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* serial: tegra-tcu: Use uart_xmit_advance(), fixes icount.tx accountingIlpo Järvinen2022-09-071-1/+1
| | | | | | | | | | | | Tx'ing does not correctly account Tx'ed characters into icount.tx. Using uart_xmit_advance() fixes the problem. Fixes: 2d908b38d409 ("serial: Add Tegra Combined UART driver") Cc: <stable@vger.kernel.org> # serial: Create uart_xmit_advance() Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220901143934.8850-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: tegra: Use uart_xmit_advance(), fixes icount.tx accountingIlpo Järvinen2022-09-071-3/+2
| | | | | | | | | | | | DMA complete & stop paths did not correctly account Tx'ed characters into icount.tx. Using uart_xmit_advance() fixes the problem. Fixes: e9ea096dd225 ("serial: tegra: add serial driver") Cc: <stable@vger.kernel.org> # serial: Create uart_xmit_advance() Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220901143934.8850-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: n_gsm: avoid call of sleeping functions from atomic contextFedor Pchelkin2022-08-301-29/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Syzkaller reports the following problem: BUG: sleeping function called from invalid context at kernel/printk/printk.c:2347 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1105, name: syz-executor423 3 locks held by syz-executor423/1105: #0: ffff8881468b9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x90 drivers/tty/tty_ldisc.c:266 #1: ffff8881468b9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:952 [inline] #1: ffff8881468b9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: do_tty_write drivers/tty/tty_io.c:975 [inline] #1: ffff8881468b9130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: file_tty_write.constprop.0+0x2a8/0x8e0 drivers/tty/tty_io.c:1118 #2: ffff88801b06c398 (&gsm->tx_lock){....}-{2:2}, at: gsmld_write+0x5e/0x150 drivers/tty/n_gsm.c:2717 irq event stamp: 3482 hardirqs last enabled at (3481): [<ffffffff81d13343>] __get_reqs_available+0x143/0x2f0 fs/aio.c:946 hardirqs last disabled at (3482): [<ffffffff87d39722>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (3482): [<ffffffff87d39722>] _raw_spin_lock_irqsave+0x52/0x60 kernel/locking/spinlock.c:159 softirqs last enabled at (3408): [<ffffffff87e01002>] asm_call_irq_on_stack+0x12/0x20 softirqs last disabled at (3401): [<ffffffff87e01002>] asm_call_irq_on_stack+0x12/0x20 Preemption disabled at: [<0000000000000000>] 0x0 CPU: 2 PID: 1105 Comm: syz-executor423 Not tainted 5.10.137-syzkaller #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 ___might_sleep.cold+0x1e8/0x22e kernel/sched/core.c:7304 console_lock+0x19/0x80 kernel/printk/printk.c:2347 do_con_write+0x113/0x1de0 drivers/tty/vt/vt.c:2909 con_write+0x22/0xc0 drivers/tty/vt/vt.c:3296 gsmld_write+0xd0/0x150 drivers/tty/n_gsm.c:2720 do_tty_write drivers/tty/tty_io.c:1028 [inline] file_tty_write.constprop.0+0x502/0x8e0 drivers/tty/tty_io.c:1118 call_write_iter include/linux/fs.h:1903 [inline] aio_write+0x355/0x7b0 fs/aio.c:1580 __io_submit_one fs/aio.c:1952 [inline] io_submit_one+0xf45/0x1a90 fs/aio.c:1999 __do_sys_io_submit fs/aio.c:2058 [inline] __se_sys_io_submit fs/aio.c:2028 [inline] __x64_sys_io_submit+0x18c/0x2f0 fs/aio.c:2028 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 The problem happens in the following control flow: gsmld_write(...) spin_lock_irqsave(&gsm->tx_lock, flags) // taken a spinlock on TX data con_write(...) do_con_write(...) console_lock() might_sleep() // -> bug As far as console_lock() might sleep it should not be called with spinlock held. The patch replaces tx_lock spinlock with mutex in order to avoid the problem. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 32dd59f96924 ("tty: n_gsm: fix race condition in gsmld_write()") Cc: stable <stable@kernel.org> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Link: https://lore.kernel.org/r/20220829131640.69254-3-pchelkin@ispras.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: n_gsm: replace kicktimer with delayed_workFedor Pchelkin2022-08-301-8/+8
