aboutsummaryrefslogtreecommitdiff
path: root/include/linux/tty.h
AgeCommit message (Collapse)AuthorFilesLines
2021-09-22tty: remove file from n_tty_ioctl_helperJiri Slaby1-2/+2
After the previous patch, there are no users of 'file' in n_tty_ioctl_helper. So remove it also from there. Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Krzysztof Kozlowski <[email protected]> Acked-by: Krzysztof Kozlowski <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-09-22tty: remove file from tty_mode_ioctlJiri Slaby1-2/+1
The only user of 'file' parameter in tty_mode_ioctl is a BUG_ON check. Provided it never crashed for anyone, it's an overkill to pass the parameter to tty_mode_ioctl only for this check. If we wanted to check 'file' there, we should handle it in more graceful way anyway. Not by a BUG == crash. Cc: Wolfgang Grandegger <[email protected]> Cc: Marc Kleine-Budde <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Andreas Koensgen <[email protected]> Cc: Paul Mackerras <[email protected]> Acked-by: Marc Kleine-Budde <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-09-22tty: remove extern from functions in tty headersJiri Slaby1-70/+69
After the recent headers cleanup, some function declarations still have extern before them. It is superfluous (for function declarations), so remove extern from those which still have it. This unifies them with the rest of the files. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-07-27tty: move tty_port to new tty_port.hJiri Slaby1-195/+1
tty.h is long enough already. And I am slowly adding kernel-doc documentation, so it grows to unmaintainable long mess. To avoid this, split tty.h further into tty_port.h and move there tty_port-related declarations and function prototypes (those implemented in tty_port.c). Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-07-27tty: move tty_buffer definitions to new tty_buffer.hJiri Slaby1-48/+1
tty.h is large enough currently. And I am slowly adding kernel-doc documentation, so it grows to unmaintainable long mess. To avoid this, split tty.h further into tty_buffer.h and move there tty_buffer-related declarations and function prototypes. Note that many of the tty_buffer.c function prototypes reside now in tty_flip.h. But we cannot move struct tty_buffer & friends because: * tty_insert_flip_char() in tty_flip.h needs both struct tty_port and struct tty_buffer defined. * struct tty_port in tty_port.h needs struct tty_buffer defined. So if we moved struct tty_buffer to tty_flip.h too, tty_flip.h would need tty_port.h and that would need tty_flip.h (to have tty_buffer) again. Hence we introduce new header tty_buffer.h here to break this circular dependency. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-07-27tty: move tty_ldisc_receive_buf to tty_flip.hJiri Slaby1-3/+0
It's the only remaining tty_buffer.c prototype residing in tty.h. Move it along others to tty_flip.h. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-07-27tty: move ldisc prototypes to tty_ldisc.hJiri Slaby1-10/+0
We already have tty_ldisc.h, so cleanup tty.h a bit by moving out tty_ldisc-related function prototypes and a variable into tty_ldisc.h. They are implemented in tty_ldisc.c anyway. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-07-27tty: move tty_driver related prototypes to tty_driver.hJiri Slaby1-17/+0
We already have tty_driver.h, so cleanup tty.h a bit by moving out tty_driver-related function prototypes into tty_driver.h. Note that tty.h already includes tty_driver.h. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-06-15tty: make tty_get_{char,frame}_size availableJiri Slaby1-0/+3
Many tty drivers contain code to compute bits count depending on termios cflags. So extract this code from serial core to two separate tty helper functions: * tty_get_char_size -- only size of a character, without flags, * tty_get_frame_size -- complete size of a frame including flags. In the next patch, calls to these new functions replace many copies of this code. Note that we accept only cflag as a parameter. That's because some callers like pch_uart_startup or sunsab_console_setup don't have at hand termios which we could pass around. Cc: Joe Perches <[email protected]> Cc: Johan Hovold <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: remove unused tty_throttleJiri Slaby1-1/+0
