Commit 0f9b35f3 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds
Browse files

kasan: rearrange stack frame info in reports 

 - Move printing stack frame info before printing page info.

 - Add object_is_on_stack() check to print_address_description() and add
   a corresponding WARNING to kasan_print_address_stack_frame(). This
   looks more in line with the rest of the checks in this function and
   also allows to avoid complicating code logic wrt line breaks.

 - Clean up comments related to get_address_stack_frame_info().

Link: https://lkml.kernel.org/r/1ee113a4c111df97d168c820b527cda77a3cac40.1646237226.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarAlexander 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 038fd2b4

mm/kasan/report.c

+9 −3
Original line number Diff line number Diff line
@@ -259,6 +259,15 @@ static void print_address_description(void *addr, u8 tag) 
		pr_err("\n");

	}



	if (object_is_on_stack(addr)) {

		/*

		 * Currently, KASAN supports printing frame information only

		 * for accesses to the task's own stack.

		 */

		kasan_print_address_stack_frame(addr);

		pr_err("\n");

	}



	if (is_vmalloc_addr(addr)) {

		struct vm_struct *va = find_vm_area(addr);
@@ -278,9 +287,6 @@ static void print_address_description(void *addr, u8 tag) 
		dump_page(page, "kasan: bad access detected");

		pr_err("\n");

	}



	kasan_print_address_stack_frame(addr);

	pr_err("\n");

}



static bool meta_row_is_guilty(const void *row, const void *addr)

mm/kasan/report_generic.c

+4 −11
Original line number Diff line number Diff line
@@ -211,6 +211,7 @@ static void print_decoded_frame_descr(const char *frame_descr) 
	}

}



/* Returns true only if the address is on the current task's stack. */

static bool __must_check get_address_stack_frame_info(const void *addr,

						      unsigned long *offset,

						      const char **frame_descr,
@@ -224,13 +225,6 @@ static bool __must_check get_address_stack_frame_info(const void *addr, 


	BUILD_BUG_ON(IS_ENABLED(CONFIG_STACK_GROWSUP));



	/*

	 * NOTE: We currently only support printing frame information for

	 * accesses to the task's own stack.

	 */

	if (!object_is_on_stack(addr))

		return false;



	aligned_addr = round_down((unsigned long)addr, sizeof(long));

	mem_ptr = round_down(aligned_addr, KASAN_GRANULE_SIZE);

	shadow_ptr = kasan_mem_to_shadow((void *)aligned_addr);
@@ -269,14 +263,13 @@ void kasan_print_address_stack_frame(const void *addr) 
	const char *frame_descr;

	const void *frame_pc;



	if (WARN_ON(!object_is_on_stack(addr)))

		return;



	if (!get_address_stack_frame_info(addr, &offset, &frame_descr,

					  &frame_pc))

		return;



	/*

	 * get_address_stack_frame_info only returns true if the given addr is

	 * on the current task's stack.

	 */

	pr_err("\n");

	pr_err("addr %px is located in stack of task %s/%d at offset %lu in frame:\n",

	       addr, current->comm, task_pid_nr(current), offset);