23 files changed, 364 insertions, 20 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0fdc120de8d3..e7fd3bda2055 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -83,6 +83,7 @@ config X86
 	select HAVE_CMPXCHG_LOCAL
 	select HAVE_CMPXCHG_DOUBLE
 	select HAVE_ARCH_KMEMCHECK
+	select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
 	select HAVE_USER_RETURN_NOTIFIER
 	select ARCH_BINFMT_ELF_RANDOMIZE_PIE
 	select HAVE_ARCH_JUMP_LABEL
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index 3db07f30636f..ff6dc20d4b1b 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -9,6 +9,8 @@
 # Changed by many, many contributors over the years.
 #
 
+KASAN_SANITIZE := n
+
 # If you want to preset the SVGA mode, uncomment the next line and
 # set SVGA_MODE to whatever number you want.
 # Set it to -DSVGA_MODE=NORMAL_VGA if you just want the EGA/VGA mode.
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 30c0acf4ea6c..2959cca0b90c 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -4,6 +4,8 @@
 # create a compressed vmlinux image from the original vmlinux
 #
 
+KASAN_SANITIZE := n
+
 targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
 	vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
 
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index acdf06bc418b..2da9cef8ee43 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -13,8 +13,7 @@
 #include <asm/setup.h>
 #include <asm/desc.h>
 
-#undef memcpy			/* Use memcpy from misc.c */
-
+#include "../string.h"
 #include "eboot.h"
 
 static efi_system_table_t *sys_table;
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 24e3e569a13c..04477d68403f 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -7,6 +7,7 @@
  * we just keep it from happening
  */
 #undef CONFIG_PARAVIRT
+#undef CONFIG_KASAN
 #ifdef CONFIG_X86_32
 #define _ASM_X86_DESC_H 1
 #endif
diff --git a/arch/x86/include/asm/kasan.h b/arch/x86/include/asm/kasan.h
new file mode 100644
index 000000000000..491e4fd7754e
--- /dev/null
+++ b/arch/x86/include/asm/kasan.h
@@ -0,0 +1,34 @@
+#ifndef _ASM_X86_KASAN_H
+#define _ASM_X86_KASAN_H
+
+#include <linux/const.h>
+#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
+
+/*
+ * Compiler uses shadow offset assuming that addresses start
+ * from 0. Kernel addresses don't start from 0, so shadow
+ * for kernel really starts from compiler's shadow offset +
+ * 'kernel address space start' >> KASAN_SHADOW_SCALE_SHIFT
+ */
+#define KASAN_SHADOW_START      (KASAN_SHADOW_OFFSET + \
+					(0xffff800000000000ULL >> 3))
+/* 47 bits for kernel address -> (47 - 3) bits for shadow */
+#define KASAN_SHADOW_END        (KASAN_SHADOW_START + (1ULL << (47 - 3)))
+
+#ifndef __ASSEMBLY__
+
+extern pte_t kasan_zero_pte[];
+extern pte_t kasan_zero_pmd[];
+extern pte_t kasan_zero_pud[];
+
+#ifdef CONFIG_KASAN
+void __init kasan_map_early_shadow(pgd_t *pgd);
+void __init kasan_init(void);
+#else
+static inline void kasan_map_early_shadow(pgd_t *pgd) { }
+static inline void kasan_init(void) { }
+#endif
+
+#endif
+
+#endif
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 75450b2c7be4..4edd53b79a81 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -1,17 +1,23 @@
 #ifndef _ASM_X86_PAGE_64_DEFS_H
 #define _ASM_X86_PAGE_64_DEFS_H
 
-#define THREAD_SIZE_ORDER	2
+#ifdef CONFIG_KASAN
+#define KASAN_STACK_ORDER 1
+#else
+#define KASAN_STACK_ORDER 0
+#endif
+
+#define THREAD_SIZE_ORDER	(2 + KASAN_STACK_ORDER)
 #define THREAD_SIZE  (PAGE_SIZE << THREAD_SIZE_ORDER)
 #define CURRENT_MASK (~(THREAD_SIZE - 1))
 
-#define EXCEPTION_STACK_ORDER 0
+#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER)
 #define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
 
