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path: root/drivers/tty/n_hdlc.c
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2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-4/+4
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-28the rest of drivers/*: annotate ->poll() instancesAl Viro1-3/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-08tty: Remove redundant license textGreg Kroah-Hartman1-2/+0
Now that the SPDX tag is in all tty files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Jiri Slaby <jslaby@suse.com> Cc: James Hogan <jhogan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman1-0/+1
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-08format-security: move static strings to constKees Cook1-5/+5
While examining output from trial builds with -Wformat-security enabled, many strings were found that should be defined as "const", or as a char array instead of char pointer. This makes some static analysis easier, by producing fewer false positives. As these are all trivial changes, it seemed best to put them all in a single patch rather than chopping them up per maintainer. Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Jes Sorensen <jes@trained-monkey.org> [runner.c] Cc: Tony Lindgren <tony@atomide.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: David Airlie <airlied@linux.ie> Cc: Yisen Zhuang <yisen.zhuang@huawei.com> Cc: Salil Mehta <salil.mehta@huawei.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Jiri Slaby <jslaby@suse.com> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Mugunthan V N <mugunthanvnm@ti.com> Cc: Felipe Balbi <felipe.balbi@linux.intel.com> Cc: Jarod Wilson <jarod@redhat.com> Cc: Florian Westphal <fw@strlen.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Kejian Yan <yankejian@huawei.com> Cc: Daode Huang <huangdaode@hisilicon.com> Cc: Qianqian Xie <xieqianqian@huawei.com> Cc: Philippe Reynes <tremyfr@gmail.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Christian Gromm <christian.gromm@microchip.com> Cc: Andrey Shvetsov <andrey.shvetsov@k2l.de> Cc: Jason Litzinger <jlitzingerdev@gmail.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-07tty: n_hdlc: get rid of racy n_hdlc.tbufAlexander Popov1-63/+69
Currently N_HDLC line discipline uses a self-made singly linked list for data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after an error. The commit be10eb7589337e5defbe214dae038a53dd21add8 ("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf. After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put one data buffer to tx_free_buf_list twice. That causes double free in n_hdlc_release(). Let's use standard kernel linked list and get rid of n_hdlc.tbuf: in case of tx error put current data buffer after the head of tx_buf_list. Signed-off-by: Alexander Popov <alex.popov@linux.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-27lib/vsprintf.c: remove %Z supportAlexey Dobriyan1-1/+1
Now that %z is standartised in C99 there is no reason to support %Z. Unlike %L it doesn't even make format strings smaller. Use BUILD_BUG_ON in a couple ATM drivers. In case anyone didn't notice lib/vsprintf.o is about half of SLUB which is in my opinion is quite an achievement. Hopefully this patch inspires someone else to trim vsprintf.c more. Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-01Fix OpenSSH pty regression on closeBrian Bloniarz1-2/+2
OpenSSH expects the (non-blocking) read() of pty master to return EAGAIN only if it has received all of the slave-side output after it has received SIGCHLD. This used to work on pre-3.12 kernels. This fix effectively forces non-blocking read() and poll() to block for parallel i/o to complete for all ttys. It also unwinds these changes: 1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12 tty: Fix pty master read() after slave closes 2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73 pty, n_tty: Simplify input processing on final close 3) 1a48632ffed61352a7810ce089dc5a8bcd505a60 pty: Fix input race when closing Inspired by analysis and patch from Marc Aurele La France <tsi@tuyoix.net> Reported-by: Volth <openssh@volth.com> Reported-by: Marc Aurele La France <tsi@tuyoix.net> BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52 BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492 Signed-off-by: Brian Bloniarz <brian.bloniarz@gmail.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06TTY: n_hdlc, fix lockdep false positiveJiri Slaby1-15/+4
The class of 4 n_hdls buf locks is the same because a single function n_hdlc_buf_list_init is used to init all the locks. But since flush_tx_queue takes n_hdlc->tx_buf_list.spinlock and then calls n_hdlc_buf_put which takes n_hdlc->tx_free_buf_list.spinlock, lockdep emits a warning: ============================================= [ INFO: possible recursive locking detected ] 4.3.0-25.g91e30a7-default #1 Not tainted --------------------------------------------- a.out/1248 is trying to acquire lock: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc] but task is already holding lock: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&list->spinlock)->rlock); lock(&(&list->spinlock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by a.out/1248: #0: (&tty->ldisc_sem){++++++}, at: [<ffffffff814c9eb0>] tty_ldisc_ref_wait+0x20/0x50 #1: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc] ... Call Trace: ... [<ffffffff81738fd0>] _raw_spin_lock_irqsave+0x50/0x70 [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc] [<ffffffffa01fdc24>] n_hdlc_tty_ioctl+0x144/0x1d0 [n_hdlc] [<ffffffff814c25c1>] tty_ioctl+0x3f1/0xe40 ... Fix it by initializing the spin_locks separately. This removes also reduntand memset of a freshly kzallocated space. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10pty: Fix input race when closingPeter Hurley1-2/+2
