[ Upstream commit 8493eab026 ]
When uart_flush_buffer() is called, the .flush_buffer() callback zeroes
the tx_dma_len field. This may race with the work queue function
handling transmit DMA requests:
1. If the buffer is flushed before the first DMA API call,
dmaengine_prep_slave_single() may be called with a zero length,
causing the DMA request to never complete, leading to messages
like:
rcar-dmac e7300000.dma-controller: Channel Address Error happen
and, with debug enabled:
sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126
and DMA timeouts.
2. If the buffer is flushed after the first DMA API call, but before
the second, dma_sync_single_for_device() may be called with a zero
length, causing the transmit data not to be flushed to RAM, and
leading to stale data being output.
Fix this by:
1. Letting sci_dma_tx_work_fn() return immediately if the transmit
buffer is empty,
2. Extending the critical section to cover all DMA preparational work,
so tx_dma_len stays consistent for all of it,
3. Using local copies of circ_buf.head and circ_buf.tail, to make sure
they match the actual operation above.
Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Suggested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 13b18d3590 ]
A bug was introduced by commit b3b5764618 ("tty: serial_core: convert
uart_open to use tty_port_open"). It caused a constant warning printed
into the system log regarding the tty and port counter mismatch:
[ 21.644197] ttyS ttySx: tty_port_close_start: tty->count = 1 port count = 2
in case if session hangup was detected so the warning is printed starting
from the second open-close iteration.
Particularly the problem was discovered in situation when there is a
serial tty device without hardware back-end being setup. It is considered
by the tty-serial subsystems as a hardware problem with session hang up.
In this case uart_startup() will return a positive value with TTY_IO_ERROR
flag set in corresponding tty_struct instance. The same value will get
passed to be returned from the activate() callback and then being returned
from tty_port_open(). But since in this case tty_port_block_til_ready()
isn't called the TTY_PORT_ACTIVE flag isn't set (while the method had been
called before tty_port_open conversion was introduced and the rest of the
subsystem code expected the bit being set in this case), which prevents the
uart_hangup() method to perform any cleanups including the tty port
counter setting to zero. So the next attempt to open/close the tty device
will discover the counters mismatch.
In order to fix the problem we need to manually set the TTY_PORT_ACTIVE
flag in case if uart_startup() returned a positive value. In this case
the hang up procedure will perform a full set of cleanup actions including
the port ref-counter resetting.
Fixes: b3b5764618 "tty: serial_core: convert uart_open to use tty_port_open"
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit db1b5bc047 ]
Interrupt handler checked THRE bit (transmitter holding register
empty) in LSR to detect if TX fifo is empty.
In case when there is only receive interrupts the TX handling
got called because THRE bit in LSR is set when there is no
transmission (FIFO empty). TX handling caused TX stop, which in
RS-485 half-duplex mode actually resets receiver FIFO. This is not
desired during reception because of possible data loss.
The fix is to check if THRI is set in IER in addition of the TX
fifo status. THRI in IER is set when TX is started and cleared
when TX is stopped.
This ensures that TX handling is only called when there is really
transmission on going and an interrupt for THRE and not when there
are only RX interrupts.
Signed-off-by: Kimmo Rautkoski <ext-kimmo.rautkoski@vaisala.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ba3684f99f ]
The function msm_wait_for_xmitr can be taken with interrupts
disabled. In order to avoid a potential system lockup - demonstrated
under stress testing conditions on SoC QCS404/5 - make sure we wait
for a bounded amount of time.
Tested on SoC QCS404.
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 06aaa3d066 ]
SMC relocation can also be activated earlier by the bootloader,
so the driver's behaviour cannot rely on selected kernel config.
When the SMC is relocated, CPM_CR_INIT_TRX cannot be used.
But the only thing CPM_CR_INIT_TRX does is to clear the
rstate and tstate registers, so this can be done manually,
even when SMC is not relocated.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: 9ab9212014 ("cpm_uart: fix non-console port startup bug")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 35240ba26a ]
Current calculator doesn't do it' job quite correct. First of all the
max310x baud-rates generator supports the divisor being less than 16.
