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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 , Dev Jain , 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 , 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 Subject: Re: [PATCH v2 27/47] mm/mmu_gather: fix flushing ranges with 4 GiB or larger Date: Thu, 29 Oct 2026 17:57:25 -0700 Message-ID: <20261030005726.155279-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261029-fixes_core-v2-27-a64ce7f83abb@kernel.org> References: X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 81A151C0004 X-Stat-Signature: r316s1ht49g3ebk9xu1cspjd9i6uhzxr X-Rspamd-Server: rspam01 X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1793321856-807333 X-HE-Meta: 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 yoe4quIS 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Thu, 29 Oct 2026 21:33:22 +0100 "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 have 16 GiB hugetlb folios > mapped contiguously at the PMD level and flush them when unmapping, and a > 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 by > properly using "unsigned long" for range_size. Makes sense to me. > > Fix generated by an LLM and sent by Josef Bacik in private. > > Fixes: b528e4b6405b ("mm/hugetlb: add tlb_remove_hugetlb_entry for handling hugetlb pages") > Fixes: 8ce720d5bd91 ("mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather") > Cc: stable@vger.kernel.org > Signed-off-by: Josef Bacik > Acked-by: Lorenzo Stoakes (ARM) > [ david: use two-tab indent, simplify description ] It seems the convention [1] is to put the above modification note right before the last S-o-b: of David. Maybe you forgot moving it after adding R-b: and T-b: from great reviewers? > Reviewed-by: Qi Zheng > Reviewed-by: Gregory Price (Meta) > Tested-by: Gregory Price (Meta) > Reviewed-by: Dev Jain > Reviewed-by: Muchun Song > Reviewed-by: Pedro Falcato > Signed-off-by: David Hildenbrand (Arm) Reviewed-by: SJ Park [1] https://docs.kernel.org/maintainer/modifying-patches.html Thanks, SJ [...]