Michel Lespinasse 4128997b5f mm: protect against concurrent vma expansion ... expand_stack() runs with a shared mmap_sem lock. Because of this, there could be multiple concurrent stack expansions in the same mm, which may cause problems in the vma gap update code. I propose to solve this by taking the mm->page_table_lock around such vma expansions, in order to avoid the concurrency issue. We only have to worry about concurrent expand_stack() calls here, since we hold a shared mmap_sem lock and all vma modificaitons other than expand_stack() are done under an exclusive mmap_sem lock. I previously tried to achieve the same effect by making sure all growable vmas in a given mm would share the same anon_vma, which we already lock here. However this turned out to be difficult - all of the schemes I tried for refcounting the growable anon_vma and clearing turned out ugly. So, I'm now proposing only the minimal fix. The overhead of taking the page table lock during stack expansion is expected to be small: glibc doesn't use expandable stacks for the threads it creates, so having multiple growable stacks is actually uncommon and we don't expect the page table lock to get bounced between threads. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2012-12-12 17:38:35 -08:00
..
backing-dev.c	backing-dev: use kstrto* in preference to simple_strtoul	2012-08-25 16:58:14 +08:00
balloon_compaction.c	mm: introduce a common interface for balloon pages mobility	2012-12-11 17:22:26 -08:00
bootmem.c	mm: introduce new field "managed_pages" to struct zone	2012-12-12 17:38:34 -08:00
bounce.c	bounce: allow use of bounce pool via config option	2012-07-18 16:40:35 -04:00
cleancache.c	->encode_fh() API change	2012-05-29 23:28:33 -04:00
compaction.c	mm: compaction: Fix compiler warning	2012-12-12 17:38:32 -08:00
debug-pagealloc.c	mm, x86: Remove debug_pagealloc_enabled	2011-12-06 09:24:07 +01:00
dmapool.c	dmapool: make DMAPOOL_DEBUG detect corruption of free marker	2012-12-11 17:22:24 -08:00
fadvise.c	switch simple cases of fget_light to fdget	2012-09-26 22:20:08 -04:00
failslab.c	switch debugfs to umode_t	2012-01-03 22:54:56 -05:00
filemap.c	readahead: fault retry breaks mmap file read random detection	2012-10-09 16:22:47 +09:00
filemap_xip.c	mm: move all mmu notifier invocations to be done outside the PT lock	2012-10-09 16:22:58 +09:00
fremap.c	remap_file_pages: correctly handle the case of a NULL vm_ops pointer	2012-10-19 13:37:57 -07:00
frontswap.c	frontswap: support exclusive gets if tmem backend is capable	2012-09-21 10:38:12 -04:00
highmem.c	mm, highmem: get virtual address of the page using PKMAP_ADDR()	2012-12-11 17:22:24 -08:00
huge_memory.c	thp: avoid race on multiple parallel page faults to the same page	2012-12-12 17:38:32 -08:00
hugetlb.c	hugetlb: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:33 -08:00
hugetlb_cgroup.c	cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free()	2012-11-19 08:13:38 -08:00
hwpoison-inject.c	memcg: rename config variables	2012-07-31 18:42:43 -07:00
init-mm.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
internal.h	mm: introduce mm_find_pmd()	2012-12-11 17:22:22 -08:00
interval_tree.c	mm: add CONFIG_DEBUG_VM_RB build option	2012-10-09 16:22:42 +09:00
Kconfig	numa: add CONFIG_MOVABLE_NODE for movable-dedicated node	2012-12-12 17:38:34 -08:00
Kconfig.debug	mm: more intensive memory corruption debugging	2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c	kmemleak: remove memset by using kzalloc	2011-01-27 18:31:51 +00:00
kmemleak.c	kmemleak: use rbtree instead of prio tree	2012-10-09 16:22:39 +09:00
ksm.c	mm, oom: fix race when specifying a thread as the oom origin	2012-12-11 17:22:27 -08:00
maccess.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
madvise.c	mm: prepare VM_DONTDUMP for using in drivers	2012-10-09 16:22:18 +09:00
Makefile	mm: introduce a common interface for balloon pages mobility	2012-12-11 17:22:26 -08:00
memblock.c	x86, mm: Trim memory in memblock to be page aligned	2012-10-24 11:52:21 -07:00
memcontrol.c	memcg: do not check for mm in __mem_cgroup_count_vm_event	2012-12-12 17:38:35 -08:00
