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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8D6B8C4332F for ; Fri, 9 Dec 2022 21:52:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=imlefry23dSSm+SC9dyRSn5gJeGNx9Bij/8SqRd7ebU=; b=OnUoa2oo7dk06g P3VRWllzYgpX/tXspQLzxicMYtErLjrkCkdWK6S4FVH4r3R+/vFIhJrzi/tg8RBir4RqZEF96ViOE TXhuO5AS5657HTc7NI/SUss1np96cJwxHknoItcn1ZT6tgNsTDBkbazEoU59dTLRGwV6ruku6ZxrN loq6iGCDfQtslD1X+ZM4QO90DTPjhC43ceaQ6kKR51KpR4rKAICmyXif6pVe01GwVMQ1Xgc/PSeBP tbgCh6dL28TUlRH8qghzDlEk+A1Di6oPddlTSRZ6xScFLDweNP0TMEqJwkOBO1J1k5r23c9oAmjbd UWsZUKyGd/98u1dcc47A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p3lHZ-00BfHq-Am; Fri, 09 Dec 2022 21:51:49 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p3lHV-00BfHD-Rj for linux-arm-kernel@lists.infradead.org; Fri, 09 Dec 2022 21:51:47 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 65B40B828D6; Fri, 9 Dec 2022 21:51:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29DA3C433EF; Fri, 9 Dec 2022 21:51:42 +0000 (UTC) Date: Fri, 9 Dec 2022 16:51:39 -0500 From: Steven Rostedt To: Mark Rutland Cc: Ard Biesheuvel , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, will@kernel.org, samitolvanen@google.com, keescook@chromium.org, mhiramat@kernel.org Subject: Re: [PATCH] ftrace: Allow WITH_ARGS flavour of graph tracer with shadow call stack Message-ID: <20221209165139.37d033ee@gandalf.local.home> In-Reply-To: References: <20221209143402.3332369-1-ardb@kernel.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221209_135146_066255_E4B4A220 X-CRM114-Status: GOOD ( 20.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 9 Dec 2022 14:40:25 +0000 Mark Rutland wrote: > On Fri, Dec 09, 2022 at 03:34:02PM +0100, Ard Biesheuvel wrote: > > The recent switch on arm64 from DYNAMIC_FTRACE_WITH_REGS to > > DYNAMIC_FTRACE_WITH_ARGS failed to take into account that we currently > > require the former in order to allow the function graph tracer to be > > enabled in combination with shadow call stacks. This means that this is > > no longer permitted at all, in spite of the fact that either flavour of > > ftrace works perfectly fine in this combination. > > > > Given that arm64 is the only arch that implements shadow call stacks in > > the first place, let's update the condition to just reflect the arm64 > > change. When other architectures adopt shadow call stack support, this > > can be revisited if needed. > > > > Signed-off-by: Ard Biesheuvel > > My bad; sorry about this, and thanks for the fix! > > Acked-by: Mark Rutland > > We should probably also add: > > Fixes: 26299b3f6ba26bfc ("ftrace: arm64: move from REGS to ARGS") Actually, I believe it is: Fixes: ddc9863e9e90 ("scs: Disable when function graph tracing is enabled") As according to the comments, scs is broken with function graph unless function graph is using the ftrace mechanism. And that is only true if WITH_ARGS is set, not REGS. Acked-by: Steven Rostedt (Google) -- Steve _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel