USB: serial: make usb_serial_driver::chars_in_buffer return uint

tty_operations::chars_in_buffer is being switched to return uint. Do the
same for usb_serial_driver's chars_in_buffer.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
[ johan: amend commit message ]
Signed-off-by: Johan Hovold <johan@kernel.org>

USB: serial: make usb_serial_driver::write_room return uint

Line disciplines expect a positive value or zero returned from
tty->ops->write_room (invoked by tty_write_room). Both of them are being
updated to return an unsigned int. Switch also
usb_serial_driver::write_room and all its users.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
[ johan: amend commit message, drop unrelated comment change ]
Signed-off-by: Johan Hovold <johan@kernel.org>

USB: serial: add generic support for TIOCSSERIAL

TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.

The closing_wait parameter determines how long to wait for the transfer
buffers to drain during close and the default timeout of 30 seconds may
not be sufficient at low line speeds. In other cases, when for example
flow is stopped, the default timeout may instead be too long.

Add generic support for TIOCSSERIAL and TIOCGSERIAL with handling of the
three common parameters close_delay, closing_wait and line for the
benefit of all USB serial drivers while still allowing drivers to
implement further functionality through the existing callbacks.

This currently includes a few drivers that report their base baud clock
rate even if that is really only of interest when setting custom
divisors through the deprecated ASYNC_SPD_CUST interface; an interface
which only the FTDI driver actually implements.

Some drivers have also been reporting back a fake UART type, something
which should no longer be needed and will be dropped by a follow-on
patch.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

USB: serial: make remove callback return void

All usb_serial drivers return 0 in their remove callbacks and driver
core ignores the value returned by usb_serial_device_remove(). So change
the remove callback to return void and return 0 unconditionally in
usb_serial_device_remove().

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210208143149.963644-2-uwe@kleine-koenig.org
Signed-off-by: Johan Hovold <johan@kernel.org>

USB: serial: option: add ZLP support for 0x1bc7/0x9010

Telit FN980 flashing device 0x1bc7/0x9010 requires zero packet
to be sent if out data size is is equal to the endpoint max size.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
[ johan: switch operands in conditional ]
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

usb_wwan: switch to ->[sg]et_serial()

Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: usb_wwan/option: generalize option_send_setup for other drivers

Only the option driver implements the send_setup callback; it uses the
SET_CONTROL_LINE_STATE request in CDC ACM to generate DTR/RTS signals
on the port. This is not driver-specific though and is needed by other
drivers, so move the function to the usb_wwan driver (with formatting
tweaks), and replace the callback pointer with a flag that enables the
request.

Suggested-by: Bjørn Mork <bjorn@mork.no>
Suggested-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: Johan Hovold <johan@kernel.org>

USB: usb_wwan: do not resume I/O on closing ports

Use tty-port initialised flag rather than private flag to determine when
port is closing down.

Since the tty-port flag is set prior to dropping DTR/RTS (when HUPCL is
set) this avoid submitting the read urbs when resuming the interface in
dtr_rts() only to immediately kill them again in shutdown().

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: usb_wwan: remove bogus function prototype

The usb_wwan_send_setup() function has never existed.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: usb_wwan: remove unimplemented set_termios

The driver does not implement set_termios so the operation can be left
unset (tty will do the tty_termios_copy_hw for us).

Note that the send_setup call is bogus as it really only sets DTR/RTS
to their current values.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: usb_wwan: fix remote wakeup

Make sure that needs_remote_wake up is always set when there are open
ports.

Currently close() would unconditionally set needs_remote_wakeup to 0
even though there might still be open ports. This could lead to blocked
input and possibly dropped data on devices that do not support remote
wakeup (and which must therefore not be runtime suspended while open).

Add an open_ports counter (protected by the susp_lock) and only clear
needs_remote_wakeup when the last port is closed.

Note that there are currently no multi-port drivers using the usb_wwan
implementation.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: usb-wwan: fix multiple memory leaks in error paths

Fix port-data memory leak in usb-serial probe error path by moving port
data allocation to port_probe.

