kernel/git/stable/linux.git/mm/memory-failure.c, branch linux-6.4.y

mm: memory-failure: fix unexpected return value in soft_offline_page()

2023-08-30T12:52:39+00:00

commit e2c1ab070fdc81010ec44634838d24fce9ff9e53 upstream. When page_handle_poison() fails to handle the hugepage or free page in retry path, soft_offline_page() will return 0 while -EBUSY is expected in this case. Consequently the user will think soft_offline_page succeeds while it in fact failed. So the user will not try again later in this case. Link: https://lkml.kernel.org/r/20230627112808.1275241-1-linmiaohe@huawei.com Fixes: b94e02822deb ("mm,hwpoison: try to narrow window race for free pages") Signed-off-by: Miaohe Lin Acked-by: Naoya Horiguchi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm: enable page walking API to lock vmas during the walk

2023-08-30T12:52:36+00:00

commit 49b0638502da097c15d46cd4e871dbaa022caf7c upstream. walk_page_range() and friends often operate under write-locked mmap_lock. With introduction of vma locks, the vmas have to be locked as well during such walks to prevent concurrent page faults in these areas. Add an additional member to mm_walk_ops to indicate locking requirements for the walk. The change ensures that page walks which prevent concurrent page faults by write-locking mmap_lock, operate correctly after introduction of per-vma locks. With per-vma locks page faults can be handled under vma lock without taking mmap_lock at all, so write locking mmap_lock would not stop them. The change ensures vmas are properly locked during such walks. A sample issue this solves is do_mbind() performing queue_pages_range() to queue pages for migration. Without this change a concurrent page can be faulted into the area and be left out of migration. Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com Signed-off-by: Suren Baghdasaryan Suggested-by: Linus Torvalds Suggested-by: Jann Horn Cc: David Hildenbrand Cc: Davidlohr Bueso Cc: Hugh Dickins Cc: Johannes Weiner Cc: Laurent Dufour Cc: Liam Howlett Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Michel Lespinasse Cc: Peter Xu Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm: memory-failure: avoid false hwpoison page mapped error info

2023-08-16T16:32:20+00:00

commit faeb2ff2c1c5cb60ce0da193580b256c941f99ca upstream. folio->_mapcount is overloaded in SLAB, so folio_mapped() has to be done after folio_test_slab() is checked. Otherwise slab folio might be treated as a mapped folio leading to false 'Someone maps the hwpoison page' error info. Link: https://lkml.kernel.org/r/20230727115643.639741-4-linmiaohe@huawei.com Fixes: 230ac719c500 ("mm/hwpoison: don't try to unpoison containment-failed pages") Signed-off-by: Miaohe Lin Reviewed-by: Matthew Wilcox (Oracle) Acked-by: Naoya Horiguchi Cc: Kefeng Wang Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm: memory-failure: fix potential unexpected return value from unpoison_memory()

2023-08-16T16:32:20+00:00

commit f29623e4a599c295cc8f518c8e4bb7848581a14d upstream. If unpoison_memory() fails to clear page hwpoisoned flag, return value ret is expected to be -EBUSY. But when get_hwpoison_page() returns 1 and fails to clear page hwpoisoned flag due to races, return value will be unexpected 1 leading to users being confused. And there's a code smell that the variable "ret" is used not only to save the return value of unpoison_memory(), but also the return value from get_hwpoison_page(). Make a further cleanup by using another auto-variable solely to save the return value of get_hwpoison_page() as suggested by Naoya. Link: https://lkml.kernel.org/r/20230727115643.639741-3-linmiaohe@huawei.com Fixes: bf181c582588 ("mm/hwpoison: fix unpoison_memory()") Signed-off-by: Miaohe Lin Cc: Kefeng Wang Cc: Matthew Wilcox (Oracle) Cc: Naoya Horiguchi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm/memory-failure: fix hardware poison check in unpoison_memory()

