kasan: improve stack frame info in reports

- Print at least task name and id for reports affecting allocas
   (get_address_stack_frame_info() does not support them).

 - Capitalize first letter of each sentence.

Link: https://lkml.kernel.org/r/aa613f097c12f7b75efb17f2618ae00480fb4bc3.1646237226.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan/report_generic.c

@@ -180,7 +180,7 @@ static void print_decoded_frame_descr(const char *frame_descr)
 		return;
 
 	pr_err("\n");
-	pr_err("this frame has %lu %s:\n", num_objects,
+	pr_err("This frame has %lu %s:\n", num_objects,
 	       num_objects == 1 ? "object" : "objects");
 
 	while (num_objects--) {
@@ -266,13 +266,14 @@ void kasan_print_address_stack_frame(const void *addr)
 	if (WARN_ON(!object_is_on_stack(addr)))
 		return;
 
+	pr_err("The buggy address belongs to stack of task %s/%d\n",
+	       current->comm, task_pid_nr(current));
+
 	if (!get_address_stack_frame_info(addr, &offset, &frame_descr,
 					  &frame_pc))
 		return;
 
-	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);
+	pr_err(" and is located at offset %lu in frame:\n", offset);
 	pr_err(" %pS\n", frame_pc);
 
 	if (!frame_descr)