Since commit a1028f0abf ("usb: usb_wwan: replace release and disconnect
with a port_remove hook") port data is deallocated in port_remove. This
leaves a possibility for memory leaks if usb-serial probe fails after
attach but before the port in question has been successfully registered.

Note that this patch also fixes two additional memory leaks in the error
path of attach should port initialisation fail for any port as the urbs
were never freed and neither was the data of any of the successfully
initialised ports.

Compile-only tested.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: usb_wwan: replace release and disconnect with a port_remove hook

Doing port specific cleanup in the .port_remove hook is a
lot simpler and safer than doing it in the USB driver
.release or .disconnect methods. The removal of the port
from the usb-serial bus will happen before the USB driver
cleanup, so we must be careful about accessing port specific
driver data from any USB driver functions.

This problem surfaced after the commit

0998d0631 device-core: Ensure drvdata = NULL when no driver is bound

which turned the previous unsafe access into a reliable NULL
pointer dereference.

Fixes the following Oops:

[ 243.148471] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 243.148508] IP: [<ffffffffa0468527>] stop_read_write_urbs+0x37/0x80 [usb_wwan]
[ 243.148556] PGD 79d60067 PUD 79d61067 PMD 0
[ 243.148590] Oops: 0000 [#1] SMP
[ 243.148617] Modules linked in: sr_mod cdrom qmi_wwan usbnet option cdc_wdm usb_wwan usbserial usb_storage uas fuse af_packet ip6table_filter ip6_tables iptable_filter ip_tables x_tables tun edd
cpufreq_conservative cpufreq_userspace cpufreq_powersave snd_pcm_oss snd_mixer_oss acpi_cpufreq snd_seq mperf snd_seq_device coretemp arc4 sg hp_wmi sparse_keymap uvcvideo videobuf2_core
videodev videobuf2_vmalloc videobuf2_memops rtl8192ce rtl8192c_common rtlwifi joydev pcspkr microcode mac80211 i2c_i801 lpc_ich r8169 snd_hda_codec_idt cfg80211 snd_hda_intel snd_hda_codec rfkill
snd_hwdep snd_pcm wmi snd_timer ac snd soundcore snd_page_alloc battery uhci_hcd i915 drm_kms_helper drm i2c_algo_bit ehci_hcd thermal usbcore video usb_common button processor thermal_sys
[ 243.149007] CPU 1
[ 243.149027] Pid: 135, comm: khubd Not tainted 3.5.0-rc7-next-20120720-1-vanilla #1 Hewlett-Packard HP Mini 110-3700 /1584
[ 243.149072] RIP: 0010:[<ffffffffa0468527>] [<ffffffffa0468527>] stop_read_write_urbs+0x37/0x80 [usb_wwan]
[ 243.149118] RSP: 0018:ffff880037e75b30 EFLAGS: 00010286
[ 243.149133] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88005912aa28
[ 243.149150] RDX: ffff88005e95f028 RSI: 0000000000000000 RDI: ffff88005f7c1a10
[ 243.149166] RBP: ffff880037e75b60 R08: 0000000000000000 R09: ffffffff812cea90
[ 243.149182] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88006539b440
[ 243.149198] R13: ffff88006539b440 R14: 0000000000000000 R15: 0000000000000000
[ 243.149216] FS: 0000000000000000(0000) GS:ffff88007ee80000(0000) knlGS:0000000000000000
[ 243.149233] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 243.149248] CR2: 0000000000000000 CR3: 0000000079fe0000 CR4: 00000000000007e0
[ 243.149264] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 243.149280] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 243.149298] Process khubd (pid: 135, threadinfo ffff880037e74000, task ffff880037d40600)
[ 243.149313] Stack:
[ 243.149323] ffff880037e75b40 ffff88006539b440 ffff8800799bc830 ffff88005f7c1800
