Nadav Amit a759a909d4 userfaultfd: change mmap_changing to atomic ... Patch series "userfaultfd: minor bug fixes". Three unrelated bug fixes. The first two addresses possible issues (not too theoretical ones), but I did not encounter them in practice. The third patch addresses a test bug that causes the test to fail on my system. It has been sent before as part of a bigger RFC. This patch (of 3): mmap_changing is currently a boolean variable, which is set and cleared without any lock that protects against concurrent modifications. mmap_changing is supposed to mark whether userfaultfd page-faults handling should be retried since mappings are undergoing a change. However, concurrent calls, for instance to madvise(MADV_DONTNEED), might cause mmap_changing to be false, although the remove event was still not read (hence acknowledged) by the user. Change mmap_changing to atomic_t and increase/decrease appropriately. Add a debug assertion to see whether mmap_changing is negative. Link: https://lkml.kernel.org/r/20210808020724.1022515-1-namit@vmware.com Link: https://lkml.kernel.org/r/20210808020724.1022515-2-namit@vmware.com Fixes: df2cc96e77 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Signed-off-by: Nadav Amit <namit@vmware.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Peter Xu <peterx@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-09-03 09:58:16 -07:00
..
kasan	mm/kasan: move kasan.fault to mm/kasan/report.c	2021-09-03 09:58:14 -07:00
kfence	kfence: skip all GFP_ZONEMASK allocations	2021-07-23 17:43:28 -07:00
backing-dev.c	writeback: fix bandwidth estimate for spiky workload	2021-09-03 09:58:10 -07:00
balloon_compaction.c	mm: fix typos in comments	2021-05-07 00:26:35 -07:00
bootmem_info.c	mm/bootmem_info.c: mark __init on register_page_bootmem_info_section	2021-09-03 09:58:14 -07:00
cleancache.c
cma_debug.c	mm/cma: change cma mutex to irq safe spinlock	2021-05-05 11:27:21 -07:00
cma_sysfs.c	mm: cma: support sysfs	2021-05-05 11:27:24 -07:00
cma.c	mm: use proper type for cma_[alloc|release]	2021-05-05 11:27:24 -07:00
cma.h	mm: cma: support sysfs	2021-05-05 11:27:24 -07:00
compaction.c	Merge branch 'akpm' (patches from Andrew)	2021-07-02 12:08:10 -07:00
debug_page_ref.c
debug_vm_pgtable.c	mm/debug_vm_pgtable: fix corrupted page flag	2021-09-03 09:58:10 -07:00
debug.c	mm/debug: factor PagePoisoned out of __dump_page	2021-06-29 10:53:53 -07:00
dmapool.c	mm/dmapool: use DEVICE_ATTR_RO macro	2021-06-29 10:53:52 -07:00
early_ioremap.c	mm/early_ioremap.c: use __func__ instead of function name	2021-02-26 09:41:02 -08:00
fadvise.c	mm, fadvise: improve the expensive remote LRU cache draining after FADV_DONTNEED	2020-10-13 18:38:29 -07:00
failslab.c
filemap.c	mm: remove irqsave/restore locking from contexts with irqs enabled	2021-09-03 09:58:10 -07:00
frontswap.c	mm/mempool: minor coding style tweaks	2021-05-05 11:27:27 -07:00
gup_test.c	selftests/vm: gup_test: test faulting in kernel, and verify pinnable pages	2021-05-05 11:27:26 -07:00
gup_test.h	selftests/vm: gup_test: fix test flag	2021-05-05 11:27:26 -07:00
gup.c	mm/gup: remove try_get_page(), call try_get_compound_head() directly	2021-09-03 09:58:11 -07:00
highmem.c	mm: fix typos in comments	2021-05-07 00:26:35 -07:00
hmm.c	mm: device exclusive memory access	2021-07-01 11:06:03 -07:00
huge_memory.c	mm,do_huge_pmd_numa_page: remove unnecessary TLB flushing code	2021-09-03 09:58:13 -07:00
hugetlb_cgroup.c	hugetlb: make free_huge_page irq safe	2021-05-05 11:27:22 -07:00
hugetlb_vmemmap.c	mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON	2021-06-30 20:47:26 -07:00
hugetlb_vmemmap.h	mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate	2021-06-30 20:47:25 -07:00
hugetlb.c	hugetlb: fix hugetlb cgroup refcounting during vma split	2021-09-03 09:58:16 -07:00
hwpoison-inject.c	mm: hwpoison: don't drop slab caches for offlining non-LRU page	2021-09-03 09:58:15 -07:00
init-mm.c	mm: add setup_initial_init_mm() helper	2021-07-08 11:48:21 -07:00
internal.h	mm: introduce memmap_alloc() to unify memory map allocation	2021-09-03 09:58:15 -07:00
