Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - large KASAN update to use arm's "software tag-based mode"

 - a few misc things

 - sh updates

 - ocfs2 updates

 - just about all of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (167 commits)
  kernel/fork.c: mark 'stack_vm_area' with __maybe_unused
  memcg, oom: notify on oom killer invocation from the charge path
  mm, swap: fix swapoff with KSM pages
  include/linux/gfp.h: fix typo
  mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
  hugetlbfs: Use i_mmap_rwsem to fix page fault/truncate race
  hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization
  memory_hotplug: add missing newlines to debugging output
  mm: remove __hugepage_set_anon_rmap()
  include/linux/vmstat.h: remove unused page state adjustment macro
  mm/page_alloc.c: allow error injection
  mm: migrate: drop unused argument of migrate_page_move_mapping()
  blkdev: avoid migration stalls for blkdev pages
  mm: migrate: provide buffer_migrate_page_norefs()
  mm: migrate: move migrate_page_lock_buffers()
  mm: migrate: lock buffers before migrate_page_move_mapping()
  mm: migration: factor out code to compute expected number of page references
  mm, page_alloc: enable pcpu_drain with zone capability
  kmemleak: add config to select auto scan
  mm/page_alloc.c: don't call kasan_free_pages() at deferred mem init
  ...

1 files changed, 499 insertions, 0 deletions

diff --git a/mm/kasan/init.c b/mm/kasan/init.c
new file mode 100644
index 000000000000..34afad56497b
--- /dev/null
+++ b/mm/kasan/init.c
@@ -0,0 +1,499 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file contains some kasan initialization code.
+ *
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/memblock.h>
+#include <linux/init.h>
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/pfn.h>
+#include <linux/slab.h>
+
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+
+#include "kasan.h"
+
+/*
+ * This page serves two purposes:
+ *   - It used as early shadow memory. The entire shadow region populated
+ *     with this page, before we will be able to setup normal shadow memory.
+ *   - Latter it reused it as zero shadow to cover large ranges of memory
+ *     that allowed to access, but not handled by kasan (vmalloc/vmemmap ...).
+ */
+unsigned char kasan_early_shadow_page[PAGE_SIZE] __page_aligned_bss;
+
+#if CONFIG_PGTABLE_LEVELS > 4
+p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss;
+static inline bool kasan_p4d_table(pgd_t pgd)
+{
+        return pgd_page(pgd) == virt_to_page(lm_alias(kasan_early_shadow_p4d));
+}
+#else
+static inline bool kasan_p4d_table(pgd_t pgd)
+{
+        return 0;
+}
+#endif
+#if CONFIG_PGTABLE_LEVELS > 3
+pud_t kasan_early_shadow_pud[PTRS_PER_PUD] __page_aligned_bss;
+static inline bool kasan_pud_table(p4d_t p4d)
+{
+        return p4d_page(p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud));
+}
+#else
+static inline bool kasan_pud_table(p4d_t p4d)
+{
+        return 0;
+}
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD] __page_aligned_bss;
+static inline bool kasan_pmd_table(pud_t pud)
+{
+        return pud_page(pud) == virt_to_page(lm_alias(kasan_early_shadow_pmd));
+}
+#else
+static inline bool kasan_pmd_table(pud_t pud)
+{
+        return 0;
+}
+#endif
+pte_t kasan_early_shadow_pte[PTRS_PER_PTE] __page_aligned_bss;
+
+static inline bool kasan_pte_table(pmd_t pmd)
+{
+        return pmd_page(pmd) == virt_to_page(lm_alias(kasan_early_shadow_pte));
+}
+
+static inline bool kasan_early_shadow_page_entry(pte_t pte)
+{
+        return pte_page(pte) == virt_to_page(lm_alias(kasan_early_shadow_page));
+}
+
+static __init void *early_alloc(size_t size, int node)
+{
+        return memblock_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS),
+                                        MEMBLOCK_ALLOC_ACCESSIBLE, node);
+}
+
+static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr,
+                                unsigned long end)
+{
+        pte_t *pte = pte_offset_kernel(pmd, addr);
+        pte_t zero_pte;
+
+        zero_pte = pfn_pte(PFN_DOWN(__pa_symbol(kasan_early_shadow_page)),
+                                PAGE_KERNEL);
+        zero_pte = pte_wrprotect(zero_pte);
+
+        while (addr + PAGE_SIZE <= end) {
+                set_pte_at(&init_mm, addr, pte, zero_pte);
+                addr += PAGE_SIZE;
+                pte = pte_offset_kernel(pmd, addr);
+        }
+}
+
+static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr,
+                                unsigned long end)
+{
+        pmd_t *pmd = pmd_offset(pud, addr);
+        unsigned long next;
+
+        do {
+                next = pmd_addr_end(addr, end);
+
+                if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) {
