livepatch/powerpc64: Add do_check_calltrace

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5CJ7X

--------------------------------

The calltrace check code is independent as do_check_calltrace,
for calltrace check of module.
No functional change.
Signed-off-by: NYang Jihong <yangjihong1@huawei.com>
Reviewed-by: NXu Kuohai <xukuohai@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/powerpc/kernel/livepatch_64.c

@@ -339,22 +339,12 @@ static void free_list(struct klp_func_list **funcs)
 	}
 }
 
-int klp_check_calltrace(struct klp_patch *patch, int enable)
+static int do_check_calltrace(struct walk_stackframe_args *args,
+			      int (*fn)(struct stackframe *, void *))
 {
 	struct task_struct *g, *t;
 	struct stackframe frame;
 	unsigned long *stack;
-	int ret = 0;
-	struct klp_func_list *check_funcs = NULL;
-	struct walk_stackframe_args args;
-
-	ret = klp_check_activeness_func(patch, enable, &check_funcs);
-	if (ret) {
-		pr_err("collect active functions failed, ret=%d\n", ret);
-		goto out;
-	}
-	args.check_funcs = check_funcs;
-	args.ret = 0;
 
 	for_each_process_thread(g, t) {
 		if (t == current) {
@@ -396,18 +386,36 @@ int klp_check_calltrace(struct klp_patch *patch, int enable)
 		frame.sp = (unsigned long)stack;
 		frame.pc = stack[STACK_FRAME_LR_SAVE];
 		frame.nip = 0;
-		if (check_funcs != NULL) {
-			klp_walk_stackframe(&frame, klp_check_jump_func, t, &args);
-			if (args.ret) {
-				ret = args.ret;
-				pr_debug("%s FAILED when %s\n", __func__,
-					 enable ? "enabling" : "disabling");
-				pr_info("PID: %d Comm: %.20s\n", t->pid, t->comm);
-				show_stack(t, NULL, KERN_INFO);
-				goto out;
-			}
+		klp_walk_stackframe(&frame, fn, t, args);
+		if (args->ret) {
+			pr_debug("%s FAILED when %s\n", __func__,
+				 args->enable ? "enabling" : "disabling");
+			pr_info("PID: %d Comm: %.20s\n", t->pid, t->comm);
+			show_stack(t, NULL, KERN_INFO);
+			return args->ret;
 		}
 	}
+	return 0;
+}
+
+int klp_check_calltrace(struct klp_patch *patch, int enable)
+{
+	int ret = 0;
+	struct klp_func_list *check_funcs = NULL;
+	struct walk_stackframe_args args;
+
+	ret = klp_check_activeness_func(patch, enable, &check_funcs);
+	if (ret) {
+		pr_err("collect active functions failed, ret=%d\n", ret);
+		goto out;
+	}
+	if (!check_funcs)
+		goto out;
+
+	args.check_funcs = check_funcs;
+	args.ret = 0;
+	args.enable = enable;
+	ret = do_check_calltrace(&args, klp_check_jump_func);
 
 out:
 	free_list(&check_funcs);