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commit 28b0f8a6962a24ed21737578f3b1b07424635c9e upstream.
A tty is hung up by __tty_hangup() setting file->f_op to
hung_up_tty_fops, which is skipped on ttys whose write operation isn't
tty_write(). This means that, for example, /dev/console whose write
op is redirected_tty_write() is never actually marked hung up.
Because n_tty_read() uses the hung up status to decide whether to
abort the waiting readers, the lack of hung-up marking can lead to the
following scenario.
1. A session contains two processes. The leader and its child. The
child ignores SIGHUP.
2. The leader exits and starts disassociating from the controlling
terminal (/dev/console).
3. __tty_hangup() skips setting f_op to hung_up_tty_fops.
4. SIGHUP is delivered and ignored.
5. tty_ldisc_hangup() is invoked. It wakes up the waits which should
clear the read lockers of tty->ldisc_sem.
6. The reader wakes up but because tty_hung_up_p() is false, it
doesn't abort and goes back to sleep while read-holding
tty->ldisc_sem.
7. The leader progresses to tty_ldisc_lock() in tty_ldisc_hangup()
and is now stuck in D sleep indefinitely waiting for
tty->ldisc_sem.
The following is Alan's explanation on why some ttys aren't hung up.
http://lkml.kernel.org/r/20171101170908.6ad08580@alans-desktop
1. It broke the serial consoles because they would hang up and close
down the hardware. With tty_port that *should* be fixable properly
for any cases remaining.
2. The console layer was (and still is) completely broken and doens't
refcount properly. So if you turn on console hangups it breaks (as
indeed does freeing consoles and half a dozen other things).
As neither can be fixed quickly, this patch works around the problem
by introducing a new flag, TTY_HUPPING, which is used solely to tell
n_tty_read() that hang-up is in progress for the console and the
readers should be aborted regardless of the hung-up status of the
device.
The following is a sample hung task warning caused by this issue.
INFO: task agetty:2662 blocked for more than 120 seconds.
Not tainted 4.11.3-dbg-tty-lockup-02478-gfd6c7ee-dirty #28
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
0 2662 1 0x00000086
Call Trace:
__schedule+0x267/0x890
schedule+0x36/0x80
schedule_timeout+0x23c/0x2e0
ldsem_down_write+0xce/0x1f6
tty_ldisc_lock+0x16/0x30
tty_ldisc_hangup+0xb3/0x1b0
__tty_hangup+0x300/0x410
disassociate_ctty+0x6c/0x290
do_exit+0x7ef/0xb00
do_group_exit+0x3f/0xa0
get_signal+0x1b3/0x5d0
do_signal+0x28/0x660
exit_to_usermode_loop+0x46/0x86
do_syscall_64+0x9c/0xb0
entry_SYSCALL64_slow_path+0x25/0x25
The following is the repro. Run "$PROG /dev/console". The parent
process hangs in D state.
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include <time.h>
#include <termios.h>
int main(int argc, char **argv)
{
struct sigaction sact = { .sa_handler = SIG_IGN };
struct timespec ts1s = { .tv_sec = 1 };
pid_t pid;
int fd;
if (argc < 2) {
fprintf(stderr, "test-hung-tty /dev/$TTY\n");
return 1;
}
/* fork a child to ensure that it isn't already the session leader */
pid = fork();
if (pid < 0) {
perror("fork");
return 1;
}
if (pid > 0) {
/* top parent, wait for everyone */
while (waitpid(-1, NULL, 0) >= 0)
;
if (errno != ECHILD)
perror("waitpid");
return 0;
}
/* new session, start a new session and set the controlling tty */
if (setsid() < 0) {
perror("setsid");
return 1;
}
fd = open(argv[1], O_RDWR);
if (fd < 0) {
perror("open");
return 1;
}
if (ioctl(fd, TIOCSCTTY, 1) < 0) {
perror("ioctl");
return 1;
}
/* fork a child, sleep a bit and exit */
pid = fork();
if (pid < 0) {
perror("fork");
return 1;
}
if (pid > 0) {
nanosleep(&ts1s, NULL);
printf("Session leader exiting\n");
exit(0);
}
/*
* The child ignores SIGHUP and keeps reading from the controlling
* tty. Because SIGHUP is ignored, the child doesn't get killed on
* parent exit and the bug in n_tty makes the read(2) block the
* parent's control terminal hangup attempt. The parent ends up in
* D sleep until the child is explicitly killed.
*/
sigaction(SIGHUP, &sact, NULL);
printf("Child reading tty\n");
while (1) {
char buf[1024];
if (read(fd, buf, sizeof(buf)) < 0) {
perror("read");
return 1;
}
}
return 0;
}
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@llwyncelyn.cymru>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit ea3d8465ab9b3e01be329ac5195970a84bef76c5 ]
Some devices have the control dlci stay in ADM mode instead of the UA
mode. This can seen at least on droid 4 when trying to open the ts
27.010 mux port. Enabling n_gsm debug mode shows the control dlci
always respond with DM to SABM instead of UA:
# modprobe n_gsm debug=0xff
# ldattach -d GSM0710 /dev/ttyS0 &
gsmld_output: 00000000: f9 03 3f 01 1c f9
--> 0) C: SABM(P)
gsmld_receive: 00000000: f9 03 1f 01 36 f9
<-- 0) C: DM(P)
...
