Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "18 patches.

  Subsystems affected by this patch series: mm (pagealloc, memcg, kasan,
  memory-failure, and highmem), ubsan, proc, and MAINTAINERS"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  MAINTAINERS: add a couple more files to the Clang/LLVM section
  proc_sysctl: fix oops caused by incorrect command parameters
  powerpc/mm/highmem: use __set_pte_at() for kmap_local()
  mips/mm/highmem: use set_pte() for kmap_local()
  mm/highmem: prepare for overriding set_pte_at()
  sparc/mm/highmem: flush cache and TLB
  mm: fix page reference leak in soft_offline_page()
  ubsan: disable unsigned-overflow check for i386
  kasan, mm: fix resetting page_alloc tags for HW_TAGS
  kasan, mm: fix conflicts with init_on_alloc/free
  kasan: fix HW_TAGS boot parameters
  kasan: fix incorrect arguments passing in kasan_add_zero_shadow
  kasan: fix unaligned address is unhandled in kasan_remove_zero_shadow
  mm: fix numa stats for thp migration
  mm: memcg: fix memcg file_dirty numa stat
  mm: memcg/slab: optimize objcg stock draining
  mm: fix initialization of struct page for holes in memory layout
  x86/setup: don't remove E820_TYPE_RAM for pfn 0

Documentation/dev-tools/kasan.rst

@@ -160,29 +160,14 @@ intended for use in production as a security mitigation. Therefore it supports
 boot parameters that allow to disable KASAN competely or otherwise control
 particular KASAN features.
 
-The things that can be controlled are:
+- ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
 
-1. Whether KASAN is enabled at all.
-2. Whether KASAN collects and saves alloc/free stacks.
-3. Whether KASAN panics on a detected bug or not.
+- ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
+  traces collection (default: ``on`` for ``CONFIG_DEBUG_KERNEL=y``, otherwise
+  ``off``).
 
-The ``kasan.mode`` boot parameter allows to choose one of three main modes:
-
-- ``kasan.mode=off`` - KASAN is disabled, no tag checks are performed
-- ``kasan.mode=prod`` - only essential production features are enabled
-- ``kasan.mode=full`` - all KASAN features are enabled
-
-The chosen mode provides default control values for the features mentioned
-above. However it's also possible to override the default values by providing:
-
-- ``kasan.stacktrace=off`` or ``=on`` - enable alloc/free stack collection
-					(default: ``on`` for ``mode=full``,
-					 otherwise ``off``)
-- ``kasan.fault=report`` or ``=panic`` - only print KASAN report or also panic
-					 (default: ``report``)
-
-If ``kasan.mode`` parameter is not provided, it defaults to ``full`` when
-``CONFIG_DEBUG_KERNEL`` is enabled, and to ``prod`` otherwise.
+- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
+  report or also panic the kernel (default: ``report``).
 
 For developers
 ~~~~~~~~~~~~~~

MAINTAINERS

@@ -4311,7 +4311,9 @@ W:	https://clangbuiltlinux.github.io/
 B:	https://github.com/ClangBuiltLinux/linux/issues
 C:	irc://chat.freenode.net/clangbuiltlinux
 F:	Documentation/kbuild/llvm.rst
+F:	include/linux/compiler-clang.h
 F:	scripts/clang-tools/
+F:	scripts/clang-version.sh
 F:	scripts/lld-version.sh
 K:	\b(?i:clang|llvm)\b
 

arch/mips/include/asm/highmem.h

@@ -51,6 +51,7 @@ extern void kmap_flush_tlb(unsigned long addr);
 
 #define flush_cache_kmaps()	BUG_ON(cpu_has_dc_aliases)
 
+#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev)	set_pte(ptep, ptev)
 #define arch_kmap_local_post_map(vaddr, pteval)	local_flush_tlb_one(vaddr)
 #define arch_kmap_local_post_unmap(vaddr)	local_flush_tlb_one(vaddr)
 

arch/powerpc/include/asm/highmem.h

@@ -58,6 +58,8 @@ extern pte_t *pkmap_page_table;
 
