
 	 */
 	if (!is_zero_pfn(page_to_pfn(kpage))) {
 		get_page(kpage);
@@ -1608,7 +1608,7 @@ again:
 			 * continue. All KSM pages belonging to the
 			 * stable_node dups in a stable_node chain
 			 * have the same content and they're
-			 * wrprotected at all times. Any will work
+			 * write protected at all times. Any will work
 			 * fine to continue the walk.
 			 */
 			tree_page = get_ksm_page(stable_node_any,
@@ -1843,7 +1843,7 @@ again:
 			 * continue. All KSM pages belonging to the
 			 * stable_node dups in a stable_node chain
 			 * have the same content and they're
-			 * wrprotected at all times. Any will work
+			 * write protected at all times. Any will work
 			 * fine to continue the walk.
 			 */
 			tree_page = get_ksm_page(stable_node_any,
@@ -2001,7 +2001,7 @@ static void stable_tree_append(struct rmap_item *rmap_item,
 	 * duplicate. page_migration could break later if rmap breaks,
 	 * so we can as well crash here. We really need to check for
 	 * rmap_hlist_len == STABLE_NODE_CHAIN, but we can as well check
-	 * for other negative values as an undeflow if detected here
+	 * for other negative values as an underflow if detected here
 	 * for the first time (and not when decreasing rmap_hlist_len)
 	 * would be sign of memory corruption in the stable_node.
 	 */
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 4d5294c39bba..9222910ab1cb 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -213,7 +213,7 @@ restart:
 
 		/*
 		 * decrement nr_to_walk first so that we don't livelock if we
-		 * get stuck on large numbesr of LRU_RETRY items
+		 * get stuck on large numbers of LRU_RETRY items
 		 */
 		if (!*nr_to_walk)
 			break;
diff --git a/mm/memblock.c b/mm/memblock.c
index 743659d88fc4..39aceafc57f6 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -78,7 +78,7 @@
  * * memblock_alloc*() - these functions return the **virtual** address
  *   of the allocated memory.
  *
- * Note, that both API variants use implict assumptions about allowed
+ * Note, that both API variants use implicit assumptions about allowed
  * memory ranges and the fallback methods. Consult the documentation
  * of memblock_alloc_internal() and memblock_alloc_range_nid()
  * functions for more elaborate description.
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5381afb23d58..3dde78f5b918 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3186,7 +3186,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
  * Test whether @memcg has children, dead or alive.  Note that this
  * function doesn't care whether @memcg has use_hierarchy enabled and
  * returns %true if there are child csses according to the cgroup
- * hierarchy.  Testing use_hierarchy is the caller's responsiblity.
+ * hierarchy.  Testing use_hierarchy is the caller's responsibility.
  */
 static inline bool memcg_has_children(struct mem_cgroup *memcg)
 {
@@ -4838,7 +4838,7 @@ static struct cftype mem_cgroup_legacy_files[] = {
  * limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of
  * memory-controlled cgroups to 64k.
  *
- * However, there usually are many references to the oflline CSS after
+ * However, there usually are many references to the offline CSS after
  * the cgroup has been destroyed, such as page cache or reclaimable
  * slab objects, that don't need to hang on to the ID. We want to keep
  * those dead CSS from occupying IDs, or we might quickly exhaust the
diff --git a/mm/memory.c b/mm/memory.c
index 7b70398f76a0..d97e8848892d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2467,7 +2467,7 @@ static inline bool cow_user_page(struct page *dst, struct page *src,
 		}
 
 		/*
-		 * The same page can be mapped back since last copy attampt.
+		 * The same page can be mapped back since last copy attempt.
 		 * Try to copy again under PTL.
 		 */
 		if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE)) {
@@ -4436,19 +4436,11 @@ int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address)
 	smp_wmb(); /* See comment in __pte_alloc */
 
 	spin_lock(&mm->page_table_lock);
-#ifndef __ARCH_HAS_5LEVEL_HACK
 	if (!p4d_present(*p4d)) {
 		mm_inc_nr_puds(mm);
 		p4d_populate(mm, p4d, new);
 	} else	/* Another has populated it */
 		pud_free(mm, new);
-#else
-	if (!pgd_present(*p4d)) {
-		mm_inc_nr_puds(mm);
-		pgd_populate(mm, p4d, new);
-	} else	/* Another has populated it */
-		pud_free(mm, new);
-#endif /* __ARCH_HAS_5LEVEL_HACK */
 	spin_unlock(&mm->page_table_lock);
 	return 0;
 }
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 926ec704e835..c4d5c45820d0 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -98,11 +98,14 @@ void mem_hotplug_done(void)
 u64 max_mem_size = U64_MAX;
 
