kasan: rename source files to reflect the new naming scheme
authorAndrey Konovalov <andreyknvl@google.com>
Fri, 28 Dec 2018 08:29:49 +0000 (00:29 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 28 Dec 2018 20:11:43 +0000 (12:11 -0800)
We now have two KASAN modes: generic KASAN and tag-based KASAN.  Rename
kasan.c to generic.c to reflect that.  Also rename kasan_init.c to init.c
as it contains initialization code for both KASAN modes.

Link: http://lkml.kernel.org/r/88c6fd2a883e459e6242030497230e5fb0d44d44.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/kasan/Makefile
mm/kasan/generic.c [new file with mode: 0644]
mm/kasan/init.c [new file with mode: 0644]
mm/kasan/kasan.c [deleted file]
mm/kasan/kasan_init.c [deleted file]

index a6df14bffb6b2bb25949b5045b72bd0737d604f2..d643530b24aae5c1501c74286c82274e43556560 100644 (file)
@@ -1,14 +1,14 @@
 # SPDX-License-Identifier: GPL-2.0
 KASAN_SANITIZE := n
 UBSAN_SANITIZE_common.o := n
-UBSAN_SANITIZE_kasan.o := n
+UBSAN_SANITIZE_generic.o := n
 KCOV_INSTRUMENT := n
 
-CFLAGS_REMOVE_kasan.o = -pg
+CFLAGS_REMOVE_generic.o = -pg
 # Function splitter causes unnecessary splits in __asan_load1/__asan_store1
 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
 
 CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 
-obj-y := common.o kasan.o report.o kasan_init.o quarantine.o
+obj-y := common.o generic.o report.o init.o quarantine.o
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
new file mode 100644 (file)
index 0000000..44ec228
--- /dev/null
@@ -0,0 +1,343 @@
+/*
+ * This file contains core KASAN code.
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ *
+ * Some code borrowed from https://github.com/xairy/kasan-prototype by
+ *        Andrey Konovalov <andreyknvl@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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/kmemleak.h>
+#include <linux/linkage.h>
+#include <linux/memblock.h>
+#include <linux/memory.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/slab.h>
+#include <linux/stacktrace.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+#include <linux/bug.h>
+
+#include "kasan.h"
+#include "../slab.h"
+
+/*
+ * All functions below always inlined so compiler could
+ * perform better optimizations in each of __asan_loadX/__assn_storeX
+ * depending on memory access size X.
+ */
+
+static __always_inline bool memory_is_poisoned_1(unsigned long addr)
+{
+       s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr);
+
+       if (unlikely(shadow_value)) {
+               s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
+               return unlikely(last_accessible_byte >= shadow_value);
+       }
+
+       return false;
+}
+
+static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr,
+                                               unsigned long size)
+{
+       u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr);
+
+       /*
+        * Access crosses 8(shadow size)-byte boundary. Such access maps
+        * into 2 shadow bytes, so we need to check them both.