The last user was removed in commit e91e52e42814 (n_tty: Fix stuck throttled driver) in 2013. So remove exported tty_throttle completely. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: make tty_operations::chars_in_buffer return uintJiri Slaby1-1/+1
tty_operations::chars_in_buffer is another hook which is expected to return values >= 0. So make it explicit by the return type too -- use unsigned int. Signed-off-by: Jiri Slaby <[email protected]> Acked-By: Anton Ivanov <[email protected]> Acked-by: David Sterba <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Samuel Iglesias Gonsalvez <[email protected]> Cc: Jens Taprogge <[email protected]> Cc: Karsten Keil <[email protected]> Cc: Ulf Hansson <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: David Lin <[email protected]> Cc: Johan Hovold <[email protected]> Cc: Alex Elder <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Shawn Guo <[email protected]> Cc: Sascha Hauer <[email protected]> Cc: Oliver Neukum <[email protected]> Cc: Felipe Balbi <[email protected]> Cc: Mathias Nyman <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: make tty_operations::write_room return uintJiri Slaby1-1/+1
Line disciplines expect a positive value or zero returned from tty->ops->write_room (invoked by tty_write_room). So make this assumption explicit by using unsigned int as a return value. Both of tty->ops->write_room and tty_write_room. Signed-off-by: Jiri Slaby <[email protected]> Acked-by: Laurentiu Tudor <[email protected]> Acked-by: Alex Elder <[email protected]> Acked-by: Max Filippov <[email protected]> # xtensa Acked-by: David Sterba <[email protected]> Acked-By: Anton Ivanov <[email protected]> Acked-by: Geert Uytterhoeven <[email protected]> Cc: Richard Henderson <[email protected]> Cc: Ivan Kokshaysky <[email protected]> Cc: Matt Turner <[email protected]> Cc: "James E.J. Bottomley" <[email protected]> Cc: Helge Deller <[email protected]> Cc: Jeff Dike <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Chris Zankel <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Samuel Iglesias Gonsalvez <[email protected]> Cc: Jens Taprogge <[email protected]> Cc: Karsten Keil <[email protected]> Cc: Scott Branden <[email protected]> Cc: Ulf Hansson <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: David Lin <[email protected]> Cc: Johan Hovold <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Shawn Guo <[email protected]> Cc: Sascha Hauer <[email protected]> Cc: Oliver Neukum <[email protected]> Cc: Felipe Balbi <[email protected]> Cc: Mathias Nyman <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: return void from tty_unregister_ldiscJiri Slaby1-1/+1
Now that noone checks the return value of tty_unregister_ldisc, make the function return 'void'. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: make tty_ldisc_ops a param in tty_unregister_ldiscJiri Slaby1-1/+1
Make tty_unregister_ldisc symmetric to tty_register_ldisc by accepting struct tty_ldisc_ops as a parameter instead of ldisc number. This avoids checking of the ldisc number bounds in tty_unregister_ldisc. Signed-off-by: Jiri Slaby <[email protected]> Cc: William Hubbs <[email protected]> Cc: Chris Brannon <[email protected]> Cc: Kirk Reiser <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Wolfgang Grandegger <[email protected]> Cc: Marc Kleine-Budde <[email protected]> Cc: Andreas Koensgen <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Rodolfo Giometti <[email protected]> Cc: Peter Ujfalusi <[email protected]> Cc: Liam Girdwood <[email protected]> Cc: Mark Brown <[email protected]> Cc: Jaroslav Kysela <[email protected]> Cc: Takashi Iwai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: set tty_ldisc_ops::num staticallyJiri Slaby1-1/+1
There is no reason to pass the ldisc number to tty_register_ldisc separately. Just set it in the already defined tty_ldisc_ops in all the ldiscs. This simplifies tty_register_ldisc a bit too (no need to set the num member there). Signed-off-by: Jiri Slaby <[email protected]> Cc: William Hubbs <[email protected]> Cc: Chris Brannon <[email protected]> Cc: Kirk Reiser <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Wolfgang Grandegger <[email protected]> Cc: Marc Kleine-Budde <[email protected]> Cc: Andreas Koensgen <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Rodolfo Giometti <[email protected]> Cc: Peter Ujfalusi <[email protected]> Cc: Liam Girdwood <[email protected]> Cc: Mark Brown <[email protected]> Cc: Jaroslav Kysela <[email protected]> Cc: Takashi Iwai <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: cumulate and document tty_struct::ctrl* membersJiri Slaby1-10/+16
