[patch 35/60] kasan, arm64: expand CONFIG_KASAN checks

[Andrew Morton <akpm@linux-foundation.org>]

From: Andrey Konovalov <andreyknvl@google.com>
Subject: kasan, arm64: expand CONFIG_KASAN checks

Some #ifdef CONFIG_KASAN checks are only relevant for software KASAN modes
(either related to shadow memory or compiler instrumentation).  Expand
those into CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS.

Link: https://lkml.kernel.org/r/e6971e432dbd72bb897ff14134ebb7e169bdcf0c.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/arm64/Kconfig                 |    2 +-
 arch/arm64/Makefile                |    2 +-
 arch/arm64/include/asm/assembler.h |    2 +-
 arch/arm64/include/asm/memory.h    |    2 +-
 arch/arm64/include/asm/string.h    |    5 +++--
 arch/arm64/kernel/head.S           |    2 +-
 arch/arm64/kernel/image-vars.h     |    2 +-
 arch/arm64/kernel/kaslr.c          |    3 ++-
 arch/arm64/kernel/module.c         |    6 ++++--
 arch/arm64/mm/ptdump.c             |    6 +++---
 include/linux/kasan-checks.h       |    2 +-
 include/linux/kasan.h              |    7 ++++---
 include/linux/moduleloader.h       |    3 ++-
 include/linux/string.h             |    2 +-
 mm/ptdump.c                        |   13 ++++++++-----
 scripts/Makefile.lib               |    2 ++
 16 files changed, 36 insertions(+), 25 deletions(-)

--- a/arch/arm64/include/asm/assembler.h~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/include/asm/assembler.h
@@ -473,7 +473,7 @@ USER(\label, ic	ivau, \tmp2)			// invali
 #define NOKPROBE(x)
 #endif
 
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 #define EXPORT_SYMBOL_NOKASAN(name)
 #else
 #define EXPORT_SYMBOL_NOKASAN(name)	EXPORT_SYMBOL(name)
--- a/arch/arm64/include/asm/memory.h~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/include/asm/memory.h
@@ -72,7 +72,7 @@
  * address space for the shadow region respectively. They can bloat the stack
  * significantly, so double the (minimum) stack size when they are in use.
  */
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 #define KASAN_SHADOW_OFFSET	_AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
 #define KASAN_SHADOW_END	((UL(1) << (64 - KASAN_SHADOW_SCALE_SHIFT)) \
 					+ KASAN_SHADOW_OFFSET)
--- a/arch/arm64/include/asm/string.h~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/include/asm/string.h
@@ -5,7 +5,7 @@
 #ifndef __ASM_STRING_H
 #define __ASM_STRING_H
 
-#ifndef CONFIG_KASAN
+#if !(defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
 #define __HAVE_ARCH_STRRCHR
 extern char *strrchr(const char *, int c);
 
@@ -48,7 +48,8 @@ extern void *__memset(void *, int, __ker
 void memcpy_flushcache(void *dst, const void *src, size_t cnt);
 #endif
 
-#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
+#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
+	!defined(__SANITIZE_ADDRESS__)
 
 /*
  * For files that are not instrumented (e.g. mm/slub.c) we
--- a/arch/arm64/Kconfig~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/Kconfig
@@ -334,7 +334,7 @@ config BROKEN_GAS_INST
 
 config KASAN_SHADOW_OFFSET
 	hex
-	depends on KASAN
+	depends on KASAN_GENERIC || KASAN_SW_TAGS
 	default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
 	default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
 	default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
--- a/arch/arm64/kernel/head.S~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/kernel/head.S
@@ -433,7 +433,7 @@ SYM_FUNC_START_LOCAL(__primary_switched)
 	bl	__pi_memset
 	dsb	ishst				// Make zero page visible to PTW
 
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 	bl	kasan_early_init
 #endif
 #ifdef CONFIG_RANDOMIZE_BASE
--- a/arch/arm64/kernel/image-vars.h~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/kernel/image-vars.h
@@ -37,7 +37,7 @@ __efistub_strncmp		= __pi_strncmp;
 __efistub_strrchr		= __pi_strrchr;
 __efistub___clean_dcache_area_poc = __pi___clean_dcache_area_poc;
 
