Tejun Heo 3a06bb78ce memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem() ... memcg_offline_kmem() may be called from memcg_free_kmem() after a css init failure. memcg_free_kmem() is a ->css_free callback which is called without cgroup_mutex and memcg_offline_kmem() ends up using css_for_each_descendant_pre() without any locking. Fix it by adding rcu read locking around it. mkdir: cannot create directory `65530': No space left on device =============================== [ INFO: suspicious RCU usage. ] 4.6.0-work+ #321 Not tainted ------------------------------- kernel/cgroup.c:4008 cgroup_mutex or RCU read lock required! [ 527.243970] other info that might help us debug this: [ 527.244715] rcu_scheduler_active = 1, debug_locks = 0 2 locks held by kworker/0:5/1664: #0: ("cgroup_destroy"){.+.+..}, at: [<ffffffff81060ab5>] process_one_work+0x165/0x4a0 #1: ((&css->destroy_work)#3){+.+...}, at: [<ffffffff81060ab5>] process_one_work+0x165/0x4a0 [ 527.248098] stack backtrace: CPU: 0 PID: 1664 Comm: kworker/0:5 Not tainted 4.6.0-work+ #321 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 Workqueue: cgroup_destroy css_free_work_fn Call Trace: dump_stack+0x68/0xa1 lockdep_rcu_suspicious+0xd7/0x110 css_next_descendant_pre+0x7d/0xb0 memcg_offline_kmem.part.44+0x4a/0xc0 mem_cgroup_css_free+0x1ec/0x200 css_free_work_fn+0x49/0x5e0 process_one_work+0x1c5/0x4a0 worker_thread+0x49/0x490 kthread+0xea/0x100 ret_from_fork+0x1f/0x40 Link: http://lkml.kernel.org/r/20160526203018.GG23194@mtj.duckdns.org Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-06-03 16:02:55 -07:00
..
kasan	mm: kasan: remove unused 'reserved' field from struct kasan_alloc_meta	2016-05-26 15:35:44 -07:00
backing-dev.c	mm: throttle on IO only when there are too many dirty and writeback pages	2016-05-20 17:58:30 -07:00
balloon_compaction.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2016-03-17 21:38:27 -07:00
bootmem.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
cleancache.c
cma.c	mm/cma: silence warnings due to max() usage	2016-05-27 14:49:37 -07:00
cma.h
cma_debug.c
compaction.c	mm/compaction.c: fix zoneindex in kcompactd()	2016-05-20 17:58:30 -07:00
debug.c	mm: introduce page reference manipulation functions	2016-03-17 15:09:34 -07:00
debug_page_ref.c	mm/page_ref: add tracepoint to track down page reference manipulation	2016-03-17 15:09:34 -07:00
dmapool.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
early_ioremap.c
fadvise.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
failslab.c
filemap.c	Filesystem DAX locking for 4.7	2016-05-26 20:00:28 -07:00
frame_vector.c
frontswap.c
gup.c	Merge branch 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-04-14 19:31:34 -07:00
highmem.c	mm/highmem: make nr_free_highpages() handles all highmem zones by itself	2016-05-19 19:12:14 -07:00
huge_memory.c	libnvdimm for 4.7	2016-05-23 11:18:01 -07:00
hugetlb.c	libnvdimm for 4.7	2016-05-23 11:18:01 -07:00
hugetlb_cgroup.c	mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size	2016-05-20 17:58:30 -07:00
hwpoison-inject.c
init-mm.c
internal.h	mm: make vm_mmap killable	2016-05-23 17:04:14 -07:00
interval_tree.c
Kconfig	mm: disable DEFERRED_STRUCT_PAGE_INIT on !NO_BOOTMEM	2016-05-27 14:49:37 -07:00
Kconfig.debug	mm/page_ref: add tracepoint to track down page reference manipulation	2016-03-17 15:09:34 -07:00
kmemcheck.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak-test.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
kmemleak.c	mm: coalesce split strings	2016-03-17 15:09:34 -07:00
ksm.c	ksm: fix conflict between mmput and scan_get_next_rmap_item	2016-05-12 15:52:50 -07:00
list_lru.c
maccess.c	x86: remove more uaccess_32.h complexity	2016-05-22 17:21:27 -07:00
madvise.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
Makefile	z3fold: the 3-fold allocator for compressed pages	2016-05-20 17:58:30 -07:00
memblock.c	mm/memblock.c: remove unnecessary always-true comparison	2016-05-20 17:58:30 -07:00
memcontrol.c	memcg: add RCU locking around css_for_each_descendant_pre() in memcg_offline_kmem()	2016-06-03 16:02:55 -07:00
memory-failure.c	mm/memory-failure.c: replace "MCE" with "Memory failure"	2016-05-20 17:58:30 -07:00
memory.c	Filesystem DAX locking for 4.7	2016-05-26 20:00:28 -07:00
memory_hotplug.c	mm: fix section mismatch warning	2016-05-27 15:23:32 -07:00