+        */
+       if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1))
+               return *shadow_addr || memory_is_poisoned_1(addr + size - 1);
+
+       return memory_is_poisoned_1(addr + size - 1);
+}
+
+static __always_inline bool memory_is_poisoned_16(unsigned long addr)
+{
+       u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
+
+       /* Unaligned 16-bytes access maps into 3 shadow bytes. */
+       if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
+               return *shadow_addr || memory_is_poisoned_1(addr + 15);
+
+       return *shadow_addr;
+}
+
+static __always_inline unsigned long bytes_is_nonzero(const u8 *start,
+                                       size_t size)
+{
+       while (size) {
+               if (unlikely(*start))
+                       return (unsigned long)start;
+               start++;
+               size--;
+       }
+
+       return 0;
+}
+
+static __always_inline unsigned long memory_is_nonzero(const void *start,
+                                               const void *end)
+{
+       unsigned int words;
+       unsigned long ret;
+       unsigned int prefix = (unsigned long)start % 8;
+
+       if (end - start <= 16)
+               return bytes_is_nonzero(start, end - start);
+
+       if (prefix) {
+               prefix = 8 - prefix;
+               ret = bytes_is_nonzero(start, prefix);
+               if (unlikely(ret))
+                       return ret;
+               start += prefix;
+       }
+
+       words = (end - start) / 8;
+       while (words) {
+               if (unlikely(*(u64 *)start))
+                       return bytes_is_nonzero(start, 8);
+               start += 8;
+               words--;
+       }
+
+       return bytes_is_nonzero(start, (end - start) % 8);
+}
+
+static __always_inline bool memory_is_poisoned_n(unsigned long addr,
+                                               size_t size)
+{
+       unsigned long ret;
+
+       ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr),
+                       kasan_mem_to_shadow((void *)addr + size - 1) + 1);
+
+       if (unlikely(ret)) {
+               unsigned long last_byte = addr + size - 1;
+               s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte);
+
+               if (unlikely(ret != (unsigned long)last_shadow ||
+                       ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
+                       return true;
+       }
+       return false;
+}
+
+static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
+{
+       if (__builtin_constant_p(size)) {
+               switch (size) {
+               case 1:
+                       return memory_is_poisoned_1(addr);
+               case 2:
+               case 4:
+               case 8:
+                       return memory_is_poisoned_2_4_8(addr, size);
+               case 16:
+                       return memory_is_poisoned_16(addr);
+               default:
+                       BUILD_BUG();
+               }
+       }
+
+       return memory_is_poisoned_n(addr, size);
+}
+
+static __always_inline void check_memory_region_inline(unsigned long addr,
+                                               size_t size, bool write,
+                                               unsigned long ret_ip)
+{
+       if (unlikely(size == 0))
+               return;
+
+       if (unlikely((void *)addr <
+               kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
+               kasan_report(addr, size, write, ret_ip);
+               return;
+       }
+
+       if (likely(!memory_is_poisoned(addr, size)))
+               return;
+
+       kasan_report(addr, size, write, ret_ip);
+}
+
+void check_memory_region(unsigned long addr, size_t size, bool write,
+                               unsigned long ret_ip)
+{
+       check_memory_region_inline(addr, size, write, ret_ip);
+}
+
+void kasan_cache_shrink(struct kmem_cache *cache)
+{
+       quarantine_remove_cache(cache);
+}
+
+void kasan_cache_shutdown(struct kmem_cache *cache)
+{
+       if (!__kmem_cache_empty(cache))
+               quarantine_remove_cache(cache);
+}
+
+static void register_global(struct kasan_global *global)
+{
+       size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);
+
+       kasan_unpoison_shadow(global->beg, global->size);
+
+       kasan_poison_shadow(global->beg + aligned_size,
+               global->size_with_redzone - aligned_size,
+               KASAN_GLOBAL_REDZONE);
+}
+
+void __asan_register_globals(struct kasan_global *globals, size_t size)
+{
+       int i;
+
+       for (i = 0; i < size; i++)