 #define flush_cache_kmaps()	flush_cache_all()
 
+#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev)	\
+	__set_pte_at(mm, vaddr, ptep, ptev, 1)
 #define arch_kmap_local_post_map(vaddr, pteval)	\
 	local_flush_tlb_page(NULL, vaddr)
 #define arch_kmap_local_post_unmap(vaddr)	\

arch/sparc/include/asm/highmem.h

@@ -50,10 +50,11 @@ extern pte_t *pkmap_page_table;
 
 #define flush_cache_kmaps()	flush_cache_all()
 
-/* FIXME: Use __flush_tlb_one(vaddr) instead of flush_cache_all() -- Anton */
-#define arch_kmap_local_post_map(vaddr, pteval)	flush_cache_all()
-#define arch_kmap_local_post_unmap(vaddr)	flush_cache_all()
-
+/* FIXME: Use __flush_*_one(vaddr) instead of flush_*_all() -- Anton */
+#define arch_kmap_local_pre_map(vaddr, pteval)	flush_cache_all()
+#define arch_kmap_local_pre_unmap(vaddr)	flush_cache_all()
+#define arch_kmap_local_post_map(vaddr, pteval)	flush_tlb_all()
+#define arch_kmap_local_post_unmap(vaddr)	flush_tlb_all()
 
 #endif /* __KERNEL__ */
 

arch/x86/kernel/setup.c

@@ -660,17 +660,6 @@ static void __init trim_platform_memory_ranges(void)
 
 static void __init trim_bios_range(void)
 {
-	/*
-	 * A special case is the first 4Kb of memory;
-	 * This is a BIOS owned area, not kernel ram, but generally
-	 * not listed as such in the E820 table.
-	 *
-	 * This typically reserves additional memory (64KiB by default)
-	 * since some BIOSes are known to corrupt low memory.  See the
-	 * Kconfig help text for X86_RESERVE_LOW.
-	 */
-	e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
-
 	/*
 	 * special case: Some BIOSes report the PC BIOS
 	 * area (640Kb -> 1Mb) as RAM even though it is not.
@@ -728,6 +717,15 @@ early_param("reservelow", parse_reservelow);
 
 static void __init trim_low_memory_range(void)
 {
+	/*
+	 * A special case is the first 4Kb of memory;
+	 * This is a BIOS owned area, not kernel ram, but generally
+	 * not listed as such in the E820 table.
+	 *
+	 * This typically reserves additional memory (64KiB by default)
+	 * since some BIOSes are known to corrupt low memory.  See the
+	 * Kconfig help text for X86_RESERVE_LOW.
+	 */
 	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
 }
 	

fs/proc/proc_sysctl.c

@@ -1770,6 +1770,12 @@ static int process_sysctl_arg(char *param, char *val,
 			return 0;
 	}
 
+	if (!val)
+		return -EINVAL;
+	len = strlen(val);
+	if (len == 0)
+		return -EINVAL;
+
 	/*
 	 * To set sysctl options, we use a temporary mount of proc, look up the
 	 * respective sys/ file and write to it. To avoid mounting it when no
@@ -1811,7 +1817,6 @@ static int process_sysctl_arg(char *param, char *val,
 				file, param, val);
 		goto out;
 	}
-	len = strlen(val);
 	wret = kernel_write(file, val, len, &pos);
 	if (wret < 0) {
 		err = wret;

lib/Kconfig.ubsan

@@ -123,6 +123,7 @@ config UBSAN_SIGNED_OVERFLOW
 config UBSAN_UNSIGNED_OVERFLOW
 	bool "Perform checking for unsigned arithmetic overflow"
 	depends on $(cc-option,-fsanitize=unsigned-integer-overflow)
+	depends on !X86_32 # avoid excessive stack usage on x86-32/clang
 	help
 	  This option enables -fsanitize=unsigned-integer-overflow which checks
 	  for overflow of any arithmetic operations with unsigned integers. This

mm/highmem.c

@@ -473,6 +473,11 @@ static inline void *arch_kmap_local_high_get(struct page *page)
 }
 #endif
 
+#ifndef arch_kmap_local_set_pte
+#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev)	\
+	set_pte_at(mm, vaddr, ptep, ptev)
+#endif
+
 /* Unmap a local mapping which was obtained by kmap_high_get() */
 static inline bool kmap_high_unmap_local(unsigned long vaddr)
 {
@@ -515,7 +520,7 @@ void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