In this case the x2/x4 modes can be used to double or quadruple
the reference frequency. But the current baud-rate setter function
just filters all these modes out by the first condition and setups
these modes only if there is a clocks-baud division remainder. The former
doesn't seem right at all, since enabling the x2/x4 modes causes the line
noise tolerance reduction and should be only used as a last resort to
enable a requested too high baud-rate.
Finally the fraction is supposed to be calculated from D = Fref/(c*baud)
formulae, but not from D % 16, which causes the precision loss. So to speak
the current baud-rate calculator code works well only if the baud perfectly
fits to the uart reference input frequency.
Lets fix the calculator by implementing the algo fully compliant with
the fractional baud-rate generator described in the datasheet:
D = Fref / (c*baud), where c={16,8,4} is the x1/x2/x4 rate mode
respectively, Fref - reference input frequency. The divisor fraction is
calculated from the same formulae, but making sure it is found with a
resolution of 0.0625 (four bits).
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3f2640ed7b upstream.
This reverts commit 2e9fe53910.
Reading LSR unconditionally but processing the error flags only if
UART_IIR_RDI bit was set before in IIR may lead to a loss of transmission
error information on UARTs where the transmission error flags are cleared
by a read of LSR. Information are lost in case an error is detected right
before the read of LSR while processing e.g. an UART_IIR_THRI interrupt.
Signed-off-by: Oliver Barta <o.barta89@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: 2e9fe53910 ("serial: 8250: Don't service RX FIFO if interrupts are disabled")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 07a6d63eb1 ]
In d5a2aa24, the name in struct console sunhv_console was changed from "ttyS"
to "ttyHV" while the name in struct uart_ops sunhv_pops remained unchanged.
This results in the hypervisor console device to be listed as "ttyHV0" under
/proc/consoles while the device node is still named "ttyS0":
root@osaka:~# cat /proc/consoles
ttyHV0 -W- (EC p ) 4:64
tty0 -WU (E ) 4:1
root@osaka:~# readlink /sys/dev/char/4:64
../../devices/root/f02836f0/f0285690/tty/ttyS0
root@osaka:~#
This means that any userland code which tries to determine the name of the
device file of the hypervisor console device can not rely on the information
provided by /proc/consoles. In particular, booting current versions of debian-
installer inside a SPARC LDOM will fail with the installer unable to determine
the console device.
After renaming the device in struct uart_ops sunhv_pops to "ttyHV" as well,
the inconsistency is fixed and it is possible again to determine the name
of the device file of the hypervisor console device by reading the contents
of /proc/console:
root@osaka:~# cat /proc/consoles
ttyHV0 -W- (EC p ) 4:64
tty0 -WU (E ) 4:1
root@osaka:~# readlink /sys/dev/char/4:64
../../devices/root/f02836f0/f0285690/tty/ttyHV0
root@osaka:~#
With this change, debian-installer works correctly when installing inside
a SPARC LDOM.
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5ba846b1ee ]
Intel IOMMU, when enabled, tries to find the domain of the device,
assuming it's a PCI one, during DMA operations, such as mapping or
unmapping. Since we are splitting the actual PCI device to couple of
children via MFD framework (see drivers/mfd/intel-lpss.c for details),
the DMA device appears to be a platform one, and thus not an actual one
that performs DMA. In a such situation IOMMU can't find or allocate
a proper domain for its operations. As a result, all DMA operations are
failed.
In order to fix this, supply parent of the platform device
to the DMA engine framework and fix filter functions accordingly.
We may rely on the fact that parent is a real PCI device, because no
other configuration is present in the wild.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [for tty parts]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4cdd17ba1d upstream.
We need to compute the uart state only on the first open. This is
usually what is done in the ->install hook. serial_core used to do this
in ->open on every open. So move it to ->install.
As a side effect, it ensures the state is set properly in the window
after tty_init_dev is called, but before uart_open. This fixes a bunch
of races between tty_open and flush_to_ldisc we were dealing with
recently.
