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 37C6EC77B7C for ; Mon, 1 May 2023 23:11:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229889AbjEAXLJ (ORCPT ); Mon, 1 May 2023 19:11:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229810AbjEAXLJ (ORCPT ); Mon, 1 May 2023 19:11:09 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA4B31708 for ; Mon, 1 May 2023 16:11:07 -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 81E99617A8 for ; Mon, 1 May 2023 23:11:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A966C433D2; Mon, 1 May 2023 23:11:05 +0000 (UTC) Date: Mon, 1 May 2023 19:11:04 -0400 From: Steven Rostedt To: Indu Bhagat Cc: linux-toolchains@vger.kernel.org, daandemeyer@meta.com, andrii@kernel.org, kris.van.hees@oracle.com, elena.zannoni@oracle.com, nick.alcock@oracle.com Subject: Re: [POC 5/5] x86_64: invoke SFrame based stack tracer for user space Message-ID: <20230501191104.3f7baf03@gandalf.local.home> In-Reply-To: <20230501200410.3973453-6-indu.bhagat@oracle.com> References: <20230501200410.3973453-1-indu.bhagat@oracle.com> <20230501200410.3973453-6-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 Mon, 1 May 2023 13:04:10 -0700 Indu Bhagat wrote: > void > perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) > { > struct stack_frame frame; > const struct stack_frame __user *fp; > + bool sframe_avail; > > if (perf_guest_state()) { > /* TODO: We don't support guest os callchain now */ > @@ -2887,7 +2930,15 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs > if (perf_callchain_user32(regs, entry)) > return; > > + sframe_avail = check_sframe_state_p (current); > + > pagefault_disable(); > + > + if (sframe_avail && !sframe_callchain_user (current,1 entry, regs)) { > + pagefault_enable(); > + return; > + } > + So my idea is to have a more generic approach for user space stack traces that perf calls into, instead of having sframe hooking into perf. -- Steve