linux/drivers/isdn
Paul Bolle 8d2c3ab444 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 b8b2c7d845
("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 25cad69f21 ("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>
2016-02-19 15:52:41 -05:00
..
act2000 isdn: act200: fix MODULE_PARM_DESC() typo 2016-01-08 13:24:20 -05:00
capi isdn/capi: Use setup_timer 2015-05-31 21:36:37 -07:00
divert
gigaset ser_gigaset: use container_of() instead of detour 2016-02-19 15:52:41 -05:00
hardware mISDN: prevent possible NULL pointer dereference 2016-02-18 14:59:35 -05:00
hisax isdn: Partially revert debug format string usage clean up 2015-11-25 11:49:58 -05:00
hysdn
i4l isdn: remove spellcaster driver 2015-12-01 16:06:44 -05:00
icn arch, drivers: don't include <asm/io.h> directly, use <linux/io.h> instead 2015-08-10 23:07:05 -04:00
isdnloop
mISDN Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-24 06:54:12 -07:00
pcbit
Kconfig
Makefile isdn: remove spellcaster driver 2015-12-01 16:06:44 -05:00