A null pointer dereference can happen when attempting to access the
"gsm->receive()" function in gsmld_receive_buf(). Currently, the code
assumes that gsm->recieve is only called after MUX activation.
Since the gsmld_receive_buf() function can be accessed without the need to
initialize the MUX, the gsm->receive() function will not be set and a
NULL pointer dereference will occur.
Fix this by avoiding the call to "gsm->receive()" in case the function is
not initialized by adding a sanity check.
Call Trace:
<TASK>
gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861
tiocsti drivers/tty/tty_io.c:2293 [inline]
tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Link: https://syzkaller.appspot.com/bug?id=bdf035c61447f8c6e0e6920315d577cb5cc35ac5
Fixes: 01aecd9171 ("tty: n_gsm: fix tty registration before control channel open")
Cc: stable <stable@kernel.org>
Reported-and-tested-by: syzbot+e3563f0c94e188366dbb@syzkaller.appspotmail.com
Signed-off-by: Mazin Al Haddad <mazinalhaddad05@gmail.com>
Link: https://lore.kernel.org/r/20220814015211.84180-1-mazinalhaddad05@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There should be no reason to adjust old ktermios which is going to get
discarded anyway.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220816115739.10928-9-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gsmld_poll() currently fails to handle the following corner cases correctly:
- remote party closed the associated tty
Add the missing checks and map those to EPOLLHUP.
Reorder the checks to group them by their reaction.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current implementation constipates all transmission paths during flow
control except for flow control frames. However, these may not be located
at the beginning of the transmission queue of the control channel.
Ensure that flow control frames in the transmission queue for the control
channel are always handled even if constipated by skipping through other
messages.
Fixes: 0af021678d ("tty: n_gsm: fix deadlock and link starvation in outgoing data path")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220707113223.3685-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.3.3 defines the DM response. There exists
no DM command. However, the current implementation incorrectly sends DM as
command in case of unexpected UIH frames in gsm_queue().
Correct this behavior by always sending DM as response.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220707113223.3685-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.7.3 states that the valid range for the
maximum number of retransmissions (N2) is from 0 to 255 (both including).
gsm_dlci_t1() handles this number incorrectly by performing N2 - 1
retransmission attempts. Setting N2 to zero results in more than 255
retransmission attempts.
Fix gsm_dlci_t1() to comply with 3GPP 27.010.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220707113223.3685-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Within gsm_activate_mux() all timers and locks are initiated before the
actual resource for the control channel is allocated. This can lead to race
conditions.
Allocate the control channel DLCI object first to avoid race conditions.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701122332.2039-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current implementation queues up new control and user packets as needed
and processes this queue down to the ldisc in the same code path.
That means that the upper and the lower layer are hard coupled in the code.
Due to this deadlocks can happen as seen below while transmitting data,
especially during ldisc congestion. Furthermore, the data channels starve
the control channel on high transmission load on the ldisc.
Introduce an additional control channel data queue to prevent timeouts and
link hangups during ldisc congestion. This is being processed before the
user channel data queue in gsm_data_kick(), i.e. with the highest priority.
Put the queue to ldisc data path into a workqueue and trigger it whenever
new data has been put into the transmission queue. Change
gsm_dlci_data_sweep() accordingly to fill up the transmission queue until
TX_THRESH_HI. This solves the locking issue, keeps latency low and provides
good performance on high data load.
Note that now all packets from a DLCI are removed from the internal queue
if the associated DLCI was closed. This ensures that no data is sent by the
introduced write task to an already closed DLCI.
BUG: spinlock recursion on CPU#0, test_v24_loop/124
lock: serial8250_ports+0x3a8/0x7500, .magic: dead4ead, .owner: test_v24_loop/124, .owner_cpu: 0
CPU: 0 PID: 124 Comm: test_v24_loop Tainted: G O 5.18.0-rc2 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0x34/0x44
do_raw_spin_lock+0x76/0xa0
_raw_spin_lock_irqsave+0x72/0x80
uart_write_room+0x3b/0xc0
gsm_data_kick+0x14b/0x240 [n_gsm]
gsmld_write_wakeup+0x35/0x70 [n_gsm]
tty_wakeup+0x53/0x60
tty_port_default_wakeup+0x1b/0x30
serial8250_tx_chars+0x12f/0x220
serial8250_handle_irq.part.0+0xfe/0x150
serial8250_default_handle_irq+0x48/0x80
serial8250_interrupt+0x56/0xa0
__handle_irq_event_percpu+0x78/0x1f0
handle_irq_event+0x34/0x70
handle_fasteoi_irq+0x90/0x1e0
__common_interrupt+0x69/0x100
common_interrupt+0x48/0xc0
asm_common_interrupt+0x1e/0x40
RIP: 0010:__do_softirq+0x83/0x34e
Code: 2a 0a ff 0f b7 ed c7 44 24 10 0a 00 00 00 48 c7 c7 51 2a 64 82 e8 2d
e2 d5 ff 65 66 c7 05 83 af 1e 7e 00 00 fb b8 ff ff ff ff <49> c7 c2 40 61
