Move both sysrq ctl_table and supported sysrq_sysctl_handler helper
function into drivers/tty/sysrq.c. Replaced the __do_proc_dointvec in
helper function with do_proc_dointvec_minmax as the former is local to
kernel/sysctl.c. Here we use the minmax version of do_proc_dointvec
because do_proc_dointvec is static and calling do_proc_dointvec_minmax
with a NULL min and max is the same as calling do_proc_dointvec.
This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Move this API to the canonical timer_*() namespace.
[ tglx: Redone against pre rc1 ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'printk-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Print more precise information about the printk log buffer memory
usage.
- Make sure that the sysrq title is shown on the console even when
deferred.
- Do not enable earlycon by `console=` which is meant to disable the
default console.
* tag 'printk-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: add dummy printk_force_console_enter/exit helpers
tty: sysrq: Use printk_force_console context on __handle_sysrq
printk: Introduce FORCE_CON flag
printk: Improve memory usage logging during boot
init: Don't proxy `console=` to earlycon
By using the printk_force_console the loglevel workaround can be removed.
The workaround existed to always send the sysrq header message to all
consoles not matter what was the current loglevel, but it won't work for
deferred messages, since the loglevel can be restore before the message
is printed, suppressing the message that wasn't supposed to be
suppressed by the workaround.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20241105-printk-loud-con-v2-2-bd3ecdf7b0e4@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
- Treewide conversion of of_property_for_each_u32() to drop internal
arguments making struct property opaque
- Add binding for Amlogic A4 SoC watchdog
- Fix constraints for AD7192 'single-channel' property
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Merge tag 'devicetree-fixes-for-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull more devicetree updates from Rob Herring:
"Most of this is a treewide change to of_property_for_each_u32() which
was small enough to do in one go before rc1 and avoids the need to
create of_property_for_each_u32_some_new_name().
- Treewide conversion of of_property_for_each_u32() to drop internal
arguments making struct property opaque
- Add binding for Amlogic A4 SoC watchdog
- Fix constraints for AD7192 'single-channel' property"
* tag 'devicetree-fixes-for-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
dt-bindings: iio: adc: ad7192: Fix 'single-channel' constraints
of: remove internal arguments from of_property_for_each_u32()
dt-bindings: watchdog: add support for Amlogic A4 SoCs
The of_property_for_each_u32() macro needs five parameters, two of which
are primarily meant as internal variables for the macro itself (in the
for() clause). Yet these two parameters are used by a few drivers, and this
can be considered misuse or at least bad practice.
Now that the kernel uses C11 to build, these two parameters can be avoided
by declaring them internally, thus changing this pattern:
struct property *prop;
const __be32 *p;
u32 val;
of_property_for_each_u32(np, "xyz", prop, p, val) { ... }
to this:
u32 val;
of_property_for_each_u32(np, "xyz", val) { ... }
However two variables cannot be declared in the for clause even with C11,
so declare one struct that contain the two variables we actually need. As
the variables inside this struct are not meant to be used by users of this
macro, give the struct instance the noticeable name "_it" so it is visible
during code reviews, helping to avoid new code to use it directly.
Most usages are trivially converted as they do not use those two
parameters, as expected. The non-trivial cases are:
- drivers/clk/clk.c, of_clk_get_parent_name(): easily doable anyway
- drivers/clk/clk-si5351.c, si5351_dt_parse(): this is more complex as the
checks had to be replicated in a different way, making code more verbose
and somewhat uglier, but I refrained from a full rework to keep as much
of the original code untouched having no hardware to test my changes
All the changes have been build tested. The few for which I have the
hardware have been runtime-tested too.
