WSL2-Linux-Kernel/mm
Jean-Philippe Brucker 682d3a98ab mm/mmu_notifier: use hlist_add_head_rcu()
[ Upstream commit 543bdb2d82 ]

Make mmu_notifier_register() safer by issuing a memory barrier before
registering a new notifier.  This fixes a theoretical bug on weakly
ordered CPUs.  For example, take this simplified use of notifiers by a
driver:

	my_struct->mn.ops = &my_ops; /* (1) */
	mmu_notifier_register(&my_struct->mn, mm)
		...
		hlist_add_head(&mn->hlist, &mm->mmu_notifiers); /* (2) */
		...

Once mmu_notifier_register() releases the mm locks, another thread can
invalidate a range:

	mmu_notifier_invalidate_range()
		...
		hlist_for_each_entry_rcu(mn, &mm->mmu_notifiers, hlist) {
			if (mn->ops->invalidate_range)

The read side relies on the data dependency between mn and ops to ensure
that the pointer is properly initialized.  But the write side doesn't have
any dependency between (1) and (2), so they could be reordered and the
readers could dereference an invalid mn->ops.  mmu_notifier_register()
does take all the mm locks before adding to the hlist, but those have
acquire semantics which isn't sufficient.

By calling hlist_add_head_rcu() instead of hlist_add_head() we update the
hlist using a store-release, ensuring that readers see prior
initialization of my_struct.  This situation is better illustated by
litmus test MP+onceassign+derefonce.