+                        pmd_populate_kernel(&init_mm, pmd,
+                                        lm_alias(kasan_early_shadow_pte));
+                        continue;
+                }
+
+                if (pmd_none(*pmd)) {
+                        pte_t *p;
+
+                        if (slab_is_available())
+                                p = pte_alloc_one_kernel(&init_mm, addr);
+                        else
+                                p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
+                        if (!p)
+                                return -ENOMEM;
+
+                        pmd_populate_kernel(&init_mm, pmd, p);
+                }
+                zero_pte_populate(pmd, addr, next);
+        } while (pmd++, addr = next, addr != end);
+
+        return 0;
+}
+
+static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
+                                unsigned long end)
+{
+        pud_t *pud = pud_offset(p4d, addr);
+        unsigned long next;
+
+        do {
+                next = pud_addr_end(addr, end);
+                if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) {
+                        pmd_t *pmd;
+
+                        pud_populate(&init_mm, pud,
+                                        lm_alias(kasan_early_shadow_pmd));
+                        pmd = pmd_offset(pud, addr);
+                        pmd_populate_kernel(&init_mm, pmd,
+                                        lm_alias(kasan_early_shadow_pte));
+                        continue;
+                }
+
+                if (pud_none(*pud)) {
+                        pmd_t *p;
+
+                        if (slab_is_available()) {
+                                p = pmd_alloc(&init_mm, pud, addr);
+                                if (!p)
+                                        return -ENOMEM;
+                        } else {
+                                pud_populate(&init_mm, pud,
+                                        early_alloc(PAGE_SIZE, NUMA_NO_NODE));
+                        }
+                }
+                zero_pmd_populate(pud, addr, next);
+        } while (pud++, addr = next, addr != end);
+
+        return 0;
+}
+
+static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
+                                unsigned long end)
+{
+        p4d_t *p4d = p4d_offset(pgd, addr);
+        unsigned long next;
+
+        do {
+                next = p4d_addr_end(addr, end);
+                if (IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) {
+                        pud_t *pud;
+                        pmd_t *pmd;
+
+                        p4d_populate(&init_mm, p4d,
+                                        lm_alias(kasan_early_shadow_pud));
+                        pud = pud_offset(p4d, addr);
+                        pud_populate(&init_mm, pud,
+                                        lm_alias(kasan_early_shadow_pmd));
+                        pmd = pmd_offset(pud, addr);
+                        pmd_populate_kernel(&init_mm, pmd,
+                                        lm_alias(kasan_early_shadow_pte));
+                        continue;
+                }
+
+                if (p4d_none(*p4d)) {
+                        pud_t *p;
+
+                        if (slab_is_available()) {
+                                p = pud_alloc(&init_mm, p4d, addr);
+                                if (!p)
+                                        return -ENOMEM;
+                        } else {
+                                p4d_populate(&init_mm, p4d,
+                                        early_alloc(PAGE_SIZE, NUMA_NO_NODE));
+                        }
+                }
+                zero_pud_populate(p4d, addr, next);
+        } while (p4d++, addr = next, addr != end);
+
+        return 0;
+}
+
+/**
+ * kasan_populate_early_shadow - populate shadow memory region with
+ *                               kasan_early_shadow_page
+ * @shadow_start - start of the memory range to populate
+ * @shadow_end   - end of the memory range to populate
+ */
+int __ref kasan_populate_early_shadow(const void *shadow_start,
+                                        const void *shadow_end)
+{
+        unsigned long addr = (unsigned long)shadow_start;
+        unsigned long end = (unsigned long)shadow_end;
+        pgd_t *pgd = pgd_offset_k(addr);
+        unsigned long next;
+
+        do {
+                next = pgd_addr_end(addr, end);
+
+                if (IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) {
+                        p4d_t *p4d;
+                        pud_t *pud;
+                        pmd_t *pmd;
+
+                        /*
+                         * kasan_early_shadow_pud should be populated with pmds
+                         * at this moment.