Reviewed-by: Andre Przywara <andre.przywara@arm.com> # drivers/clk/sunxi/clk-simple-gates.c, drivers/clk/sunxi/clk-sun8i-bus-gates.c
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # drivers/gpio/gpio-brcmstb.c
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> # drivers/irqchip/irq-atmel-aic-common.c
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # drivers/iio/adc/ti_am335x_adc.c
Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> # drivers/pwm/pwm-samsung.c
Acked-by: Richard Leitner <richard.leitner@linux.dev> # drivers/usb/misc/usb251xb.c
Acked-by: Mark Brown <broonie@kernel.org> # sound/soc/codecs/arizona.c
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> # sound/soc/codecs/arizona.c
Acked-by: Michael Ellerman <mpe@ellerman.id.au> # arch/powerpc/sysdev/xive/spapr.c
Acked-by: Stephen Boyd <sboyd@kernel.org> # clk
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Acked-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20240724-of_property_for_each_u32-v3-1-bea82ce429e2@bootlin.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
This enables the admin to abort the BPF scheduler and revert to CFS anytime.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
Rename console_replay_all() to console_try_replay_all() to make
clear that the implementation is best effort. Also, the function
should not be called in NMI context as it takes locks, so update
the comment in code.
Fixes: 693f75b91a ("printk: Add function to replay kernel log on consoles")
Fixes: 1b743485e2 ("tty/sysrq: Replay kernel log messages on consoles via sysrq")
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Shimoyashiki Taichi <taichi.shimoyashiki@sony.com>
Signed-off-by: Sreenath Vijayan <sreenath.vijayan@sony.com>
Link: https://lore.kernel.org/r/Zlguq/wU21Z8MqI4@sreenath.vijayan@sony.com
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
When terminal is unresponsive, one cannot use dmesg to view
the printk ring buffer messages. Also, syslog services may be
disabled, especially on embedded systems, to check the messages
after a reboot. In this scenario, replay the messages in printk
ring buffer on consoles via sysrq by pressing sysrq+R.
The console loglevel will determine which all kernel log messages
are displayed. The messages will be displayed only when
console_trylock() succeeds. Users could repeat the sysrq key when
it fails. If the owner of console subsystem lock is stuck,
repeating the key won't work.
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Shimoyashiki Taichi <taichi.shimoyashiki@sony.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sreenath Vijayan <sreenath.vijayan@sony.com>
Link: https://lore.kernel.org/r/cc3b9b1aae60a236c6aed1dc7b0ffa2c7cd1f183.1710220326.git.sreenath.vijayan@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This way we can do:
`echo _reisub > /proc/sysrq-trigger`
Instead of:
`for i in r e i s u b; do echo "$i" > /proc/sysrq-trigger; done;`
This can be very useful when trying to execute sysrq combo remotely
or from userspace. When sending keys in multiple separate writes,
userspace (eg. bash or ssh) can be killed before whole combo is completed.
Therefore putting all keys in single write is more robust approach.
Signed-off-by: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231120111451.527952-1-tomas.mudrunka@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The smp_processor_id() shouldn't be called from preemptible code.
Instead use get_cpu() and put_cpu() which disables preemption in
addition to getting the processor id. Enable preemption back after
calling schedule_work() to make sure that the work gets scheduled on all
cores other than the current core. We want to avoid a scenario where
current core's stack trace is printed multiple times and one core's
stack trace isn't printed because of scheduling of current task.
This fixes the following bug:
[ 119.143590] sysrq: Show backtrace of all active CPUs
[ 119.143902] BUG: using smp_processor_id() in preemptible [00000000] code: bash/873
[ 119.144586] caller is debug_smp_processor_id+0x20/0x30
[ 119.144827] CPU: 6 PID: 873 Comm: bash Not tainted 5.10.124-dirty #3
[ 119.144861] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-1 07/22/2023
[ 119.145053] Call trace:
[ 119.145093] dump_backtrace+0x0/0x1a0
[ 119.145122] show_stack+0x18/0x70
[ 119.145141] dump_stack+0xc4/0x11c
[ 119.145159] check_preemption_disabled+0x100/0x110
[ 119.145175] debug_smp_processor_id+0x20/0x30
[ 119.145195] sysrq_handle_showallcpus+0x20/0xc0
[ 119.145211] __handle_sysrq+0x8c/0x1a0
[ 119.145227] write_sysrq_trigger+0x94/0x12c
[ 119.145247] proc_reg_write+0xa8/0xe4
[ 119.145266] vfs_write+0xec/0x280
[ 119.145282] ksys_write+0x6c/0x100
[ 119.145298] __arm64_sys_write+0x20/0x30
[ 119.145315] el0_svc_common.constprop.0+0x78/0x1e4
[ 119.145332] do_el0_svc+0x24/0x8c
[ 119.145348] el0_svc+0x10/0x20
[ 119.145364] el0_sync_handler+0x134/0x140
[ 119.145381] el0_sync+0x180/0x1c0
Cc: jirislaby@kernel.org
Cc: stable@vger.kernel.org
Fixes: 47cab6a722 ("debug lockups: Improve lockup detection, fix generic arch fallback")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20231009162021.3607632-1-usama.anjum@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big set of tty and serial driver changes for 6.6-rc1.
