Subject: + mm-rmap-use-rmap_walk-in-page_referenced-fix.patch added to -mm tree
To: liwanp@xxxxxxxxxxxxxxxxxx,bob.liu@xxxxxxxxxx,dhillf@xxxxxxxxx,hughd@xxxxxxxxxx,iamjoonsoo.kim@xxxxxxx,mgorman@xxxxxxx,mingo@xxxxxxxxxx,n-horiguchi@xxxxxxxxxxxxx,riel@xxxxxxxxxx,sasha.levin@xxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Thu, 19 Dec 2013 12:03:33 -0800
The patch titled
Subject: mm/rmap: fix BUG at rmap_walk
has been added to the -mm tree. Its filename is
mm-rmap-use-rmap_walk-in-page_referenced-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-rmap-use-rmap_walk-in-page_referenced-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-rmap-use-rmap_walk-in-page_referenced-fix.patch
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------------------------------------------------------
From: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
Subject: mm/rmap: fix BUG at rmap_walk
This bug is introduced by commit 37f093cdf(mm/rmap: use rmap_walk() in
page_referenced()). page_get_anon_vma() called in page_referenced_anon()
will lock and increase the refcount of anon_vma. PageLocked is not
required by page_referenced_anon() and there is not any assertion before,
commit 37f093cdf introduced this extra BUG_ON() checking for anon page by
mistake. This patch fix it by remove rmap_walk()'s VM_BUG_ON() and
comment reason why the page must be locked for rmap_walk_ksm() and
rmap_walk_file().
[ 588.698828] kernel BUG at mm/rmap.c:1663!
[ 588.699380] invalid opcode: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC
[ 588.700347] Dumping ftrace buffer:
[ 588.701186] (ftrace buffer empty)
[ 588.702062] Modules linked in:
[ 588.702759] CPU: 0 PID: 4647 Comm: kswapd0 Tainted: G D W 3.13.0-rc4-next-20131218-sasha-00012-g1962367-dirty #4155
[ 588.704330] task: ffff880062bcb000 ti: ffff880062450000 task.ti: ffff880062450000
[ 588.705507] RIP: 0010:[<ffffffff81289c80>] [<ffffffff81289c80>] rmap_walk+0x10/0x50
[ 588.706800] RSP: 0018:ffff8800624518d8 EFLAGS: 00010246
[ 588.707515] RAX: 000fffff80080048 RBX: ffffea00000227c0 RCX: 0000000000000000
[ 588.707515] RDX: 0000000000000000 RSI: ffff8800624518e8 RDI: ffffea00000227c0
[ 588.707515] RBP: ffff8800624518d8 R08: ffff8800624518e8 R09: 0000000000000000
[ 588.707515] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800624519d8
[ 588.707515] R13: 0000000000000000 R14: ffffea00000227e0 R15: 0000000000000000
[ 588.707515] FS: 0000000000000000(0000) GS:ffff880065200000(0000) knlGS:0000000000000000
[ 588.707515] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 588.707515] CR2: 00007fec40cbe0f8 CR3: 00000000c2382000 CR4: 00000000000006f0
[ 588.707515] Stack:
[ 588.707515] ffff880062451958 ffffffff81289f4b ffff880062451918 ffffffff81289f80
[ 588.707515] 0000000000000000 0000000000000000 ffffffff8128af60 0000000000000000
[ 588.707515] 0000000000000024 0000000000000000 0000000000000000 0000000000000286
[ 588.707515] Call Trace:
[ 588.707515] [<ffffffff81289f4b>] page_referenced+0xcb/0x100
[ 588.707515] [<ffffffff81289f80>] ? page_referenced+0x100/0x100
[ 588.707515] [<ffffffff8128af60>] ? invalid_page_referenced_vma+0x170/0x170
[ 588.707515] [<ffffffff81264302>] shrink_active_list+0x212/0x330
[ 588.707515] [<ffffffff81260e23>] ? inactive_file_is_low+0x33/0x50
[ 588.707515] [<ffffffff812646f5>] shrink_lruvec+0x2d5/0x300
[ 588.707515] [<ffffffff812647b6>] shrink_zone+0x96/0x1e0
[ 588.707515] [<ffffffff81265b06>] kswapd_shrink_zone+0xf6/0x1c0
[ 588.707515] [<ffffffff81265f43>] balance_pgdat+0x373/0x550
[ 588.707515] [<ffffffff81266d63>] kswapd+0x2f3/0x350
