Received: by 2002:ac0:98c7:0:0:0:0:0 with SMTP id g7-v6csp6040933imd; Wed, 31 Oct 2018 06:04:52 -0700 (PDT) X-Google-Smtp-Source: AJdET5cm24t8IuIo2ui9JtEGNTyZIMucndzNVJbhLUYOwrjI0Flrhq+vDDoS0MQFGGTjhPSYwTZh X-Received: by 2002:a62:3101:: with SMTP id x1-v6mr1019191pfx.204.1540991092498; Wed, 31 Oct 2018 06:04:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1540991092; cv=none; d=google.com; s=arc-20160816; b=nth4z4CFAkeIvz4+7QanCg92CpFd5mALf0CY9xr8L3J+TyELC3Jlwy0RHjsi6uLrFx GkQiJihr/m6Q5G9SkK4rSnY4YqyRpkS4YPnnDQwX+peB9nrRisFMWoxXKvaXUvPa3ZPr Vy73+lwXMq6WocVdcHPbZkMzWsmmz8JuZMYyon5yz2V3h6r3HhYqNSLUWFVAfFELqNe1 lAsyMbGyNbolDaSReGfWbaRx2e2U2KL7hhaCE+LikpPP74aBSawEXfF/4vXctYTepOYm nHmc3MtklgcHYeS2PAhsJcwC0abdnKepkXrcmBc8fwr4i0Gy/QaEeaTwJsCL6dV62OOb iAoA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=+GYUnUgrOkQnxvbOOzVtsDyXyRyFgJKZtoz+bLpG6Ro=; b=E3Ke8lMNZwVWxFcWEohEDwQ2xkyI0i1UvznLY99x5fkW4Y3hSLNYhWvhGb0mm7yJiJ 52ZXQDo8Jdbxw3KImDTFdFVlNrcdWBEGYneDUIOAVE+3EBjZYJkxF0182to8zn0T8NxA qGv+FhbktT3/6+yXP2S+aYCuDS1Y1PESbH2FB61wogPN5LwqmtTtatmkAceEREsK0YwS HN9/x7dKxXLfs8EeBm20k5aKONs7CIpFWjYb5FrNifrv0hYb2hv+97aFjEbOLb9dCrC5 qV2DyQt2svyImUB7uYxGuKDqmRdhvwpB8wJFz/6NmFiicXaaf6tXGcKfSZKbXqacDQ/F Y3kw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h13-v6si13633535pgj.457.2018.10.31.06.04.34; Wed, 31 Oct 2018 06:04:52 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729282AbeJaWBW (ORCPT + 99 others); Wed, 31 Oct 2018 18:01:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:39136 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729130AbeJaWBW (ORCPT ); Wed, 31 Oct 2018 18:01:22 -0400 Received: from vmware.local.home (unknown [217.16.13.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BAD7820664; Wed, 31 Oct 2018 13:03:22 +0000 (UTC) Date: Wed, 31 Oct 2018 09:03:17 -0400 From: Steven Rostedt To: Masami Hiramatsu Cc: Aleksa Sarai , "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Brendan Gregg , Christian Brauner , Aleksa Sarai , linux-kernel@vger.kernel.org Subject: Re: [PATCH] kretprobe: produce sane stack traces Message-ID: <20181031090317.4e211fdd@vmware.local.home> In-Reply-To: <20181030101206.2e5998ca3c75496c91ba5b09@kernel.org> References: <20181026132210.12569-1-cyphar@cyphar.com> <20181030101206.2e5998ca3c75496c91ba5b09@kernel.org> X-Mailer: Claws Mail 3.15.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Oct 2018 10:12:06 +0900 Masami Hiramatsu wrote: > Anyway, until that merge happens, this patch looks good to avoid > this issue for generic solution (e.g. for the arch which doesn't > supports retstack). I think its time to come up with an algorithm that makes function graph work with multiple users, and have kretprobes be able to hook into it just like kprobes hooks into function tracer. I have some ideas on how to get this done, and will try to have an RFC patch set ready by plumbers. -- Steve