diff options
| author | Chenwandun <[email protected]> | 2019-10-18 20:20:14 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2019-10-19 06:32:32 -0400 |
| commit | f7daefe4231e57381d92c2e2ad905a899c28e402 (patch) | |
| tree | 067767d5a6b2b6cd00064326605c423ad7edcb54 /tools/perf/util/trace-event-scripting.c | |
| parent | ae8af4388db002bbd1df78ecee7ca31cee78e964 (diff) | |
zram: fix race between backing_dev_show and backing_dev_store
CPU0: CPU1:
backing_dev_show backing_dev_store
...... ......
file = zram->backing_dev;
down_read(&zram->init_lock); down_read(&zram->init_init_lock)
file_path(file, ...); zram->backing_dev = backing_dev;
up_read(&zram->init_lock); up_read(&zram->init_lock);
gets the value of zram->backing_dev too early in backing_dev_show, which
resultin the value being NULL at the beginning, and not NULL later.
backtrace:
d_path+0xcc/0x174
file_path+0x10/0x18
backing_dev_show+0x40/0xb4
dev_attr_show+0x20/0x54
sysfs_kf_seq_show+0x9c/0x10c
kernfs_seq_show+0x28/0x30
seq_read+0x184/0x488
kernfs_fop_read+0x5c/0x1a4
__vfs_read+0x44/0x128
vfs_read+0xa0/0x138
SyS_read+0x54/0xb4
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Chenwandun <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: <[email protected]> [4.14+]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'tools/perf/util/trace-event-scripting.c')
0 files changed, 0 insertions, 0 deletions