 /* add this memory to iomem resource */
-static struct resource *register_memory_resource(u64 start, u64 size)
+static struct resource *register_memory_resource(u64 start, u64 size,
+						 const char *resource_name)
 {
 	struct resource *res;
 	unsigned long flags =  IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
-	char *resource_name = "System RAM";
+
+	if (strcmp(resource_name, "System RAM"))
+		flags |= IORESOURCE_MEM_DRIVER_MANAGED;
 
 	/*
 	 * Make sure value parsed from 'mem=' only restricts memory adding
@@ -862,10 +865,9 @@ static void reset_node_present_pages(pg_data_t *pgdat)
 }
 
 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
-static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
+static pg_data_t __ref *hotadd_new_pgdat(int nid)
 {
 	struct pglist_data *pgdat;
-	unsigned long start_pfn = PFN_DOWN(start);
 
 	pgdat = NODE_DATA(nid);
 	if (!pgdat) {
@@ -895,9 +897,8 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
 	}
 
 	/* we can use NODE_DATA(nid) from here */
-
 	pgdat->node_id = nid;
-	pgdat->node_start_pfn = start_pfn;
+	pgdat->node_start_pfn = 0;
 
 	/* init node's zones as empty zones, we don't have any present pages.*/
 	free_area_init_core_hotplug(nid);
@@ -932,7 +933,6 @@ static void rollback_node_hotadd(int nid)
 /**
  * try_online_node - online a node if offlined
  * @nid: the node ID
- * @start: start addr of the node
  * @set_node_online: Whether we want to online the node
  * called by cpu_up() to online a node without onlined memory.
  *
@@ -941,7 +941,7 @@ static void rollback_node_hotadd(int nid)
  * 0 -> the node is already online
  * -ENOMEM -> the node could not be allocated
  */
-static int __try_online_node(int nid, u64 start, bool set_node_online)
+static int __try_online_node(int nid, bool set_node_online)
 {
 	pg_data_t *pgdat;
 	int ret = 1;
@@ -949,7 +949,7 @@ static int __try_online_node(int nid, u64 start, bool set_node_online)
 	if (node_online(nid))
 		return 0;
 
-	pgdat = hotadd_new_pgdat(nid, start);
+	pgdat = hotadd_new_pgdat(nid);
 	if (!pgdat) {
 		pr_err("Cannot online node %d due to NULL pgdat\n", nid);
 		ret = -ENOMEM;
@@ -973,7 +973,7 @@ int try_online_node(int nid)
 	int ret;
 
 	mem_hotplug_begin();
-	ret =  __try_online_node(nid, 0, true);
+	ret =  __try_online_node(nid, true);
 	mem_hotplug_done();
 	return ret;
 }
@@ -1017,17 +1017,17 @@ int __ref add_memory_resource(int nid, struct resource *res)
 	if (ret)
 		return ret;
 
+	if (!node_possible(nid)) {
+		WARN(1, "node %d was absent from the node_possible_map\n", nid);
+		return -EINVAL;
+	}
+
 	mem_hotplug_begin();
 
-	/*
-	 * Add new range to memblock so that when hotadd_new_pgdat() is called
-	 * to allocate new pgdat, get_pfn_range_for_nid() will be able to find
-	 * this new range and calculate total pages correctly.  The range will
-	 * be removed at hot-remove time.
-	 */
-	memblock_add_node(start, size, nid);
+	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
+		memblock_add_node(start, size, nid);
 
-	ret = __try_online_node(nid, start, false);
+	ret = __try_online_node(nid, false);
 	if (ret < 0)
 		goto error;
 	new_node = ret;
@@ -1060,7 +1060,8 @@ int __ref add_memory_resource(int nid, struct resource *res)
 	BUG_ON(ret);
 
 	/* create new memmap entry */
-	firmware_map_add_hotplug(start, start + size, "System RAM");
+	if (!strcmp(res->name, "System RAM"))
+		firmware_map_add_hotplug(start, start + size, "System RAM");
 