| | | | | | | | | | | | | | | | | A kick_timer timer_list is replaced with kick_timeout delayed_work to be able to synchronize with mutexes as a prerequisite for the introduction of tx_mutex. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: c568f7086c6e ("tty: n_gsm: fix missing timer to handle stalled links") Cc: stable <stable@kernel.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Suggested-by: Hillf Danton <hdanton@sina.com> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Link: https://lore.kernel.org/r/20220829131640.69254-2-pchelkin@ispras.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: n_gsm: initialize more members at gsm_alloc_mux()Tetsuo Handa2022-08-301-11/+6
| | | | | | | | | | | | | | | | | | | | | syzbot is reporting use of uninitialized spinlock at gsmld_write() [1], for commit 32dd59f96924f45e ("tty: n_gsm: fix race condition in gsmld_write()") allows accessing gsm->tx_lock before gsm_activate_mux() initializes it. Since object initialization should be done right after allocation in order to avoid accessing uninitialized memory, move initialization of timer/work/waitqueue/spinlock from gsmld_open()/gsm_activate_mux() to gsm_alloc_mux(). Link: https://syzkaller.appspot.com/bug?extid=cf155def4e717db68a12 [1] Fixes: 32dd59f96924f45e ("tty: n_gsm: fix race condition in gsmld_write()") Reported-by: syzbot <syzbot+cf155def4e717db68a12@syzkaller.appspotmail.com> Tested-by: syzbot <syzbot+cf155def4e717db68a12@syzkaller.appspotmail.com> Cc: stable <stable@kernel.org> Acked-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: https://lore.kernel.org/r/2110618e-57f0-c1ce-b2ad-b6cacef3f60e@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf()Mazin Al Haddad2022-08-301-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A null pointer dereference can happen when attempting to access the "gsm->receive()" function in gsmld_receive_buf(). Currently, the code assumes that gsm->recieve is only called after MUX activation. Since the gsmld_receive_buf() function can be accessed without the need to initialize the MUX, the gsm->receive() function will not be set and a NULL pointer dereference will occur. Fix this by avoiding the call to "gsm->receive()" in case the function is not initialized by adding a sanity check. Call Trace: <TASK> gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861 tiocsti drivers/tty/tty_io.c:2293 [inline] tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Link: https://syzkaller.appspot.com/bug?id=bdf035c61447f8c6e0e6920315d577cb5cc35ac5 Fixes: 01aecd917114 ("tty: n_gsm: fix tty registration before control channel open") Cc: stable <stable@kernel.org> Reported-and-tested-by: syzbot+e3563f0c94e188366dbb@syzkaller.appspotmail.com Signed-off-by: Mazin Al Haddad <mazinalhaddad05@gmail.com> Link: https://lore.kernel.org/r/20220814015211.84180-1-mazinalhaddad05@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: atmel: Preserve previous USART mode if RS485 disabledSergiu Moga2022-08-301-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Whenever the atmel_rs485_config() driver method would be called, the USART mode is reset to normal mode before even checking if RS485 flag is set, thus resulting in losing the previous USART mode in the case where the checking fails. Some tools, such as `linux-serial-test`, lead to the driver calling this method when doing the setup of the serial port: after setting the port mode (Hardware Flow Control, Normal Mode, RS485 Mode, etc.), `linux-serial-test` tries to enable/disable RS485 depending on the commandline arguments that were passed. Example of how this issue could reveal itself: When doing a serial communication with Hardware Flow Control through `linux-serial-test`, the tool would lead to the driver roughly doing the following: - set the corresponding bit to 1 (ATMEL_US_USMODE_HWHS bit in the ATMEL_US_MR register) through the atmel_set_termios() to enable Hardware Flow Control - disable RS485 through the atmel_config_rs485() method Thus, when the latter is called, the mode will be reset and the previously set bit is unset, leaving USART in normal mode instead of the expected Hardware Flow Control mode. This fix ensures that this reset is only done if the checking for RS485 succeeds and that the previous mode is preserved otherwise. Fixes: e8faff7330a35 ("ARM: 6092/1: atmel_serial: support for RS485 communications") Cc: stable <stable@kernel.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com> Link: https://lore.kernel.org/r/20220824142902.502596-1-sergiu.moga@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: serial: lpuart: disable flow control while waiting for the transmit ↵Sherry Sun2022-08-301-0/+1
