From mboxrd@z Thu Jan 1 00:00:00 1970 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 6ABB2C54EBD for ; Thu, 12 Jan 2023 09:49:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236635AbjALJth (ORCPT ); Thu, 12 Jan 2023 04:49:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239695AbjALJsF (ORCPT ); Thu, 12 Jan 2023 04:48:05 -0500 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A903050F74; Thu, 12 Jan 2023 01:44:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1673516654; x=1705052654; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=3kPZjp6HimM9YSIBTE/oXUSO1orPN/Jj19BPBdqSxnA=; b=l+UTFcoVie11piSJVRB6ILBprJamFId/vQFYo3nCzcJsU5EKzOHfmN89 FkmwIck/5/Sy1y/acUZiVCb/9gsqozH2cUX+DvBO/KW1euLKTH1RSAYIO eKEFAbO72xm5DnmtRiXot98JycuThn7QIqjBtehPF75CuULHFzUPzHINE gJEmoA3TQoEE8vEq05C1DYuOd5VphesIzECoK3FOEHiu/M6GbKJkH9cbn 7m92Eqkv5Se2pGOOnWjfN98gJ8W+6Xpl8ClrVGak7jA9R+ZublTQOUo1O VSuhZqK+lZexeRhUn+yHvFLMrkKfZDMt5xd5WXYNVe8eUcoAvFsE3l6EF g==; X-IronPort-AV: E=McAfee;i="6500,9779,10586"; a="307181255" X-IronPort-AV: E=Sophos;i="5.96,319,1665471600"; d="scan'208";a="307181255" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 01:42:58 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10586"; a="607725662" X-IronPort-AV: E=Sophos;i="5.96,319,1665471600"; d="scan'208";a="607725662" Received: from vbucoci-mobl1.ger.corp.intel.com ([10.252.52.43]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 01:42:55 -0800 Date: Thu, 12 Jan 2023 11:42:53 +0200 (EET) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: "Jiri Slaby (SUSE)" cc: gregkh@linuxfoundation.org, Kees Cook , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 07/11] tty: vt: replace BUG_ON() by WARN_ON_ONCE() In-Reply-To: <20230112080136.4929-7-jirislaby@kernel.org> Message-ID: <239b3d75-6186-3c3c-91bb-7ec46545f345@linux.intel.com> References: <20230112080136.4929-1-jirislaby@kernel.org> <20230112080136.4929-7-jirislaby@kernel.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-12161107-1673516577=:1665" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-12161107-1673516577=:1665 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 8BIT On Thu, 12 Jan 2023, Jiri Slaby (SUSE) wrote: > No need to panic in vc_uniscr_copy_line(), just warn. This should never > happen though, as vc_uniscr_check() is supposed to be called before > vc_uniscr_copy_line(). And the former checks vc->vc_uni_lines already. > > In any case, use _ONCE as vc_uniscr_copy_line() is called repeatedly for > each line. So don't flood the logs, just in case. > > Signed-off-by: Jiri Slaby (SUSE) > --- > drivers/tty/vt/vt.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c > index 119b3eafef59..db72375141b0 100644 > --- a/drivers/tty/vt/vt.c > +++ b/drivers/tty/vt/vt.c > @@ -535,7 +535,8 @@ void vc_uniscr_copy_line(const struct vc_data *vc, void *dest, bool viewed, > int offset = row * vc->vc_size_row + col * 2; > unsigned long pos; > > - BUG_ON(!uni_lines); > + if (WARN_ON_ONCE(!uni_lines)) > + return; > > pos = (unsigned long)screenpos(vc, offset, viewed); > if (pos >= vc->vc_origin && pos < vc->vc_scr_end) { > Reviewed-by: Ilpo Järvinen -- i. --8323329-12161107-1673516577=:1665--