 	/* device_online() will take the lock when calling online_pages() */
 	mem_hotplug_done();
@@ -1074,7 +1075,8 @@ error:
 	/* rollback pgdat allocation and others */
 	if (new_node)
 		rollback_node_hotadd(nid);
-	memblock_remove(start, size);
+	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
+		memblock_remove(start, size);
 	mem_hotplug_done();
 	return ret;
 }
@@ -1085,7 +1087,7 @@ int __ref __add_memory(int nid, u64 start, u64 size)
 	struct resource *res;
 	int ret;
 
-	res = register_memory_resource(start, size);
+	res = register_memory_resource(start, size, "System RAM");
 	if (IS_ERR(res))
 		return PTR_ERR(res);
 
@@ -1107,82 +1109,57 @@ int add_memory(int nid, u64 start, u64 size)
 }
 EXPORT_SYMBOL_GPL(add_memory);
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 /*
- * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
- * set and the size of the free page is given by page_order(). Using this,
- * the function determines if the pageblock contains only free pages.
- * Due to buddy contraints, a free page at least the size of a pageblock will
- * be located at the start of the pageblock
+ * Add special, driver-managed memory to the system as system RAM. Such
+ * memory is not exposed via the raw firmware-provided memmap as system
+ * RAM, instead, it is detected and added by a driver - during cold boot,
+ * after a reboot, and after kexec.
+ *
+ * Reasons why this memory should not be used for the initial memmap of a
+ * kexec kernel or for placing kexec images:
+ * - The booting kernel is in charge of determining how this memory will be
+ *   used (e.g., use persistent memory as system RAM)
+ * - Coordination with a hypervisor is required before this memory
+ *   can be used (e.g., inaccessible parts).
+ *
+ * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided
+ * memory map") are created. Also, the created memory resource is flagged
+ * with IORESOURCE_MEM_DRIVER_MANAGED, so in-kernel users can special-case
+ * this memory as well (esp., not place kexec images onto it).
+ *
+ * The resource_name (visible via /proc/iomem) has to have the format
+ * "System RAM ($DRIVER)".
  */
-static inline int pageblock_free(struct page *page)
+int add_memory_driver_managed(int nid, u64 start, u64 size,
+			      const char *resource_name)
 {
-	return PageBuddy(page) && page_order(page) >= pageblock_order;
-}
+	struct resource *res;
+	int rc;
 
-/* Return the pfn of the start of the next active pageblock after a given pfn */
-static unsigned long next_active_pageblock(unsigned long pfn)
-{
-	struct page *page = pfn_to_page(pfn);
+	if (!resource_name ||
+	    strstr(resource_name, "System RAM (") != resource_name ||
+	    resource_name[strlen(resource_name) - 1] != ')')
+		return -EINVAL;
 
-	/* Ensure the starting page is pageblock-aligned */
-	BUG_ON(pfn & (pageblock_nr_pages - 1));
+	lock_device_hotplug();
 
-	/* If the entire pageblock is free, move to the end of free page */
-	if (pageblock_free(page)) {
-		int order;
-		/* be careful. we don't have locks, page_order can be changed.*/
-		order = page_order(page);
-		if ((order < MAX_ORDER) && (order >= pageblock_order))
-			return pfn + (1 << order);
+	res = register_memory_resource(start, size, resource_name);
+	if (IS_ERR(res)) {
+		rc = PTR_ERR(res);
+		goto out_unlock;
 	}
 
-	return pfn + pageblock_nr_pages;
-}
-
-static bool is_pageblock_removable_nolock(unsigned long pfn)
-{
-	struct page *page = pfn_to_page(pfn);
-	struct zone *zone;
-
-	/*
-	 * We have to be careful here because we are iterating over memory
-	 * sections which are not zone aware so we might end up outside of
-	 * the zone but still within the section.
-	 * We have to take care about the node as well. If the node is offline
-	 * its NODE_DATA will be NULL - see page_zone.
-	 */
-	if (!node_online(page_to_nid(page)))
-		return false;
-
-	zone = page_zone(page);
-	pfn = page_to_pfn(page);
-	if (!zone_spans_pfn(zone, pfn))
-		return false;
-
-	return !has_unmovable_pages(zone, page, MIGRATE_MOVABLE,
-				    MEMORY_OFFLINE);
-}
-
-/* Checks if this range of memory is likely to be hot-removable. */
-bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
-{
-	unsigned long end_pfn, pfn;
-
-	end_pfn = min(start_pfn + nr_pages,
-			zone_end_pfn(page_zone(pfn_to_page(start_pfn))));
-
-	/* Check the starting page of each pageblock within the range */
-	for (pfn = start_pfn; pfn < end_pfn; pfn = next_active_pageblock(pfn)) {
-		if (!is_pageblock_removable_nolock(pfn))
-			return false;
-		cond_resched();
-	}
+	rc = add_memory_resource(nid, res);
+	if (rc < 0)
+		release_memory_resource(res);
 