 	BUG_ON(!pte_none(*(kmap_pte - idx)));
 	pteval = pfn_pte(pfn, prot);
-	set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval);
+	arch_kmap_local_set_pte(&init_mm, vaddr, kmap_pte - idx, pteval);
 	arch_kmap_local_post_map(vaddr, pteval);
 	current->kmap_ctrl.pteval[kmap_local_idx()] = pteval;
 	preempt_enable();

mm/kasan/hw_tags.c

@@ -19,11 +19,10 @@
 
 #include "kasan.h"
 
-enum kasan_arg_mode {
-	KASAN_ARG_MODE_DEFAULT,
-	KASAN_ARG_MODE_OFF,
-	KASAN_ARG_MODE_PROD,
-	KASAN_ARG_MODE_FULL,
+enum kasan_arg {
+	KASAN_ARG_DEFAULT,
+	KASAN_ARG_OFF,
+	KASAN_ARG_ON,
 };
 
 enum kasan_arg_stacktrace {
@@ -38,7 +37,7 @@ enum kasan_arg_fault {
 	KASAN_ARG_FAULT_PANIC,
 };
 
-static enum kasan_arg_mode kasan_arg_mode __ro_after_init;
+static enum kasan_arg kasan_arg __ro_after_init;
 static enum kasan_arg_stacktrace kasan_arg_stacktrace __ro_after_init;
 static enum kasan_arg_fault kasan_arg_fault __ro_after_init;
 
@@ -52,26 +51,24 @@ DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
 /* Whether panic or disable tag checking on fault. */
 bool kasan_flag_panic __ro_after_init;
 
-/* kasan.mode=off/prod/full */
-static int __init early_kasan_mode(char *arg)
+/* kasan=off/on */
+static int __init early_kasan_flag(char *arg)
 {
 	if (!arg)
 		return -EINVAL;
 
 	if (!strcmp(arg, "off"))
-		kasan_arg_mode = KASAN_ARG_MODE_OFF;
-	else if (!strcmp(arg, "prod"))
-		kasan_arg_mode = KASAN_ARG_MODE_PROD;
-	else if (!strcmp(arg, "full"))
-		kasan_arg_mode = KASAN_ARG_MODE_FULL;
+		kasan_arg = KASAN_ARG_OFF;
+	else if (!strcmp(arg, "on"))
+		kasan_arg = KASAN_ARG_ON;
 	else
 		return -EINVAL;
 
 	return 0;
 }
-early_param("kasan.mode", early_kasan_mode);
+early_param("kasan", early_kasan_flag);
 
-/* kasan.stack=off/on */
+/* kasan.stacktrace=off/on */
 static int __init early_kasan_flag_stacktrace(char *arg)
 {
 	if (!arg)
@@ -113,8 +110,8 @@ void kasan_init_hw_tags_cpu(void)
 	 * as this function is only called for MTE-capable hardware.
 	 */
 
-	/* If KASAN is disabled, do nothing. */
-	if (kasan_arg_mode == KASAN_ARG_MODE_OFF)
+	/* If KASAN is disabled via command line, don't initialize it. */
+	if (kasan_arg == KASAN_ARG_OFF)
 		return;
 
 	hw_init_tags(KASAN_TAG_MAX);
@@ -124,43 +121,28 @@ void kasan_init_hw_tags_cpu(void)
 /* kasan_init_hw_tags() is called once on boot CPU. */
 void __init kasan_init_hw_tags(void)
 {
-	/* If hardware doesn't support MTE, do nothing. */
+	/* If hardware doesn't support MTE, don't initialize KASAN. */
 	if (!system_supports_mte())
 		return;
 
-	/* Choose KASAN mode if kasan boot parameter is not provided. */
-	if (kasan_arg_mode == KASAN_ARG_MODE_DEFAULT) {
-		if (IS_ENABLED(CONFIG_DEBUG_KERNEL))
-			kasan_arg_mode = KASAN_ARG_MODE_FULL;
-		else
-			kasan_arg_mode = KASAN_ARG_MODE_PROD;
-	}
-
-	/* Preset parameter values based on the mode. */
-	switch (kasan_arg_mode) {
-	case KASAN_ARG_MODE_DEFAULT:
-		/* Shouldn't happen as per the check above. */
-		WARN_ON(1);
+	/* If KASAN is disabled via command line, don't initialize it. */
+	if (kasan_arg == KASAN_ARG_OFF)
 		return;
-	case KASAN_ARG_MODE_OFF:
-		/* If KASAN is disabled, do nothing. */
-		return;
-	case KASAN_ARG_MODE_PROD:
-		static_branch_enable(&kasan_flag_enabled);
-		break;
-	case KASAN_ARG_MODE_FULL:
-		static_branch_enable(&kasan_flag_enabled);
-		static_branch_enable(&kasan_flag_stacktrace);
-		break;
-	}
 
-	/* Now, optionally override the presets. */
+	/* Enable KASAN. */
+	static_branch_enable(&kasan_flag_enabled);
 
 	switch (kasan_arg_stacktrace) {
 	case KASAN_ARG_STACKTRACE_DEFAULT:
+		/*
+		 * Default to enabling stack trace collection for
+		 * debug kernels.