One of such bugs was attempted to fix in commit fedb576064 (serial:
fix race between flush_to_ldisc and tty_open), but it only took care of
a couple of functions (uart_start and uart_unthrottle). I was able to
reproduce the crash on a SLE system, but in uart_write_room which is
also called from flush_to_ldisc via process_echoes. I was *unable* to
reproduce the bug locally. It is due to having this patch in my queue
since 2012!
general protection fault: 0000 [#1] SMP KASAN PTI
CPU: 1 PID: 5 Comm: kworker/u4:0 Tainted: G L 4.12.14-396-default #1 SLE15-SP1 (unreleased)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014
Workqueue: events_unbound flush_to_ldisc
task: ffff8800427d8040 task.stack: ffff8800427f0000
RIP: 0010:uart_write_room+0xc4/0x590
RSP: 0018:ffff8800427f7088 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000002f RSI: 00000000000000ee RDI: ffff88003888bd90
RBP: ffffffffb9545850 R08: 0000000000000001 R09: 0000000000000400
R10: ffff8800427d825c R11: 000000000000006e R12: 1ffff100084fee12
R13: ffffc900004c5000 R14: ffff88003888bb28 R15: 0000000000000178
FS: 0000000000000000(0000) GS:ffff880043300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561da0794148 CR3: 000000000ebf4000 CR4: 00000000000006e0
Call Trace:
tty_write_room+0x6d/0xc0
__process_echoes+0x55/0x870
n_tty_receive_buf_common+0x105e/0x26d0
tty_ldisc_receive_buf+0xb7/0x1c0
tty_port_default_receive_buf+0x107/0x180
flush_to_ldisc+0x35d/0x5c0
...
0 in rbx means tty->driver_data is NULL in uart_write_room. 0x178 is
tried to be dereferenced (0x178 >> 3 is 0x2f in rdx) at
uart_write_room+0xc4. 0x178 is exactly (struct uart_state *)NULL->refcount
used in uart_port_lock from uart_write_room.
So revert the upstream commit here as my local patch should fix the
whole family.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Wang Li <wangli39@baidu.com>
Cc: Zhang Yu <zhangyu31@baidu.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5d24f455c1 upstream.
The datasheet states:
Bit 4: ClockEnSet the ClockEn bit high to enable an external clocking
(crystal or clock generator at XIN). Set the ClockEn bit to 0 to disable
clocking
Bit 1: CrystalEnSet the CrystalEn bit high to enable the crystal
oscillator. When using an external clock source at XIN, CrystalEn must
be set low.
The bit 4, MAX310X_CLKSRC_EXTCLK_BIT, should be set and was not.
This was required to make the MAX3107 with an external crystal on our
board able to send or receive data.
Signed-off-by: Joe Burmeister <joe.burmeister@devtank.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 61c0e37950 upstream.
When the tty layer requests the uart to throttle, the current code
executing in msm_serial will trigger "Bad mode in Error Handler" and
generate an invalid stack frame in pstore before rebooting (that is if
pstore is indeed configured: otherwise the user shall just notice a
reboot with no further information dumped to the console).
This patch replaces the PIO byte accessor with the word accessor
already used in PIO mode.
Fixes: 68252424a7 ("tty: serial: msm: Support big-endian CPUs")
Cc: stable@vger.kernel.org
Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 72ff51d8dd ]
Andrey has reported on OpenWrt's bug tracking system[1], that he
currently can't use ar93xx_uart as pure serial UART without console
(CONFIG_SERIAL_8250_CONSOLE and CONFIG_SERIAL_AR933X_CONSOLE undefined),
because compilation ends with following error:
ar933x_uart.c: In function 'ar933x_uart_console_write':
ar933x_uart.c:550:14: error: 'struct uart_port' has no
member named 'sysrq'
So this patch moves all the code related to console handling behind
series of CONFIG_SERIAL_AR933X_CONSOLE ifdefs.
1. https://bugs.openwrt.org/index.php?do=details&task_id=2152
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Andrey Batyiev <batyiev@gmail.com>
Reported-by: Andrey Batyiev <batyiev@gmail.com>
Tested-by: Andrey Batyiev <batyiev@gmail.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
[ Upstream commit ac0cdb3d99 ]
Add the missing uart_unregister_driver() and i2c_del_driver() before return
from sc16is7xx_init() in the error handling case.
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
[ Upstream commit 4bb1ce2350 ]
When console device is rebinded, console_setup() is called again.
But marking it as __init means that function will be clear after boot is
complete. If console device is binded again console_setup() is not found
and error "Unable to handle kernel paging request at virtual address"
is reported.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 69646d7a36 upstream.
