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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 24B2BC04AB6 for ; Tue, 28 May 2019 17:20:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC0F92075B for ; Tue, 28 May 2019 17:20:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="1Supj4ah" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727035AbfE1RUD (ORCPT ); Tue, 28 May 2019 13:20:03 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52878 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbfE1RUC (ORCPT ); Tue, 28 May 2019 13:20:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=qsxG6nrZHIG6W3Utol1ADoMvGd1Fu++xoBrnNWF+g6w=; b=1Supj4ahiukX6UPbvHZyF03YR JO7bTjVrRlpg3pXBYsQwJVeAlQKNYjDNcrxz6LxCL3NRIKiPGHN86GcNMarsgpOe/yDDBOX+qd9HX t0eDk7tmUTTGVo4y4ZvvSj8c6dogbCtG2WZleFI/klu1NQNWDS816bL2y3mQre1xbSbEaWoDlWP4H yW47YPj0WIH/Cd4jIA4hLnLjXOmbAglKlOPTM0RRRilh+UWVC6ci3C6Dsu0qMsAqe0uJ7nDyOEsxO QfA362ClWXh1pOCLsldHPuSlnzWnbtzrTpe5ei0+3SKvxsnQfR4EVUrpMJnrLgHwFrsoJ8juDVKfd guKqq55Eg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hVflI-0005pf-Tr; Tue, 28 May 2019 17:19:45 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4AAD52007CDEA; Tue, 28 May 2019 19:19:42 +0200 (CEST) Date: Tue, 28 May 2019 19:19:42 +0200 From: Peter Zijlstra To: Marco Elver Cc: aryabinin@virtuozzo.com, dvyukov@google.com, glider@google.com, andreyknvl@google.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, x86@kernel.org, arnd@arndb.de, jpoimboe@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, kasan-dev@googlegroups.com Subject: Re: [PATCH 2/3] tools/objtool: add kasan_check_* to uaccess whitelist Message-ID: <20190528171942.GV2623@hirez.programming.kicks-ass.net> References: <20190528163258.260144-1-elver@google.com> <20190528163258.260144-2-elver@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190528163258.260144-2-elver@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 28, 2019 at 06:32:57PM +0200, Marco Elver wrote: > This is a pre-requisite for enabling bitops instrumentation. Some bitops > may safely be used with instrumentation in uaccess regions. > > For example, on x86, `test_bit` is used to test a CPU-feature in a > uaccess region: arch/x86/ia32/ia32_signal.c:361 That one can easily be moved out of the uaccess region. Any else? > Signed-off-by: Marco Elver > --- > tools/objtool/check.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/tools/objtool/check.c b/tools/objtool/check.c > index 172f99195726..eff0e5209402 100644 > --- a/tools/objtool/check.c > +++ b/tools/objtool/check.c > @@ -443,6 +443,8 @@ static void add_ignores(struct objtool_file *file) > static const char *uaccess_safe_builtin[] = { > /* KASAN */ > "kasan_report", > + "kasan_check_read", > + "kasan_check_write", > "check_memory_region", > /* KASAN out-of-line */ > "__asan_loadN_noabort", > -- > 2.22.0.rc1.257.g3120a18244-goog >