Group the ctrl members under a single struct called ctrl. The new struct contains 'pgrp', 'session', 'pktstatus', and 'packet'. 'pktstatus' and 'packet' used to be bits in a bitfield. The struct also contains the lock protecting them to share the same cache line. Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty flow control changes) added a padding to the original bitfield. It was for the bitfield to occupy a whole 64b word to avoid interferring stores on Alpha (cannot we evaporate this arch with weird implications to C code yet?). But it doesn't work as expected as the padding (tty_struct::ctrl_unused) is aligned to a 8B boundary too and occupies some bytes from the next word. So make it reliable by: 1) setting __aligned of the struct -- that aligns the start, and 2) making 'unsigned long unused[0]' as the last member of the struct -- pads the end. Add a kerneldoc comment for this grouped members. Signed-off-by: Jiri Slaby <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: cumulate and document tty_struct::flow* membersJiri Slaby1-16/+22
Group the flow flags under a single struct called flow. The new struct contains 'stopped' and 'tco_stopped' bools which used to be bits in a bitfield. The struct also contains the lock protecting them to potentially share the same cache line. Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty flow control changes) added a padding to the original bitfield. It was for the bitfield to occupy a whole 64b word to avoid interferring stores on Alpha (cannot we evaporate this arch with weird implications to C code yet?). But it doesn't work as expected as the padding (tty_struct::unused) is aligned to a 8B boundary too and occupies some bytes from the next word. So make it reliable by: 1) setting __aligned of the struct -- that aligns the start, and 2) making 'unsigned long unused[0]' as the last member of the struct -- pads the end. This is also the perfect time to start the documentation of tty_struct where all this lives. So we start by documenting what these bools actually serve for. And why we do all the alignment dances. Only the few up-to-date information from the Theodore's comment made it into this new Kerneldoc comment. Signed-off-by: Jiri Slaby <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Ulf Hansson <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Shawn Guo <[email protected]> Cc: Sascha Hauer <[email protected]> Cc: Vineet Gupta <[email protected]> Cc: "Maciej W. Rozycki" <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-05-13tty: make fp of tty_ldisc_ops::receive_buf{,2} constJiri Slaby1-1/+1
Char pointer (cp) passed to tty_ldisc_ops::receive_buf{,2} is const. There is no reason for flag pointer (fp) not to be too. So switch it in the definition and all uses. Signed-off-by: Jiri Slaby <[email protected]> Cc: William Hubbs <[email protected]> Cc: Chris Brannon <[email protected]> Cc: Kirk Reiser <[email protected]> Cc: Samuel Thibault <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: Johan Hedberg <[email protected]> Cc: Luiz Augusto von Dentz <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Wolfgang Grandegger <[email protected]> Cc: Marc Kleine-Budde <[email protected]> Cc: Andreas Koensgen <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Liam Girdwood <[email protected]> Cc: Mark Brown <[email protected]> Cc: Jaroslav Kysela <[email protected]> Cc: Takashi Iwai <[email protected]> Cc: Peter Ujfalusi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-04-15tty: clean include/linux/tty.h upGreg Kroah-Hartman1-34/+0
There are a lot of tty-core-only functions that are listed in include/linux/tty.h. Move them to drivers/tty/tty.h so that no one else can accidentally call them or think that they are public functions. Cc: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-04-15tty: move some tty-only functions to drivers/tty/tty.hGreg Kroah-Hartman1-16/+0
The flow change and restricted_tty_write() logic is internal to the tty core only, so move it out of the include/linux/tty.h file. Cc: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-04-15tty: make tty_release_redirect() staticGreg Kroah-Hartman1-1/+0