 #define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1)
 #define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER)
 
-#define IRQ_STACK_ORDER 2
+#define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER)
 #define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER)
 
 #define DOUBLEFAULT_STACK 1
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 19e2c468fc2c..e4661196994e 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -27,11 +27,12 @@ static __always_inline void *__inline_memcpy(void *to, const void *from, size_t
    function. */
 
 #define __HAVE_ARCH_MEMCPY 1
+extern void *__memcpy(void *to, const void *from, size_t len);
+
 #ifndef CONFIG_KMEMCHECK
 #if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
 extern void *memcpy(void *to, const void *from, size_t len);
 #else
-extern void *__memcpy(void *to, const void *from, size_t len);
 #define memcpy(dst, src, len)					\
 ({								\
 	size_t __len = (len);					\
@@ -53,9 +54,11 @@ extern void *__memcpy(void *to, const void *from, size_t len);
 
 #define __HAVE_ARCH_MEMSET
 void *memset(void *s, int c, size_t n);
+void *__memset(void *s, int c, size_t n);
 
 #define __HAVE_ARCH_MEMMOVE
 void *memmove(void *dest, const void *src, size_t count);
+void *__memmove(void *dest, const void *src, size_t count);
 
 int memcmp(const void *cs, const void *ct, size_t count);
 size_t strlen(const char *s);
@@ -63,6 +66,19 @@ char *strcpy(char *dest, const char *src);
 char *strcat(char *dest, const char *src);
 int strcmp(const char *cs, const char *ct);
 
+#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
+
+/*
+ * For files that not instrumented (e.g. mm/slub.c) we
+ * should use not instrumented version of mem* functions.
+ */
+
+#undef memcpy
+#define memcpy(dst, src, len) __memcpy(dst, src, len)
+#define memmove(dst, src, len) __memmove(dst, src, len)
+#define memset(s, c, n) __memset(s, c, n)
+#endif
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_X86_STRING_64_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 8f1e77440b2b..2e7f86e8a4a6 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -16,6 +16,10 @@ CFLAGS_REMOVE_ftrace.o = -pg
 CFLAGS_REMOVE_early_printk.o = -pg
 endif
 
+KASAN_SANITIZE_head$(BITS).o := n
+KASAN_SANITIZE_dumpstack.o := n
+KASAN_SANITIZE_dumpstack_$(BITS).o := n
+
 CFLAGS_irq.o := -I$(src)/../include/asm/trace
 
 obj-y			:= process_$(BITS).o signal.o entry_$(BITS).o
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index b74ebc7c4402..cf3df1d8d039 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -265,7 +265,10 @@ int __die(const char *str, struct pt_regs *regs, long err)
 	printk("SMP ");
 #endif
 #ifdef CONFIG_DEBUG_PAGEALLOC
-	printk("DEBUG_PAGEALLOC");
+	printk("DEBUG_PAGEALLOC ");
+#endif
+#ifdef CONFIG_KASAN
+	printk("KASAN");
 #endif
 	printk("\n");
 	if (notify_die(DIE_OOPS, str, regs, err,
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 957fdb5eb2e3..b111ab5c4509 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -27,6 +27,7 @@
 #include <asm/bios_ebda.h>
 #include <asm/bootparam_utils.h>
 #include <asm/microcode.h>
+#include <asm/kasan.h>
 
 /*
  * Manage page tables very early on.
@@ -46,7 +47,7 @@ static void __init reset_early_page_tables(void)
 
 	next_early_pgt = 0;
 
-	write_cr3(__pa(early_level4_pgt));
+	write_cr3(__pa_nodebug(early_level4_pgt));
 }
 
 /* Create a new PMD entry */
@@ -59,7 +60,7 @@ int __init early_make_pgtable(unsigned long address)
 	pmdval_t pmd, *pmd_p;
 
 	/* Invalid address or early pgt is done ?  */
-	if (physaddr >= MAXMEM || read_cr3() != __pa(early_level4_pgt))
+	if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt))
 		return -1;
 
 again:
@@ -160,6 +161,8 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
 	/* Kill off the identity-map trampoline */
 	reset_early_page_tables();
 
