[PATCH v3 34/39] kasan, arm64: expand CONFIG_KASAN checks

Andrey Konovalov
2020-09-24T22:52:26Z

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.

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>
---
Change-Id: I91e661e2c1627783cb845d877c6371dfc8779505
---
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/mm/dump.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 ++
14 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 192544fcd1a5..e28d49cc1400 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -320,7 +320,7 @@ config BROKEN_GAS_INST

config KASAN_SHADOW_OFFSET
hex
- depends on KASAN
+ depends on KASAN_GENERIC || KASAN_SW_TAGS
default 0xdfffa00000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS
default 0xdfffd00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS
default 0xdffffe8000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index afcd61f7d2b0..af556bfec5c3 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -142,7 +142,7 @@ TEXT_OFFSET := 0x0

ifeq ($(CONFIG_KASAN_SW_TAGS), y)
KASAN_SHADOW_SCALE_SHIFT := 4
-else
+else ifeq ($(CONFIG_KASAN_GENERIC), y)
KASAN_SHADOW_SCALE_SHIFT := 3
endif

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 54d181177656..bc9ace1e5f3a 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -464,7 +464,7 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU
#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)
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 268a3b6cebd2..de9af7bea90d 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/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)
diff --git a/arch/arm64/include/asm/string.h b/arch/arm64/include/asm/string.h
index b31e8e87a0db..3a3264ff47b9 100644
--- a/arch/arm64/include/asm/string.h
+++ b/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, __kernel_size_t);
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
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 037421c66b14..427ded9e68e8 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -452,7 +452,7 @@ 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
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 8982b68289b7..ed8d086d601c 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/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;
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index ba6d1d89f9b2..bf8ddeac5d8f 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.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
@@ -381,7 +381,7 @@ 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();
diff --git a/include/linux/kasan-checks.h b/include/linux/kasan-checks.h
index ac6aba632f2d..ca5e89fb10d3 100644
--- a/include/linux/kasan-checks.h
+++ b/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
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 4ca1b9970201..94b974f15892 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -226,7 +226,8 @@ static inline void kasan_release_vmalloc(unsigned long start,

#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
@@ -236,12 +237,12 @@ static inline void kasan_release_vmalloc(unsigned long start,
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);
diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
index 4fa67a8b2265..9e09d11ffe5b 100644
--- a/include/linux/moduleloader.h
+++ b/include/linux/moduleloader.h
@@ -96,7 +96,8 @@ void module_arch_cleanup(struct module *mod);
/* 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
diff --git a/include/linux/string.h b/include/linux/string.h
index 9b7a0632e87a..607322616363 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -273,7 +273,7 @@ void __write_overflow(void) __compiletime_error("detected write beyond size of o

#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);
diff --git a/mm/ptdump.c b/mm/ptdump.c
index ba88ec43ff21..4354c1422d57 100644
--- a/mm/ptdump.c
+++ b/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, unsigned long addr,
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, unsigned long addr,
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, unsigned long addr,
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, unsigned long addr,
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
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 3d599716940c..dc2d13c4455a 100644
--- a/scripts/Makefile.lib
+++ b/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%,, \
--
2.28.0.681.g6f77f65b4e-goog