diff options
author | Paul Bolle <pebolle@tiscali.nl> | 2016-02-18 23:29:08 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-02-19 23:52:41 +0300 |
commit | 8d2c3ab4445640957d136caa3629857d63544a2a (patch) | |
tree | e72809a721c5fb5ba5e0e90ee0a9d54175aeec1e /net/unix/diag.c | |
parent | 0b7662cf97ee41af03bc8d4498ff4100d0843338 (diff) | |
download | linux-8d2c3ab4445640957d136caa3629857d63544a2a.tar.xz |
ser_gigaset: use container_of() instead of detour
The purpose of gigaset_device_release() is to kfree() the struct
ser_cardstate that contains our struct device. This is done via a bit of
a detour. First we make our struct device's driver_data point to the
container of our struct ser_cardstate (which is a struct cardstate). In
gigaset_device_release() we then retrieve that driver_data again. And
after that we finally kfree() the struct ser_cardstate that was saved in
the struct cardstate.
All of this can be achieved much easier by using container_of() to get
from our struct device to its container, struct ser_cardstate. Do so.
Note that at the time the detour was implemented commit b8b2c7d845d5
("base/platform: assert that dev_pm_domain callbacks are called
unconditionally") had just entered the tree. That commit disconnected
our platform_device and our platform_driver. These were reconnected
again in v4.5-rc2 through commit 25cad69f21f5 ("base/platform: Fix
platform drivers with no probe callback"). And one of the consequences
of that fix was that it broke the detour via driver_data. That's because
it made __device_release_driver() stop being a NOP for our struct device
and actually do stuff again. One of the things it now does, is setting
our driver_data to NULL. That, in turn, makes it impossible for
gigaset_device_release() to get to our struct cardstate. Which has the
net effect of leaking a struct ser_cardstate at every call of this
driver's tty close() operation. So using container_of() has the
additional benefit of actually working.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/unix/diag.c')
0 files changed, 0 insertions, 0 deletions