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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 678BCC4363A for ; Fri, 30 Oct 2020 10:32:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8CAC20704 for ; Fri, 30 Oct 2020 10:32:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hNjlIC5t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726318AbgJ3Kcx (ORCPT ); Fri, 30 Oct 2020 06:32:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726171AbgJ3Kcw (ORCPT ); Fri, 30 Oct 2020 06:32:52 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7987CC0613CF for ; Fri, 30 Oct 2020 03:32:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=kC/iXaDnkViO/EwRpn2Zres8ZBb6cXxROXB9UOEHSbs=; b=hNjlIC5tcT5H8d3IRZGvnYIri0 le5yP2DFrM+Fk3q01mXPY1O7RkVARmyeasyWb9MjOFAUjYLdxVdi9WQZihB9e+Ch9R8jK01qtX3Xn nBqXtHS88ToUbgOsjSuyraM9pTaTyX2UWZmXuYA14n7tGDYFreBiW2U8Ree64zBM9PKQXCE/HiPd/ E6gKRCtGkvhf0BJUcTx2HmCxBpa6rNY+TYs2DW7bR8fszuncD3kO4NxAv6tXFDVKhC2vVaDcz8i2w BGi9sYhXvITH2Gi9Vs9Ys1tkr7gAmlTwafEoqTc/8BKp8ypC9kMyelq/41t6xvzgszRlKbkXKtAG4 xEe0yR3A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kYRhl-0001Lw-DN; Fri, 30 Oct 2020 10:32:21 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 9C4A83012C3; Fri, 30 Oct 2020 11:32:20 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 521CA203F0EC3; Fri, 30 Oct 2020 11:32:20 +0100 (CET) Date: Fri, 30 Oct 2020 11:32:20 +0100 From: Peter Zijlstra To: Thomas Gleixner Cc: Steven Rostedt , LKML , Ingo Molnar , kan.liang@linux.intel.com, like.xu@linux.intel.com Subject: Re: [BUG] Stack overflow when running perf and function tracer Message-ID: <20201030103220.GH2611@hirez.programming.kicks-ass.net> References: <20201030002722.766a22df@oasis.local.home> <20201030090037.GZ2628@hirez.programming.kicks-ass.net> <877dr8nh6u.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <877dr8nh6u.fsf@nanos.tec.linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 30, 2020 at 11:26:01AM +0100, Thomas Gleixner wrote: > > The only thing I can come up with in a hurry is that that dummy_iregs > > thing really should be static. That's 168 bytes of stack out the window > > right there. > > What's worse is perf_sample_data which is 384 bytes and is 64 bytes aligned. Urgh, that thing just keeps on growing :/ I'll try and have a look if we can both shrink the thing and move it off stack.