80 82 0f bc c5 41 89 c4 41 83 c4 01 0f 84 e6 00 00
RSP: 0018:ffffc90000003f98 EFLAGS: 00000286
RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff82642a51 RDI: ffffffff825bb5e7
RBP: 0000000000000200 R08: 00000008de3271a8 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000030 R14: 0000000000000000 R15: 0000000000000000
? __do_softirq+0x73/0x34e
irq_exit_rcu+0xb5/0x100
common_interrupt+0xa4/0xc0
</IRQ>
<TASK>
asm_common_interrupt+0x1e/0x40
RIP: 0010:_raw_spin_unlock_irqrestore+0x2e/0x50
Code: 00 55 48 89 fd 48 83 c7 18 53 48 89 f3 48 8b 74 24 10 e8 85 28 36 ff
48 89 ef e8 cd 58 36 ff 80 e7 02 74 01 fb bf 01 00 00 00 <e8> 3d 97 33 ff
65 8b 05 96 23 2b 7e 85 c0 74 03 5b 5d c3 0f 1f 44
RSP: 0018:ffffc9000020fd08 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000246 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff8257fd74 RDI: 0000000000000001
RBP: ffff8880057de3a0 R08: 00000008de233000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000100 R14: 0000000000000202 R15: ffff8880057df0b8
? _raw_spin_unlock_irqrestore+0x23/0x50
gsmtty_write+0x65/0x80 [n_gsm]
n_tty_write+0x33f/0x530
? swake_up_all+0xe0/0xe0
file_tty_write.constprop.0+0x1b1/0x320
? n_tty_flush_buffer+0xb0/0xb0
new_sync_write+0x10c/0x190
vfs_write+0x282/0x310
ksys_write+0x68/0xe0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3e5e35c15c
Code: 8b 7c 24 08 89 c5 e8 c5 ff ff ff 89 ef 89 44 24 08 e8 58 bc 02 00 8b
44 24 08 48 83 c4 10 5d c3 48 63 ff b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff
ff 76 10 48 8b 15 fd fc 05 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffcee77cd18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffcee77cd70 RCX: 00007f3e5e35c15c
RDX: 0000000000000100 RSI: 00007ffcee77cd90 RDI: 0000000000000003
RBP: 0000000000000100 R08: 0000000000000000 R09: 7efefefefefefeff
R10: 00007f3e5e3bddeb R11: 0000000000000246 R12: 00007ffcee77ce8f
R13: 0000000000000001 R14: 000056214404e010 R15: 00007ffcee77cd90
</TASK>
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701122332.2039-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function may be used by the user directly and also by the n_gsm
internal functions. They can lead into a race condition which results in
interleaved frames if both are writing at the same time. The receiving side
is not able to decode those interleaved frames correctly.
Add a lock around the low side tty write to avoid race conditions and frame
interleaving between user originated writes and n_gsm writes.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701061652.39604-9-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the current implementation control packets are re-transmitted even if
the control channel closed down during T2. This is wrong.
Check whether the control channel is open before re-transmitting any
packets. Note that control channel open/close is handled by T1 and not T2
and remains unaffected by this.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701061652.39604-7-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.4.6.3.6 states that FCoff stops the
transmission on all channels except the control channel. This is already
implemented in gsm_data_kick(). However, chapter 5.4.8.1 explains that this
shall result in the same behavior as software flow control on the ldisc in
advanced option mode. That means only flow control frames shall be sent
during flow off. The current implementation does not consider this case.
Change gsm_data_kick() to send only flow control frames if constipated to
abide the standard. gsm_read_ea_val() and gsm_is_flow_ctrl_msg() are
introduced as helper functions for this.
It is planned to use gsm_read_ea_val() in later code cleanups for other
functions, too.
Fixes: c01af4fec2 ("n_gsm : Flow control handling in Mux driver")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701061652.39604-5-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current implementation does not handle the situation that no data is in
the internal queue and needs to be sent out while the user tty fifo is
full.
Add a timer that moves more data from user tty down to the internal queue
which is then serialized on the ldisc. This timer is triggered if no data
was moved from a user tty to the internal queue within 10 * T1.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701061652.39604-4-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1) The function drains the fifo for the given user tty/DLCI without
considering 'TX_THRESH_HI' and different to gsm_dlci_data_output_framed(),
which moves only one packet from the user side to the internal transmission
queue. We can only handle one packet at a time here if we want to allow
DLCI priority handling in gsm_dlci_data_sweep() to avoid link starvation.
2) Furthermore, the additional header octet from convergence layer type 2
is not counted against MTU. It is part of the UI/UIH frame message which
needs to be limited to MTU. Hence, it is wrong not to consider this octet.
3) Finally, the waiting user tty is not informed about freed space in its
send queue.
Take at most one packet worth of data out of the DLCI fifo to fix 1).
Limit the max user data size per packet to MTU - 1 in case of convergence
layer type 2 to leave space for the control signal octet which is added in
the later part of the function. This fixes 2).
Add tty_port_tty_wakeup() to wake up the user tty if new write space has
been made available to fix 3).
