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path: root/drivers/tty/tty_io.c
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2021-02-20Merge tag 'tty-5.12-rc1' of ↵Linus Torvalds
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/serial driver changes for 5.12-rc1. Nothing huge, just lots of good cleanups and additions: - n_tty line discipline cleanups - vt core cleanups and reworks to make the code more "modern" - stm32 driver additions - tty led support added to the tty core and led layer - minor serial driver fixups and additions All of these have been in linux-next for a while with no reported issues" * tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (54 commits) serial: core: Remove BUG_ON(in_interrupt()) check vt_ioctl: Remove in_interrupt() check dt-bindings: serial: imx: Switch to my personal address vt: keyboard, use new API for keyboard_tasklet serial: stm32: improve platform_get_irq condition handling in init_port serial: ifx6x60: Remove driver for deprecated platform tty: fix up iterate_tty_read() EOVERFLOW handling tty: fix up hung_up_tty_read() conversion tty: fix up hung_up_tty_write() conversion tty: teach the n_tty ICANON case about the new "cookie continuations" too tty: teach n_tty line discipline about the new "cookie continuations" tty: clean up legacy leftovers from n_tty line discipline tty: implement read_iter tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer serial: remove sirf prima/atlas driver serial: mxs-auart: Remove <asm/cacheflush.h> serial: mxs-auart: Remove serial_mxs_probe_dt() serial: fsl_lpuart: Use of_device_get_match_data() dt-bindings: serial: renesas,hscif: Add r8a779a0 support tty: serial: Drop unused efm32 serial driver ...
2021-02-20tty: protect tty_write from odd low-level tty disciplinesLinus Torvalds
Al root-caused a new warning from syzbot to the ttyprintk tty driver returning a write count larger than the data the tty layer actually gave it. Which confused the tty write code mightily, and with the new iov_iter based code, caused a WARNING in iov_iter_revert(). syzbot correctly bisected the source of the new warning to commit 9bb48c82aced ("tty: implement write_iter"), but the oddity goes back much further, it just didn't get caught by anything before. Reported-by: syzbot+3d2c27c2b7dc2a94814d@syzkaller.appspotmail.com Fixes: 9bb48c82aced ("tty: implement write_iter") Debugged-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-29tty: avoid using vfs_iocb_iter_write() for redirected console writesLinus Torvalds
It turns out that the vfs_iocb_iter_{read,write}() functions are entirely broken, and don't actually use the passed-in file pointer for IO - only for the preparatory work (permission checking and for the write_iter function lookup). That worked fine for overlayfs, which always builds the new iocb with the same file pointer that it passes in, but in the general case it ends up doing nonsensical things (and could cause an iterator call that doesn't even match the passed-in file pointer). This subtly broke the tty conversion to write_iter in commit 9bb48c82aced ("tty: implement write_iter"), because the console redirection didn't actually end up redirecting anything, since the passed-in file pointer was basically ignored, and the actual write was done with the original non-redirected console tty after all. The main visible effect of this is that the console messages were no longer logged to /var/log/boot.log during graphical boot. Fix the issue by simply not using the vfs write "helper" function at all, and just redirecting the write entirely internally to the tty layer. Do the target writability permission checks when actually registering the target tty with TIOCCONS instead of at write time. Fixes: 9bb48c82aced ("tty: implement write_iter") Reported-and-tested-by: Hans de Goede <hdegoede@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-25Commit 9bb48c82aced ("tty: implement write_iter") converted the ttySami Tolvanen
layer to use write_iter. Fix the redirected_tty_write declaration also in n_tty and change the comparisons to use write_iter instead of write. [ Also moved the declaration of redirected_tty_write() to the proper location in a header file. The reason for the bug was the bogus extern declaration in n_tty.c silently not matching the changed definition in tty_io.c, and because it wasn't in a shared header file, there was no cross-checking of the declaration. Sami noticed because Clang's Control Flow Integrity checking ended up incidentally noticing the inconsistent declaration. - Linus ] Fixes: 9bb48c82aced ("tty: implement write_iter") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-22tty: fix up hung_up_tty_write() conversionLinus Torvalds
