Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...

6 files changed, 12 insertions, 112 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e5bcb4995268..d58133f49188 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -71,6 +71,7 @@ config ARM64
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select ARCH_USE_SYM_ANNOTATIONS
+	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
 	select ARCH_SUPPORTS_MEMORY_FAILURE
 	select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
 	select ARCH_SUPPORTS_ATOMIC_RMW
@@ -125,6 +126,7 @@ config ARM64
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_MOVE_PMD
+	select HAVE_MOVE_PUD
 	select HAVE_PCI
 	select HAVE_ACPI_APEI if (ACPI && EFI)
 	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
@@ -139,6 +141,7 @@ config ARM64
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_MMAP_RND_BITS
 	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
+	select HAVE_ARCH_PFN_VALID
 	select HAVE_ARCH_PREL32_RELOCATIONS
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_STACKLEAK
@@ -1027,9 +1030,6 @@ config HOLES_IN_ZONE
 
 source "kernel/Kconfig.hz"
 
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
-	def_bool y
-
 config ARCH_SPARSEMEM_ENABLE
 	def_bool y
 	select SPARSEMEM_VMEMMAP_ENABLE
@@ -1043,9 +1043,6 @@ config ARCH_SELECT_MEMORY_MODEL
 config ARCH_FLATMEM_ENABLE
 	def_bool !NUMA
 
-config HAVE_ARCH_PFN_VALID
-	def_bool y
-
 config HW_PERF_EVENTS
 	def_bool y
 	depends on ARM_PMU
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index 9384fd8fc13c..45217f21f1fe 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -140,6 +140,7 @@ int set_memory_valid(unsigned long addr, int numpages, int enable);
 
 int set_direct_map_invalid_noflush(struct page *page);
 int set_direct_map_default_noflush(struct page *page);
+bool kernel_page_present(struct page *page);
 
 #include <asm-generic/cacheflush.h>
 
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 88a18d7f4e59..501562793ce2 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -463,6 +463,7 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd)
 #define pfn_pud(pfn,prot)	__pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
 
 #define set_pmd_at(mm, addr, pmdp, pmd)	set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
+#define set_pud_at(mm, addr, pudp, pud)	set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud))
 
 #define __p4d_to_phys(p4d)	__pte_to_phys(p4d_pte(p4d))
 #define __phys_to_p4d_val(phys)	__phys_to_pte_val(phys)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index debb8995d57f..cee5d04ea9ad 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -78,17 +78,9 @@ static union {
 } vdso_data_store __page_aligned_data;
 struct vdso_data *vdso_data = vdso_data_store.data;
 
-static int __vdso_remap(enum vdso_abi abi,
-			const struct vm_special_mapping *sm,
-			struct vm_area_struct *new_vma)
+static int vdso_mremap(const struct vm_special_mapping *sm,
+		struct vm_area_struct *new_vma)
 {
-	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
-	unsigned long vdso_size = vdso_info[abi].vdso_code_end -
-				  vdso_info[abi].vdso_code_start;
-
-	if (vdso_size != new_size)
-		return -EINVAL;
-
 	current->mm->context.vdso = (void *)new_vma->vm_start;
 
 	return 0;
@@ -219,17 +211,6 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	return vmf_insert_pfn(vma, vmf->address, pfn);
 }
 
-static int vvar_mremap(const struct vm_special_mapping *sm,
-		       struct vm_area_struct *new_vma)
-{
-	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
-
-	if (new_size != VVAR_NR_PAGES * PAGE_SIZE)
-		return -EINVAL;
-
-	return 0;
-}
-
 static int __setup_additional_pages(enum vdso_abi abi,
 				    struct mm_struct *mm,
 				    struct linux_binprm *bprm,
@@ -280,12 +261,6 @@ up_fail:
 /*
  * Create and map the vectors page for AArch32 tasks.
  */
-static int aarch32_vdso_mremap(const struct vm_special_mapping *sm,
-		struct vm_area_struct *new_vma)
-{
-	return __vdso_remap(VDSO_ABI_AA32, sm, new_vma);
-}
-
 enum aarch32_map {
 	AA32_MAP_VECTORS, /* kuser helpers */
 	AA32_MAP_SIGPAGE,
@@ -308,11 +283,10 @@ static struct vm_special_mapping aarch32_vdso_maps[] = {
 	[AA32_MAP_VVAR] = {
 		.name = "[vvar]",
 		.fault = vvar_fault,
-		.mremap = vvar_mremap,
 	},
 	[AA32_MAP_VDSO] = {
 		.name = "[vdso]",
-		.mremap = aarch32_vdso_mremap,
+		.mremap = vdso_mremap,
 	},
 };
 
