From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A4117606A31D for ; Tue, 27 Oct 2026 19:25:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=4Ld4vpSv; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=mHRKmN4W DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=9KEB8qgzoIeFNOGcSLHLXb2uottvsKzkUwf/j7rEZPA=; b=4Ld4vpSvbibj18 fJYO6VcC/BkNJcPoT8p9T8Kp8Ba8sqWY+3yTADio2zSITEl042avqgvrUAHWEKJrXEDLnVksdw4Gd 9GMZbuk2ctw+qMudT2qTEf7ku7G+8ELI2Bs7uObT9Nb45s7SdczaFuoqT2sTQnEJU1vQCKfUENqeu oA83fwbem6S2NsQCL2Ri7xW5X3EziZth60w9SGc7wpq7vXc8AmplFm0e3c3UcjxGs6m23Q73xqHFI HZuXFpySSDXYi+DRhxIG7+4lP8+KECOL93LbbmTsNSu9u0ribpGVrpBMQoMi21pp7Qxrc4MqGME1U gwJJxHsHrByc3oVKVxYQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLmnl-00000005eBq-0Pfo; Tue, 27 Oct 2026 19:25:41 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLmnj-00000005eBg-1Lqn for kexec@lists.infradead.org; Tue, 27 Oct 2026 19:25:39 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 4F209601FA; Tue, 27 Oct 2026 19:25:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7550B1F01825; Tue, 27 Oct 2026 19:25:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793129138; bh=9KEB8qgzoIeFNOGcSLHLXb2uottvsKzkUwf/j7rEZPA=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=mHRKmN4WFGzQCMXXXAobAssayAt6MJNEX4XFML8kScSLR0RWj5iHQU4HOkyVdbrZ1 FAfkNQPNnukyYwievxpTrmJxM+E+k2Z82hK7ve6KZYqVtg7FqawBBiMhHOxJxjEa2p bYzJkytrLPqqJ7CYJwvxS2bJELBhxTcauV4K9skmwI9vhz22V6zo1hQGN2pFq2jDUl M7zoVMj2QRdGuUHWMrC7ZKykJhi9OVby5oo7z14LhbLEi2LRbLMRkqAZMODrWoiBbH 30E/CpCuG78KvyVtCKRteVs6ztPzOyHgprRt7kzAGfAfwY3zw6sGBJP1Q4vQ9OAjhg ELl7I7hL0bT0w== Message-ID: <2f436ecf-70fa-42f7-a0e2-8a27d179d1b2@kernel.org> Date: Tue, 27 Oct 2026 20:25:19 +0100 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 26/46] mm/mmu_gather: fix flushing ranges with 4 GiB or larger To: Dev Jain , Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Josef Bacik , stable@vger.kernel.org References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-26-6f74bec9a5bb@kernel.org> <21091d4e-0afb-4b5b-84ac-b36bac58e40f@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-7.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/27/26 08:35, Dev Jain wrote: > > > On 27/10/26 4:47 am, David Hildenbrand (Arm) wrote: >> From: Josef Bacik >> >> __tlb_adjust_range() takes the size of the range which has to be flushed >> as an unsigned int. Its callers, tlb_flush_{pte,pmd,pud,p4d}_range(), get >> and pass an unsigned long. Consequently, a range that is 4 GiB or larger >> gets truncated, possibly to 0. >> >> On arm64 with hugetlb, a 64k kernel can flush 16 GiB hugetlb PMDs, and a > > Nit: this wasn't obvious to me. Better expressed as: > "a 64K kernel can have 16 GiB hugepage mapped contiguously at the PMD level" > > >> 16k kernel can flush 64 GiB PUDs through tlb_unshare_pmd_ptdesc(). So >> at least these two scenarios are affected. >> >> Fix it by flushing the proper range instead of the truncated one. > > Nit: after reading this I thought you are passing some other parameter now. > But that is just a type change. I fixed both up, thanks! -- Cheers, David