In commit "tty: implement write_iter", I left the write_iter conversion of the hung up tty case alone, because I incorrectly thought it didn't matter. Jiri showed me the errors of my ways, and pointed out the problems with that incomplete conversion. Fix it all up. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22tty: fix up iterate_tty_read() EOVERFLOW handlingLinus Torvalds
When I converted the tty_ldisc_ops 'read()' function to take a kernel pointer, I was a bit too aggressive about the ldisc returning EOVERFLOW. Yes, we want to have EOVERFLOW override any partially read data (because the whole point is that the buffer was too small for the whole packet, and we don't want to see partial packets), but it shouldn't override a previous EFAULT. And in fact, it really is just EOVERFLOW that is special and should throw away any partially read data, not "any error". Admittedly EOVERFLOW is currently the only one that can happen for a continuation read - and if the first read iteration returns an error we won't have this issue. So this is more of a technicality, but let's just make the intent very explicit, and re-organize the error handling a bit so that this is all clearer. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22tty: fix up hung_up_tty_read() conversionLinus Torvalds
In commit "tty: implement read_iter", I left the read_iter conversion of the hung up tty case alone, because I incorrectly thought it didn't matter. Jiri showed me the errors of my ways, and pointed out the problems with that incomplete conversion. Fix it all up. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22tty: fix up hung_up_tty_write() conversionLinus Torvalds
In commit "tty: implement write_iter", I left the write_iter conversion of the hung up tty case alone, because I incorrectly thought it didn't matter. Jiri showed me the errors of my ways, and pointed out the problems with that incomplete conversion. Fix it all up. Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-21Merge branch 'tty-splice' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into tty-next Fixes both the "splice/sendfile to a tty" and "splice/sendfile from a tty" regression from 5.10. * 'tty-splice' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux: tty: teach the n_tty ICANON case about the new "cookie continuations" too tty: teach n_tty line discipline about the new "cookie continuations" tty: clean up legacy leftovers from n_tty line discipline tty: implement read_iter tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer tty: implement write_iter
2021-01-21Merge 9bb48c82aced ("tty: implement write_iter") into tty-linusGreg Kroah-Hartman
We want the single "splice/sendfile to a tty" regression fix into tty-linus so it can get into 5.11-final, while the larger patch series fixing "splice/sendfile from a tty" should wait for 5.12-rc1 so that we get more testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-20tty: implement write_iterLinus Torvalds
This makes the tty layer use the .write_iter() function instead of the traditional .write() functionality. That allows writev(), but more importantly also makes it possible to enable .splice_write() for ttys, reinstating the "splice to tty" functionality that was lost in commit 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops"). Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") Reported-by: Oliver Giles <ohw.giles@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20tty: implement read_iterLinus Torvalds
Now that the ldisc read() function takes kernel pointers, it's fairly straightforward to make the tty file operations use .read_iter() instead of .read(). That automatically gives us vread() and friends, and also makes it possible to do .splice_read() on ttys again. Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") Reported-by: Oliver Giles <ohw.giles@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20tty: convert tty_ldisc_ops 'read()' function to take a kernel pointerLinus Torvalds
The tty line discipline .read() function was passed the final user pointer destination as an argument, which doesn't match the 'write()' function, and makes it very inconvenient to do a splice method for ttys. This is a conversion to use a kernel buffer instead. NOTE! It does this by passing the tty line discipline ->read() function an additional "cookie" to fill in, and an offset into the cookie data. The line discipline can fill in the cookie data with its own private information, and then the reader will repeat the read until either the cookie is cleared or it runs out of data. The only real user of this is N_HDLC, which can use this to handle big packets, even if the kernel buffer is smaller than the whole packet. Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-07drivers:tty:pty: Fix a race causing data loss on closeCorey Minyard
