From patchwork Mon Aug 24 08:30:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 265153 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=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 D79A1C433E1 for ; Mon, 24 Aug 2020 08:48:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACCE3208E4 for ; Mon, 24 Aug 2020 08:48:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258889; bh=X1Jc6HRrlX3sT+03uEUsKl4ouu4xw5betJQxvtle9D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=p/JEt4tSIBTdsXJAElS9RuXesvR8nX8InZ77QuYxsBvYwO1rOk2E7p6HM4kUjcJLt emigXn25H9qZWrBudSv4Jwp52mReG1/PSIxDq2K6h++VaW7wh0M/zGtu+1pyG6kcjS ANsg1C4Ychlf2tdPcWbu46FwaTU1DpiQHyTg8bek= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729523AbgHXIsC (ORCPT ); Mon, 24 Aug 2020 04:48:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:48608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729519AbgHXIsB (ORCPT ); Mon, 24 Aug 2020 04:48:01 -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 EBFDC204FD; Mon, 24 Aug 2020 08:48:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598258881; bh=X1Jc6HRrlX3sT+03uEUsKl4ouu4xw5betJQxvtle9D8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zag+ylPmsSNEizhhsHOtT1lnkWBlhWd/C2hTYxlg8aSE1MEjwj90wRgW/XeT8sK2i 6JSzd1rhhYdSr+zQcJ7iBPuwl7yEn0kYy42tDLmWtKewStnM7YmMzSFiyaAlxb4MU3 q8m/YnXRbhW0fpyohQcIlE7GdBq+NMQF3fk11NrE= 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 5.4 038/107] drm/amd/display: fix pow() crashing when given base 0 Date: Mon, 24 Aug 2020 10:30:04 +0200 Message-Id: <20200824082407.009645502@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200824082405.020301642@linuxfoundation.org> References: <20200824082405.020301642@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),