Fixes: 268e526b93 ("tty/n_gsm: avoid fifo overflow in gsm_dlci_data_output")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701061652.39604-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current implementation registers/deregisters the user ttys at mux
attach/detach. That means that the user devices are available before any
control channel is open. However, user channel initialization requires an
open control channel. Furthermore, the user is not informed if the mux
restarts due to configuration changes.
Put the registration/deregistration procedure into separate function to
improve readability.
Move registration to mux activation and deregistration to mux cleanup to
keep the user devices only open as long as a control channel exists. The
user will be informed via the device driver if the mux was reconfigured in
a way that required a mux re-activation.
This makes it necessary to add T2 initialization to gsmld_open() for the
ldisc open code path (not the reconfiguration code path) to avoid deletion
of an uninitialized T2 at mux cleanup.
Fixes: d50f6dcaf2 ("tty: n_gsm: expose gsmtty device nodes at ldisc open time")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701061652.39604-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After setting up the control channel on both sides the responder side may
want to open a virtual tty to listen on until the initiator starts an
application on a user channel. The current implementation allows the
open() but no other operation, like termios. These fail with EINVAL.
The responder sided application has no means to detect an open by the
initiator sided application this way. And the initiator sided applications
usually expect the responder sided application to listen on the user
channel upon open.
Set the user channel into half-open state on responder side once a user
application opens the virtual tty to allow IO operations on it.
Furthermore, keep the user channel constipated until the initiator side
opens it to give the responder sided application the chance to detect the
new connection and to avoid data loss if the responder sided application
starts sending before the user channel is open.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220701061652.39604-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dan Carpenter <dan.carpenter@oracle.com> reported the following Smatch
warning:
drivers/tty/n_gsm.c:720 gsm_data_kick()
warn: sleeping in atomic context
This is because gsm_control_message() is holding a spin lock so
gsm_hex_dump_bytes() needs to use GFP_ATOMIC instead of GFP_KERNEL.
Fixes: 925ea0fa52 ("tty: n_gsm: Fix packet data hex dump output")
Cc: stable <stable@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20220523155052.57129-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The module param debug for n_gsm uses KERN_INFO level, but the hexdump
now uses KERN_DEBUG level. This started after commit 091cb0994e
("lib/hexdump: make print_hex_dump_bytes() a nop on !DEBUG builds").
We now use dynamic_hex_dump() unless DEBUG is set.
This causes no packets to be seen with modprobe n_gsm debug=0x1f unlike
earlier. Let's fix this by adding gsm_hex_dump_bytes() that calls
print_hex_dump() with KERN_INFO to match what n_gsm is doing with the
other debug related output.
Fixes: 091cb0994e ("lib/hexdump: make print_hex_dump_bytes() a nop on !DEBUG builds")
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20220512131506.1216-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gsmtty_write() does not prevent the user to use the full fifo size of 4096
bytes as allocated in gsm_dlci_alloc(). However, gsmtty_write_room() tries
to limit the return value by 'TX_SIZE' and returns a negative value if the
fifo has more than 'TX_SIZE' bytes stored. This is obviously wrong as
'TX_SIZE' is defined as 512.
Define 'TX_SIZE' to the fifo size and use it accordingly for allocation to
keep the current behavior. Return the correct remaining size of the fifo in
gsmtty_write_room() via kfifo_avail().
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220504081733.3494-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current implementation activates the mux if it was restarted and opens
the control channel if the mux was previously closed and we are now acting
as initiator instead of responder, which is the default setting.
This has two issues.
1) No mux is activated if we keep all default values and only switch to
initiator. The control channel is not allocated but will be opened next
which results in a NULL pointer dereference.
2) Switching the configuration after it was once configured while keeping
the initiator value the same will not reopen the control channel if it was
closed due to parameter incompatibilities. The mux remains dead.
Fix 1) by always activating the mux if it is dead after configuration.
Fix 2) by always opening the control channel after mux activation.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220504081733.3494-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'len' is decreased after each octet that has its EA bit set to 0, which
means that the value is encoded with additional octets. However, the final
octet does not decreases 'len' which results in 'len' being one byte too
long. A buffer over-read may occur in tty_insert_flip_string() as it tries
to read one byte more than the passed content size of 'data'.
Decrease 'len' also for the final octet which has the EA bit set to 1 to
write the correct number of bytes from the internal receive buffer to the
virtual tty.
Fixes: 2e124b4a39 ("TTY: switch tty_flip_buffer_push")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220504081733.3494-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'size' may be used uninitialized in gsm_dlci_modem_output() if called with
an adaption that is neither 1 nor 2. The function is currently only called
by gsm_modem_upd_via_data() and only for adaption 2.
Properly handle every invalid case by returning -EINVAL to silence the
compiler warning and avoid future regressions.
Fixes: c19ffe00fe ("tty: n_gsm: fix invalid use of MSC in advanced option")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220425104726.7986-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.4.8.1 states that XON/XOFF characters
shall be used instead of Fcon/Fcoff command in advanced option mode to
handle flow control. Chapter 5.4.8.2 describes how XON/XOFF characters
shall be handled. Basic option mode only used Fcon/Fcoff commands and no
XON/XOFF characters. These are treated as data bytes here.
