Commit Graph

5 Commits

Author SHA1 Message Date
Max Kellermann f17c403af9 media: dvbdev: add a mutex protecting the "mdev" pointer
During destruction, a race condition in
dvb_media_controller_disable_source() can cause a kernel crash,
because the "mdev" pointer has been read successfully while another
task executes dvb_usb_media_device_unregister(), which destroys the
object.  Example for such a crash:

    general protection fault: 0000 [#1] SMP
    CPU: 1 PID: 301 Comm: vdr Not tainted 4.8.1-nuc+ #102
    [142B blob data]
    task: ffff8802301f2040 task.stack: ffff880233728000
    RIP: 0010:[<ffffffff816c296b>]  [<ffffffff816c296b>] dvb_frontend_release+0xcb/0x120
    RSP: 0018:ffff88023372bdd8  EFLAGS: 00010202
    RAX: 001fd55c000000da RBX: ffff880236bad810 RCX: 0000000000000000
    RDX: ffff880235bd81f0 RSI: 0000000000000246 RDI: ffff880235bd81e8
    RBP: ffff88023372be00 R08: 0000000000000000 R09: 0000000000000000
    R10: 0000000000000000 R11: ffff88022f009910 R12: 0000000000000000
    R13: ffff880235a21a80 R14: ffff880235bd8000 R15: ffff880235bb8a78
    FS:  0000000000000000(0000) GS:ffff88023fd00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007f96edd69818 CR3: 0000000002406000 CR4: 00000000001006e0
    Stack:
     ffff88022f009900 0000000000000008 ffff880235bb8a78 ffff8802344fbb20
     ffff880236437b40 ffff88023372be48 ffffffff8117a81e ffff880235bb8a78
     ffff88022f009910 ffff8802335a7400 ffff8802301f2040 ffff88022f009900
    Call Trace:
     [<ffffffff8117a81e>] __fput+0xde/0x1d0
     [<ffffffff8117a949>] ____fput+0x9/0x10
     [<ffffffff810a9fce>] task_work_run+0x7e/0xa0
     [<ffffffff81094bab>] do_exit+0x27b/0xa50
     [<ffffffff810407e3>] ? __do_page_fault+0x1c3/0x430
     [<ffffffff81095402>] do_group_exit+0x42/0xb0
     [<ffffffff8109547f>] SyS_exit_group+0xf/0x10
     [<ffffffff8108bedb>] entry_SYSCALL_64_fastpath+0x13/0x8f
    Code: 31 c9 49 8d be e8 01 00 00 ba 01 00 00 00 be 03 00 00 00 e8 68 2d a0 ff 48 8b 83 10 03 00 00 48 8b 80 88 00 00 00 48 85 c0 74 12 <48> 8b 80 88 02 00 00 48 85 c0 74 06 49 8b 7d
    RIP  [<ffffffff816c296b>] dvb_frontend_release+0xcb/0x120

[mchehab+samsung@kernel.org: fix a Coding Style issue]
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-11 12:09:59 -04:00
Mauro Carvalho Chehab 1980bfa67f media: dvbdev: fix building on ia64
Not sure why, but, on ia64, with Linaro's gcc 7.3 compiler,
using #ifdef (CONFIG_I2C) is not OK.

So, replace it by IS_ENABLED(CONFIG_I2C), in order to fix the
builds there.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-07 04:11:50 -05:00
Mauro Carvalho Chehab 8f569c0b4e media: dvb-core: add helper functions for I2C binding
The dvb_attach()/dvb_detach() methods are ugly hacks designed
to keep using the I2C low-level API. The proper way is to
do I2C bus bindings instead.

Several modules were already converted to use it. Yet,
it is painful to use it, as lots of code need to be
duplicated.

Make it easier by providing two new helper functions:
	- dvb_module_probe()
	- dvb_module_release()

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-06 05:00:31 -05:00
Mauro Carvalho Chehab 4a3fad709b media: fix usage of whitespaces and on indentation
On several places, whitespaces are being used for indentation,
or even at the end of the line.

Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-01-04 13:12:01 -05:00
Mauro Carvalho Chehab fada193559 media: move dvb kAPI headers to include/media
Except for DVB, all media kAPI headers are at include/media.

Move the headers to it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-12-28 13:16:01 -05:00