+               register_global(&globals[i]);
+}
+EXPORT_SYMBOL(__asan_register_globals);
+
+void __asan_unregister_globals(struct kasan_global *globals, size_t size)
+{
+}
+EXPORT_SYMBOL(__asan_unregister_globals);
+
+#define DEFINE_ASAN_LOAD_STORE(size)                                   \
+       void __asan_load##size(unsigned long addr)                      \
+       {                                                               \
+               check_memory_region_inline(addr, size, false, _RET_IP_);\
+       }                                                               \
+       EXPORT_SYMBOL(__asan_load##size);                               \
+       __alias(__asan_load##size)                                      \
+       void __asan_load##size##_noabort(unsigned long);                \
+       EXPORT_SYMBOL(__asan_load##size##_noabort);                     \
+       void __asan_store##size(unsigned long addr)                     \
+       {                                                               \
+               check_memory_region_inline(addr, size, true, _RET_IP_); \
+       }                                                               \
+       EXPORT_SYMBOL(__asan_store##size);                              \
+       __alias(__asan_store##size)                                     \
+       void __asan_store##size##_noabort(unsigned long);               \
+       EXPORT_SYMBOL(__asan_store##size##_noabort)
+
+DEFINE_ASAN_LOAD_STORE(1);
+DEFINE_ASAN_LOAD_STORE(2);
+DEFINE_ASAN_LOAD_STORE(4);
+DEFINE_ASAN_LOAD_STORE(8);
+DEFINE_ASAN_LOAD_STORE(16);
+
+void __asan_loadN(unsigned long addr, size_t size)
+{
+       check_memory_region(addr, size, false, _RET_IP_);
+}
+EXPORT_SYMBOL(__asan_loadN);
+
+__alias(__asan_loadN)
+void __asan_loadN_noabort(unsigned long, size_t);
+EXPORT_SYMBOL(__asan_loadN_noabort);
+
+void __asan_storeN(unsigned long addr, size_t size)
+{
+       check_memory_region(addr, size, true, _RET_IP_);
+}
+EXPORT_SYMBOL(__asan_storeN);
+
+__alias(__asan_storeN)
+void __asan_storeN_noabort(unsigned long, size_t);
+EXPORT_SYMBOL(__asan_storeN_noabort);
+
+/* to shut up compiler complaints */
+void __asan_handle_no_return(void) {}
+EXPORT_SYMBOL(__asan_handle_no_return);
+
+/* Emitted by compiler to poison large objects when they go out of scope. */
+void __asan_poison_stack_memory(const void *addr, size_t size)
+{
+       /*
+        * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded
+        * by redzones, so we simply round up size to simplify logic.
+        */
+       kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE),
+                           KASAN_USE_AFTER_SCOPE);
+}
+EXPORT_SYMBOL(__asan_poison_stack_memory);
+
+/* Emitted by compiler to unpoison large objects when they go into scope. */
+void __asan_unpoison_stack_memory(const void *addr, size_t size)
+{
+       kasan_unpoison_shadow(addr, size);
+}
+EXPORT_SYMBOL(__asan_unpoison_stack_memory);
+
+/* Emitted by compiler to poison alloca()ed objects. */
+void __asan_alloca_poison(unsigned long addr, size_t size)
+{
+       size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
+       size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) -
+                       rounded_up_size;
+       size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE);
+
+       const void *left_redzone = (const void *)(addr -
+                       KASAN_ALLOCA_REDZONE_SIZE);
+       const void *right_redzone = (const void *)(addr + rounded_up_size);
+
+       WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
+
+       kasan_unpoison_shadow((const void *)(addr + rounded_down_size),
+                             size - rounded_down_size);
+       kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
+                       KASAN_ALLOCA_LEFT);
+       kasan_poison_shadow(right_redzone,
+                       padding_size + KASAN_ALLOCA_REDZONE_SIZE,
+                       KASAN_ALLOCA_RIGHT);
+}
+EXPORT_SYMBOL(__asan_alloca_poison);
+
+/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */
+void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
+{
+       if (unlikely(!stack_top || stack_top > stack_bottom))
+               return;
+
+       kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
+}
+EXPORT_SYMBOL(__asan_allocas_unpoison);
+
+/* Emitted by the compiler to [un]poison local variables. */
+#define DEFINE_ASAN_SET_SHADOW(byte) \
+       void __asan_set_shadow_##byte(const void *addr, size_t size)    \
+       {                                                               \
+               __memset((void *)addr, 0x##byte, size);                 \
