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=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,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 A2FC7C10F13 for ; Tue, 16 Apr 2019 08:03:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E2F52073F for ; Tue, 16 Apr 2019 08:03:53 +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="KMLq8vBC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728587AbfDPIDw (ORCPT ); Tue, 16 Apr 2019 04:03:52 -0400 Received: from merlin.infradead.org ([205.233.59.134]:42050 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726890AbfDPIDv (ORCPT ); Tue, 16 Apr 2019 04:03:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version: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:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=TW8PGBx7kunZJN2Y1HJoHs2KrbhzullLyGfZjeeHZdA=; b=KMLq8vBC2cp3ng50OTZORdsI22 x6drZIuzUTj1OQU5IHmc12LWrtXTK7r1HVw3hEP8GVvsQeDyNn3dpVd9cxebIUDrmIsnras6G8cOX 63x52qmjEMsYFp3FhmJvDsDjVLOh4bqBrEavGkjL0M/GTVO2uPo0ziTR2c7Ebfxlpxih9Z1mSOdTX j/1paH1dKN28B1MG+up5Yur/5q3CaQWl4JrzrT1Ll2eHCRZIzzOVsWQ6mc5A4HNBJWWXu6qle7QE/ NH3Lkb3dBrR8axBjHCIxXBrSC6Qb5PcAD6/1gK36+MhC4aDFqwrJazZd5MHKmumEJSvDKs75k5uws uKIGYwzA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hGJ47-0000mC-9E; Tue, 16 Apr 2019 08:03:40 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id ED591981E5B; Tue, 16 Apr 2019 10:03:35 +0200 (CEST) Date: Tue, 16 Apr 2019 10:03:35 +0200 From: Peter Zijlstra To: Thomas Gleixner , Ingo Molnar , Borislav Petkov Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Andy Lutomirski , Nadav Amit , Dave Hansen Subject: [PATCH] x86/tlb: Revert: Align TLB invalidation info Message-ID: <20190416080335.GM7905@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 It was found that under some .config options (notably L1_CACHE_SHIFT=7) and compiler combinations this on-stack alignment leads to a 320 byte stack usage, which then triggers a KASAN stack warning elsewhere. Using 320 bytes of stack space for a 40 byte structure is ludicrous and clearly not right. Fixes: 515ab7c41306 ("x86/mm: Align TLB invalidation info") Signed-off-by: Peter Zijlstra (Intel) --- Index: linux-2.6/arch/x86/mm/tlb.c =================================================================== --- linux-2.6.orig/arch/x86/mm/tlb.c +++ linux-2.6/arch/x86/mm/tlb.c @@ -728,7 +728,7 @@ void flush_tlb_mm_range(struct mm_struct { 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,