$ minicom -D /dev/gsmtty1
minicom: cannot open /dev/gsmtty1: No error information
$ strace minicom -D /dev/gsmtty1
...
open("/dev/gsmtty1", O_RDWR|O_NOCTTY|O_NONBLOCK|O_LARGEFILE) = -1 EL2HLT
Note that this is different issue from other n_gsm -EL2HLT issues such
as timeouts when the control dlci does not respond at all.
The ADM mode seems to be a quite common according to "RF Wireless World"
article "GSM Issue-UE sends SABM and gets a DM response instead of
UA response":
This issue is most commonly observed in GSM networks where in UE sends
SABM and expects network to send UA response but it ends up receiving
DM response from the network. SABM stands for Set asynchronous balanced
mode, UA stands for Unnumbered Acknowledge and DA stands for
Disconnected Mode.
An RLP entity can be in one of two modes:
- Asynchronous Balanced Mode (ABM)
- Asynchronous Disconnected Mode (ADM)
Currently Linux kernel closes the control dlci after several retries
in gsm_dlci_t1() on DM. This causes n_gsm /dev/gsmtty ports to produce
error code -EL2HLT when trying to open them as the closing of control
dlci has already set gsm->dead.
Let's fix the issue by allowing control dlci stay in ADM mode after the
retries so the /dev/gsmtty ports can be opened and used. It seems that
it might take several attempts to get any response from the control
dlci, so it's best to allow ADM mode only after the SABM retries are
done.
Note that for droid 4 additional patches are needed to mux the ttyS0
pins and to toggle RTS gpio_149 to wake up the mdm6600 modem are also
needed to use n_gsm. And the mdm6600 modem needs to be powered on.
Cc: linux-serial@vger.kernel.org
Cc: Alan Cox <alan@llwyncelyn.cymru>
Cc: Jiri Prchal <jiri.prchal@aksignal.cz>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Marcel Partap <mpartap@gmx.net>
Cc: Michael Scott <michael.scott@linaro.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Russ Gorby <russ.gorby@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e279e6d98e0cf2c2fe008b3c29042b92f0e17b1d ]
sccnxp driver doesn't get the correct uart clock rate, if CONFIG_HAVE_CLOCK
is disabled. Correct usage of clk API to make it work with/without it.
Fixes: 90efa75f7ab0 (serial: sccnxp: Using CLK API for getting UART clock)
Suggested-by: Russell King - ARM Linux <linux@armlinux.org.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 1cf4a7efdc71cab84c42cfea7200608711ea954f ]
If DMA is enabled and used, a burst of old data may be seen on the
serial console during "poweroff" or "reboot". uart_flush_buffer()
clears the circular buffer, but sci_port.tx_dma_len is not reset.
This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE -
sci_port.tx_dma_len) bytes.
To fix this, add a .flush_buffer() callback that resets
sci_port.tx_dma_len.
Inspired by commit 31ca2c63fdc0aee7 ("tty/serial: atmel: fix race
condition (TX+DMA)").
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 84b40e3b57eef1417479c00490dd4c9f6e5ffdbc ]
Kernel always writes log messages to console via
serial8250_console_write()->serial8250_console_putchar() which directly
accesses UART_TX register _without_ using DMA.
But, if other processes like systemd using same UART port, then these
writes are handled by a different code flow using 8250_omap driver where
there is provision to use DMA.
It seems that it is possible that both DMA and CPU might simultaneously
put data to UART FIFO and lead to potential loss of data due to FIFO
overflow and weird data corruption. This happens when both kernel
console and userspace tries to write simultaneously to the same UART
port. Therefore, disable DMA on kernel console port to avoid potential
race between CPU and DMA.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 65d9982d7e523a1a8e7c9af012da0d166f72fc56 upstream.
ECMA-48 [1] (aka ISO 6429) has defined SGR 21 as "doubly underlined"
since at least March 1984. The Linux kernel has treated it as SGR 22
"normal intensity" since it was added in Linux-0.96b in June 1992.
Before that, it was simply ignored. Other terminal emulators have
either ignored it, or treat it as double underline now. xterm for
example added support in its 304 release (May 2014) [2] where it was
previously ignoring it.
Changing this behavior shouldn't be an issue:
- It isn't a named capability in ncurses's terminfo database, so no
script is using libtinfo/libcurses to look this up, or using tput
to query & output the right sequence.
- Any script assuming SGR 21 will reset intensity in all terminals
already do not work correctly on non-Linux VTs (including running
under screen/tmux/etc...).
- If someone has written a script that only runs in the Linux VT, and
they're using SGR 21 (instead of SGR 22), the output should still
be readable.
imo it's important to change this as the Linux VT's non-conformance
is sometimes used as an argument for other terminal emulators to not
implement SGR 21 at all, or do so incorrectly.
[1]: https://www.ecma-international.org/publications/standards/Ecma-048.htm
[2]: https://github.com/ThomasDickey/xterm-snapshots/commit/2fd29cb98d214cb536bcafbee00bc73b3f1eeb9d
Signed-off-by: Mike Frysinger <vapier@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f1869a890cdedb92a3fab969db5d0fd982850273 upstream.
