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2022-09-22tty: n_hdlc: remove HDLC_MAGICнаб1-27/+0
According to Greg, in the context of magic numbers as defined in magic-number.rst, "the tty layer should not need this and I'll gladly take patches" Acked-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz> Ref: https://lore.kernel.org/linux-doc/YyMlovoskUcHLEb7@kroah.com/ Link: https://lore.kernel.org/r/c31d228302da3f426cebf6fcff855181a5590a66.1663288066.git.nabijaczleweli@nabijaczleweli.xyz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-30termios: get rid of stray asm/termios.h include in n_hdlc.cAl Viro1-1/+0
that's the only one outside of include/uapi/linux/termios.h and it's not even needed there - we have linux/tty.h already pulled and that pulls linux/termios.h Normally I would not consider that a sufficient reason, but there's a plenty of linux/tty.h users, and this is the only one that follows that with asm/termios.h. The situation with termios.h is genuinely convoluted, and this complicates it for no good reason. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/r/20220821010239.1554132-2-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-20Merge 5.16-rc6 into tty-nextGreg Kroah-Hartman1-1/+22
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-15tty: n_hdlc: make n_hdlc_tty_wakeup() asynchronousTetsuo Handa1-1/+22
syzbot is reporting that an unprivileged user who logged in from tty console can crash the system using a reproducer shown below [1], for n_hdlc_tty_wakeup() is synchronously calling n_hdlc_send_frames(). ---------- #include <sys/ioctl.h> #include <unistd.h> int main(int argc, char *argv[]) { const int disc = 0xd; ioctl(1, TIOCSETD, &disc); while (1) { ioctl(1, TCXONC, 0); write(1, "", 1); ioctl(1, TCXONC, 1); /* Kernel panic - not syncing: scheduling while atomic */ } } ---------- Linus suspected that "struct tty_ldisc"->ops->write_wakeup() must not sleep, and Jiri confirmed it from include/linux/tty_ldisc.h. Thus, defer n_hdlc_send_frames() from n_hdlc_tty_wakeup() to a WQ context like net/nfc/nci/uart.c does. Link: https://syzkaller.appspot.com/bug?extid=5f47a8cea6a12b77a876 [1] Reported-by: syzbot <syzbot+5f47a8cea6a12b77a876@syzkaller.appspotmail.com> Cc: stable <stable@vger.kernel.org> Analyzed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Confirmed-by: Jiri Slaby <jirislaby@kernel.org> Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: https://lore.kernel.org/r/40de8b7e-a3be-4486-4e33-1b1d1da452f8@i-love.sakura.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-25tty: remove file from tty_ldisc_ops::ioctl and compat_ioctlJiri Slaby1-3/+2
After the previous patches, noone needs 'file' parameter in neither ioctl hook from tty_ldisc_ops. So remove 'file' from both of them. Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> [NFC] Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20211122094529.24171-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22tty: remove file from n_tty_ioctl_helperJiri Slaby1-1/+1
After the previous patch, there are no users of 'file' in n_tty_ioctl_helper. So remove it also from there. Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210914091134.17426-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20tty: n_hdlc: Fix a little doc-rot in n_hdlc_tty_read()Lee Jones1-1/+3
Fixes the following W=1 kernel build warning(s): drivers/tty/n_hdlc.c:421: warning: Function parameter or member 'kbuf' not described in 'n_hdlc_tty_read' drivers/tty/n_hdlc.c:421: warning: Function parameter or member 'cookie' not described in 'n_hdlc_tty_read' drivers/tty/n_hdlc.c:421: warning: Function parameter or member 'offset' not described in 'n_hdlc_tty_read' drivers/tty/n_hdlc.c:421: warning: Excess function parameter 'buf' description in 'n_hdlc_tty_read' Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Paul Fulghum <paulkf@microgate.com> Cc: Michael Callahan <callahan@maths.ox.ac.uk> Cc: Al Longyear <longyear@netcom.com> Cc: Paul Mackerras <Paul.Mackerras@cs.anu.edu.au> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20210520121906.3468725-9-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: no checking of tty_unregister_ldiscJiri Slaby1-7/+1
tty_unregister_ldisc now returns 0 = success. No need to check the return value. In fact, the users only warned if an error occured and didn't do anything useful anyway -- the ldisc module was unloaded in any case. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@reisers.ca> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Rodolfo Giometti <giometti@enneenne.com> Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Link: https://lore.kernel.org/r/20210505091928.22010-19-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: make tty_ldisc_ops a param in tty_unregister_ldiscJiri Slaby1-2/+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 <jslaby@suse.cz> Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@reisers.ca> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Rodolfo Giometti <giometti@enneenne.com> Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Link: https://lore.kernel.org/r/20210505091928.22010-17-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: set tty_ldisc_ops::num staticallyJiri Slaby1-1/+2
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 <jslaby@suse.cz> Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@reisers.ca> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Rodolfo Giometti <giometti@enneenne.com> Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Link: https://lore.kernel.org/r/20210505091928.22010-15-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <jslaby@suse.cz> Cc: William Hubbs <w.d.hubbs@gmail.com> Cc: Chris Brannon <chris@the-brannons.com> Cc: Kirk Reiser <kirk@reisers.ca> Cc: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Mark Brown <broonie@kernel.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com> Link: https://lore.kernel.org/r/20210505091928.22010-12-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15tty: clean include/linux/tty.h upGreg Kroah-Hartman1-0/+1
