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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 55C5AC10F14 for ; Thu, 3 Oct 2019 16:40:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29C8722466 for ; Thu, 3 Oct 2019 16:40:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570120849; bh=CKOJhoQWKwRHugdFdAlJKtgD9dw0sIWNrDvnzJWLrKE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=K+bA/m3zNBM94jnEmi3C2vqSr8F4v4acQCALDgaQPuGdsctT6lHnKHv+MgaT56QYC Zm4DNuCpoNErf7jgM71B+nF2PE68omExATaY+HUWC57b3X7cGqx35lkk/bnMUpLLkK stAfUMoEFP7aV4sFy3crK2pZGa4yxbQF0N7Uu34c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404957AbfJCQkr (ORCPT ); Thu, 3 Oct 2019 12:40:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:51038 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404950AbfJCQkr (ORCPT ); Thu, 3 Oct 2019 12:40:47 -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 CD0872070B; Thu, 3 Oct 2019 16:40:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570120846; bh=CKOJhoQWKwRHugdFdAlJKtgD9dw0sIWNrDvnzJWLrKE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UE2lttBddwxvIOCXE5IWG3P2TCZLNX83wUpwqg6RcGK3jdyOhcUj04JZQ3KDSqQy6 26Mf9atrk+bD+ze+dFgJQyVSA8W4vphjdkZTu7mqWwUFZlF+yirNizdWOQbrdV2OnW 83oyucdbg8/VerRL1kOcIc8JTIBB5wFxKzRQ4fWs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Nick Desaulniers , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.3 058/344] media: vivid: work around high stack usage with clang Date: Thu, 3 Oct 2019 17:50:23 +0200 Message-Id: <20191003154545.857596867@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154540.062170222@linuxfoundation.org> References: <20191003154540.062170222@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: Arnd Bergmann [ Upstream commit 1a03f91c2c2419c3709c4554952c66695575e91c ] Building a KASAN-enabled kernel with clang ends up in a case where too much is inlined into vivid_thread_vid_cap() and the stack usage grows a lot, possibly when the register allocation fails to produce efficient code and spills a lot of temporaries to the stack. This uses more than twice the amount of stack than the sum of the individual functions when they are not inlined: drivers/media/platform/vivid/vivid-kthread-cap.c:766:12: error: stack frame size of 2208 bytes in function 'vivid_thread_vid_cap' [-Werror,-Wframe-larger-than=] Marking two of the key functions in here as 'noinline_for_stack' avoids the pathological case in clang without any apparent downside for gcc. Signed-off-by: Arnd Bergmann Acked-by: Nick Desaulniers Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/platform/vivid/vivid-kthread-cap.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/media/platform/vivid/vivid-kthread-cap.c b/drivers/media/platform/vivid/vivid-kthread-cap.c index ed466d737a90d..003319d7816d7 100644 --- a/drivers/media/platform/vivid/vivid-kthread-cap.c +++ b/drivers/media/platform/vivid/vivid-kthread-cap.c @@ -232,8 +232,8 @@ static void *plane_vaddr(struct tpg_data *tpg, struct vivid_buffer *buf, return vbuf; } -static int vivid_copy_buffer(struct vivid_dev *dev, unsigned p, u8 *vcapbuf, - struct vivid_buffer *vid_cap_buf) +static noinline_for_stack int vivid_copy_buffer(struct vivid_dev *dev, unsigned p, + u8 *vcapbuf, struct vivid_buffer *vid_cap_buf) { bool blank = dev->must_blank[vid_cap_buf->vb.vb2_buf.index]; struct tpg_data *tpg = &dev->tpg; @@ -672,7 +672,8 @@ static void vivid_cap_update_frame_period(struct vivid_dev *dev) dev->cap_frame_period = f_period; } -static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs) +static noinline_for_stack void vivid_thread_vid_cap_tick(struct vivid_dev *dev, + int dropped_bufs) { struct vivid_buffer *vid_cap_buf = NULL; struct vivid_buffer *vbi_cap_buf = NULL; -- 2.20.1