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path: root/drivers/tty/n_gsm.c
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2022-01-26tty: n_gsm: fix SW flow control encoding/handlingdaniel.starke@siemens.com
n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.2.7.3 states that DC1 (XON) and DC3 (XOFF) are the control characters defined in ISO/IEC 646. These shall be quoted if seen in the data stream to avoid interpretation as flow control characters. ISO/IEC 646 refers to the set of ISO standards described as the ISO 7-bit coded character set for information interchange. Its final version is also known as ITU T.50. See https://www.itu.int/rec/T-REC-T.50-199209-I/en To abide the standard it is needed to quote DC1 and DC3 correctly if these are seen as data bytes and not as control characters. The current implementation already tries to enforce this but fails to catch all defined cases. 3GPP 27.010 chapter 5.2.7.3 clearly states that the most significant bit shall be ignored for DC1 and DC3 handling. The current implementation handles only the case with the most significant bit set 0. Cases in which DC1 and DC3 have the most significant bit set 1 are left unhandled. This patch fixes this by masking the data bytes with ISO_IEC_646_MASK (only the 7 least significant bits set 1) before comparing them with XON (a.k.a. DC1) and XOFF (a.k.a. DC3) when testing which byte values need quotation via byte stuffing. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220120101857.2509-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-25tty: remove file from tty_ldisc_ops::ioctl and compat_ioctlJiri Slaby
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>
2021-11-25n_gsm: remove unused parameters from gsm_error()Jiri Slaby
data and flag are unused in gsm_error(), so remove them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20211118071716.11984-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-05tty: n_gsm: Don't ignore write return value in gsmld_output()Tony Lindgren
We currently have gsmld_output() ignore the return value from device write. This means we will lose packets if device write returns 0 or an error. Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20210930060624.46523-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-05tty: n_gsm: clean up indenting in gsm_queue()Dan Carpenter
These two lines need to be indented one more tab. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20211004104343.GF25015@kili Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22tty: remove file from n_tty_ioctl_helperJiri Slaby
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>
2021-09-14tty: n_gsm: Save dlci address open status when config requesterZhenguo Zhao
When n_gsm config "initiator=0",as requester ,receive SABM frame,n_gsm register gsmtty dev,and save dlci open address status,if receive DLC0 DISC or CLD frame,it can unregister the gsmtty dev by saving dlci address. Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com> Link: https://lore.kernel.org/r/1629461872-26965-8-git-send-email-zhenguo6858@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14tty: n_gsm: Modify gsmtty driver register method when config requesterZhenguo Zhao
As requester,because n_gsm has no uevent report for application,the application can't know dlci connect or disconnect. The application will control every dlcl dev by uevent,when application receive gsmtty0 dev remove uevent,it will close mux function,and change to normal mode. Example: Before modify: gsmld receive DLC0 DISC,no event report to application gsmld receive DLC1 SABM,no event report to application gsmld receive DLC1 DISC,no event report to application After modify: Receive DLC0 DISC,report "/devices/virtual/tty/gsmtty0" remove uevent Receive DLC1 SABM,report "/devices/virtual/tty/gsmtty1" add uevent Receive DLC1 DISC,report "/devices/virtual/tty/gsmtty1" remove uevent Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com> Link: https://lore.kernel.org/r/1629461872-26965-7-git-send-email-zhenguo6858@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14tty: n_gsm: Delete gsmtty open SABM frame when config requesterZhenguo Zhao
When n_gsm config "initiator=0",as requester ,it doesn't need to send SABM frame data during gsmtty open. Example,when gsmtty open,it will send SABM frame.for initiator,it maybe not want to receive the frame. [ 88.410426] c1 gsmld_output: 00000000: f9 07 3f 01 de f9 [ 88.420839] c1 --> 1) R: SABM(F) Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com> Link: https://lore.kernel.org/r/1629461872-26965-6-git-send-email-zhenguo6858@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14tty: n_gsm: Delete gsm_disconnect when config requesterZhenguo Zhao