Tabs on a console with long lines do not wrap properly, so correctly
account for the line length when computing the tab placement location.
Reported-by: James Holderness <j4_james@hotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2b022ab7542df60021ab57854b3faaaf42552eaf ]
In case that CONFIG_SLUB_DEBUG is on and pty is used, races between
release_one_tty and flush_to_ldisc work threads may happen and lead
to use-after-free condition on tty->link->port. Because SLUB_DEBUG
is turned on, freed tty->link->port is filled with POISON_FREE value.
So far without SLUB_DEBUG, port was filled with zero and flush_to_ldisc
could return without a problem by checking if tty is NULL.
CPU 0 CPU 1
----- -----
release_tty pty_write
cancel_work_sync(tty) to = tty->link
tty_kref_put(tty->link) tty_schedule_flip(to->port)
<< workqueue >> ...
release_one_tty ...
pty_cleanup ...
kfree(tty->link->port) << workqueue >>
flush_to_ldisc
tty = READ_ONCE(port->itty)
tty is 0x6b6b6b6b6b6b6b6b
!!PANIC!! access tty->ldisc
Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b6b93
pgd = ffffffc0eb1c3000
[6b6b6b6b6b6b6b93] *pgd=0000000000000000, *pud=0000000000000000
------------[ cut here ]------------
Kernel BUG at ffffff800851154c [verbose debug info unavailable]
Internal error: Oops - BUG: 96000004 [#1] PREEMPT SMP
CPU: 3 PID: 265 Comm: kworker/u8:9 Tainted: G W 3.18.31-g0a58eeb #1
Hardware name: Qualcomm Technologies, Inc. MSM 8996pro v1.1 + PMI8996 Carbide (DT)
Workqueue: events_unbound flush_to_ldisc
task: ffffffc0ed610ec0 ti: ffffffc0ed624000 task.ti: ffffffc0ed624000
PC is at ldsem_down_read_trylock+0x0/0x4c
LR is at tty_ldisc_ref+0x24/0x4c
pc : [<ffffff800851154c>] lr : [<ffffff800850f6c0>] pstate: 80400145
sp : ffffffc0ed627cd0
x29: ffffffc0ed627cd0 x28: 0000000000000000
x27: ffffff8009e05000 x26: ffffffc0d382cfa0
x25: 0000000000000000 x24: ffffff800a012f08
x23: 0000000000000000 x22: ffffffc0703fbc88
x21: 6b6b6b6b6b6b6b6b x20: 6b6b6b6b6b6b6b93
x19: 0000000000000000 x18: 0000000000000001
x17: 00e80000f80d6f53 x16: 0000000000000001
x15: 0000007f7d826fff x14: 00000000000000a0
x13: 0000000000000000 x12: 0000000000000109
x11: 0000000000000000 x10: 0000000000000000
x9 : ffffffc0ed624000 x8 : ffffffc0ed611580
x7 : 0000000000000000 x6 : ffffff800a42e000
x5 : 00000000000003fc x4 : 0000000003bd1201
x3 : 0000000000000001 x2 : 0000000000000001
x1 : ffffff800851004c x0 : 6b6b6b6b6b6b6b93
Signed-off-by: Sahara <keun-o.park@darkmatter.ae>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 8af016aa5a27c6a2505460eb4d83f1e70c38dc43 ]
If there is no clock rate for uartclk defined, disable the previously
enabled clock again.
Found by Linux Driver Verification project (linuxtesting.org).
Fixes: 23f5b3fdd04e serial: 8250_dw: only get the clock rate in one place
Signed-off-by: Stefan Potyra <Stefan.Potyra@elektrobit.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e61c38d85b7392e033ee03bca46f1d6006156175 ]
If the UART is operated in DTE mode and UCR3_DCD or UCR3_RI are 1 (which
is the reset default) and the opposite side pulls the respective line to
its active level the irq triggers after it is requested in .probe.
These irqs were already disabled in .startup but this might be too late.
Also setup of the UFCR_DCEDTE bit (currently done in .set_termios) is
done very late which is critical as it also controls direction of some
pins.
So setup UFCR_DCEDTE earlier (in .probe) and also disable the broken
irqs in DTE mode there before requesting irqs.
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 7d05587c9e0e4611650bb403812e2d492c178a9f ]
On SMP systems, we see a lot of spurious TX interrupts when a
program generates a steady stream of output to the pl011 UART.
The problem can be easily seen when one CPU generates the output
while another CPU handles the pl011 interrupts, and the rate of
output is low enough not to fill the TX FIFO. The problem seems
to be:
-- CPU a -- -- CPU b --
(take port lock)
pl011_start_tx
pl011_start_tx_pio
enable TXIM in REG_IMSC -> causes uart tx intr (pl011_int)
pl011_tx_chars pl011_int
...tx chars, all done... (wait for port lock)
pl011_stop_tx .
disable TXIM .
(release port lock) -> (take port lock)
check for TXIM, not enabled
(release port lock)
return IRQ_NONE
Enabling the TXIM in pl011_start_tx_pio() causes the interrupt
to be generated and delivered to CPU b, even though pl011_tx_chars()
is able to complete the TX and then disable the tx interrupt.