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 <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20210408125134.3016837-14-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10tty: remove TTY_LDISC_MAGICJiri Slaby1-1/+0
First, it is never checked. Second, use of it as a debugging aid is at least questionable. With the current tools, I don't think anyone used this kind of thing for debugging purposes for years. On the top of that, e.g. serdev does not set this field of tty_ldisc_ops at all. So get rid of this legacy. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-20tty: convert tty_ldisc_ops 'read()' function to take a kernel pointerLinus Torvalds1-19/+41
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>
2020-08-31Merge 5.9-rc3 into tty-nextGreg Kroah-Hartman1-1/+1
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-18tty: ldiscs, fix kernel-docJiri Slaby1-36/+36
As in the previous patch, fix kernel-doc in line disciplines. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085655.12071-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-29n_hdlc_tty_read(): remove pointless access_ok()Al Viro1-7/+0
only copy_to_user() is done to the address in question Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-16tty: n_hdlc, remove FILE and LINE from pr_debugJiri Slaby1-21/+12
As Joe suggests, dynamic debug can print module name and line number along with message. So remove __FILE__ and __LINE__ from all those pr_debug calls. Out of curiosity, I measured the savings, 200 bytes of code are gone. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Suggested-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/20200316064910.4941-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: wrap a comment properlyJiri Slaby1-2/+4
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-24-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: fix whitespace around binary operatorsJiri Slaby1-3/+3
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-23-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: add missing spaces after commasJiri Slaby1-9/+9
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-22-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove spaces between function name and (Jiri Slaby1-4/+4
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-21-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove useless whitespace at line wrapsJiri Slaby1-37/+37
Do s@[ \t]\+$@@ s@ \+\t@\t@ on the file as there are many spaces at the begininning of lines and many spaces/tabs at EOLs. And vim screamed. git show -w is supposed to show no difference here. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-20-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: use __func__ and pr_ print helpersJiri Slaby1-7/+7
* we mark the message in n_hdlc_tty_receive as error * we use __func__ instead of explicit function name * we switch the remaining prints to pr_* helpers Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-19-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unneeded ifdefJiri Slaby1-2/+0
TTY_NO_WRITE_SPLIT is (always) defined in linux/tty.h, so no need to check for it. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-18-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: switch tbusy and woke_up to boolsJiri Slaby1-8/+8
They are in fact bools, so save some bytes (8B on x86_64). Also describe @woke_up as we know what it is. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-17-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: move tty_ldisc_ops to the bottomJiri Slaby1-31/+15
This makes forward declarations unnecessary. So drop them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-16-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: add helper for buffers allocationJiri Slaby1-22/+20
Given both rx and tx allocations do the same, add a new helper (n_hdlc_alloc_buf) and use it for both of them. This cleans up n_hdlc_alloc slightly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-15-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove checking of n_hdlcJiri Slaby1-29/+3
We got rid of backup_tty recently. Also, the tty layer ensures not to call other ldisc hooks after ldisc close. That means, all those tests are superfluous now so remove them. Note that we remove the magic check in write after schedule too. The tty cannot change during schedule. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-14-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove cached ttyJiri Slaby1-16/+5
It's not needed, as now it's clear, that it's always the same as the one passed from the tty layer. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-13-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: inline n_hdlc_releaseJiri Slaby1-25/+10
Put the body of n_hdlc_release into the only caller. It can be seen, that the "if" is superfluous now -- the same happens few lines above in n_hdlc_tty_close already. So drop it. Drop also n_hdlc2tty macro as this was the only user. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-12-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: expand tty2n_hdlc macroJiri Slaby1-12/+11
It's simple tty->disc_data, but it obfuscates code. So expand it to all locations and drop it. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-11-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unused backup_ttyJiri Slaby1-9/+1
It's only set to NULL and never properly used. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unused flagsJiri Slaby1-4/+1
They are only set to 0 and never read. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: invert conditions in n_hdlc_tty_close and n_hdlc_tty_pollJiri Slaby1-34/+38
This makes the functions return immediatelly on invalid state. And we can push the indent of the later code one level left. Pass "-w" to "git show" to see we are changing only the conditions (and whitespace). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: simplify freeing of buffer listJiri Slaby1-31/+14