When n_gsm config "initiator=0",when gsmld config ,as requester ,it doesn't need to send CLD frame data or SABM frame. Example,when tty dev receive "AT+CMUX=0",it will change ldisc n_tty to n_gsm,during config requester,gsmld output "7e 01 ef c3 aa 7e", initiator maybe not want to receive the frame data. [ 154.666457] c1 Q> 0) R: UIH(F) [ 154.669514] c1 C3 [ 154.671519] c1 gsmld_output: 00000000: 7e 01 ef c3 aa 7e [ 155.014874] c1 Q> 0) R: UIH(F) [ 155.018000] c1 C3 [ 155.020046] c1 gsmld_output: 00000000: 7e 01 ef c3 aa 7e [ 155.364425] c1 Q> 0) R: UIH(F) [ 155.367546] c1 C3 [ 155.369597] c1 gsmld_output: 00000000: 7e 01 ef c3 aa 7e Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com> Link: https://lore.kernel.org/r/1629461872-26965-5-git-send-email-zhenguo6858@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14tty: n_gsm: Modify CR,PF bit printk info when config requesterZhenguo Zhao
When n_gsm config "initiator=0",as requester,gsmld receives dlci SABM/DISC control command frame,UA frame printk info is error. Example: Gsmld send UA frame "f9 03 73 01 d7 f9",but CR,PF bit printk info looks like error. Kernel test log as follows: Before modify [ 78.837626] c0 gsmld_receive: 00000000: f9 03 3f 01 1c f9 [ 78.846356] c0 <-- 0) C: SABM(P) [ 78.854021] c0 gsmld_output: 00000000: f9 03 73 01 d7 f9 [ 78.862574] c0 --> 0) C: UA(P) After modify [ 261.233188] c0 gsmld_receive: 00000000: f9 03 3f 01 1c f9 [ 261.242767] c0 <-- 0) C: SABM(P) [ 261.250497] c0 gsmld_output: 00000000: f9 03 73 01 d7 f9 [ 261.259759] c0 --> 0) R: UA(F) Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com> Link: https://lore.kernel.org/r/1629461872-26965-4-git-send-email-zhenguo6858@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14tty: n_gsm: Modify CR,PF bit when config requesterZhenguo Zhao
When n_gsm config "initiator=0",as requester,gsmld receives dlci SABM/DISC control command frame,but send UA frame is error. Example: Gsmld receive dlc0 SABM frame "f9 03 3f 01 1c f9",now it sends UA frame "f9 01 63 01 a3 f9",CR and PF bit are 0,but it should be set 1 from requster to initiator. Kernel test log as follows: Before modify [ 271.732031] c1 gsmld_receive: 00000000: f9 03 3f 01 1c f9 [ 271.741719] c1 <-- 0) C: SABM(P) [ 271.749483] c1 gsmld_output: 00000000: f9 01 63 01 a3 f9 [ 271.758337] c1 --> 0) R: UA(F) After modify [ 261.233188] c0 gsmld_receive: 00000000: f9 03 3f 01 1c f9 [ 261.242767] c0 <-- 0) C: SABM(P) [ 261.250497] c0 gsmld_output: 00000000: f9 03 73 01 d7 f9 [ 261.259759] c0 --> 0) C: UA(P) Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com> Link: https://lore.kernel.org/r/1629461872-26965-3-git-send-email-zhenguo6858@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-14tty: n_gsm: Modify cr bit value when config requesterZhenguo Zhao
When n_gsm config "initiator=0",as requester,gsmld will receive dlci SABM and DISC control command frame,the CR bit value should be 1. If cr == 0,it will goto invalid,and it can't send UA response frame and open requster dlci. case SABM|PF: - if (cr == 0) + if (cr == 0) { + printk("gsm_queue invalid\n"); goto invalid; + } Example,gsmld receive dlc0 SABM command frame:f9 03 3f 01 1c f9 but gsmld goto invalid. Kernel test log: [ 101.794705] c0 gsmld_receive: 00000000: f9 03 3f 01 1c f9 [ 101.803341] c0 <-- 0) C: SABM(P) [ 101.811371] c0 gsm_queue invalid Signed-off-by: Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com> Link: https://lore.kernel.org/r/1629461872-26965-2-git-send-email-zhenguo6858@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-27tty: drop put_tty_driverJiri Slaby
put_tty_driver() is an alias for tty_driver_kref_put(). There is no need for two exported identical functions, therefore switch all users of old put_tty_driver() to new tty_driver_kref_put() and remove the former for good. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Scott Branden <scott.branden@broadcom.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Alex Elder <elder@kernel.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: NXP Linux Team <linux-imx@nxp.com> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Acked-by: Alex Elder <elder@linaro.org> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: David Sterba <dsterba@suse.com> Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210723074317.32690-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-27tty: stop using alloc_tty_driverJiri Slaby