A read() from a pty master may mistakenly indicate EOF (errno == -EIO) after the pty slave has closed, even though input data remains to be read. For example, pty slave | input worker | pty master | | | | n_tty_read() pty_write() | | input avail? no add data | | sleep schedule worker --->| | . |---> flush_to_ldisc() | . pty_close() | fill read buffer | . wait for worker | wakeup reader --->| . | read buffer full? |---> input avail ? yes |<--- yes - exit worker | copy 4096 bytes to user TTY_OTHER_CLOSED <---| |<--- kick worker | | **** New read() before worker starts **** | | n_tty_read() | | input avail? no | | TTY_OTHER_CLOSED? yes | | return -EIO Several conditions are required to trigger this race: 1. the ldisc read buffer must become full so the input worker exits 2. the read() count parameter must be >= 4096 so the ldisc read buffer is empty 3. the subsequent read() occurs before the kicked worker has processed more input However, the underlying cause of the race is that data is pipelined, while tty state is not; ie., data already written by the pty slave end is not yet visible to the pty master end, but state changes by the pty slave end are visible to the pty master end immediately. Pipeline the TTY_OTHER_CLOSED state through input worker to the reader. 1. Introduce TTY_OTHER_DONE which is set by the input worker when TTY_OTHER_CLOSED is set and either the input buffers are flushed or input processing has completed. Readers/polls are woken when TTY_OTHER_DONE is set. 2. Reader/poll checks TTY_OTHER_DONE instead of TTY_OTHER_CLOSED. 3. A new input worker is started from pty_close() after setting TTY_OTHER_CLOSED, which ensures the TTY_OTHER_DONE state will be set if the last input worker is already finished (or just about to exit). Remove tty_flush_to_ldisc(); no in-tree callers. Fixes: 52bce7f8d4fc ("pty, n_tty: Simplify input processing on final close") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96311 BugLink: http://bugs.launchpad.net/bugs/1429756 Cc: <stable@vger.kernel.org> # 3.19+ Reported-by: Andy Whitcroft <apw@canonical.com> Reported-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28drivers/tty/n_hdlc.c: replace kmalloc/memset by kzallocFabian Frederick1-3/+1
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27tty: n_hdlc: Drop redundant error messageJean Delvare1-4/+0
On initialization failure, an error message is already printed with level KERN_ERR, no need to print another one with level KERN_INFO. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells1-1/+0
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2011-11-30tty: n_hdlc not atomic use tty->flags.Ilya Zykov1-3/+3
N_HDLC can spoil tty->flags because use not atomic operations on tty->flags. I use n_hdlc line discipline and it happens. Signed-off-by: Ilya Zykov <ilya@ilyx.ru> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-04Revert "tty: make receive_buf() return the amout of bytes received"Linus Torvalds1-10/+8
This reverts commit b1c43f82c5aa265442f82dba31ce985ebb7aa71c. It was broken in so many ways, and results in random odd pty issues. It re-introduced the buggy schedule_work() in flush_to_ldisc() that can cause endless work-loops (see commit a5660b41af6a: "tty: fix endless work loop when the buffer fills up"). It also used an "unsigned int" return value fo the ->receive_buf() function, but then made multiple functions return a negative error code, and didn't actually check for the error in the caller. And it didn't actually work at all. BenH bisected down odd tty behavior to it: "It looks like the patch is causing some major malfunctions of the X server for me, possibly related to PTYs. For example, cat'ing a large file in a gnome terminal hangs the kernel for -minutes- in a loop of what looks like flush_to_ldisc/workqueue code, (some ftrace data in the quoted bits further down). ... Some more data: It -looks- like what happens is that the flush_to_ldisc work queue entry constantly re-queues itself (because the PTY is full ?) and the workqueue thread will basically loop forver calling it without ever scheduling, thus starving the consumer process that could have emptied the PTY." which is pretty much exactly the problem we fixed in a5660b41af6a. Milton Miller pointed out the 'unsigned int' issue. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reported-by: Milton Miller <miltonm@bga.com> Cc: Stefan Bigler <stefan.bigler@keymile.com> Cc: Toby Gray <toby.gray@realvnc.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-22tty: make receive_buf() return the amout of bytes receivedFelipe Balbi1-8/+10
it makes it simpler to keep track of the amount of bytes received and simplifies how flush_to_ldisc counts the remaining bytes. It also fixes a bug of lost bytes on n_tty when flushing too many bytes via the USB serial gadget driver. Tested-by: Stefan Bigler <stefan.bigler@keymile.com> Tested-by: Toby Gray <toby.gray@realvnc.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-02drivers: remove extraneous includes of smp_lock.hArnd Bergmann1-1/+0
These were missed the last time I cleaned this up globally, because of code moving around or new code getting merged. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2011-01-22n_hdlc: fix read and write lockingPaul Fulghum1-45/+45
Fix locking in read and write code of n_hdlc line discipline. 2.6.36 replaced lock_kernel() with tty_lock(). The tty mutex is not dropped automatically when the thread sleeps like the BKL. This results in a blocked read or write holding the tty mutex and stalling operations by other devices that use the tty mutex. A review of n_hdlc read and write code shows: 1. neither BKL or tty mutex are required for correct operation 2. read can block while read data is available if data is posted between availability check and call to interruptible_sleep_on() 3. write does not set process state to TASK_INTERRUPTIBLE on each pass through the processing loop which can cause unneeded scheduling of the thread The unnecessary tty mutex references have been removed. Read changed to use same code as n_tty read for completing reads and blocking. Write corrected to set process state to TASK_INTERRUPTIBLE on each pass through processing loop. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-05TTY: create drivers/tty and move the tty core files thereGreg Kroah-Hartman1-0/+1007
The tty code should be in its own subdirectory and not in the char driver with all of the cruft that is currently there. Based on work done by Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>