-	/* All pageblocks in the memory block are likely to be hot-removable */
-	return true;
+out_unlock:
+	unlock_device_hotplug();
+	return rc;
 }
+EXPORT_SYMBOL_GPL(add_memory_driver_managed);
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
 /*
  * Confirm all pages in a range [start, end) belong to the same zone (skipping
  * memory holes). When true, return the zone.
@@ -1360,7 +1337,7 @@ offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
 }
 
 /*
- * Check all pages in range, recoreded as memory resource, are isolated.
+ * Check all pages in range, recorded as memory resource, are isolated.
  */
 static int
 check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
@@ -1746,8 +1723,12 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size)
 	mem_hotplug_begin();
 
 	arch_remove_memory(nid, start, size, NULL);
-	memblock_free(start, size);
-	memblock_remove(start, size);
+
+	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
+		memblock_free(start, size);
+		memblock_remove(start, size);
+	}
+
 	__release_memory_resource(start, size);
 
 	try_offline_node(nid);
diff --git a/mm/mmap.c b/mm/mmap.c
index f609e9ec4a25..39bd60c20a82 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1207,7 +1207,7 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
 }
 
 /*
- * Rough compatbility check to quickly see if it's even worth looking
+ * Rough compatibility check to quickly see if it's even worth looking
  * at sharing an anon_vma.
  *
  * They need to have the same vm_file, and the flags can only differ
diff --git a/mm/mremap.c b/mm/mremap.c
index 57b1f999f789..7d69e3fe51aa 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -785,7 +785,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 out:
 	if (offset_in_page(ret)) {
 		vm_unacct_memory(charged);
-		locked = 0;
+		locked = false;
 	}
 	if (downgraded)
 		up_read(&current->mm->mmap_sem);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index d79ed1f88c7a..28b3e7a67565 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -257,7 +257,7 @@ static void wb_min_max_ratio(struct bdi_writeback *wb,
  * requiring writeback.
  *
  * This number of dirtyable pages is the base value of which the
- * user-configurable dirty ratio is the effictive number of pages that
+ * user-configurable dirty ratio is the effective number of pages that
  * are allowed to be actually dirtied.  Per individual zone, or
  * globally by using the sum of dirtyable pages over all zones.
  *
diff --git a/mm/slub.c b/mm/slub.c
index d52487919278..b8f798b50d44 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2013,7 +2013,7 @@ static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
 
 #ifdef CONFIG_PREEMPTION
 /*
- * Calculate the next globally unique transaction for disambiguiation
+ * Calculate the next globally unique transaction for disambiguation
  * during cmpxchg. The transactions start with the cpu number and are then
  * incremented by CONFIG_NR_CPUS.
  */
diff --git a/mm/sparse.c b/mm/sparse.c
index 1aee5a481571..6284328cd9f2 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -288,7 +288,7 @@ void __init memory_present(int nid, unsigned long start, unsigned long end)
 
 /*
  * Mark all memblocks as present using memory_present(). This is a
- * convienence function that is useful for a number of arches
+ * convenience function that is useful for a number of arches
  * to mark all of the systems memory as present during initialization.
  */
 void __init memblocks_present(void)
diff --git a/mm/util.c b/mm/util.c
index 41b47d8cae09..cd62e6fb5318 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -604,6 +604,24 @@ void kvfree(const void *addr)
 }
 EXPORT_SYMBOL(kvfree);
 
+/**
+ * kvfree_sensitive - Free a data object containing sensitive information.
+ * @addr: address of the data object to be freed.
+ * @len: length of the data object.
+ *
+ * Use the special memzero_explicit() function to clear the content of a
+ * kvmalloc'ed object containing sensitive data to make sure that the
+ * compiler won't optimize out the data clearing.
+ */
+void kvfree_sensitive(const void *addr, size_t len)
+{
+	if (likely(!ZERO_OR_NULL_PTR(addr))) {
+		memzero_explicit((void *)addr, len);
+		kvfree(addr);
+	}
+}
+EXPORT_SYMBOL(kvfree_sensitive);
+
 static inline void *__page_rmapping(struct page *page)
 {
 	unsigned long mapping;
@@ -796,10 +814,6 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
 {
 	long allowed;
 