| | | | | | | | | | | | | | | | engine to complete When the user initializes the uart port, and waits for the transmit engine to complete in lpuart32_set_termios(), if the UART TX fifo has dirty data and the UARTMODIR enable the flow control, the TX fifo may never be empty. So here we should disable the flow control first to make sure the transmit engin can complete. Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support") Cc: stable <stable@kernel.org> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20220821101527.10066-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Fix lookahead_buf crash with serdevVincent Whitchurch2022-08-301-5/+9
| | | | | | | | | | | | | Do not follow a NULL pointer if the tty_port_client_operations does not implement the ->lookahead_buf() callback, which is the case with serdev's ttyport. Reported-by: Hans de Goede <hdegoede@redhat.com> Fixes: 6bb6fa6908ebd3 ("tty: Implement lookahead to process XON/XOFF timely") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Link: https://lore.kernel.org/r/20220818115026.2237893-1-vincent.whitchurch@axis.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* serial: fsl_lpuart: RS485 RTS polariy is inverseShenwei Wang2022-08-301-2/+2
| | | | | | | | | | | | | | | The setting of RS485 RTS polarity is inverse in the current driver. When the property of 'rs485-rts-active-low' is enabled in the dts node, the RTS signal should be LOW during sending. Otherwise, if there is no such a property, the RTS should be HIGH during sending. Fixes: 03895cf41d18 ("tty: serial: fsl_lpuart: Add support for RS-485") Cc: stable <stable@kernel.org> Signed-off-by: Nicolas Diaz <nicolas.diaz@nxp.com> Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com> Link: https://lore.kernel.org/r/20220805144529.604856-1-shenwei.wang@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vt: Clear selection before changing the fontHelge Deller2022-08-301-4/+8
| | | | | | | | | | | | | | | | | | When changing the console font with ioctl(KDFONTOP) the new font size can be bigger than the previous font. A previous selection may thus now be outside of the new screen size and thus trigger out-of-bounds accesses to graphics memory if the selection is removed in vc_do_resize(). Prevent such out-of-memory accesses by dropping the selection before the various con_font_set() console handlers are called. Reported-by: syzbot+14b0e8f3fd1612e35350@syzkaller.appspotmail.com Cc: stable <stable@kernel.org> Tested-by: Khalid Masum <khalid.masum.92@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Link: https://lore.kernel.org/r/YuV9apZGNmGfjcor@p100 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'tty-6.0-rc1' of ↵Linus Torvalds2022-08-0867-2584/+2706
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 and serial driver changes for 6.0-rc1. It was delayed from last week as I wanted to make sure the last commit here got some good testing in linux-next and elsewhere as it seemed to show up only late in testing for some reason. Nothing major here, just lots of cleanups from Jiri and Ilpo to make the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo). Also included in here is the obligatory n_gsm updates from Daniel Starke and lots of tiny driver updates and minor fixes and tweaks for other smaller serial drivers. All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits) tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements tty: amiserial: Fix comment typo tty: serial: document uart_get_console() tty: serial: serial_core, reformat kernel-doc for functions Documentation: serial: link uart_ops properly Documentation: serial: move GPIO kernel-doc to the functions Documentation: serial: dedup kernel-doc for uart functions Documentation: serial: move uart_ops documentation to the struct dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126 serial: mvebu-uart: uart2 error bits clearing tty: serial: fsl_lpuart: correct the count of break characters serial: stm32: make info structs static to avoid sparse warnings serial: fsl_lpuart: zero out parity bit in CS7 mode tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate. serial: 8250_bcm2835aux: Add missing clk_disable_unprepare() tty: vt: initialize unicode screen buffer serial: remove VR41XX serial driver serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags serial: 8250_dwlib: remove redundant sanity check for RS485 flags dt_bindings: rs485: Correct delay values ...
