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=-10.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 D6D91C433E1 for ; Mon, 24 Aug 2020 09:59:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1A8720639 for ; Mon, 24 Aug 2020 09:59:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598263156; bh=X1Jc6HRrlX3sT+03uEUsKl4ouu4xw5betJQxvtle9D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=w3pYtW0+MtbX4LB9soZOIqMS00CZBL4MYve2iGWED+ZfOrDGD3C6RSgXoc7osaqag VpUW2B/+1exrJm+qY0MegiAPvN+S5DT7ALx6rfv/2v+bb1+53NbUJWI4JrOfr5FqwF ch8l4r3yzJ+/8Tq+MELYumOnbCWf4Rs4NLk556Iw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727079AbgHXIdh (ORCPT ); Mon, 24 Aug 2020 04:33:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:41272 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727073AbgHXIdg (ORCPT ); Mon, 24 Aug 2020 04:33:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5179D206F0; Mon, 24 Aug 2020 08:33:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258015; bh=X1Jc6HRrlX3sT+03uEUsKl4ouu4xw5betJQxvtle9D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pttGgOa3iucOAFVdGMpboDoH+KaVLCNOgIiLOXIb8veBcoQXGZelx/iOmYpdmRqGq 4pPHHd19NMlQvI4GpPigeTppDb7OeecirOYA2WQ1maOsETtwuP5uTvu6qBQoa3J1FM /Fj0n6zVlpicPCMViaeUayoRuXbxxNy71/m4+cyg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Krunoslav Kovac , Anthony Koo , Rodrigo Siqueira , Alex Deucher Subject: [PATCH 5.8 042/148] drm/amd/display: fix pow() crashing when given base 0 Date: Mon, 24 Aug 2020 10:29:00 +0200 Message-Id: <20200824082416.069469455@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200824082413.900489417@linuxfoundation.org> References: <20200824082413.900489417@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Krunoslav Kovac commit d2e59d0ff4c44d1f6f8ed884a5bea7d1bb7fd98c upstream. [Why&How] pow(a,x) is implemented as exp(x*log(a)). log(0) will crash. So return 0^x = 0, unless x=0, convention seems to be 0^0 = 1. Cc: stable@vger.kernel.org Signed-off-by: Krunoslav Kovac Reviewed-by: Anthony Koo Acked-by: Rodrigo Siqueira Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/display/include/fixed31_32.h | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/amd/display/include/fixed31_32.h +++ b/drivers/gpu/drm/amd/display/include/fixed31_32.h @@ -431,6 +431,9 @@ struct fixed31_32 dc_fixpt_log(struct fi */ static inline struct fixed31_32 dc_fixpt_pow(struct fixed31_32 arg1, struct fixed31_32 arg2) { + if (arg1.value == 0) + return arg2.value == 0 ? dc_fixpt_one : dc_fixpt_zero; + return dc_fixpt_exp( dc_fixpt_mul( dc_fixpt_log(arg1),