[ 588.707515] [<ffffffff81266a70>] ? perf_trace_mm_vmscan_lru_isolate_template+0x120/0x120
[ 588.707515] [<ffffffff8115c9c5>] kthread+0x105/0x110
[ 588.707515] [<ffffffff8115c8c0>] ? set_kthreadd_affinity+0x30/0x30
[ 588.707515] [<ffffffff843a6a7c>] ret_from_fork+0x7c/0xb0
[ 588.707515] [<ffffffff8115c8c0>] ? set_kthreadd_affinity+0x30/0x30
[ 588.707515] Code: c0 48 83 c4 18 89 d0 5b 41 5c 41 5d 41 5e 41 5f c9 c3 66 0f 1f 84
00 00 00 00 00 55 48 89 e5 66 66 66 66 90 48 8b 07 a8 01 75 10 <0f> 0b 66 0f 1f 44 00 0
0 eb fe 66 0f 1f 44 00 00 f6 47 08 01 74
[ 588.707515] RIP [<ffffffff81289c80>] rmap_walk+0x10/0x50
[ 588.707515] RSP <ffff8800624518d8>
Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Reviewed-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Hillf Danton <dhillf@xxxxxxxxx>
Cc: Bob Liu <bob.liu@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 5 +++++
mm/rmap.c | 10 ++++++++--
2 files changed, 13 insertions(+), 2 deletions(-)
diff -puN mm/ksm.c~mm-rmap-use-rmap_walk-in-page_referenced-fix mm/ksm.c
--- a/mm/ksm.c~mm-rmap-use-rmap_walk-in-page_referenced-fix
+++ a/mm/ksm.c
@@ -1899,6 +1899,11 @@ int rmap_walk_ksm(struct page *page, str
int search_new_forks = 0;
VM_BUG_ON(!PageKsm(page));
+
+ /*
+ * Rely on the page lock to protect against concurrent modifications
+ * to that page's node of the stable tree.
+ */
VM_BUG_ON(!PageLocked(page));
stable_node = page_stable_node(page);
diff -puN mm/rmap.c~mm-rmap-use-rmap_walk-in-page_referenced-fix mm/rmap.c
--- a/mm/rmap.c~mm-rmap-use-rmap_walk-in-page_referenced-fix
+++ a/mm/rmap.c
@@ -1632,6 +1632,14 @@ static int rmap_walk_file(struct page *p
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;
+ /*
+ * The page lock not only makes sure that page->mapping cannot
+ * suddenly be NULLified by truncation, it makes sure that the
+ * structure at mapping cannot be freed and reused yet,
+ * so we can safely take mapping->i_mmap_mutex.
+ */
+ VM_BUG_ON(!PageLocked(page));
+
if (!mapping)
return ret;
mutex_lock(&mapping->i_mmap_mutex);
@@ -1663,8 +1671,6 @@ done:
int rmap_walk(struct page *page, struct rmap_walk_control *rwc)
{
- VM_BUG_ON(!PageLocked(page));
-
if (unlikely(PageKsm(page)))
return rmap_walk_ksm(page, rwc);
else if (PageAnon(page))
_
Patches currently in -mm which might be from liwanp@xxxxxxxxxxxxxxxxxx are
origin.patch
x86-get-pg_data_ts-memory-from-other-node.patch
memblock-numa-introduce-flags-field-into-memblock.patch
memblock-mem_hotplug-introduce-memblock_hotplug-flag-to-mark-hotpluggable-regions.patch
memblock-make-memblock_set_node-support-different-memblock_type.patch
acpi-numa-mem_hotplug-mark-hotpluggable-memory-in-memblock.patch
acpi-numa-mem_hotplug-mark-all-nodes-the-kernel-resides-un-hotpluggable.patch
memblock-mem_hotplug-make-memblock-skip-hotpluggable-regions-if-needed.patch
x86-numa-acpi-memory-hotplug-make-movable_node-have-higher-priority.patch
mm-rmap-use-rmap_walk-in-page_referenced-fix.patch
mm-hwpoison-add-to-hwpoison_inject.patch
lib-show_memc-show-num_poisoned_pages-when-oom.patch
mm-migrate-add-comment-about-permanent-failure-path.patch
mm-migrate-correct-failure-handling-if-hugepage_migration_support.patch
mm-migrate-remove-putback_lru_pages-fix-comment-on-putback_movable_pages.patch
mm-migrate-remove-unused-function-fail_migrate_page.patch
mm-documentation-remove-hopelessly-out-of-date-locking-doc.patch
mm-remove-bug_on-from-mlock_vma_page.patch
linux-next.patch
mm-migratec-fix-set-cpupid-on-page-migration-twice-against-thp.patch
mm-migratec-fix-setting-of-cpupid-on-page-migration-twice-against-normal-page.patch
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