From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, cai@lca.pw, elver@google.com,
linux-mm@kvack.org, mm-commits@vger.kernel.org,
torvalds@linux-foundation.org
Subject: [patch 30/39] mm/rmap: annotate a data race at tlb_flush_batched
Date: Fri, 14 Aug 2020 17:31:47 -0700 [thread overview]
Message-ID: <20200815003147.tvfApJQ2K%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200814172939.55d6d80b6e21e4241f1ee1f3@linux-foundation.org>
From: Qian Cai <cai@lca.pw>
Subject: mm/rmap: annotate a data race at tlb_flush_batched
mm->tlb_flush_batched could be accessed concurrently as noticed by
KCSAN,
BUG: KCSAN: data-race in flush_tlb_batched_pending / try_to_unmap_one
write to 0xffff93f754880bd0 of 1 bytes by task 822 on cpu 6:
try_to_unmap_one+0x59a/0x1ab0
set_tlb_ubc_flush_pending at mm/rmap.c:635
(inlined by) try_to_unmap_one at mm/rmap.c:1538
rmap_walk_anon+0x296/0x650
rmap_walk+0xdf/0x100
try_to_unmap+0x18a/0x2f0
shrink_page_list+0xef6/0x2870
shrink_inactive_list+0x316/0x880
shrink_lruvec+0x8dc/0x1380
shrink_node+0x317/0xd80
balance_pgdat+0x652/0xd90
kswapd+0x396/0x8d0
kthread+0x1e0/0x200
ret_from_fork+0x27/0x50
read to 0xffff93f754880bd0 of 1 bytes by task 6364 on cpu 4:
flush_tlb_batched_pending+0x29/0x90
flush_tlb_batched_pending at mm/rmap.c:682
change_p4d_range+0x5dd/0x1030
change_pte_range at mm/mprotect.c:44
(inlined by) change_pmd_range at mm/mprotect.c:212
(inlined by) change_pud_range at mm/mprotect.c:240
(inlined by) change_p4d_range at mm/mprotect.c:260
change_protection+0x222/0x310
change_prot_numa+0x3e/0x60
task_numa_work+0x219/0x350
task_work_run+0xed/0x140
prepare_exit_to_usermode+0x2cc/0x2e0
ret_from_intr+0x32/0x42
Reported by Kernel Concurrency Sanitizer on:
CPU: 4 PID: 6364 Comm: mtest01 Tainted: G W L 5.5.0-next-20200210+ #5
Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
flush_tlb_batched_pending() is under PTL but the write is not, but
mm->tlb_flush_batched is only a bool type, so the value is unlikely to be
shattered. Thus, mark it as an intentional data race by using the data
race macro.
Link: http://lkml.kernel.org/r/1581450783-8262-1-git-send-email-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/rmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/rmap.c~mm-rmap-annotate-a-data-race-at-tlb_flush_batched
+++ a/mm/rmap.c
@@ -672,7 +672,7 @@ static bool should_defer_flush(struct mm
*/
void flush_tlb_batched_pending(struct mm_struct *mm)
{
- if (mm->tlb_flush_batched) {
+ if (data_race(mm->tlb_flush_batched)) {
flush_tlb_mm(mm);
/*
_
next prev parent reply other threads:[~2020-08-15 0:31 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-15 0:29 incoming Andrew Morton
2020-08-15 0:30 ` [patch 01/39] asm-generic: pgalloc.h: use correct #ifdef to enable pud_alloc_one() Andrew Morton
2020-08-15 0:30 ` [patch 02/39] Revert "mm/vmstat.c: do not show lowmem reserve protection information of empty zone" Andrew Morton
2020-08-15 0:30 ` [patch 03/39] lz4: fix kernel decompression speed Andrew Morton
2020-08-15 0:30 ` [patch 04/39] exec: restore EACCES of S_ISDIR execve() Andrew Morton
2020-08-15 0:30 ` [patch 05/39] selftests/exec: add file type errno tests Andrew Morton