+		 */
+		if (IS_ENABLED(CONFIG_DEBUG_KERNEL))
+			static_branch_enable(&kasan_flag_stacktrace);
 		break;
 	case KASAN_ARG_STACKTRACE_OFF:
-		static_branch_disable(&kasan_flag_stacktrace);
+		/* Do nothing, kasan_flag_stacktrace keeps its default value. */
 		break;
 	case KASAN_ARG_STACKTRACE_ON:
 		static_branch_enable(&kasan_flag_stacktrace);
@@ -169,11 +151,16 @@ void __init kasan_init_hw_tags(void)
 
 	switch (kasan_arg_fault) {
 	case KASAN_ARG_FAULT_DEFAULT:
+		/*
+		 * Default to no panic on report.
+		 * Do nothing, kasan_flag_panic keeps its default value.
+		 */
 		break;
 	case KASAN_ARG_FAULT_REPORT:
-		kasan_flag_panic = false;
+		/* Do nothing, kasan_flag_panic keeps its default value. */
 		break;
 	case KASAN_ARG_FAULT_PANIC:
+		/* Enable panic on report. */
 		kasan_flag_panic = true;
 		break;
 	}

mm/kasan/init.c

@@ -373,9 +373,10 @@ static void kasan_remove_pmd_table(pmd_t *pmd, unsigned long addr,
 
 		if (kasan_pte_table(*pmd)) {
 			if (IS_ALIGNED(addr, PMD_SIZE) &&
-			    IS_ALIGNED(next, PMD_SIZE))
+			    IS_ALIGNED(next, PMD_SIZE)) {
 				pmd_clear(pmd);
-			continue;
+				continue;
+			}
 		}
 		pte = pte_offset_kernel(pmd, addr);
 		kasan_remove_pte_table(pte, addr, next);
@@ -398,9 +399,10 @@ static void kasan_remove_pud_table(pud_t *pud, unsigned long addr,
 
 		if (kasan_pmd_table(*pud)) {
 			if (IS_ALIGNED(addr, PUD_SIZE) &&
-			    IS_ALIGNED(next, PUD_SIZE))
+			    IS_ALIGNED(next, PUD_SIZE)) {
 				pud_clear(pud);
-			continue;
+				continue;
+			}
 		}
 		pmd = pmd_offset(pud, addr);
 		pmd_base = pmd_offset(pud, 0);
@@ -424,9 +426,10 @@ static void kasan_remove_p4d_table(p4d_t *p4d, unsigned long addr,
 
 		if (kasan_pud_table(*p4d)) {
 			if (IS_ALIGNED(addr, P4D_SIZE) &&
-			    IS_ALIGNED(next, P4D_SIZE))
+			    IS_ALIGNED(next, P4D_SIZE)) {
 				p4d_clear(p4d);
-			continue;
+				continue;
+			}
 		}
 		pud = pud_offset(p4d, addr);
 		kasan_remove_pud_table(pud, addr, next);
@@ -457,9 +460,10 @@ void kasan_remove_zero_shadow(void *start, unsigned long size)
 
 		if (kasan_p4d_table(*pgd)) {
 			if (IS_ALIGNED(addr, PGDIR_SIZE) &&
-			    IS_ALIGNED(next, PGDIR_SIZE))
+			    IS_ALIGNED(next, PGDIR_SIZE)) {
 				pgd_clear(pgd);
-			continue;
+				continue;
+			}
 		}
 
 		p4d = p4d_offset(pgd, addr);
@@ -482,7 +486,6 @@ int kasan_add_zero_shadow(void *start, unsigned long size)
 
 	ret = kasan_populate_early_shadow(shadow_start, shadow_end);
 	if (ret)
-		kasan_remove_zero_shadow(shadow_start,
-					size >> KASAN_SHADOW_SCALE_SHIFT);
