From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933678AbcKILg7 (ORCPT ); Wed, 9 Nov 2016 06:36:59 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:10220 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933377AbcKILg5 (ORCPT ); Wed, 9 Nov 2016 06:36:57 -0500 To: paulmck@linux.vnet.ibm.com, josh@joshtriplett.org Cc: rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org Subject: [srcu] Can we suppress sparse warning? From: Tetsuo Handa Message-Id: <201611092036.DAJ05243.HOOMQSVOJFFLtF@I-love.SAKURA.ne.jp> X-Mailer: Winbiff [Version 2.51 PL2] X-Accept-Language: ja,en,zh Date: Wed, 9 Nov 2016 20:36:31 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. When I build ---------- test/test.c ---------- #include static int __init test_init(void) { DEFINE_SRCU(srcu); int idx = srcu_read_lock(&srcu); void *ptr = srcu_dereference(ptr, &srcu); srcu_read_unlock(&srcu, idx); return -EINVAL; } module_init(test_init); MODULE_LICENSE("GPL"); ---------- test/test.c ---------- with C=1 option, I get test/test.c:7:21: error: incompatible types in comparison expression (different address spaces) warning from --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -605,7 +605,7 @@ static inline void rcu_preempt_sleep_check(void) /* Dependency order vs. p above. */ \ typeof(*p) *________p1 = (typeof(*p) *__force)lockless_dereference(p); \ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \ - rcu_dereference_sparse(p, space); \ + rcu_dereference_sparse(p, space); /** this line **/ \ ((typeof(*p) __force __kernel *)(________p1)); \ }) #define __rcu_dereference_protected(p, c, space) \ . I want to use srcu_dereference() at https://lists.01.org/pipermail/kbuild-all/2016-October/026587.html . Can we have srcu version of 995f1405610bd844 ("rcu: Suppress sparse warnings for rcu_dereference_raw()") ? Regards.