mempolicy.c	mm, page_alloc: avoid looking up the first zone in a zonelist twice	2016-05-19 19:12:14 -07:00
mempool.c	mm: kasan: initial memory quarantine implementation	2016-05-20 17:58:30 -07:00
memtest.c
migrate.c	mm, migrate: increment fail count on ENOMEM	2016-05-20 17:58:30 -07:00
mincore.c	mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage	2016-04-04 10:41:08 -07:00
mlock.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
mm_init.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
mmap.c	mm: remove more IS_ERR_VALUE abuses	2016-05-27 15:57:31 -07:00
mmu_context.c	mm/mmu_context, sched/core: Fix mmu_context.h assumption	2016-04-28 11:44:19 +02:00
mmu_notifier.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
mmzone.c	mm, page_alloc: inline the fast path of the zonelist iterator	2016-05-19 19:12:14 -07:00
mprotect.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
mremap.c	mm: make mmap_sem for write waits killable for mm syscalls	2016-05-23 17:04:14 -07:00
msync.c
nobootmem.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
nommu.c	mm: remove more IS_ERR_VALUE abuses	2016-05-27 15:57:31 -07:00
oom_kill.c	oom_reaper: close race with exiting task	2016-05-27 14:49:37 -07:00
page-writeback.c	MM: increase safety margin provided by PF_LESS_THROTTLE	2016-05-20 17:58:30 -07:00
page_alloc.c	mm: check the return value of lookup_page_ext for all call sites	2016-06-03 15:06:22 -07:00
page_counter.c
page_ext.c	mm: use early_pfn_to_nid in page_ext_init	2016-05-27 14:49:37 -07:00
page_idle.c
page_io.c	Merge branch 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-05-17 15:05:23 -07:00
page_isolation.c	mm/memory_hotplug: add comment to some functions related to memory hotplug	2016-05-19 19:12:14 -07:00
page_owner.c	mm: check the return value of lookup_page_ext for all call sites	2016-06-03 15:06:22 -07:00
page_poison.c	mm: check the return value of lookup_page_ext for all call sites	2016-06-03 15:06:22 -07:00
pagewalk.c
percpu-km.c	mm: percpu: use pr_fmt to prefix output	2016-03-17 15:09:34 -07:00
percpu-vm.c
percpu.c	mm: percpu: use pr_fmt to prefix output	2016-03-17 15:09:34 -07:00
pgtable-generic.c	mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range	2016-03-17 15:09:34 -07:00
process_vm_access.c
quicklist.c	fix Christoph's email addresses	2016-03-17 15:09:34 -07:00
readahead.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
rmap.c	mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()	2016-05-27 14:49:37 -07:00
shmem.c	switch xattr_handler->set() to passing dentry and inode separately	2016-05-27 15:39:43 -04:00
slab.c	mm, kasan: don't call kasan_krealloc() from ksize().	2016-05-20 17:58:30 -07:00
slab.h	mm: kasan: initial memory quarantine implementation	2016-05-20 17:58:30 -07:00
slab_common.c	mm: kasan: initial memory quarantine implementation	2016-05-20 17:58:30 -07:00
slob.c
slub.c	mm, kasan: don't call kasan_krealloc() from ksize().	2016-05-20 17:58:30 -07:00
sparse-vmemmap.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
sparse.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
swap.c	mm/swap.c: put activate_page_pvecs and other pagevecs together	2016-05-20 17:58:30 -07:00
swap_cgroup.c	mm: convert printk(KERN_<LEVEL> to pr_<level>	2016-03-17 15:09:34 -07:00
swap_state.c	mm: use __SetPageSwapBacked and dont ClearPageSwapBacked	2016-05-19 19:12:14 -07:00
swapfile.c	mm: thp: calculate the mapcount correctly for THP pages during WP faults	2016-05-12 15:52:50 -07:00
truncate.c	dax: New fault locking	2016-05-19 15:20:54 -06:00
userfaultfd.c	mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros	2016-04-04 10:41:08 -07:00
util.c	mm: make vm_mmap killable	2016-05-23 17:04:14 -07:00
vmacache.c
vmalloc.c	mm: fix overflow in vm_map_ram()	2016-06-03 15:06:22 -07:00
vmpressure.c
vmscan.c	mm, oom: rework oom detection	2016-05-20 17:58:30 -07:00
vmstat.c	mm: check the return value of lookup_page_ext for all call sites	2016-06-03 15:06:22 -07:00
workingset.c	mm: workingset: make shadow node shrinker memcg aware	2016-03-17 15:09:34 -07:00
z3fold.c	z3fold: the 3-fold allocator for compressed pages	2016-05-20 17:58:30 -07:00
zbud.c
zpool.c
zsmalloc.c	update "mm/zsmalloc: don't fail if can't create debugfs info"	2016-05-26 15:35:44 -07:00
zswap.c	mm/zswap: use workqueue to destroy pool	2016-05-20 17:58:30 -07:00