+		kasan_remove_zero_shadow(start, size);
 	return ret;
 }

mm/memcontrol.c

@@ -3115,9 +3115,7 @@ void __memcg_kmem_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages)
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		page_counter_uncharge(&memcg->kmem, nr_pages);
 
-	page_counter_uncharge(&memcg->memory, nr_pages);
-	if (do_memsw_account())
-		page_counter_uncharge(&memcg->memsw, nr_pages);
+	refill_stock(memcg, nr_pages);
 }
 
 /**

mm/memory-failure.c

@@ -1885,6 +1885,12 @@ static int soft_offline_free_page(struct page *page)
 	return rc;
 }
 
+static void put_ref_page(struct page *page)
+{
+	if (page)
+		put_page(page);
+}
+
 /**
  * soft_offline_page - Soft offline a page.
  * @pfn: pfn to soft-offline
@@ -1910,20 +1916,26 @@ static int soft_offline_free_page(struct page *page)
 int soft_offline_page(unsigned long pfn, int flags)
 {
 	int ret;
-	struct page *page;
 	bool try_again = true;
+	struct page *page, *ref_page = NULL;
+
+	WARN_ON_ONCE(!pfn_valid(pfn) && (flags & MF_COUNT_INCREASED));
 
 	if (!pfn_valid(pfn))
 		return -ENXIO;
+	if (flags & MF_COUNT_INCREASED)
+		ref_page = pfn_to_page(pfn);
+
 	/* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
 	page = pfn_to_online_page(pfn);
-	if (!page)
+	if (!page) {
+		put_ref_page(ref_page);
 		return -EIO;
+	}
 
 	if (PageHWPoison(page)) {
 		pr_info("%s: %#lx page already poisoned\n", __func__, pfn);
-		if (flags & MF_COUNT_INCREASED)
-			put_page(page);
+		put_ref_page(ref_page);
 		return 0;
 	}
 

mm/migrate.c

@@ -402,6 +402,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 	struct zone *oldzone, *newzone;
 	int dirty;
 	int expected_count = expected_page_refs(mapping, page) + extra_count;
+	int nr = thp_nr_pages(page);
 
 	if (!mapping) {
 		/* Anonymous page without mapping */
@@ -437,7 +438,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 	 */
 	newpage->index = page->index;
 	newpage->mapping = page->mapping;
-	page_ref_add(newpage, thp_nr_pages(page)); /* add cache reference */
+	page_ref_add(newpage, nr); /* add cache reference */
 	if (PageSwapBacked(page)) {
 		__SetPageSwapBacked(newpage);
 		if (PageSwapCache(page)) {
@@ -459,7 +460,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 	if (PageTransHuge(page)) {
 		int i;
 
-		for (i = 1; i < HPAGE_PMD_NR; i++) {
+		for (i = 1; i < nr; i++) {
 			xas_next(&xas);
 			xas_store(&xas, newpage);
 		}
@@ -470,7 +471,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 	 * to one less reference.
 	 * We know this isn't the last reference.