| * tty: serial: qcom-geni-serial: Fix %lu -> %u in print statementsDouglas Anderson2022-08-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we multiply an unsigned int by a u32 we still end up with an unsigned int. That means we should specify "%u" not "%lu" in the format code. NOTE: this fix was chosen instead of somehow promoting the value to "unsigned long" since the max baud rate from the earlier call to uart_get_baud_rate() is 4000000 and the max sampling rate is 32. 4000000 * 32 = 0x07a12000, not even close to overflowing 32-bits. Fixes: c474c775716e ("tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.") Reported-by: Mark Brown <broonie@kernel.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20220802132250.1.Iea061e14157a17e114dbe2eca764568a02d6b889@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: amiserial: Fix comment typoJason Wang2022-07-281-1/+1
| | | | | | | | | | | | | | | | The double `should' is duplicated in line 15, remove one. Signed-off-by: Jason Wang <wangborong@cdjrlc.com> Link: https://lore.kernel.org/r/20220715054401.9870-1-wangborong@cdjrlc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: serial: document uart_get_console()Jiri Slaby2022-07-281-4/+9
| | | | | | | | | | | | | | | | | | | | This was the only function mentioned in the text, but was neither linked nor documented. So document and link it, so that hyperlinking works in the text. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: serial: serial_core, reformat kernel-doc for functionsJiri Slaby2022-07-281-54/+53
| | | | | | | | | | | | | | | | | | | | There are many annotated functions in serial_core.c, but they do not completely conform to the kernel-doc style. So reformat them and link them from the Documentation. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Documentation: serial: move GPIO kernel-doc to the functionsJiri Slaby2022-07-281-0/+48
| | | | | | | | | | | | | | | | | | | | | | | | The GPIO uart functions are documented in Documentation. Move and transform this documentation into kernel-doc directly in the code and reference it in Documentation using kernel-doc:. This makes it easier to update, maintain and check by the build. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Documentation: serial: dedup kernel-doc for uart functionsJiri Slaby2022-07-281-59/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of the serial (uart_*) functions are documented twice. Once as kernel-doc along their sources and once in Documentation. So deduplicate these texts, merge them into kernel-doc in the sources, and link them using kernel-doc: from the Documentation. To be properly linked and rendered, tabulators had to be removed from the comments. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220728061056.20799-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: mvebu-uart: uart2 error bits clearingNarendra Hadke2022-07-281-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | For mvebu uart2, error bits are not cleared on buffer read. This causes interrupt loop and system hang. Cc: stable@vger.kernel.org Reviewed-by: Yi Guo <yi.guo@cavium.com> Reviewed-by: Nadav Haklai <nadavh@marvell.com> Signed-off-by: Narendra Hadke <nhadke@marvell.com> Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20220726091221.12358-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: serial: fsl_lpuart: correct the count of break charactersSherry Sun2022-07-281-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | The LPUART can't distinguish between a break signal and a framing error, so need to count the break characters if there is a framing error and received data is zero instead of the parity error. Fixes: 5541a9bacfe5 ("serial: fsl_lpuart: handle break and make sysrq work") Reviewed-by: Michael Walle <michael@walle.cc> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20220725050115.12396-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: stm32: make info structs static to avoid sparse warningsBen Dooks2022-07-282-68/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The info structs are local only to the stm32-usart.c driver and are triggering sparse warnings about being undecalred. Move these into the main driver code and make them static to avoid the following warnings: drivers/tty/serial/stm32-usart.h:42:25: warning: symbol 'stm32f4_info' was not declared. Should it be static? drivers/tty/serial/stm32-usart.h:63:25: warning: symbol 'stm32f7_info' was not declared. Should it be static? drivers/tty/serial/stm32-usart.h:85:25: warning: symbol 'stm32h7_info' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben-linux@fluff.org> Link: https://lore.kernel.org/r/20220721212430.453192-1-ben-linux@fluff.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: fsl_lpuart: zero out parity bit in CS7 modeShenwei Wang2022-07-281-2/+24