No one calls this outside of the tty_io.c file, so mark this static and do not export the symbol anymore. Cc: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-04-15tty: move some internal tty lock enums and functions out of tty.hGreg Kroah-Hartman1-26/+0
Move the TTY_LOCK_* enums and tty_ldisc lock functions out of the global tty.h into the local header file to clean things up. Cc: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-04-15tty: audit: move some local functions out of tty.hGreg Kroah-Hartman1-10/+0
The functions tty_audit_add_data() and tty_audit_tiocsti() are local to the tty core code, and do not need to be in a "kernel-wide" header file so move them to drivers/tty/tty.h Cc: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-04-15tty: create internal tty.h fileGreg Kroah-Hartman1-12/+0
There are a number of functions and #defines in include/linux/tty.h that do not belong there as they are private to the tty core code. Create an initial drivers/tty/tty.h file and copy the odd "tty logging" macros into it to seed the file with some initial things that we know nothing outside of the tty core should be calling. Cc: Tetsuo Handa <[email protected]> Cc: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-04-10tty: clarify that not all ttys have a class deviceJohan Hovold1-1/+1
Commit 30004ac9c090 ("tty: add tty_struct->dev pointer to corresponding device instance") added a struct device pointer field to struct tty_struct which was populated with the corresponding tty class device during initialisation. Unfortunately, not all ttys have a class device (e.g. pseudoterminals and serdev) in which case the device pointer will be set to NULL, something which have bit driver authors over the years. In retrospect perhaps this field should never have been added, but let's at least document the current behaviour. Signed-off-by: Johan Hovold <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-03-10tty: let tty_unregister_driver return voidJiri Slaby1-1/+1
Now that noone checks the return value, switch the return type of tty_unregister_driver to void. We can do that as we always return zero. Generally, drivers are not allowed to call tty_unregister_driver while there are open devices. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-02-20Merge tag 'tty-5.12-rc1' of ↵Linus Torvalds1-4/+7
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 ...
2021-01-25Commit 9bb48c82aced ("tty: implement write_iter") converted the ttySami Tolvanen1-0/+1
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 <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-01-07tty: Export redirect releaseCorey Minyard1-0/+1
This will be required by the pty code when it removes tty_vhangup() on master close. Signed-off-by: Corey Minyard <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2021-01-07tty_port: drop last traces of low_latencyJiri Slaby1-2/+1
The main purpose of tty_port::low_latency was removed in commit a9c3f68f3cd8 (tty: Fix low_latency BUG) back in 2014. It was left in place for drivers as an optional tune knob. But only one driver has been using it until the previous commit. So remove this misconcept completely, given there are no users. Signed-off-by: Jiri Slaby <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-12-28tty: new helper function tty_get_icount()Uwe Kleine-König1-0/+2
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 <[email protected]> Signed-off-by: Uwe Kleine-König <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-12-28tty: rename tty_kopen() and add new function tty_kopen_shared()Uwe Kleine-König1-2/+3
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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-12-09tty: use const parameters in port-flag accessorsJohan Hovold1-6/+6
Declare the port parameter to the flag-test accessors as const. This is currently mostly cosmetic as the accessors are already inlined. Suggested-by: Jiri Slaby <[email protected]> Signed-off-by: Johan Hovold <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-12-09tty: use assign_bit() in port-flag accessorsJohan Hovold1-24/+6
Use the new assign_bit() wrapper in the port-flag accessors instead of open coding. Suggested-by: Jiri Slaby <[email protected]> Signed-off-by: Johan Hovold <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-12-07Merge 5.10-rc7 into tty-nextGreg Kroah-Hartman1-0/+4