 	 */
-	page_ref_unfreeze(page, expected_count - thp_nr_pages(page));
+	page_ref_unfreeze(page, expected_count - nr);
 
 	xas_unlock(&xas);
 	/* Leave irq disabled to prevent preemption while updating stats */
@@ -493,17 +494,17 @@ int migrate_page_move_mapping(struct address_space *mapping,
 		old_lruvec = mem_cgroup_lruvec(memcg, oldzone->zone_pgdat);
 		new_lruvec = mem_cgroup_lruvec(memcg, newzone->zone_pgdat);
 
-		__dec_lruvec_state(old_lruvec, NR_FILE_PAGES);
-		__inc_lruvec_state(new_lruvec, NR_FILE_PAGES);
+		__mod_lruvec_state(old_lruvec, NR_FILE_PAGES, -nr);
+		__mod_lruvec_state(new_lruvec, NR_FILE_PAGES, nr);
 		if (PageSwapBacked(page) && !PageSwapCache(page)) {
-			__dec_lruvec_state(old_lruvec, NR_SHMEM);
-			__inc_lruvec_state(new_lruvec, NR_SHMEM);
+			__mod_lruvec_state(old_lruvec, NR_SHMEM, -nr);
+			__mod_lruvec_state(new_lruvec, NR_SHMEM, nr);
 		}
 		if (dirty && mapping_can_writeback(mapping)) {
-			__dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY);
-			__dec_zone_state(oldzone, NR_ZONE_WRITE_PENDING);
-			__inc_node_state(newzone->zone_pgdat, NR_FILE_DIRTY);
-			__inc_zone_state(newzone, NR_ZONE_WRITE_PENDING);
+			__mod_lruvec_state(old_lruvec, NR_FILE_DIRTY, -nr);
+			__mod_zone_page_state(oldzone, NR_ZONE_WRITE_PENDING, -nr);
+			__mod_lruvec_state(new_lruvec, NR_FILE_DIRTY, nr);
+			__mod_zone_page_state(newzone, NR_ZONE_WRITE_PENDING, nr);
 		}
 	}
 	local_irq_enable();

mm/page_alloc.c

@@ -1207,8 +1207,10 @@ static void kernel_init_free_pages(struct page *page, int numpages)
 	/* s390's use of memset() could override KASAN redzones. */
 	kasan_disable_current();
 	for (i = 0; i < numpages; i++) {
+		u8 tag = page_kasan_tag(page + i);
 		page_kasan_tag_reset(page + i);
 		clear_highpage(page + i);
+		page_kasan_tag_set(page + i, tag);
 	}
 	kasan_enable_current();
 }
@@ -7078,23 +7080,26 @@ void __init free_area_init_memoryless_node(int nid)
  * Initialize all valid struct pages in the range [spfn, epfn) and mark them
  * PageReserved(). Return the number of struct pages that were initialized.
  */
-static u64 __init init_unavailable_range(unsigned long spfn, unsigned long epfn)
+static u64 __init init_unavailable_range(unsigned long spfn, unsigned long epfn,
+					 int zone, int nid)
 {
-	unsigned long pfn;
+	unsigned long pfn, zone_spfn, zone_epfn;
 	u64 pgcnt = 0;
 
+	zone_spfn = arch_zone_lowest_possible_pfn[zone];
+	zone_epfn = arch_zone_highest_possible_pfn[zone];
+
+	spfn = clamp(spfn, zone_spfn, zone_epfn);
+	epfn = clamp(epfn, zone_spfn, zone_epfn);
+
 	for (pfn = spfn; pfn < epfn; pfn++) {
 		if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) {
 			pfn = ALIGN_DOWN(pfn, pageblock_nr_pages)
 				+ pageblock_nr_pages - 1;
 			continue;
 		}
-		/*
-		 * Use a fake node/zone (0) for now. Some of these pages
-		 * (in memblock.reserved but not in memblock.memory) will
-		 * get re-initialized via reserve_bootmem_region() later.
-		 */
-		__init_single_page(pfn_to_page(pfn), pfn, 0, 0);
+
+		__init_single_page(pfn_to_page(pfn), pfn, zone, nid);
 		__SetPageReserved(pfn_to_page(pfn));
 		pgcnt++;
 	}
@@ -7103,51 +7108,64 @@ static u64 __init init_unavailable_range(unsigned long spfn, unsigned long epfn)
 }
 
 /*
- * Only struct pages that are backed by physical memory are zeroed and
- * initialized by going through __init_single_page(). But, there are some
- * struct pages which are reserved in memblock allocator and their fields
- * may be accessed (for example page_to_pfn() on some configuration accesses
- * flags). We must explicitly initialize those struct pages.
+ * Only struct pages that correspond to ranges defined by memblock.memory
+ * are zeroed and initialized by going through __init_single_page() during
+ * memmap_init().