-	VM_WARN_ONCE(percpu_counter_read(&vm_committed_as) <
-			-(s64)vm_committed_as_batch * num_online_cpus(),
-			"memory commitment underflow");
-
 	vm_acct_memory(pages);
 
 	/*
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1e94497b7388..3091c2ca60df 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2317,7 +2317,7 @@ static inline void __vfree_deferred(const void *addr)
 	 * Use raw_cpu_ptr() because this can be called from preemptible
 	 * context. Preemption is absolutely fine here, because the llist_add()
 	 * implementation is lockless, so it works even if we are adding to
-	 * nother cpu's list.  schedule_work() should be fine with this too.
+	 * another cpu's list. schedule_work() should be fine with this too.
 	 */
 	struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 3792dd19788c..b6d84326bdf2 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -682,7 +682,7 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
 		freed += ret;
 		/*
 		 * Bail out if someone want to register a new shrinker to
-		 * prevent the regsitration from being stalled for long periods
+		 * prevent the registration from being stalled for long periods
 		 * by parallel ongoing shrinking.
 		 */
 		if (rwsem_is_contended(&shrinker_rwsem)) {
@@ -1613,7 +1613,7 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode)
 
 /*
  * Update LRU sizes after isolating pages. The LRU size updates must
- * be complete before mem_cgroup_update_lru_size due to a santity check.
+ * be complete before mem_cgroup_update_lru_size due to a sanity check.
  */
 static __always_inline void update_lru_sizes(struct lruvec *lruvec,
 			enum lru_list lru, unsigned long *nr_zone_taken)
@@ -2371,7 +2371,7 @@ out:
 
 			/*
 			 * Minimally target SWAP_CLUSTER_MAX pages to keep
-			 * reclaim moving forwards, avoiding decremeting
+			 * reclaim moving forwards, avoiding decrementing
 			 * sc->priority further than desirable.
 			 */
 			scan = max(scan, SWAP_CLUSTER_MAX);
diff --git a/mm/vmstat.c b/mm/vmstat.c
index a7db29f7e5f7..3fb23a21f6dd 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -2069,24 +2069,14 @@ static int unusable_show(struct seq_file *m, void *arg)
 	return 0;
 }
 
-static const struct seq_operations unusable_op = {
+static const struct seq_operations unusable_sops = {
 	.start	= frag_start,
 	.next	= frag_next,
 	.stop	= frag_stop,
 	.show	= unusable_show,
 };
 
-static int unusable_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &unusable_op);
-}
-
-static const struct file_operations unusable_file_ops = {
-	.open		= unusable_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
+DEFINE_SEQ_ATTRIBUTE(unusable);
 
 static void extfrag_show_print(struct seq_file *m,
 					pg_data_t *pgdat, struct zone *zone)
@@ -2121,24 +2111,14 @@ static int extfrag_show(struct seq_file *m, void *arg)
 	return 0;
 }
 
-static const struct seq_operations extfrag_op = {
+static const struct seq_operations extfrag_sops = {
 	.start	= frag_start,
 	.next	= frag_next,
 	.stop	= frag_stop,
 	.show	= extfrag_show,
 };
 
-static int extfrag_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &extfrag_op);
-}
-
-static const struct file_operations extfrag_file_ops = {
-	.open		= extfrag_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
+DEFINE_SEQ_ATTRIBUTE(extfrag);
 
 static int __init extfrag_debug_init(void)
 {
@@ -2147,10 +2127,10 @@ static int __init extfrag_debug_init(void)
 	extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
 
 	debugfs_create_file("unusable_index", 0444, extfrag_debug_root, NULL,
-			    &unusable_file_ops);
+			    &unusable_fops);
 
 	debugfs_create_file("extfrag_index", 0444, extfrag_debug_root, NULL,
-			    &extfrag_file_ops);
+			    &extfrag_fops);
 
 	return 0;
 }
diff --git a/mm/zbud.c b/mm/zbud.c
index de5dd4ddaa82..bc93aa4e46fc 100644
--- a/mm/zbud.c
+++ b/mm/zbud.c
@@ -243,7 +243,7 @@ static struct zbud_header *init_zbud_page(struct page *page)
 	zhdr->last_chunks = 0;
 	INIT_LIST_HEAD(&zhdr->buddy);
 	INIT_LIST_HEAD(&zhdr->lru);
-	zhdr->under_reclaim = 0;
+	zhdr->under_reclaim = false;
 	return zhdr;
 }