+       }                                                               \
+       EXPORT_SYMBOL(__asan_set_shadow_##byte)
+
+DEFINE_ASAN_SET_SHADOW(00);
+DEFINE_ASAN_SET_SHADOW(f1);
+DEFINE_ASAN_SET_SHADOW(f2);
+DEFINE_ASAN_SET_SHADOW(f3);
+DEFINE_ASAN_SET_SHADOW(f5);
+DEFINE_ASAN_SET_SHADOW(f8);
diff --git a/mm/kasan/init.c b/mm/kasan/init.c
new file mode 100644 (file)
index 0000000..c7550eb
--- /dev/null
@@ -0,0 +1,488 @@
+/*
+ * 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_zero_page[PAGE_SIZE] __page_aligned_bss;
+
+#if CONFIG_PGTABLE_LEVELS > 4
+p4d_t kasan_zero_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_zero_p4d));
+}
+#else
+static inline bool kasan_p4d_table(pgd_t pgd)
+{
+       return 0;
+}
+#endif
+#if CONFIG_PGTABLE_LEVELS > 3
+pud_t kasan_zero_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_zero_pud));
+}
+#else
+static inline bool kasan_pud_table(p4d_t p4d)
+{
+       return 0;
+}
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+pmd_t kasan_zero_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_zero_pmd));
+}
+#else
+static inline bool kasan_pmd_table(pud_t pud)
+{
+       return 0;
+}
+#endif
+pte_t kasan_zero_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_zero_pte));
+}
+
+static inline bool kasan_zero_page_entry(pte_t pte)
+{
+       return pte_page(pte) == virt_to_page(lm_alias(kasan_zero_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_zero_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_zero_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_zero_pmd));
+                       pmd = pmd_offset(pud, addr);
+                       pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_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_zero_pud));
+                       pud = pud_offset(p4d, addr);
+                       pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
+                       pmd = pmd_offset(pud, addr);
+                       pmd_populate_kernel(&init_mm, pmd,
+                                               lm_alias(kasan_zero_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_zero_shadow - populate shadow memory region with
+ *                               kasan_zero_page
+ * @shadow_start - start of the memory range to populate
+ * @shadow_end   - end of the memory range to populate
+ */
+int __ref kasan_populate_zero_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_zero_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_zero_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_zero_p4d));
+#endif
+                       p4d = p4d_offset(pgd, addr);
+                       p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud));
+                       pud = pud_offset(p4d, addr);
+                       pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
+                       pmd = pmd_offset(pud, addr);
+                       pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_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_zero_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_zero_shadow(shadow_start, shadow_end);
+       if (ret)
+               kasan_remove_zero_shadow(shadow_start,
+                                       size >> KASAN_SHADOW_SCALE_SHIFT);
+       return ret;
+}
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
deleted file mode 100644 (file)
index 44ec228..0000000
+++ /dev/null
@@ -1,343 +0,0 @@
-/*
- * This file contains core KASAN code.
- *
- * Copyright (c) 2014 Samsung Electronics Co., Ltd.
- * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
- *
- * Some code borrowed from https://github.com/xairy/kasan-prototype by
- *        Andrey Konovalov <andreyknvl@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.
- *
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#define DISABLE_BRANCH_PROFILING
-
-#include <linux/export.h>
-#include <linux/interrupt.h>
-#include <linux/init.h>
-#include <linux/kasan.h>
-#include <linux/kernel.h>
-#include <linux/kmemleak.h>
-#include <linux/linkage.h>
-#include <linux/memblock.h>
-#include <linux/memory.h>
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/printk.h>
-#include <linux/sched.h>
-#include <linux/sched/task_stack.h>
-#include <linux/slab.h>
-#include <linux/stacktrace.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/vmalloc.h>
-#include <linux/bug.h>
-
-#include "kasan.h"
-#include "../slab.h"
-
-/*
- * All functions below always inlined so compiler could
- * perform better optimizations in each of __asan_loadX/__assn_storeX
- * depending on memory access size X.