| | | | | | | | | | | | | | | | | | | | | | | | The LPUART hardware doesn't zero out the parity bit on the received characters. This behavior won't impact the use cases of CS8 because the parity bit is the 9th bit which is not currently used by software. But the parity bit for CS7 must be zeroed out by software in order to get the correct raw data. Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com> Link: https://lore.kernel.org/r/20220714185858.615373-1-shenwei.wang@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could ↵Vijaya Krishna Nivarthi2022-07-281-35/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | return a sub-optimal clock rate. In the logic around call to clk_round_rate(), for some corner conditions, get_clk_div_rate() could return an sub-optimal clock rate. Also, if an exact clock rate was not found lowest clock was being returned. Search for suitable clock rate in 2 steps a) exact match or within 2% tolerance b) within 5% tolerance This also takes care of corner conditions. Fixes: c2194bc999d4 ("tty: serial: qcom-geni-serial: Remove uart frequency table. Instead, find suitable frequency with call to clk_round_rate") Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com> Link: https://lore.kernel.org/r/1657911343-1909-1-git-send-email-quic_vnivarth@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: 8250_bcm2835aux: Add missing clk_disable_unprepare()Guo Mengqi2022-07-281-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The error path when get clock frequency fails in bcm2835aux_serial driver does not correctly disable the clock. This flaw was found using a static analysis tool "Hulk Robot", which reported the following warning when analyzing linux-next/master: drivers/tty/serial/8250/8250_bcm2835aux.c: warning: clk_disable_unprepare_missing.cocci The cocci script checks for the existence of clk_disable_unprepare() paired with clk_prepare_enable(). Add the missing clk_disable_unprepare() to the error path. Fixes: fcc446c8aa63 ("serial: 8250_bcm2835aux: Add ACPI support") Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Guo Mengqi <guomengqi3@huawei.com> Link: https://lore.kernel.org/r/20220715023312.37808-1-guomengqi3@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: vt: initialize unicode screen bufferTetsuo Handa2022-07-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot reports kernel infoleak at vcs_read() [1], for buffer can be read immediately after resize operation. Initialize buffer using kzalloc(). ---------- #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/fb.h> int main(int argc, char *argv[]) { struct fb_var_screeninfo var = { }; const int fb_fd = open("/dev/fb0", 3); ioctl(fb_fd, FBIOGET_VSCREENINFO, &var); var.yres = 0x21; ioctl(fb_fd, FBIOPUT_VSCREENINFO, &var); return read(open("/dev/vcsu", O_RDONLY), &var, sizeof(var)) == -1; } ---------- Link: https://syzkaller.appspot.com/bug?extid=31a641689d43387f05d3 [1] Cc: stable <stable@vger.kernel.org> Reported-by: syzbot <syzbot+31a641689d43387f05d3@syzkaller.appspotmail.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: https://lore.kernel.org/r/4ef053cf-e796-fb5e-58b7-3ae58242a4ad@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: remove VR41XX serial driverThomas Bogendoerfer2022-07-163-950/+0
| | | | | | | | | | | | | | | | | | | | Commit d3164e2f3b0a ("MIPS: Remove VR41xx support") removed support for MIPS VR41xx platform, so remove exclusive drivers for this platform, too. Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Link: https://lore.kernel.org/r/20220715140322.135825-1-tsbogend@alpha.franken.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flagsLino Sanfilippo2022-07-141-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | Before the drivers rs485_config() function is called the serial core already ensures that only one of both options RTS on send or RTS after send is set. So remove the concerning sanity check in the driver function to avoid redundancy. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-9-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: 8250_dwlib: remove redundant sanity check for RS485 flagsLino Sanfilippo2022-07-141-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | Before the drivers rs485_config() function is called the serial core already ensures that only one of both options RTS on send or RTS after send is set. So remove the concerning sanity check in the driver function to avoid redundancy. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-8-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: core: sanitize RS485 delays read from device treeLino Sanfilippo2022-07-141-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the RTS delays set via device tree are not clamped to a maximum value although the device tree bindings documentation for RS485 claims that only a maximum of 1000 msecs is allowed. So clamp the values to avoid arbitrary high delay settings. However clamp the values to 100 instead of 1000 msecs to be consistent which the maximum that is allowed when setting the delays from userspace via the UART ioctl TIOCSRS485. Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-6-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: core: move sanitizing of RS485 delays into own functionLino Sanfilippo2022-07-141-20/+26
