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 X-Spam-Level: X-Spam-Status: No, score=-1.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E6B7C4360F for ; Thu, 21 Feb 2019 15:58:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 338962084D for ; Thu, 21 Feb 2019 15:58:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550764698; bh=jnfblnvzpcOe8w+JDNqPpjNAwy9zczrur4oLKML/PzE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=mytByzDwO5PKoOC4/TUMBxOW3pEOkd/nH721yNgd2DOxWSPbfukAWe845iinjmbSu qWN4BXGh+6xmDMt+Z1vIfuaWVKDw74EovWZD3XfdrFgMijfU1uGgAOhFAOjK7K5KhL MN5f9Vv2Tpg2N7mHdbyKaSYUCPrmVh2uLWeFaunI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728422AbfBUP6Q (ORCPT ); Thu, 21 Feb 2019 10:58:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:51002 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725870AbfBUP6Q (ORCPT ); Thu, 21 Feb 2019 10:58:16 -0500 Received: from devbox (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 A9C902083E; Thu, 21 Feb 2019 15:58:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550764695; bh=jnfblnvzpcOe8w+JDNqPpjNAwy9zczrur4oLKML/PzE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lB/UEbzdYv7UjQdMXTesjehHmr4YKHz12hmAGSLVY+t8aHjm6WbrMaPGBPLFFbK8p FJAaoN+tyquS5G7jPZ93qf0DDuGPAFGygmgRUPeX4tpgGOPgYjqkUhi1K72wRFEXI6 c0/0GZowHESpxUTaG/kQdPBGbJaei0ggmtNqPSHk= Date: Fri, 22 Feb 2019 00:58:12 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Ingo Molnar , Andrew Morton , stable@vger.kernel.org, Changbin Du Subject: Re: [PATCH 1/2 v2] kprobe: Do not use uaccess functions to access kernel memory that can fault Message-Id: <20190222005812.04c5940c693b14cfdbe6ede7@kernel.org> In-Reply-To: <20190221093625.56afccd2@gandalf.local.home> References: <20190215174712.372898450@goodmis.org> <20190215174945.557218316@goodmis.org> <20190221165252.4a9033b3348f30f9d973dbc4@kernel.org> <20190221093625.56afccd2@gandalf.local.home> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-redhat-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 Thu, 21 Feb 2019 09:36:25 -0500 Steven Rostedt wrote: > On Thu, 21 Feb 2019 16:52:52 +0900 > Masami Hiramatsu wrote: > > > Basically OK to me. > > Could you use probe_kernel_read() in this context, since probe_mem_read() is a > > wrapper function for template code. > > > > With that change, > > > > Acked-by: Masami Hiramatsu > > This already hit Linus's tree. I was able to reproduce the crash, so I > streamlined it. I should have still pushed more for your ack first. > Sorry about that. Oh, never mind. That seems urgent issue for kprobe event. Thank you very much for fixing it! > For some reason, I thought the change was in the generic probe code, > and accepted the probe_mem_read(). Anyway, did you want to send a patch > to change it to probe_kernel_read(), for the merge window? No problem. > > And for the long term, I need to find more efficient (or smarter) way to do it, > > like strnlen_user() does. > > Agreed. Thank you, -- Masami Hiramatsu