- */
-
-static __always_inline bool memory_is_poisoned_1(unsigned long addr)
-{
-       s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr);
-
-       if (unlikely(shadow_value)) {
-               s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
-               return unlikely(last_accessible_byte >= shadow_value);
-       }
-
-       return false;
-}
-
-static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr,
-                                               unsigned long size)
-{
-       u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr);
-
-       /*
-        * Access crosses 8(shadow size)-byte boundary. Such access maps
-        * into 2 shadow bytes, so we need to check them both.
-        */
-       if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1))
-               return *shadow_addr || memory_is_poisoned_1(addr + size - 1);
-
-       return memory_is_poisoned_1(addr + size - 1);
-}
-
-static __always_inline bool memory_is_poisoned_16(unsigned long addr)
-{
-       u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
-
-       /* Unaligned 16-bytes access maps into 3 shadow bytes. */
-       if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
-               return *shadow_addr || memory_is_poisoned_1(addr + 15);
-
-       return *shadow_addr;
-}
-
-static __always_inline unsigned long bytes_is_nonzero(const u8 *start,
-                                       size_t size)
-{
-       while (size) {
-               if (unlikely(*start))
-                       return (unsigned long)start;
-               start++;
-               size--;
-       }
-
-       return 0;
-}
-
-static __always_inline unsigned long memory_is_nonzero(const void *start,
-                                               const void *end)
-{
-       unsigned int words;
-       unsigned long ret;
-       unsigned int prefix = (unsigned long)start % 8;
-
-       if (end - start <= 16)
-               return bytes_is_nonzero(start, end - start);
-
-       if (prefix) {
-               prefix = 8 - prefix;
-               ret = bytes_is_nonzero(start, prefix);
-               if (unlikely(ret))
-                       return ret;
-               start += prefix;
-       }
-
-       words = (end - start) / 8;
-       while (words) {
-               if (unlikely(*(u64 *)start))
-                       return bytes_is_nonzero(start, 8);
-               start += 8;
-               words--;
-       }
-
-       return bytes_is_nonzero(start, (end - start) % 8);
-}
-
-static __always_inline bool memory_is_poisoned_n(unsigned long addr,
-                                               size_t size)
-{
-       unsigned long ret;
-
-       ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr),
-                       kasan_mem_to_shadow((void *)addr + size - 1) + 1);
-
-       if (unlikely(ret)) {
-               unsigned long last_byte = addr + size - 1;
-               s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte);
-
-               if (unlikely(ret != (unsigned long)last_shadow ||
-                       ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
-                       return true;
-       }
-       return false;
-}
-
-static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
-{
-       if (__builtin_constant_p(size)) {
-               switch (size) {
-               case 1:
-                       return memory_is_poisoned_1(addr);
-               case 2:
-               case 4:
-               case 8:
-                       return memory_is_poisoned_2_4_8(addr, size);
-               case 16:
-                       return memory_is_poisoned_16(addr);
-               default:
-                       BUILD_BUG();
-               }
-       }
-
-       return memory_is_poisoned_n(addr, size);
-}
-
-static __always_inline void check_memory_region_inline(unsigned long addr,
-                                               size_t size, bool write,