Lots of cleanups in here this cycle, and some driver updates. Short
summary is:
- Jiri's continued work to make the tty code and apis be a bit more
sane with regards to modern kernel coding style and types
- cpm_uart driver updates
- n_gsm updates and fixes
- meson driver updates
- sc16is7xx driver updates
- 8250 driver updates for different hardware types
- qcom-geni driver fixes
- tegra serial driver change
- stm32 driver updates
- synclink_gt driver cleanups
- tty structure size reduction
All of these have been in linux-next this week with no reported issues.
The last bit of cleanups from Jiri and the tty structure size reduction
came in last week, a bit late but as they were just style changes and
size reductions, I figured they should get into this merge cycle so that
others can work on top of them with no merge conflicts.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here is the big set of tty and serial driver changes for 6.6-rc1.
Lots of cleanups in here this cycle, and some driver updates. Short
summary is:
- Jiri's continued work to make the tty code and apis be a bit more
sane with regards to modern kernel coding style and types
- cpm_uart driver updates
- n_gsm updates and fixes
- meson driver updates
- sc16is7xx driver updates
- 8250 driver updates for different hardware types
- qcom-geni driver fixes
- tegra serial driver change
- stm32 driver updates
- synclink_gt driver cleanups
- tty structure size reduction
All of these have been in linux-next this week with no reported
issues. The last bit of cleanups from Jiri and the tty structure size
reduction came in last week, a bit late but as they were just style
changes and size reductions, I figured they should get into this merge
cycle so that others can work on top of them with no merge conflicts"
* tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
tty: shrink the size of struct tty_struct by 40 bytes
tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw()
tty: n_tty: extract ECHO_OP processing to a separate function
tty: n_tty: unify counts to size_t
tty: n_tty: use u8 for chars and flags
tty: n_tty: simplify chars_in_buffer()
tty: n_tty: remove unsigned char casts from character constants
tty: n_tty: move newline handling to a separate function
tty: n_tty: move canon handling to a separate function
tty: n_tty: use MASK() for masking out size bits
tty: n_tty: make n_tty_data::num_overrun unsigned
tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun()
tty: n_tty: use 'num' for writes' counts
tty: n_tty: use output character directly
tty: n_tty: make flow of n_tty_receive_buf_common() a bool
Revert "tty: serial: meson: Add a earlycon for the T7 SoC"
Documentation: devices.txt: Fix minors for ttyCPM*
Documentation: devices.txt: Remove ttySIOC*
Documentation: devices.txt: Remove ttyIOC*
serial: 8250_bcm7271: improve bcm7271 8250 port
...
All callers of show_mem() pass 0 and NULL, so we can remove the two
arguments by directly calling __show_mem(0, NULL, MAX_NR_ZONES - 1) in
show_mem().
Link: https://lkml.kernel.org/r/20230630062253.189440-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Using switch with range cases makes the code more aligned and readable.
