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 91C51C4332F for ; Mon, 12 Dec 2022 10:38:00 +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:In-Reply-To:MIME-Version:References: 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=in5g59x5a5jywASBw7oto2ZJfEGvhJgUg3g41tGVK6Q=; b=EPU4T5PQOZgYMO 6Mc0M+e23ABLqkfPf2L5nwuhH26Q0jXZc6PUxwlduC6rGXfTn/V3P004E+4g91ELUP/hy1d9t5qzL 6/3g9L2go+6tuUkBhbz3LSREweKcBXuEIym0GCN7A1Wavv5SXaL+mnfxv6F/5g4Hb/S62R5Sc0f4C wFGtKjGnLYzuWQW0IAxrOr8xSH8Os5dZzne9BkQrwRYTZTO3x0oOM9f1DDjY+NTwdwPPa7CvgBNct hQL0oWv9JdsDWEWnw8eiWIiJizMioQlrwQiXU3Z/etlQCcz9Z4D9tdB8gzIrbw/+pvIED9n+BRAbX HXJkrWEDUaFOEtnH7P8A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p4gAw-00D5dx-K0; Mon, 12 Dec 2022 10:36:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p4gAj-00D4tt-Tv for linux-arm-kernel@lists.infradead.org; Mon, 12 Dec 2022 10:36:36 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 952741FB; Mon, 12 Dec 2022 02:37:08 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.40.60]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AC2723F5A1; Mon, 12 Dec 2022 02:36:26 -0800 (PST) Date: Mon, 12 Dec 2022 10:36:23 +0000 From: Mark Rutland To: Steven Rostedt 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: References: <20221209143402.3332369-1-ardb@kernel.org> <20221209165139.37d033ee@gandalf.local.home> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221209165139.37d033ee@gandalf.local.home> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221212_023634_053202_66BB4F28 X-CRM114-Status: GOOD ( 21.31 ) 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, Dec 09, 2022 at 04:51:39PM -0500, Steven Rostedt wrote: > 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") Ah; it's slightly more subtle since these were on different branches that got merged. Either's correct in its own branch, and the merge is where things went wrong. I think the overall least confusing thing is to bite the bullet and list both REGS and ARGS, i.e. depends on DYNAMIC_FTRACE_WITH_ARGS || DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER ... and for the fixes tag have: Fixes: ddc9863e9e90 ("scs: Disable when function graph tracing is enabled") That way the commit is correct regardless of the REGS -> ARGS conversion, and will work if backported independently. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel