kernel.git/arch/arm64/mm, branch linux-5.18.y

arm64: kasan: Revert "arm64: mte: reset the page tag in page->flags"

2022-08-17T12:40:20Z

[ Upstream commit 20794545c14692094a882d2221c251c4573e6adf ] This reverts commit e5b8d9218951e59df986f627ec93569a0d22149b. Pages mapped in user-space with PROT_MTE have the allocation tags either zeroed or copied/restored to some user values. In order for the kernel to access such pages via page_address(), resetting the tag in page->flags was necessary. This tag resetting was deferred to set_pte_at() -> mte_sync_page_tags() but it can race with another CPU reading the flags (via page_to_virt()): P0 (mte_sync_page_tags): P1 (memcpy from virt_to_page): Rflags!=0xff Wflags=0xff DMB (doesn't help) Wtags=0 Rtags=0 // fault Since now the post_alloc_hook() function resets the page->flags tag when unpoisoning is skipped for user pages (including the __GFP_ZEROTAGS case), revert the arm64 commit calling page_kasan_tag_reset(). Signed-off-by: Catalin Marinas Cc: Will Deacon Cc: Vincenzo Frascino Cc: Andrey Konovalov Cc: Peter Collingbourne Reviewed-by: Vincenzo Frascino Acked-by: Andrey Konovalov Link: https://lore.kernel.org/r/20220610152141.2148929-5-catalin.marinas@arm.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

arm64: mm: Don't invalidate FROM_DEVICE buffers at start of DMA transfer

2022-06-22T12:28:06Z

commit c50f11c6196f45c92ca48b16a5071615d4ae0572 upstream. Invalidating the buffer memory in arch_sync_dma_for_device() for FROM_DEVICE transfers When using the streaming DMA API to map a buffer prior to inbound non-coherent DMA (i.e. DMA_FROM_DEVICE), we invalidate any dirty CPU cachelines so that they will not be written back during the transfer and corrupt the buffer contents written by the DMA. This, however, poses two potential problems: (1) If the DMA transfer does not write to every byte in the buffer, then the unwritten bytes will contain stale data once the transfer has completed. (2) If the buffer has a virtual alias in userspace, then stale data may be visible via this alias during the period between performing the cache invalidation and the DMA writes landing in memory. Address both of these issues by cleaning (aka writing-back) the dirty lines in arch_sync_dma_for_device(DMA_FROM_DEVICE) instead of discarding them using invalidation. Cc: Ard Biesheuvel Cc: Christoph Hellwig Cc: Robin Murphy Cc: Russell King Cc: Link: https://lore.kernel.org/r/20220606152150.GA31568@willie-the-truck Signed-off-by: Will Deacon Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20220610151228.4562-2-will@kernel.org Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: fix types in copy_highpage()

2022-06-09T08:30:06Z

[ Upstream commit 921d161f15d6b090599f6a8c23f131969edbd1fa ] In copy_highpage() the `kto` and `kfrom` local variables are pointers to struct page, but these are used to hold arbitrary pointers to kernel memory . Each call to page_address() returns a void pointer to memory associated with the relevant page, and copy_page() expects void pointers to this memory. This inconsistency was introduced in commit 2563776b41c3 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations") and while this doesn't appear to be harmful in practice it is clearly wrong. Correct this by making `kto` and `kfrom` void pointers. Fixes: 2563776b41c3 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations") Signed-off-by: Tong Tiangen Acked-by: Mark Rutland Reviewed-by: Kefeng Wang Link: https://lore.kernel.org/r/20220420030418.3189040-3-tongtiangen@huawei.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map