+	kasan_map_early_shadow(early_level4_pgt);
+
 	/* clear bss before set_intr_gate with early_idt_handler */
 	clear_bss();
 
@@ -181,6 +184,8 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
 	/* set init_level4_pgt kernel high mapping*/
 	init_level4_pgt[511] = early_level4_pgt[511];
 
+	kasan_map_early_shadow(init_level4_pgt);
+
 	x86_64_start_reservations(real_mode_data);
 }
 
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index a2dc0add72ed..f8a8406033c3 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -516,8 +516,38 @@ ENTRY(phys_base)
 	/* This must match the first entry in level2_kernel_pgt */
 	.quad   0x0000000000000000
 
+#ifdef CONFIG_KASAN
+#define FILL(VAL, COUNT)				\
+	.rept (COUNT) ;					\
+	.quad	(VAL) ;					\
+	.endr
+
+NEXT_PAGE(kasan_zero_pte)
+	FILL(kasan_zero_page - __START_KERNEL_map + _KERNPG_TABLE, 512)
+NEXT_PAGE(kasan_zero_pmd)
+	FILL(kasan_zero_pte - __START_KERNEL_map + _KERNPG_TABLE, 512)
+NEXT_PAGE(kasan_zero_pud)
+	FILL(kasan_zero_pmd - __START_KERNEL_map + _KERNPG_TABLE, 512)
+
+#undef FILL
+#endif
+
+
 #include "../../x86/xen/xen-head.S"
 	
 	__PAGE_ALIGNED_BSS
 NEXT_PAGE(empty_zero_page)
 	.skip PAGE_SIZE
+
+#ifdef CONFIG_KASAN
+/*
+ * This page used as early shadow. We don't use empty_zero_page
+ * at early stages, stack instrumentation could write some garbage
+ * to this page.
+ * Latter we reuse it as zero shadow for large ranges of memory
+ * that allowed to access, but not instrumented by kasan
+ * (vmalloc/vmemmap ...).
+ */
+NEXT_PAGE(kasan_zero_page)
+	.skip PAGE_SIZE
+#endif
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index e69f9882bf95..d1ac80b72c72 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -24,6 +24,7 @@
 #include <linux/fs.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
+#include <linux/kasan.h>
 #include <linux/bug.h>
 #include <linux/mm.h>
 #include <linux/gfp.h>
@@ -83,13 +84,22 @@ static unsigned long int get_module_load_offset(void)
 
 void *module_alloc(unsigned long size)
 {
+	void *p;
+
 	if (PAGE_ALIGN(size) > MODULES_LEN)
 		return NULL;
-	return __vmalloc_node_range(size, 1,
+
+	p = __vmalloc_node_range(size, MODULE_ALIGN,
 				    MODULES_VADDR + get_module_load_offset(),
 				    MODULES_END, GFP_KERNEL | __GFP_HIGHMEM,
-				    PAGE_KERNEL_EXEC, NUMA_NO_NODE,
+				    PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
 				    __builtin_return_address(0));
+	if (p && (kasan_module_alloc(p, size) < 0)) {
+		vfree(p);
+		return NULL;
+	}
+
+	return p;
 }
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 87b6496a32f1..28a850625672 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -89,6 +89,7 @@
 #include <asm/cacheflush.h>
 #include <asm/processor.h>
 #include <asm/bugs.h>
+#include <asm/kasan.h>
 
 #include <asm/vsyscall.h>
 #include <asm/cpu.h>
@@ -1174,6 +1175,8 @@ void __init setup_arch(char **cmdline_p)
 
 	x86_init.paging.pagetable_init();
 
+	kasan_init();
+
 	if (boot_cpu_data.cpuid_level >= 0) {
 		/* A CPU has %cr4 if and only if it has CPUID */
 		mmu_cr4_features = __read_cr4();
diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c
index 040681928e9d..37d8fa4438f0 100644
--- a/arch/x86/kernel/x8664_ksyms_64.c
+++ b/arch/x86/kernel/x8664_ksyms_64.c
@@ -50,13 +50,19 @@ EXPORT_SYMBOL(csum_partial);
 #undef memset
 #undef memmove
 
