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	mm/cma_debug: correct size input to bitmap function	2015-07-17 16:39:54 -07:00
cma.c	mm/cma: silence warnings due to max() usage	2016-05-27 14:49:37 -07:00
cma.h	mm: cma: mark cma_bitmap_maxno() inline in header	2015-08-14 15:56:32 -07:00
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	mm/early_ioremap: use offset_in_page macro	2015-11-05 19:34:48 -08:00
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	hwpoison: use page_cgroup_ino for filtering by memcg	2015-09-10 13:29:01 -07:00
init-mm.c
internal.h	mm, compaction: simplify contended compaction handling	2016-07-28 16:07:41 -07:00
interval_tree.c	mm: replace vma->sharead.linear with vma->shared	2015-02-10 14:30:31 -08:00
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	memtest: remove unused header files	2015-09-08 15:35:28 -07:00
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	mm/msync: use offset_in_page macro	2015-11-05 19:34:48 -08:00
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	mm: page_counter: let page_counter_try_charge() return bool	2015-11-05 19:34:48 -08:00
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	mm/vmacache: inline vmacache_valid_mm()	2015-11-05 19:34:48 -08:00
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	mm: zsmalloc: constify struct zs_pool name	2015-11-06 17:50:42 -08:00
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