@@ -453,12 +427,6 @@ out:
 }
 #endif /* CONFIG_COMPAT */
 
-static int vdso_mremap(const struct vm_special_mapping *sm,
-		struct vm_area_struct *new_vma)
-{
-	return __vdso_remap(VDSO_ABI_AA64, sm, new_vma);
-}
-
 enum aarch64_map {
 	AA64_MAP_VVAR,
 	AA64_MAP_VDSO,
@@ -468,7 +436,6 @@ static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = {
 	[AA64_MAP_VVAR] = {
 		.name	= "[vvar]",
 		.fault = vvar_fault,
-		.mremap = vvar_mremap,
 	},
 	[AA64_MAP_VDSO] = {
 		.name	= "[vdso]",
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index fbd452e12397..69d4251ee079 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -444,71 +444,6 @@ void __init bootmem_init(void)
 	memblock_dump_all();
 }
 
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
-static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
-{
-	struct page *start_pg, *end_pg;
-	unsigned long pg, pgend;
-
-	/*
-	 * Convert start_pfn/end_pfn to a struct page pointer.
-	 */
-	start_pg = pfn_to_page(start_pfn - 1) + 1;
-	end_pg = pfn_to_page(end_pfn - 1) + 1;
-
-	/*
-	 * Convert to physical addresses, and round start upwards and end
-	 * downwards.
-	 */
-	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
-	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
-
-	/*
-	 * If there are free pages between these, free the section of the
-	 * memmap array.
-	 */
-	if (pg < pgend)
-		memblock_free(pg, pgend - pg);
-}
-
-/*
- * The mem_map array can get very big. Free the unused area of the memory map.
- */
-static void __init free_unused_memmap(void)
-{
-	unsigned long start, end, prev_end = 0;
-	int i;
-
-	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
-#ifdef CONFIG_SPARSEMEM
-		/*
-		 * Take care not to free memmap entries that don't exist due
-		 * to SPARSEMEM sections which aren't present.
-		 */
-		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
-#endif
-		/*
-		 * If we had a previous bank, and there is a space between the
-		 * current bank and the previous, free it.
-		 */
-		if (prev_end && prev_end < start)
-			free_memmap(prev_end, start);
-
-		/*
-		 * Align up here since the VM subsystem insists that the
-		 * memmap entries are valid from the bank end aligned to
-		 * MAX_ORDER_NR_PAGES.
-		 */
-		prev_end = ALIGN(end, MAX_ORDER_NR_PAGES);
-	}
-
-#ifdef CONFIG_SPARSEMEM
-	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
-		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
-#endif
-}
-#endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
-
 /*
  * mem_init() marks the free areas in the mem_map and tells us how much memory
  * is free.  This is done after various parts of the system have claimed their
@@ -524,9 +459,6 @@ void __init mem_init(void)
 
 	set_max_mapnr(max_pfn - PHYS_PFN_OFFSET);
 
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
-	free_unused_memmap();
-#endif
 	/* this will put all unused low memory onto the freelists */
 	memblock_free_all();
 
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 1b94f5b82654..92eccaf595c8 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -155,7 +155,7 @@ int set_direct_map_invalid_noflush(struct page *page)
 		.clear_mask = __pgprot(PTE_VALID),
 	};
 
-	if (!rodata_full)
+	if (!debug_pagealloc_enabled() && !rodata_full)
 		return 0;
 
 	return apply_to_page_range(&init_mm,
@@ -170,7 +170,7 @@ int set_direct_map_default_noflush(struct page *page)
 		.clear_mask = __pgprot(PTE_RDONLY),
 	};
 
-	if (!rodata_full)
+	if (!debug_pagealloc_enabled() && !rodata_full)
 		return 0;
 
 	return apply_to_page_range(&init_mm,
@@ -178,6 +178,7 @@ int set_direct_map_default_noflush(struct page *page)
 				   PAGE_SIZE, change_page_range, &data);
 }
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
 void __kernel_map_pages(struct page *page, int numpages, int enable)
 {
 	if (!debug_pagealloc_enabled() && !rodata_full)
@@ -185,6 +186,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
 
 	set_memory_valid((unsigned long)page_address(page), numpages, enable);
 }
+#endif /* CONFIG_DEBUG_PAGEALLOC */
 
 /*
  * This function is used to determine if a linear map page has been marked as