+                         * [pud,pmd]_populate*() below needed only for
+                         * 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));
+                        pud = pud_offset(p4d, addr);
+                        pud_populate(&init_mm, pud,
+                                        lm_alias(kasan_early_shadow_pmd));
+                        pmd = pmd_offset(pud, addr);
+                        pmd_populate_kernel(&init_mm, pmd,
+                                        lm_alias(kasan_early_shadow_pte));
+                        continue;
+                }
+
+                if (pgd_none(*pgd)) {
+                        p4d_t *p;
+
+                        if (slab_is_available()) {
+                                p = p4d_alloc(&init_mm, pgd, addr);
+                                if (!p)
+                                        return -ENOMEM;
+                        } else {
+                                pgd_populate(&init_mm, pgd,
+                                        early_alloc(PAGE_SIZE, NUMA_NO_NODE));
+                        }
+                }
+                zero_p4d_populate(pgd, addr, next);
+        } while (pgd++, addr = next, addr != end);
+
+        return 0;
+}
+
+static void kasan_free_pte(pte_t *pte_start, pmd_t *pmd)
+{
+        pte_t *pte;
+        int i;
+
+        for (i = 0; i < PTRS_PER_PTE; i++) {
+                pte = pte_start + i;
+                if (!pte_none(*pte))
+                        return;
+        }
+
+        pte_free_kernel(&init_mm, (pte_t *)page_to_virt(pmd_page(*pmd)));
+        pmd_clear(pmd);
+}
+
+static void kasan_free_pmd(pmd_t *pmd_start, pud_t *pud)
+{
+        pmd_t *pmd;
+        int i;
+
+        for (i = 0; i < PTRS_PER_PMD; i++) {
+                pmd = pmd_start + i;
+                if (!pmd_none(*pmd))
+                        return;
+        }
+
+        pmd_free(&init_mm, (pmd_t *)page_to_virt(pud_page(*pud)));
+        pud_clear(pud);
+}
+
+static void kasan_free_pud(pud_t *pud_start, p4d_t *p4d)
+{
+        pud_t *pud;
+        int i;
+
+        for (i = 0; i < PTRS_PER_PUD; i++) {
+                pud = pud_start + i;
+                if (!pud_none(*pud))
+                        return;
+        }
+
+        pud_free(&init_mm, (pud_t *)page_to_virt(p4d_page(*p4d)));
+        p4d_clear(p4d);
+}
+
+static void kasan_free_p4d(p4d_t *p4d_start, pgd_t *pgd)
+{
+        p4d_t *p4d;
+        int i;
+
+        for (i = 0; i < PTRS_PER_P4D; i++) {
+                p4d = p4d_start + i;
+                if (!p4d_none(*p4d))
+                        return;
+        }
+
+        p4d_free(&init_mm, (p4d_t *)page_to_virt(pgd_page(*pgd)));
+        pgd_clear(pgd);
+}
+
+static void kasan_remove_pte_table(pte_t *pte, unsigned long addr,
+                                unsigned long end)
+{
+        unsigned long next;
+
+        for (; addr < end; addr = next, pte++) {
+                next = (addr + PAGE_SIZE) & PAGE_MASK;
+                if (next > end)
+                        next = end;
+
+                if (!pte_present(*pte))
+                        continue;
+
+                if (WARN_ON(!kasan_early_shadow_page_entry(*pte)))
+                        continue;
+                pte_clear(&init_mm, addr, pte);
+        }
+}
+
+static void kasan_remove_pmd_table(pmd_t *pmd, unsigned long addr,
+                                unsigned long end)
+{
+        unsigned long next;
+
+        for (; addr < end; addr = next, pmd++) {
+                pte_t *pte;
+
+                next = pmd_addr_end(addr, end);
+
+                if (!pmd_present(*pmd))
+                        continue;
+
+                if (kasan_pte_table(*pmd)) {
+                        if (IS_ALIGNED(addr, PMD_SIZE) &&
+                            IS_ALIGNED(next, PMD_SIZE))
+                                pmd_clear(pmd);