-                                               unsigned long ret_ip)
-{
-       if (unlikely(size == 0))
-               return;
-
-       if (unlikely((void *)addr <
-               kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
-               kasan_report(addr, size, write, ret_ip);
-               return;
-       }
-
-       if (likely(!memory_is_poisoned(addr, size)))
-               return;
-
-       kasan_report(addr, size, write, ret_ip);
-}
-
-void check_memory_region(unsigned long addr, size_t size, bool write,
-                               unsigned long ret_ip)
-{
-       check_memory_region_inline(addr, size, write, ret_ip);
-}
-
-void kasan_cache_shrink(struct kmem_cache *cache)
-{
-       quarantine_remove_cache(cache);
-}
-
-void kasan_cache_shutdown(struct kmem_cache *cache)
-{
-       if (!__kmem_cache_empty(cache))
-               quarantine_remove_cache(cache);
-}
-
-static void register_global(struct kasan_global *global)
-{
-       size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);
-
-       kasan_unpoison_shadow(global->beg, global->size);
-
-       kasan_poison_shadow(global->beg + aligned_size,
-               global->size_with_redzone - aligned_size,
-               KASAN_GLOBAL_REDZONE);
-}
-
-void __asan_register_globals(struct kasan_global *globals, size_t size)
-{
-       int i;
-
-       for (i = 0; i < size; i++)
-               register_global(&globals[i]);
-}
-EXPORT_SYMBOL(__asan_register_globals);
-
-void __asan_unregister_globals(struct kasan_global *globals, size_t size)
-{
-}
-EXPORT_SYMBOL(__asan_unregister_globals);
-
-#define DEFINE_ASAN_LOAD_STORE(size)                                   \
-       void __asan_load##size(unsigned long addr)                      \
-       {                                                               \
-               check_memory_region_inline(addr, size, false, _RET_IP_);\
-       }                                                               \
-       EXPORT_SYMBOL(__asan_load##size);                               \
-       __alias(__asan_load##size)                                      \
-       void __asan_load##size##_noabort(unsigned long);                \
-       EXPORT_SYMBOL(__asan_load##size##_noabort);                     \
-       void __asan_store##size(unsigned long addr)                     \
-       {                                                               \
-               check_memory_region_inline(addr, size, true, _RET_IP_); \
-       }                                                               \
-       EXPORT_SYMBOL(__asan_store##size);                              \
-       __alias(__asan_store##size)                                     \
-       void __asan_store##size##_noabort(unsigned long);               \
-       EXPORT_SYMBOL(__asan_store##size##_noabort)
-
-DEFINE_ASAN_LOAD_STORE(1);
-DEFINE_ASAN_LOAD_STORE(2);
-DEFINE_ASAN_LOAD_STORE(4);
-DEFINE_ASAN_LOAD_STORE(8);
-DEFINE_ASAN_LOAD_STORE(16);
-
-void __asan_loadN(unsigned long addr, size_t size)
-{
-       check_memory_region(addr, size, false, _RET_IP_);
-}
-EXPORT_SYMBOL(__asan_loadN);
-
-__alias(__asan_loadN)
-void __asan_loadN_noabort(unsigned long, size_t);
-EXPORT_SYMBOL(__asan_loadN_noabort);
-
-void __asan_storeN(unsigned long addr, size_t size)
-{
-       check_memory_region(addr, size, true, _RET_IP_);
-}
-EXPORT_SYMBOL(__asan_storeN);
-
-__alias(__asan_storeN)
-void __asan_storeN_noabort(unsigned long, size_t);
-EXPORT_SYMBOL(__asan_storeN_noabort);
-
-/* to shut up compiler complaints */
-void __asan_handle_no_return(void) {}
-EXPORT_SYMBOL(__asan_handle_no_return);
-
-/* Emitted by compiler to poison large objects when they go out of scope. */
-void __asan_poison_stack_memory(const void *addr, size_t size)
-{
-       /*
-        * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded
-        * by redzones, so we simply round up size to simplify logic.
