From patchwork Mon Aug 24 08:29:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 264981 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 4D097C433E3 for ; Mon, 24 Aug 2020 09:49:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 209BD2071E for ; Mon, 24 Aug 2020 09:49:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598262571; bh=X1Jc6HRrlX3sT+03uEUsKl4ouu4xw5betJQxvtle9D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HEJCNhjxDe6uSto3ogCAAMqgPoe29HRva+iX+KdSS9zOn0Oj3NxvyOJi6CfcQ/2Rn IGrB3h4FjqXP5IXcb/Rane8Unk1KU2DNkRMU+I3xbL8FfYKSdjmlqZL2K5zRWM6AIg S32j3ZU8ljpFV8j6YIll7sIgcfwHwwnoqnlZkAVk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728660AbgHXIjq (ORCPT ); Mon, 24 Aug 2020 04:39:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:55834 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728670AbgHXIjm (ORCPT ); Mon, 24 Aug 2020 04:39:42 -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 336F82177B; Mon, 24 Aug 2020 08:39:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258381; bh=X1Jc6HRrlX3sT+03uEUsKl4ouu4xw5betJQxvtle9D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kkoLwT/zbNTDZDu1l7fIMLaJll9e8fCbHtRSwieePHADc9Xutfg6Jwq1vbp489/em ekC7ulkbyEdJZJsUlwAmFGVLC9rMh7ZqtKETBuuElyi5mz6Meb/g2u18ri4KInGMVF ekMvHjhXDQHdh4oU/bCCJKGA8mN+utM2BLUozSeY= 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 5.7 027/124] drm/amd/display: fix pow() crashing when given base 0 Date: Mon, 24 Aug 2020 10:29:21 +0200 Message-Id: <20200824082410.747521526@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200824082409.368269240@linuxfoundation.org> References: <20200824082409.368269240@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 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),