The current implementation uses the gsm_mux field 'constipated' to handle
flow control from the remote peer and the gsm_dlci field 'constipated' to
handle flow control from each DLCI. The later is unrelated to this patch.
The gsm_mux field is correctly set for Fcon/Fcoff commands in
gsm_control_message(). However, the same is not true for XON/XOFF
characters in gsm1_receive().
Disable software flow control handling in the tty to allow explicit
handling by n_gsm.
Add the missing handling in advanced option mode for gsm_mux in
gsm1_receive() to comply with the standard.
This patch depends on the following commit:
Commit 8838b2af23 ("tty: n_gsm: fix SW flow control encoding/handling")
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.4.6.3.7 states that the Modem Status
Command (MSC) shall only be used if the basic option was chosen.
The current implementation uses MSC frames even if advanced option was
chosen to inform the peer about modem line state updates. A standard
conform peer may choose to discard these frames in advanced option mode.
Furthermore, gsmtty_modem_update() is not part of the 'tty_operations'
functions despite its name.
Rename gsmtty_modem_update() to gsm_modem_update() to clarify this. Split
its function into gsm_modem_upd_via_data() and gsm_modem_upd_via_msc()
depending on the encoding and adaption. Introduce gsm_dlci_modem_output()
as adaption of gsm_dlci_data_output() to encode and queue empty frames in
advanced option mode. Use it in gsm_modem_upd_via_data().
gsm_modem_upd_via_msc() is based on the initial gsmtty_modem_update()
function which used only MSC frames to update modem states.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dynamic virtual tty registration was introduced to allow the user to handle
these cases with uevent rules. The following commits relate to this:
Commit 5b87686e32 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Commit 0b91b53323 ("tty: n_gsm: Save dlci address open status when config requester")
Commit 46292622ad ("tty: n_gsm: clean up indenting in gsm_queue()")
However, the following behavior can be seen with this implementation:
- n_gsm ldisc is activated via ioctl
- all configuration parameters are set to their default value (initiator=0)
- the mux gets activated and attached and gsmtty0 is being registered in
in gsm_dlci_open() after DLCI 0 was established (DLCI 0 is the control
channel)
- the user configures n_gsm via ioctl GSMIOC_SETCONF as initiator
- this re-attaches the n_gsm mux
- no new gsmtty devices are registered in gsmld_attach_gsm() because the
mux is already active
- the initiator side registered only the control channel as gsmtty0
(which should never happen) and no user channel tty
The commits above make it impossible to operate the initiator side as no
user channel tty is or will be available.
On the other hand, this behavior will make it also impossible to allow DLCI
parameter negotiation on responder side in the future. The responder side
first needs to provide a device for the application before the application
can set its parameters of the associated DLCI via ioctl.
Note that the user application is still able to detect a link establishment
without relaying to uevent by waiting for DTR open on responder side. This
is the same behavior as on a physical serial interface. And on initiator
side a tty hangup can be detected if a link establishment request failed.
Revert the commits above completely to always register all user channels
and no control channel after mux attachment. No other changes are made.
Fixes: 5b87686e32 ("tty: n_gsm: Modify gsmtty driver register method when config requester")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220422071025.5490-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.2.1.2 describes the encoding of the
address field within the frame header. It is made up of the DLCI address,
command/response (CR) bit and EA bit.
Use the predefined CR value instead of a plain 2 in alignment to the
remaining code and to make the encoding obvious.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove commented out code as it is never used and if anyone accidentally
turned it on, it would be broken.
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the peer is not informed about the initial state of the modem
control lines after a new DLCI has been opened.
Fix this by sending the initial modem control line states after DLCI open.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220420101346.3315-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.4.4.2 states that any received unnumbered
acknowledgment (UA) with its poll/final (PF) bit set to 0 shall be
discarded. Currently, all UA frame are handled in the same way regardless
of the PF bit. This does not comply with the standard.
Remove the UA case in gsm_queue() to process only UA frames with PF bit set
to 1 to abide the standard.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-20-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gsmtty_write() and gsm_dlci_data_output() properly guard the fifo access.
However, gsm_dlci_close() and gsmtty_flush_buffer() modifies the fifo but
do not guard this.
Add a guard here to prevent race conditions on parallel writes to the fifo.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-17-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gsm_control_modem() informs the virtual tty that more data can be written
after receiving a control signal octet via modem status command (MSC).
However, gsm_dlci_data() fails to do the same after receiving a control
signal octet from the convergence layer type 2 header.
Add tty_wakeup() in gsm_dlci_data() for convergence layer type 2 to fix
this.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-14-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. The value of the modem status command (MSC) frame
contains an address field, control signal and optional break signal octet.
The address field is encoded as described in chapter 5.2.1.2 with only one
octet (may be extended to more in future versions of the standard). Whereas
the control signal and break signal octet are always one byte each. This is
strange at first glance as it makes the EA bit redundant. However, the same
two octets are also encoded as header in convergence layer type 2 as
described in chapter 5.5.2. No header length field is given and the only
way to test if there is an optional break signal octet is via the EA flag
which extends the control signal octet with a break signal octet. Now it
becomes obvious how the EA bit for those two octets shall be encoded in the
MSC frame. The current implementation treats the signal octet different for
MSC frame and convergence layer type 2 header even though the standard
describes it for both in the same way.
