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=-17.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 C81C8C49EA4 for ; Wed, 23 Jun 2021 11:04:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5E059611C9 for ; Wed, 23 Jun 2021 11:04:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E059611C9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 027556B0011; Wed, 23 Jun 2021 07:04:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F19B46B0036; Wed, 23 Jun 2021 07:04:19 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DBA5E6B006C; Wed, 23 Jun 2021 07:04:19 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0108.hostedemail.com [216.40.44.108]) by kanga.kvack.org (Postfix) with ESMTP id A00306B0011 for ; Wed, 23 Jun 2021 07:04:19 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id CCAE9180B5F92 for ; Wed, 23 Jun 2021 11:04:19 +0000 (UTC) X-FDA: 78284704638.25.04A7639 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf06.hostedemail.com (Postfix) with ESMTP id 72B40C0201E1 for ; Wed, 23 Jun 2021 11:04:19 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 3E85E61003; Wed, 23 Jun 2021 11:04:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624446258; bh=SQLZ3jEqT4yhyhpj0Bb9UFclPy9A7MyuqA/xQ21E19o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nFel0oGOMMRKsUQpOzA8E0CCodJoyPdxcszRZjPwq2EF6srqWdV01nWToiHko05qr z4OoIBK2qzIUUUqLi/+1Gvaeq1z/zXhEREhS7P6V+BZdsMAMzIgeofMC0LMKzq5y+n 1csrxIqsmn/WulaMO7Mbf9WQjRdjHAJawSFsK2Y0e6dY6WVzN2K/wPJVVzwSvUO86F mW72uxO54TkbohQpB88ly/TTkjX7bt7ioUcsI+SbQ3wM1fv11Tz40VtNvJ94aR1DB1 OC7Rqt8S2FO3m8tUJGaII25RYFNWSq8XxR5rNaJ/nNUETYfy/n4Fvz8eabCU7nHi8c SIOV/J/fx2MjQ== Date: Wed, 23 Jun 2021 12:04:12 +0100 From: Will Deacon To: Zhenyu Ye Cc: Catalin Marinas , aneesh.kumar@linux.ibm.com, Marc Zyngier , steven.price@arm.com, Peter Zijlstra , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Xiexiangyou , liushixin2@huawei.com, huyaqin , zhurui3@huawei.com Subject: Re: [PATCH v1] arm64: tlb: fix the TTL value of tlb_get_level Message-ID: <20210623110412.GA32177@willie-the-truck> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 72B40C0201E1 Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=nFel0oGO; spf=pass (imf06.hostedemail.com: domain of will@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=will@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Stat-Signature: e9hdtr15idehqmz5n71ch1i1seqwzyzf X-HE-Tag: 1624446259-68409 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jun 23, 2021 at 03:05:22PM +0800, Zhenyu Ye wrote: > The TTL field indicates the level of page table walk holding the *leaf* > entry for the address being invalidated. But currently, the TTL field > may be set to an incorrent value in the following stack: > > pte_free_tlb > __pte_free_tlb > tlb_remove_table > tlb_table_invalidate > tlb_flush_mmu_tlbonly > tlb_flush > > In this case, we just want to flush a PTE page, but the tlb->cleared_pmds > is set and we get tlb_level = 2 in the tlb_get_level() function. This may > cause some unexpected problems. > > This patch set the TTL field to 0 if tlb->freed_tables is set. The > tlb->freed_tables indicates page table pages are freed, not the leaf > entry. > > Fixes: c4ab2cbc1d87 ("arm64: tlb: Set the TTL field in flush_tlb_range") > Reported-by: ZhuRui > Signed-off-by: Zhenyu Ye > --- > arch/arm64/include/asm/tlb.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h > index 61c97d3b58c7..c995d1f4594f 100644 > --- a/arch/arm64/include/asm/tlb.h > +++ b/arch/arm64/include/asm/tlb.h > @@ -28,6 +28,10 @@ static void tlb_flush(struct mmu_gather *tlb); > */ > static inline int tlb_get_level(struct mmu_gather *tlb) > { > + /* The TTL field is only valid for the leaf entry. */ > + if (tlb->freed_tables) > + return 0; > + > if (tlb->cleared_ptes && !(tlb->cleared_pmds || > tlb->cleared_puds || > tlb->cleared_p4ds)) Thanks. I can't see a better way around this, so I'll queue the patch. The stage-2 page-table code looks ok afaict, but please can you check it too? Cheers, Will