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Dev Jain
d1bb71ec3a
[ Upstream commitf5407e9b69] Patch series "Fix incorrect access of hugetlb pte entries", v3. There are various places which use ptep_get() to get the pte entry corresponding to a hugetlb folio. Some arches (like s390) have special handling to compute the pteval, so they provide huge_ptep_get(). Use this helper consistently. Additionally, some code paths may provide huge_ptep_get with an unaligned address. This is a problem on arm64 (I checked other arches and it looks fine for them), which is fixed in patch 1. The fix is made to be backport-friendly: the cleaner fix would be to perhaps pass the hstate to huge_ptep_get() - that is wider churn and we can do that later. This patch (of 5): try_to_unmap_one() handles hugetlb folios when memory failure needs to replace a poisoned hugetlb mapping with a hwpoison entry. In that case page_vma_mapped_walk() returns the pte pointer to the hugetlb folio in pvmw.pte, but the code reads it with ptep_get(). On arches which provide their own huge_ptep_get() to dereference a huge pte pointer, accessing via ptep_get() would cause pte_pfn(), pte_present() etc to misbehave. It is not clear whether this has a trivially visible effect to userspace. Just use huge_ptep_get() for dereferencing a huge pte pointer. Link: https://lore.kernel.org/20260703114202.365553-1-dev.jain@arm.com Link: https://lore.kernel.org/20260703114202.365553-3-dev.jain@arm.com Fixes:c7ab0d2fdc("mm: convert try_to_unmap_one() to use page_vma_mapped_walk()") Signed-off-by: Dev Jain <dev.jain@arm.com> Reported-by: David Hildenbrand <david@kernel.org> Reviewed-by: Muchun Song <muchun.song@linux.dev> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Gregory Price <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jann Horn <jannh@google.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Jun'ichi "Nick" Nomura <j-nomura@ce.jp.nec.com> Cc: Kiryl Shutsemau <kas@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.