Expand also that 36 as explicit addition of 10 + 26 to make the source
of the constant more obvious.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230712081811.29004-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Propagate u8 more from the bottom to the interface, so that sysrq
callers (usually drivers) see that u8 is expected.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230712081811.29004-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The passed parameter to sysrq handlers is a key (a character). So change
the type from 'int' to 'u8'. Let it specifically be 'u8' for two
reasons:
* unsigned: unsigned values come from the upper layers (devices) and the
tty layer assumes unsigned on most places, and
* 8-bit: as that what's supposed to be one day in all the layers built
on the top of tty. (Currently, we use mostly 'unsigned char' and
somewhere still only 'char'. (But that also translates to the former
thanks to -funsigned-char.))
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Zqiang <qiang.zhang1211@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de> # DRM
Acked-by: WANG Xuerui <git@xen0n.name> # loongarch
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20230712081811.29004-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'i' is a too generic name for something which carries a 'loglevel'. Name
it as such and make it 'u8', the same as key will become in the next
patches.
Note that we are not stripping any high bits away, 'key' is given only
8bit values.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230712081811.29004-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown". After a timer is set to this state, then it can no
longer be re-armed.
The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed. It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.
This was created by using a coccinelle script and the following
commands:
$ cat timer.cocci
@@
expression ptr, slab;
identifier timer, rfield;
@@
(
- del_timer(&ptr->timer);
+ timer_shutdown(&ptr->timer);
|
- del_timer_sync(&ptr->timer);
+ timer_shutdown_sync(&ptr->timer);
)
... when strict
when != ptr->timer
(
kfree_rcu(ptr, rfield);
|
kmem_cache_free(slab, ptr);
|
kfree(ptr);
)
$ spatch timer.cocci . > /tmp/t.patch
$ patch -p1 < /tmp/t.patch
Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2bb2b7b57f.
The testing of 5.19 release candidates revealed missing synchronization
between early and regular console functionality.
It would be possible to start the console kthreads later as a workaround.
But it is clear that console lock serialized console drivers between
each other. It opens a big area of possible problems that were not
considered by people involved in the development and review.
printk() is crucial for debugging kernel issues and console output is
very important part of it. The number of consoles is huge and a proper
review would take some time. As a result it need to be reverted for 5.19.
Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220623145157.21938-7-pmladek@suse.com
Here is the big set of tty and serial driver updates for 5.19-rc1.
Lots of tiny cleanups in here, the major stuff is:
- termbit cleanups and unification by Ilpo. A much needed
change that goes a long way to making things simpler for all
of the different arches
- tty documentation cleanups and movements to their own place in
the documentation tree
- old tty driver cleanups and fixes from Jiri to bring some
existing drivers into the modern world
- RS485 cleanups and unifications to make it easier for
individual drivers to support this mode instead of having to
duplicate logic in each driver
- Lots of 8250 driver updates and additions
- new device id additions
- n_gsm continued fixes and cleanups
- other minor serial driver updates and cleanups
All of these have been in linux-next for weeks with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty and serial driver updates from Greg KH:
"Here is the big set of tty and serial driver updates for 5.19-rc1.
Lots of tiny cleanups in here, the major stuff is:
- termbit cleanups and unification by Ilpo. A much needed change that
goes a long way to making things simpler for all of the different
arches
- tty documentation cleanups and movements to their own place in the
documentation tree
- old tty driver cleanups and fixes from Jiri to bring some existing
drivers into the modern world
- RS485 cleanups and unifications to make it easier for individual
drivers to support this mode instead of having to duplicate logic
in each driver
- Lots of 8250 driver updates and additions
- new device id additions
- n_gsm continued fixes and cleanups
- other minor serial driver updates and cleanups
All of these have been in linux-next for weeks with no reported issues"
* tag 'tty-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (166 commits)
tty: Rework receive flow control char logic
pcmcia: synclink_cs: Don't allow CS5-6
serial: stm32-usart: Correct CSIZE, bits, and parity
serial: st-asc: Sanitize CSIZE and correct PARENB for CS7
serial: sifive: Sanitize CSIZE and c_iflag
serial: sh-sci: Don't allow CS5-6
serial: txx9: Don't allow CS5-6
serial: rda-uart: Don't allow CS5-6
serial: digicolor-usart: Don't allow CS5-6
serial: uartlite: Fix BRKINT clearing
serial: cpm_uart: Fix build error without CONFIG_SERIAL_CPM_CONSOLE
serial: core: Do stop_rx in suspend path for console if console_suspend is disabled
tty: serial: qcom-geni-serial: Remove uart frequency table. Instead, find suitable frequency with call to clk_round_rate.
