linux/mm/sparse-vmemmap.c, branch v6.4

mm/vmemmap/devdax: fix kernel crash when probing devdax devices

2023-04-18T23:30:09Z

commit 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") added support for using optimized vmmemap for devdax devices. But how vmemmap mappings are created are architecture specific. For example, powerpc with hash translation doesn't have vmemmap mappings in init_mm page table instead they are bolted table entries in the hardware page table vmemmap_populate_compound_pages() used by vmemmap optimization code is not aware of these architecture-specific mapping. Hence allow architecture to opt for this feature. I selected architectures supporting HUGETLB_PAGE_OPTIMIZE_VMEMMAP option as also supporting this feature. This patch fixes the below crash on ppc64. BUG: Unable to handle kernel data access on write at 0xc00c000100400038 Faulting instruction address: 0xc000000001269d90 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc5-150500.34-default+ #2 5c90a668b6bbd142599890245c2fb5de19d7d28a Hardware name: IBM,9009-42G POWER9 (raw) 0x4e0202 0xf000005 of:IBM,FW950.40 (VL950_099) hv:phyp pSeries NIP: c000000001269d90 LR: c0000000004c57d4 CTR: 0000000000000000 REGS: c000000003632c30 TRAP: 0300 Not tainted (6.3.0-rc5-150500.34-default+) MSR: 8000000000009033 CR: 24842228 XER: 00000000 CFAR: c0000000004c57d0 DAR: c00c000100400038 DSISR: 42000000 IRQMASK: 0 .... NIP [c000000001269d90] __init_single_page.isra.74+0x14/0x4c LR [c0000000004c57d4] __init_zone_device_page+0x44/0xd0 Call Trace: [c000000003632ed0] [c000000003632f60] 0xc000000003632f60 (unreliable) [c000000003632f10] [c0000000004c5ca0] memmap_init_zone_device+0x170/0x250 [c000000003632fe0] [c0000000005575f8] memremap_pages+0x2c8/0x7f0 [c0000000036330c0] [c000000000557b5c] devm_memremap_pages+0x3c/0xa0 [c000000003633100] [c000000000d458a8] dev_dax_probe+0x108/0x3e0 [c0000000036331a0] [c000000000d41430] dax_bus_probe+0xb0/0x140 [c0000000036331d0] [c000000000cef27c] really_probe+0x19c/0x520 [c000000003633260] [c000000000cef6b4] __driver_probe_device+0xb4/0x230 [c0000000036332e0] [c000000000cef888] driver_probe_device+0x58/0x120 [c000000003633320] [c000000000cefa6c] __device_attach_driver+0x11c/0x1e0 [c0000000036333a0] [c000000000cebc58] bus_for_each_drv+0xa8/0x130 [c000000003633400] [c000000000ceefcc] __device_attach+0x15c/0x250 [c0000000036334a0] [c000000000ced458] bus_probe_device+0x108/0x110 [c0000000036334f0] [c000000000ce92dc] device_add+0x7fc/0xa10 [c0000000036335b0] [c000000000d447c8] devm_create_dev_dax+0x1d8/0x530 [c000000003633640] [c000000000d46b60] __dax_pmem_probe+0x200/0x270 [c0000000036337b0] [c000000000d46bf0] dax_pmem_probe+0x20/0x70 [c0000000036337d0] [c000000000d2279c] nvdimm_bus_probe+0xac/0x2b0 [c000000003633860] [c000000000cef27c] really_probe+0x19c/0x520 [c0000000036338f0] [c000000000cef6b4] __driver_probe_device+0xb4/0x230 [c000000003633970] [c000000000cef888] driver_probe_device+0x58/0x120 [c0000000036339b0] [c000000000cefd08] __driver_attach+0x1d8/0x240 [c000000003633a30] [c000000000cebb04] bus_for_each_dev+0xb4/0x130 [c000000003633a90] [c000000000cee564] driver_attach+0x34/0x50 [c000000003633ab0] [c000000000ced878] bus_add_driver+0x218/0x300 [c000000003633b40] [c000000000cf1144] driver_register+0xa4/0x1b0 [c000000003633bb0] [c000000000d21a0c] __nd_driver_register+0x5c/0x100 [c000000003633c10] [c00000000206a2e8] dax_pmem_init+0x34/0x48 [c000000003633c30] [c0000000000132d0] do_one_initcall+0x60/0x320 [c000000003633d00] [c0000000020051b0] kernel_init_freeable+0x360/0x400 [c000000003633de0] [c000000000013764] kernel_init+0x34/0x1d0 [c000000003633e50] [c00000000000de14] ret_from_kernel_thread+0x5c/0x64 Link: https://lkml.kernel.org/r/20230411142214.64464-1-aneesh.kumar@linux.ibm.com Fixes: 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") Signed-off-by: Aneesh Kumar K.V Reported-by: Tarun Sahu Reviewed-by: Joao Martins Cc: Muchun Song Cc: Dan Williams Cc: Mike Kravetz Cc: Signed-off-by: Andrew Morton

mm/sparse-vmemmap: generalise vmemmap_populate_hugepages()

2022-12-12T02:12:12Z

Generalise vmemmap_populate_hugepages() so ARM64 & X86 & LoongArch can share its implementation. Link: https://lkml.kernel.org/r/20221027125253.3458989-4-chenhuacai@loongson.cn Signed-off-by: Feiyang Chen Signed-off-by: Huacai Chen Acked-by: Will Deacon Acked-by: Dave Hansen Reviewed-by: Arnd Bergmann Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Dinh Nguyen Cc: Guo Ren Cc: Jiaxun Yang Cc: Min Zhou Cc: Peter Zijlstra Cc: Philippe Mathieu-Daudé Cc: Thomas Bogendoerfer Cc: Xuefeng Li Cc: Xuerui Wang Cc: Muchun Song Signed-off-by: Andrew Morton

LoongArch: add sparse memory vmemmap support

2022-12-12T02:12:12Z

Add sparse memory vmemmap support for LoongArch. SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise pfn_to_page and page_to_pfn operations. This is the most efficient option when sufficient kernel resources are available. Link: https://lkml.kernel.org/r/20221027125253.3458989-3-chenhuacai@loongson.cn Signed-off-by: Min Zhou Signed-off-by: Feiyang Chen Signed-off-by: Huacai Chen Reviewed-by: Arnd Bergmann Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Dave Hansen Cc: Dinh Nguyen Cc: Guo Ren Cc: Jiaxun Yang Cc: Peter Zijlstra Cc: Philippe Mathieu-Daudé Cc: Thomas Bogendoerfer Cc: Will Deacon Cc: Xuefeng Li Cc: Xuerui Wang Cc: Muchun Song Signed-off-by: Andrew Morton

mm: hugetlb_vmemmap: move vmemmap code related to HugeTLB to hugetlb_vmemmap.c

2022-08-09T01:06:42Z

When I first introduced vmemmap manipulation functions related to HugeTLB, I thought those functions may be reused by other modules (e.g. using similar approach to optimize vmemmap pages, unfortunately, the DAX used the same approach but does not use those functions). After two years, we didn't see any other users. So move those functions to hugetlb_vmemmap.c. Code movement without any functional change. Link: https://lkml.kernel.org/r/20220628092235.91270-5-songmuchun@bytedance.com Signed-off-by: Muchun Song Reviewed-by: Oscar Salvador Reviewed-by: Mike Kravetz Cc: Anshuman Khandual Cc: Catalin Marinas Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Will Deacon Cc: Xiongchun Duan Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-08-05T23:32:45Z

Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...

Merge tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

2022-08-03T21:38:02Z

Pull EFI updates from Ard Biesheuvel: - Enable mirrored memory for arm64 - Fix up several abuses of the efivar API - Refactor the efivar API in preparation for moving the 'business logic' part of it into efivarfs - Enable ACPI PRM on arm64 * tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits) ACPI: Move PRM config option under the main ACPI config ACPI: Enable Platform Runtime Mechanism(PRM) support on ARM64 ACPI: PRM: Change handler_addr type to void pointer efi: Simplify arch_efi_call_virt() macro drivers: fix typo in firmware/efi/memmap.c efi: vars: Drop __efivar_entry_iter() helper which is no longer used efi: vars: Use locking version to iterate over efivars linked lists efi: pstore: Omit efivars caching EFI varstore access layer efi: vars: Add thin wrapper around EFI get/set variable interface efi: vars: Don't drop lock in the middle of efivar_init() pstore: Add priv field to pstore_record for backend specific use Input: applespi - avoid efivars API and invoke EFI services directly selftests/kexec: remove broken EFI_VARS secure boot fallback check brcmfmac: Switch to appropriate helper to load EFI variable contents iwlwifi: Switch to proper EFI variable store interface media: atomisp_gmin_platform: stop abusing efivar API efi: efibc: avoid efivar API for setting variables efi: avoid efivars layer when loading SSDTs from variables efi: Correct comment on efi_memmap_alloc memblock: Disable mirror feature if kernelcore is not specified ...

mm: sparsemem: drop unexpected word 'a' in comments

2022-07-04T01:08:50Z

there is an unexpected word 'a' in the comments that need to be dropped Link: https://lkml.kernel.org/r/24fbdae3.c86.1819a0f31b9.Coremail.chenxuebing@jari.cn Signed-off-by: XueBing Chen Signed-off-by: Andrew Morton

mm: sparsemem: fix missing higher order allocation splitting

2022-07-03T22:42:32Z

Higher order allocations for vmemmap pages from buddy allocator must be able to be treated as indepdenent small pages as they can be freed individually by the caller. There is no problem for higher order vmemmap pages allocated at boot time since each individual small page will be initialized at boot time. However, it will be an issue for memory hotplug case since those higher order vmemmap pages are allocated from buddy allocator without initializing each individual small page's refcount. The system will panic in put_page_testzero() when CONFIG_DEBUG_VM is enabled if the vmemmap page is freed. Link: https://lkml.kernel.org/r/20220620023019.94257-1-songmuchun@bytedance.com Fixes: d8d55f5616cf ("mm: sparsemem: use page table lock to protect kernel pmd operations") Signed-off-by: Muchun Song Reviewed-by: Mike Kravetz Cc: Xiongchun Duan Cc: Signed-off-by: Andrew Morton

docs: rename Documentation/vm to Documentation/mm

2022-06-27T19:52:53Z

so it will be consistent with code mm directory and with Documentation/admin-guide/mm and won't be confused with virtual machines. Signed-off-by: Mike Rapoport Suggested-by: Matthew Wilcox Tested-by: Ira Weiny Acked-by: Jonathan Corbet Acked-by: Wu XiangCheng

mm/sparse-vmemmap.c: remove unwanted initialization in vmemmap_populate_compound_pages()

2022-06-17T02:48:32Z

Remove unnecessary initialization for the variable 'next'. This fixes the clang scan warning: Value stored to 'next' during its initialization is never read [deadcode.DeadStores] Link: https://lkml.kernel.org/r/20220612182320.160651-1-gautammenghani201@gmail.com Signed-off-by: Gautam Menghani Reviewed-by: David Hildenbrand Reviewed-by: Muchun Song Reviewed-by: Joao Martins Reviewed-by: Oscar Salvador Signed-off-by: Andrew Morton