2020-08-15 0:30 ` [patch 06/39] mailmap: add entry for Greg Kurz Andrew Morton
2020-08-15 0:30 ` [patch 07/39] mm: store compound_nr as well as compound_order Andrew Morton
2020-08-15 0:30 ` [patch 08/39] mm: move page-flags include to top of file Andrew Morton
2020-08-15 0:30 ` [patch 09/39] mm: add thp_order Andrew Morton
2020-08-15 0:30 ` [patch 10/39] mm: add thp_size Andrew Morton
2020-08-15 0:30 ` [patch 11/39] mm: replace hpage_nr_pages with thp_nr_pages Andrew Morton
2020-08-15 0:30 ` [patch 12/39] mm: add thp_head Andrew Morton
2020-08-15 0:30 ` [patch 13/39] mm: introduce offset_in_thp Andrew Morton
2020-08-15 0:30 ` [patch 14/39] fs: autofs: delete repeated words in comments Andrew Morton
2020-08-15 0:30 ` [patch 15/39] mm/madvise: pass task and mm to do_madvise Andrew Morton
2020-08-15 0:30 ` [patch 16/39] pid: move pidfd_get_pid() to pid.c Andrew Morton
2020-08-15 0:30 ` [patch 17/39] mm/madvise: introduce process_madvise() syscall: an external memory hinting API Andrew Morton
2020-08-16 8:12 ` Christian Brauner
2020-08-17 15:10 ` Minchan Kim
2020-08-15 0:31 ` [patch 18/39] mm/madvise: check fatal signal pending of target process Andrew Morton
2020-08-15 2:53 ` Linus Torvalds
2020-08-15 4:59 ` Minchan Kim
2020-08-15 14:57 ` Linus Torvalds
2020-08-15 18:34 ` Minchan Kim
2020-08-16 1:43 ` Linus Torvalds
2020-08-16 5:58 ` Minchan Kim
2020-08-15 0:31 ` [patch 19/39] all arch: remove system call sys_sysctl Andrew Morton
2020-08-15 0:31 ` [patch 20/39] mm/kmemleak: silence KCSAN splats in checksum Andrew Morton
2020-08-15 0:31 ` [patch 21/39] mm/frontswap: mark various intentional data races Andrew Morton
2020-08-15 0:31 ` [patch 22/39] mm/page_io: " Andrew Morton
2020-08-15 0:31 ` [patch 23/39] mm/swap_state: " Andrew Morton
2020-08-15 0:31 ` [patch 24/39] mm/filemap.c: fix a data race in filemap_fault() Andrew Morton
2020-08-15 0:31 ` [patch 25/39] mm/swapfile: fix and annotate various data races Andrew Morton
2020-08-15 0:31 ` [patch 26/39] mm/page_counter: fix various data races at memsw Andrew Morton
2020-08-15 0:31 ` [patch 27/39] mm/memcontrol: fix a data race in scan count Andrew Morton
2020-08-15 0:31 ` [patch 28/39] mm/list_lru: fix a data race in list_lru_count_one Andrew Morton
2020-08-15 0:31 ` [patch 29/39] mm/mempool: fix a data race in mempool_free() Andrew Morton
2020-08-15 0:31 ` Andrew Morton [this message]
2020-08-15 0:31 ` [patch 31/39] mm/swap.c: annotate data races for lru_rotate_pvecs Andrew Morton
2020-08-15 0:31 ` [patch 32/39] mm: annotate a data race in page_zonenum() Andrew Morton
2020-08-15 0:31 ` [patch 33/39] include/asm-generic/vmlinux.lds.h: align ro_after_init Andrew Morton
2020-08-15 0:32 ` [patch 34/39] sh: clkfwk: remove r8/r16/r32 Andrew Morton
2020-08-15 0:32 ` [patch 35/39] sh: use generic strncpy() Andrew Morton
2020-08-15 0:32 ` [patch 36/39] iomap: constify ioreadX() iomem argument (as in generic implementation) Andrew Morton
2020-08-15 0:32 ` [patch 37/39] rtl818x: " Andrew Morton
2020-08-15 0:32 ` [patch 38/39] ntb: intel: " Andrew Morton
2020-08-15 0:32 ` [patch 39/39] virtio: pci: " Andrew Morton
2020-08-19 23:09 ` mmotm 2020-08-19-16-09 uploaded Andrew Morton
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