Hugh Dickins f2b277c4d1 memfd: fix F_SEAL_WRITE after shmem huge page allocated ... Wangyong reports: after enabling tmpfs filesystem to support transparent hugepage with the following command: echo always > /sys/kernel/mm/transparent_hugepage/shmem_enabled the docker program tries to add F_SEAL_WRITE through the following command, but it fails unexpectedly with errno EBUSY: fcntl(5, F_ADD_SEALS, F_SEAL_WRITE) = -1. That is because memfd_tag_pins() and memfd_wait_for_pins() were never updated for shmem huge pages: checking page_mapcount() against page_count() is hopeless on THP subpages - they need to check total_mapcount() against page_count() on THP heads only. Make memfd_tag_pins() (compared > 1) as strict as memfd_wait_for_pins() (compared != 1): either can be justified, but given the non-atomic total_mapcount() calculation, it is better now to be strict. Bear in mind that total_mapcount() itself scans all of the THP subpages, when choosing to take an XA_CHECK_SCHED latency break. Also fix the unlikely xa_is_value() case in memfd_wait_for_pins(): if a page has been swapped out since memfd_tag_pins(), then its refcount must have fallen, and so it can safely be untagged. Link: https://lkml.kernel.org/r/a4f79248-df75-2c8c-3df-ba3317ccb5da@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Zeal Robot <zealci@zte.com.cn> Reported-by: wangyong <wang.yong12@zte.com.cn> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: CGEL ZTE <cgel.zte@gmail.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Song Liu <songliubraving@fb.com> Cc: Yang Yang <yang.yang29@zte.com.cn> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2022-03-05 11:08:32 -08:00
..
damon
kasan
kfence
backing-dev.c
balloon_compaction.c
bootmem_info.c
cma.c
cma.h
cma_debug.c
cma_sysfs.c
compaction.c
debug.c
debug_page_ref.c
debug_vm_pgtable.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
folio-compat.c
frontswap.c
gup.c
gup_test.c
gup_test.h
highmem.c
hmm.c
huge_memory.c
hugetlb.c
hugetlb_cgroup.c
hugetlb_vmemmap.c
hugetlb_vmemmap.h
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
io-mapping.c
ioremap.c
Kconfig
Kconfig.debug
khugepaged.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c	mm: fix use-after-free when anon vma name is used after vma is freed	2022-03-05 11:08:32 -08:00
Makefile
mapping_dirty_helpers.c
memblock.c
memcontrol.c
memfd.c	memfd: fix F_SEAL_WRITE after shmem huge page allocated	2022-03-05 11:08:32 -08:00
memory-failure.c
memory.c
memory_hotplug.c
mempolicy.c	mm: refactor vm_area_struct::anon_vma_name usage code	2022-03-05 11:08:32 -08:00
mempool.c
memremap.c
memtest.c
migrate.c
mincore.c
mlock.c	mm: refactor vm_area_struct::anon_vma_name usage code	2022-03-05 11:08:32 -08:00
mm_init.c
mmap.c	mm: refactor vm_area_struct::anon_vma_name usage code	2022-03-05 11:08:32 -08:00
mmap_lock.c
mmu_gather.c
mmu_notifier.c
mmzone.c
mprotect.c	mm: refactor vm_area_struct::anon_vma_name usage code	2022-03-05 11:08:32 -08:00
mremap.c
msync.c
nommu.c
oom_kill.c
page-writeback.c
page_alloc.c
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c
page_vma_mapped.c
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c
pgalloc-track.h
pgtable-generic.c
process_vm_access.c
ptdump.c
readahead.c
rmap.c
rodata_test.c
secretmem.c
shmem.c
shuffle.c
shuffle.h
slab.c
slab.h
slab_common.c
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap.c
swap_cgroup.c
swap_slots.c
swap_state.c
swapfile.c
truncate.c
usercopy.c
userfaultfd.c
util.c
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c
vmstat.c
workingset.c
z3fold.c
zbud.c
zpool.c
zsmalloc.c
zswap.c