Remove the tty_vhangup() from the pty code and just release the redirect. The tty_vhangup() results in data loss and data out of order issues. If you write to a pty master an immediately close the pty master, the receiver might get a chunk of data dropped, but then receive some later data. That's obviously something rather unexpected for a user. It certainly confused my test program. It turns out that tty_vhangup() on the slave pty gets called from pty_close(), and that causes the data on the slave side to be flushed, but due to races more data can be copied into the slave side's buffer after that. Consider the following sequence: thread1 thread2 thread3 ------- ------- ------- | |-write data into buffer, | | n_tty buffer is filled | | along with other buffers | |-pty_close(master) | |--tty_vhangup(slave) | |---tty_ldisc_hangup() | |----n_tty_flush_buffer() | |-----reset_buffer_flags() |-n_tty_read() | |--up_read(&tty->termios_rwsem); | |------down_read(&tty->termios_rwsem) | |------clear n_tty buffer contents | |------up_read(&tty->termios_rwsem) |--tty_buffer_flush_work() | |--schedules work calling | | flush_to_ldisc() | | |-flush_to_ldisc() | |--receive_buf() | |---tty_port_default_receive_buf() | |----tty_ldisc_receive_buf() | |-----n_tty_receive_buf2() | |------n_tty_receive_buf_common() | |-------down_read(&tty->termios_rwsem) | |-------__receive_buf() | | copies data into n_tty buffer | |-------up_read(&tty->termios_rwsem) |--down_read(&tty->termios_rwsem) |--copy buffer data to user >From this sequence, you can see that thread2 writes to the buffer then only clears the part of the buffer in n_tty. The n_tty receive buffer code then copies more data into the n_tty buffer. But part of the vhangup, releasing the redirect, is still required to avoid issues with consoles running on pty slaves. So do that. As far as I can tell, that is all that should be required. Signed-off-by: Corey Minyard <cminyard@mvista.com> Link: https://lore.kernel.org/r/20201124004902.1398477-3-minyard@acm.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07tty: Export redirect releaseCorey Minyard
This will be required by the pty code when it removes tty_vhangup() on master close. Signed-off-by: Corey Minyard <cminyard@mvista.com> Link: https://lore.kernel.org/r/20201124004902.1398477-2-minyard@acm.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-28tty: new helper function tty_get_icount()Uwe Kleine-König
For a given struct tty_struct this yields the corresponding statistics about sent and received characters (and some more) which is needed to implement an LED trigger for tty devices. The new function is then used to simplify tty_tiocgicount(). Reviewed-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20201218104246.591315-3-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-28tty: rename tty_kopen() and add new function tty_kopen_shared()Uwe Kleine-König
Introduce a new function tty_kopen_shared() that yields a struct tty_struct. The semantic difference to tty_kopen() is that the tty is expected to be used already. So rename tty_kopen() to tty_kopen_exclusive() for clearness, adapt the single user and put the common code in a new static helper function. tty_kopen_shared is to be used to implement an LED trigger for tty devices in one of the next patches. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20201218104246.591315-2-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-07Merge 5.10-rc7 into tty-nextGreg Kroah-Hartman
We want the tty fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-04tty: Fix ->session lockingJann Horn
Currently, locking of ->session is very inconsistent; most places protect it using the legacy tty mutex, but disassociate_ctty(), __do_SAK(), tiocspgrp() and tiocgsid() don't. Two of the writers hold the ctrl_lock (because they already need it for ->pgrp), but __proc_set_tty() doesn't do that yet. On a PREEMPT=y system, an unprivileged user can theoretically abuse this broken locking to read 4 bytes of freed memory via TIOCGSID if tiocgsid() is preempted long enough at the right point. (Other things might also go wrong, especially if root-only ioctls are involved; I'm not sure about that.) Change the locking on ->session such that: - tty_lock() is held by all writers: By making disassociate_ctty() hold it. This should be fine because the same lock can already be taken through the call to tty_vhangup_session(). The tricky part is that we need to shorten the area covered by siglock to be able to take tty_lock() without ugly retry logic; as far as I can tell, this should be fine, since nothing in the signal_struct is touched in the `if (tty)` branch. - ctrl_lock is held by all writers: By changing __proc_set_tty() to hold the lock a little longer. - All readers that aren't holding tty_lock() hold ctrl_lock: By adding locking to tiocgsid() and __do_SAK(), and expanding the area covered by ctrl_lock in tiocspgrp(). Cc: stable@kernel.org Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-09Merge 5.10-rc3 into tty-nextGreg Kroah-Hartman