| | | | | | | | | | | | | | | | | | | | Move the sanitizing of RS485 delays out of uart_sanitize_serial_rs485() into the new function uart_sanitize_serial_rs485_delays(). Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-5-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: core, 8250: set RS485 termination GPIO in serial coreLino Sanfilippo2022-07-142-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In serial8250_em485_config() the termination GPIO is set with the uart_port spinlock held. This is an issue if setting the GPIO line can sleep (e.g. since the concerning GPIO expander is connected via SPI or I2C). Fix this by setting the termination line outside of the uart_port spinlock in the serial core and using gpiod_set_value_cansleep() which instead of gpiod_set_value() allows it to sleep. Beside fixing the termination GPIO line setting for the 8250 driver this change also makes setting the termination GPIO generic for all UART drivers. Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-4-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: ar933x: Remove superfluous code in ar933x_config_rs485()Lino Sanfilippo2022-07-141-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In ar933x_config_rs485() the check for the RTS GPIO is not needed since in case the GPIO is not available at driver init ar933x_no_rs485 is assigned to port->rs485_supported and this function is never called. So remove the check. Also in uart_set_rs485_config() the serial core already assigns the passed serial_rs485 struct to the uart port. So remove the assignment in the drivers rs485_config() function to avoid redundancy. Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-3-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: ar933x: Fix check for RS485 supportLino Sanfilippo2022-07-141-4/+5
| | | | | | | | | | | | | | | | | | | | | | RS485 is not possible without an RTS GPIO regardless of whether RS485 is enabled at boot time or not. So correct the concerning check in the probe() function. Fixes: e849145e1fdd ("serial: ar933x: Fill in rs485_supported") Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20220710164442.2958979-2-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: 8250_bcm7271: Save/restore RTS in suspend/resumeDoug Berger2022-07-141-6/+18
| | | | | | | | | | | | | | | | | | | | | | | | Commit 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming from S2") prevented an early enabling of RTS during resume, but it did not actively restore the RTS state after resume. Fixes: 9cabe26e65a8 ("serial: 8250_bcm7271: UART errors after resuming from S2") Signed-off-by: Doug Berger <opendmb@gmail.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20220714031316.404918-1-f.fainelli@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: 8250_dw: Avoid pslverr on reading empty receiver fifoVAMSHI GAJJELA2022-07-141-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With PSLVERR_RESP_EN parameter set to 1, the device generates an error response when an attempt to read an empty RBR with FIFO enabled. This happens when LCR writes are ignored when UART is busy. dw8250_check_lcr() in retries to update LCR, invokes dw8250_force_idle() to clear and reset FIFO and eventually reads UART_RX causing the error. Avoid this by not reading RBR/UART_RX when no data is available. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: VAMSHI GAJJELA <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20220713131722.2316829-1-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: serial: samsung_tty: fix s3c24xx_serial_set_mctrl()Marek Szyprowski2022-07-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | S3C2410_UCON is a 32bit register, so it must be read with rd_regl() instead of rd_reg(), otherwise the upper bits will be zeroed. Fix this. Fixes: 72a43046b61a ("tty: serial: samsung_tty: loopback mode support") Tested-by: Chanho Park <chanho61.park@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20220712140745.30362-1-m.szyprowski@samsung.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: 8250: SERIAL_8250_ASPEED_VUART should depend on ARCH_ASPEEDGeert Uytterhoeven2022-07-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | The Aspeed Virtual UART is only present on Aspeed BMC platforms. Hence add a dependency on ARCH_ASPEED, to prevent asking the user about this driver when configuring a kernel without Aspeed BMC support. Reviewed-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/259138c372d433005b4871789ef9ee8d15320307.1657528861.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: 8250: Add support for Brainboxes PX cards.Cameron Williams2022-07-141-0/+109
