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 X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3017EC04AAC for ; Mon, 6 May 2019 06:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 065C92082F for ; Mon, 6 May 2019 06:44:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725883AbfEFGn7 (ORCPT ); Mon, 6 May 2019 02:43:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48890 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725830AbfEFGn6 (ORCPT ); Mon, 6 May 2019 02:43:58 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C57DB3086226; Mon, 6 May 2019 06:43:58 +0000 (UTC) Received: from localhost (ovpn-204-123.brq.redhat.com [10.40.204.123]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6915560C44; Mon, 6 May 2019 06:43:58 +0000 (UTC) Date: Mon, 6 May 2019 08:43:57 +0200 From: Stanislaw Gruszka To: Tony Chuang Cc: "linux-wireless@vger.kernel.org" Subject: Re: [PATCH 5.1] rtw88: fix subscript above array bounds compiler warning Message-ID: <20190506064357.GB5115@redhat.com> References: <20190506062358.8288-1-sgruszka@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Mon, 06 May 2019 06:43:58 +0000 (UTC) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Mon, May 06, 2019 at 06:32:01AM +0000, Tony Chuang wrote: > > Subject: [PATCH 5.1] rtw88: fix subscript above array bounds compiler warning > > > > My compiler complains about: > > > > drivers/net/wireless/realtek/rtw88/phy.c: In function > > ‘rtw_phy_rf_power_2_rssi’: > > drivers/net/wireless/realtek/rtw88/phy.c:430:26: warning: array subscript is > > above array bounds [-Warray-bounds] > > linear = db_invert_table[i][j]; > > > > According to comment power_db should be in range 1 ~ 96 . > > To fix add check for boundaries before access the array. > > > > Signed-off-by: Stanislaw Gruszka > > --- > > RFC -> v1 > > - add check before accessing the array insted of > > rtw_phy_power_2_db() change. > > > > drivers/net/wireless/realtek/rtw88/phy.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/net/wireless/realtek/rtw88/phy.c > > b/drivers/net/wireless/realtek/rtw88/phy.c > > index 4381b360b5b5..9ca52a4d025a 100644 > > --- a/drivers/net/wireless/realtek/rtw88/phy.c > > +++ b/drivers/net/wireless/realtek/rtw88/phy.c > > @@ -423,6 +423,11 @@ static u64 rtw_phy_db_2_linear(u8 power_db) > > u8 i, j; > > u64 linear; > > > > + if (power_db > 96) > > + power_db = 96; > > + else if (power_db < 1) > > + power_db = 1; > > I think it's "return 1" here. Ehh, I missed that in your comment. However 'return 1' change the output of rtw_phy_db_2_linear() quite substantially as the smallest value (for power_db = 1) from db_invert_table[][] is 10. I'll post v2 patch, but please double check it's indeed correct logic. Thanks. Stanislaw