We need the TTY/vt/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06tty: fix crash in release_tty if tty->port is not setMatthias Reichl
Commit 2ae0b31e0face ("tty: don't crash in tty_init_dev when missing tty_port") didn't fully prevent the crash as the cleanup path in tty_init_dev() calls release_tty() which dereferences tty->port without checking it for non-null. Add tty->port checks to release_tty to avoid the kernel crash. Fixes: 2ae0b31e0face ("tty: don't crash in tty_init_dev when missing tty_port") Signed-off-by: Matthias Reichl <hias@horus.com> Link: https://lore.kernel.org/r/20201105123432.4448-1-hias@horus.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06tty: tty_io: Fix some kernel-doc issuesLee Jones
Demote non-conformant headers and supply some missing descriptions. Fixes the following W=1 kernel build warning(s): drivers/tty/tty_io.c:218: warning: Function parameter or member 'file' not described in 'tty_free_file' drivers/tty/tty_io.c:566: warning: Function parameter or member 'exit_session' not described in '__tty_hangup' drivers/tty/tty_io.c:1077: warning: Function parameter or member 'tty' not described in 'tty_send_xchar' drivers/tty/tty_io.c:1077: warning: Function parameter or member 'ch' not described in 'tty_send_xchar' drivers/tty/tty_io.c:1155: warning: Function parameter or member 'file' not described in 'tty_driver_lookup_tty' drivers/tty/tty_io.c:1508: warning: Function parameter or member 'tty' not described in 'release_tty' drivers/tty/tty_io.c:1508: warning: Function parameter or member 'idx' not described in 'release_tty' drivers/tty/tty_io.c:2973: warning: Function parameter or member 'driver' not described in 'alloc_tty_struct' drivers/tty/tty_io.c:2973: warning: Function parameter or member 'idx' not described in 'alloc_tty_struct' Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Nick Holloway <alfie@dcs.warwick.ac.uk> Cc: -- <julian@uhunix.uhcc.hawaii.edu> Cc: Marko Kohtala <Marko.Kohtala@hut.fi> Cc: Bill Hawes <whawes@star.net> Cc: "C. Scott Ananian" <cananian@alumni.princeton.edu> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Andrew Morton <andrewm@uow.edu.eu> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20201104193549.4026187-13-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06tty: tty_io: Move 'tty_sysctl_init's prototype to shared spaceLee Jones
Fixes the following W=1 kernel build warning(s): drivers/tty/tty_ldisc.c:883:6: warning: no previous prototype for ‘tty_sysctl_init’ [-Wmissing-prototypes] 883 | void tty_sysctl_init(void) | ^~~~~~~~~~~~~~~ Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Nick Holloway <alfie@dcs.warwick.ac.uk> Cc: -- <julian@uhunix.uhcc.hawaii.edu> Cc: Marko Kohtala <Marko.Kohtala@hut.fi> Cc: Bill Hawes <whawes@star.net> Cc: "C. Scott Ananian" <cananian@alumni.princeton.edu> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Andrew Morton <andrewm@uow.edu.eu> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20201104193549.4026187-5-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18tty: fix kernel-docJiri Slaby
With W=1, the kernel-doc checker complains quite a lot in the tty layer. Over the time, many documented parameters were renamed, removed or switched from tty to tty_port and similar. Some were mistyped in the doc too. So fix all these in the tty core. (But do not add the missing ones which the checker complains about too. Not now.) The rest in the tty layer will follow in the next patches. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085655.12071-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29tty: Use the preferred form for passing the size of a structure typeGustavo A. R. Silva
Use the preferred form for passing the size of a structure type. The alternative form where the structure type is spelled out hurts readability and introduces an opportunity for a bug when the object type is changed but the corresponding object identifier to which the sizeof operator is applied is not. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Acked-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/b04dd8cdd67bd6ffde3fd12940aeef35fdb824a6.1595543280.git.gustavoars@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29tty: Fix identation issues in struct serial_struct32Gustavo A. R. Silva
Fix the following checkpatch.pl warnings together with all the identation issues in struct serial_struct32: ERROR: code indent should use tabs where possible + char reserved_char;$ WARNING: please, no spaces at the start of a line + char reserved_char;$ ERROR: code indent should use tabs where possible + compat_int_t reserved;$ WARNING: please, no spaces at the start of a line + compat_int_t reserved;$ Acked-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/77576843397aeab0af8aa0423a9768f3ca8dedfb.1595543280.git.gustavoars@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29tty: Avoid the use of one-element arraysGustavo A. R. Silva
