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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FF11C7EE2F for ; Fri, 26 May 2023 07:58:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242729AbjEZH6B (ORCPT ); Fri, 26 May 2023 03:58:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236721AbjEZH5p (ORCPT ); Fri, 26 May 2023 03:57:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C59A11999 for ; Fri, 26 May 2023 00:56:51 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id ED48164DE8 for ; Fri, 26 May 2023 07:56:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00A30C4339B; Fri, 26 May 2023 07:56:41 +0000 (UTC) Date: Fri, 26 May 2023 03:56:37 -0400 From: Steven Rostedt To: Indu Bhagat Cc: linux-toolchains@vger.kernel.org, peterz@infradead.org Subject: Re: [POC,V2 0/5] SFrame based stack tracer for user space in the kernel Message-ID: <20230526035637.26e333c4@rorschach.local.home> In-Reply-To: <20230526053215.3617580-1-indu.bhagat@oracle.com> References: <20230526053215.3617580-1-indu.bhagat@oracle.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-toolchains@vger.kernel.org On Thu, 25 May 2023 22:32:10 -0700 Indu Bhagat wrote: > Hello, Hi Indu, > > I have addressed the code review comments and hopefully made the SFrame > reader code more maintainable. > > Link to V1 posting: https://lore.kernel.org/linux-toolchains/20230501181515.098acdce@gandalf.local.home/T/#t This is great! > > The POC still suffers with the same issue: accessing SFrame data is not NMI > safe. This is expected to be addressed via the changes to perf workings > proposed by Steve. > > Once it is clearer what sort of callback APIs are required for the kernel to > gather user space stack trace using SFrame stack tracer, I am happy to work on > that later and make the necessary changes to SFrame stack tracer code in > lib/sframe/sframe_unwind.c and lib/sframe/sframe_state.c etc. Thanks for sending these. > > As some of the code in lib/sframe/iterate_phdr.[ch] will get dropped or > reworked, I skipped spending time on improving those files ATM. OK. -- Steve