linux/Documentation/vm, branch v5.14

Merge branch 'akpm' (patches from Andrew)

2021-07-02T19:08:10Z

Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton : (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...

mm: device exclusive memory access

2021-07-01T18:06:03Z

Some devices require exclusive write access to shared virtual memory (SVM) ranges to perform atomic operations on that memory. This requires CPU page tables to be updated to deny access whilst atomic operations are occurring. In order to do this introduce a new swap entry type (SWP_DEVICE_EXCLUSIVE). When a SVM range needs to be marked for exclusive access by a device all page table mappings for the particular range are replaced with device exclusive swap entries. This causes any CPU access to the page to result in a fault. Faults are resovled by replacing the faulting entry with the original mapping. This results in MMU notifiers being called which a driver uses to update access permissions such as revoking atomic access. After notifiers have been called the device will no longer have exclusive access to the region. Walking of the page tables to find the target pages is handled by get_user_pages() rather than a direct page table walk. A direct page table walk similar to what migrate_vma_collect()/unmap() does could also have been utilised. However this resulted in more code similar in functionality to what get_user_pages() provides as page faulting is required to make the PTEs present and to break COW. [dan.carpenter@oracle.com: fix signedness bug in make_device_exclusive_range()] Link: https://lkml.kernel.org/r/YNIz5NVnZ5GiZ3u1@mwanda Link: https://lkml.kernel.org/r/20210616105937.23201-8-apopple@nvidia.com Signed-off-by: Alistair Popple Signed-off-by: Dan Carpenter Reviewed-by: Christoph Hellwig Cc: Ben Skeggs Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: "Matthew Wilcox (Oracle)" Cc: Peter Xu Cc: Ralph Campbell Cc: Shakeel Butt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: rename migrate_pgmap_owner

2021-07-01T18:06:03Z

MMU notifier ranges have a migrate_pgmap_owner field which is used by drivers to store a pointer. This is subsequently used by the driver callback to filter MMU_NOTIFY_MIGRATE events. Other notifier event types can also benefit from this filtering, so rename the 'migrate_pgmap_owner' field to 'owner' and create a new notifier initialisation function to initialise this field. Link: https://lkml.kernel.org/r/20210616105937.23201-6-apopple@nvidia.com Signed-off-by: Alistair Popple Suggested-by: Peter Xu Reviewed-by: Peter Xu Cc: Ben Skeggs Cc: Christoph Hellwig Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: "Matthew Wilcox (Oracle)" Cc: Ralph Campbell Cc: Shakeel Butt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/rmap: split try_to_munlock from try_to_unmap

2021-07-01T18:06:03Z

The behaviour of try_to_unmap_one() is difficult to follow because it performs different operations based on a fairly large set of flags used in different combinations. TTU_MUNLOCK is one such flag. However it is exclusively used by try_to_munlock() which specifies no other flags. Therefore rather than overload try_to_unmap_one() with unrelated behaviour split this out into it's own function and remove the flag. Link: https://lkml.kernel.org/r/20210616105937.23201-4-apopple@nvidia.com Signed-off-by: Alistair Popple Reviewed-by: Ralph Campbell Reviewed-by: Christoph Hellwig Cc: Ben Skeggs Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: John Hubbard Cc: "Matthew Wilcox (Oracle)" Cc: Peter Xu Cc: Shakeel Butt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patches from Andrew)

2021-06-30T00:29:11Z

Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton : (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...

docs: remove description of DISCONTIGMEM

2021-06-29T17:53:55Z

Remove description of DISCONTIGMEM from the "Memory Models" document and update VM sysctl description so that it won't mention DISCONIGMEM. Link: https://lkml.kernel.org/r/20210608091316.3622-8-rppt@kernel.org Signed-off-by: Mike Rapoport Acked-by: Arnd Bergmann Reviewed-by: David Hildenbrand Cc: Geert Uytterhoeven Cc: Ivan Kokshaysky Cc: Jonathan Corbet Cc: Matt Turner Cc: Richard Henderson Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'docs-5.14' of git://git.lwn.net/linux