Fix this by enabling TXIM only after pl011_tx_chars, if it is needed.
pl011_tx_chars will return a boolean indicating whether the TX
interrupts have to be enabled.
Debugged-by: Vijaya Kumar <Vijaya.Kumar@cavium.com>
Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1f66dd36bb18437397ea0d7882c52f7e3c476e15 upstream.
It will get the wrong virtual address because port->mapbase is not added
the correct reg-offset yet. We have to update it before earlycon_map()
is called
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: stable@vger.kernel.org
Fixes: 088da2a17619 ("of: earlycon: Initialize port fields from DT properties")
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 714569064adee3c114a2a6490735b94abe269068 upstream.
This is a followup on 44117a1d1732 ("serial: core: mark port as
initialized after successful IRQ change").
Nikola has been using autoconfig via setserial and reported a crash
similar to what I fixed in the earlier mentioned commit. Here I do the
same fixup for the autoconfig. I wasn't sure that this is the right
approach. Nikola confirmed that it fixes his crash.
Fixes: b3b576461864 ("tty: serial_core: convert uart_open to use tty_port_open")
Link: http://lkml.kernel.org/r/20180131072000.GD1853@localhost.localdomain
Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9f2068f35729948bde84d87a40d135015911345d upstream.
Add PCI ids for two variants of Brainboxes UC-260 quad port
PCI serial cards.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit fd63a8903a2c40425a9811c3371dd4d0f42c0ad3 upstream.
On our at91sam9260 based board the usart0 and usart1 ports report
their versions (ATMEL_US_VERSION) as 0x10302. This version is not
included in the current checks in the driver.
Signed-off-by: Jonas Danielsson <jonas@orbital-systems.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7842055bfce4bf0170d0f61df8b2add8399697be upstream.
When the TTY buffers fill up to the configured maximum, a system lockup
occurs:
[ 598.820128] INFO: rcu_preempt detected stalls on CPUs/tasks:
[ 598.825796] 0-...!: (1 GPs behind) idle=5a6/2/0 softirq=1974/1974 fqs=1
[ 598.832577] (detected by 3, t=62517 jiffies, g=296, c=295, q=126)
[ 598.838755] Task dump for CPU 0:
[ 598.841977] swapper/0 R running task 0 0 0 0x00000022
[ 598.849023] Call trace:
[ 598.851476] __switch_to+0x98/0xb0
[ 598.854870] (null)
This can be prevented by doing a dummy read of the RX data register.
This issue affects both HSCIF and SCIF ports. Reported for R-Car H3 ES2.0;
reproduced and fixed on H3 ES1.1. Probably affects other R-Car platforms
as well.
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable <stable@vger.kernel.org>
Tested-by: Nguyen Viet Dung <dung.nguyen.aj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 44117a1d1732c513875d5a163f10d9adbe866c08 upstream.
setserial changes the IRQ via uart_set_info(). It invokes
uart_shutdown() which free the current used IRQ and clear
TTY_PORT_INITIALIZED. It will then update the IRQ number and invoke
uart_startup() before returning to the caller leaving
TTY_PORT_INITIALIZED cleared.
The next open will crash with
| list_add double add: new=ffffffff839fcc98, prev=ffffffff839fcc98, next=ffffffff839fcc98.
since the close from the IOCTL won't free the IRQ (and clean the list)
due to the TTY_PORT_INITIALIZED check in uart_shutdown().
There is same pattern in uart_do_autoconfig() and I *think* it also
needs to set TTY_PORT_INITIALIZED there.
Is there a reason why uart_startup() does not set the flag by itself
after the IRQ has been acquired (since it is cleared in uart_shutdown)?
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 38b1f0fb42f772b8c9aac53593883a18ff5eb9d7 upstream.
The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS
lines, so only allow such wakeup method when the system actually has
RTS/CTS support.
Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b027e2298bd588d6fa36ed2eda97447fb3eac078 upstream.
There can be a race, if receive_buf call comes before
tty initialization completes in n_tty_open and tty->disc_data
may be NULL.
CPU0 CPU1
---- ----
000|n_tty_receive_buf_common() n_tty_open()
-001|n_tty_receive_buf2() tty_ldisc_open.isra.3()
-002|tty_ldisc_receive_buf(inline) tty_ldisc_setup()
Using ldisc semaphore lock in tty_init_dev till disc_data
initializes completely.
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e7e51dcf3b8a5f65c5653a054ad57eb2492a90d0 upstream.
The tty_ldisc_receive_buf() helper returns the number of bytes
processed so drop the bogus "not" from the kernel doc comment.
Fixes: 8d082cd300ab ("tty: Unify receive_buf() code paths")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 966031f340185eddd05affcf72b740549f056348 upstream.
We added support for EXTPROC back in 2010 in commit 26df6d13406d ("tty:
Add EXTPROC support for LINEMODE") and the intent was to allow it to
override some (all?) ICANON behavior. Quoting from that original commit
message:
There is a new bit in the termios local flag word, EXTPROC.