In half-duplex operation, RX should be started after TX completes.
If DMA is used, there is a case when the DMA transfer completes but the
TX FIFO is not emptied, so the RX cannot be restarted just yet.
Use a boolean variable to store this state and rearm TX interrupt mask
to be signaled again that the transfer finished. In interrupt transmit
handler this variable is used to start RX. A warning message is generated
if RX is activated before TX fifo is cleared.
Fixes: b389f173aa ("tty/serial: atmel: RS485 half duplex w/DMA: enable
RX after TX is done")
Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3ec8002951 upstream.
Echo "" to /sys/module/kgdboc/parameters/kgdboc will fail with "No such
device” error.
This is caused by function "configure_kgdboc" who init err to ENODEV
when the config is empty (legal input) the code go out with ENODEV
returned.
Fixes: 2dd4531686 ("kgdboc: Fix restrict error")
Signed-off-by: Wentao Wang <witallwang@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 93bcefd4c6 upstream.
We disable transmission interrupt (clear SCSCR_TIE) after all data has been transmitted
(if uart_circ_empty(xmit)). While transmitting, if the data is still in the tty buffer,
re-enable the SCSCR_TIE bit, which was done at sci_start_tx().
This is unnecessary processing, wasting CPU operation if the data transmission length is large.
And further, transmit end, FIFO empty bits disabling have also been performed in the step above.
Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3a10e3dd52 upstream.
of_match_device can return a NULL pointer when matching device is not
found. This patch avoids a scenario causing NULL pointer derefernce.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4350782570 upstream.
On Spreadtrum's serial device, nearly all of interrupts would be cleared
by hardware except timeout interrupt. This patch removed the operation
of clearing all interrupt in irq handler, instead added an if statement
to check if the timeout interrupt is supposed to be cleared.
Wrongly clearing timeout interrupt would lead to uart data stay in rx
fifo, that means the driver cannot read them out anymore.
Signed-off-by: Lanqing Liu <lanqing.liu@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 78d3820b9b upstream.
The four port Pericom chips have the fourth port at the wrong address.
Make use of quirk to fix it.
Fixes: c8d192428f ("serial: 8250: added acces i/o products quad and octal serial cards")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jay Dolan <jay.dolan@accesio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b896b03bc7 upstream.
Have the correct number of ports created for ACCES serial cards. Two port
cards show up as four ports, and four port cards show up as eight.
Fixes: c8d192428f ("serial: 8250: added acces i/o products quad and octal serial cards")
Signed-off-by: Jay Dolan <jay.dolan@accesio.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5c31ef91c0 upstream.
Hi,
below patch to fix Fourth port offset of Percom PI7C9X7954 boards.
I had a problem using Fourth port on a pci express serial board based on Pericom
PI7C9X7954. Reading datasheet I notice a "special" offset assign to this port
when used in I/O mode.
Offset 0x0 -> UART 0
Offset 0x8 -> UART 1
Offset 0x10 -> UART 2
Offset 0x38 -> UART 3 <<---- This don't follow a logical sequence
This patch add a different init to last port, to have right offset.
I check also Pericom 7952 and 7958 but that devices follow logical sequence,
so they are ok.
Regards,
Angelo
Signed-off-by: Angelo Butti <buttiangelo@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f4817843e3 upstream.
There are two other drivers that bind to mrvl,mmp-uart and both of them
assume register shift of 2 bits. There are device trees that lack the
property and rely on that assumption.
If this driver wins the race to bind to those devices, it should behave
the same as the older deprecated driver.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7abab16051 upstream.
If RX is disabled while there are still unprocessed bytes in RX FIFO,
cdns_uart_handle_rx() called from interrupt handler will get stuck in
the receive loop as read bytes will not get removed from the RX FIFO
and CDNS_UART_SR_RXEMPTY bit will never get set.
Avoid the stuck handler by checking first if RX is disabled. port->lock
protects against race with RX-disabling functions.
This HW behavior was mentioned by Nathan Rossi in 43e98facc4a3 ("tty:
xuartps: Fix RX hang, and TX corruption in termios call") which fixed a
similar issue in cdns_uart_set_termios().