2023-08-03T08:26:14+00:00

commit 6c54312f9689fbe27c70db5d42eebd29d04b672e upstream. It was pointed out[1] that using folio_test_hwpoison() is wrong as we need to check the indiviual page that has poison. folio_test_hwpoison() only checks the head page so go back to using PageHWPoison(). User-visible effects include existing hwpoison-inject tests possibly failing as unpoisoning a single subpage could lead to unpoisoning an entire folio. Memory unpoisoning could also not work as expected as the function will break early due to only checking the head page and not the actually poisoned subpage. [1]: https://lore.kernel.org/lkml/ZLIbZygG7LqSI9xe@casper.infradead.org/ Link: https://lkml.kernel.org/r/20230717181812.167757-1-sidhartha.kumar@oracle.com Fixes: a6fddef49eef ("mm/memory-failure: convert unpoison_memory() to folios") Signed-off-by: Sidhartha Kumar Reported-by: Matthew Wilcox (Oracle) Acked-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-04-28T02:42:02+00:00

Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...

mm: ksm: support hwpoison for ksm page

2023-04-18T23:53:52+00:00

hwpoison_user_mappings() is updated to support ksm pages, and add collect_procs_ksm() to collect processes when the error hit an ksm page. The difference from collect_procs_anon() is that it also needs to traverse the rmap-item list on the stable node of the ksm page. At the same time, add_to_kill_ksm() is added to handle ksm pages. And task_in_to_kill_list() is added to avoid duplicate addition of tsk to the to_kill list. This is because when scanning the list, if the pages that make up the ksm page all come from the same process, they may be added repeatedly. Link: https://lkml.kernel.org/r/20230414021741.2597273-3-xialonglong1@huawei.com Signed-off-by: Longlong Xia Tested-by: Naoya Horiguchi Reviewed-by: Kefeng Wang Cc: Miaohe Lin Cc: Nanyong Sun Signed-off-by: Andrew Morton

mm: memory-failure: refactor add_to_kill()

2023-04-18T23:53:52+00:00

Patch series "mm: ksm: support hwpoison for ksm page", v2. Currently, ksm does not support hwpoison. As ksm is being used more widely for deduplication at the system level, container level, and process level, supporting hwpoison for ksm has become increasingly important. However, ksm pages were not processed by hwpoison in 2009 [1]. The main method of implementation: 1. Refactor add_to_kill() and add new add_to_kill_*() to better accommodate the handling of different types of pages. 2. Add collect_procs_ksm() to collect processes when the error hit an ksm page. 3. Add task_in_to_kill_list() to avoid duplicate addition of tsk to the to_kill list. 4. Try_to_unmap ksm page (already supported). 5. Handle related processes such as sending SIGBUS. Tested with poisoning to ksm page from 1) different process 2) one process and with/without memory_failure_early_kill set, the processes are killed as expected with the patchset. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ commit/?h=01e00f880ca700376e1845cf7a2524ebe68e47d6 This patch (of 2): The page_address_in_vma() is used to find the user virtual address of page in add_to_kill(), but it doesn't support ksm due to the ksm page->index unusable, add an ksm_addr as parameter to add_to_kill(), let's the caller to pass it, also rename the function to __add_to_kill(), and adding add_to_kill_anon_file() for handling anonymous pages and file pages, adding add_to_kill_fsdax() for handling fsdax pages. Link: https://lkml.kernel.org/r/20230414021741.2597273-1-xialonglong1@huawei.com Link: https://lkml.kernel.org/r/20230414021741.2597273-2-xialonglong1@huawei.com Signed-off-by: Longlong Xia Tested-by: Naoya Horiguchi Reviewed-by: Kefeng Wang Cc: Kefeng Wang Cc: Miaohe Lin Cc: Nanyong Sun Signed-off-by: Andrew Morton

mm: memory-failure: Move memory failure sysctls to its own file

2023-04-13T18:49:35+00:00

The sysctl_memory_failure_early_kill and memory_failure_recovery are only used in memory-failure.c, move them to its own file. Acked-by: Naoya Horiguchi Signed-off-by: Kefeng Wang [mcgrof: fix by adding empty ctl entry, this caused a crash] Signed-off-by: Luis Chamberlain

mm: memory-failure: directly use IS_ENABLED(CONFIG_HWPOISON_INJECT)

2023-03-28T23:20:17+00:00

It's more clear and simple to just use IS_ENABLED(CONFIG_HWPOISON_INJECT) to check whether or not to enable HWPoison injector module instead of CONFIG_HWPOISON_INJECT/CONFIG_HWPOISON_INJECT_MODULE. Link: https://lkml.kernel.org/r/20230313053929.84607-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Reviewed-by: David Hildenbrand Acked-by: Naoya Horiguchi Cc: Miaohe Lin Signed-off-by: Andrew Morton