When this bit is set, several aspects of the terminal driver
are disabled. Input line editing, character echo, and mapping
of signals are all disabled. This allows the telnetd to turn
off these functions when in linemode, but still keep track of
what state the user wants the terminal to be in.
but the problem turns out that "several aspects of the terminal driver
are disabled" is a bit ambiguous, and you can really confuse the n_tty
layer by setting EXTPROC and then causing some of the ICANON invariants
to no longer be maintained.
This fixes at least one such case (TIOCINQ) becoming unhappy because of
the confusion over whether ICANON really means ICANON when EXTPROC is set.
This basically makes TIOCINQ match the case of read: if EXTPROC is set,
we ignore ICANON. Also, make sure to reset the ICANON state ie EXTPROC
changes, not just if ICANON changes.
Fixes: 26df6d13406d ("tty: Add EXTPROC support for LINEMODE")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzkaller <syzkaller@googlegroups.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit a4a3e061149f09c075f108b6f1cf04d9739a6bc2 ]
tty_ldisc_ref_wait() checks tty->ldisc under tty->ldisc_sem.
But if ldisc==NULL it releases them sem and reloads
tty->ldisc without holding the sem. This is wrong and
can lead to returning non-NULL ldisc without protection.
Don't reload tty->ldisc second time.
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 5362544bebe85071188dd9e479b5a5040841c895 ]
If tty_ldisc_open() fails in tty_set_ldisc(), it tries to go back
to the old discipline or N_TTY. But that can fail as well, in such
case it panics. This is not a graceful way to handle OOM.
Leave ldisc==NULL if all attempts fail instead.
Also use existing tty_ldisc_reinit() helper function instead of
tty_ldisc_restore(). Also don't WARN/BUG in tty_ldisc_reinit()
if N_TTY fails, which would have the same net effect of bringing
kernel down on OOM. Instead print a single line message about
what has happened.
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller@googlegroups.com
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b00bebbc301c8e1f74f230dc82282e56b7e7a6db ]
When kernel configuration SMP,PREEMPT and DEBUG_PREEMPT are enabled,
echo 1 >/proc/sys/kernel/sysrq
echo p >/proc/sysrq-trigger
kernel will print call trace as below:
sysrq: SysRq : Show Regs
BUG: using __this_cpu_read() in preemptible [00000000] code: sh/435
caller is __this_cpu_preempt_check+0x18/0x20
Call trace:
[<ffffff8008088e80>] dump_backtrace+0x0/0x1d0
[<ffffff8008089074>] show_stack+0x24/0x30
[<ffffff8008447970>] dump_stack+0x90/0xb0
[<ffffff8008463950>] check_preemption_disabled+0x100/0x108
[<ffffff8008463998>] __this_cpu_preempt_check+0x18/0x20
[<ffffff80084c9194>] sysrq_handle_showregs+0x1c/0x40
[<ffffff80084c9c7c>] __handle_sysrq+0x12c/0x1a0
[<ffffff80084ca140>] write_sysrq_trigger+0x60/0x70
[<ffffff8008251e00>] proc_reg_write+0x90/0xd0
[<ffffff80081f1788>] __vfs_write+0x48/0x90
[<ffffff80081f241c>] vfs_write+0xa4/0x190
[<ffffff80081f3354>] SyS_write+0x54/0xb0
[<ffffff80080833f0>] el0_svc_naked+0x24/0x28
This can be seen on a common board like an r-pi3.
This happens because when echo p >/proc/sysrq-trigger,
get_irq_regs() is called outside of IRQ context,
if preemption is enabled in this situation,kernel will
print the call trace. Since many prior discussions on
the mailing lists have made it clear that get_irq_regs
either just returns NULL or stale data when used outside
of IRQ context,we simply avoid calling it outside of
IRQ context.
Signed-off-by: Jibin Xu <jibin.xu@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 0ab84da2e076948c49d36197ee7d254125c53eab ]
The upper four bits of the XR17V35x fractional divisor register (DLD)
control general chip function (RS-485 direction pin polarity, multidrop
mode, XON/XOFF parity check, and fast IR mode). Don't allow these bits
to be clobbered when setting the baudrate.
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 3236a965486ba0c6043cf2c7b51943d8b382ae29 ]
This driver's ->rs485_config callback checks if SER_RS485_RTS_ON_SEND
and SER_RS485_RTS_AFTER_SEND have the same value. If they do, it means
the user has passed in invalid data with the TIOCSRS485 ioctl()
since RTS must have a different polarity when sending and when not
sending. In this case, rs485 mode is not enabled (the RS485_URA bit
is not set in the RS485 Enable Register) and this is supposed to be
signaled back to the user by clearing the SER_RS485_ENABLED bit in
struct serial_rs485 ... except a missing tilde character is preventing
that from happening.
Fixes: 28e3fb6c4dce ("serial: Add support for Fintek F81216A LPC to 4 UART")
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Cc: "Ji-Ze Hong (Peter Hong)" <hpeter@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3bfd1300abfe3adb18e84a89d97a0e82a22124bb upstream.
This device will be used in future Amazon EC2 instances as the primary
serial port (i.e., data sent to this port will be available via the
GetConsoleOuput [1] EC2 API).
[1] http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetConsoleOutput.html
Signed-off-by: Matt Wilson <msw@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit fd97e66c5529046e989a0879c3bb58fddb592c71 upstream.
The SuperIO will be configured at boot time by BIOS, but some BIOS
will not deactivate the SuperIO when the end of configuration. It'll
lead to mismatch for pdata->base_port in probe_setup_port(). So we'll
deactivate all SuperIO before activate special base_port in
fintek_8250_enter_key().
Tested on iBASE MI802.
Tested-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Reviewd-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2a71de2f7366fb1aec632116d0549ec56d6a3940 upstream.
Commit 348f9bb31c56 ("serial: omap: Fix RTS handling") sought to enable
auto RTS upon manual RTS assertion and disable it on deassertion.
However it seems the latter was done incorrectly, it clears all bits in
the Extended Features Register *except* auto RTS.
Fixes: 348f9bb31c56 ("serial: omap: Fix RTS handling")
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit a752ba18af8285e3eeda572f40dddaebff0c3621 ]
Even though most of its registers are 8-bit wide, the IRDA has two
16-bit registers that make it a 16-bit peripheral and not a 8-bit
peripheral with addresses shifted by one. Fix the registers offset in
the driver and the platform data regshift value.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd ]
On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.
Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 699a11ba7ec869b006623182881f2f1f5b4aea53 ]
With CONFIG_DYNAMIC_DEBUG if dyndbg enables debug output in
8250_port.c deadlock happens inevitably on UART IRQ handling.
That's the problematic execution path:
---------------------------->8------------------------
UART IRQ:
serial8250_interrupt() ->
serial8250_handle_irq(): lock "port->lock" ->
pr_debug() ->
serial8250_console_write(): bump in locked "port->lock".
OR (if above pr_debug() gets removed):
serial8250_tx_chars() ->
pr_debug() ->
serial8250_console_write(): bump in locked "port->lock".
---------------------------->8------------------------
So let's get rid of those not that much useful debug entries.
Discussed problem could be easily reproduced with QEMU for x86_64.
As well as this fix could be mimicked with muting of dynamic debug for
the problematic lines as simple as:
---------------------------->8------------------------
dyndbg="+p; file 8250_port.c line 1756 -p; file 8250_port.c line 1822 -p"
---------------------------->8------------------------
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Phillip Raffeck <phillip.raffeck@fau.de>
Cc: Anton Wuerfel <anton.wuerfel@fau.de>
Cc: "Matwey V. Kornilov" <matwey@sai.msu.ru>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Thor Thayer <tthayer@opensource.altera.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 1a5c2d1de7d35f5eb9793266237903348989502b ]
'request_irq()' and 'free_irq()' should be called with the same dev_id.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 9c4b60fe5313c125b1bf68ef04b0010512c27f2d ]
When struct moxa8250_board is allocated, then num_ports should
be initialized in order to use it later in moxa8250_remove.
Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 8a5a90a2a477b86a3dc2eaa5a706db9bfdd647ca upstream.
Sergey noticed a small but fatal mistake in __tty_insert_flip_char,
leading to an oops in an interrupt handler when using any serial
port.
The problem is that I accidentally took the tty_buffer pointer
before calling __tty_buffer_request_room(), which replaces the
buffer. This moves the pointer lookup to the right place after
allocating the new buffer space.
Fixes: 979990c62848 ("tty: improve tty_insert_flip_char() fast path")
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 065ea0a7afd64d6cf3464bdd1d8cd227527e2045 upstream.
While working on improving the fast path of tty_insert_flip_char(),
I noticed that by calling tty_buffer_request_room(), we needlessly
move to the separate flag buffer mode for the tty, even when all
characters use TTY_NORMAL as the flag.
This changes the code to call __tty_buffer_request_room() with the
correct flag, which will then allocate a regular buffer when it rounds
out of space but no special flags have been used. I'm guessing that
this is the behavior that Peter Hurley intended when he introduced
the compacted flip buffers.
Fixes: acc0f67f307f ("tty: Halve flip buffer GFP_ATOMIC memory consumption")
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 979990c6284814617d8f2179d197f72ff62b5d85 upstream.
kernelci.org reports a crazy stack usage for the VT code when CONFIG_KASAN
is enabled:
drivers/tty/vt/keyboard.c: In function 'kbd_keycode':
drivers/tty/vt/keyboard.c:1452:1: error: the frame size of 2240 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
The problem is that tty_insert_flip_char() gets inlined many times into
kbd_keycode(), and also into other functions, and each copy requires 128
bytes for stack redzone to check for a possible out-of-bounds access on
the 'ch' and 'flags' arguments that are passed into
tty_insert_flip_string_flags as a variable-length string.
This introduces a new __tty_insert_flip_char() function for the slow
path, which receives the two arguments by value. This completely avoids
the problem and the stack usage goes back down to around 100 bytes.
Without KASAN, this is also slightly better, as we don't have to
spill the arguments to the stack but can simply pass 'ch' and 'flag'
in registers, saving a few bytes in .text for each call site.
This should be backported to linux-4.0 or later, which first introduced
the stack sanitizer in the kernel.
Fixes: c420f167db8c ("kasan: enable stack instrumentation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6987dc8a70976561d22450b5858fc9767788cc1c upstream.
Only read access is checked before this call.
Actually, at the moment this is not an issue, as every in-tree arch does
the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU
to tell them apart, but this wasn't the case in the past and may happen
again on some odd arch in the future.
If anyone cares about 3.7 and earlier, this is a security hole (untested)
on real 80386 CPUs.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5f76895e4c712b1b5af450cf344389b8c53ac2c2 upstream.
When changing hardware control flow for a UART with dedicated RTS/CTS
pins, the new AUTORTS state is not immediately reflected in the
hardware, but only when RTS is raised. However, the serial core does
not call .set_mctrl() after .set_termios(), hence AUTORTS may only
become effective when the port is closed, and reopened later.
Note that this problem does not happen when manually using stty to
change CRTSCTS, as AUTORTS will work fine on next open.
To fix this, call .set_mctrl() from .set_termios() when dedicated
RTS/CTS pins are present, to refresh the AUTORTS or RTS state.
This is similar to what other drivers supporting AUTORTS do (e.g.
omap-serial).
Reported-by: Baumann, Christoph (C.) <cbaumann@visteon.com>
Fixes: 33f50ffc253854cf ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit be40597a1bc173bf9dadccdf5388b956f620ae8f upstream.
UARTn_FRAME_PARITY_ODD is 0x0300
UARTn_FRAME_PARITY_EVEN is 0x0200
So if the UART is configured for EVEN parity, it would be reported as ODD.
Fix it by correctly testing if the 2 bits are set.
Fixes: 3afbd89c9639 ("serial/efm32: add new driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3c9101766b502a0163d1d437fada5801cf616be2 upstream.
This patch fixes an issue that kernel panic happens when DMA is enabled
and we press enter key while the kernel booting on the serial console.
* An interrupt may occur after sci_request_irq().
* DMA transfer area is initialized by setup_timer() in sci_request_dma()
and used in interrupt.
If an interrupt occurred between sci_request_irq() and setup_timer() in
sci_request_dma(), DMA transfer area has not been initialized yet.
So, this patch changes the order of sci_request_irq() and
sci_request_dma().
Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.")
Signed-off-by: Takatoshi Akiyama <takatoshi.akiyama.kj@ps.hitachi-solutions.com>
[Shimoda changes the commit log]
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1e948479b3d63e3ac0ecca13cbf4921c7d17c168 upstream.
Make sure to deregister the SPI driver before releasing the tty driver
to avoid use-after-free in the SPI remove callback where the tty
devices are deregistered.
Fixes: 72d4724ea54c ("serial: ifx6x60: Add modem power off function in the platform reboot process")
Cc: Jun Chen <jun.d.chen@intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 4c4fc90964b1cf205a67df566cc82ea1731bcb00 upstream.
Commit fa01e2ca9f53 ("serial: 8250: Integrate Fintek into 8250_base")
modified the probing logic for PNP0501 devices, to remove a collision
between the generic 16550A driver and the Fintek driver, which reused
the same ACPI _HID.
The Fintek device probe is now incorporated into the common 8250 probe
path, and gets called for all discovered 16550A compatible devices,
including ones that are MMIO mapped rather than IO mapped. However,
the Fintek driver assumes the port base is a I/O address, and proceeds
to probe some arbitrary offsets above it.
This is generally a wrong thing to do, but on ARM systems (having no
native port I/O), this may result in faulting accesses of completely
unrelated MMIO regions in the PCI I/O space. Given that this is at
serial probe time, this results in hard to diagnose crashes at boot.
So let's restrict the Fintek probe to devices that we know are using
port I/O in the first place.
Fixes: fa01e2ca9f53 ("serial: 8250: Integrate Fintek into 8250_base")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ricardo Ribalda <ricardo.ribalda@gmail.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 77dae6134440420bac334581a3ccee94cee1c054 upstream.
While using emacs, cat or others' commands in konsole with recent
kernels, I have met many times that CTRL-C freeze konsole. After
konsole freeze I can't type anything, then I have to open a new one,
it is very annoying.
See bug report:
https://bugs.kde.org/show_bug.cgi?id=175283
The platform in that bug report is Solaris, but now the pty in linux
has the same problem or the same behavior as Solaris :)
It has high possibility to trigger the problem follow steps below:
Note: In my test, BigFile is a text file whose size is bigger than 1G
1:open konsole
1:cat BigFile
2:CTRL-C
After some digging, I find out the reason is that commit 1d1d14da12e7
("pty: Fix buffer flush deadlock") changes the behavior of pty_flush_buffer.
Thread A Thread B
-------- --------
1:n_tty_poll return POLLIN
2:CTRL-C trigger pty_flush_buffer
tty_buffer_flush
n_tty_flush_buffer
3:attempt to check count of chars:
ioctl(fd, TIOCINQ, &available)
available is equal to 0
4:read(fd, buffer, avaiable)
return 0
5:konsole close fd
Yes, I know we could use the same patch included in the BUG report as
a workaround for linux platform too. But I think the data in ldisc is
belong to application of another side, we shouldn't clear it when we
want to flush write buffer of this side in pty_flush_buffer. So I think
it is better to disable ldisc flush in pty_flush_buffer, because its new
hehavior bring no benefit except that it mess up the behavior between
POLLIN, and TIOCINQ or FIONREAD.
