The patch titled
Subject: mm/compaction.c: abort search if isolation fails
has been added to the -mm tree. Its filename is
mm-compaction-abort-search-if-isolation-fails-v2.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-compaction-abort-search-if-isolation-fails-v2.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-compaction-abort-search-if-isolation-fails-v2.patch
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------------------------------------------------------
From: Qian Cai <cai@xxxxxx>
Subject: mm/compaction.c: abort search if isolation fails
Running LTP oom01 in a tight loop or memory stress testing put the system
in a low-memory situation could triggers random memory corruption like
page flag corruption below due to in fast_isolate_freepages(), if
isolation fails, next_search_order() does not abort the search immediately
could lead to improper accesses.
UBSAN: Undefined behaviour in ./include/linux/mm.h:1195:50
index 7 is out of range for type 'zone [5]'
Call Trace:
dump_stack+0x62/0x9a
ubsan_epilogue+0xd/0x7f
__ubsan_handle_out_of_bounds+0x14d/0x192
__isolate_free_page+0x52c/0x600
compaction_alloc+0x886/0x25f0
unmap_and_move+0x37/0x1e70
migrate_pages+0x2ca/0xb20
compact_zone+0x19cb/0x3620
kcompactd_do_work+0x2df/0x680
kcompactd+0x1d8/0x6c0
kthread+0x32c/0x3f0
ret_from_fork+0x35/0x40
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:3124!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
RIP: 0010:__isolate_free_page+0x464/0x600
RSP: 0000:ffff888b9e1af848 EFLAGS: 00010007
RAX: 0000000030000000 RBX: ffff888c39fcf0f8 RCX: 0000000000000000
RDX: 1ffff111873f9e25 RSI: 0000000000000004 RDI: ffffed1173c35ef6
RBP: ffff888b9e1af898 R08: fffffbfff4fc2461 R09: fffffbfff4fc2460
R10: fffffbfff4fc2460 R11: ffffffffa7e12303 R12: 0000000000000008
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000007
FS: 0000000000000000(0000) GS:ffff888ba8e80000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc7abc00000 CR3: 0000000752416004 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
compaction_alloc+0x886/0x25f0
unmap_and_move+0x37/0x1e70
migrate_pages+0x2ca/0xb20
compact_zone+0x19cb/0x3620
kcompactd_do_work+0x2df/0x680
kcompactd+0x1d8/0x6c0
kthread+0x32c/0x3f0
ret_from_fork+0x35/0x40
Link: http://lkml.kernel.org/r/20190320192648.52499-1-cai@xxxxxx
Fixes: dbe2d4e4f12e ("mm, compaction: round-robin the order while searching the free lists for a target")
Signed-off-by: Qian Cai <cai@xxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: Mikhail Gavrilov <mikhail.v.gavrilov@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/compaction.c~mm-compaction-abort-search-if-isolation-fails-v2
+++ a/mm/compaction.c
@@ -1363,7 +1363,7 @@ fast_isolate_freepages(struct compact_co
count_compact_events(COMPACTISOLATED, nr_isolated);
} else {
/* If isolation fails, abort the search */
- order = -1;
+ order = cc->search_order + 1;
page = NULL;
}
}
_
Patches currently in -mm which might be from cai@xxxxxx are
kasan-fix-variable-tag-set-but-not-used-warning.patch
mm-debug-add-a-cast-to-u64-for-atomic64_read.patch
kmemleak-skip-scanning-holes-in-the-bss-section.patch
kmemleak-skip-scanning-holes-in-the-bss-section-v2.patch
mm-hotplug-fix-offline-undo_isolate_page_range.patch
mm-compaction-abort-search-if-isolation-fails-v2.patch
