David Herrmann 4a58329a3e shm: wait for pins to be released when sealing ... If we set SEAL_WRITE on a file, we must make sure there cannot be any ongoing write-operations on the file. For write() calls, we simply lock the inode mutex, for mmap() we simply verify there're no writable mappings. However, there might be pages pinned by AIO, Direct-IO and similar operations via GUP. We must make sure those do not write to the memfd file after we set SEAL_WRITE. As there is no way to notify GUP users to drop pages or to wait for them to be done, we implement the wait ourself: When setting SEAL_WRITE, we check all pages for their ref-count. If it's bigger than 1, we know there's some user of the page. We then mark the page and wait for up to 150ms for those ref-counts to be dropped. If the ref-counts are not dropped in time, we refuse the seal operation. Change-Id: I964c29a82f2a9a1077647b29b2073c9ef4e0a05a Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2020-12-07 22:15:24 +03:00
..
backing-dev.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
bootmem.c	mm: sparse: fix usemap allocation above node descriptor section	2016-10-29 23:12:12 +08:00
bounce.c	mm: remove the second argument of k[un]map_atomic()	2012-03-20 21:48:27 +08:00
cleancache.c
compaction.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
debug-pagealloc.c
dmapool.c	mm: dmapool: use provided gfp flags for all dma_alloc_coherent() calls	2012-12-17 10:37:44 -08:00
fadvise.c	mm/fadvise.c: drain all pagevecs if POSIX_FADV_DONTNEED fails to discard all pages	2013-02-28 06:59:01 -08:00
failslab.c
filemap.c	lib/radix-tree.c: make radix_tree_node_alloc() work correctly within interrupt	2020-12-07 21:02:05 +03:00
filemap_xip.c	mm: kill vma flag VM_CAN_NONLINEAR	2020-11-29 16:11:40 +03:00
fremap.c	mm: kill vma flag VM_CAN_NONLINEAR	2020-11-29 16:11:40 +03:00
highmem.c	mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem address	2014-06-11 12:04:22 -07:00
huge_memory.c	mm, thp: fix collapsing of hugepages on madvise	2015-02-02 17:05:07 +08:00
hugetlb.c	Fix incomplete backport of commit 0f792cf949a0	2016-10-26 23:15:44 +08:00
hwpoison-inject.c
init-mm.c
internal.h	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
Kconfig	BACKPORT: mm/zsmalloc: add statistics support	2018-01-01 21:27:09 +03:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c	mm: kmemleak: allow safe memory scanning during kmemleak disabling	2015-10-22 09:20:06 +08:00
ksm.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
maccess.c
madvise.c	mm/fs: route MADV_REMOVE to FALLOC_FL_PUNCH_HOLE	2020-12-07 21:00:58 +03:00
Makefile	BACKPORT: mm/zpool: implement common zpool api to zbud/zsmalloc	2018-01-01 21:27:00 +03:00
memblock.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
memcontrol.c	shmem: replace page if mapping excludes its zone	2020-12-07 20:57:06 +03:00
memory-failure.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
memory.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
memory_hotplug.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
mempolicy.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
mempool.c
migrate.c	BACKPORT: Sanitize 'move_pages()' permission checks	2018-01-13 17:13:40 +03:00
mincore.c	swap: make each swap partition have one address_space	2018-01-01 22:02:05 +03:00
mlock.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
mm_init.c
mmap.c	mm: allow drivers to prevent new writable mappings	2020-12-07 21:08:09 +03:00
mmu_context.c	mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat()	2012-03-21 17:54:59 -07:00
mmu_notifier.c	mm: mmu_notifier: re-fix freed page still mapped in secondary MMU	2013-06-07 12:49:25 -07:00
mmzone.c
mprotect.c	mm: add a field to store names for private anonymous memory	2013-10-11 10:02:06 -07:00
mremap.c	mm: collapse security_vm_enough_memory() variants into a single function	2012-02-14 10:45:39 +11:00
msync.c
nobootmem.c	memblock: free allocated memblock_reserved_regions later	2012-07-16 09:04:45 -07:00
nommu.c	mm: kill vma flag VM_CAN_NONLINEAR	2020-11-29 16:11:40 +03:00
oom_kill.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
page-writeback.c	mm: fix calculation of dirtyable memory	2016-10-29 23:12:16 +08:00
page_alloc.c	mm/page_alloc.c: use '__paginginit' instead of '__init'	2017-12-27 17:13:39 +03:00
page_cgroup.c	cgroup/kmemleak: add kmemleak_free() for cgroup deallocations.	2015-02-02 17:05:07 +08:00
page_io.c
page_isolation.c	mm: page_isolation: MIGRATE_CMA isolation functions added	2013-02-27 18:14:02 -08:00
pagewalk.c	mm/pagewalk.c: walk_page_range should avoid VM_PFNMAP areas	2013-06-07 12:49:28 -07:00
percpu-km.c
percpu-vm.c	percpu: perform tlb flush after pcpu_map_pages() failure	2014-12-01 18:02:23 +08:00
percpu.c	Revert "percpu: free percpu allocation info for uniprocessor system"	2015-02-02 17:04:38 +08:00
pgtable-generic.c	thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE	2012-03-21 17:55:02 -07:00
prio_tree.c
process_vm_access.c	Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys	2013-03-14 11:29:51 -07:00
quicklist.c
readahead.c	mm: change initial readahead window size calculation	2016-10-29 23:12:18 +08:00
rmap.c	mm: fix anon_vma->degree underflow in anon_vma endless growing prevention	2015-04-14 17:34:04 +08:00
shmem.c	shm: wait for pins to be released when sealing	2020-12-07 22:15:24 +03:00
slab.c	cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags	2014-12-01 18:02:38 +08:00
slob.c
slub.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
sparse-vmemmap.c
sparse.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
swap.c	swap: make each swap partition have one address_space	2018-01-01 22:02:05 +03:00
swap_state.c	mm: allow drivers to prevent new writable mappings	2020-12-07 21:08:09 +03:00
swapfile.c	vfs: make path_openat take a struct filename pointer	2018-12-07 22:28:48 +04:00
thrash.c
truncate.c	mm/fs: remove truncate_range	2020-12-07 20:57:30 +03:00
util.c	swap: make each swap partition have one address_space	2018-01-01 22:02:05 +03:00
vmalloc.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
vmscan.c	mm: new shrinker API	2020-11-29 16:11:30 +03:00
vmstat.c	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
zpool.c	BACKPORT: mm/zpool: add name argument to create zpool	2018-01-01 21:27:09 +03:00
zsmalloc.c	UPSTREAM: zsmalloc: fix a null pointer dereference in destroy_handle_cache()	2018-01-01 21:27:14 +03:00