alloc_tty_driver was deprecated by tty_alloc_driver in commit 7f0bc6a68ed9 (TTY: pass flags to alloc_tty_driver) in 2012. I never got into eliminating alloc_tty_driver until now. So we still have two functions for allocating drivers which might be confusing. So get rid of alloc_tty_driver uses to eliminate it for good in the next patch. Note we need to switch return value checking as tty_alloc_driver uses ERR_PTR. And flags are now a parameter of tty_alloc_driver. Cc: Richard Henderson <rth@twiddle.net>(odd fixer:ALPHA PORT) Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Johan Hovold <johan@kernel.org> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Acked-by: David Sterba <dsterba@suse.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210723074317.32690-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20tty: n_gsm: Fix function naming and provide missing param descriptionsLee Jones
Fixes the following W=1 kernel build warning(s): drivers/tty/n_gsm.c:525: warning: expecting prototype for gsm_stuff_packet(). Prototype was for gsm_stuff_frame() instead drivers/tty/n_gsm.c:1608: warning: expecting prototype for gsm_dlci_control(). Prototype was for gsm_dlci_command() instead drivers/tty/n_gsm.c:2561: warning: Function parameter or member 'cookie' not described in 'gsmld_read' drivers/tty/n_gsm.c:2561: warning: Function parameter or member 'offset' not described in 'gsmld_read' Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20210520121906.3468725-11-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: make tty_operations::chars_in_buffer return uintJiri Slaby
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 <jslaby@suse.cz> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Acked-by: David Sterba <dsterba@suse.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Alex Elder <elder@kernel.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Link: https://lore.kernel.org/r/20210505091928.22010-27-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: make tty_operations::write_room return uintJiri Slaby
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 <jslaby@suse.cz> Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com> Acked-by: Alex Elder <elder@linaro.org> Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa Acked-by: David Sterba <dsterba@suse.com> Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Chris Zankel <chris@zankel.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Cc: Jens Taprogge <jens.taprogge@taprogge.org> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Scott Branden <scott.branden@broadcom.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Lin <dtwlin@gmail.com> Cc: Johan Hovold <johan@kernel.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Oliver Neukum <oneukum@suse.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Mathias Nyman <mathias.nyman@intel.com> Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: no checking of tty_unregister_ldiscJiri Slaby
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 Slaby
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>
2021-05-13n_gsm: use goto-failpaths in gsm_initJiri Slaby
Use the classic failpath handling using gotos in gsm_init. That way, tty_unregister_ldisc needs not be repeated on two places. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210505091928.22010-16-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13tty: set tty_ldisc_ops::num staticallyJiri Slaby
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 Slaby
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-Hartman
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>
2021-04-15tty: n_gsm: check error while registering tty devicesHillf Danton
Add the error path for registering tty devices and roll back in case of error in bid to avoid the UAF like the below one reported. Plus syzbot reported general protection fault in cdev_del() on Sep 24, 2020 and both cases are down to the kobject_put() in tty_cdev_add(). ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 8923 at lib/refcount.c:28 refcount_warn_saturate+0x1cf/0x210 -origin/lib/refcount.c:28 Modules linked in: CPU: 1 PID: 8923 Comm: executor Not tainted 5.12.0-rc5+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:refcount_warn_saturate+0x1cf/0x210 -origin/lib/refcount.c:28 Code: 4f ff ff ff e8 32 fa b5 fe 48 c7 c7 3d f8 f6 86 e8 d6 ab c6 fe c6 05 7c 34 67 04 01 48 c7 c7 68 f8 6d 86 31 c0 e8 81 2e 9d fe <0f> 0b e9 22 ff ff ff e8 05 fa b5 fe 48 c7 c7 3e f8 f6 86 e8 a9 ab RSP: 0018:ffffc90001633c60 EFLAGS: 00010246 RAX: 15d08b2e34b77800 RBX: 0000000000000003 RCX: ffff88804c056c80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: ffffffff813767aa R09: 0001ffffffffffff R10: 0001ffffffffffff R11: ffff88804c056c80 R12: ffff888040b7d000 R13: ffff88804c206938 R14: ffff88804c206900 R15: ffff888041b18488 FS: 00000000022c9940(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9f9b122008 CR3: 0000000044b4b000 CR4: 0000000000750ee0 PKRU: 55555554 Call Trace: __refcount_sub_and_test -origin/./include/linux/refcount.h:283 [inline] __refcount_dec_and_test -origin/./include/linux/refcount.h:315 [inline] refcount_dec_and_test -origin/./include/linux/refcount.h:333 [inline] kref_put -origin/./include/linux/kref.h:64 [inline] kobject_put+0x17b/0x180 -origin/lib/kobject.c:753 cdev_del+0x4b/0x50 -origin/fs/char_dev.c:597 tty_unregister_device+0x99/0xd0 -origin/drivers/tty/tty_io.c:3343 gsmld_detach_gsm -origin/drivers/tty/n_gsm.c:2409 [inline] gsmld_close+0x6c/0x140 -origin/drivers/tty/n_gsm.c:2478 tty_ldisc_close -origin/drivers/tty/tty_ldisc.c:488 [inline] tty_ldisc_kill -origin/drivers/tty/tty_ldisc.c:636 [inline] tty_ldisc_release+0x1b6/0x400 -origin/drivers/tty/tty_ldisc.c:809 tty_release_struct+0x19/0xb0 -origin/drivers/tty/tty_io.c:1714 tty_release+0x9ad/0xa00 -origin/drivers/tty/tty_io.c:1885 __fput+0x260/0x4e0 -origin/fs/file_table.c:280 ____fput+0x11/0x20 -origin/fs/file_table.c:313 task_work_run+0x8e/0x110 -origin/kernel/task_work.c:140 tracehook_notify_resume -origin/./include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop -origin/kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x16b/0x1a0 -origin/kernel/entry/common.c:208 __syscall_exit_to_user_mode_work -origin/kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x20/0x40 -origin/kernel/entry/common.c:301 do_syscall_64+0x45/0x80 -origin/arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by: syzbot+c49fe6089f295a05e6f8@syzkaller.appspotmail.com Reported-and-tested-by: Hao Sun <sunhao.th@gmail.com> Signed-off-by: Hillf Danton <hdanton@sina.com> Link: https://lore.kernel.org/r/20210412035758.1974-1-hdanton@sina.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-07tty: n_gsm: use DEFINE_SPINLOCK() for spinlockGuobin Huang
spinlock can be initialized automatically with DEFINE_SPINLOCK() rather than explicitly calling spin_lock_init(). Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Guobin Huang <huangguobin4@huawei.com> Link: https://lore.kernel.org/r/1617710163-48158-1-git-send-email-huangguobin4@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10tty: make everyone's write_room return >= 0Jiri Slaby
The tty line disciplines don't expect tty_operations::write_room to return negative values. Fix the five drivers which violate this. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-44-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10tty: make everyone's chars_in_buffer return >= 0Jiri Slaby
The tty line disciplines don't expect tty_operations::chars_in_buffer to return negative values. Fix the two drivers which violate this. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-43-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10tty: n_gsm, remove duplicates of parametersJiri Slaby
dp, f, and i are only duplicates of gsmld_receive_buf's parameters. Use the parameters directly (cp, fp, and count) and delete these local variables. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-41-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10tty: remove TTY_LDISC_MAGICJiri Slaby
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>
2021-01-21Merge 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
2021-01-20tty: 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>
2020-11-06tty: n_gsm: Demote obvious abuse of kernel-doc and supply other missing docssLee Jones
Fixes the following W=1 kernel build warning(s): drivers/tty/n_gsm.c:85: warning: Function parameter or member 'ref' not described in 'gsm_mux_net' drivers/tty/n_gsm.c:85: warning: Function parameter or member 'dlci' not described in 'gsm_mux_net' drivers/tty/n_gsm.c:664: warning: Function parameter or member 'dlci' not described in 'gsm_data_kick' drivers/tty/n_gsm.c:1015: warning: Function parameter or member 'clen' not described in 'gsm_process_modem' Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20201104193549.4026187-19-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-31Merge 5.9-rc3 into tty-nextGreg Kroah-Hartman