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 __efistub___memcpy		= __pi_memcpy;
 __efistub___memmove		= __pi_memmove;
 __efistub___memset		= __pi_memset;
--- a/arch/arm64/kernel/kaslr.c~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/kernel/kaslr.c
@@ -161,7 +161,8 @@ u64 __init kaslr_early_init(u64 dt_phys)
 	/* use the top 16 bits to randomize the linear region */
 	memstart_offset_seed = seed >> 48;
 
-	if (IS_ENABLED(CONFIG_KASAN))
+	if (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
+	    IS_ENABLED(CONFIG_KASAN_SW_TAGS))
 		/*
 		 * KASAN does not expect the module region to intersect the
 		 * vmalloc region, since shadow memory is allocated for each
--- a/arch/arm64/kernel/module.c~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/kernel/module.c
@@ -30,7 +30,8 @@ void *module_alloc(unsigned long size)
 	if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
 		gfp_mask |= __GFP_NOWARN;
 
-	if (IS_ENABLED(CONFIG_KASAN))
+	if (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
+	    IS_ENABLED(CONFIG_KASAN_SW_TAGS))
 		/* don't exceed the static module region - see below */
 		module_alloc_end = MODULES_END;
 
@@ -39,7 +40,8 @@ void *module_alloc(unsigned long size)
 				NUMA_NO_NODE, __builtin_return_address(0));
 
 	if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
-	    !IS_ENABLED(CONFIG_KASAN))
+	    !IS_ENABLED(CONFIG_KASAN_GENERIC) &&
+	    !IS_ENABLED(CONFIG_KASAN_SW_TAGS))
 		/*
 		 * KASAN can only deal with module allocations being served
 		 * from the reserved module region, since the remainder of
--- a/arch/arm64/Makefile~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/Makefile
@@ -137,7 +137,7 @@ head-y		:= arch/arm64/kernel/head.o
 
 ifeq ($(CONFIG_KASAN_SW_TAGS), y)
 KASAN_SHADOW_SCALE_SHIFT := 4
-else
+else ifeq ($(CONFIG_KASAN_GENERIC), y)
 KASAN_SHADOW_SCALE_SHIFT := 3
 endif
 
--- a/arch/arm64/mm/ptdump.c~kasan-arm64-expand-config_kasan-checks
+++ a/arch/arm64/mm/ptdump.c
@@ -29,7 +29,7 @@
 enum address_markers_idx {
 	PAGE_OFFSET_NR = 0,
 	PAGE_END_NR,
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 	KASAN_START_NR,
 #endif
 };
@@ -37,7 +37,7 @@ enum address_markers_idx {
 static struct addr_marker address_markers[] = {
 	{ PAGE_OFFSET,			"Linear Mapping start" },
 	{ 0 /* PAGE_END */,		"Linear Mapping end" },
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 	{ 0 /* KASAN_SHADOW_START */,	"Kasan shadow start" },
 	{ KASAN_SHADOW_END,		"Kasan shadow end" },
 #endif
@@ -383,7 +383,7 @@ void ptdump_check_wx(void)
 static int ptdump_init(void)
 {
 	address_markers[PAGE_END_NR].start_address = PAGE_END;
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 	address_markers[KASAN_START_NR].start_address = KASAN_SHADOW_START;
 #endif
 	ptdump_initialize();
--- a/include/linux/kasan-checks.h~kasan-arm64-expand-config_kasan-checks
+++ a/include/linux/kasan-checks.h
@@ -9,7 +9,7 @@
  * even in compilation units that selectively disable KASAN, but must use KASAN
  * to validate access to an address.   Never use these in header files!
  */
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 bool __kasan_check_read(const volatile void *p, unsigned int size);
 bool __kasan_check_write(const volatile void *p, unsigned int size);
 #else
--- a/include/linux/kasan.h~kasan-arm64-expand-config_kasan-checks
+++ a/include/linux/kasan.h
@@ -238,7 +238,8 @@ static inline void kasan_release_vmalloc
 
 #endif /* CONFIG_KASAN_VMALLOC */
 
-#if defined(CONFIG_KASAN) && !defined(CONFIG_KASAN_VMALLOC)
+#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
+		!defined(CONFIG_KASAN_VMALLOC)
 