| | | | | | | | | | | | | | | | | | | | | | | | | | Add support for some of the Brainboxes PCIe (PX) range of serial cards, including the PX-101, PX-235/PX-246, PX-203/PX-257, PX-260/PX-701, PX-310, PX-313, PX-320/PX-324/PX-376/PX-387, PX-335/PX-346, PX-368, PX-420, PX-803 and PX-846. Signed-off-by: Cameron Williams <cang1@live.co.uk> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/AM5PR0202MB2564669252BDC59BF55A6E87C4879@AM5PR0202MB2564.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix missing corner cases in gsmld_poll()Daniel Starke2022-07-081-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | gsmld_poll() currently fails to handle the following corner cases correctly: - remote party closed the associated tty Add the missing checks and map those to EPOLLHUP. Reorder the checks to group them by their reaction. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix flow control handling in tx pathDaniel Starke2022-07-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation constipates all transmission paths during flow control except for flow control frames. However, these may not be located at the beginning of the transmission queue of the control channel. Ensure that flow control frames in the transmission queue for the control channel are always handled even if constipated by skipping through other messages. Fixes: 0af021678d5d ("tty: n_gsm: fix deadlock and link starvation in outgoing data path") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220707113223.3685-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix DM commandDaniel Starke2022-07-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 5.3.3 defines the DM response. There exists no DM command. However, the current implementation incorrectly sends DM as command in case of unexpected UIH frames in gsm_queue(). Correct this behavior by always sending DM as response. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220707113223.3685-2-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix wrong T1 retry count handlingDaniel Starke2022-07-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 5.7.3 states that the valid range for the maximum number of retransmissions (N2) is from 0 to 255 (both including). gsm_dlci_t1() handles this number incorrectly by performing N2 - 1 retransmission attempts. Setting N2 to zero results in more than 255 retransmission attempts. Fix gsm_dlci_t1() to comply with 3GPP 27.010. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220707113223.3685-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: RS485 termination is supported if DT provides oneIlpo Järvinen2022-07-081-0/+2
| | | | | | | | | | | | | | | | | | When DT provides rs485-term, set termination flag as supported. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: Embed rs485_supported to uart_portIlpo Järvinen2022-07-0818-26/+26
| | | | | | | | | | | | | | | | | | | | Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * serial: 8250_fsl: Don't report FE, PE and OE twiceUwe Kleine-König2022-07-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some Freescale 8250 implementations have the problem that a single long break results in one irq per character frame time. The code in fsl8250_handle_irq() that is supposed to handle that uses the BI bit in lsr_saved_flags to detect such a situation and then skip the second received character. However it also stores other error bits and so after a single frame error the character received in the next irq handling is passed to the upper layer with a frame error, too. So after a spike on the data line (which is correctly recognized as a frame error) the following valid character is thrown away, because the driver reports a frame error for that one, too. To weaken this problem restrict saving LSR to only the BI bit. Note however that the handling is still broken: - lsr_saved_flags is updated using orig_lsr which is the LSR content for the first received char, but there might be more in the FIFO, so a character is thrown away that is received later and not necessarily the one following the break. - The doubled break might be the 2nd and 3rd char in the FIFO, so the workaround doesn't catch these, because serial8250_rx_chars() doesn't handle the workaround. - lsr_saved_flags might have set UART_LSR_BI at the entry of fsl8250_handle_irq() which doesn't originate from fsl8250_handle_irq()'s "up->lsr_saved_flags |= orig_lsr & UART_LSR_BI;" but from e.g. from serial8250_tx_empty(). - For a long or a short break this isn't about two characters, but more or only a single one. Fixes: 9deaa53ac7fa ("serial: add irq handler for Freescale 16550 errata.") Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220704085119.55900-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix resource allocation order in gsm_activate_mux()Daniel Starke2022-07-011-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | Within gsm_activate_mux() all timers and locks are initiated before the actual resource for the control channel is allocated. This can lead to race conditions. Allocate the control channel DLCI object first to avoid race conditions. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220701122332.2039-2-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix deadlock and link starvation in outgoing data pathDaniel Starke2022-07-011-128/+279
