From nobody Wed Apr 8 11:53:42 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F94DC32792 for ; Sun, 21 Aug 2022 00:08:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233029AbiHUAIo (ORCPT ); Sat, 20 Aug 2022 20:08:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235575AbiHUAId (ORCPT ); Sat, 20 Aug 2022 20:08:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39C1911477 for ; Sat, 20 Aug 2022 17:08:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 890E560C57 for ; Sun, 21 Aug 2022 00:08:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7993C433D7; Sun, 21 Aug 2022 00:08:29 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1oPYWC-005Djt-29; Sat, 20 Aug 2022 20:08:44 -0400 Message-ID: <20220821000844.510643400@goodmis.org> User-Agent: quilt/0.66 Date: Sat, 20 Aug 2022 20:07:38 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Christoph Hellwig , Rasmus Villemoes , Luc Van Oostenryck , Linus Torvalds , Jens Axboe , Bart Van Assche Subject: [for-linus][PATCH 01/10] tracing: Suppress sparse warnings triggered by is_signed_type() References: <20220821000737.328590235@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Bart Van Assche Using a __bitwise type in a tracing __field() definition triggers four sparse warnings in stage 4 of expanding the TRACE_EVENT() macro. These warnings are triggered by the is_signed_type() macro implementation. Since there is no known way of checking signedness of a bitwise type without triggering sparse warnings, disable signedness checking when verifying code with sparse. Note: work is in progress to improve sparse but has not yet landed. See also "[PATCH 0/5] allow -1 and compares in bitwise types" (https://lore.kernel.org/all/20220627190540.13358-1-luc.vanoostenryck@gmail= .com/ ). Link: https://lore.kernel.org/linux-trace-devel/20220717151047.19220-1-bvan= assche@acm.org Suggested-by: Christoph Hellwig Cc: Rasmus Villemoes Cc: Luc Van Oostenryck Cc: Linus Torvalds Cc: Jens Axboe Signed-off-by: Bart Van Assche Signed-off-by: Steven Rostedt (Google) Acked-by: Kees Cook --- include/linux/trace_events.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index b18759a673c6..b60347a0ccde 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -814,7 +814,19 @@ extern int trace_add_event_call(struct trace_event_cal= l *call); extern int trace_remove_event_call(struct trace_event_call *call); extern int trace_event_get_offsets(struct trace_event_call *call); =20 +/* + * There is no known way to check signedness of __bitwise types without + * triggering a sparse warning. Hence the #ifdef __CHECKER__. + * + * Since there is another definition of is_signed_type() in , + * undefine is_signed_type() before redefining it. + */ +#undef is_signed_type +#ifdef __CHECKER__ +#define is_signed_type(type) 0 +#else #define is_signed_type(type) (((type)(-1)) < (type)1) +#endif =20 int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set); int trace_set_clr_event(const char *system, const char *event, int set); --=20 2.35.1