  *
- * This function also addresses a similar issue where struct pages are left
- * uninitialized because the physical address range is not covered by
- * memblock.memory or memblock.reserved. That could happen when memblock
- * layout is manually configured via memmap=, or when the highest physical
- * address (max_pfn) does not end on a section boundary.
+ * But, there could be struct pages that correspond to holes in
+ * memblock.memory. This can happen because of the following reasons:
+ * - phyiscal memory bank size is not necessarily the exact multiple of the
+ *   arbitrary section size
+ * - early reserved memory may not be listed in memblock.memory
+ * - memory layouts defined with memmap= kernel parameter may not align
+ *   nicely with memmap sections
+ *
+ * Explicitly initialize those struct pages so that:
+ * - PG_Reserved is set
+ * - zone link is set accorging to the architecture constrains
+ * - node is set to node id of the next populated region except for the
+ *   trailing hole where last node id is used
  */
-static void __init init_unavailable_mem(void)
+static void __init init_zone_unavailable_mem(int zone)
 {
-	phys_addr_t start, end;
-	u64 i, pgcnt;
-	phys_addr_t next = 0;
+	unsigned long start, end;
+	int i, nid;
+	u64 pgcnt;
+	unsigned long next = 0;
 
 	/*
-	 * Loop through unavailable ranges not covered by memblock.memory.
+	 * Loop through holes in memblock.memory and initialize struct
+	 * pages corresponding to these holes
 	 */
 	pgcnt = 0;
-	for_each_mem_range(i, &start, &end) {
+	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
 		if (next < start)
-			pgcnt += init_unavailable_range(PFN_DOWN(next),
-							PFN_UP(start));
+			pgcnt += init_unavailable_range(next, start, zone, nid);
 		next = end;
 	}
 
 	/*
-	 * Early sections always have a fully populated memmap for the whole
-	 * section - see pfn_valid(). If the last section has holes at the
-	 * end and that section is marked "online", the memmap will be
-	 * considered initialized. Make sure that memmap has a well defined
-	 * state.
+	 * Last section may surpass the actual end of memory (e.g. we can
+	 * have 1Gb section and 512Mb of RAM pouplated).
+	 * Make sure that memmap has a well defined state in this case.
 	 */
-	pgcnt += init_unavailable_range(PFN_DOWN(next),
-					round_up(max_pfn, PAGES_PER_SECTION));
+	end = round_up(max_pfn, PAGES_PER_SECTION);
+	pgcnt += init_unavailable_range(next, end, zone, nid);
 
 	/*
 	 * Struct pages that do not have backing memory. This could be because
 	 * firmware is using some of this memory, or for some other reasons.
 	 */
 	if (pgcnt)
-		pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt);
+		pr_info("Zone %s: zeroed struct page in unavailable ranges: %lld pages", zone_names[zone], pgcnt);
+}
+
+static void __init init_unavailable_mem(void)
+{
+	int zone;
+
+	for (zone = 0; zone < ZONE_MOVABLE; zone++)
+		init_zone_unavailable_mem(zone);
 }
 #else
 static inline void __init init_unavailable_mem(void)

mm/slub.c

@@ -2791,7 +2791,8 @@ static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
 						   void *obj)
 {
 	if (unlikely(slab_want_init_on_free(s)) && obj)
-		memset((void *)((char *)obj + s->offset), 0, sizeof(void *));
+		memset((void *)((char *)kasan_reset_tag(obj) + s->offset),
+			0, sizeof(void *));
 }
 
 /*
@@ -2883,7 +2884,7 @@ redo:
 		stat(s, ALLOC_FASTPATH);
 	}
 
-	maybe_wipe_obj_freeptr(s, kasan_reset_tag(object));
+	maybe_wipe_obj_freeptr(s, object);
 
 	if (unlikely(slab_want_init_on_alloc(gfpflags, s)) && object)
 		memset(kasan_reset_tag(object), 0, s->object_size);
@@ -3329,7 +3330,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 		int j;
 
 		for (j = 0; j < i; j++)
-			memset(p[j], 0, s->object_size);
+			memset(kasan_reset_tag(p[j]), 0, s->object_size);
 	}
 
 	/* memcg and kmem_cache debug support */