We want the tty fixes in here as well. Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-12-04tty: Fix ->session lockingJann Horn1-0/+4
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: [email protected] Signed-off-by: Jann Horn <[email protected]> Reviewed-by: Jiri Slaby <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-12-04tty: Remove dead termiox codeJann Horn1-1/+0
set_termiox() and the TCGETX handler bail out with -EINVAL immediately if ->termiox is NULL, but there are no code paths that can set ->termiox to a non-NULL pointer; and no such code paths seem to have existed since the termiox mechanism was introduced back in commit 1d65b4a088de ("tty: Add termiox") in v2.6.28. Similarly, no driver actually implements .set_termiox; and it looks like no driver ever has. Delete this dead code; but leave the definition of struct termiox in the UAPI headers intact. Signed-off-by: Jann Horn <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-11-06tty: tty_io: Move 'tty_sysctl_init's prototype to shared spaceLee Jones1-0/+1
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 <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: Nick Holloway <[email protected]> Cc: -- <[email protected]> Cc: Marko Kohtala <[email protected]> Cc: Bill Hawes <[email protected]> Cc: "C. Scott Ananian" <[email protected]> Cc: Russell King <[email protected]> Cc: Andrew Morton <[email protected]> Signed-off-by: Lee Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-05-04gcc-10 warnings: fix low-hanging fruitLinus Torvalds1-1/+1
Due to a bug-report that was compiler-dependent, I updated one of my machines to gcc-10. That shows a lot of new warnings. Happily they seem to be mostly the valid kind, but it's going to cause a round of churn for getting rid of them.. This is the really low-hanging fruit of removing a couple of zero-sized arrays in some core code. We have had a round of these patches before, and we'll have many more coming, and there is nothing special about these except that they were particularly trivial, and triggered more warnings than most. Signed-off-by: Linus Torvalds <[email protected]>
2020-02-10serdev: ttyport: restore client ops on deregistrationJohan Hovold1-0/+2
The serdev tty-port controller driver should reset the tty-port client operations also on deregistration to avoid a NULL-pointer dereference in case the port is later re-registered as a normal tty device. Note that this can only happen with tty drivers such as 8250 which have statically allocated port structures that can end up being reused and where a later registration would not register a serdev controller (e.g. due to registration errors or if the devicetree has been changed in between). Specifically, this can be an issue for any statically defined ports that would be registered by 8250 core when an 8250 driver is being unbound. Fixes: bed35c6dfa6a ("serdev: add a tty port controller driver") Cc: stable <[email protected]> # 4.11 Reported-by: Loic Poulain <[email protected]> Signed-off-by: Johan Hovold <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2018-12-10Merge 4.20-rc6 into tty-nextGreg Kroah-Hartman1-0/+1
We want the TTY changes in here as well. Signed-off-by: Greg Kroah-Hartman <[email protected]>
2018-12-05tty: Don't block on IO when ldisc change is pendingDmitry Safonov1-0/+7
There might be situations where tty_ldisc_lock() has blocked, but there is already IO on tty and it prevents line discipline changes. It might theoretically turn into dead-lock. Basically, provide more priority to pending tty_ldisc_lock() than to servicing reads/writes over tty. User-visible issue was reported by Mikulas where on pa-risc with Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper locking in tty_reopen(). Cc: Jiri Slaby <[email protected]> Reported-by: Mikulas Patocka <[email protected]> Signed-off-by: Dmitry Safonov <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2018-12-05USB: serial: console: fix reported terminal settingsJohan Hovold1-0/+1
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 <[email protected]> # 4.18 Cc: Florian Zumbiehl <[email protected]> Reported-by: Jarkko Nikula <[email protected]> Tested-by: Jarkko Nikula <[email protected]> Acked-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Johan Hovold <[email protected]>
2018-09-14move compat handling of tty ioctls to tty_compat_ioctl()Al Viro1-2/+0
ioctls that are * callable only via tty_ioctl() * not driver-specific * not demand data structure conversions * either always need passing arg as is or always demand compat_ptr() get intercepted in tty_compat_ioctl() from the very beginning and redirecter to tty_ioctl(). As the result, their entries in fs/compat_ioctl.c (some of those had been missing, BTW) got removed, as well as n_tty_compat_ioctl_helper() (now it's never called with any cmd it would accept). Signed-off-by: Al Viro <[email protected]>
2018-06-05Merge tag 'usb-4.18-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB and PHY updates from Greg KH: "Here is the big USB pull request for 4.18-rc1. Lots of stuff here, the highlights are: - phy driver updates and new additions - usual set of xhci driver updates - normal set of musb updates - gadget driver updates and new controllers - typec work, it's getting closer to getting fully out of the staging portion of the tree. - lots of minor cleanups and bugfixes. All of these have been in linux-next for a while with no reported issues" * tag 'usb-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (263 commits) Revert "xhci: Reset Renesas uPD72020x USB controller for 32-bit DMA issue" xhci: Add quirk to zero 64bit registers on Renesas PCIe controllers xhci: Allow more than 32 quirks usb: xhci: force all memory allocations to node selftests: add test for USB over IP driver USB: typec: fsusb302: no need to check return value of debugfs_create_dir() USB: gadget: udc: s3c2410_udc: no need to check return value of debugfs_create functions USB: gadget: udc: renesas_usb3: no need to check return value of debugfs_create functions USB: gadget: udc: pxa27x_udc: no need to check return value of debugfs_create functions USB: gadget: udc: gr_udc: no need to check return value of debugfs_create functions USB: gadget: udc: bcm63xx_udc: no need to check return value of debugfs_create functions USB: udc: atmel_usba_udc: no need to check return value of debugfs_create functions USB: dwc3: no need to check return value of debugfs_create functions USB: dwc2: no need to check return value of debugfs_create functions USB: core: no need to check return value of debugfs_create functions USB: chipidea: no need to check return value of debugfs_create functions USB: ehci-hcd: no need to check return value of debugfs_create functions USB: fhci-hcd: no need to check return value of debugfs_create functions USB: fotg210-hcd: no need to check return value of debugfs_create functions USB: imx21-hcd: no need to check return value of debugfs_create functions ...
2018-05-22tty: add missing const to termios hw-change helperJohan Hovold1-1/+1
Add missing const qualifiers to the parameters of the termios hw-change helper, which is used by a few USB serial drivers. This specifically allows the pl2303 driver to use const arguments in one of its helper as well. Cc: Jiri Slaby <[email protected]> Acked-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Johan Hovold <[email protected]>
2018-05-16proc: introduce proc_create_seq{,_data}Christoph Hellwig1-1/+2
Variants of proc_create{,_data} that directly take a struct seq_operations argument and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <[email protected]>
2018-04-23tty: Don't call panic() at tty_ldisc_init()Tetsuo Handa1-1/+1
syzbot is reporting kernel panic [1] triggered by memory allocation failure at tty_ldisc_get() from tty_ldisc_init(). But since both tty_ldisc_get() and caller of tty_ldisc_init() can cleanly handle errors, tty_ldisc_init() does not need to call panic() when tty_ldisc_get() failed. [1] https://syzkaller.appspot.com/bug?id=883431818e036ae6a9981156a64b821110f39187 Signed-off-by: Tetsuo Handa <[email protected]> Reported-by: syzbot <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Jiri Slaby <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2018-02-28tty: make n_tty_read() always abort if hangup is in progressTejun Heo1-0/+1
A tty is hung up by __tty_hangup() setting file->f_op to hung_up_tty_fops, which is skipped on ttys whose write operation isn't tty_write(). This means that, for example, /dev/console whose write op is redirected_tty_write() is never actually marked hung up. Because n_tty_read() uses the hung up status to decide whether to abort the waiting readers, the lack of hung-up marking can lead to the following scenario. 1. A session contains two processes. The leader and its child. The child ignores SIGHUP. 2. The leader exits and starts disassociating from the controlling terminal (/dev/console). 3. __tty_hangup() skips setting f_op to hung_up_tty_fops. 4. SIGHUP is delivered and ignored. 5. tty_ldisc_hangup() is invoked. It wakes up the waits which should clear the read lockers of tty->ldisc_sem. 6. The reader wakes up but because tty_hung_up_p() is false, it doesn't abort and goes back to sleep while read-holding tty->ldisc_sem. 7. The leader progresses to tty_ldisc_lock() in tty_ldisc_hangup() and is now stuck in D sleep indefinitely waiting for tty->ldisc_sem. The following is Alan's explanation on why some ttys aren't hung up. http://lkml.kernel.org/r/20171101170908.6ad08580@alans-desktop 1. It broke the serial consoles because they would hang up and close down the hardware. With tty_port that *should* be fixable properly for any cases remaining. 2. The console layer was (and still is) completely broken and doens't refcount properly. So if you turn on console hangups it breaks (as indeed does freeing consoles and half a dozen other things). As neither can be fixed quickly, this patch works around the problem by introducing a new flag, TTY_HUPPING, which is used solely to tell n_tty_read() that hang-up is in progress for the console and the readers should be aborted regardless of the hung-up status of the device. The following is a sample hung task warning caused by this issue. INFO: task agetty:2662 blocked for more than 120 seconds. Not tainted 4.11.3-dbg-tty-lockup-02478-gfd6c7ee-dirty #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 0 2662 1 0x00000086 Call Trace: __schedule+0x267/0x890 schedule+0x36/0x80 schedule_timeout+0x23c/0x2e0 ldsem_down_write+0xce/0x1f6 tty_ldisc_lock+0x16/0x30 tty_ldisc_hangup+0xb3/0x1b0 __tty_hangup+0x300/0x410 disassociate_ctty+0x6c/0x290 do_exit+0x7ef/0xb00 do_group_exit+0x3f/0xa0 get_signal+0x1b3/0x5d0 do_signal+0x28/0x660 exit_to_usermode_loop+0x46/0x86 do_syscall_64+0x9c/0xb0 entry_SYSCALL64_slow_path+0x25/0x25 The following is the repro. Run "$PROG /dev/console". The parent process hangs in D state. #include <sys/types.h> #include <sys/stat.h> #include <sys/wait.h> #include <sys/ioctl.h> #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <signal.h> #include <time.h> #include <termios.h> int main(int argc, char **argv) { struct sigaction sact = { .sa_handler = SIG_IGN }; struct timespec ts1s = { .tv_sec = 1 }; pid_t pid; int fd; if (argc < 2) { fprintf(stderr, "test-hung-tty /dev/$TTY\n"); return 1; } /* fork a child to ensure that it isn't already the session leader */ pid = fork(); if (pid < 0) { perror("fork"); return 1; } if (pid > 0) { /* top parent, wait for everyone */ while (waitpid(-1, NULL, 0) >= 0) ; if (errno != ECHILD) perror("waitpid"); return 0; } /* new session, start a new session and set the controlling tty */ if (setsid() < 0) { perror("setsid"); return 1; } fd = open(argv[1], O_RDWR); if (fd < 0) { perror("open"); return 1; } if (ioctl(fd, TIOCSCTTY, 1) < 0) { perror("ioctl"); return 1; } /* fork a child, sleep a bit and exit */ pid = fork(); if (pid < 0) { perror("fork"); return 1; } if (pid > 0) { nanosleep(&ts1s, NULL); printf("Session leader exiting\n"); exit(0); } /* * The child ignores SIGHUP and keeps reading from the controlling * tty. Because SIGHUP is ignored, the child doesn't get killed on * parent exit and the bug in n_tty makes the read(2) block the * parent's control terminal hangup attempt. The parent ends up in * D sleep until the child is explicitly killed. */ sigaction(SIGHUP, &sact, NULL); printf("Child reading tty\n"); while (1) { char buf[1024]; if (read(fd, buf, sizeof(buf)) < 0) { perror("read"); return 1; } } return 0; } Signed-off-by: Tejun Heo <[email protected]> Cc: Alan Cox <[email protected]> Cc: [email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2018-01-23tty: fix data race between tty_init_dev and flush of bufGaurav Kohli1-0/+2
There can be a race, if receive_buf call comes before tty initialization completes in n_tty_open and tty->disc_data may be NULL. CPU0 CPU1 ---- ---- 000|n_tty_receive_buf_common() n_tty_open() -001|n_tty_receive_buf2() tty_ldisc_open.isra.3() -002|tty_ldisc_receive_buf(inline) tty_ldisc_setup() Using ldisc semaphore lock in tty_init_dev till disc_data initializes completely. Signed-off-by: Gaurav Kohli <[email protected]> Reviewed-by: Alan Cox <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>