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. Silva
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 Slaby
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>
2020-08-18tty: n_gsm, eliminate indirection for gsm->{output,error}()Jiri Slaby
gsm->output and ->error are set only to gsmld_output and gsm_error, respectively. Call these functions directly and remove error and output function pointers from struct gsm_mux completely. Note: we need a forward declaration of gsmld_output now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085655.12071-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-19tty: n_gsm: Fix bogus i++ in gsm_data_kickGregory CLEMENT
When submitting the previous fix "tty: n_gsm: Fix waking up upper tty layer when room available". It was suggested to switch from a while to a for loop, but when doing it, there was a remaining bogus i++. This patch removes this i++ and also reorganizes the code making it more compact. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> Link: https://lore.kernel.org/r/20200518084517.2173242-3-gregory.clement@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-19tty: n_gsm: Remove unnecessary test in gsm_print_packet()Gregory CLEMENT
If the length is zero then the print_hex_dump_bytes won't output anything, so testing the length before the call is unnecessary. Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> Link: https://lore.kernel.org/r/20200518084517.2173242-2-gregory.clement@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15tty: n_gsm: Fix waking up upper tty layer when room availableGregory CLEMENT
Warn the upper layer when n_gms is ready to receive data again. Without this the associated virtual tty remains blocked indefinitely. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> Link: https://lore.kernel.org/r/20200512115323.1447922-4-gregory.clement@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15tty: n_gsm: Fix SOF skippingGregory CLEMENT
For at least some modems like the TELIT LE910, skipping SOF makes transfers blocking indefinitely after a short amount of data transferred. Given the small improvement provided by skipping the SOF (just one byte on about 100 bytes), it seems better to completely remove this "feature" than make it optional. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> Link: https://lore.kernel.org/r/20200512115323.1447922-3-gregory.clement@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15tty: n_gsm: Improve debug outputGregory CLEMENT
Use appropriate print helpers for debug messages. Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> Link: https://lore.kernel.org/r/20200512115323.1447922-2-gregory.clement@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: switch escape to boolJiri Slaby
gsm_mux->escape is used as a bool, so treat it as such. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: switch constipated to boolJiri Slaby
Both gsm_dlci->constipated and gsm_mux->constipated are used as bools, so treat them as such. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: switch throttled to boolJiri Slaby
gsm_dlci->throttled is used as a bool, so treat it as such. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: switch dead to boolJiri Slaby
Both gsm_dlci->dead and gsm_mux->dead are used as bools, so treat them as such. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: add missing \n to printsJiri Slaby
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: add missing __user annotationsJiri Slaby
sparse warns about incorrect types: n_gsm.c:2638:35: warning: incorrect type in argument 1 (different address spaces) n_gsm.c:2638:35: expected void [noderef] <asn:1> *to n_gsm.c:2638:35: got void * The ioctl handler casts its `arg' to (void *) without __user. Add that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: introduce enum gsm_mux_stateJiri Slaby
gsm_mux->state is clearly an enumeration. So introduce one and use it -- compiler now checks if valid values are assigned to the field. Note that a compiler warns about unhandled cases in switch. Add default cases with a pr_debug (which is not printed by default). The values of the states are preserved thanks to the nature of enum. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-19n_gsm: introduce enum gsm_dlci_modeJiri Slaby
gsm_dlci->mode is clearly an enumeration. So introduce one and use it -- compiler now checks if valid values are assigned to the field. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219084949.28074-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>