linux/mm
Johannes Weiner 22f2ac51b6 mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()
Antonio reports the following crash when using fuse under memory pressure:

  kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: all of them
  CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
  RIP: shadow_lru_isolate+0x181/0x190
  Call Trace:
    __list_lru_walk_one.isra.3+0x8f/0x130
    list_lru_walk_one+0x23/0x30
    scan_shadow_nodes+0x34/0x50
    shrink_slab.part.40+0x1ed/0x3d0
    shrink_zone+0x2ca/0x2e0
    kswapd+0x51e/0x990
    kthread+0xd8/0xf0
    ret_from_fork+0x3f/0x70

which corresponds to the following sanity check in the shadow node
tracking:

  BUG_ON(node->count & RADIX_TREE_COUNT_MASK);

The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.

While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page.  Eventually the page count bits in node->count underflow while
leaving the node incorrectly linked to the shadow node LRU.

To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert().  This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.

Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.

Fixes: 449dd6984d ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Antonio SJ Musumeci <trapexit@spawn.link>
Debugged-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>	[3.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-30 15:26:52 -07:00
..
kasan kasan: remove the unnecessary WARN_ONCE from quarantine.c 2016-08-11 16:58:14 -07:00
backing-dev.c block: fix bdi vs gendisk lifetime mismatch 2016-08-04 14:19:16 -06:00
balloon_compaction.c mm: balloon: use general non-lru movable page feature 2016-07-26 16:19:19 -07:00
bootmem.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
cleancache.c cleancache: constify cleancache_ops structure 2016-01-27 09:09:57 -05:00
cma_debug.c
cma.c mm/cma: silence warnings due to max() usage 2016-05-27 14:49:37 -07:00
cma.h
compaction.c mm, compaction: simplify contended compaction handling 2016-07-28 16:07:41 -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
debug.c mm: avoid endless recursion in dump_page() 2016-09-19 15:36:16 -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/fadvise.c: do not discard partial pages with POSIX_FADV_DONTNEED 2016-06-09 14:23:11 -07:00
failslab.c mm: fault-inject take over bootstrap kmem_cache check 2016-03-15 16:55:16 -07:00
filemap.c mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page() 2016-09-30 15:26:52 -07:00
frame_vector.c mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
frontswap.c mm, frontswap: convert frontswap_enabled to static key 2016-07-26 16:19:19 -07:00
gup.c - ARM: GICv3 ITS emulation and various fixes. Removal of the old 2016-08-02 16:11:27 -04:00
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 mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing 2016-09-25 15:43:42 -07:00
hugetlb_cgroup.c mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size 2016-05-20 17:58:30 -07:00
hugetlb.c mm/hugetlb: fix incorrect hugepages count during mem hotplug 2016-08-11 16:58:13 -07:00
hwpoison-inject.c
init-mm.c
internal.h mm, compaction: simplify contended compaction handling 2016-07-28 16:07:41 -07:00
interval_tree.c
Kconfig mm: clarify COMPACTION Kconfig text 2016-08-26 17:39:35 -07:00
Kconfig.debug mm/page_ref: add tracepoint to track down page reference manipulation 2016-03-17 15:09:34 -07:00
khugepaged.c mm, thp: fix leaking mapped pte in __collapse_huge_page_swapin() 2016-09-19 15:36:16 -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 kmemleak: don't hang if user disables scanning early 2016-07-28 16:07:41 -07:00
ksm.c mm,ksm: fix endless looping in allocating memory when ksm enable 2016-09-28 16:19:01 -07:00
list_lru.c mm: memcontrol: move kmem accounting code to CONFIG_MEMCG 2016-01-20 17:09:18 -08:00
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 Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00
memblock.c mm/memblock.c: fix NULL dereference error 2016-08-04 20:02:09 -04:00
memcontrol.c mm: memcontrol: make per-cpu charge cache IRQ-safe for socket accounting 2016-09-19 15:36:17 -07:00
memory_hotplug.c mem-hotplug: use nodes that contain memory as mask in new_node_page() 2016-09-28 16:19:02 -07:00
memory-failure.c mm: hwpoison: remove incorrect comments 2016-07-28 16:07:41 -07:00
memory.c mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing 2016-09-25 15:43:42 -07:00
mempolicy.c mm, mempolicy: task->mempolicy must be NULL before dropping final reference 2016-09-01 17:52:01 -07:00
mempool.c Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements" 2016-07-28 16:07:41 -07:00
memtest.c
migrate.c mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations 2016-07-28 16:07:41 -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, vmscan: move LRU lists to node 2016-07-28 16:07:41 -07:00
mm_init.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
mmap.c mm: refuse wrapped vm_brk requests 2016-08-02 19:35:15 -04:00
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: thp: check pmd_trans_unstable() after split_huge_pmd() 2016-07-26 16:19:19 -07:00
mremap.c mm: thp: check pmd_trans_unstable() after split_huge_pmd() 2016-07-26 16:19:19 -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: introduce fault_env 2016-07-26 16:19:19 -07:00
oom_kill.c mm, oom: fix uninitialized ret in task_will_free_mem() 2016-08-11 16:58:14 -07:00
page_alloc.c mm, vmscan: only allocate and reclaim from zones with pages managed by the buddy allocator 2016-09-01 17:52:01 -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 mm, vmscan: move lru_lock to the node 2016-07-28 16:07:41 -07:00
page_io.c mm: fix the page_swap_info() BUG_ON check 2016-09-19 15:36:17 -07:00
page_isolation.c mm/page_isolation: clean up confused code 2016-07-26 16:19:19 -07:00
page_owner.c mm/page_owner: use stackdepot to store stacktrace 2016-07-26 16:19:19 -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
page-writeback.c mm: remove reclaim and compaction retry approximations 2016-07-28 16:07:41 -07:00
pagewalk.c thp: rename split_huge_page_pmd() to split_huge_pmd() 2016-01-15 17:56:32 -08:00
percpu-km.c mm: percpu: use pr_fmt to prefix output 2016-03-17 15:09:34 -07:00
percpu-vm.c
percpu.c percpu: fix synchronization between synchronous map extension and chunk destruction 2016-05-25 11:48:25 -04:00
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 mm/gup: Introduce get_user_pages_remote() 2016-02-16 10:04:09 +01:00
quicklist.c fix Christoph's email addresses 2016-03-17 15:09:34 -07:00
readahead.c mm: silently skip readahead for DAX inodes 2016-08-26 17:39:35 -07:00
rmap.c rmap: fix compound check logic in page_remove_file_rmap 2016-08-10 16:40:56 -07:00
shmem.c huge tmpfs: fix Committed_AS leak 2016-09-24 11:20:01 -07:00
slab_common.c mm: charge/uncharge kmemcg from generic page allocator paths 2016-07-26 16:19:19 -07:00
slab.c Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00
slab.h mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB 2016-07-28 16:07:41 -07:00
slob.c mm: slab: free kmem_cache_node after destroy sysfs file 2016-02-18 16:23:24 -08:00
slub.c mm/slub.c: run free_partial() outside of the kmem_cache_node->list_lock 2016-08-10 16:40:56 -07:00
sparse-vmemmap.c treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
sparse.c treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
swap_cgroup.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
swap_state.c mm: move most file-based accounting to the node 2016-07-28 16:07:41 -07:00
swap.c mm, pagevec: release/reacquire lru_lock on pgdat change 2016-07-28 16:07:41 -07:00
swapfile.c mm: fix the page_swap_info() BUG_ON check 2016-09-19 15:36:17 -07:00
truncate.c truncate: handle file thp 2016-07-26 16:19:19 -07:00
usercopy.c mm: usercopy: Check for module addresses 2016-09-20 16:07:39 -07:00
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: move most file-based accounting to the node 2016-07-28 16:07:41 -07:00
vmacache.c
vmalloc.c mm: charge/uncharge kmemcg from generic page allocator paths 2016-07-26 16:19:19 -07:00
vmpressure.c mm/vmpressure.c: fix subtree pressure detection 2016-02-03 08:28:43 -08:00
vmscan.c mm: delete unnecessary and unsafe init_tlb_ubc() 2016-09-24 11:20:01 -07:00
vmstat.c mm: remove reclaim and compaction retry approximations 2016-07-28 16:07:41 -07:00
workingset.c mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page() 2016-09-30 15:26:52 -07:00
z3fold.c mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup 2016-06-03 16:02:55 -07:00
zbud.c mm/zbud.c: use list_last_entry() instead of list_tail_entry() 2016-01-15 11:40:52 -08:00
zpool.c
zsmalloc.c zsmalloc: Delete an unnecessary check before the function call "iput" 2016-07-28 16:07:41 -07:00
zswap.c mm/zswap: use workqueue to destroy pool 2016-05-20 17:58:30 -07:00