David Herrmann 05f65b5c70 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. 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>		2014-08-08 15:57:31 -07:00
..
backing-dev.c	arch: Mass conversion of smp_mb__*()	2014-04-18 14:20:48 +02:00
balloon_compaction.c	mm: print more details for bad_page()	2014-01-23 16:36:50 -08:00
bootmem.c	mm/bootmem.c: remove unused local `map'	2013-11-13 12:09:09 +09:00
cleancache.c	mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE	2014-01-23 16:36:50 -08:00
cma.c	mm, CMA: clean-up log message	2014-08-06 18:01:16 -07:00
compaction.c	mm, compaction: properly signal and act upon lock and need_sched() contention	2014-06-04 16:54:11 -07:00
debug-pagealloc.c
dmapool.c	mm/dmapool.c: reuse devres_release() to free resources	2014-06-04 16:54:08 -07:00
early_ioremap.c	mm: create generic early_ioremap() support	2014-04-07 16:36:15 -07:00
fadvise.c
failslab.c
filemap_xip.c	seqcount: Add lockdep functionality to seqcount/seqlock structures	2013-11-06 12:40:26 +01:00
filemap.c	mm: memcontrol: rewrite uncharge API	2014-08-08 15:57:17 -07:00
fremap.c	mm: mark remap_file_pages() syscall as deprecated	2014-06-06 16:08:17 -07:00
frontswap.c	swap: change swap_list_head to plist, add swap_avail_head	2014-06-04 16:54:07 -07:00
gup.c	mm: describe mmap_sem rules for __lock_page_or_retry() and callers	2014-08-06 18:01:20 -07:00
highmem.c	mm/highmem: make kmap cache coloring aware	2014-08-06 18:01:22 -07:00
huge_memory.c	mm: memcontrol: rewrite charge API	2014-08-08 15:57:17 -07:00
hugetlb_cgroup.c	cgroup: replace cgroup_add_cftypes() with cgroup_add_legacy_cftypes()	2014-07-15 11:05:09 -04:00
hugetlb.c	mm: fix potential infinite loop in dissolve_free_huge_pages()	2014-08-06 18:01:21 -07:00
hwpoison-inject.c	mm/hwpoison-inject.c: remove unnecessary null test before debugfs_remove_recursive	2014-08-06 18:01:19 -07:00
init-mm.c
internal.h	mm/internal.h: use nth_page	2014-08-06 18:01:16 -07:00
interval_tree.c
iov_iter.c	bio_vec-backed iov_iter	2014-05-06 17:39:45 -04:00
Kconfig	mm/zpool: update zswap to use zpool	2014-08-06 18:01:23 -07:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c	mm/kmemleak-test.c: use pr_fmt for logging	2014-06-06 16:08:18 -07:00
kmemleak.c	mm: introduce kmemleak_update_trace()	2014-06-06 16:08:17 -07:00
ksm.c	sched: Remove proliferation of wait_on_bit() action functions	2014-07-16 15:10:39 +02:00
list_lru.c	mm: keep page cache radix tree nodes in check	2014-04-03 16:21:01 -07:00
maccess.c
madvise.c	mm: update the description for madvise_remove	2014-08-06 18:01:18 -07:00
Makefile	mm/zpool: implement common zpool api to zbud/zsmalloc	2014-08-06 18:01:23 -07:00
memblock.c	mm/memblock.c: call kmemleak directly from memblock_(alloc|free)	2014-06-06 16:08:17 -07:00
memcontrol.c	mm: memcontrol: avoid charge statistics churn during page migration	2014-08-08 15:57:18 -07:00
memory_hotplug.c	memory-hotplug: add zone_for_memory() for selecting zone for new memory	2014-08-06 18:01:21 -07:00
memory-failure.c	hwpoison: fix race with changing page during offlining	2014-08-06 18:01:19 -07:00
memory.c	arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area	2014-08-08 15:57:27 -07:00
mempolicy.c	Merge branch 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2014-07-10 11:38:23 -07:00
mempool.c	mm/mempool.c: update the kmemleak stack trace for mempool allocations	2014-06-06 16:08:17 -07:00
migrate.c	mm: memcontrol: rewrite uncharge API	2014-08-08 15:57:17 -07:00
mincore.c	mm + fs: prepare for non-page entries in page cache radix trees	2014-04-03 16:21:00 -07:00
mlock.c	mm: describe mmap_sem rules for __lock_page_or_retry() and callers	2014-08-06 18:01:20 -07:00
mm_init.c	mm: bring back /sys/kernel/mm	2014-01-27 21:02:39 -08:00
mmap.c	mm: allow drivers to prevent new writable mappings	2014-08-08 15:57:31 -07:00
mmu_context.c	sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm	2014-02-21 08:50:17 +01:00
