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=-8.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,USER_IN_DEF_DKIM_WL 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 C10FCC43381 for ; Wed, 6 Mar 2019 15:01:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EBCF206DD for ; Wed, 6 Mar 2019 15:01:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="pBdpUgvA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728762AbfCFPBd (ORCPT ); Wed, 6 Mar 2019 10:01:33 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:52852 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727849AbfCFPBd (ORCPT ); Wed, 6 Mar 2019 10:01:33 -0500 Received: by mail-it1-f193.google.com with SMTP id g17so9907374ita.2 for ; Wed, 06 Mar 2019 07:01:32 -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; bh=ma7gN33rHEJBg2nn3xt0dVYNYTaKKiTjeqHcsyF0hbA=; b=pBdpUgvAvGvIVakxr0C+K5X4Gw/cSqF/AW50mdjmLdq3gT+W2tjbDMmfWX8JJy1udm OAMrdBYbBvuhVsWZRdTfVGYOn/VPj3lcSJiTfxOxE9u6rHF1uZKly1V2BKKrnvIG3rDF rwCf0xm6VUSV9xHz50xXEpHjrWOLZP+PDTKN1IF2u18w2ncLv2Q/x2qy6unu1G5jdC3m m4I+SCQAdS8voqnMN3AO9/9xin2lGJcSfJ7sAmLVOP5X+5g0U5KYbeulFHXbjeYSIfJU BLuaklxaezPJTzH8v8TsBSjUMVabQ3t0timSb621UrL8/wnfnxghedVLci27S9TD87HR LO9Q== 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; bh=ma7gN33rHEJBg2nn3xt0dVYNYTaKKiTjeqHcsyF0hbA=; b=kNO8mWrWQEmMkSvbP/O6zi+TGtScOAywE1WrFli9/2JDmS65a+h1LflbmPLUCwcN9+ 1L2W3mYK2aecIg5ZVTZjNWBvKxoKu3/yrRkdY7hSSpGrpIRXMRpLEalRT8gkNuSK9YCZ eoM3XRP7/onlR4V8fYKuAegp8UMigGGsR9ugZtQ0w4N0xHQPbgyy698i1hJ4F3Te1D4U lAVNpzOns8+I0uOAXMjWe1jJLFxek3q8DFH22gk1KZ80uAxvjlmUdEU8pjrOmysGBfh5 /KSbH03VjFraXzKbdOmwDbW6jMXltx6i8NoPTo2COSKcYgwh+R479S4XubF0x/qrSDIs kRSw== X-Gm-Message-State: APjAAAUIKnaA+CpUH9u/x0ozeU8MISs0bVPEId6yiiGqAikwutQJCKb1 hNattV6h90C/t8wArOEtFE1MgzH+HlkNV9XXvIMxcQ== X-Google-Smtp-Source: APXvYqzEazw1Mc+SDDFsHpyRBxuO1roRHBSKrbBBfer7mH9u/Oq15c1caHcTwZx9eb6wxlv/dUYFVXTwOa1NXX8hW68= X-Received: by 2002:a24:c8:: with SMTP id 191mr2095149ita.166.1551884491972; Wed, 06 Mar 2019 07:01:31 -0800 (PST) MIME-Version: 1.0 References: <20190301144556.GY32477@hirez.programming.kicks-ass.net> <20190301152305.GJ32494@hirez.programming.kicks-ass.net> <20190306131347.GX32534@hirez.programming.kicks-ass.net> <20190306135728.GV32477@hirez.programming.kicks-ass.net> <20190306141237.GW32477@hirez.programming.kicks-ass.net> <20190306143439.GY32534@hirez.programming.kicks-ass.net> <20190306145555.GX32477@hirez.programming.kicks-ass.net> In-Reply-To: <20190306145555.GX32477@hirez.programming.kicks-ass.net> From: Dmitry Vyukov Date: Wed, 6 Mar 2019 16:01:20 +0100 Message-ID: Subject: Re: [PATCH 1/8] kasan,x86: Frob kasan_report() in an exception To: Peter Zijlstra Cc: Linus Torvalds , Thomas Gleixner , "H. Peter Anvin" , Julien Thierry , Will Deacon , Andy Lutomirski , Ingo Molnar , Catalin Marinas , James Morse , valentin.schneider@arm.com, Brian Gerst , Josh Poimboeuf , Andy Lutomirski , Borislav Petkov , Denys Vlasenko , LKML , Andrey Ryabinin Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 6, 2019 at 3:56 PM Peter Zijlstra wrote: > > On Wed, Mar 06, 2019 at 03:40:51PM +0100, Dmitry Vyukov wrote: > > On Wed, Mar 6, 2019 at 3:34 PM Peter Zijlstra wrote: > > > > mm/kasan/generic_report.o: warning: objtool: __asan_report_load1_noabort()+0x0: call to __fentry__() with UACCESS enabled > > > But if it makes things simpler for the objtool, then I think we can > > disable function tracer for generic_report.c too. > > It's not simpler; it is actually a correctness issue. Those functions > must not call into the tracer with AC=1 You are right! I assumed they are defined in kasan.c and then call into a report function that is compiled with -pg. We can either disable -pg for report.c, or move these callbacks into kasan.c which already has -pg disabled. I don't have strong preference either way as long as the option works in all cases.