[ 243.149348] 0000000000000001 ffff88006539b448 ffff880037e75b70 ffffffffa04685e9
[ 243.149371] ffff880037e75bc0 ffffffffa0473765 ffff880037354988 ffff88007b594800
[ 243.149395] Call Trace:
[ 243.149419] [<ffffffffa04685e9>] usb_wwan_disconnect+0x9/0x10 [usb_wwan]
[ 243.149447] [<ffffffffa0473765>] usb_serial_disconnect+0xd5/0x120 [usbserial]
[ 243.149511] [<ffffffffa0046b48>] usb_unbind_interface+0x58/0x1a0 [usbcore]
[ 243.149545] [<ffffffff8139ebd7>] __device_release_driver+0x77/0xe0
[ 243.149567] [<ffffffff8139ec67>] device_release_driver+0x27/0x40
[ 243.149587] [<ffffffff8139e5cf>] bus_remove_device+0xdf/0x150
[ 243.149608] [<ffffffff8139bc78>] device_del+0x118/0x1a0
[ 243.149661] [<ffffffffa0044590>] usb_disable_device+0xb0/0x280 [usbcore]
[ 243.149718] [<ffffffffa003c6fd>] usb_disconnect+0x9d/0x140 [usbcore]
[ 243.149770] [<ffffffffa003da7d>] hub_port_connect_change+0xad/0x8a0 [usbcore]
[ 243.149825] [<ffffffffa0043bf5>] ? usb_control_msg+0xe5/0x110 [usbcore]
[ 243.149878] [<ffffffffa003e6e3>] hub_events+0x473/0x760 [usbcore]
[ 243.149931] [<ffffffffa003ea05>] hub_thread+0x35/0x1d0 [usbcore]
[ 243.149955] [<ffffffff81061960>] ? add_wait_queue+0x60/0x60
[ 243.150004] [<ffffffffa003e9d0>] ? hub_events+0x760/0x760 [usbcore]
[ 243.150026] [<ffffffff8106133e>] kthread+0x8e/0xa0
[ 243.150047] [<ffffffff8157ec04>] kernel_thread_helper+0x4/0x10
[ 243.150068] [<ffffffff810612b0>] ? flush_kthread_work+0x120/0x120
[ 243.150088] [<ffffffff8157ec00>] ? gs_change+0xb/0xb
[ 243.150101] Code: fd 41 54 53 48 83 ec 08 80 7f 1a 00 74 57 49 89 fc 31 db 90 49 8b 7c 24 20 45 31 f6 48 81 c7 10 02 00 00 e8 bc 64 f3 e0 49 89 c7 <4b> 8b 3c 37 49 83 c6 08 e8 4c a5 bd ff 49 83 fe 20
75 ed 45 30
[ 243.150257] RIP [<ffffffffa0468527>] stop_read_write_urbs+0x37/0x80 [usb_wwan]
[ 243.150282] RSP <ffff880037e75b30>
[ 243.150294] CR2: 0000000000000000
[ 243.177170] ---[ end trace fba433d9015ffb8c ]---

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Thomas Schäfer <tschaefer@t-online.de>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove filp from the USB tty ioctls

We don't use it so we can trim it from here as we try and stamp the file
object dependencies out of the serial code.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

tiocmset: kill the file pointer argument

Doing tiocmget was such fun we should do tiocmset as well for the same
reasons

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

tiocmget: kill off the passing of the struct file

We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

usb-wwan: implement TIOCGSERIAL and TIOCSSERIAL to avoid blocking close(2)

Some devices (ex ZTE 2726) simply don't respond at all when data is sent
to some of their USB interfaces. The data gets stuck in the TTYs queue
and sits there until close(2), which them blocks because closing_wait
defaults to 30 seconds (even though the fd is O_NONBLOCK). This is
rarely desired. Implement the standard mechanism to adjust closing_wait
and let applications handle it how they want to.

Signed-off-by: Dan Williams <dcbw@redhat.com>

usb serial: Add generic USB wwan support

The generic USB serial code is ill-suited for high-speed USB wwan devices,
resulting in the option driver. However, other non-option devices may also
gain similar benefits from not using the generic code. Factorise out the
non-option specific code from the option driver and make it available to
other users.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>