kernel_optimize_test/mm
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
balloon_compaction.c
bootmem.c
cleancache.c
cma.c mm, CMA: clean-up log message 2014-08-06 18:01:16 -07:00
compaction.c
debug-pagealloc.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap_xip.c
filemap.c mm: memcontrol: rewrite uncharge API 2014-08-08 15:57:17 -07:00
fremap.c
frontswap.c
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
Kconfig mm/zpool: update zswap to use zpool 2014-08-06 18:01:23 -07:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
list_lru.c
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
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
migrate.c mm: memcontrol: rewrite uncharge API 2014-08-08 15:57:17 -07:00
mincore.c
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
mmap.c mm: allow drivers to prevent new writable mappings 2014-08-08 15:57:31 -07:00
mmu_context.c
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
mprotect.c
mremap.c
msync.c msync: fix incorrect fstart calculation 2014-07-03 09:21:53 -07:00
nobootmem.c
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
page_io.c fix __swap_writepage() compile failure on old gcc versions 2014-06-14 19:30:48 -05:00
page_isolation.c
page-writeback.c mm, writeback: prevent race when calculating dirty limits 2014-08-06 18:01:21 -07:00
pagewalk.c
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
process_vm_access.c
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
slub.c slub: remove kmemcg id from create_unique_id 2014-08-06 18:01:21 -07:00
sparse-vmemmap.c
sparse.c
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
vmalloc.c mm/vmalloc.c: clean up map_vm_area third argument 2014-08-06 18:01:19 -07:00
vmpressure.c
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
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