+extern void *__memset(void *, int, __kernel_size_t);
+extern void *__memcpy(void *, const void *, __kernel_size_t);
+extern void *__memmove(void *, const void *, __kernel_size_t);
 extern void *memset(void *, int, __kernel_size_t);
 extern void *memcpy(void *, const void *, __kernel_size_t);
-extern void *__memcpy(void *, const void *, __kernel_size_t);
+extern void *memmove(void *, const void *, __kernel_size_t);
+
+EXPORT_SYMBOL(__memset);
+EXPORT_SYMBOL(__memcpy);
+EXPORT_SYMBOL(__memmove);
 
 EXPORT_SYMBOL(memset);
 EXPORT_SYMBOL(memcpy);
-EXPORT_SYMBOL(__memcpy);
 EXPORT_SYMBOL(memmove);
 
 #ifndef CONFIG_DEBUG_VIRTUAL
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 56313a326188..89b53c9968e7 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -53,6 +53,8 @@
 .Lmemcpy_e_e:
 	.previous
 
+.weak memcpy
+
 ENTRY(__memcpy)
 ENTRY(memcpy)
 	CFI_STARTPROC
@@ -199,8 +201,8 @@ ENDPROC(__memcpy)
 	 * only outcome...
 	 */
 	.section .altinstructions, "a"
-	altinstruction_entry memcpy,.Lmemcpy_c,X86_FEATURE_REP_GOOD,\
+	altinstruction_entry __memcpy,.Lmemcpy_c,X86_FEATURE_REP_GOOD,\
 			     .Lmemcpy_e-.Lmemcpy_c,.Lmemcpy_e-.Lmemcpy_c
-	altinstruction_entry memcpy,.Lmemcpy_c_e,X86_FEATURE_ERMS, \
+	altinstruction_entry __memcpy,.Lmemcpy_c_e,X86_FEATURE_ERMS, \
 			     .Lmemcpy_e_e-.Lmemcpy_c_e,.Lmemcpy_e_e-.Lmemcpy_c_e
 	.previous
diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S
index 65268a6104f4..9c4b530575da 100644
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -24,7 +24,10 @@
  * Output:
  * rax: dest
  */
+.weak memmove
+
 ENTRY(memmove)
+ENTRY(__memmove)
 	CFI_STARTPROC
 
 	/* Handle more 32 bytes in loop */
@@ -220,4 +223,5 @@ ENTRY(memmove)
 		.Lmemmove_end_forward-.Lmemmove_begin_forward,	\
 		.Lmemmove_end_forward_efs-.Lmemmove_begin_forward_efs
 	.previous
+ENDPROC(__memmove)
 ENDPROC(memmove)
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index 2dcb3808cbda..6f44935c6a60 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -56,6 +56,8 @@
 .Lmemset_e_e:
 	.previous
 
+.weak memset
+
 ENTRY(memset)
 ENTRY(__memset)
 	CFI_STARTPROC
@@ -147,8 +149,8 @@ ENDPROC(__memset)
          * feature to implement the right patch order.
 	 */
 	.section .altinstructions,"a"
-	altinstruction_entry memset,.Lmemset_c,X86_FEATURE_REP_GOOD,\
-			     .Lfinal-memset,.Lmemset_e-.Lmemset_c
-	altinstruction_entry memset,.Lmemset_c_e,X86_FEATURE_ERMS, \
-			     .Lfinal-memset,.Lmemset_e_e-.Lmemset_c_e
+	altinstruction_entry __memset,.Lmemset_c,X86_FEATURE_REP_GOOD,\
+			     .Lfinal-__memset,.Lmemset_e-.Lmemset_c
+	altinstruction_entry __memset,.Lmemset_c_e,X86_FEATURE_ERMS, \
+			     .Lfinal-__memset,.Lmemset_e_e-.Lmemset_c_e
 	.previous
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 6a19ad9f370d..9648838b78fa 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -20,6 +20,9 @@ obj-$(CONFIG_HIGHMEM)		+= highmem_32.o
 
