tpk_write()/tpk_close() could be interrupted when holding a mutex, then
in timer handler tpk_write() may be called again trying to acquire same
mutex, lead to deadlock.
Google syzbot reported this issue with CONFIG_DEBUG_ATOMIC_SLEEP
enabled:
BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:938
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/1
1 lock held by swapper/1/0:
...
Call Trace:
<IRQ>
dump_stack+0x197/0x210
___might_sleep.cold+0x1fb/0x23e
__might_sleep+0x95/0x190
__mutex_lock+0xc5/0x13c0
mutex_lock_nested+0x16/0x20
tpk_write+0x5d/0x340
resync_tnc+0x1b6/0x320
call_timer_fn+0x1ac/0x780
run_timer_softirq+0x6c3/0x1790
__do_softirq+0x262/0x98c
irq_exit+0x19b/0x1e0
smp_apic_timer_interrupt+0x1a3/0x610
apic_timer_interrupt+0xf/0x20
</IRQ>
See link https://syzkaller.appspot.com/bug?extid=2eeef62ee31f9460ad65 for
more details.
Fix it by using spinlock in process context instead of mutex and having
interrupt disabled in critical section.
Reported-by: syzbot+2eeef62ee31f9460ad65@syzkaller.appspotmail.com
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200113034842.435-1-zhenzhong.duan@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the smems of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 5 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190111.946565886@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For some use cases it is handy to use a different printk log level than the
default (info) for the messages written to ttyprintk, so add a Kconfig
option similar to what we have for default console loglevel.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The code is a bit obscure.
Simplify it by using a single routine to flush the tpk_buffer and
emit the buffer prefixed with "[U] ".
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Constifies tty_port_operations structure in
the char driver since it is not modified
after its initialization.
Detected and found using Coccinelle.
Suggested-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Aya Mahfouz <mahfouz.saif.elyazal@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver is well written to be used as a module, just the exit call
is missing.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ttyprintk driver calls tty_unregister_driver() wrongly in the error
path of tty_register_driver(). Also, setting ttyprintk_driver to NULL
is utterly superfluous, so let's get rid of it, too.
Reported-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The TTY_PRINTK option is bool, and hence this code is either
present or absent. It will never be modular, so using
module_init as an alias for __initcall is rather misleading.
Fix this up now, so that we can relocate module_init from
init.h into module.h in the future. If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.
Note that direct use of __initcall is discouraged, vs. one
of the priority categorized subgroups. As __initcall gets
mapped onto device_initcall, our use of device_initcall
directly in this change means that the runtime impact is
zero -- it will remain at level 6 in initcall ordering.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_port_init() zeroes out the tty port, which means that we have to set the
ops pointer /after/, not before this call. Otherwise, tty_port_open will crash
when it tries to deref ops, which is now a NULL pointer.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue. So fix the drivers to fulfil this
assumption.
To be sure, the TTY buffers (and later some stuff) are gone along with
the tty_port, we have to call tty_port_destroy at tear-down places.
This is mostly where the structure containing a tty_port is freed.
This patch does exactly that -- put tty_port_destroy at those places.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We changed these from alloc_tty_driver() to tty_alloc_driver() so the
error handling needs to modified to check for IS_ERR() instead of NULL.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So now for those drivers that can use neither tty_port_install nor
tty_port_register_driver but still have tty_port available before
tty_register_driver we use newly added tty_port_link_device.
The rest of the drivers that still do not provide tty_struct <->
tty_port link will have to be converted to implement
tty->ops->install.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows drivers like ttyprintk to avoid hacks to create an
unnumbered node in /dev. It used to set TTY_DRIVER_DYNAMIC_DEV in
flags and call device_create on its own. That is incorrect, because
TTY_DRIVER_DYNAMIC_DEV may be set only if tty_register_device is
called explicitly.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After tty_register_driver is called, it is too late to initialize a
guy with which we operate in open. When a process already called
open(2) on that node, the structures may be in use uninitialized.
Move the initialization prior to tty_register_driver.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Samo Pogacnik <samo_pogacnik@t-2.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a user provides a buffer larger than a tty->write_buf chunk and
passes '\r' at the end of the buffer, we touch an out-of-bound memory.
Add a check there to prevent this.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: stable@vger.kernel.org (everything maintained past v2.6.37)
Cc: Samo Pogacnik <samo_pogacnik@t-2.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.
pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
They will need it called out explicitly in the near future due
to a module.h usage cleanup that removes its implicit presence
everywhere.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Only oddities here are a couple of drivers that bogusly called the ldisc
helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes
away.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Ttyprintk is a pseudo TTY driver, which allows users to make printk
messages, via output to ttyprintk device. It is possible to store
"console" messages inline with kernel messages for better analyses of
the boot process, for example.
Signed-off-by: Samo Pogacnik <samo_pogacnik@t-2.net>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