2022-05-10T00:34:28Z

The semantics of pfn_valid() is to check presence of the memory map for a PFN and not whether a PFN is covered by the linear map. The memory map may be present for NOMAP memory regions, but they won't be mapped in the linear mapping. Accessing such regions via __va() when they are memremap()'ed will cause a crash. On v5.4.y the crash happens on qemu-arm with UEFI [1]: <1>[ 0.084476] 8<--- cut here --- <1>[ 0.084595] Unable to handle kernel paging request at virtual address dfb76000 <1>[ 0.084938] pgd = (ptrval) <1>[ 0.085038] [dfb76000] *pgd=5f7fe801, *pte=00000000, *ppte=00000000 ... <4>[ 0.093923] [] (memcpy) from [] (dmi_setup+0x60/0x418) <4>[ 0.094204] [] (dmi_setup) from [] (arm_dmi_init+0x8/0x10) <4>[ 0.094408] [] (arm_dmi_init) from [] (do_one_initcall+0x50/0x228) <4>[ 0.094619] [] (do_one_initcall) from [] (kernel_init_freeable+0x15c/0x1f8) <4>[ 0.094841] [] (kernel_init_freeable) from [] (kernel_init+0x8/0x10c) <4>[ 0.095057] [] (kernel_init) from [] (ret_from_fork+0x14/0x2c) On kernels v5.10.y and newer the same crash won't reproduce on ARM because commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") changed the way memory regions are registered in the resource tree, but that merely covers up the problem. On ARM64 memory resources registered in yet another way and there the issue of wrong usage of pfn_valid() to ensure availability of the linear map is also covered. Implement arch_memremap_can_ram_remap() on ARM and ARM64 to prevent access to NOMAP regions via the linear mapping in memremap(). Link: https://lore.kernel.org/all/Yl65zxGgFzF1Okac@sirena.org.uk Link: https://lkml.kernel.org/r/20220426060107.7618-1-rppt@kernel.org Signed-off-by: Mike Rapoport Reported-by: "kernelci.org bot" Tested-by: Mark Brown Reviewed-by: Ard Biesheuvel Acked-by: Catalin Marinas Cc: Greg Kroah-Hartman Cc: Mark Brown Cc: Mark-PK Tsai Cc: Russell King Cc: Tony Lindgren Cc: Will Deacon Cc: [5.4+] Signed-off-by: Andrew Morton

arm64: fix typos in comments

2022-04-04T09:32:50Z

Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Link: https://lore.kernel.org/r/20220318103729.157574-10-Julia.Lawall@inria.fr [will: Squashed in 20220318103729.157574-28-Julia.Lawall@inria.fr] Signed-off-by: Will Deacon

kasan, arm64: don't tag executable vmalloc allocations

2022-03-25T02:06:48Z

Besides asking vmalloc memory to be executable via the prot argument of __vmalloc_node_range() (see the previous patch), the kernel can skip that bit and instead mark memory as executable via set_memory_x(). Once tag-based KASAN modes start tagging vmalloc allocations, executing code from such allocations will lead to the PC register getting a tag, which is not tolerated by the kernel. Generic kernel code typically allocates memory via module_alloc() if it intends to mark memory as executable. (On arm64 module_alloc() uses __vmalloc_node_range() without setting the executable bit). Thus, reset pointer tags of pointers returned from module_alloc(). However, on arm64 there's an exception: the eBPF subsystem. Instead of using module_alloc(), it uses vmalloc() (via bpf_jit_alloc_exec()) to allocate its JIT region. Thus, reset pointer tags of pointers returned from bpf_jit_alloc_exec(). Resetting tags for these pointers results in untagged pointers being passed to set_memory_x(). This causes conflicts in arithmetic checks in change_memory_common(), as vm_struct->addr pointer returned by find_vm_area() is tagged. Reset pointer tag of find_vm_area(addr)->addr in change_memory_common(). Link: https://lkml.kernel.org/r/b7b2595423340cd7d76b770e5d519acf3b72f0ab.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Catalin Marinas Acked-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Mark Rutland Cc: Peter Collingbourne Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patches from Andrew)

2022-03-24T21:14:07Z

Merge more updates from Andrew Morton: "Various misc subsystems, before getting into the post-linux-next material. 41 patches. Subsystems affected by this patch series: procfs, misc, core-kernel, lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump, taskstats, panic, kcov, resource, and ubsan" * emailed patches from Andrew Morton : (41 commits) Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang" kernel/resource: fix kfree() of bootmem memory again kcov: properly handle subsequent mmap calls kcov: split ioctl handling into locked and unlocked parts panic: move panic_print before kmsg dumpers panic: add option to dump all CPUs backtraces in panic_print docs: sysctl/kernel: add missing bit to panic_print taskstats: remove unneeded dead assignment kasan: no need to unset panic_on_warn in end_report() ubsan: no need to unset panic_on_warn in ubsan_epilogue() panic: unset panic_on_warn inside panic() docs: kdump: add scp example to write out the dump file docs: kdump: update description about sysfs file system support arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible cgroup: use irqsave in cgroup_rstat_flush_locked(). fat: use pointer to simple type in put_user() minix: fix bug when opening a file with O_DIRECT ...

arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef

2022-03-24T02:00:34Z

Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" by a check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code and increase compile coverage. Link: https://lkml.kernel.org/r/20211206160514.2000-5-jszhang@kernel.org Signed-off-by: Jisheng Zhang Acked-by: Catalin Marinas Acked-by: Baoquan He Cc: Albert Ou Cc: Alexandre Ghiti Cc: Borislav Petkov Cc: Dave Hansen Cc: Eric W. Biederman Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Palmer Dabbelt Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Russell King Cc: Russell King (Oracle) Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache

2022-03-23T00:03:12Z

Pull folio updates from Matthew Wilcox: - Rewrite how munlock works to massively reduce the contention on i_mmap_rwsem (Hugh Dickins): https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/ - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig): https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/ - Convert GUP to use folios and make pincount available for order-1 pages. (Matthew Wilcox) - Convert a few more truncation functions to use folios (Matthew Wilcox) - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox) - Convert rmap_walk to use folios (Matthew Wilcox) - Convert most of shrink_page_list() to use a folio (Matthew Wilcox) - Add support for creating large folios in readahead (Matthew Wilcox) * tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits) mm/damon: minor cleanup for damon_pa_young selftests/vm/transhuge-stress: Support file-backed PMD folios mm/filemap: Support VM_HUGEPAGE for file mappings mm/readahead: Switch to page_cache_ra_order mm/readahead: Align file mappings for non-DAX mm/readahead: Add large folio readahead mm: Support arbitrary THP sizes mm: Make large folios depend on THP mm: Fix READ_ONLY_THP warning mm/filemap: Allow large folios to be added to the page cache mm: Turn can_split_huge_page() into can_split_folio() mm/vmscan: Convert pageout() to take a folio mm/vmscan: Turn page_check_references() into folio_check_references() mm/vmscan: Account large folios correctly mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios mm/vmscan: Free non-shmem folios without splitting them mm/rmap: Constify the rmap_walk_control argument mm/rmap: Convert rmap_walk() to take a folio mm: Turn page_anon_vma() into folio_anon_vma() mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read() ...

Merge branch 'akpm' (patches from Andrew)

2022-03-22T23:11:53Z

Merge updates from Andrew Morton: - A few misc subsystems: kthread, scripts, ntfs, ocfs2, block, and vfs - Most the MM patches which precede the patches in Willy's tree: kasan, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, sparsemem, vmalloc, pagealloc, memory-failure, mlock, hugetlb, userfaultfd, vmscan, compaction, mempolicy, oom-kill, migration, thp, cma, autonuma, psi, ksm, page-poison, madvise, memory-hotplug, rmap, zswap, uaccess, ioremap, highmem, cleanups, kfence, hmm, and damon. * emailed patches from Andrew Morton : (227 commits) mm/damon/sysfs: remove repeat container_of() in damon_sysfs_kdamond_release() Docs/ABI/testing: add DAMON sysfs interface ABI document Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface selftests/damon: add a test for DAMON sysfs interface mm/damon/sysfs: support DAMOS stats mm/damon/sysfs: support DAMOS watermarks mm/damon/sysfs: support schemes prioritization mm/damon/sysfs: support DAMOS quotas mm/damon/sysfs: support DAMON-based Operation Schemes mm/damon/sysfs: support the physical address space monitoring mm/damon/sysfs: link DAMON for virtual address spaces monitoring mm/damon: implement a minimal stub for sysfs-based DAMON interface mm/damon/core: add number of each enum type values mm/damon/core: allow non-exclusive DAMON start/stop Docs/damon: update outdated term 'regions update interval' Docs/vm/damon/design: update DAMON-Idle Page Tracking interference handling Docs/vm/damon: call low level monitoring primitives the operations mm/damon: remove unnecessary CONFIG_DAMON option mm/damon/paddr,vaddr: remove damon_{p,v}a_{target_valid,set_operations}() mm/damon/dbgfs-test: fix is_target_id() change ...