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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB66BC88CB6 for ; Mon, 12 Jun 2023 15:16:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238541AbjFLPQF (ORCPT ); Mon, 12 Jun 2023 11:16:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234242AbjFLPQD (ORCPT ); Mon, 12 Jun 2023 11:16:03 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9F82498 for ; Mon, 12 Jun 2023 08:16:01 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4E5FE1FB; Mon, 12 Jun 2023 08:16:46 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 628073F5A1; Mon, 12 Jun 2023 08:15:56 -0700 (PDT) From: Ryan Roberts To: Andrew Morton , SeongJae Park , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Mike Rapoport , Yu Zhao , Jason Gunthorpe , David Airlie , Daniel Vetter , Dimitri Sivanich , Alex Williamson , Oleksandr Tyshchenko , Alexander Viro , Christian Brauner , Mike Kravetz , Muchun Song , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Naoya Horiguchi , Miaohe Lin , Pasha Tatashin , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org, damon@lists.linux.dev Subject: [PATCH v3 0/3] Encapsulate PTE contents from non-arch code Date: Mon, 12 Jun 2023 16:15:42 +0100 Message-Id: <20230612151545.3317766-1-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi All, (Including wider audience this time since changes touch a fair few subsystems) This is the second half of v3 of a series to improve the encapsulation of pte entries by disallowing non-arch code from directly dereferencing pte_t pointers. Based on earlier feedback, I split the series in 2; the first part, fixes for existing bugs, was already posted at [3] and merged into mm-stable. This second part contains the conversion from direct dereferences to instead use ptep_get()/ptep_get_lockless(). See the v1 cover letter at [1] for rationale for this work. Based on feedback at v2, I've removed the new ptep_deref() helper I originally added, and am now using the existing ptep_get() and ptep_get_lockless() helpers. Testing on Ampere Altra (arm64) showed no difference in performance when using ptep_deref() (*pte) vs ptep_get() (READ_ONCE(*pte)). Patches are based on mm-unstable (49e038b1919e) and a branch is available at [4] (Let me know if this is the wrong branch to target - I'm still not familiar with the details of the mm- dev process!). Note that Hugh Dickins's "mm: allow pte_offset_map[_lock]() to fail" (now in mm-unstable) patch set caused a number of conflicts which I've resolved. But due to that, you won't be able to apply these patches on top of Linus's tree. I have an alternate branch on top of v6.4-rc6 at [5]. Changes since v2 [2]: - Removed ptep_deref() helper - Converted ptep_deref() callsites to use ptep_get[_lockless]() Changes since v1 [1]: - Fixed sh build bug reported by 0-day CI [1] https://lore.kernel.org/linux-mm/20230511132113.80196-1-ryan.roberts@arm.com/ [2] https://lore.kernel.org/linux-mm/20230518110727.2106156-1-ryan.roberts@arm.com/ [3] https://lore.kernel.org/all/20230602092949.545577-1-ryan.roberts@arm.com/ [4] https://gitlab.arm.com/linux-arm/linux-rr/-/tree/features/granule_perf/ptep_get-mm-unstable-lkml_v3 [5] https://gitlab.arm.com/linux-arm/linux-rr/-/tree/features/granule_perf/ptep_get-v6.4-rc6-lkml_v3 Thanks, Ryan Ryan Roberts (3): mm: ptdump should use ptep_get_lockless() mm: Move ptep_get() and pmdp_get() helpers mm: ptep_get() conversion .../drm/i915/gem/selftests/i915_gem_mman.c | 8 +- drivers/misc/sgi-gru/grufault.c | 2 +- drivers/vfio/vfio_iommu_type1.c | 7 +- drivers/xen/privcmd.c | 2 +- fs/proc/task_mmu.c | 33 +++--- fs/userfaultfd.c | 6 +- include/linux/hugetlb.h | 4 + include/linux/mm_inline.h | 2 +- include/linux/pgtable.h | 34 +++--- kernel/events/uprobes.c | 2 +- mm/damon/ops-common.c | 2 +- mm/damon/paddr.c | 2 +- mm/damon/vaddr.c | 10 +- mm/filemap.c | 2 +- mm/gup.c | 21 ++-- mm/highmem.c | 12 ++- mm/hmm.c | 2 +- mm/huge_memory.c | 4 +- mm/hugetlb.c | 2 +- mm/hugetlb_vmemmap.c | 6 +- mm/kasan/init.c | 9 +- mm/kasan/shadow.c | 10 +- mm/khugepaged.c | 22 ++-- mm/ksm.c | 22 ++-- mm/madvise.c | 6 +- mm/mapping_dirty_helpers.c | 4 +- mm/memcontrol.c | 4 +- mm/memory-failure.c | 26 ++--- mm/memory.c | 100 ++++++++++-------- mm/mempolicy.c | 6 +- mm/migrate.c | 14 +-- mm/migrate_device.c | 15 +-- mm/mincore.c | 2 +- mm/mlock.c | 6 +- mm/mprotect.c | 8 +- mm/mremap.c | 2 +- mm/page_table_check.c | 4 +- mm/page_vma_mapped.c | 27 +++-- mm/pgtable-generic.c | 2 +- mm/ptdump.c | 2 +- mm/rmap.c | 34 +++--- mm/sparse-vmemmap.c | 8 +- mm/swap_state.c | 8 +- mm/swapfile.c | 20 ++-- mm/userfaultfd.c | 4 +- mm/vmalloc.c | 6 +- mm/vmscan.c | 14 +-- virt/kvm/kvm_main.c | 11 +- 48 files changed, 316 insertions(+), 243 deletions(-) -- 2.25.1