mmu_notifier.c	mmu_notifier: add call_srcu and sync function for listener to delay call and sync	2014-08-06 18:01:22 -07:00
mmzone.c	mm: numa: Change page last {nid,pid} into {cpu,pid}	2013-10-09 14:47:45 +02:00
mprotect.c	mm: move mmu notifier call from change_protection to change_pmd_range	2014-04-07 16:35:50 -07:00
mremap.c	mm, thp: close race between mremap() and split_huge_page()	2014-05-11 17:55:48 +09:00
msync.c	msync: fix incorrect fstart calculation	2014-07-03 09:21:53 -07:00
nobootmem.c	mm/memblock.c: call kmemleak directly from memblock_(alloc|free)	2014-06-06 16:08:17 -07:00
nommu.c	arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area	2014-08-08 15:57:27 -07:00
oom_kill.c	mm, oom: remove unnecessary exit_state check	2014-08-06 18:01:21 -07:00
page_alloc.c	mm, thp: restructure thp avoidance of light synchronous migration	2014-08-06 18:01:21 -07:00
page_cgroup.c	mm/page_cgroup.c: mark functions as static	2014-04-03 16:21:02 -07:00
page_io.c	fix __swap_writepage() compile failure on old gcc versions	2014-06-14 19:30:48 -05:00
page_isolation.c	mm: memory-hotplug: enable memory hotplug to handle hugepage	2013-09-11 15:57:48 -07:00
page-writeback.c	mm, writeback: prevent race when calculating dirty limits	2014-08-06 18:01:21 -07:00
pagewalk.c	mm/pagewalk.c: fix walk_page_range() access of wrong PTEs	2013-10-30 14:27:03 -07:00
percpu-km.c
percpu-vm.c
percpu.c	percpu: Use ALIGN macro instead of hand coding alignment calculation	2014-06-19 11:00:27 -04:00
pgtable-generic.c	mm: fix TLB flush race between migration, and change_protection_range	2013-12-18 19:04:51 -08:00
process_vm_access.c	start adding the tag to iov_iter	2014-05-06 17:32:49 -04:00
quicklist.c
readahead.c	mm/readahead.c: remove unused file_ra_state from count_history_pages	2014-08-06 18:01:15 -07:00
rmap.c	mm: memcontrol: rewrite uncharge API	2014-08-08 15:57:17 -07:00
shmem.c	shm: wait for pins to be released when sealing	2014-08-08 15:57:31 -07:00
slab_common.c	mm: move slab related stuff from util.c to slab_common.c	2014-08-06 18:01:15 -07:00
slab.c	Revert "slab: remove BAD_ALIEN_MAGIC"	2014-08-08 15:57:17 -07:00
slab.h	slab: convert last use of __FUNCTION__ to __func__	2014-08-06 18:01:15 -07:00
slob.c	slab: get_online_mems for kmem_cache_{create,destroy,shrink}	2014-06-04 16:53:59 -07:00
slub.c	slub: remove kmemcg id from create_unique_id	2014-08-06 18:01:21 -07:00
sparse-vmemmap.c	mm/sparse: use memblock apis for early memory allocations	2014-01-21 16:19:47 -08:00
sparse.c	mm: use macros from compiler.h instead of __attribute__((...))	2014-04-07 16:35:54 -07:00
swap_state.c	mm: allow drivers to prevent new writable mappings	2014-08-08 15:57:31 -07:00
swap.c	mm: memcontrol: use page lists for uncharge batching	2014-08-08 15:57:18 -07:00
swapfile.c	mm: memcontrol: rewrite uncharge API	2014-08-08 15:57:17 -07:00
truncate.c	mm: memcontrol: rewrite uncharge API	2014-08-08 15:57:17 -07:00
util.c	vm_is_stack: use for_each_thread() rather then buggy while_each_thread()	2014-08-08 15:57:17 -07:00
vmacache.c	mm,vmacache: optimize overflow system-wide flushing	2014-06-04 16:53:57 -07:00
vmalloc.c	mm/vmalloc.c: clean up map_vm_area third argument	2014-08-06 18:01:19 -07:00
vmpressure.c	arm, pm, vmpressure: add missing slab.h includes	2014-02-03 13:24:01 -05:00
vmscan.c	mm: memcontrol: use page lists for uncharge batching	2014-08-08 15:57:18 -07:00
vmstat.c	mm: vmscan: only update per-cpu thresholds for online CPU	2014-08-06 18:01:20 -07:00
workingset.c	mm: keep page cache radix tree nodes in check	2014-04-03 16:21:01 -07:00
zbud.c	mm/zpool: zbud/zsmalloc implement zpool	2014-08-06 18:01:23 -07:00
zpool.c	mm/zpool: implement common zpool api to zbud/zsmalloc	2014-08-06 18:01:23 -07:00
zsmalloc.c	mm/zpool: zbud/zsmalloc implement zpool	2014-08-06 18:01:23 -07:00
zswap.c	mm/zswap.c: add __init to zswap_entry_cache_destroy()	2014-08-08 15:57:18 -07:00