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From: Muchun Song In-Reply-To: <20260703114202.365553-2-dev.jain@arm.com> Date: Sat, 4 Jul 2026 10:42:45 +0800 Cc: osalvador@suse.de, akpm@linux-foundation.org, ljs@kernel.org, david@kernel.org, liam@infradead.org, riel@surriel.com, vbabka@kernel.org, harry@kernel.org, jannh@google.com, lance.yang@linux.dev, kas@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, apopple@nvidia.com, rcampbell@nvidia.com, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, ak@linux.intel.com, nao.horiguchi@gmail.com, mel@csn.ul.ie, j-nomura@ce.jp.nec.com, pfalcato@suse.de, tglx@kernel.org, dave.hansen@intel.com, jpoimboe@kernel.org, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, ryan.roberts@arm.com, anshuman.khandual@arm.com, stable@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <58500686-A4A0-45FD-872D-AB0EE2AD2ACC@linux.dev> References: <20260703114202.365553-1-dev.jain@arm.com> <20260703114202.365553-2-dev.jain@arm.com> To: Dev Jain X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 5271540002 X-Stat-Signature: z94egau56mbibjp3i4ude56ipxjohxc7 X-Rspam-User: X-HE-Tag: 1783133011-881465 X-HE-Meta: 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 uaFKDwT5 3Hi8TSox8MGpRPZBgmbN4clawngZdp4e7Jk+XjBBaYjlRVcIh91v4LGRNhiahb0asieA6iys6535yFsMrhGb1POvOhSCPEQ3ASpfcNIRA8IjHUh7Ge0q6ADwyib8x+yD0s02qDYIfKPdtBVR9FYUvyYO8p4IFRukgFUXUaEyPukn9/2c4y6cVEI+XSLvPYJ9lIYkTNcQlYGiGLFq+HAKD8olYhVAjgoXyCsARxbv62FCwafvI10fSpd1o74VaEz9YaRyS1ijMjG7nUCbAD8uYdF/ZJ30rQNu6nt+c6iQ7JJbelSH4cDAJl0bJUEtgPJHtkcvM2XMb4/R4+F/bhtwR21GApMjUIKkIiPnlk2Tkty8MCGBce/2tVHpx9vM3S8ZlMRXU3lshX9DIYy4j/Jv5XJR/gAo0E2KhxB39AIPJCpS00CQVeEie0rGsBh7PyhGilTfq Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Jul 3, 2026, at 19:41, Dev Jain wrote: >=20 > huge_ptep_get() can be handed a virtual address pointing to the middle = of > a contpmd/contpte mapped hugetlb folio (examples of callers are > pagemap_hugetlb_range, page_mapped_in_vma). >=20 > The arm64 helper rewalks the pgtables in find_num_contig to answer = whether > the huge pte we have maps a contpmd or a contpte hugetlb folio, and > returns CONT_PMDS or CONT_PTES, so that it can collect a/d bits over = the > contiguous ptes. We can falsely return CONT_PTES instead of CONT_PMDS > if the addr is not aligned. >=20 > Fix this by aligning the pmdp pointer down to a contpmd base before > checking equality with the passed huge pte pointer, to correctly = answer > whether the huge pte is the base of a contpmd block. >=20 > Fixes: 29cb80519689 ("arm64: hugetlb: Cleanup huge_pte size discovery = mechanisms") > Cc: stable@vger.kernel.org > Acked-by: David Hildenbrand (Arm) > Signed-off-by: Dev Jain Acked-by: Muchun Song Thanks.