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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=no 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 A9691C432C3 for ; Tue, 19 Nov 2019 19:06:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 865BE22429 for ; Tue, 19 Nov 2019 19:06:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Z5T8NRw+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727329AbfKSTF7 (ORCPT ); Tue, 19 Nov 2019 14:05:59 -0500 Received: from mail-ot1-f65.google.com ([209.85.210.65]:41489 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727117AbfKSTF6 (ORCPT ); Tue, 19 Nov 2019 14:05:58 -0500 Received: by mail-ot1-f65.google.com with SMTP id 94so18875437oty.8 for ; Tue, 19 Nov 2019 11:05:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=0NatauBtPtJXOsbjFvuk9RBByg3dOvLiEzcuEjEIyik=; b=Z5T8NRw+0YDFCLzG1USKVrnQoi6akbzWg0AEZin9GQL7FupBZLWGa2T73NmchR7aSA pPfLQeAunLtuqxrSAXlTBx+JySV2avVYIQCmFaA05Dey3NogSQBBI4yygA7BCbP5/bpL Yz4o8QOp7wohXXlR2Faby+FBLa53lWNSYyaS7OaOdRc+bogOVA/MpJLVJaQtjBISre/G VJzG2KEDfV/FObm/rejuXbOc09Rlb98N5iCCm8csk+Bdw3QjvHpR0amM+IzfupcCN6LJ eRQqBM94k3KBJvq0hvkBY9LUx/UhTHhZXWIj+4eY3J7AO4aeEvK7IloE+ok2+yYUST7C /CuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=0NatauBtPtJXOsbjFvuk9RBByg3dOvLiEzcuEjEIyik=; b=mSrv48S++S6jd6Sw7E9tTbj8uHfu7GLcUhEnejKHB4A2KpZ/lnRSCSEj43Wu5TXOry +SOasxcok7e6d+2T1KaV1rR2cDE3iUefPAMOItDEg0kmSCsjSrQNrgG7PdZdneycYRQ4 TFk0qxRfMC2nM5mGoyb1h5c032rDSRGtLwGlG7L8ZPPVijjbOsDAvcLLAgbCeufe43Nr 9tOAS8DhaB6SKxWCSTCjwUIJtA3eIjwZzrlv8QY5oeZkH4pkVIw2Abxh8Q/EuDa/WiLt yIKwvs2D6JuPe0r/PAawg7yhe5fcjS4cOUjX7see8rBVUtP6b96dsVQYOhSBq3PtpbMb NUfg== X-Gm-Message-State: APjAAAWDb58xvGzmL7VH4j0DIQiJfgQvyp59ruWCtUvXPr9LtbVbW7mj U/EQu3r4BjXDtvhYSAVe9oru1v0Zjev2P3fviA1GWQ== X-Google-Smtp-Source: APXvYqyUZtQAxkb9wAVmkm9Ylw96P/rfxBE9DAOE0RfSEB3iGv1yRwmd6+Rz7VODo0gvsGqNKgLx2YPETkbUgURxTzg= X-Received: by 2002:a9d:69cf:: with SMTP id v15mr4680730oto.251.1574190357041; Tue, 19 Nov 2019 11:05:57 -0800 (PST) MIME-Version: 1.0 References: <20191119194658.39af50d0@canb.auug.org.au> <20191119183407.GA68739@google.com> <1574190168.9585.4.camel@lca.pw> In-Reply-To: <1574190168.9585.4.camel@lca.pw> From: Marco Elver Date: Tue, 19 Nov 2019 20:05:45 +0100 Message-ID: Subject: Re: linux-next: Tree for Nov 19 (kcsan) To: Qian Cai Cc: Randy Dunlap , Stephen Rothwell , Linux Next Mailing List , Linux Kernel Mailing List , kasan-dev , Dmitry Vyukov , "Paul E. McKenney" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 19 Nov 2019 at 20:02, Qian Cai wrote: > > On Tue, 2019-11-19 at 19:34 +0100, 'Marco Elver' via kasan-dev wrote: > > On Tue, 19 Nov 2019, Randy Dunlap wrote: > > > > > On 11/19/19 8:12 AM, Marco Elver wrote: > > > > On Tue, 19 Nov 2019 at 16:11, Randy Dunlap = wrote: > > > > > > > > > > On 11/19/19 12:46 AM, Stephen Rothwell wrote: > > > > > > Hi all, > > > > > > > > > > > > Changes since 20191118: > > > > > > > > > > > > > > > > on x86_64: > > > > > > > > > > It seems that this function can already be known by the compiler = as a > > > > > builtin: > > > > > > > > > > ../kernel/kcsan/core.c:619:6: warning: conflicting types for buil= t-in function =E2=80=98__tsan_func_exit=E2=80=99 [-Wbuiltin-declaration-mis= match] > > > > > void __tsan_func_exit(void) > > > > > ^~~~~~~~~~~~~~~~ > > > > > > > > > > > > > > > $ gcc --version > > > > > gcc (SUSE Linux) 7.4.1 20190905 [gcc-7-branch revision 275407] > > > > > > > > Interesting. Could you share the .config? So far I haven't been abl= e > > > > to reproduce. > > > > > > Sure, it's attached. > > > > Thanks, the config did the trick, even for gcc 9.0.0. > > > > The problem is CONFIG_UBSAN=3Dy. We haven't explicitly disallowed it li= ke > > with KASAN. In principle there should be nothing wrong with KCSAN+UBSAN= . > > > > There are 3 options: > > 1. Just disable UBSAN for KCSAN, and also disable KCSAN for UBSAN. > > 2. Restrict the config to not allow combining KCSAN and UBSAN. > > 3. Leave things as-is. > > > > Option 1 probably makes most sense, and I'll send a patch for that > > unless there are major objections. > > Both option #1 and #2 sounds quite unfortunate, as UBSAN is quite valuabl= e for > debugging. Hence, it is desire to make both work at the same time. Apologies, I think I was a bit unclear with #1. For #1, this just means that UBSAN is being disabled for the KCSAN runtime and vice-versa. All other parts of the kernel are still instrumented with both. See here: https://lore.kernel.org/linux-next/20191119185742.GB68739@google.= com/ Thanks, -- Marco