+                        continue;
+                }
+                pte = pte_offset_kernel(pmd, addr);
+                kasan_remove_pte_table(pte, addr, next);
+                kasan_free_pte(pte_offset_kernel(pmd, 0), pmd);
+        }
+}
+
+static void kasan_remove_pud_table(pud_t *pud, unsigned long addr,
+                                unsigned long end)
+{
+        unsigned long next;
+
+        for (; addr < end; addr = next, pud++) {
+                pmd_t *pmd, *pmd_base;
+
+                next = pud_addr_end(addr, end);
+
+                if (!pud_present(*pud))
+                        continue;
+
+                if (kasan_pmd_table(*pud)) {
+                        if (IS_ALIGNED(addr, PUD_SIZE) &&
+                            IS_ALIGNED(next, PUD_SIZE))
+                                pud_clear(pud);
+                        continue;
+                }
+                pmd = pmd_offset(pud, addr);
+                pmd_base = pmd_offset(pud, 0);
+                kasan_remove_pmd_table(pmd, addr, next);
+                kasan_free_pmd(pmd_base, pud);
+        }
+}
+
+static void kasan_remove_p4d_table(p4d_t *p4d, unsigned long addr,
+                                unsigned long end)
+{
+        unsigned long next;
+
+        for (; addr < end; addr = next, p4d++) {
+                pud_t *pud;
+
+                next = p4d_addr_end(addr, end);
+
+                if (!p4d_present(*p4d))
+                        continue;
+
+                if (kasan_pud_table(*p4d)) {
+                        if (IS_ALIGNED(addr, P4D_SIZE) &&
+                            IS_ALIGNED(next, P4D_SIZE))
+                                p4d_clear(p4d);
+                        continue;
+                }
+                pud = pud_offset(p4d, addr);
+                kasan_remove_pud_table(pud, addr, next);
+                kasan_free_pud(pud_offset(p4d, 0), p4d);
+        }
+}
+
+void kasan_remove_zero_shadow(void *start, unsigned long size)
+{
+        unsigned long addr, end, next;
+        pgd_t *pgd;
+
+        addr = (unsigned long)kasan_mem_to_shadow(start);
+        end = addr + (size >> KASAN_SHADOW_SCALE_SHIFT);
+
+        if (WARN_ON((unsigned long)start %
+                        (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) ||
+            WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)))
+                return;
+
+        for (; addr < end; addr = next) {
+                p4d_t *p4d;
+
+                next = pgd_addr_end(addr, end);
+
+                pgd = pgd_offset_k(addr);
+                if (!pgd_present(*pgd))
+                        continue;
+
+                if (kasan_p4d_table(*pgd)) {
+                        if (IS_ALIGNED(addr, PGDIR_SIZE) &&
+                            IS_ALIGNED(next, PGDIR_SIZE))
+                                pgd_clear(pgd);
+                        continue;
+                }
+
+                p4d = p4d_offset(pgd, addr);
+                kasan_remove_p4d_table(p4d, addr, next);
+                kasan_free_p4d(p4d_offset(pgd, 0), pgd);
+        }
+}
+
+int kasan_add_zero_shadow(void *start, unsigned long size)
+{
+        int ret;
+        void *shadow_start, *shadow_end;
+
+        shadow_start = kasan_mem_to_shadow(start);
+        shadow_end = shadow_start + (size >> KASAN_SHADOW_SCALE_SHIFT);
+
+        if (WARN_ON((unsigned long)start %
+                        (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)) ||
+            WARN_ON(size % (KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE)))
+                return -EINVAL;
+
+        ret = kasan_populate_early_shadow(shadow_start, shadow_end);
+        if (ret)
+                kasan_remove_zero_shadow(shadow_start,
+                                        size >> KASAN_SHADOW_SCALE_SHIFT);
+        return ret;
+}