dt-bindings: serial: renesas,em-uart: Add RZ/V2M clock to access the registers
serial: 8250_fintek: Check SER_RS485_RTS_* only with RS485
Revert "serial: 8250_mtk: Make sure to select the right FEATURE_SEL"
serial: msm_serial: disable interrupts in __msm_console_write()
serial: meson: acquire port->lock in startup()
serial: 8250_dw: Use dev_err_probe()
serial: 8250_dw: Use devm_add_action_or_reset()
...
Once kthread printing is available, console printing will no longer
occur in the context of the printk caller. However, there are some
special contexts where it is desirable for the printk caller to
directly print out kernel messages. Using pr_flush() to wait for
threaded printers is only possible if the caller is in a sleepable
context and the kthreads are active. That is not always the case.
Introduce printk_prefer_direct_enter() and printk_prefer_direct_exit()
functions to explicitly (and globally) activate/deactivate preferred
direct console printing. The term "direct console printing" refers to
printing to all enabled consoles from the context of the printk
caller. The term "prefer" is used because this type of printing is
only best effort. If the console is currently locked or other
printers are already actively printing, the printk caller will need
to rely on the other contexts to handle the printing.
This preferred direct printing is how all printing has been handled
until now (unless it was explicitly deferred).
When kthread printing is introduced, there may be some unanticipated
problems due to kthreads being unable to flush important messages.
In order to minimize such risks, preferred direct printing is
activated for the primary important messages when the system
experiences general types of major errors. These are:
- emergency reboot/shutdown
- cpu and rcu stalls
- hard and soft lockups
- hung tasks
- warn
- sysrq
Note that since kthread printing does not yet exist, no behavior
changes result from this commit. This is only implementing the
counter and marking the various places where preferred direct
printing is active.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org> # for RCU
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220421212250.565456-13-john.ogness@linutronix.de
The definition of sysrq_key_table's elements, like sysrq_thaw_op and
sysrq_showallcpus_op are not consistent with sysrq_ftrace_dump_op,
Consistency makes code more readable.
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Junwen Wu <wudaemon@gmail.com>
Link: https://lore.kernel.org/r/20220418153703.97705-1-wudaemon@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big set of tty and serial driver updates for 5.16-rc1.
Nothing major in here at all, just lots of tiny serial and tty driver
updates for various reported things, and some good cleanups. These
include:
- more good tty api cleanups from Jiri
- stm32 serial driver updates
- softlockup fix for non-preempt systems under high serial load
- rpmsg serial driver update
- 8250 drivers updates and fixes
- n_gsm line discipline fixes and updates as people are finally
starting to use it.
All of these have been in linux-next for a while now with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial driver updates from Greg KH:
"Here is the big set of tty and serial driver updates for 5.16-rc1.
Nothing major in here at all, just lots of tiny serial and tty driver
updates for various reported things, and some good cleanups. These
include:
- more good tty api cleanups from Jiri
- stm32 serial driver updates
- softlockup fix for non-preempt systems under high serial load
- rpmsg serial driver update
- 8250 drivers updates and fixes
- n_gsm line discipline fixes and updates as people are finally
starting to use it.