interval_tree.c	mm/interval_tree: add comments to improve code readability	2021-04-30 11:20:38 -07:00
io-mapping.c	mm: add a io_mapping_map_user helper	2021-04-30 11:20:39 -07:00
ioremap.c	mm/ioremap: fix iomap_max_page_shift	2021-05-14 19:41:32 -07:00
Kconfig	mm: introduce memfd_secret system call to create "secret" memory areas	2021-07-08 11:48:21 -07:00
Kconfig.debug	mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO	2020-12-15 12:13:46 -08:00
khugepaged.c	huge tmpfs: SGP_NOALLOC to stop collapse_file() on race	2021-09-03 09:58:12 -07:00
kmemleak.c	kasan, kmemleak: reset tags when scanning block	2021-08-13 14:09:31 -10:00
ksm.c	mm/ksm: use vma_lookup() in find_mergeable_vma()	2021-06-29 10:53:52 -07:00
list_lru.c	mm: vmscan: consolidate shrinker_maps handling code	2021-05-05 11:27:23 -07:00
maccess.c	uaccess: add force_uaccess_{begin,end} helpers	2020-08-12 10:57:59 -07:00
madvise.c	mm/madvise: report SIGBUS as -EFAULT for MADV_POPULATE_(READ|WRITE)	2021-08-13 14:09:31 -10:00
Makefile	mm: introduce memfd_secret system call to create "secret" memory areas	2021-07-08 11:48:21 -07:00
mapping_dirty_helpers.c	mm/mapping_dirty_helpers: remove double Note in kerneldoc	2021-07-01 11:06:02 -07:00
memblock.c	memblock: stop poisoning raw allocations	2021-09-03 09:58:15 -07:00
memcontrol.c	memcg: make memcg->event_list_lock irqsafe	2021-09-03 09:58:13 -07:00
memfd.c	Reimplement RLIMIT_MEMLOCK on top of ucounts	2021-04-30 14:14:02 -05:00
memory_hotplug.c	mm/memory_hotplug: fix potential permanent lru cache disable	2021-08-25 12:25:12 -07:00
memory-failure.c	mm: fix panic caused by __page_handle_poison()	2021-09-03 09:58:16 -07:00
memory.c	mm: fix the deadlock in finish_fault()	2021-07-23 17:43:28 -07:00
mempolicy.c	mm/mempolicy: use unified 'nodes' for bind/interleave/prefer policies	2021-06-30 20:47:29 -07:00
mempool.c	kasan: use separate (un)poison implementation for integrated init	2021-06-04 19:32:21 +01:00
memremap.c	mm/memremap.c: fix improper SPDX comment style	2021-04-30 11:20:37 -07:00
memtest.c
migrate.c	mm/migrate: fix NR_ISOLATED corruption on 64-bit	2021-07-30 10:14:39 -07:00
mincore.c	inode: make init and permission helpers idmapped mount aware	2021-01-24 14:27:16 +01:00
mlock.c	mm: introduce memfd_secret system call to create "secret" memory areas	2021-07-08 11:48:21 -07:00
mm_init.c	include/linux/page-flags-layout.h: cleanups	2021-04-30 11:20:42 -07:00
mmap_lock.c	mm: mmap_lock: fix disabling preemption directly	2021-07-23 17:43:28 -07:00
mmap.c	remap_file_pages: Use vma_lookup() instead of find_vma()	2021-09-03 09:58:14 -07:00
mmu_gather.c	mm: eliminate "expecting prototype" kernel-doc warnings	2021-04-16 16:10:36 -07:00
mmu_notifier.c	mm/mmu_notifiers: ensure range_end() is paired with range_start()	2021-03-25 09:22:55 -07:00
mmzone.c	mm/lru: replace pgdat lru_lock with lruvec lock	2020-12-15 14:48:04 -08:00
mprotect.c	mm: device exclusive memory access	2021-07-01 11:06:03 -07:00
mremap.c	mm/mremap: fix memory account on do_munmap() failure	2021-09-03 09:58:14 -07:00
msync.c	mm/msync: exit early when the flags is an MS_ASYNC and start < vm_start	2021-04-30 11:20:37 -07:00
nommu.c	mm/nommu: unexport do_munmap()	2021-06-30 20:47:30 -07:00
oom_kill.c	Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu	2021-07-04 12:58:33 -07:00
page_alloc.c	mm/page_alloc.c: use in_task()	2021-09-03 09:58:15 -07:00
page_counter.c	mm: page_counter: mitigate consequences of a page_counter underflow	2021-04-30 11:20:38 -07:00
page_ext.c	mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM	2021-06-29 10:53:55 -07:00
page_idle.c	mm: page_idle_get_page() does not need lru_lock	2020-12-15 14:48:03 -08:00
page_io.c	swap: fix swapfile read/write offset	2021-03-02 17:25:46 -07:00
page_isolation.c	mm/page_isolation: tracing: trace all test_pages_isolated failures	2021-09-03 09:58:15 -07:00
page_owner.c	mm/page_owner: constify dump_page_owner	2021-06-29 10:53:53 -07:00
page_poison.c	mm: page_poison: print page info when corruption is caught	2021-04-30 11:20:36 -07:00
