Commit d73b4936 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds
Browse files

kasan, arm64: only use kasan_depth for software modes 

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Hardware tag-based KASAN won't use kasan_depth.  Only define and use it
when one of the software KASAN modes are enabled.

No functional changes for software modes.

Link: https://lkml.kernel.org/r/e16f15aeda90bc7fb4dfc2e243a14b74cc5c8219.1606161801.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarAlexander Potapenko <glider@google.com>
Tested-by: default avatarVincenzo 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent afe6ef80

arch/arm64/mm/kasan_init.c

+8 −3
Original line number Diff line number Diff line
@@ -273,17 +273,22 @@ static void __init kasan_init_shadow(void) 
	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));

}



static void __init kasan_init_depth(void)

{

	init_task.kasan_depth = 0;

}



#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */



static inline void __init kasan_init_shadow(void) { }



static inline void __init kasan_init_depth(void) { }



#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */



void __init kasan_init(void)

{

	kasan_init_shadow();



	/* At this point kasan is fully initialized. Enable error messages */

	init_task.kasan_depth = 0;

	kasan_init_depth();

	pr_info("KernelAddressSanitizer initialized\n");

}

include/linux/kasan.h

+9 −9
Original line number Diff line number Diff line
@@ -52,6 +52,12 @@ static inline void *kasan_mem_to_shadow(const void *addr) 
int kasan_add_zero_shadow(void *start, unsigned long size);

void kasan_remove_zero_shadow(void *start, unsigned long size);



/* Enable reporting bugs after kasan_disable_current() */

extern void kasan_enable_current(void);



/* Disable reporting bugs for current task */

extern void kasan_disable_current(void);



#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */



static inline int kasan_add_zero_shadow(void *start, unsigned long size)
@@ -62,16 +68,13 @@ static inline void kasan_remove_zero_shadow(void *start, 
					unsigned long size)

{}



static inline void kasan_enable_current(void) {}

static inline void kasan_disable_current(void) {}



#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */



#ifdef CONFIG_KASAN



/* Enable reporting bugs after kasan_disable_current() */

extern void kasan_enable_current(void);



/* Disable reporting bugs for current task */

extern void kasan_disable_current(void);



void kasan_unpoison_range(const void *address, size_t size);



void kasan_unpoison_task_stack(struct task_struct *task);
@@ -122,9 +125,6 @@ static inline void kasan_unpoison_range(const void *address, size_t size) {} 


static inline void kasan_unpoison_task_stack(struct task_struct *task) {}



static inline void kasan_enable_current(void) {}

static inline void kasan_disable_current(void) {}



static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}

static inline void kasan_free_pages(struct page *page, unsigned int order) {}

include/linux/sched.h

+1 −1
Original line number Diff line number Diff line
@@ -1234,7 +1234,7 @@ struct task_struct { 
	u64				timer_slack_ns;

	u64				default_timer_slack_ns;



#ifdef CONFIG_KASAN

#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

	unsigned int			kasan_depth;

#endif

init/init_task.c

+1 −1
Original line number Diff line number Diff line
@@ -176,7 +176,7 @@ struct task_struct init_task 
	.numa_group	= NULL,

	.numa_faults	= NULL,

#endif

#ifdef CONFIG_KASAN

#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

	.kasan_depth	= 1,

#endif

#ifdef CONFIG_KCSAN

mm/kasan/common.c

+2 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ void kasan_set_track(struct kasan_track *track, gfp_t flags) 
	track->stack = kasan_save_stack(flags);

}



#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

void kasan_enable_current(void)

{

	current->kasan_depth++;
@@ -55,6 +56,7 @@ void kasan_disable_current(void) 
{

	current->kasan_depth--;

}

#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */



void kasan_unpoison_range(const void *address, size_t size)

{