One-element arrays are being deprecated[1]. Replace the one-element arrays with simple value types 'char reserved_char' and 'compat_int_t reserved'[2], once it seems these are just placeholders for alignment. [1] https://github.com/KSPP/linux/issues/79 [2] https://github.com/KSPP/linux/issues/86 Tested-by: kernel test robot <lkp@intel.com> Link: https://github.com/GustavoARSilva/linux-hardening/blob/master/cii/0-day/tty-20200716.md Acked-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/f49bf0e27eaac396c96d21392c8c284f9f5ef52a.1595543280.git.gustavoars@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18tty: fix compat TIOCGSERIAL checking wrong function ptrEric Biggers
Commit 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start checking for the presence of the ->set_serial function pointer rather than ->get_serial. This appears to be a copy-and-paste error, since ->get_serial is the function pointer that is called as well as the pointer that is checked by the non-compat version of TIOCGSERIAL. Fix this by checking the correct function pointer. Fixes: 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()") Cc: <stable@vger.kernel.org> # v4.20+ Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200224182044.234553-3-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18tty: fix compat TIOCGSERIAL leaking uninitialized memoryEric Biggers
Commit 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start copying a whole 'serial_struct32' to userspace rather than individual fields, but failed to initialize all padding and fields -- namely the hole after the 'iomem_reg_shift' field, and the 'reserved' field. Fix this by initializing the struct to zero. [v2: use sizeof, and convert the adjacent line for consistency.] Reported-by: syzbot+8da9175e28eadcb203ce@syzkaller.appspotmail.com Fixes: 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()") Cc: <stable@vger.kernel.org> # v4.20+ Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200224182044.234553-2-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18tty: drop outdated comments about release_tty() lockingEric Biggers
The current version of the TTY code unlocks the tty_struct(s) before release_tty() rather than after. Moreover, tty_unlock_pair() no longer exists. Thus, remove the outdated comments regarding tty_unlock_pair(). Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200224073359.292795-1-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17tty: drop useless variable initialisation in tty_kopen()Uwe Kleine-König
The driver variable is assigned to unconditionally and not used before. So there is no need to explicitly initialize it at the start of tty_kopen(). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20191217075040.8020-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-03Merge tag 'tty-5.5-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial updates from Greg KH: "Here is the "big" tty and serial driver patches for 5.5-rc1. It's a bit later in the merge window than normal as I wanted to make sure some last-minute patches applied to it were all sane. They seem to be :) There's a lot of little stuff in here, for the tty core, and for lots of serial drivers: - reverts of uartlite serial driver patches that were wrong - msm-serial driver fixes - serial core updates and fixes - tty core fixes - serial driver dma mapping api changes - lots of other tiny fixes and updates for serial drivers All of these have been in linux-next for a while with no reported issues" * tag 'tty-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (58 commits) Revert "serial/8250: Add support for NI-Serial PXI/PXIe+485 devices" vcs: prevent write access to vcsu devices tty: vt: keyboard: reject invalid keycodes tty: don't crash in tty_init_dev when missing tty_port serial: stm32: fix clearing interrupt error flags tty: Fix Kconfig indentation, continued serial: serial_core: Perform NULL checks for break_ctl ops tty: remove unused argument from tty_open_by_driver() tty: Fix Kconfig indentation {tty: serial, nand: onenand}: samsung: rename to fix build warning serial: ifx6x60: add missed pm_runtime_disable serial: pl011: Fix DMA ->flush_buffer() Revert "serial-uartlite: Move the uart register" Revert "serial-uartlite: Add get serial id if not provided" Revert "serial-uartlite: Do not use static struct uart_driver out of probe()" Revert "serial-uartlite: Add runtime support" Revert "serial-uartlite: Change logic how console_port is setup" Revert "serial-uartlite: Use allocated structure instead of static ones" tty: serial: msm_serial: Use dma_request_chan() directly for channel request tty: serial: tegra: Use dma_request_chan() directly for channel request ...