Link: http://lkml.kernel.org/r/20190502133532.24981-1-jean-philippe.brucker@arm.com
Fixes: cddb8a5c14 ("mmu-notifiers: core")
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31 07:28:56 +02:00
..
kasan kasan: fix shadow_size calculation error in kasan_module_alloc 2018-08-24 13:09:12 +02:00
Kconfig mm/hmm: select mmu notifier when selecting HMM 2019-06-15 11:54:51 +02:00
Kconfig.debug kmemcheck: rip it out 2018-02-22 15:42:24 +01:00
Makefile kmemcheck: rip it out 2018-02-22 15:42:24 +01:00
backing-dev.c writeback: synchronize sync(2) against cgroup writeback membership switches 2019-03-05 17:58:01 +01:00
balloon_compaction.c virtio_balloon: fix deadlock on OOM 2018-10-13 09:27:30 +02:00
bootmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cleancache.c fs: switch ->s_uuid to uuid_t 2017-06-05 16:59:12 +02:00
cma.c mm/cma.c: fix the bitmap status to show failed allocation reason 2019-06-15 11:54:51 +02:00
cma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cma_debug.c mm/cma_debug.c: fix the break condition in cma_maxchunk_get() 2019-06-15 11:54:51 +02:00
compaction.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug.c mm: get rid of vmacache_flush_all() entirely 2018-09-19 22:43:48 +02:00
debug_page_ref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dmapool.c lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
early_ioremap.c mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep 2018-02-25 11:08:03 +01:00
fadvise.c mm/fadvise.c: fix signed overflow UBSAN complaint 2018-09-15 09:45:28 +02:00
failslab.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
filemap.c mm: add filemap_fdatawait_range_keep_errors() 2019-07-31 07:28:47 +02:00
frame_vector.c mm/frame_vector.c: release a semaphore in 'get_vaddr_frames()' 2018-03-03 10:24:21 +01:00
frontswap.c mm, frontswap: convert frontswap_enabled to static key 2016-07-26 16:19:19 -07:00
gup.c mm/gup.c: remove some BUG_ONs from get_gate_page() 2019-07-31 07:28:56 +02:00
highmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hmm.c mm, hmm: mark hmm_devmem_{add, add_resource} EXPORT_SYMBOL_GPL 2019-01-13 10:01:02 +01:00
huge_memory.c mm/huge_memory: fix lockdep complaint on 32-bit i_size_read() 2018-12-05 19:41:08 +01:00
hugetlb.c hugetlbfs: on restore reserve error path retain subpool reservation 2019-06-15 11:54:51 +02:00
hugetlb_cgroup.c mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size 2016-05-20 17:58:30 -07:00
hwpoison-inject.c mm: hwpoison: call shake_page() unconditionally 2017-05-03 15:52:12 -07:00
init-mm.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
internal.h mm, oom: do not rely on TIF_MEMDIE for memory reserves access 2017-09-06 17:27:30 -07:00
interval_tree.c lib/interval_tree: fast overlap detection 2017-09-08 18:26:49 -07:00
khugepaged.c coredump: fix race condition between collapse_huge_page() and core dumping 2019-06-22 08:16:19 +02:00
kmemleak-test.c
kmemleak.c mm/kmemleak.c: fix check for softirq context 2019-07-31 07:28:55 +02:00
ksm.c mm/ksm.c: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm() 2018-07-03 11:25:03 +02:00
list_lru.c mm/list_lru.c: fix memory leak in __memcg_init_list_lru_node 2019-06-19 08:20:54 +02:00
maccess.c x86: remove more uaccess_32.h complexity 2016-05-22 17:21:27 -07:00
madvise.c mm: madvise(MADV_DODUMP): allow hugetlbfs pages 2018-10-10 08:54:22 +02:00
memblock.c Revert "mm: page_alloc: skip over regions of invalid pfns where possible" 2018-03-28 18:24:39 +02:00
memcontrol.c memcg: remove memcg_cgroup::id from IDR on mem_cgroup_css_alloc() failure 2018-09-05 09:26:32 +02:00
memory-failure.c mm: hwpoison: fix thp split handing in soft_offline_in_use_page() 2019-03-23 14:35:24 +01:00
memory.c mm/memory.c: fix modifying of page protection by insert_pfn() 2019-05-16 19:42:31 +02:00
memory_hotplug.c mm, memory_hotplug: test_pages_in_a_zone do not pass the end of zone 2019-03-13 14:03:18 -07:00
mempolicy.c mm/mempolicy.c: fix an incorrect rebind node in mpol_rebind_nodemask 2019-07-03 13:15:59 +02:00
mempool.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
memtest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
migrate.c mm/migrate.c: add missing flush_dcache_page for non-mapped page migrate 2019-04-03 06:25:20 +02:00
mincore.c mm/mincore.c: make mincore() more conservative 2019-05-21 18:50:16 +02:00
mlock.c mm/mlock.c: change count_mm_mlocked_page_nr return type 2019-07-10 09:54:36 +02:00
mm_init.c
mmap.c coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping 2019-04-27 09:35:37 +02:00
mmu_context.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
mmu_notifier.c mm/mmu_notifier: use hlist_add_head_rcu() 2019-07-31 07:28:56 +02:00
mmzone.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mprotect.c x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings 2018-08-15 18:12:51 +02:00
mremap.c mremap: properly flush TLB before releasing the page 2018-10-20 09:48:53 +02:00
msync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nobootmem.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nommu.c Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
oom_kill.c mm, oom: fix use-after-free in oom_kill_process 2019-02-06 17:31:36 +01:00
page-writeback.c mm/page-writeback.c: don't break integrity writeback on ->writepage() error 2019-01-26 09:37:06 +01:00
page_alloc.c mem-hotplug: fix node spanned pages when we have a node with only ZONE_MOVABLE 2019-06-15 11:54:51 +02:00
page_counter.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_ext.c mm/page_ext.c: fix an imbalance with kmemleak 2019-04-05 22:31:27 +02:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-07-03 13:15:59 +02:00
page_io.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_isolation.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
page_owner.c mm/page_owner: fix recursion bug after changing skip entries 2018-05-30 07:52:21 +02:00
page_poison.c page_poison: play nicely with KASAN 2019-04-05 22:31:28 +02:00
page_vma_mapped.c mm/rmap: map_pte() was not handling private ZONE_DEVICE page properly 2018-11-13 11:15:08 -08:00
pagewalk.c mm/pagewalk.c: report holes in hugetlb ranges 2017-11-24 08:37:04 +01:00
percpu-internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
percpu-km.c percpu: convert spin_lock_irq to spin_lock_irqsave. 2019-02-12 19:46:05 +01:00
percpu-stats.c percpu: fix starting offset for chunk statistics traversal 2017-09-27 14:45:57 -07:00
percpu-vm.c percpu: add __GFP_NORETRY semantics to the percpu balancing path 2018-04-08 14:26:29 +02:00
percpu.c percpu: do not search past bitmap when allocating an area 2019-06-15 11:54:59 +02:00
pgtable-generic.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
process_vm_access.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h> 2017-03-02 08:42:28 +01:00
quicklist.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
readahead.c readahead: stricter check for bdi io_pages 2018-09-09 19:55:53 +02:00
rmap.c mm: migration: fix migration of huge PMD shared pages 2018-10-13 09:27:22 +02:00
rodata_test.c mm: fix RODATA_TEST failure "rodata_test: test data was not read only" 2017-10-03 17:54:24 -07:00
shmem.c tmpfs: fix uninitialized return value in shmem_link 2019-03-23 14:35:17 +01:00
slab.c mm/slab.c: fix an infinite loop in leaks_show() 2019-06-15 11:54:51 +02:00
slab.h kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2018-02-22 15:42:23 +01:00
slab_common.c mm: don't warn about large allocations for slab 2018-12-01 09:42:51 +01:00
slob.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
slub.c slub: make ->cpu_partial unsigned int 2018-10-03 17:00:55 -07:00
sparse-vmemmap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sparse.c mm: sections are not offlined during memory hotremove 2018-05-16 10:10:27 +02:00
swap.c mm: avoid marking swap cached page as lazyfree 2017-10-03 17:54:24 -07:00
swap_cgroup.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_slots.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swap_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swapfile.c mm/swap: use nr_node_ids for avail_lists in swap_info_struct 2019-01-26 09:37:06 +01:00
truncate.c mm: cleancache: fix corruption on missed inode invalidation 2018-12-08 13:03:40 +01:00
usercopy.c mm/usercopy: Drop extra is_vmalloc_or_module() check 2017-04-05 12:30:18 -07:00
userfaultfd.c hugetlb: use same fault hash key for shared and private mappings 2019-05-31 06:47:12 -07:00
util.c mm: page_mapped: don't assume compound page is huge or THP 2019-01-16 22:07:11 +01:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-19 22:43:48 +02:00
vmalloc.c mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512! 2019-04-05 22:31:27 +02:00
vmpressure.c mm, vmpressure: pass-through notification support 2017-07-10 16:32:31 -07:00
vmscan.c mm: vmscan: scan anonymous pages on file refaults 2019-07-31 07:28:48 +02:00
vmstat.c mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n 2019-04-27 09:35:41 +02:00
workingset.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
z3fold.c z3fold: fix possible reclaim races 2018-12-01 09:42:54 +01:00
zbud.c
zpool.c
zsmalloc.c zsmalloc: calling zs_map_object() from irq is a bug 2017-12-14 09:53:10 +01:00
zswap.c zswap: re-check zswap_is_full() after do zswap_shrink() 2018-09-05 09:26:30 +02:00