 obj-$(CONFIG_KMEMCHECK)		+= kmemcheck/
 
+KASAN_SANITIZE_kasan_init_$(BITS).o := n
+obj-$(CONFIG_KASAN)		+= kasan_init_$(BITS).o
+
 obj-$(CONFIG_MMIOTRACE)		+= mmiotrace.o
 mmiotrace-y			:= kmmio.o pf_in.o mmio-mod.o
 obj-$(CONFIG_MMIOTRACE_TEST)	+= testmmiotrace.o
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
new file mode 100644
index 000000000000..23dc7673e110
--- /dev/null
+++ b/arch/x86/mm/kasan_init_64.c
@@ -0,0 +1,209 @@
+#include <linux/bootmem.h>
+#include <linux/kasan.h>
+#include <linux/kdebug.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+
+extern pgd_t early_level4_pgt[PTRS_PER_PGD];
+extern struct range pfn_mapped[E820_X_MAX];
+
+extern unsigned char kasan_zero_page[PAGE_SIZE];
+
+static int __init map_range(struct range *range)
+{
+	unsigned long start;
+	unsigned long end;
+
+	start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start));
+	end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end));
+
+	/*
+	 * end + 1 here is intentional. We check several shadow bytes in advance
+	 * to slightly speed up fastpath. In some rare cases we could cross
+	 * boundary of mapped shadow, so we just map some more here.
+	 */
+	return vmemmap_populate(start, end + 1, NUMA_NO_NODE);
+}
+
+static void __init clear_pgds(unsigned long start,
+			unsigned long end)
+{
+	for (; start < end; start += PGDIR_SIZE)
+		pgd_clear(pgd_offset_k(start));
+}
+
+void __init kasan_map_early_shadow(pgd_t *pgd)
+{
+	int i;
+	unsigned long start = KASAN_SHADOW_START;
+	unsigned long end = KASAN_SHADOW_END;
+
+	for (i = pgd_index(start); start < end; i++) {
+		pgd[i] = __pgd(__pa_nodebug(kasan_zero_pud)
+				| _KERNPG_TABLE);
+		start += PGDIR_SIZE;
+	}
+}
+
+static int __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
+				unsigned long end)
+{
+	pte_t *pte = pte_offset_kernel(pmd, addr);
+
+	while (addr + PAGE_SIZE <= end) {
+		WARN_ON(!pte_none(*pte));
+		set_pte(pte, __pte(__pa_nodebug(kasan_zero_page)
+					| __PAGE_KERNEL_RO));
+		addr += PAGE_SIZE;
+		pte = pte_offset_kernel(pmd, addr);
+	}
+	return 0;
+}
+
+static int __init zero_pmd_populate(pud_t *pud, unsigned long addr,
+				unsigned long end)
+{
+	int ret = 0;
+	pmd_t *pmd = pmd_offset(pud, addr);
+
+	while (IS_ALIGNED(addr, PMD_SIZE) && addr + PMD_SIZE <= end) {
+		WARN_ON(!pmd_none(*pmd));
+		set_pmd(pmd, __pmd(__pa_nodebug(kasan_zero_pte)
+					| __PAGE_KERNEL_RO));
+		addr += PMD_SIZE;
+		pmd = pmd_offset(pud, addr);
+	}
+	if (addr < end) {
+		if (pmd_none(*pmd)) {
+			void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
+			if (!p)
+				return -ENOMEM;
+			set_pmd(pmd, __pmd(__pa_nodebug(p) | _KERNPG_TABLE));
+		}
+		ret = zero_pte_populate(pmd, addr, end);
+	}
+	return ret;
+}
+
+
+static int __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
+				unsigned long end)
+{
+	int ret = 0;
+	pud_t *pud = pud_offset(pgd, addr);
+
+	while (IS_ALIGNED(addr, PUD_SIZE) && addr + PUD_SIZE <= end) {
+		WARN_ON(!pud_none(*pud));
+		set_pud(pud, __pud(__pa_nodebug(kasan_zero_pmd)
+					| __PAGE_KERNEL_RO));
+		addr += PUD_SIZE;
+		pud = pud_offset(pgd, addr);
+	}
+
+	if (addr < end) {
+		if (pud_none(*pud)) {
+			void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
+			if (!p)
+				return -ENOMEM;
