Revert "media: dvb-core: Fix use-after-free on race condition at dvb_frontend"

As reported by Thomas Voegtle <tv@lio96.de>, sometimes a DVB card does
not initialize properly booting Linux 6.4-rc4. This is not always, maybe
in 3 out of 4 attempts.

After double-checking, the root cause seems to be related to the
UAF fix, which is causing a race issue:

[ 26.332149] tda10071 7-0005: found a 'NXP TDA10071' in cold state, will try to load a firmware
[ 26.340779] tda10071 7-0005: downloading firmware from file 'dvb-fe-tda10071.fw'
[ 989.277402] INFO: task vdr:743 blocked for more than 491 seconds.
[ 989.283504] Not tainted 6.4.0-rc5-i5 #249
[ 989.288036] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 989.295860] task:vdr state:D stack:0 pid:743 ppid:711 flags:0x00004002
[ 989.295865] Call Trace:
[ 989.295867] <TASK>
[ 989.295869] __schedule+0x2ea/0x12d0
[ 989.295877] ? asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 989.295881] schedule+0x57/0xc0
[ 989.295884] schedule_preempt_disabled+0xc/0x20
[ 989.295887] __mutex_lock.isra.16+0x237/0x480
[ 989.295891] ? dvb_get_property.isra.10+0x1bc/0xa50
[ 989.295898] ? dvb_frontend_stop+0x36/0x180
[ 989.338777] dvb_frontend_stop+0x36/0x180
[ 989.338781] dvb_frontend_open+0x2f1/0x470
[ 989.338784] dvb_device_open+0x81/0xf0
[ 989.338804] ? exact_lock+0x20/0x20
[ 989.338808] chrdev_open+0x7f/0x1c0
[ 989.338811] ? generic_permission+0x1a2/0x230
[ 989.338813] ? link_path_walk.part.63+0x340/0x380
[ 989.338815] ? exact_lock+0x20/0x20
[ 989.338817] do_dentry_open+0x18e/0x450
[ 989.374030] path_openat+0xca5/0xe00
[ 989.374031] ? terminate_walk+0xec/0x100
[ 989.374034] ? path_lookupat+0x93/0x140
[ 989.374036] do_filp_open+0xc0/0x140
[ 989.374038] ? __call_rcu_common.constprop.91+0x92/0x240
[ 989.374041] ? __check_object_size+0x147/0x260
[ 989.374043] ? __check_object_size+0x147/0x260
[ 989.374045] ? alloc_fd+0xbb/0x180
[ 989.374048] ? do_sys_openat2+0x243/0x310
[ 989.374050] do_sys_openat2+0x243/0x310
[ 989.374052] do_sys_open+0x52/0x80
[ 989.374055] do_syscall_64+0x5b/0x80
[ 989.421335] ? __task_pid_nr_ns+0x92/0xa0
[ 989.421337] ? syscall_exit_to_user_mode+0x20/0x40
[ 989.421339] ? do_syscall_64+0x67/0x80
[ 989.421341] ? syscall_exit_to_user_mode+0x20/0x40
[ 989.421343] ? do_syscall_64+0x67/0x80
[ 989.421345] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 989.421348] RIP: 0033:0x7fe895d067e3
[ 989.421349] RSP: 002b:00007fff933c2ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
[ 989.421351] RAX: ffffffffffffffda RBX: 00007fff933c2c10 RCX: 00007fe895d067e3
[ 989.421352] RDX: 0000000000000802 RSI: 00005594acdce160 RDI: 00000000ffffff9c
[ 989.421353] RBP: 0000000000000802 R08: 0000000000000000 R09: 0000000000000000
[ 989.421353] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
[ 989.421354] R13: 00007fff933c2ca0 R14: 00000000ffffffff R15: 00007fff933c2c90
[ 989.421355] </TASK>

This reverts commit 6769a0b7ee0c3b31e1b22c3fadff2bfb642de23f.

Fixes: 6769a0b7ee0c ("media: dvb-core: Fix use-after-free on race condition at dvb_frontend")
Link: https://lore.kernel.org/all/da5382ad-09d6-20ac-0d53-611594b30861@lio96.de/
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: dvb-core: Fix use-after-free on race condition at dvb_frontend

If the device node of dvb_frontend is open() and the device is
disconnected, many kinds of UAFs may occur when calling close()
on the device node.

The root cause of this is that wake_up() for dvbdev->wait_queue
is implemented in the dvb_frontend_release() function, but
wait_event() is not implemented in the dvb_frontend_stop() function.

So, implement wait_event() function in dvb_frontend_stop() and
add 'remove_mutex' which prevents race condition for 'fe->exit'.

[mchehab: fix a couple of checkpatch warnings and some mistakes at the error handling logic]

Link: https://lore.kernel.org/linux-media/20221117045925.14297-2-imv4bel@gmail.com
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: media dvb_frontend: add suspend and resume callbacks to dvb_frontend_ops

While dvb_tuner_ops already has dedicated suspend and resume callbacks,
dvb_frontend_ops currently does not have them. Add those callbacks and
use them for suspend and resume. If they are not set, the old behavior
of calling sleep or init is used.

This allows dvb_frontend drivers to handle resume differently from init,
and suspend differently from sleep. No change is required for drivers
not needing this functionality.

Link: https://lore.kernel.org/linux-media/20210418001204.7453-2-kernel@tuxforce.de

Cc: Lukas Middendorf <kernel@tuxforce.de>, Antti Palosaari <crope@iki.fi>, Mauro Carvalho Chehab <mchehab@kernel.org>, Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Lukas Middendorf <kernel@tuxforce.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: dvb_frontend.h: Fix shifting signed 32-bit value problem

Fix DVBFE_ALGO_RECOVERY and DVBFE_ALGO_SEARCH_ERROR use BIT macro which
fixes undefined behavior error by certain compilers.

Also changed all other bit shifted definitions to use macro for better
readability.

Signed-off-by: Luke Nowakowski-Krijger <lnowakow@eng.ucsd.edu>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: include: fix several typos

Use codespell to fix lots of typos over frontends.

Manually verified to avoid false-positives.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb: represent min/max/step/tolerance freqs in Hz

Right now, satellite frontend drivers specify frequencies in kHz,
while terrestrial/cable ones specify in Hz. That's confusing
for developers.

However, the main problem is that universal frontends capable
of handling both satellite and non-satelite delivery systems
are appearing. We end by needing to hack the drivers in
order to support such hybrid frontends.

So, convert everything to specify frontend frequencies in Hz.

Tested-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb: convert tuner_info frequencies to Hz

Right now, satellite tuner drivers specify frequencies in kHz,
while terrestrial/cable ones specify in Hz. That's confusing
for developers.

However, the main problem is that universal tuners capable
of handling both satellite and non-satelite delivery systems
are appearing. We end by needing to hack the drivers in
order to support such hybrid tuners.

So, convert everything to specify tuner frequencies in Hz.

Plese notice that a similar patch is also needed for frontends.

Tested-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
Acked-by: Michael Büsch <m@bues.ch>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

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>

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>