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 23/39] mm/swap_state: mark various intentional data races
Date: Fri, 14 Aug 2020 17:31:24 -0700 [thread overview]
Message-ID: <20200815003124.3RbdiMBNy%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200814172939.55d6d80b6e21e4241f1ee1f3@linux-foundation.org>
From: Qian Cai <cai@lca.pw>
Subject: mm/swap_state: mark various intentional data races
swap_cache_info.* could be accessed concurrently as noticed by
KCSAN,
BUG: KCSAN: data-race in lookup_swap_cache / lookup_swap_cache
write to 0xffffffff85517318 of 8 bytes by task 94138 on cpu 101:
lookup_swap_cache+0x12e/0x460
lookup_swap_cache at mm/swap_state.c:322
do_swap_page+0x112/0xeb0
__handle_mm_fault+0xc7a/0xd00
handle_mm_fault+0xfc/0x2f0
do_page_fault+0x263/0x6f9
page_fault+0x34/0x40
read to 0xffffffff85517318 of 8 bytes by task 91655 on cpu 100:
lookup_swap_cache+0x117/0x460
lookup_swap_cache at mm/swap_state.c:322
shmem_swapin_page+0xc7/0x9e0
shmem_getpage_gfp+0x2ca/0x16c0
shmem_fault+0xef/0x3c0
__do_fault+0x9e/0x220
do_fault+0x4a0/0x920
__handle_mm_fault+0xc69/0xd00
handle_mm_fault+0xfc/0x2f0
do_page_fault+0x263/0x6f9
page_fault+0x34/0x40
Reported by Kernel Concurrency Sanitizer on:
CPU: 100 PID: 91655 Comm: systemd-journal Tainted: G W O L 5.5.0-next-20200204+ #6
Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
write to 0xffffffff8d717308 of 8 bytes by task 11365 on cpu 87:
__delete_from_swap_cache+0x681/0x8b0
__delete_from_swap_cache at mm/swap_state.c:178
read to 0xffffffff8d717308 of 8 bytes by task 11275 on cpu 53:
__delete_from_swap_cache+0x66e/0x8b0
__delete_from_swap_cache at mm/swap_state.c:178
Both the read and write are done as lockless. Since swap_cache_info.*
are only used to print out counter information, even if any of them
missed a few incremental due to data races, it will be harmless, so just
mark it as an intentional data race using the data_race() macro.
While at it, fix a checkpatch.pl warning,
WARNING: Single statement macros should not use a do {} while (0) loop
Link: http://lkml.kernel.org/r/20200207003715.1578-1-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/swap_state.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/swap_state.c~mm-swap_state-mark-various-intentional-data-races
+++ a/mm/swap_state.c
@@ -57,8 +57,8 @@ static bool enable_vma_readahead __read_
#define GET_SWAP_RA_VAL(vma) \
(atomic_long_read(&(vma)->swap_readahead_info) ? : 4)
-#define INC_CACHE_INFO(x) do { swap_cache_info.x++; } while (0)
-#define ADD_CACHE_INFO(x, nr) do { swap_cache_info.x += (nr); } while (0)
+#define INC_CACHE_INFO(x) data_race(swap_cache_info.x++)
+#define ADD_CACHE_INFO(x, nr) data_race(swap_cache_info.x += (nr))
static struct {
unsigned long add_total;
_
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 ` Andrew Morton [this message]
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 ` [patch 30/39] mm/rmap: annotate a data race at tlb_flush_batched Andrew Morton
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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