+			set_pud(pud, __pud(__pa_nodebug(p) | _KERNPG_TABLE));
+		}
+		ret = zero_pmd_populate(pud, addr, end);
+	}
+	return ret;
+}
+
+static int __init zero_pgd_populate(unsigned long addr, unsigned long end)
+{
+	int ret = 0;
+	pgd_t *pgd = pgd_offset_k(addr);
+
+	while (IS_ALIGNED(addr, PGDIR_SIZE) && addr + PGDIR_SIZE <= end) {
+		WARN_ON(!pgd_none(*pgd));
+		set_pgd(pgd, __pgd(__pa_nodebug(kasan_zero_pud)
+					| __PAGE_KERNEL_RO));
+		addr += PGDIR_SIZE;
+		pgd = pgd_offset_k(addr);
+	}
+
+	if (addr < end) {
+		if (pgd_none(*pgd)) {
+			void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
+			if (!p)
+				return -ENOMEM;
+			set_pgd(pgd, __pgd(__pa_nodebug(p) | _KERNPG_TABLE));
+		}
+		ret = zero_pud_populate(pgd, addr, end);
+	}
+	return ret;
+}
+
+
+static void __init populate_zero_shadow(const void *start, const void *end)
+{
+	if (zero_pgd_populate((unsigned long)start, (unsigned long)end))
+		panic("kasan: unable to map zero shadow!");
+}
+
+
+#ifdef CONFIG_KASAN_INLINE
+static int kasan_die_handler(struct notifier_block *self,
+			     unsigned long val,
+			     void *data)
+{
+	if (val == DIE_GPF) {
+		pr_emerg("CONFIG_KASAN_INLINE enabled");
+		pr_emerg("GPF could be caused by NULL-ptr deref or user memory access");
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block kasan_die_notifier = {
+	.notifier_call = kasan_die_handler,
+};
+#endif
+
+void __init kasan_init(void)
+{
+	int i;
+
+#ifdef CONFIG_KASAN_INLINE
+	register_die_notifier(&kasan_die_notifier);
+#endif
+
+	memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt));
+	load_cr3(early_level4_pgt);
+
+	clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+	kasan_populate_zero_shadow((void *)KASAN_SHADOW_START,
+			kasan_mem_to_shadow((void *)PAGE_OFFSET));
+
+	for (i = 0; i < E820_X_MAX; i++) {
+		if (pfn_mapped[i].end == 0)
+			break;
+
+		if (map_range(&pfn_mapped[i]))
+			panic("kasan: unable to allocate shadow!");
+	}
+	kasan_populate_zero_shadow(
+		kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
+		kasan_mem_to_shadow((void *)__START_KERNEL_map));
+
+	vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
+			(unsigned long)kasan_mem_to_shadow(_end),
+			NUMA_NO_NODE);
+
+	kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
+			(void *)KASAN_SHADOW_END);
+
+	memset(kasan_zero_page, 0, PAGE_SIZE);
+
+	load_cr3(init_level4_pgt);
+	init_task.kasan_depth = 0;
+
+	pr_info("KernelAddressSanitizer initialized\n");
+}
diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile
index 94f7fbe97b08..e02c2c6c56a5 100644
--- a/arch/x86/realmode/Makefile
+++ b/arch/x86/realmode/Makefile
@@ -6,7 +6,7 @@
 # for more details.
 #
 #
-
+KASAN_SANITIZE := n
 subdir- := rm
 
 obj-y += init.o
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index 7c0d7be176a5..2730d775ef9a 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -6,6 +6,7 @@
 # for more details.
 #
 #
+KASAN_SANITIZE := n
 
 always := realmode.bin realmode.relocs
 
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index 5a4affe025e8..2aacd7c63c7b 100644
--- a/arch/x86/vdso/Makefile
+++ b/arch/x86/vdso/Makefile
@@ -3,6 +3,7 @@
 #
 
 KBUILD_CFLAGS += $(DISABLE_LTO)
+KASAN_SANITIZE := n
 
 VDSO64-$(CONFIG_X86_64)		:= y
 VDSOX32-$(CONFIG_X86_X32_ABI)	:= y