Use the EA bit to encode the signal octets not only in the convergence
layer type 2 header but also in the MSC frame in the same way with either
1 or 2 bytes in case of an optional break signal. Adjust the receiving path
accordingly in gsm_control_modem().
Fixes: 3ac06b9056 ("tty: n_gsm: Fix for modems with brk in modem status control")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-13-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.4.6.1 states that each command frame shall
be made up from type, length and value. Looking for example in chapter
5.4.6.3.5 at the description for the encoding of a flow control on command
it becomes obvious, that the type and length field is always present
whereas the value may be zero bytes long. The current implementation omits
the length field if the value is not present. This is wrong.
Correct this by always sending the length in gsm_control_transmit().
So far only the modem status command (MSC) has included a value and encoded
its length directly. Therefore, also change gsmtty_modem_update().
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-12-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.7.3 states that the valid range for the
maximum number of retransmissions (N2) is from 0 to 255 (both including).
gsm_config() fails to limit this range correctly. Furthermore,
gsm_control_retransmit() handles this number incorrectly by performing
N2 - 1 retransmission attempts. Setting N2 to zero results in more than 255
retransmission attempts.
Fix the range check in gsm_config() and the value handling in
gsm_control_send() and gsm_control_retransmit() to comply with 3GPP 27.010.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-11-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In gsm_cleanup_mux() the muxer is closed down and all queues are removed.
However, removing the queues is done without explicit control of the
underlying buffers. Flush those before freeing up our queues to ensure
that all outgoing queues are cleared consistently. Otherwise, a new mux
connection establishment attempt may time out while the underlying tty is
still busy sending out the remaining data from the previous connection.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-10-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current DLCI release order starts with the control channel followed by
the user channels. Reverse this order to keep the control channel open
until all user channels have been released.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-9-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.7.2 states that the maximum frame size
(N1) refers to the length of the information field (i.e. user payload).
However, 'txframe' stores the whole frame including frame header, checksum
and start/end flags. We also need to consider the byte stuffing overhead.
Define constant for the protocol overhead and adjust the 'txframe' size
calculation accordingly to reserve enough space for a complete mux frame
including byte stuffing for advanced option mode. Note that no byte
stuffing is applied to the start and end flag.
Also use MAX_MTU instead of MAX_MRU as this buffer is used for data
transmission.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-8-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The gsm_mux field 'malformed' represents the number of malformed frames
received. However, gsm1_receive() also increases this counter for any out
of frame byte.
Fix this by ignoring out of frame data for the malformed counter.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-7-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The frame checksum (FCS) is currently handled in gsm_queue() after
reception of a frame. However, this breaks layering. A workaround with
'received_fcs' was implemented so far.
Furthermore, frames are handled as such even if no end flag was received.
Move FCS calculation from gsm_queue() to gsm0_receive() and gsm1_receive().
Also delay gsm_queue() call there until a full frame was received to fix
both points.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-6-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.5.2 describes that the signal octet in
convergence layer type 2 can be either one or two bytes. The length is
encoded in the EA bit. This is set 1 for the last byte in the sequence.
gsmtty_modem_update() handles this correctly but gsm_dlci_data_output()
fails to set EA to 1. There is no case in which we encode two signal octets
as there is no case in which we send out a break signal.
Therefore, always set the EA bit to 1 for the signal octet to fix this.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-5-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Internally, we manage the alive state of the mux channels and mux itself
with the field member 'dead'. This makes it possible to notify the user
if the accessed underlying link is already gone. On the other hand,
however, removing the virtual ttys before terminating the channels may
result in peer messages being received without any internal target. Move
the mux cleanup procedure from gsmld_detach_gsm() to gsmld_close() to fix
this by keeping the virtual ttys open until the mux has been cleaned up.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-4-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The active mux instances are managed in the gsm_mux array and via mux_get()
and mux_put() functions separately. This gives a very loose coupling
between the actual instance and the gsm_mux array which manages it. It also
results in unnecessary lockings which makes it prone to failures. And it
creates a race condition if more than the maximum number of mux instances
are requested while the user changes the parameters of an active instance.
The user may loose ownership of the current mux instance in this case.
Fix this by moving the gsm_mux array handling to the mux allocation and
deallocation functions.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.8.2 states that both sides will revert to
the non-multiplexed mode via a close-down message (CLD). The usual program
flow is as following:
- start multiplex mode by sending AT+CMUX to the mobile
- establish the control channel (DLCI 0)
- establish user channels (DLCI >0)
- terminate user channels
- send close-down message (CLD)
- revert to AT protocol (i.e. leave multiplexed mode)
The AT protocol is out of scope of the n_gsm driver. However,
gsm_disconnect() sends CLD if gsm_config() detects that the requested
parameters require the mux protocol to restart. The next immediate action
is to start the mux protocol by opening DLCI 0 again. Any responder side
which handles CLD commands correctly forces us to fail at this point
because AT+CMUX needs to be sent to the mobile to start the mux again.
