Commit 8f7b5054 authored by Vincenzo Frascino's avatar Vincenzo Frascino Committed by Catalin Marinas
Browse files

kasan: Add report for async mode 



KASAN provides an asynchronous mode of execution.

Add reporting functionality for this mode.

Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Link: https://lore.kernel.org/r/20210315132019.33202-5-vincenzo.frascino@arm.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent c137c614

include/linux/kasan.h

+6 −0
Original line number Diff line number Diff line
@@ -376,6 +376,12 @@ static inline void *kasan_reset_tag(const void *addr) 


#endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/



#ifdef CONFIG_KASAN_HW_TAGS



void kasan_report_async(void);



#endif /* CONFIG_KASAN_HW_TAGS */



#ifdef CONFIG_KASAN_SW_TAGS

void __init kasan_init_sw_tags(void);

#else

mm/kasan/kasan.h

+16 −0
Original line number Diff line number Diff line
@@ -7,17 +7,33 @@ 
#include <linux/stackdepot.h>



#ifdef CONFIG_KASAN_HW_TAGS



#include <linux/static_key.h>



DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace);

extern bool kasan_flag_async __ro_after_init;



static inline bool kasan_stack_collection_enabled(void)

{

	return static_branch_unlikely(&kasan_flag_stacktrace);

}



static inline bool kasan_async_mode_enabled(void)

{

	return kasan_flag_async;

}

#else



static inline bool kasan_stack_collection_enabled(void)

{

	return true;

}



static inline bool kasan_async_mode_enabled(void)

{

	return false;

}



#endif



extern bool kasan_flag_panic __ro_after_init;

mm/kasan/report.c

+16 −1
Original line number Diff line number Diff line
@@ -87,6 +87,7 @@ static void start_report(unsigned long *flags) 


static void end_report(unsigned long *flags, unsigned long addr)

{

	if (!kasan_async_mode_enabled())

		trace_error_report_end(ERROR_DETECTOR_KASAN, addr);

	pr_err("==================================================================\n");

	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
@@ -360,6 +361,20 @@ void kasan_report_invalid_free(void *object, unsigned long ip) 
	end_report(&flags, (unsigned long)object);

}



#ifdef CONFIG_KASAN_HW_TAGS

void kasan_report_async(void)

{

	unsigned long flags;



	start_report(&flags);

	pr_err("BUG: KASAN: invalid-access\n");

	pr_err("Asynchronous mode enabled: no access details available\n");

	pr_err("\n");

	dump_stack();

	end_report(&flags, 0);

}

#endif /* CONFIG_KASAN_HW_TAGS */



static void __kasan_report(unsigned long addr, size_t size, bool is_write,

				unsigned long ip)

{