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=-14.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 7A900C7618F for ; Fri, 19 Jul 2019 20:56:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48DC021849 for ; Fri, 19 Jul 2019 20:56:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wTxXBCRS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731772AbfGSU4j (ORCPT ); Fri, 19 Jul 2019 16:56:39 -0400 Received: from mail-pg1-f171.google.com ([209.85.215.171]:40986 "EHLO mail-pg1-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728148AbfGSU4j (ORCPT ); Fri, 19 Jul 2019 16:56:39 -0400 Received: by mail-pg1-f171.google.com with SMTP id x15so4620811pgg.8 for ; Fri, 19 Jul 2019 13:56:39 -0700 (PDT) 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=3NYv6TCWtb7tkR1P/MbWMgyIgT3S1PINtDcy9WMCXyk=; b=wTxXBCRSeppmWSR7yZ/z0fatUN5RT4CIrq5NGo/JoipBYdHByrus46FERdKzLm/Say sZq1nShQJtykJcyndXzxDXtIVSfFG2V5dvtIQ+wVGU0azw/IoP8kc6e11c1Ub8Wp5SO0 BVKoDVWLmTdXKj6ArxpIpfDs+c0NcAdOo3fyjCOp3z0e0CyCPa1HsqK6jBsfD04xjvyO D2JcnFOYZ+Mj3O1c133nZecyNSNGuMldvj0xUo5IA0m7qyELJYsdwzeX5ZYk8UKrYXiS fBUWIjysf/rtZRZAQ/vIPkmssohq9s2WEJAYUpa61wxBqSZzRQp7GZ1lAKEm3xNHDLxt sd6g== 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=3NYv6TCWtb7tkR1P/MbWMgyIgT3S1PINtDcy9WMCXyk=; b=Lb7bVcJidwEDkNwDqgQ3FNw6PzIyczW8uTtxwasohwvQpsH6SU09rFXtQ8cu7r2pfh aXtfPpMZGneOVJN0frtKLLQhxp1FELzqPL1B3Je2e2+x6n0OAQdiJvEQpMPQoWTA1qpo SDr0bd5vh/UeX1ufofIPa0pUle3flASsf1EF7RuNu792zq0fa+nIBSI+bK4NQOzsgZft n2KwzMPl9FzE68+/Vx/kk3MdvsRYwjdNA+nWMR7Xfqdd5H9BhnawmAPkM6qqSjYxE/dk TsurBsHCmKZ2E+TQC7cwZDSb6UtxQm2sRni7nLIL0gk1B+6lvGCeWPnncEAFd2X0hYhc 3Tlg== X-Gm-Message-State: APjAAAVSeaknnwGrTD+ZKVa6SEXuhpmDydGoB2ld/hb7Xv04Q/Lxvfug vYh7o3l760ThnDBdntMJ41tl18pzzZns/eTVFmWdmA== X-Google-Smtp-Source: APXvYqyMOIrfjIgnGwgMocYcJ0JN38hJDAsNgaSllqcJ5GyMRnAOgoT2e/hbgQDpittbt0zFbvtqobrf5jz1JuEtHFw= X-Received: by 2002:a63:60a:: with SMTP id 10mr25172182pgg.381.1563569798307; Fri, 19 Jul 2019 13:56:38 -0700 (PDT) MIME-Version: 1.0 References: <20190719200347.2596375-1-arnd@arndb.de> In-Reply-To: <20190719200347.2596375-1-arnd@arndb.de> From: Nick Desaulniers Date: Fri, 19 Jul 2019 13:56:27 -0700 Message-ID: Subject: Re: [PATCH] [v2] kasan: remove clang version check for KASAN_STACK To: Arnd Bergmann Cc: Andrew Morton , Qian Cai , Mark Brown , Andrey Konovalov , Andrey Ryabinin , Vasily Gorbik , LKML , clang-built-linux , Kostya Serebryany , Dmitry Vyukov , Alexander Potapenko 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 Fri, Jul 19, 2019 at 1:03 PM Arnd Bergmann wrote: > > asan-stack mode still uses dangerously large kernel stacks of > tens of kilobytes in some drivers, and it does not seem that anyone > is working on the clang bug. Acked-by: Nick Desaulniers > > Turn it off for all clang versions to prevent users from > accidentally enabling it once they update to clang-9, and > to help automated build testing with clang-9. > > Link: https://bugs.llvm.org/show_bug.cgi?id=38809 > Fixes: 6baec880d7a5 ("kasan: turn off asan-stack for clang-8 and earlier") > Signed-off-by: Arnd Bergmann > --- > v2: disable the feature for all clang versions, not just 9 and below. > --- > lib/Kconfig.kasan | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan > index 4fafba1a923b..7fa97a8b5717 100644 > --- a/lib/Kconfig.kasan > +++ b/lib/Kconfig.kasan > @@ -106,7 +106,6 @@ endchoice > > config KASAN_STACK_ENABLE > bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST > - default !(CLANG_VERSION < 90000) > depends on KASAN > help > The LLVM stack address sanitizer has a know problem that > @@ -115,11 +114,11 @@ config KASAN_STACK_ENABLE > Disabling asan-stack makes it safe to run kernels build > with clang-8 with KASAN enabled, though it loses some of > the functionality. > - This feature is always disabled when compile-testing with clang-8 > - or earlier to avoid cluttering the output in stack overflow > - warnings, but clang-8 users can still enable it for builds without > - CONFIG_COMPILE_TEST. On gcc and later clang versions it is > - assumed to always be safe to use and enabled by default. > + This feature is always disabled when compile-testing with clang > + to avoid cluttering the output in stack overflow warnings, > + but clang users can still enable it for builds without > + CONFIG_COMPILE_TEST. On gcc it is assumed to always be safe > + to use and enabled by default. > > config KASAN_STACK > int > -- > 2.20.0 > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20190719200347.2596375-1-arnd%40arndb.de. -- Thanks, ~Nick Desaulniers