All of these have been in linux-next for a while now with no reported
issues"
* tag 'tty-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (86 commits)
tty: Fix extra "not" in TTY_DRIVER_REAL_RAW description
serial: cpm_uart: Protect udbg definitions by CONFIG_SERIAL_CPM_CONSOLE
tty: rpmsg: Define tty name via constant string literal
tty: rpmsg: Add pr_fmt() to prefix messages
tty: rpmsg: Use dev_err_probe() in ->probe()
tty: rpmsg: Unify variable used to keep an error code
tty: rpmsg: Assign returned id to a local variable
serial: stm32: push DMA RX data before suspending
serial: stm32: terminate / restart DMA transfer at suspend / resume
serial: stm32: rework RX dma initialization and release
serial: 8250_pci: Remove empty stub pci_quatech_exit()
serial: 8250_pci: Replace custom pci_match_id() implementation
serial: xilinx_uartps: Fix race condition causing stuck TX
serial: sunzilog: Mark sunzilog_putchar() __maybe_unused
Revert "tty: hvc: pass DMA capable memory to put_chars()"
Revert "virtio-console: remove unnecessary kmemdup()"
serial: 8250_pci: Replace dev_*() by pci_*() macros
serial: 8250_pci: Get rid of redundant 'else' keyword
serial: 8250_pci: Refactor the loop in pci_ite887x_init()
tty: add rpmsg driver
...
Currently show_workqueue_state shows the state of all workqueues and of
all worker pools. In certain cases we may need to dump state of only a
specific workqueue or worker pool. For example in destroy_workqueue we
only need to show state of the workqueue which is getting destroyed.
So rename show_workqueue_state to show_all_workqueues(to signify it
dumps state of all busy workqueues) and divide it into more granular
functions (show_one_workqueue and show_one_worker_pool), that would show
states of individual workqueues and worker pools and can be used in
cases such as the one mentioned above.
Also, as mentioned earlier, make destroy_workqueue dump data pertaining
to only the workqueue that is being destroyed and make user(s) of
earlier interface(show_workqueue_state), use new interface
(show_all_workqueues).
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Replace the obsolete and ambiguos macro in_irq() with new
macro in_hardirq().
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Link: https://lore.kernel.org/r/20210814005033.2381-1-changbin.du@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All slots in sysrq_key_table[] are either used, reserved or at least
commented with their intended use. This patch adds capital letter versions
available, which means adding 26 more entries.
For already existing SysRq operations the user presses Alt-SysRq-<key>, and
for the newly added ones Alt-Shift-SysRq-<key>.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20200818112825.6445-2-andrzej.p@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can also thaw non-block file systems. Remove the CONFIG_BLOCK in
sysrq.c after making the prototype available unconditionally.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
again well known show_stack().
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Show the stack trace on a CPU with the same log level as "CPU%d" header.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-45-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The user is not supposed to thinker with the underlying sysrq_key_op.
Make that explicit by adding a handful of const notations.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://lore.kernel.org/r/20200513214351.2138580-2-emil.l.velikov@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Export a pointer to the sysrq_get_key_op(). This way we can cleanly
unregister it, instead of the current solutions of modifuing it inplace.
Since __sysrq_get_key_op() is no longer used externally, let's make it
a static function.
This patch will allow us to limit access to each and every sysrq op and
constify the sysrq handling.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://lore.kernel.org/r/20200513214351.2138580-1-emil.l.velikov@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many embedded boards have a disconnected TTL level serial which can
generate some garbage that can lead to spurious false sysrq detects.
Currently, sysrq can be either completely disabled for serial console
or always disabled (with CONFIG_MAGIC_SYSRQ_SERIAL), since
commit 732dbf3a61 ("serial: do not accept sysrq characters via serial port")
At Arista, we have such boards that can generate BREAK and random
garbage. While disabling sysrq for serial console would solve
the problem with spurious false sysrq triggers, it's also desirable
to have a way to enable sysrq back.
Having the way to enable sysrq was beneficial to debug lockups with
a manual investigation in field and on the other side preventing false
sysrq detections.
As a preparation to add sysrq_toggle_support() call into uart,
remove a private copy of sysrq_enabled from sysctl - it should reflect
the actual status of sysrq.
Furthermore, the private copy isn't correct already in case
sysrq_always_enabled is true. So, remove __sysrq_enabled and use a
getter-helper sysrq_mask() to check sysrq_key_op enabled status.
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20200302175135.269397-2-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysrq_toggle_support() can be called in parallel, in return calling
input_(un)register_handler(), which fortunately is safe to call
in parallel and regardless of registered/unregistered status of
sysrq_handler.
Remove sysrq_handler_registered as it doesn't have any function there
and may confuse reader about possible race.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-2-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When kernel panic happens, it will first print the panic call stack,
then the ending msg like:
[ 35.743249] ---[ end Kernel panic - not syncing: Fatal exception
[ 35.749975] ------------[ cut here ]------------
The above message are very useful for debugging.
But if system is configured to not reboot on panic, say the
"panic_timeout" parameter equals 0, it will likely print out many noisy
message like WARN() call stack for each and every CPU except the panic
one, messages like below:
WARNING: CPU: 1 PID: 280 at kernel/sched/core.c:1198 set_task_cpu+0x183/0x190
Call Trace:
<IRQ>
try_to_wake_up
default_wake_function
autoremove_wake_function
__wake_up_common
__wake_up_common_lock
__wake_up
wake_up_klogd_work_func
irq_work_run_list
irq_work_tick
update_process_times
tick_sched_timer
__hrtimer_run_queues
hrtimer_interrupt
smp_apic_timer_interrupt
apic_timer_interrupt
For people working in console mode, the screen will first show the panic
call stack, but immediately overridden by these noisy extra messages,
which makes debugging much more difficult, as the original context gets
lost on screen.
Also these noisy messages will confuse some users, as I have seen many bug
reporters posted the noisy message into bugzilla, instead of the real
panic call stack and context.
Adding a flag "suppress_printk" which gets set in panic() to avoid those
noisy messages, without changing current kernel behavior that both panic
blinking and sysrq magic key can work as is, suggested by Petr Mladek.
To verify this, make sure kernel is not configured to reboot on panic and
in console
# echo c > /proc/sysrq-trigger
to see if console only prints out the panic call stack.
Link: http://lkml.kernel.org/r/1551430186-24169-1-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Systems which don't provide arch_trigger_cpumask_backtrace() will
invoke showacpu() from a smp_call_function() function which is invoked
with disabled interrupts even on -RT systems.
The function acquires the show_lock lock which only purpose is to
ensure that the CPUs don't print simultaneously. Otherwise the
output would clash and it would be hard to tell the output from CPUx
apart from CPUy.
On -RT the spin_lock() can not be acquired from this context. A
raw_spin_lock() is required. It will introduce the system's latency
by performing the sysrq request and other CPUs will block on the lock
until the request is done. This is okay because the user asked for a
backtrace of all active CPUs and under "normal circumstances in
production" this path should not be triggered.
Signed-off-by: Julien Grall <julien.grall@arm.com>
[bigeasy@linuxtronix.de: commit description]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The commit 97f5f0cd8c ("Input: implement SysRq as a separate input
handler") added pr_fmt() definition. It caused a duplicated message
prefix in the sysrq header messages, for example:
[ 177.053931] sysrq: SysRq : Show backtrace of all active CPUs
[ 742.864776] sysrq: SysRq : HELP : loglevel(0-9) reboot(b) crash(c)
Fixes: 97f5f0cd8c ("Input: implement SysRq as a separate input handler")
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sysrq header line is printed with an increased loglevel
to provide users some positive feedback.
The original loglevel is not restored when the sysrq operation
is disabled. This bug was introduced in 2.6.12 (pre-git-history)
by the commit ("Allow admin to enable only some of the Magic-Sysrq
functions").
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysrq_do_reset() is called in softirq context, so it cannot call
sync() directly. Instead, call orderly_reboot(), which creates a work
item to run /sbin/reboot, or do emergency_sync and restart if the
command fails.
Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysrq_handle_crash() currently forces a crash by dereferencing a
NULL pointer, which is undefined behavior in C. Just call panic()
instead, which is simpler and doesn't depend on compiler specific
handling of the undefined behavior.
Remove the comment on why the RCU lock needs to be released, it isn't
accurate anymore since the crash now isn't handled by the page fault
handler (for reference: the comment was added by commit 984cf355ae
("sysrq: Fix warning in sysrq generated crash.")). Releasing the lock
is still good practice though.
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
bl_idle_init() doesn't do that, so fix it.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