-        */
-       kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE),
-                           KASAN_USE_AFTER_SCOPE);
-}
-EXPORT_SYMBOL(__asan_poison_stack_memory);
-
-/* Emitted by compiler to unpoison large objects when they go into scope. */
-void __asan_unpoison_stack_memory(const void *addr, size_t size)
-{
-       kasan_unpoison_shadow(addr, size);
-}
-EXPORT_SYMBOL(__asan_unpoison_stack_memory);
-
-/* Emitted by compiler to poison alloca()ed objects. */
-void __asan_alloca_poison(unsigned long addr, size_t size)
-{
-       size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
-       size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) -
-                       rounded_up_size;
-       size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE);
-
-       const void *left_redzone = (const void *)(addr -
-                       KASAN_ALLOCA_REDZONE_SIZE);
-       const void *right_redzone = (const void *)(addr + rounded_up_size);
-
-       WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
-
-       kasan_unpoison_shadow((const void *)(addr + rounded_down_size),
-                             size - rounded_down_size);
-       kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
-                       KASAN_ALLOCA_LEFT);
-       kasan_poison_shadow(right_redzone,
-                       padding_size + KASAN_ALLOCA_REDZONE_SIZE,
-                       KASAN_ALLOCA_RIGHT);
-}
-EXPORT_SYMBOL(__asan_alloca_poison);
-
-/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */
-void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
-{
-       if (unlikely(!stack_top || stack_top > stack_bottom))
-               return;
-
-       kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
-}
-EXPORT_SYMBOL(__asan_allocas_unpoison);
-
-/* Emitted by the compiler to [un]poison local variables. */
-#define DEFINE_ASAN_SET_SHADOW(byte) \
-       void __asan_set_shadow_##byte(const void *addr, size_t size)    \
-       {                                                               \
-               __memset((void *)addr, 0x##byte, size);                 \
-       }                                                               \
-       EXPORT_SYMBOL(__asan_set_shadow_##byte)
-
-DEFINE_ASAN_SET_SHADOW(00);
-DEFINE_ASAN_SET_SHADOW(f1);
-DEFINE_ASAN_SET_SHADOW(f2);
-DEFINE_ASAN_SET_SHADOW(f3);
-DEFINE_ASAN_SET_SHADOW(f5);
-DEFINE_ASAN_SET_SHADOW(f8);
diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c
deleted file mode 100644 (file)
index c7550eb..0000000
+++ /dev/null
@@ -1,488 +0,0 @@
-/*
- * 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_zero_page[PAGE_SIZE] __page_aligned_bss;
-
-#if CONFIG_PGTABLE_LEVELS > 4
-p4d_t kasan_zero_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_zero_p4d));
-}
-#else
-static inline bool kasan_p4d_table(pgd_t pgd)
-{
-       return 0;
-}
-#endif
-#if CONFIG_PGTABLE_LEVELS > 3
-pud_t kasan_zero_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_zero_pud));
-}
-#else
-static inline bool kasan_pud_table(p4d_t p4d)
-{
-       return 0;
-}
-#endif
-#if CONFIG_PGTABLE_LEVELS > 2
-pmd_t kasan_zero_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_zero_pmd));
-}
-#else
-static inline bool kasan_pmd_table(pud_t pud)
-{
-       return 0;
-}
-#endif
-pte_t kasan_zero_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_zero_pte));
-}
-
-static inline bool kasan_zero_page_entry(pte_t pte)
-{
-       return pte_page(pte) == virt_to_page(lm_alias(kasan_zero_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_zero_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_zero_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_zero_pmd));
-                       pmd = pmd_offset(pud, addr);
-                       pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_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_zero_pud));
-                       pud = pud_offset(p4d, addr);
-                       pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
-                       pmd = pmd_offset(pud, addr);
-                       pmd_populate_kernel(&init_mm, pmd,
-                                               lm_alias(kasan_zero_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_zero_shadow - populate shadow memory region with
- *                               kasan_zero_page
- * @shadow_start - start of the memory range to populate
- * @shadow_end   - end of the memory range to populate
- */
-int __ref kasan_populate_zero_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_zero_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_zero_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_zero_p4d));
-#endif
-                       p4d = p4d_offset(pgd, addr);
-                       p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud));
-                       pud = pud_offset(p4d, addr);
-                       pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd));
-                       pmd = pmd_offset(pud, addr);
-                       pmd_populate_kernel(&init_mm, pmd, lm_alias(kasan_zero_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_zero_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_zero_shadow(shadow_start, shadow_end);
-       if (ret)
-               kasan_remove_zero_shadow(shadow_start,
-                                       size >> KASAN_SHADOW_SCALE_SHIFT);
-       return ret;
-}