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path: root/drivers/char/ttyprintk.c
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2020-07-10ttyprintk: remove redundant initialization of variable retColin Ian King1-1/+1
The variable ret is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20200611153108.927614-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14ttyprintk: fix a potential deadlock in interrupt context issueZhenzhong Duan1-6/+9
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>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 402Thomas Gleixner1-4/+1
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>
2018-11-09ttyprintk: make the printk log level configurablePeter Korsgaard1-1/+3
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>
2016-09-13ttyprintk: Neaten and simplify printingJoe Perches1-38/+31
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>
2016-02-06char: constify tty_port_operations structsAya Mahfouz1-1/+1
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>
2014-04-16ttyprintk: Allow built as a moduleTakashi Iwai1-1/+12
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>
2014-04-16ttyprintk: Fix wrong tty_unregister_driver() call in the error pathTakashi Iwai1-2/+0
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>
2014-01-13drivers/char: don't use module_init in non-modular ttyprintk.cPaul Gortmaker1-1/+1
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>
2013-05-21ttyprintk: Fix NULL pointer deref by setting tty_port ops after initializing ↵Darrick J. Wong1-1/+1
port 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>
2012-11-15TTY: call tty_port_destroy in the rest of driversJiri Slaby1-1/+3
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>
2012-08-16TTY: tty_alloc_driver() returns error pointersDan Carpenter1-2/+2
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>
2012-08-13TTY: use tty_port_link_deviceJiri Slaby1-0/+1
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>
2012-08-13TTY: add support for unnumbered device nodesJiri Slaby1-13/+4
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>
2012-08-10TTY: ttyprintk, initialize tty_port earlierJiri Slaby1-4/+4
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>
2012-08-10TTY: ttyprintk, don't touch behind tty->write_bufJiri Slaby1-1/+1
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>
2012-08-10TTY: ttyprintk, unregister tty driver on failureJiri Slaby1-0/+1
When the tty_printk driver fails to create a node in sysfs, the system crashes. It is because the driver registers a tty driver and frees it without deregistering it first. The fix is easy: add a call to tty_unregister_driver to the fail path. This is very unlikely to happen in usual environment => no need for stable. The crash occurs at some place where we iterate over tty drivers first. It may look like this: BUG: unable to handle kernel paging request at ffffffffffffff84 IP: [<ffffffff81278d56>] tty_open+0xd6/0x650 PGD 1a0d067 PUD 1a0e067 PMD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: CPU 0 Pid: 1183, comm: boot.localnet Tainted: G W 3.5.0-rc7-next-20120716+ #369 Bochs Bochs RIP: 0010:[<ffffffff81278d56>] [<ffffffff81278d56>] tty_open+0xd6/0x650 RSP: 0018:ffff8800162b3b98 EFLAGS: 00010207 RAX: 0000000000000000 RBX: ffff880016ba6200 RCX: 0000000000002208 RDX: 0000000000000000 RSI: 00000000000000d0 RDI: ffffffff81a35080 RBP: ffff8800162b3c08 R08: ffffffff81276f42 R09: 0000000000400040 R10: ffff8800161dc005 R11: ffff8800188ee048 R12: 0000000000000000 R13: ffffffffffffff58 R14: 0000000000400040 R15: 0000000000008000 FS: 00007f3684abd700(0000) GS:ffff880018e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffff84 CR3: 000000001503e000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process boot.localnet (pid: 1183, threadinfo ffff8800162b2000, task ffff8800188c5880) Stack: ffff8800162b3c08 ffffffff81363d63 ffffffff81a62940 ffff8800189b4e88 ffff8800188c5880 ffffffff81123180 0000000000000000 ffffffff18b20600 0000000000000000 ffff8800189b4e88 ffff880016ba6200 ffff880018b20600 Call Trace: [<ffffffff81363d63>] ? kobj_lookup+0x103/0x160 [<ffffffff81123180>] ? mount_fs+0x110/0x110 [<ffffffff81123a9c>] chrdev_open+0x9c/0x1a0 [<ffffffff81123a00>] ? cdev_put+0x30/0x30 [<ffffffff8111de76>] do_dentry_open.isra.19+0x1e6/0x270 [<ffffffff8111df65>] finish_open+0x65/0xa0 [<ffffffff8112dc9e>] do_last.isra.52+0x26e/0xd80 [<ffffffff8112b163>] ? inode_permission+0x13/0x50 [<ffffffff8112b203>] ? link_path_walk+0x63/0x940 [<ffffffff8112e85b>] path_openat+0xab/0x3d0 [<ffffffff8112ef5d>] do_filp_open+0x3d/0xa0 [<ffffffff8113ba72>] ? alloc_fd+0xd2/0x120 [<ffffffff8111eee3>] do_sys_open+0xf3/0x1d0 [<ffffffff8111efdc>] sys_open+0x1c/0x20 [<ffffffff815b5fe2>] system_call_fastpath+0x16/0x1b 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>
2012-03-08TTY: remove re-assignments to tty_driver membersJiri Slaby1-2/+0
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>
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * '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
2011-11-02um: switch to use of drivers/KconfigAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
2011-10-31drivers/char: Add export.h for EXPORT_SYMBOL/THIS_MODULE as requiredPaul Gortmaker1-0/+1
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>
2011-02-17tty: now phase out the ioctl file pointer for goodAlan Cox1-1/+1
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>
2010-10-22add ttyprintk driverSamo Pogacnik1-0/+225
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>
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