Therefore, remove the CLD command in this phase and keep both sides in
multiplexed mode.
Remove the gsm_disconnect() function as it become unnecessary and merge the
remaining parts into gsm_cleanup_mux() to handle the termination order and
locking correctly.
Fixes: 71e0779153 ("tty: n_gsm: do not send/receive in ldisc close path")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, only the initiator resets the mux protocol if the user requests
new parameters that are incompatible to those of the current connection.
The responder also needs to reset the multiplexer if the new parameter set
requires this. Otherwise, we end up with an inconsistent parameter set
between initiator and responder.
Revert the old behavior to inform the peer upon an incompatible parameter
set change from the user on the responder side by re-establishing the mux
protocol in such case.
Fixes: 509067bbd2 ("tty: n_gsm: Delete gsm_disconnect when config requester")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the current implementation the user may open a virtual tty which then
could fail to establish the underlying DLCI. The function gsmtty_open()
gets stuck in tty_port_block_til_ready() while waiting for a carrier rise.
This happens if the remote side fails to acknowledge the link establishment
request in time or completely. At some point gsm_dlci_close() is called
to abort the link establishment attempt. The function tries to inform the
associated virtual tty by performing a hangup. But the blocking loop within
tty_port_block_til_ready() is not informed about this event.
The patch proposed here fixes this by resetting the initialization state of
the virtual tty to ensure the loop exits and triggering it to make
tty_port_block_til_ready() return.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220218073123.2121-7-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function gsm_process_modem() exists to handle modem status bits of
incoming frames. This includes incoming MSC (modem status command) frames
and convergence layer type 2 data frames. The function, however, was only
designed to handle MSC frames as it expects the command length. Within
gsm_dlci_data() it is wrongly assumed that this is the same as the data
frame length. This is only true if the data frame contains only 1 byte of
payload.
This patch names the length parameter of gsm_process_modem() in a generic
manner to reflect its association. It also corrects all calls to the
function to handle the variable number of modem status octets correctly in
both cases.
Fixes: 7263287af9 ("tty: n_gsm: Fixed logic to decode break signal from modem status")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220218073123.2121-6-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty flow control is handled via gsmtty_throttle() and gsmtty_unthrottle().
Both functions propagate the outgoing hardware flow control state to the
remote side via MSC (modem status command) frames. The local state is taken
from the RTS (ready to send) flag of the tty. However, RTS gets mapped to
DTR (data terminal ready), which is wrong.
This patch corrects this by mapping RTS to RTS.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220218073123.2121-5-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The here fixed commit made the tty hangup asynchronous to avoid a circular
locking warning. I could not reproduce this warning. Furthermore, due to
the asynchronous hangup the function call now gets queued up while the
underlying tty is being freed. Depending on the timing this results in a
NULL pointer access in the global work queue scheduler. To be precise in
process_one_work(). Therefore, the previous commit made the issue worse
which it tried to fix.
This patch fixes this by falling back to the old behavior which uses a
blocking tty hangup call before freeing up the associated tty.
Fixes: 7030082a74 ("tty: n_gsm: avoid recursive locking with async port hangup")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220218073123.2121-4-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trying to open a DLCI by sending a SABM frame may fail with a timeout.
The link is closed on the initiator side without informing the responder
about this event. The responder assumes the link is open after sending a
UA frame to answer the SABM frame. The link gets stuck in a half open
state.
This patch fixes this by initiating the proper link termination procedure
after link setup timeout instead of silently closing it down.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220218073123.2121-3-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.2.1.2 describes the encoding of the
C/R (command/response) bit. Table 1 shows that the actual encoding of the
C/R bit is inverted if the associated frame is sent by the responder.
The referenced commit fixed here further broke the internal meaning of this
bit in the outgoing path by always setting the C/R bit regardless of the
frame type.
This patch fixes both by setting the C/R bit always consistently for
command (1) and response (0) frames and inverting it later for the
responder where necessary. The meaning of this bit in the debug output
is being preserved and shows the bit as if it was encoded by the initiator.
This reflects only the frame type rather than the encoded combination of
communication side and frame type.
Fixes: cc0f42122a ("tty: n_gsm: Modify CR,PF bit when config requester")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220218073123.2121-2-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.4.6.3.7 describes the encoding of the
control signal octet used by the MSC (modem status command). The same
encoding is also used in convergence layer type 2 as described in chapter
5.5.2. Table 7 and 24 both require the DV (data valid) bit to be set 1 for
outgoing control signal octets sent by the DTE (data terminal equipment),
i.e. for the initiator side.
Currently, the DV bit is only set if CD (carrier detect) is on, regardless
of the side.
This patch fixes this behavior by setting the DV bit on the initiator side
unconditionally.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220218073123.2121-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010.
See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to
the newer 27.010 here. Chapter 5.2.7.3 states that DC1 (XON) and DC3 (XOFF)
are the control characters defined in ISO/IEC 646. These shall be quoted if
seen in the data stream to avoid interpretation as flow control characters.
ISO/IEC 646 refers to the set of ISO standards described as the ISO
7-bit coded character set for information interchange. Its final version
is also known as ITU T.50.