n_hdlc_release contains four loops to free each buffer list. Create a helper (n_hdlc_free_buf_list) and call it for every list instead. It makes n_hdlc_release more readable. We are switching from "for (;;)" to "do {} while (buf)" which avoids the "if (buf)" completely -- kfree is a nop for NULL pointers. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: use clamp() for maxframeJiri Slaby1-4/+1
It is easier to read. And use MAX_HDLC_FRAME_SIZE instead of magic constant. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: cleanup messages during registrationJiri Slaby1-4/+4
1) n_hdlc prints two lines during registration. Squeeze it into one. 2) prefix the error message with "N_HDLC: ", so that it's clear which ldisc failed to register. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: put init/exit strings directly to printsJiri Slaby1-22/+6
These strings were put aside from prints to save some bytes after module load or when built-in -- they were freed after module load (__init ones) or when the driver is selected as built-in (__exit ones). The savings are negligible, but the code readability is worse by the order of magnitude. So put the strings where they belong. Note that it also used to make little sense putting const data in .data (the __exit case). While at it, switch to pr_info, pr_err, not using the KERN_INFO and _ERR directly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: convert debuglevel use to pr_debugJiri Slaby1-48/+31
With pr_debug we have a fine-grained control about debugging prints. So convert the use of global debuglevel variable and tests to a commonly used pr_debug. And drop debuglevel completely. This also implicitly adds a loglevel to the messages (KERN_DEBUG) as it was missing on most of them. And also use __func__ instead of function names explicitly typed. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove unused macrosJiri Slaby1-5/+0
VERSION and bset are unused. Remove them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-21n_hdlc: remove tracing debug printsJiri Slaby1-30/+2
We can trace functions using ftrace, so there is no need for this additional prints. Remove them. We keep only those which print some additional info, not only function name & "entry"/"exit". Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084118.26491-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23tty: n_hdlc: Use flexible-array member and struct_size() helperGustavo A. R. Silva1-6/+5
Old code in the kernel uses 1-byte and 0-byte arrays to indicate the presence of a "variable length array": struct something { int length; u8 data[1]; }; struct something *instance; instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL); instance->length = size; memcpy(instance->data, source, size); There is also 0-byte arrays. Both cases pose confusion for things like sizeof(), CONFIG_FORTIFY_SOURCE, etc.[1] Instead, the preferred mechanism to declare variable-length types such as the one above is a flexible array member[2] which need to be the last member of a structure and empty-sized: struct something { int stuff; u8 data[]; }; Also, by making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. Lastly, make use of the struct_size() helper to safely calculate the allocation size for instances of struct n_hdlc_buf and avoid any potential type mistakes[4][5]. [1] https://github.com/KSPP/linux/issues/21 [2] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") [4] https://lore.kernel.org/lkml/60e14fb7-8596-e21c-f4be-546ce39e7bdb@embeddedor.com/ [5] commit 553d66cb1e86 ("iommu/vt-d: Use struct_size() helper") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200121172138.GA3162@embeddedor Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04tty: n_hdlc: fix build on SPARCRandy Dunlap1-0/+5
Fix tty driver build on SPARC by not using __exitdata. It appears that SPARC does not support section .exit.data. Fixes these build errors: `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o `.exit.data' referenced in section `.exit.text' of drivers/tty/n_hdlc.o: defined in discarded section `.exit.data' of drivers/tty/n_hdlc.o Reported-by: kbuild test robot <lkp@intel.com> Fixes: 063246641d4a ("format-security: move static strings to const") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/675e7bd9-955b-3ff3-1101-a973b58b5b75@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-14tty/n_hdlc: mark expected switch fall-throughGustavo A. R. Silva1-1/+1
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. This patch fixes the following warning: drivers/tty/n_hdlc.c: In function ‘n_hdlc_tty_ioctl’: drivers/tty/n_hdlc.c:775:3: warning: this statement may fall through [-Wimplicit-fallthrough=] switch (arg) { ^~~~~~ drivers/tty/n_hdlc.c:782:2: note: here default: ^~~~~~~ Warning level 3 was used: -Wimplicit-fallthrough=3 Notice that, in this particular case, the code comment is modified in accordance with what GCC is expecting to find. This patch is part of the ongoing efforts to enable -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18tty/n_hdlc: fix __might_sleep warningPaul Fulghum1-0/+1
Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE. This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE. The loop breaks out and sets TASK_RUNNING after calling copy_to_user. This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user. [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324 Signed-off-by: Paul Fulghum <paulkf@microgate.com> Reported-by: syzbot <syzbot+c244af085a0159d22879@syzkaller.appspotmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: stable <stable@vger.kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds1-1/+1
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-05tty: Don't block on IO when ldisc change is pendingDmitry Safonov1-2/+2
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 <jslaby@suse.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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