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author | Pingfan Liu <kernelfans@gmail.com> | 2018-07-19 13:14:58 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-26 08:38:04 +0200 |
commit | ab605544f62b5151c2cb276f6771a8c423378926 (patch) | |
tree | 44dbcaec9c21c7447c865d25804b483603e81693 /drivers/i2c | |
parent | f3662e33251057a00354a48df6e7b0fadba7fb34 (diff) |
drivers/base: stop new probing during shutdown
[ Upstream commit 3297c8fc65af5d40501ea7cddff1b195cae57e4e ]
There is a race window in device_shutdown(), which may cause
-1. parent device shut down before child or
-2. no shutdown on a new probing device.
For 1st, taking the following scenario:
device_shutdown new plugin device
list_del_init(parent_dev);
spin_unlock(list_lock);
device_add(child)
probe child
shutdown parent_dev
--> now child is on the tail of devices_kset
For 2nd, taking the following scenario:
device_shutdown new plugin device
device_add(dev)
device_lock(dev);
...
device_unlock(dev);
probe dev
--> now, the new occurred dev has no opportunity to shutdown
To fix this race issue, just prevent the new probing request. With this
logic, device_shutdown() is more similar to dpm_prepare().
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/i2c')
0 files changed, 0 insertions, 0 deletions