See https://www.itu.int/rec/T-REC-T.50-199209-I/en
To abide the standard it is needed to quote DC1 and DC3 correctly if these
are seen as data bytes and not as control characters. The current
implementation already tries to enforce this but fails to catch all
defined cases. 3GPP 27.010 chapter 5.2.7.3 clearly states that the most
significant bit shall be ignored for DC1 and DC3 handling. The current
implementation handles only the case with the most significant bit set 0.
Cases in which DC1 and DC3 have the most significant bit set 1 are left
unhandled.
This patch fixes this by masking the data bytes with ISO_IEC_646_MASK (only
the 7 least significant bits set 1) before comparing them with XON
(a.k.a. DC1) and XOFF (a.k.a. DC3) when testing which byte values need
quotation via byte stuffing.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220120101857.2509-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After the previous patches, noone needs 'file' parameter in neither
ioctl hook from tty_ldisc_ops. So remove 'file' from both of them.
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> [NFC]
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211122094529.24171-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We currently have gsmld_output() ignore the return value from device
write. This means we will lose packets if device write returns 0 or
an error.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20210930060624.46523-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These two lines need to be indented one more tab.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20211004104343.GF25015@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After the previous patch, there are no users of 'file' in
n_tty_ioctl_helper. So remove it also from there.
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210914091134.17426-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As requester,because n_gsm has no uevent report for application,the
application can't know dlci connect or disconnect.
The application will control every dlcl dev by uevent,when application
receive gsmtty0 dev remove uevent,it will close mux function,and change to
normal mode.
Example:
Before modify:
gsmld receive DLC0 DISC,no event report to application
gsmld receive DLC1 SABM,no event report to application
gsmld receive DLC1 DISC,no event report to application
After modify:
Receive DLC0 DISC,report "/devices/virtual/tty/gsmtty0" remove uevent
Receive DLC1 SABM,report "/devices/virtual/tty/gsmtty1" add uevent
Receive DLC1 DISC,report "/devices/virtual/tty/gsmtty1" remove uevent
Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com>
Link: https://lore.kernel.org/r/1629461872-26965-7-git-send-email-zhenguo6858@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When n_gsm config "initiator=0",when gsmld config ,as requester ,it
doesn't need to send CLD frame data or SABM frame.
Example,when tty dev receive "AT+CMUX=0",it will change ldisc
n_tty to n_gsm,during config requester,gsmld output "7e 01 ef c3 aa 7e",
initiator maybe not want to receive the frame data.
[ 154.666457] c1 Q> 0) R: UIH(F)
[ 154.669514] c1 C3
[ 154.671519] c1 gsmld_output: 00000000: 7e 01 ef c3 aa 7e
[ 155.014874] c1 Q> 0) R: UIH(F)
[ 155.018000] c1 C3
[ 155.020046] c1 gsmld_output: 00000000: 7e 01 ef c3 aa 7e
[ 155.364425] c1 Q> 0) R: UIH(F)
[ 155.367546] c1 C3
[ 155.369597] c1 gsmld_output: 00000000: 7e 01 ef c3 aa 7e
Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com>
Link: https://lore.kernel.org/r/1629461872-26965-5-git-send-email-zhenguo6858@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
put_tty_driver() is an alias for tty_driver_kref_put(). There is no need
for two exported identical functions, therefore switch all users of
old put_tty_driver() to new tty_driver_kref_put() and remove the former
for good.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Acked-by: Alex Elder <elder@linaro.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
alloc_tty_driver was deprecated by tty_alloc_driver in commit
7f0bc6a68e (TTY: pass flags to alloc_tty_driver) in 2012.
I never got into eliminating alloc_tty_driver until now. So we still
have two functions for allocating drivers which might be confusing. So
get rid of alloc_tty_driver uses to eliminate it for good in the next
patch.
Note we need to switch return value checking as tty_alloc_driver uses
ERR_PTR. And flags are now a parameter of tty_alloc_driver.
Cc: Richard Henderson <rth@twiddle.net>(odd fixer:ALPHA PORT)
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes the following W=1 kernel build warning(s):
drivers/tty/n_gsm.c:525: warning: expecting prototype for gsm_stuff_packet(). Prototype was for gsm_stuff_frame() instead
drivers/tty/n_gsm.c:1608: warning: expecting prototype for gsm_dlci_control(). Prototype was for gsm_dlci_command() instead
drivers/tty/n_gsm.c:2561: warning: Function parameter or member 'cookie' not described in 'gsmld_read'
drivers/tty/n_gsm.c:2561: warning: Function parameter or member 'offset' not described in 'gsmld_read'
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210520121906.3468725-11-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_operations::chars_in_buffer is another hook which is expected to
return values >= 0. So make it explicit by the return type too -- use
unsigned int.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-27-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Line disciplines expect a positive value or zero returned from
tty->ops->write_room (invoked by tty_write_room). So make this
assumption explicit by using unsigned int as a return value. Both of
tty->ops->write_room and tty_write_room.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Alex Elder <elder@linaro.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa
Acked-by: David Sterba <dsterba@suse.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Chris Zankel <chris@zankel.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_unregister_ldisc now returns 0 = success. No need to check the
return value. In fact, the users only warned if an error occured and
didn't do anything useful anyway -- the ldisc module was unloaded in any
case.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210505091928.22010-19-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make tty_unregister_ldisc symmetric to tty_register_ldisc by accepting
struct tty_ldisc_ops as a parameter instead of ldisc number. This avoids
checking of the ldisc number bounds in tty_unregister_ldisc.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210505091928.22010-17-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the classic failpath handling using gotos in gsm_init. That way,
tty_unregister_ldisc needs not be repeated on two places.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-16-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no reason to pass the ldisc number to tty_register_ldisc
separately. Just set it in the already defined tty_ldisc_ops in all the
ldiscs.