The behavior can also be easily verified by e.g. setting
CDNS_UART_CR_RX_DIS at the beginning of cdns_uart_handle_rx() - the
following loop will then get stuck.
Resetting the FIFO using RXRST would not set RXEMPTY either so simply
issuing a reset after RX-disable would not work.
I observe this frequently on a ZynqMP board during heavy RX load at 1M
baudrate when the reader process exits and thus RX gets disabled.
Fixes: 61ec901698 ("tty/serial: add support for Xilinx PS UART")
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fedb576064 upstream.
There still is a race window after the commit b027e2298b
("tty: fix data race between tty_init_dev and flush of buf"),
and we encountered this crash issue if receive_buf call comes
before tty initialization completes in tty_open and
tty->driver_data may be NULL.
CPU0 CPU1
---- ----
tty_open
tty_init_dev
tty_ldisc_unlock
schedule
flush_to_ldisc
receive_buf
tty_port_default_receive_buf
tty_ldisc_receive_buf
n_tty_receive_buf_common
__receive_buf
uart_flush_chars
uart_start
/*tty->driver_data is NULL*/
tty->ops->open
/*init tty->driver_data*/
it can be fixed by extending ldisc semaphore lock in tty_init_dev
to driver_data initialized completely after tty->ops->open(), but
this will lead to get lock on one function and unlock in some other
function, and hard to maintain, so fix this race only by checking
tty->driver_data when receiving, and return if tty->driver_data
is NULL, and n_tty_receive_buf_common maybe calls uart_unthrottle,
so add the same check.
Because the tty layer knows nothing about the driver associated with the
device, the tty layer can not do anything here, it is up to the tty
driver itself to check for this type of race. Fix up the serial driver
to correctly check to see if it is finished binding with the device when
being called, and if not, abort the tty calls.
[Description and problem report and testing from Li RongQing, I rewrote
the patch to be in the serial layer, not in the tty core - gregkh]
Reported-by: Li RongQing <lirongqing@baidu.com>
Tested-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Wang Li <wangli39@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 31e9336457 ]
Commit 391f93f2ec ("serial: core: Rework hw-assited flow control support")
has changed the way the autoCTS mode is handled.
According to that change, serial drivers which enable H/W autoCTS mode must
set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling
TX. This patch adds proper handling of UPSTAT_AUTOCTS flag.
Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
[mszyprow: rephrased commit message]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d72402145a ]
LKP has hit yet another circular locking dependency between uart
console drivers and debugobjects [1]:
CPU0 CPU1
rhltable_init()
__init_work()
debug_object_init
uart_shutdown() /* db->lock */
/* uart_port->lock */ debug_print_object()
free_page() printk()
call_console_drivers()
debug_check_no_obj_freed() /* uart_port->lock */
/* db->lock */
debug_print_object()
So there are two dependency chains:
uart_port->lock -> db->lock
And
db->lock -> uart_port->lock
This particular circular locking dependency can be addressed in several
ways:
a) One way would be to move debug_print_object() out of db->lock scope
and, thus, break the db->lock -> uart_port->lock chain.
b) Another one would be to free() transmit buffer page out of db->lock
in UART code; which is what this patch does.
It makes sense to apply a) and b) independently: there are too many things
going on behind free(), none of which depend on uart_port->lock.
The patch fixes transmit buffer page free() in uart_shutdown() and,
additionally, in uart_port_startup() (as was suggested by Dmitry Safonov).
[1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d430aff8cd ]
The function of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
su_get_type() doesn't do that. The match node are used as an identifier
to compare against the current node, so we can directly drop the refcount
after getting the node from the path as it is not used as pointer.
Fix this by use a single variable and drop the refcount right after
of_find_node_by_path().
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dac097c454 ]
of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
This place is not doing this, so fix it.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit dada6a43b0 upstream.
This patch is trying to fix KE issue due to
"BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198"
reported by Syzkaller scan."