2019-11-22tty: don't crash in tty_init_dev when missing tty_portJiri Slaby
We currently warn the user when tty->port is not set in tty_init_dev yet. The warning says that the kernel will crash later. And it really will only few lines below at: tty->port->itty = tty; So be nice and avoid the crash -- return an error instead. And update the warning. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lore.kernel.org/r/20191122101721.7222-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-20tty: remove unused argument from tty_open_by_driver()Sudip Mukherjee
The argument 'inode' passed to tty_open_by_driver() was not being used. Remove the extra argument. Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lore.kernel.org/r/20191120151709.14148-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-23tty: handle compat PPP ioctlsArnd Bergmann
Multiple tty devices are have tty devices that handle the PPPIOCGUNIT and PPPIOCGCHAN ioctls. To avoid adding a compat_ioctl handler to each of those, add it directly in tty_compat_ioctl so we can remove the calls from fs/compat_ioctl.c. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-23compat_ioctl: move SIOCOUTQ out of compat_ioctl.cArnd Bergmann
All users of this call are in socket or tty code, so handling it there means we can avoid the table entry in fs/compat_ioctl.c. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Eric Dumazet <edumazet@google.com> Cc: netdev@vger.kernel.org Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-07-30drivers: Introduce device lookup variants by device typeSuzuki K Poulose
Add a helper to match a device by its type and provide wrappers for {bus/class/driver}_find_device() APIs. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-usb@vger.kernel.org Cc: Oliver Neukum <oneukum@suse.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tomas Winkler <tomas.winkler@intel.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20190723221838.12024-5-suzuki.poulose@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24tty: tty_io: fix driver refcount imbalance on error pathLin Yi
tty_lookup_driver take a reference to the struct tty_driver, but forget to release it on the error path, lead to a memory leak. add a tty_driver_kref_put before error return. Signed-off-by: Lin Yi <teroincn@163.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25tty: update obsolete termios commentJohan Hovold
Update an obsolete comment referring to the termios_locked structure which was removed over a decade ago by commit fe6e29fdb1a7 ("tty: simplify ktermios allocation"). While at it, fix the "Thus" typo. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-29Revert "tty: pty: Fix race condition between release_one_tty and pty_write"Greg Kroah-Hartman
This reverts commit b9ca5f8560af244489b4a1bc1ae88b341f24bc95 as 0-day shows it has a circular locking dependency. Fixes: b9ca5f8560af ("tty: pty: Fix race condition between release_one_tty and pty_write") Reported-by: kernel test robot <lkp@intel.com> Cc: Sahara <keun-o.park@darkmatter.ae> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-28tty: pty: Fix race condition between release_one_tty and pty_writeSahara
Especially when a linked tty is used such as pty, the linked tty port's buf works have not been cancelled while master tty port's buf work has been cancelled. Since release_one_tty and flush_to_ldisc run in workqueue threads separately, when pty_cleanup happens and link tty port is freed, flush_to_ldisc tries to access freed port and port->itty, eventually it causes a panic. This patch utilizes the magic value with holding the tty_mutex to check if the tty->link is valid. Fixes: 2b022ab7542d ("pty: cancel pty slave port buf's work in tty_release") Signed-off-by: Sahara <keun-o.park@darkmatter.ae> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-30tty: ldisc: add sysctl to prevent autoloading of ldiscsGreg Kroah-Hartman
By default, the kernel will automatically load the module of any line dicipline that is asked for. As this sometimes isn't the safest thing to do, provide a sysctl to disable this feature. By default, we set this to 'y' as that is the historical way that Linux has worked, and we do not want to break working systems. But in the future, perhaps this can default to 'n' to prevent this functionality. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-21tty: Handle problem if line discipline does not have receive_bufGreg Kroah-Hartman
Some tty line disciplines do not have a receive buf callback, so properly check for that before calling it. If they do not have this callback, just eat the character quietly, as we can't fail this call. Reported-by: Jann Horn <jannh@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-11tty: Don't hold ldisc lock in tty_reopen() if ldisc presentDmitry Safonov
Try to get reference for ldisc during tty_reopen(). If ldisc present, we don't need to do tty_ldisc_reinit() and lock the write side for line discipline semaphore. Effectively, it optimizes fast-path for tty_reopen(), but more importantly it won't interrupt ongoing IO on the tty as no ldisc change is needed. Fixes user-visible issue when tty_reopen() interrupted login process for user with a long password, observed and reported by Lukas. Fixes: c96cf923a98d ("tty: Don't block on IO when ldisc change is pending") Fixes: 83d817f41070 ("tty: Hold tty_ldisc_lock() during tty_reopen()") Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Lukas F. Hartmann <lukas@mntmn.com> Tested-by: Lukas F. Hartmann <lukas@mntmn.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-10Merge 4.20-rc6 into tty-nextGreg Kroah-Hartman
We want the TTY changes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: Simplify tty->count math in tty_reopen()Dmitry Safonov
As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter. Simplify math by increasing the counter after reinit success. Cc: Jiri Slaby <jslaby@suse.com> Link: lkml.kernel.org/r/<20180829022353.23568-2-dima@arista.com> Suggested-by: Jiri Slaby <jslaby@suse.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: Hold tty_ldisc_lock() during tty_reopen()Dmitry Safonov
tty_ldisc_reinit() doesn't race with neither tty_ldisc_hangup() nor set_ldisc() nor tty_ldisc_release() as they use tty lock. But it races with anyone who expects line discipline to be the same after hoding read semaphore in tty_ldisc_ref(). We've seen the following crash on v4.9.108 stable: BUG: unable to handle kernel paging request at 0000000000002260 IP: [..] n_tty_receive_buf_common+0x5f/0x86d Workqueue: events_unbound flush_to_ldisc Call Trace: [..] n_tty_receive_buf2 [..] tty_ldisc_receive_buf [..] flush_to_ldisc [..] process_one_work [..] worker_thread [..] kthread [..] ret_from_fork tty_ldisc_reinit() should be called with ldisc_sem hold for writing, which will protect any reader against line discipline changes. Cc: Jiri Slaby <jslaby@suse.com> Cc: stable@vger.kernel.org # b027e2298bd5 ("tty: fix data race between tty_init_dev and flush of buf") Reviewed-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+3aa9784721dfb90e984d@syzkaller.appspotmail.com Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Dmitry Safonov <dima@arista.com> Tested-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05USB: serial: console: fix reported terminal settingsJohan Hovold
The USB-serial console implementation has never reported the actual terminal settings used. Despite storing the corresponding cflags in its struct console, these were never honoured on later tty open() where the tty termios would be left initialised to the driver defaults. Unlike the serial console implementation, the USB-serial code calls subdriver open() already at console setup. While calling set_termios() and write() before open() looks like it could work for some USB-serial drivers, others definitely do not expect this, so modelling this after serial core is going to be intrusive, if at all possible. Instead, use a (renamed) tty helper to save the termios data used at console setup so that the tty termios reflects the actual terminal settings after a subsequent tty open(). Note that the calls to tty_init_termios() (tty_driver_install()) and tty_save_termios() are serialised using the disconnect mutex. This specifically fixes a regression that was triggered by a recent change adding software flow control to the pl2303 driver: a getty trying to disable flow control while leaving the baud rate unchanged would now also set the baud rate to the driver default (prior to the flow-control change this had been a noop). Fixes: 7041d9c3f01b ("USB: serial: pl2303: add support for tx xon/xoff flow control") Cc: stable <stable@vger.kernel.org> # 4.18 Cc: Florian Zumbiehl <florz@florz.de> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org>
2018-10-29Merge tag 'tty-4.20-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial updates from Greg KH: "Here is the big tty and serial pull request for 4.20-rc1 Lots of little things here, including a merge from the SPI tree in order to keep things simpler for everyone to sync around for one platform. Major stuff is: - tty buffer clearing after use - atmel_serial fixes and additions - xilinx uart driver updates and of course, lots of tiny fixes and additions to individual serial drivers. All of these have been in linux-next with no reported issues for a while" * tag 'tty-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (66 commits) of: base: Change logic in of_alias_get_alias_list() of: base: Fix english spelling in of_alias_get_alias_list() serial: sh-sci: do not warn if DMA transfers are not supported serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES tty: check name length in tty_find_polling_driver() serial: sh-sci: Add r8a77990 support tty: wipe buffer if not echoing data tty: wipe buffer. serial: fsl_lpuart: Remove the alias node dependence TTY: sn_console: Replace spin_is_locked() with spin_trylock() Revert "serial:serial_core: Allow use of CTS for PPS line discipline" serial: 8250_uniphier: add auto-flow-control support serial: 8250_uniphier: flatten probe function serial: 8250_uniphier: remove unused "fifo-size" property dt-bindings: serial: sh-sci: Document r8a7744 bindings serial: uartps: Fix missing unlock on error in cdns_get_id() tty/serial: atmel: add ISO7816 support tty/serial_core: add ISO7816 infrastructure serial:serial_core: Allow use of CTS for PPS line discipline serial: docs: Fix filename for serial reference implementation ...
2018-10-24Merge branch 'work.tty-ioctl' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull tty ioctl updates from Al Viro: "This is the compat_ioctl work related to tty ioctls. Quite a bit of dead code taken out, all tty-related stuff gone from fs/compat_ioctl.c. A bunch of compat bugs fixed - some still remain, but all more or less generic tty-related ioctls should be covered (remaining issues are in things like driver-private ioctls in a pcmcia serial card driver not getting properly handled in 32bit processes on 64bit host, etc)" * 'work.tty-ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (53 commits) kill TIOCSERGSTRUCT change semantics of ldisc ->compat_ioctl() kill TIOCSER[SG]WILD synclink_gt(): fix compat_ioctl() pty: fix compat ioctls compat_ioctl - kill keyboard ioctl handling gigaset: add ->compat_ioctl() vt_compat_ioctl(): clean up, use compat_ptr() properly gigaset: don't try to printk userland buffer contents dgnc: don't bother with (empty) stub for TCXONC dgnc: leave TIOC[GS]SOFTCAR to ldisc remove fallback to drivers for TIOCGICOUNT dgnc: break-related ioctls won't reach ->ioctl() kill the rest of tty COMPAT_IOCTL() entries dgnc: TIOCM... won't reach ->ioctl() isdn_tty: TCSBRK{,P} won't reach ->ioctl() kill capinc_tty_ioctl() take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl() synclink: reduce pointless checks in ->ioctl() complete ->[sg]et_serial() switchover ...