Commit 9d7b7dd9 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds
Browse files

kasan: split out print_report from __kasan_report 

Split out the part of __kasan_report() that prints things into
print_report().  One of the subsequent patches makes another error handler
use print_report() as well.

Includes lower-level changes:

 - Allow addr_has_metadata() accepting a tagged address.

 - Drop the const qualifier from the fields of kasan_access_info to
   avoid excessive type casts.

 - Change the type of the address argument of __kasan_report() and
   end_report() to void * to reduce the number of type casts.

Link: https://lkml.kernel.org/r/9be3ed99dd24b9c4e1c4a848b69a0c6ecefd845e.1646237226.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0a6e8a07

mm/kasan/kasan.h

+4 −3
Original line number Diff line number Diff line
@@ -128,8 +128,8 @@ static inline bool kasan_sync_fault_possible(void) 
#define META_ROWS_AROUND_ADDR 2



struct kasan_access_info {

	const void *access_addr;

	const void *first_bad_addr;

	void *access_addr;

	void *first_bad_addr;

	size_t access_size;

	bool is_write;

	unsigned long ip;
@@ -239,7 +239,8 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr) 


static inline bool addr_has_metadata(const void *addr)

{

	return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));

	return (kasan_reset_tag(addr) >=

		kasan_shadow_to_mem((void *)KASAN_SHADOW_START));

}



/**

mm/kasan/report.c

+31 −27
Original line number Diff line number Diff line
@@ -139,10 +139,11 @@ static void start_report(unsigned long *flags, bool sync) 
	pr_err("==================================================================\n");

}



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

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

{

	if (addr)

		trace_error_report_end(ERROR_DETECTOR_KASAN, addr);

		trace_error_report_end(ERROR_DETECTOR_KASAN,

				       (unsigned long)addr);

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

	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);

	spin_unlock_irqrestore(&report_lock, *flags);
@@ -398,7 +399,7 @@ void kasan_report_invalid_free(void *object, unsigned long ip) 
	pr_err("\n");

	print_address_description(object, tag);

	print_memory_metadata(object);

	end_report(&flags, (unsigned long)object);

	end_report(&flags, object);

}



#ifdef CONFIG_KASAN_HW_TAGS
@@ -411,44 +412,47 @@ void kasan_report_async(void) 
	pr_err("Asynchronous mode enabled: no access details available\n");

	pr_err("\n");

	dump_stack_lvl(KERN_ERR);

	end_report(&flags, 0);

	end_report(&flags, NULL);

}

#endif /* CONFIG_KASAN_HW_TAGS */



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

static void print_report(struct kasan_access_info *info)

{

	void *tagged_addr = info->access_addr;

	void *untagged_addr = kasan_reset_tag(tagged_addr);

	u8 tag = get_tag(tagged_addr);



	print_error_description(info);

	if (addr_has_metadata(untagged_addr))

		kasan_print_tags(tag, info->first_bad_addr);

	pr_err("\n");



	if (addr_has_metadata(untagged_addr)) {

		print_address_description(untagged_addr, tag);

		print_memory_metadata(info->first_bad_addr);

	} else {

		dump_stack_lvl(KERN_ERR);

	}

}



static void __kasan_report(void *addr, size_t size, bool is_write,

				unsigned long ip)

{

	struct kasan_access_info info;

	void *tagged_addr;

	void *untagged_addr;

	unsigned long flags;



	start_report(&flags, true);



	tagged_addr = (void *)addr;

	untagged_addr = kasan_reset_tag(tagged_addr);



	info.access_addr = tagged_addr;

	if (addr_has_metadata(untagged_addr))

		info.first_bad_addr =

			kasan_find_first_bad_addr(tagged_addr, size);

	info.access_addr = addr;

	if (addr_has_metadata(addr))

		info.first_bad_addr = kasan_find_first_bad_addr(addr, size);

	else

		info.first_bad_addr = untagged_addr;

		info.first_bad_addr = addr;

	info.access_size = size;

	info.is_write = is_write;

	info.ip = ip;



	print_error_description(&info);

	if (addr_has_metadata(untagged_addr))

		kasan_print_tags(get_tag(tagged_addr), info.first_bad_addr);

	pr_err("\n");



	if (addr_has_metadata(untagged_addr)) {

		print_address_description(untagged_addr, get_tag(tagged_addr));

		print_memory_metadata(info.first_bad_addr);

	} else {

		dump_stack_lvl(KERN_ERR);

	}

	print_report(&info);



	end_report(&flags, addr);

}
@@ -460,7 +464,7 @@ bool kasan_report(unsigned long addr, size_t size, bool is_write, 
	bool ret = false;



	if (likely(report_enabled())) {

		__kasan_report(addr, size, is_write, ip);

		__kasan_report((void *)addr, size, is_write, ip);

		ret = true;

	}