memory-failure.c	mm: hwpoison: fix action_result() to print out dirty/clean	2012-12-11 17:22:24 -08:00
memory.c	thp: change split_huge_page_pmd() interface	2012-12-12 17:38:31 -08:00
memory_hotplug.c	mm: introduce new field "managed_pages" to struct zone	2012-12-12 17:38:34 -08:00
mempolicy.c	mempolicy: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:33 -08:00
mempool.c	mempool: add @gfp_mask to mempool_create_node()	2012-06-25 11:53:47 +02:00
migrate.c	mm,migrate: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:33 -08:00
mincore.c	mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode	2012-03-21 17:54:54 -07:00
mlock.c	mm, thp: fix mlock statistics	2012-10-09 16:23:03 +09:00
mm_init.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
mmap.c	mm: protect against concurrent vma expansion	2012-12-12 17:38:35 -08:00
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: allocate mmu_notifier in advance	2012-10-25 14:37:53 -07:00
mmzone.c	memcg: fix hotplugged memory zone oops	2012-11-16 14:33:04 -08:00
mprotect.c	thp: change split_huge_page_pmd() interface	2012-12-12 17:38:31 -08:00
mremap.c	thp: change split_huge_page_pmd() interface	2012-12-12 17:38:31 -08:00
msync.c
nobootmem.c	mm: introduce new field "managed_pages" to struct zone	2012-12-12 17:38:34 -08:00
nommu.c	mm: export a function to get vm committed memory	2012-11-15 15:41:22 -08:00
oom_kill.c	mm, oom: remove redundant sleep in pagefault oom handler	2012-12-12 17:38:34 -08:00
page-writeback.c	writeback: remove nr_pages_dirtied arg from balance_dirty_pages_ratelimited_nr()	2012-12-11 17:22:21 -08:00
page_alloc.c	mm: provide more accurate estimation of pages occupied by memmap	2012-12-12 17:38:35 -08:00
page_cgroup.c	memcontrol: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:32 -08:00
page_io.c	mm: add support for direct_IO to highmem pages	2012-07-31 18:42:47 -07:00
page_isolation.c	memory-hotplug: skip HWPoisoned page when offlining pages	2012-12-11 17:22:22 -08:00
pagewalk.c	thp: change split_huge_page_pmd() interface	2012-12-12 17:38:31 -08:00
percpu-km.c	percpu: clear memory allocated with the km allocator	2010-10-02 10:28:42 +03:00
percpu-vm.c	mm: fix kernel-doc warnings	2012-06-20 14:39:36 -07:00
percpu.c	mm, percpu: Make sure percpu_alloc early parameter has an argument	2012-12-02 06:23:04 -08:00
pgtable-generic.c	thp: introduce pmdp_invalidate()	2012-10-09 16:22:29 +09:00
process_vm_access.c	aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()	2012-05-31 17:49:32 -07:00
quicklist.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
readahead.c	switch simple cases of fget_light to fdget	2012-09-26 22:20:08 -04:00
rmap.c	mm: add comment on storage key dirty bit semantics	2012-12-11 17:22:23 -08:00
shmem.c	tmpfs: support SEEK_DATA and SEEK_HOLE (reprise)	2012-12-12 17:38:35 -08:00
slab.c	Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux	2012-10-07 07:53:13 +09:00
slab.h	Revert "mm/sl[aou]b: Move sysfs_slab_add to common"	2012-09-05 12:07:44 +03:00
slab_common.c	mm, slab: release slab_mutex earlier in kmem_cache_destroy()	2012-10-10 09:25:08 +03:00
slob.c	Merge branch 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc into fixes	2012-10-19 15:40:18 -07:00
slub.c	slub, hotplug: ignore unrelated node's hot-adding and hot-removing	2012-12-11 17:22:23 -08:00
sparse-vmemmap.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
sparse.c	memory-hotplug, mm/sparse.c: clear the memory to store struct page	2012-12-11 17:22:23 -08:00
swap.c	mm: remove vma arg from page_evictable	2012-10-09 16:22:55 +09:00
swap_state.c	mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages	2012-07-31 18:42:47 -07:00
swapfile.c	mm, oom: fix race when specifying a thread as the oom origin	2012-12-11 17:22:27 -08:00
truncate.c	mm: use clear_page_mlock() in page_remove_rmap()	2012-10-09 16:22:56 +09:00
util.c	mm: Use __do_krealloc to do the krealloc job	2012-09-04 10:22:58 +03:00
vmalloc.c	mm: use IS_ENABLED(CONFIG_NUMA) instead of NUMA_BUILD	2012-12-11 17:22:22 -08:00
vmscan.c	vmscan: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:33 -08:00
vmstat.c	mm: introduce new field "managed_pages" to struct zone	2012-12-12 17:38:34 -08:00