This simplifies tty_register_ldisc a bit too (no need to set the num
member there).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210505091928.22010-15-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Char pointer (cp) passed to tty_ldisc_ops::receive_buf{,2} is const.
There is no reason for flag pointer (fp) not to be too. So switch it in
the definition and all uses.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-12-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a lot of tty-core-only functions that are listed in
include/linux/tty.h. Move them to drivers/tty/tty.h so that no one else
can accidentally call them or think that they are public functions.
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
spinlock can be initialized automatically with DEFINE_SPINLOCK()
rather than explicitly calling spin_lock_init().
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Guobin Huang <huangguobin4@huawei.com>
Link: https://lore.kernel.org/r/1617710163-48158-1-git-send-email-huangguobin4@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty line disciplines don't expect tty_operations::write_room to
return negative values. Fix the five drivers which violate this.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-44-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty line disciplines don't expect tty_operations::chars_in_buffer to
return negative values. Fix the two drivers which violate this.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-43-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dp, f, and i are only duplicates of gsmld_receive_buf's parameters. Use
the parameters directly (cp, fp, and count) and delete these local
variables.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-41-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
First, it is never checked. Second, use of it as a debugging aid is
at least questionable. With the current tools, I don't think anyone used
this kind of thing for debugging purposes for years.
On the top of that, e.g. serdev does not set this field of tty_ldisc_ops
at all.
So get rid of this legacy.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes both the "splice/sendfile to a tty" and "splice/sendfile from a
tty" regression from 5.10.
* 'tty-splice' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux:
tty: teach the n_tty ICANON case about the new "cookie continuations" too
tty: teach n_tty line discipline about the new "cookie continuations"
tty: clean up legacy leftovers from n_tty line discipline
tty: implement read_iter
tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
tty: implement write_iter
The tty line discipline .read() function was passed the final user
pointer destination as an argument, which doesn't match the 'write()'
function, and makes it very inconvenient to do a splice method for
ttys.
This is a conversion to use a kernel buffer instead.
NOTE! It does this by passing the tty line discipline ->read() function
an additional "cookie" to fill in, and an offset into the cookie data.
The line discipline can fill in the cookie data with its own private
information, and then the reader will repeat the read until either the
cookie is cleared or it runs out of data.
The only real user of this is N_HDLC, which can use this to handle big
packets, even if the kernel buffer is smaller than the whole packet.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes the following W=1 kernel build warning(s):
drivers/tty/n_gsm.c:85: warning: Function parameter or member 'ref' not described in 'gsm_mux_net'
drivers/tty/n_gsm.c:85: warning: Function parameter or member 'dlci' not described in 'gsm_mux_net'
drivers/tty/n_gsm.c:664: warning: Function parameter or member 'dlci' not described in 'gsm_data_kick'
drivers/tty/n_gsm.c:1015: warning: Function parameter or member 'clen' not described in 'gsm_process_modem'
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104193549.4026187-19-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge 5.9-rc3 into tty-next
We need the tty/serial fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gsm->output and ->error are set only to gsmld_output and gsm_error,
respectively. Call these functions directly and remove error and output
function pointers from struct gsm_mux completely.
Note: we need a forward declaration of gsmld_output now.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200818085655.12071-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When submitting the previous fix "tty: n_gsm: Fix waking up upper tty
layer when room available". It was suggested to switch from a while to
a for loop, but when doing it, there was a remaining bogus i++.
This patch removes this i++ and also reorganizes the code making it more
compact.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20200518084517.2173242-3-gregory.clement@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the length is zero then the print_hex_dump_bytes won't output
anything, so testing the length before the call is unnecessary.
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20200518084517.2173242-2-gregory.clement@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Warn the upper layer when n_gms is ready to receive data
again. Without this the associated virtual tty remains blocked
indefinitely.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20200512115323.1447922-4-gregory.clement@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For at least some modems like the TELIT LE910, skipping SOF makes
transfers blocking indefinitely after a short amount of data
transferred.
Given the small improvement provided by skipping the SOF (just one
byte on about 100 bytes), it seems better to completely remove this
"feature" than make it optional.
Fixes: e1eaea46bb ("tty: n_gsm line discipline")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20200512115323.1447922-3-gregory.clement@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both gsm_dlci->constipated and gsm_mux->constipated are used as bools,
so treat them as such.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219084949.28074-9-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both gsm_dlci->dead and gsm_mux->dead are used as bools, so treat them
as such.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219084949.28074-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mazin Al Haddad