 /*
  * These functions provide a special case to support backing module
@@ -248,12 +249,12 @@ static inline void kasan_release_vmalloc
 int kasan_module_alloc(void *addr, size_t size);
 void kasan_free_shadow(const struct vm_struct *vm);
 
-#else /* CONFIG_KASAN && !CONFIG_KASAN_VMALLOC */
+#else /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
 
 static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
 static inline void kasan_free_shadow(const struct vm_struct *vm) {}
 
-#endif /* CONFIG_KASAN && !CONFIG_KASAN_VMALLOC */
+#endif /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
 
 #ifdef CONFIG_KASAN_INLINE
 void kasan_non_canonical_hook(unsigned long addr);
--- a/include/linux/moduleloader.h~kasan-arm64-expand-config_kasan-checks
+++ a/include/linux/moduleloader.h
@@ -96,7 +96,8 @@ void module_arch_cleanup(struct module *
 /* Any cleanup before freeing mod->module_init */
 void module_arch_freeing_init(struct module *mod);
 
-#if defined(CONFIG_KASAN) && !defined(CONFIG_KASAN_VMALLOC)
+#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
+		!defined(CONFIG_KASAN_VMALLOC)
 #include <linux/kasan.h>
 #define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
 #else
--- a/include/linux/string.h~kasan-arm64-expand-config_kasan-checks
+++ a/include/linux/string.h
@@ -267,7 +267,7 @@ void __write_overflow(void) __compiletim
 
 #if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
 
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp);
 extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy);
--- a/mm/ptdump.c~kasan-arm64-expand-config_kasan-checks
+++ a/mm/ptdump.c
@@ -4,7 +4,7 @@
 #include <linux/ptdump.h>
 #include <linux/kasan.h>
 
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 /*
  * This is an optimization for KASAN=y case. Since all kasan page tables
  * eventually point to the kasan_early_shadow_page we could call note_page()
@@ -31,7 +31,8 @@ static int ptdump_pgd_entry(pgd_t *pgd,
 	struct ptdump_state *st = walk->private;
 	pgd_t val = READ_ONCE(*pgd);
 
-#if CONFIG_PGTABLE_LEVELS > 4 && defined(CONFIG_KASAN)
+#if CONFIG_PGTABLE_LEVELS > 4 && \
+		(defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
 	if (pgd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_p4d)))
 		return note_kasan_page_table(walk, addr);
 #endif
@@ -51,7 +52,8 @@ static int ptdump_p4d_entry(p4d_t *p4d,
 	struct ptdump_state *st = walk->private;
 	p4d_t val = READ_ONCE(*p4d);
 
-#if CONFIG_PGTABLE_LEVELS > 3 && defined(CONFIG_KASAN)
+#if CONFIG_PGTABLE_LEVELS > 3 && \
+		(defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
 	if (p4d_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pud)))
 		return note_kasan_page_table(walk, addr);
 #endif
@@ -71,7 +73,8 @@ static int ptdump_pud_entry(pud_t *pud,
 	struct ptdump_state *st = walk->private;
 	pud_t val = READ_ONCE(*pud);
 
-#if CONFIG_PGTABLE_LEVELS > 2 && defined(CONFIG_KASAN)
+#if CONFIG_PGTABLE_LEVELS > 2 && \
+		(defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
 	if (pud_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pmd)))
 		return note_kasan_page_table(walk, addr);
 #endif
@@ -91,7 +94,7 @@ static int ptdump_pmd_entry(pmd_t *pmd,
 	struct ptdump_state *st = walk->private;
 	pmd_t val = READ_ONCE(*pmd);
 
-#if defined(CONFIG_KASAN)
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 	if (pmd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pte)))
 		return note_kasan_page_table(walk, addr);
 #endif
--- a/scripts/Makefile.lib~kasan-arm64-expand-config_kasan-checks
+++ a/scripts/Makefile.lib
@@ -148,10 +148,12 @@ endif
 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
 #
 ifeq ($(CONFIG_KASAN),y)
+ifneq ($(CONFIG_KASAN_HW_TAGS),y)
 _c_flags += $(if $(patsubst n%,, \
 		$(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
 		$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
 endif
+endif
 
 ifeq ($(CONFIG_UBSAN),y)
 _c_flags += $(if $(patsubst n%,, \
_