diff mbox series

[02/11] mm: fix trying to reclaim unevictable lru page when calling madvise_pageout

Message ID 20191116013436.Y6v9iJYo8%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/11] mm: mempolicy: fix the wrong return value and potential pages leak of mbind | expand

Commit Message

Andrew Morton Nov. 16, 2019, 1:34 a.m. UTC 
From: zhong jiang <zhongjiang@huawei.com>
Subject: mm: fix trying to reclaim unevictable lru page when calling madvise_pageout

Recently, I hit the following issue when running upstream.

kernel BUG at mm/vmscan.c:1521!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 PID: 23385 Comm: syz-executor.6 Not tainted 5.4.0-rc4+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:shrink_page_list+0x12b6/0x3530 mm/vmscan.c:1521
Code: de f5 ff ff e8 ab 79 eb ff 4c 89 f7 e8 43 33 0d 00 e9 cc f5 ff ff e8 99 79 eb ff 48 c7 c6 a0 34 2b a0 4c 89 f7 e8 1a 4d 05 00 <0f> 0b e8 83 79 eb ff 48 89 d8 48 c1 e8 03 42 80 3c 38 00 0f 85 74
RSP: 0018:ffff88819a3df5a0 EFLAGS: 00010286
RAX: 0000000000040000 RBX: ffffea00061c3980 RCX: ffffffff814fba36
RDX: 00000000000056f7 RSI: ffffc9000c02c000 RDI: ffff8881f70268cc
RBP: ffff88819a3df898 R08: ffffed103ee05de0 R09: ffffed103ee05de0
R10: 0000000000000001 R11: ffffed103ee05ddf R12: ffff88819a3df6f0
R13: ffff88819a3df6f0 R14: ffffea00061c3980 R15: dffffc0000000000
FS:  00007f21b9d8e700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d621000 CR3: 00000001c8c46004 CR4: 00000000007606f0
DR0: 0000000020000140 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
PKRU: 55555554
Call Trace:
 reclaim_pages+0x499/0x800 mm/vmscan.c:2188
 madvise_cold_or_pageout_pte_range+0x58a/0x710 mm/madvise.c:453
 walk_pmd_range mm/pagewalk.c:53 [inline]
 walk_pud_range mm/pagewalk.c:112 [inline]
 walk_p4d_range mm/pagewalk.c:139 [inline]
 walk_pgd_range mm/pagewalk.c:166 [inline]
 __walk_page_range+0x45a/0xc20 mm/pagewalk.c:261
 walk_page_range+0x179/0x310 mm/pagewalk.c:349
 madvise_pageout_page_range mm/madvise.c:506 [inline]
 madvise_pageout+0x1f0/0x330 mm/madvise.c:542
 madvise_vma mm/madvise.c:931 [inline]
 __do_sys_madvise+0x7d2/0x1600 mm/madvise.c:1113
 do_syscall_64+0x9f/0x4c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

madvise_pageout() accesses the specified range of the vma and isolates
them, then runs shrink_page_list() to reclaim its memory.  But it also
isolates the unevictable pages to reclaim.  Hence, we can catch the cases
in shrink_page_list().

The root cause is that we scan the page tables instead of specific LRU
list.  and so we need to filter out the unevictable lru pages from our
end.

Link: http://lkml.kernel.org/r/1572616245-18946-1-git-send-email-zhongjiang@huawei.com
Fixes: 1a4e58cce84e ("mm: introduce MADV_PAGEOUT")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/madvise.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)
diff mbox series

Patch

--- a/mm/madvise.c~mm-fix-trying-to-reclaim-unevictable-lru-page-when-calling-madvise_pageout
+++ a/mm/madvise.c
@@ -363,8 +363,12 @@  static int madvise_cold_or_pageout_pte_r
 		ClearPageReferenced(page);
 		test_and_clear_page_young(page);
 		if (pageout) {
-			if (!isolate_lru_page(page))
-				list_add(&page->lru, &page_list);
+			if (!isolate_lru_page(page)) {
+				if (PageUnevictable(page))
+					putback_lru_page(page);
+				else
+					list_add(&page->lru, &page_list);
+			}
 		} else
 			deactivate_page(page);
 huge_unlock:
@@ -441,8 +445,12 @@  regular_page:
 		ClearPageReferenced(page);
 		test_and_clear_page_young(page);
 		if (pageout) {
-			if (!isolate_lru_page(page))
-				list_add(&page->lru, &page_list);
+			if (!isolate_lru_page(page)) {
+				if (PageUnevictable(page))
+					putback_lru_page(page);
+				else
+					list_add(&page->lru, &page_list);
+			}
 		} else
 			deactivate_page(page);
 	}