Also I find no flush_buffer function in others' tty driver has the
same behavior as current pty_flush_buffer.
Fixes: 1d1d14da12e7 ("pty: Fix buffer flush deadlock")
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 77e6fe7fd2b7cba0bf2f2dc8cde51d7b9a35bf74 upstream.
Make sure to actually suspend the device before returning after a failed
(or deferred) probe.
Note that autosuspend must be disabled before runtime pm is disabled in
order to balance the usage count due to a negative autosuspend delay as
well as to make the final put suspend the device synchronously.
Fixes: 388bc2622680 ("omap-serial: Fix the error handling in the omap_serial probe")
Cc: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 099bd73dc17ed77aa8c98323e043613b6e8f54fc upstream.
An unbalanced and misplaced synchronous put was used to suspend the
device on driver unbind, something which with a likewise misplaced
pm_runtime_disable leads to external aborts when an open port is being
removed.
Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa024010
...
[<c046e760>] (serial_omap_set_mctrl) from [<c046a064>] (uart_update_mctrl+0x50/0x60)
[<c046a064>] (uart_update_mctrl) from [<c046a400>] (uart_shutdown+0xbc/0x138)
[<c046a400>] (uart_shutdown) from [<c046bd2c>] (uart_hangup+0x94/0x190)
[<c046bd2c>] (uart_hangup) from [<c045b760>] (__tty_hangup+0x404/0x41c)
[<c045b760>] (__tty_hangup) from [<c045b794>] (tty_vhangup+0x1c/0x20)
[<c045b794>] (tty_vhangup) from [<c046ccc8>] (uart_remove_one_port+0xec/0x260)
[<c046ccc8>] (uart_remove_one_port) from [<c046ef4c>] (serial_omap_remove+0x40/0x60)
[<c046ef4c>] (serial_omap_remove) from [<c04845e8>] (platform_drv_remove+0x34/0x4c)
Fix this up by resuming the device before deregistering the port and by
suspending and disabling runtime pm only after the port has been
removed.
Also make sure to disable autosuspend before disabling runtime pm so
that the usage count is balanced and device actually suspended before
returning.
Note that due to a negative autosuspend delay being set in probe, the
unbalanced put would actually suspend the device on first driver unbind,
while rebinding and again unbinding would result in a negative
power.usage_count.
Fixes: 7e9c8e7dbf3b ("serial: omap: make sure to suspend device before remove")
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 768d64f491a530062ddad50e016fb27125f8bd7c upstream.
Driver should provide its own struct device for all DMA-mapping calls instead
of extracting device pointer from DMA engine channel. Although this is harmless
from the driver operation perspective on ARM architecture, it is always good
to use the DMA mapping API in a proper way. This patch fixes following DMA API
debug warning:
WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4
samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c0729058>] (check_sync+0x520/0x9f4)
[<c0729058>] (check_sync) from [<c072967c>] (debug_dma_sync_single_for_device+0x88/0xc8)
[<c072967c>] (debug_dma_sync_single_for_device) from [<c0803c10>] (s3c24xx_serial_start_tx_dma+0x100/0x2f8)
[<c0803c10>] (s3c24xx_serial_start_tx_dma) from [<c0804338>] (s3c24xx_serial_tx_chars+0x198/0x33c)
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 4e0f5cc65098ea32a1e77baae74215b9bd5276b1 upstream.
Otherwise the interconnect related code implementing PM runtime will
produce these errors on a failed probe:
omap_uart 48066000.serial: omap_device: omap_device_enable() called from invalid state 1
omap_uart 48066000.serial: use pm_runtime_put_sync_suspend() in driver?
Note that we now also need to check for priv in omap8250_runtime_suspend()
as it has not yet been registered if probe fails. And we need to use
pm_runtime_put_sync() to properly idle the device like we already do
in omap8250_remove().
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c130b666a9a711f985a0a44b58699ebe14bb7245 upstream.
Commit f209fa03fc9d ("serial: 8250_pci: Detach low-level driver during
PCI error recovery") introduces a potential use-after-free in case the
pciserial_init_ports call in serial8250_io_resume fails, which may
happen if a memory allocation fails or if the .init quirk failed for
whatever reason). If this happen, further pci_get_drvdata will return a
pointer to freed memory.
This patch reworks the PCI recovery resume hook to restore the old priv
structure in this case, which should be ok, since the ports were already
detached. Such error during recovery causes us to give up on the
recovery.
Fixes: f209fa03fc9d ("serial: 8250_pci: Detach low-level driver during PCI error recovery")
Reported-by: Michal Suchanek <msuchanek@suse.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b6ffcf21082300519bc4f9c3d24f61207cc9eae4 ]
UART uses as EDMA as dma engine on AM437x SoC and therefore, requires
OMAP_DMA_TX_KICK quirk just like AM33xx. So, enable OMAP_DMA_TX_KICK
quirk for AM437x platform as well. While at that, drop use of
of_machine_is_compatible() and instead pass quirks via device data.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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