[26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198
[26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364
[26364:syz-executor0][name:report&]
[26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0
[26364:syz-executor0]Call trace:
[26364:syz-executor0][<ffffff9008095cf8>] dump_bacIctrace+Ox0/0x470
[26364:syz-executor0][<ffffff9008096de0>] show_stack+0x20/0x30
[26364:syz-executor0][<ffffff90089cc9c8>] dump_stack+Oxd8/0x128
[26364:syz-executor0][<ffffff90084edb38>] print_address_description +0x80/0x4a8
[26364:syz-executor0][<ffffff90084ee270>] kasan_report+Ox178/0x390
[26364:syz-executor0][<ffffff90084ee4a0>] _asan_report_loadi_noabort+Ox18/0x20
[26364:syz-executor0][<ffffff9008b092ac>] param_set_kgdboc_var+Ox194/0x198
[26364:syz-executor0][<ffffff900813af64>] param_attr_store+Ox14c/0x270
[26364:syz-executor0][<ffffff90081394c8>] module_attr_store+0x60/0x90
[26364:syz-executor0][<ffffff90086690c0>] sysfs_kl_write+Ox100/0x158
[26364:syz-executor0][<ffffff9008666d84>] kernfs_fop_write+0x27c/0x3a8
[26364:syz-executor0][<ffffff9008508264>] do_loop_readv_writev+0x114/0x1b0
[26364:syz-executor0][<ffffff9008509ac8>] do_readv_writev+0x4f8/0x5e0
[26364:syz-executor0][<ffffff9008509ce4>] vfs_writev+0x7c/Oxb8
[26364:syz-executor0][<ffffff900850ba64>] SyS_writev+Oxcc/0x208
[26364:syz-executor0][<ffffff90080883f0>] elO_svc_naked +0x24/0x28
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]The buggy address belongs to the variable:
[26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]Memory state around the buggy address:
[26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
[26364:syz-executor0][name:report&] ^
[26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
[26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint
[26364:syz-executor0]------------[cut here]------------
After checking the source code, we've found there might be an out-of-bounds
access to "config[len - 1]" array when the variable "len" is zero.
Signed-off-by: Macpaul Lin <macpaul@gmail.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 100bc3e2be upstream.
serial8250_register_8250_port calls uart_config_port, which calls
config_port on the port before it tries to power on the port. So we need
the port to be on before calling serial8250_register_8250_port. Change
the code to always do a runtime resume in probe before registering port,
and always do a runtime suspend in remove.
This basically reverts the change in commit 68e5fc4a25 ("tty: serial:
8250_mtk: use pm_runtime callbacks for enabling"), but still use
pm_runtime callbacks.
Fixes: 68e5fc4a25 ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling")
Signed-off-by: Peter Shih <pihsun@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1cd25cbb2f upstream.
After 2dd4531686 ("kgdboc: Fix restrict error"), kgdboc_option_setup is
now only used when built in, resulting in a warning when compiled as a
module:
drivers/tty/serial/kgdboc.c:134:12: warning: 'kgdboc_option_setup' defined but not used [-Wunused-function]
static int kgdboc_option_setup(char *opt)
^~~~~~~~~~~~~~~~~~~
Move the function under the appropriate ifdef for builtin only.
Fixes: 2dd4531686 ("kgdboc: Fix restrict error")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2dd4531686 upstream.
There's an error when compiled with restrict:
drivers/tty/serial/kgdboc.c: In function ‘configure_kgdboc’:
drivers/tty/serial/kgdboc.c:137:2: error: ‘strcpy’ source argument is the same
as destination [-Werror=restrict]
strcpy(config, opt);
^~~~~~~~~~~~~~~~~~~
As the error implies, this is from trying to use config as both source and
destination. Drop the call to the function where config is the argument
since nothing else happens in the function.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8344498721 ]
The SC16IS752 is a dual-channel device. The two channels are largely
independent, but the IRQ signals are wired together as an open-drain,
active low signal which will be driven low while either of the
channels requires attention, which can be for significant periods of
time until operations complete and the interrupt can be acknowledged.
In that respect it is should be treated as a true level-sensitive IRQ.
The kernel, however, needs to be able to exit interrupt context in
order to use I2C or SPI to access the device registers (which may
involve sleeping). Therefore the interrupt needs to be masked out or
paused in some way.