page_reporting.c	mm/page_reporting: allow driver to specify reporting order	2021-06-29 10:53:47 -07:00
page_reporting.h	mm/page_reporting: export reporting order as module parameter	2021-06-29 10:53:47 -07:00
page_vma_mapped.c	mm: device exclusive memory access	2021-07-01 11:06:03 -07:00
page-writeback.c	writeback: use READ_ONCE for unlocked reads of writeback stats	2021-09-03 09:58:10 -07:00
pagewalk.c	mm: pagewalk: fix walk for hugepage tables	2021-06-29 10:53:49 -07:00
percpu-internal.h	Merge branch 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu	2021-07-01 17:17:24 -07:00
percpu-km.c	percpu: flush tlb in pcpu_reclaim_populated()	2021-07-04 18:30:17 +00:00
percpu-stats.c	percpu: rework memcg accounting	2021-06-05 20:43:15 +00:00
percpu-vm.c	percpu: flush tlb in pcpu_reclaim_populated()	2021-07-04 18:30:17 +00:00
percpu.c	percpu: flush tlb in pcpu_reclaim_populated()	2021-07-04 18:30:17 +00:00
pgalloc-track.h	mm: fix typos in comments	2021-05-07 00:26:35 -07:00
pgtable-generic.c	mm/thp: fix __split_huge_pmd_locked() on shmem migration entry	2021-06-16 09:24:42 -07:00
process_vm_access.c	mm/process_vm_access.c: remove duplicate include	2021-05-05 11:27:27 -07:00
ptdump.c	mm: ptdump: fix build failure	2021-04-16 16:10:37 -07:00
readahead.c	mm: Implement readahead_control pageset expansion	2021-04-23 10:14:29 +01:00
rmap.c	mm/rmap: fix munlocking Anon THP with mlocked ptes	2021-07-12 11:30:56 -07:00
rodata_test.c	mm/rodata_test.c: fix missing function declaration	2020-08-21 09:52:53 -07:00
secretmem.c	mm/secretmem: wire up ->set_page_dirty	2021-07-23 17:43:28 -07:00
shmem.c	shmem: shmem_writepage() split unlikely i915 THP	2021-09-03 09:58:12 -07:00
shuffle.c	mm: eliminate "expecting prototype" kernel-doc warnings	2021-04-16 16:10:36 -07:00
shuffle.h	mm/shuffle: fix section mismatch warning	2021-05-22 15:09:07 -10:00
slab_common.c	Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu	2021-07-04 12:58:33 -07:00
slab.c	mm: fix typos in comments	2021-05-07 00:26:35 -07:00
slab.h	mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook()	2021-07-30 10:14:39 -07:00
slob.c	mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernels	2021-03-08 14:18:46 -08:00
slub.c	mm: slub: fix slub_debug disabling for list of slabs	2021-08-13 14:09:31 -10:00
sparse-vmemmap.c	mm: sparsemem: split the huge PMD mapping of vmemmap pages	2021-06-30 20:47:26 -07:00
sparse.c	mm: introduce memmap_alloc() to unify memory map allocation	2021-09-03 09:58:15 -07:00
swap_cgroup.c
swap_slots.c	mm/swap_slots.c: delete meaningless forward declarations	2021-06-29 10:53:49 -07:00
swap_state.c	Revert "mm: swap: check if swap backing device is congested or not"	2021-08-20 11:31:42 -07:00
swap.c	mm: delete unused get_kernel_page()	2021-09-03 09:58:11 -07:00
swapfile.c	mm, memcg: inline swap-related functions to improve disabled memcg config	2021-09-03 09:58:12 -07:00
truncate.c	fs: inode: count invalidated shadow pages in pginodesteal	2021-09-03 09:58:10 -07:00
usercopy.c	mm/usercopy.c: delete duplicated word	2020-08-12 10:57:58 -07:00
userfaultfd.c	userfaultfd: change mmap_changing to atomic	2021-09-03 09:58:16 -07:00
util.c	mm: Make copy_huge_page() always available	2021-07-12 11:30:56 -07:00
vmacache.c
vmalloc.c	mm/vmalloc: fix wrong behavior in vread	2021-09-03 09:58:14 -07:00
vmpressure.c	mm, memcg: add mem_cgroup_disabled checks in vmpressure and swap-related functions	2021-09-03 09:58:12 -07:00
vmscan.c	memcg: infrastructure to flush memcg stats	2021-09-03 09:58:12 -07:00
vmstat.c	mm/vmstat: inline NUMA event counter updates	2021-06-29 10:53:54 -07:00
workingset.c	mm: workingset: define macro WORKINGSET_SHIFT	2021-06-30 20:47:28 -07:00
z3fold.c	mm/z3fold: add kerneldoc fields for z3fold_pool	2021-07-01 11:06:03 -07:00
zbud.c	mm/zbud: add kerneldoc fields for zbud_pool	2021-07-01 11:06:03 -07:00
zpool.c	mm: fix typos in comments	2021-05-07 00:26:35 -07:00
zsmalloc.c	mm/zsmalloc.c: improve readability for async_free_zspage()	2021-07-01 11:06:02 -07:00
zswap.c	mm/zswap.c: fix two bugs in zswap_writeback_entry()	2021-06-30 20:47:31 -07:00