2021-06-28T23:53:05Z

Pull documentation updates from Jonathan Corbet: "This was a reasonably active cycle for documentation; this includes: - Some kernel-doc cleanups. That script is still regex onslaught from hell, but it has gotten a little better. - Improvements to the checkpatch docs, which are also used by the tool itself. - A major update to the pathname lookup documentation. - Elimination of :doc: markup, since our automarkup magic can create references from filenames without all the extra noise. - The flurry of Chinese translation activity continues. Plus, of course, the usual collection of updates, typo fixes, and warning fixes" * tag 'docs-5.14' of git://git.lwn.net/linux: (115 commits) docs: path-lookup: use bare function() rather than literals docs: path-lookup: update symlink description docs: path-lookup: update get_link() ->follow_link description docs: path-lookup: update WALK_GET, WALK_PUT desc docs: path-lookup: no get_link() docs: path-lookup: update i_op->put_link and cookie description docs: path-lookup: i_op->follow_link replaced with i_op->get_link docs: path-lookup: Add macro name to symlink limit description docs: path-lookup: remove filename_mountpoint docs: path-lookup: update do_last() part docs: path-lookup: update path_mountpoint() part docs: path-lookup: update path_to_nameidata() part docs: path-lookup: update follow_managed() part docs: Makefile: Use CONFIG_SHELL not SHELL docs: Take a little noise out of the build process docs: x86: avoid using ReST :doc:`foo` markup docs: virt: kvm: s390-pv-boot.rst: avoid using ReST :doc:`foo` markup docs: userspace-api: landlock.rst: avoid using ReST :doc:`foo` markup docs: trace: ftrace.rst: avoid using ReST :doc:`foo` markup docs: trace: coresight: coresight.rst: avoid using ReST :doc:`foo` markup ...

docs: vm: zswap.rst: replace some characters

2021-06-17T19:22:33Z

The conversion tools used during DocBook/LaTeX/html/Markdown->ReST conversion and some cut-and-pasted text contain some characters that aren't easily reachable on standard keyboards and/or could cause troubles when parsed by the documentation build system. Replace the occurences of the following characters: - U+00a0 (' '): NO-BREAK SPACE as it can cause lines being truncated on PDF output Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/9a93b72f99f8f3328269076ceff50248ac9c5af5.1623826294.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet

mm/slub: clarify verification reporting

2021-06-16T16:24:42Z

Patch series "Actually fix freelist pointer vs redzoning", v4. This fixes redzoning vs the freelist pointer (both for middle-position and very small caches). Both are "theoretical" fixes, in that I see no evidence of such small-sized caches actually be used in the kernel, but that's no reason to let the bugs continue to exist, especially since people doing local development keep tripping over it. :) This patch (of 3): Instead of repeating "Redzone" and "Poison", clarify which sides of those zones got tripped. Additionally fix column alignment in the trailer. Before: BUG test (Tainted: G B ): Redzone overwritten ... Redzone (____ptrval____): bb bb bb bb bb bb bb bb ........ Object (____ptrval____): f6 f4 a5 40 1d e8 ...@.. Redzone (____ptrval____): 1a aa .. Padding (____ptrval____): 00 00 00 00 00 00 00 00 ........ After: BUG test (Tainted: G B ): Right Redzone overwritten ... Redzone (____ptrval____): bb bb bb bb bb bb bb bb ........ Object (____ptrval____): f6 f4 a5 40 1d e8 ...@.. Redzone (____ptrval____): 1a aa .. Padding (____ptrval____): 00 00 00 00 00 00 00 00 ........ The earlier commits that slowly resulted in the "Before" reporting were: d86bd1bece6f ("mm/slub: support left redzone") ffc79d288000 ("slub: use print_hex_dump") 2492268472e7 ("SLUB: change error reporting format to follow lockdep loosely") Link: https://lkml.kernel.org/r/20210608183955.280836-1-keescook@chromium.org Link: https://lkml.kernel.org/r/20210608183955.280836-2-keescook@chromium.org Link: https://lore.kernel.org/lkml/cfdb11d7-fb8e-e578-c939-f7f5fb69a6bd@suse.cz/ Signed-off-by: Kees Cook Acked-by: Vlastimil Babka Cc: Marco Elver Cc: "Lin, Zhenpeng" Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Roman Gushchin Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: gup: remove FOLL_SPLIT

2021-04-30T18:20:37Z

Since commit 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT") and commit ba925fa35057 ("s390/gmap: improve THP splitting") FOLL_SPLIT has not been used anymore. Remove the dead code. Link: https://lkml.kernel.org/r/20210330203900.9222-1-shy828301@gmail.com Signed-off-by: Yang Shi Reviewed-by: John Hubbard Reviewed-by: Jason Gunthorpe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds