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
...
Eric has pointed out that we still have 3 users of do_each_thread().
Change them to use for_each_process_thread() and kill this helper.
There is a subtle change, after do_each_thread/while_each_thread g == t ==
&init_task, while after for_each_process_thread() they both point to
nowhere, but this doesn't matter.
> Why is for_each_process_thread() better than do_each_thread()?
Say, for_each_process_thread() is rcu safe, do_each_thread() is not.
And certainly
for_each_process_thread(p, t) {
do_something(p, t);
}
looks better than
do_each_thread(p, t) {
do_something(p, t);
} while_each_thread(p, t);
And again, there are only 3 users of this awkward helper left. It should
have been killed years ago and in fact I thought it had already been
killed. It uses while_each_thread() which needs some changes.
Link: https://lkml.kernel.org/r/20230817163708.GA8248@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jiri Slaby <jirislaby@kernel.org> # tty/serial
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
tty_read() is supposed to return ssize_t. It takes the return value from
iterate_tty_read(). That currently returns int. On the top of that,
iterate_tty_write() already returns ssize_t. So switch
iterate_tty_read() to ssize_t too, so that all three are consistent.
This means 'i' in tty_read() changes its type too. And while changing
that, rename this generic 'i' to more dedicated 'ret'.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230810091510.13006-25-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty/serial driver updates from Greg KH:
"Here is the big set of tty/serial driver updates for 6.5-rc1.
Included in here are:
- tty_audit code cleanups from Jiri
- more 8250 cleanups from Ilpo
- samsung_tty driver bugfixes
- 8250 lock port updates
- usual fsl_lpuart driver updates and fixes
- other small serial driver fixes and updates, full details in the
shortlog
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (58 commits)
tty_audit: make data of tty_audit_log() const
tty_audit: make tty pointers in exposed functions const
tty_audit: make icanon a bool
tty_audit: invert the condition in tty_audit_log()
tty_audit: use kzalloc() in tty_audit_buf_alloc()
tty_audit: use TASK_COMM_LEN for task comm
Revert "8250: add support for ASIX devices with a FIFO bug"
serial: atmel: don't enable IRQs prematurely
tty: serial: Add Nuvoton ma35d1 serial driver support
tty: serial: fsl_lpuart: add earlycon for imx8ulp platform
tty: serial: imx: fix rs485 rx after tx
selftests: tty: add selftest for tty timestamp updates
tty: tty_io: update timestamps on all device nodes
tty: fix hang on tty device with no_room set
serial: core: fix -EPROBE_DEFER handling in init
serial: 8250_omap: Use force_suspend and resume for system suspend
tty: serial: samsung_tty: Use abs() to simplify some code
tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk
tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error
serial: 8250: Apply FSL workarounds also without SERIAL_8250_CONSOLE
...
User space applications watch for timestamp changes on character device
files in order to determine idle time of a given terminal session. For
example, "w" program uses this information to populate the IDLE column
of its output [1]. Similarly, systemd-logind has optional feature where
it uses atime of the tty character device to determine if there was
activity on the terminal associated with the logind's session object. If
there was no activity for a configured period of time then logind will
terminate such session [2].
Now, usually (e.g. bash running on the terminal) the use of the terminal
will update timestamps (atime and mtime) on the corresponding terminal
character device. However, if access to the terminal, e.g. /dev/pts/0,
is performed through magic character device /dev/tty then such access
obviously changes the state of the terminal, however timestamps on the
device that correspond to the terminal (/dev/pts/0) are not updated.
This patch makes sure that we update timestamps on *all* character
devices that correspond to the given tty, because outside observers (w,
systemd-logind) are maybe checking these timestamps. Obviously, they can
not check timestamps on /dev/tty as that has per-process meaning.
[1] https://gitlab.com/procps-ng/procps/-/blob/v4.0.0/w.c#L286
[2] https://github.com/systemd/systemd/blob/v252/NEWS#L477
Signed-off-by: Michal Sekletar <msekleta@redhat.com>
Message-ID: <20230613172107.78138-1-msekleta@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Greg KH:
"Here is the large set of driver core changes for 6.4-rc1.
Once again, a busy development cycle, with lots of changes happening
in the driver core in the quest to be able to move "struct bus" and
"struct class" into read-only memory, a task now complete with these
changes.
This will make the future rust interactions with the driver core more
"provably correct" as well as providing more obvious lifetime rules
for all busses and classes in the kernel.
The changes required for this did touch many individual classes and
busses as many callbacks were changed to take const * parameters
instead. All of these changes have been submitted to the various
subsystem maintainers, giving them plenty of time to review, and most
of them actually did so.
Other than those changes, included in here are a small set of other
things:
- kobject logging improvements
- cacheinfo improvements and updates
- obligatory fw_devlink updates and fixes
- documentation updates
- device property cleanups and const * changes
- firwmare loader dependency fixes.
All of these have been in linux-next for a while with no reported
problems"
* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
device property: make device_property functions take const device *
driver core: update comments in device_rename()
driver core: Don't require dynamic_debug for initcall_debug probe timing
firmware_loader: rework crypto dependencies
firmware_loader: Strip off \n from customized path
zram: fix up permission for the hot_add sysfs file
cacheinfo: Add use_arch[|_cache]_info field/function
arch_topology: Remove early cacheinfo error message if -ENOENT
cacheinfo: Check cache properties are present in DT
cacheinfo: Check sib_leaf in cache_leaves_are_shared()
cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
cacheinfo: Add arm64 early level initializer implementation
cacheinfo: Add arch specific early level initializer
tty: make tty_class a static const structure
driver core: class: remove struct class_interface * from callbacks
driver core: class: mark the struct class in struct class_interface constant
driver core: class: make class_register() take a const *
driver core: class: mark class_release() as taking a const *
driver core: remove incorrect comment for device_create*
MIPS: vpe-cmp: remove module owner pointer from struct class usage.
...
If userspace races tcsetattr() with a write, the drained condition
might not be guaranteed by the kernel. There is a race window after
checking Tx is empty before tty_set_termios() takes termios_rwsem for
write. During that race window, more characters can be queued by a
racing writer.
Any ongoing transmission might produce garbage during HW's
->set_termios() call. The intent of TCSADRAIN/FLUSH seems to be
preventing such a character corruption. If those flags are set, take
tty's write lock to stop any writer before performing the lower layer
Tx empty check and wait for the pending characters to be sent (if any).
The initial wait for all-writers-done must be placed outside of tty's
write lock to avoid deadlock which makes it impossible to use
tty_wait_until_sent(). The write lock is retried if a racing write is
detected.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230317113318.31327-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Greg KH:
"Here is the set of driver core and kernfs changes for 6.2-rc1.
The "big" change in here is the addition of a new macro,
container_of_const() that will preserve the "const-ness" of a pointer
passed into it.
The "problem" of the current container_of() macro is that if you pass
in a "const *", out of it can comes a non-const pointer unless you
specifically ask for it. For many usages, we want to preserve the
"const" attribute by using the same call. For a specific example, this
series changes the kobj_to_dev() macro to use it, allowing it to be
used no matter what the const value is. This prevents every subsystem
from having to declare 2 different individual macros (i.e.
kobj_const_to_dev() and kobj_to_dev()) and having the compiler enforce
the const value at build time, which having 2 macros would not do
either.
The driver for all of this have been discussions with the Rust kernel
developers as to how to properly mark driver core, and kobject,
objects as being "non-mutable". The changes to the kobject and driver
core in this pull request are the result of that, as there are lots of
paths where kobjects and device pointers are not modified at all, so
marking them as "const" allows the compiler to enforce this.
So, a nice side affect of the Rust development effort has been already
to clean up the driver core code to be more obvious about object
rules.
All of this has been bike-shedded in quite a lot of detail on lkml
with different names and implementations resulting in the tiny version
we have in here, much better than my original proposal. Lots of
subsystem maintainers have acked the changes as well.
Other than this change, included in here are smaller stuff like:
- kernfs fixes and updates to handle lock contention better
- vmlinux.lds.h fixes and updates
- sysfs and debugfs documentation updates
- device property updates
All of these have been in the linux-next tree for quite a while with
no problems"
* tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (58 commits)
device property: Fix documentation for fwnode_get_next_parent()
firmware_loader: fix up to_fw_sysfs() to preserve const
usb.h: take advantage of container_of_const()
device.h: move kobj_to_dev() to use container_of_const()
container_of: add container_of_const() that preserves const-ness of the pointer
driver core: fix up missed drivers/s390/char/hmcdrv_dev.c class.devnode() conversion.
driver core: fix up missed scsi/cxlflash class.devnode() conversion.
driver core: fix up some missing class.devnode() conversions.
driver core: make struct class.devnode() take a const *
driver core: make struct class.dev_uevent() take a const *
cacheinfo: Remove of_node_put() for fw_token
device property: Add a blank line in Kconfig of tests
device property: Rename goto label to be more precise
device property: Move PROPERTY_ENTRY_BOOL() a bit down
device property: Get rid of __PROPERTY_ENTRY_ARRAY_EL*SIZE*()
kernfs: fix all kernel-doc warnings and multiple typos
driver core: pass a const * into of_device_uevent()
kobject: kset_uevent_ops: make name() callback take a const *
kobject: kset_uevent_ops: make filter() callback take a const *
kobject: make kobject_namespace take a const *
...
Pull tty/serial driver updates from Greg KH:
"Here is the "big" set of tty/serial driver changes for 6.2-rc1.
As in previous kernel releases, nothing big here at all, just some
small incremental serial/tty layer cleanups and some individual driver
additions and fixes. Highlights are:
- serial helper macros from Jiri Slaby to reduce the amount of
duplicated code in serial drivers
- api cleanups and consolidations from Ilpo Järvinen in lots of
serial drivers
- the usual set of n_gsm fixes from Daniel Starke as that code gets
exercised more
- TIOCSTI is finally able to be disabled if requested (security
hardening feature from Kees Cook)
- fsl_lpuart driver fixes and features added
- other small serial driver additions and fixes
All of these have been in linux-next for a while with no reported
problems"
* tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits)
serial: atmel: don't stop the transmitter when doing PIO
serial: atmel: cleanup atmel_start+stop_tx()
tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API
serial: sunsab: Fix error handling in sunsab_init()
serial: altera_uart: fix locking in polling mode
serial: pch: Fix PCI device refcount leak in pch_request_dma()
tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused
tty: serial: fsl_lpuart: Add runtime pm support
tty: serial: fsl_lpuart: enable wakeup source for lpuart
serdev: Replace poll loop by readx_poll_timeout() macro
tty: synclink_gt: unwind actions in error path of net device open
serial: stm32: move dma_request_chan() before clk_prepare_enable()
dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity'
serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.
serial: amba-pl011: avoid SBSA UART accessing DMACR register
tty: serial: altera_jtaguart: remove struct altera_jtaguart
tty: serial: altera_jtaguart: use uart_port::read_status_mask
tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs
tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars()
n_tty: Rename tail to old_tail in n_tty_read()
...
show_cons_active() uses the console_lock to gather information
on registered consoles. It requires that no consoles are unregistered
until it is finished. The console_list_lock should be used because
list synchronization responsibility will be removed from the
console_lock in a later change.
Note, the console_lock is still needed to serialize the device()
callback with other console operations.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-34-john.ogness@linutronix.de
At each login the user forces the kernel to create a new terminal and
allocate up to ~1Kb memory for the tty-related structures.
By default it's allowed to create up to 4096 ptys with 1024 reserve for
initial mount namespace only and the settings are controlled by host
admin.
Though this default is not enough for hosters with thousands of
containers per node. Host admin can be forced to increase it up to
NR_UNIX98_PTY_MAX = 1<<20.
By default container is restricted by pty mount_opt.max = 1024, but
admin inside container can change it via remount. As a result, one
container can consume almost all allowed ptys and allocate up to 1Gb of
unaccounted memory.
It is not enough per-se to trigger OOM on host, however anyway, it
allows to significantly exceed the assigned memcg limit and leads to
troubles on the over-committed node.
It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/5d4bca06-7d4f-a905-e518-12981ebca1b3@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The only documented function for tty_driver structure
allocation/registration was __tty_alloc_driver(). Fix highlighting in
that comment.
And add kernel-doc headers to all tty_driver_kref_put(),
tty_register_driver(), and tty_unregister_driver() -- i.e. the main
ones. More to follow later.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211126081611.11001-18-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kernel-doc is a bit strict about some formatting. So fix these:
1) When there is a tab in comments, it thinks the line is a continuation
one. So the description of the functions end up as descriptions of
the last parameter described. Remove the tabs.
2) Remove newlines before parameters description and after the comments.
This was not wrong per se, only inconsistent with the rest of the
file.
3) Add periods to the end of sentences where appropriate.
4) Add "()" to function names and "%" to constants, so that they are
properly highlighted.
By the above, this patch also unifies these docs with the other
kernel-doc's in this file.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211126081611.11001-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ops->receive_buf() may be accessed concurrently from these two
functions. If the driver flushes data to the line discipline
receive_buf() method while tiocsti() is waiting for the
ops->receive_buf() to finish its work, the data race will happen.
For example:
tty_ioctl |tty_ldisc_receive_buf
->tioctsi | ->tty_port_default_receive_buf
| ->tty_ldisc_receive_buf
->hci_uart_tty_receive | ->hci_uart_tty_receive
->h4_recv | ->h4_recv
In this case, the h4 receive buffer will be overwritten by the
latecomer, and we will lost the data.
Hence, change tioctsi() function to use the exclusive lock interface
from tty_buffer to avoid the data race.
Reported-by: syzbot+97388eb9d31b997fe1d0@syzkaller.appspotmail.com
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com>
Link: https://lore.kernel.org/r/20210823000641.2082292-1-phind.uet@gmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f9e053dcfc (tty: Serialize tty flow control changes with
flow_lock) renamed start_tty to __start_tty and stop_tty to __stop_tty
and introduced new start_tty and stop_tty. But it left kernel-doc
comments on the old locations:
tty_io.c:785: warning: expecting prototype for stop_tty(). Prototype was for __stop_tty() instead
tty_io.c:816: warning: expecting prototype for start_tty(). Prototype was for __start_tty() instead
Fix that by moving the comments to appropriate locations.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210519072153.3859-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commits a9cbbb80e3 (tty: avoid using vfs_iocb_iter_write() for
redirected console writes) and dd78b0c483 (tty: implement read_iter),
the tty_read and tty_write kernel-doc comments don't match the code:
tty_io.c:931: warning: Function parameter or member 'iocb' not described in 'tty_read'
tty_io.c:931: warning: Function parameter or member 'to' not described in 'tty_read'
tty_io.c:931: warning: Excess function parameter 'file' description in 'tty_read'
tty_io.c:931: warning: Excess function parameter 'buf' description in 'tty_read'
tty_io.c:931: warning: Excess function parameter 'count' description in 'tty_read'
tty_io.c:931: warning: Excess function parameter 'ppos' description in 'tty_read'
tty_io.c:1115: warning: Function parameter or member 'iocb' not described in 'file_tty_write'
tty_io.c:1115: warning: Function parameter or member 'from' not described in 'file_tty_write'
tty_io.c:1115: warning: expecting prototype for tty_write(). Prototype was for file_tty_write() instead
Fix them to correspond the reality, i.e. the switch from read/write to
read_iter/write_iter.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210519072153.3859-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
