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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 CE616C388F7 for ; Wed, 4 Nov 2020 09:05:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B5E022264 for ; Wed, 4 Nov 2020 09:05:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604480700; bh=RrG7UZ6WXi39gsCIBfUePqokH5ljjR4rAlO1FEu4eP4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=xU6s1Uo8saJ9u8657m5XEznfWd1RU8ULYxXzqMVR8l2eINRcX/IVBvqbZY0/NaTpr L7qyG6v099qR25eOEEi8u+dhd1R5kVmvskwcyQttyJ/JBIU8mKf/oEBKl/VXoOFNms JUdaetRc6ArEYvAblVujU59r26DOAUfqXvB/R4F8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728361AbgKDJE7 (ORCPT ); Wed, 4 Nov 2020 04:04:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:54510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726029AbgKDJE6 (ORCPT ); Wed, 4 Nov 2020 04:04:58 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4E2DD2220B; Wed, 4 Nov 2020 09:04:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604480698; bh=RrG7UZ6WXi39gsCIBfUePqokH5ljjR4rAlO1FEu4eP4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lgKqgbnMumChVGaGLx9OqXvrCL2umG5saMgHEwPOhTdPaaamkCnlRr3HiWvvkH0rP zAYPYAIP1yF0qcCcUlWinAdjXiZYhGHMTqcgujK8+jiJx31xKK78A57OeDfC/720ET NzUJR0KyrB+dp27OaaJ45prWzB8qFzXIxPERXvtM= Date: Wed, 4 Nov 2020 10:05:49 +0100 From: Greg Kroah-Hartman To: Michael Ellerman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Nicholas Piggin , Sasha Levin Subject: Re: [PATCH 4.19 056/191] powerpc: select ARCH_WANT_IRQS_OFF_ACTIVATE_MM Message-ID: <20201104090549.GB1588160@kroah.com> References: <20201103203232.656475008@linuxfoundation.org> <20201103203239.940977599@linuxfoundation.org> <87361qug5a.fsf@mpe.ellerman.id.au> <87zh3xude6.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87zh3xude6.fsf@mpe.ellerman.id.au> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Nov 04, 2020 at 12:19:45PM +1100, Michael Ellerman wrote: > Michael Ellerman writes: > > Greg Kroah-Hartman writes: > >> From: Nicholas Piggin > >> > >> [ Upstream commit 66acd46080bd9e5ad2be4b0eb1d498d5145d058e ] > >> > >> powerpc uses IPIs in some situations to switch a kernel thread away > >> from a lazy tlb mm, which is subject to the TLB flushing race > >> described in the changelog introducing ARCH_WANT_IRQS_OFF_ACTIVATE_MM. > >> > >> Signed-off-by: Nicholas Piggin > >> Signed-off-by: Michael Ellerman > >> Link: https://lore.kernel.org/r/20200914045219.3736466-3-npiggin@gmail.com > >> Signed-off-by: Sasha Levin > >> --- > >> arch/powerpc/Kconfig | 1 + > >> arch/powerpc/include/asm/mmu_context.h | 2 +- > >> 2 files changed, 2 insertions(+), 1 deletion(-) > >> > >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > >> index f38d153d25861..0bc53f0e37c0f 100644 > >> --- a/arch/powerpc/Kconfig > >> +++ b/arch/powerpc/Kconfig > >> @@ -152,6 +152,7 @@ config PPC > >> select ARCH_USE_BUILTIN_BSWAP > >> select ARCH_USE_CMPXCHG_LOCKREF if PPC64 > >> select ARCH_WANT_IPC_PARSE_VERSION > >> + select ARCH_WANT_IRQS_OFF_ACTIVATE_MM > > > > This depends on upstream commit: > > > > d53c3dfb23c4 ("mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race") > > > > > > Which I don't see in 4.19 stable, or in the email thread here. > > > > So this shouldn't be backported to 4.19 unless that commit is also > > backported. > > I just sent you a backport of d53c3dfb23c4 for 4.19. I've taken that at the proper part of this series now, thanks! greg k-h