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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS 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 2EABBC10F0E for ; Fri, 12 Apr 2019 15:33:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEEE42171F for ; Fri, 12 Apr 2019 15:33:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555083181; bh=WzX8XGkOY041LE4RUQ/RFMWNbG+GGbzcioro+MbFIBg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=mK1r/izYnumvNNiu+8z0XTat+K+/iN7iKMPJ0phVGuknV/zIkj8MMMVXIwKtCdkl0 INv+UQXyXIbfFRTKcQmSYnI2wI6AVKLQwDUBtiiVel85rIKBmbd0x9sjkdHa6YwW3V hBshRTOFpaMb2opXHOoM6gW7iAU8DhhkPATfCj/k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727104AbfDLPc7 (ORCPT ); Fri, 12 Apr 2019 11:32:59 -0400 Received: from mail-lf1-f49.google.com ([209.85.167.49]:32978 "EHLO mail-lf1-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726963AbfDLPc7 (ORCPT ); Fri, 12 Apr 2019 11:32:59 -0400 Received: by mail-lf1-f49.google.com with SMTP id j11so7842798lfm.0 for ; Fri, 12 Apr 2019 08:32:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=NXbKfjDtbjJTyw5Ef0Kix1bfyNOyzTYwEKpGgqOg0TQ=; b=b29dvSdD9cfYHQabi8DqTd65SPCA4obhIln3RU66IajZ136WcOn3NOWVgBFDYVDptF Pp2/5FS6XX6lmgEFeW+6w+62lN8PLub/YTGNvXWjkP9nQCUx99g1ArdD+fsyH0+QY+kM Dy3/6RufoCQqG8kSbDLFyrVvMcECFbfR4KUgE= 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=NXbKfjDtbjJTyw5Ef0Kix1bfyNOyzTYwEKpGgqOg0TQ=; b=XYxI670BljsxMIgawK0srciRvoJOB+nHDbWu9kV+15IqVgv+3ZYafvJAUeZBrpgCYt bG65bEDrp/7qiJLsRYHj6zaq097cUj8RkYbmceWSCcZll4AXal+gcdjBD5XyU+RIVICp atf8kPyk9wWRREIFYZpv5cJHmSmgu3O5zitOhJT+j+SeAPannovbAdzO9GaAHqzjcrpV UCJBqPlMPRhKTbgBP9QwuELthGeb1KtIrjayV4jLJJWY7xKRmFqtd75CD/78GhMof9lZ Pg/AUTdMoOxAFWz9zvqZczWh5c6TADq43LEvrQ9O/NQqqtnd7eGzqU134Q+tKrED7gRs vYeg== X-Gm-Message-State: APjAAAVjw9ZDNjZ+aAY/kJmBZr8Oxm+pm3Dk0J332cEB/IdDZCIrV0PL 1acaAJK2sur3XszNdnPnwgIpGKWliqc= X-Google-Smtp-Source: APXvYqyKKxlM4QaekPYCFKiOvdMUkzmUPtETBIVyQaKqZsp5KyPoZZuwcMvgb3TnQcqHY25ywqvPVQ== X-Received: by 2002:ac2:518b:: with SMTP id u11mr14094492lfi.46.1555083176265; Fri, 12 Apr 2019 08:32:56 -0700 (PDT) Received: from mail-lj1-f171.google.com (mail-lj1-f171.google.com. [209.85.208.171]) by smtp.gmail.com with ESMTPSA id n9sm7896773lfl.35.2019.04.12.08.32.55 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 Apr 2019 08:32:55 -0700 (PDT) Received: by mail-lj1-f171.google.com with SMTP id h16so9228314ljg.11 for ; Fri, 12 Apr 2019 08:32:55 -0700 (PDT) X-Received: by 2002:a2e:9a91:: with SMTP id p17mr30639609lji.127.1555083174727; Fri, 12 Apr 2019 08:32:54 -0700 (PDT) MIME-Version: 1.0 References: <5cae03c4.iIPk2cWlfmzP0Zgy%lkp@intel.com> <20190411193906.GA12232@hirez.programming.kicks-ass.net> <20190411195424.GL14281@hirez.programming.kicks-ass.net> <20190411211348.GA8451@worktop.programming.kicks-ass.net> <20190412105633.GM14281@hirez.programming.kicks-ass.net> In-Reply-To: <20190412105633.GM14281@hirez.programming.kicks-ass.net> From: Linus Torvalds Date: Fri, 12 Apr 2019 08:32:38 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: 1808d65b55 ("asm-generic/tlb: Remove arch_tlb*_mmu()"): BUG: KASAN: stack-out-of-bounds in __change_page_attr_set_clr To: Peter Zijlstra Cc: kernel test robot , LKP , Linux List Kernel Mailing , Linux-MM , linux-arch , Ingo Molnar , Thomas Gleixner , Will Deacon , Andy Lutomirski , Nadav Amit , Linus Torvalds 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, Apr 12, 2019 at 3:56 AM Peter Zijlstra wrote: > > --- a/arch/x86/mm/tlb.c > +++ b/arch/x86/mm/tlb.c > @@ -728,7 +728,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, > { > int cpu; > > - struct flush_tlb_info info __aligned(SMP_CACHE_BYTES) = { > + struct flush_tlb_info info = { > .mm = mm, > .stride_shift = stride_shift, > .freed_tables = freed_tables, > Ack. We should never have stack alignment bigger than 16 bytes. And preferably not even that. Trying to align stack at a cacheline boundary is wrong - if you *really* need things to be that aligned, do something else (regular kmalloc, percpu temp area, static allocation - whatever). Linus