The usual way to manage sleeping from within an interrupt handler
is to use a threaded interrupt handler - a regular interrupt routine
does the minimum amount of work needed to triage the interrupt before
waking the interrupt service thread. If the threaded IRQ is marked as
IRQF_ONESHOT the kernel will automatically mask out the interrupt
until the thread runs to completion. The sc16is7xx driver used to
use a threaded IRQ, but a patch switched to using a kthread_worker
in order to set realtime priorities on the handler thread and for
other optimisations. The end result is non-threaded IRQ that
schedules some work then returns IRQ_HANDLED, making the kernel
think that all IRQ processing has completed.
The work-around to prevent a constant stream of interrupts is to
mark the interrupt as edge-sensitive rather than level-sensitive,
but interpreting an active-low source as a falling-edge source
requires care to prevent a total cessation of interrupts. Whereas
an edge-triggering source will generate a new edge for every interrupt
condition a level-triggering source will keep the signal at the
interrupting level until it no longer requires attention; in other
words, the host won't see another edge until all interrupt conditions
are cleared. It is therefore vital that the interrupt handler does not
exit with an outstanding interrupt condition, otherwise the kernel
will not receive another interrupt unless some other operation causes
the interrupt state on the device to be cleared.
The existing sc16is7xx driver has a very simple interrupt "thread"
(kthread_work job) that processes interrupts on each channel in turn
until there are no more. If both channels are active and the first
channel starts interrupting while the handler for the second channel
is running then it will not be detected and an IRQ stall ensues. This
could be handled easily if there was a shared IRQ status register, or
a convenient way to determine if the IRQ had been deasserted for any
length of time, but both appear to be lacking.
Avoid this problem (or at least make it much less likely to happen)
by reducing the granularity of per-channel interrupt processing
to one condition per iteration, only exiting the overall loop when
both channels are no longer interrupting.
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1bd54d851f upstream.
kgdboc_option_setup does not check input argument before passing it
to strlen. The argument would be a NULL pointer if "ekgdboc", without
its value, is set in command line and thus cause the following panic.
PANIC: early exception 0xe3 IP 10:ffffffff8fbbb620 error 0 cr2 0x0
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18-rc8+ #1
[ 0.000000] RIP: 0010:strlen+0x0/0x20
...
[ 0.000000] Call Trace
[ 0.000000] ? kgdboc_option_setup+0x9/0xa0
[ 0.000000] ? kgdboc_early_init+0x6/0x1b
[ 0.000000] ? do_early_param+0x4d/0x82
[ 0.000000] ? parse_args+0x212/0x330
[ 0.000000] ? rdinit_setup+0x26/0x26
[ 0.000000] ? parse_early_options+0x20/0x23
[ 0.000000] ? rdinit_setup+0x26/0x26
[ 0.000000] ? parse_early_param+0x2d/0x39
[ 0.000000] ? setup_arch+0x2f7/0xbf4
[ 0.000000] ? start_kernel+0x5e/0x4c2
[ 0.000000] ? load_ucode_bsp+0x113/0x12f
[ 0.000000] ? secondary_startup_64+0xa5/0xb0
This patch adds a check to prevent the panic.
Cc: stable@vger.kernel.org
Cc: jason.wessel@windriver.com
Cc: gregkh@linuxfoundation.org
Cc: jslaby@suse.com
Signed-off-by: He Zhe <zhe.he@windriver.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e0bf2d4982 upstream.
Apparently, this driver (or the hardware) does not support character
length settings. It's apparently running in 8-bit mode, but it makes
userspace believe it's in 5-bit mode. That makes tcsetattr with CS8
incorrectly fail, breaking e.g. getty from busybox, thus the login shell
on ttyMVx.
Fix by hard-wiring CS8 into c_cflag.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Fixes: 30530791a7 ("serial: mvebu-uart: initial support for Armada-3700 serial port")
Cc: stable <stable@vger.kernel.org> # 4.6+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3216c622a2 upstream.
The function tty_port_tty_get() gets a reference to the tty. Since
the code is not using tty_port_tty_set(), the reference is kept
even after closing the tty.
Avoid using tty_port_tty_get() by directly access the tty instance.
Since lpuart_start_rx_dma() is called from the .startup() and
.set_termios() callback, it is safe to assume the tty instance is
valid.
Cc: stable@vger.kernel.org # v4.9+
Fixes: 5887ad43ee ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
