media: dvb-usb-v2: gl861: Fix null-ptr-deref in gl861_i2c_master_xfer

In gl861_i2c_master_xfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach gl861_i2c_master_xfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.

Similar commit:
commit 0ed554fd769a
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")

Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: dvb-usb-ids.h: fix an USB PID name

The USB_PID_ALINK_DTU is a Product ID, not a vendor ID.

Fix that.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: docs: move driver-specific info to driver-api

Those documents don't really describe the driver API.

Instead, they contain development-specific information.

Yet, as the main index file describes the content of it as:

"how specific kernel subsystems work
from the point of view of a kernel developer"

It seems to be the better fit.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: dvb-usb-gl861: support I2C read from tuner via demod

Support Friio devices to read from tuner via demod tc90522,
by enabling the config option.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb-usb-v2/gl861: remove an un-used header file

The header contained just internal definitions
and they are not used anymore.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb-usb-v2/gl861: remove device-specific i2c algo

For Friio dvb cards, a distinct I2C algo was provided to support
some "long" I2C messages used in relaying tuner I2C via demod.
Since the other (generic) i2c algo in this module has been patched
to support those messages in a more generic way,
this patch replaces and integrates the device-specific i2c algo
with the generic one and simplifies the code.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: gl861: re-implement I2C adapter logic

Device I2C adapter is capable of writing and reading large messages.
For I2C writes there is 2 methods: simple for max 2 byte messages and
usb_control_msg() with payload data for larger I2C messages. Add I2C
adapter logic which selects suitable method according to message size.
Add also support for plain I2C read.

Cc: Akihiro TSUKADA <tskd08@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: don't do a 31 bit shift on a signed int

On 32-bits archs, a signed integer has 31 bits plus on extra
bit for signal. Due to that, touching the 32th bit with something
like:

int bar = 1 << 31;

has an undefined behavior in C on 32 bit architectures, as it
touches the signal bit. This is warned by cppcheck.

Instead, force the numbers to be unsigned, in order to solve this
issue.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081036.435762997@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

media: usb: Use kmemdup instead of duplicating its function.

kmemdup has implemented the function that kmalloc() + memcpy().
We prefer to kmemdup rather than code opened implementation.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: use strscpy() instead of strlcpy()

The implementation of strscpy() is more robust and safer.

That's now the recommended way to copy NUL terminated strings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb-usb/friio, dvb-usb-v2/gl861: decompose friio and merge with gl861

Friio device contains "gl861" bridge and "tc90522" demod,
for which the separate drivers are already in the kernel.
But friio driver was monolithic and did not use them,
practically copying those features.
This patch decomposes friio driver into sub drivers and
re-uses existing ones, thus reduces some code.

It adds some features to gl861,
to support the friio-specific init/config of the devices
and implement i2c communications to the tuner via demod
with USB vendor requests.

[mchehab+samsung@kernel.org: fix merge conflicts]
Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: gl861: fix probe of dvb_usb_gl861

Probe of dvb_usb_gl861 was working at least with v4.4. Noticed the issue
with v4.13 but according to similar issues the problem started with v4.9.

[ 15.288065] transfer buffer not dma capable
[ 15.288090] WARNING: CPU: 2 PID: 493 at drivers/usb/core/hcd.c:1595 usb_hcd_map_urb_for_dma+0x4e2/0x640
...CUT...
[ 15.288791] dvb_usb_gl861: probe of 3-7:1.0 failed with error -5

Tested with MSI Mega Sky 580 DVB-T Tuner [GL861]

[mchehab+samsung@kernel.org: rebased on the top of upstream]
Cc: stable@vger.kernel.org
Signed-off-by: Mika Båtsman <mika.batsman@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb: point to the location of the old README.dvb-usb file

This file got renamed, but the references still point to the
old place.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>

media: dvb-usb-v2/gl861: ensure USB message buffers DMA'able

i2c message buf might be on stack.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb-usb-v2/gl861: use usleep_range() for short delay

As the kernel doc "timers-howto.txt" reads,
short delay with msleep() can take much longer.
In a case of raspbery-pi platform where CONFIG_HZ_100 was set,
it actually affected the init of Friio devices
since it issues lots of i2c transactions with short delay.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

[media] gl861: use Kernel dev_foo() logging

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] gl861: reset_resume support

It survives now on reset_resume.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

[media] dvb-usb: move it to drivers/media/usb/dvb-usb

As media/dvb will be removed, move it to a proper place.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>