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation queues up new control and user packets as needed and processes this queue down to the ldisc in the same code path. That means that the upper and the lower layer are hard coupled in the code. Due to this deadlocks can happen as seen below while transmitting data, especially during ldisc congestion. Furthermore, the data channels starve the control channel on high transmission load on the ldisc. Introduce an additional control channel data queue to prevent timeouts and link hangups during ldisc congestion. This is being processed before the user channel data queue in gsm_data_kick(), i.e. with the highest priority. Put the queue to ldisc data path into a workqueue and trigger it whenever new data has been put into the transmission queue. Change gsm_dlci_data_sweep() accordingly to fill up the transmission queue until TX_THRESH_HI. This solves the locking issue, keeps latency low and provides good performance on high data load. Note that now all packets from a DLCI are removed from the internal queue if the associated DLCI was closed. This ensures that no data is sent by the introduced write task to an already closed DLCI. BUG: spinlock recursion on CPU#0, test_v24_loop/124 lock: serial8250_ports+0x3a8/0x7500, .magic: dead4ead, .owner: test_v24_loop/124, .owner_cpu: 0 CPU: 0 PID: 124 Comm: test_v24_loop Tainted: G O 5.18.0-rc2 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x34/0x44 do_raw_spin_lock+0x76/0xa0 _raw_spin_lock_irqsave+0x72/0x80 uart_write_room+0x3b/0xc0 gsm_data_kick+0x14b/0x240 [n_gsm] gsmld_write_wakeup+0x35/0x70 [n_gsm] tty_wakeup+0x53/0x60 tty_port_default_wakeup+0x1b/0x30 serial8250_tx_chars+0x12f/0x220 serial8250_handle_irq.part.0+0xfe/0x150 serial8250_default_handle_irq+0x48/0x80 serial8250_interrupt+0x56/0xa0 __handle_irq_event_percpu+0x78/0x1f0 handle_irq_event+0x34/0x70 handle_fasteoi_irq+0x90/0x1e0 __common_interrupt+0x69/0x100 common_interrupt+0x48/0xc0 asm_common_interrupt+0x1e/0x40 RIP: 0010:__do_softirq+0x83/0x34e Code: 2a 0a ff 0f b7 ed c7 44 24 10 0a 00 00 00 48 c7 c7 51 2a 64 82 e8 2d e2 d5 ff 65 66 c7 05 83 af 1e 7e 00 00 fb b8 ff ff ff ff <49> c7 c2 40 61 80 82 0f bc c5 41 89 c4 41 83 c4 01 0f 84 e6 00 00 RSP: 0018:ffffc90000003f98 EFLAGS: 00000286 RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff82642a51 RDI: ffffffff825bb5e7 RBP: 0000000000000200 R08: 00000008de3271a8 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000030 R14: 0000000000000000 R15: 0000000000000000 ? __do_softirq+0x73/0x34e irq_exit_rcu+0xb5/0x100 common_interrupt+0xa4/0xc0 </IRQ> <TASK> asm_common_interrupt+0x1e/0x40 RIP: 0010:_raw_spin_unlock_irqrestore+0x2e/0x50 Code: 00 55 48 89 fd 48 83 c7 18 53 48 89 f3 48 8b 74 24 10 e8 85 28 36 ff 48 89 ef e8 cd 58 36 ff 80 e7 02 74 01 fb bf 01 00 00 00 <e8> 3d 97 33 ff 65 8b 05 96 23 2b 7e 85 c0 74 03 5b 5d c3 0f 1f 44 RSP: 0018:ffffc9000020fd08 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000246 RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffffffff8257fd74 RDI: 0000000000000001 RBP: ffff8880057de3a0 R08: 00000008de233000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000100 R14: 0000000000000202 R15: ffff8880057df0b8 ? _raw_spin_unlock_irqrestore+0x23/0x50 gsmtty_write+0x65/0x80 [n_gsm] n_tty_write+0x33f/0x530 ? swake_up_all+0xe0/0xe0 file_tty_write.constprop.0+0x1b1/0x320 ? n_tty_flush_buffer+0xb0/0xb0 new_sync_write+0x10c/0x190 vfs_write+0x282/0x310 ksys_write+0x68/0xe0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f3e5e35c15c Code: 8b 7c 24 08 89 c5 e8 c5 ff ff ff 89 ef 89 44 24 08 e8 58 bc 02 00 8b 44 24 08 48 83 c4 10 5d c3 48 63 ff b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 fd fc 05 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffcee77cd18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffcee77cd70 RCX: 00007f3e5e35c15c RDX: 0000000000000100 RSI: 00007ffcee77cd90 RDI: 0000000000000003 RBP: 0000000000000100 R08: 0000000000000000 R09: 7efefefefefefeff R10: 00007f3e5e3bddeb R11: 0000000000000246 R12: 00007ffcee77ce8f R13: 0000000000000001 R14: 000056214404e010 R15: 00007ffcee77cd90 </TASK> Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220701122332.2039-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix race condition in gsmld_write()Daniel Starke2022-07-011-4/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function may be used by the user directly and also by the n_gsm internal functions. They can lead into a race condition which results in interleaved frames if both are writing at the same time. The receiving side is not able to decode those interleaved frames correctly. Add a lock around the low side tty write to avoid race conditions and frame interleaving between user originated writes and n_gsm writes. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220701061652.39604-9-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix packet re-transmission without open control channelDaniel Starke2022-07-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | In the current implementation control packets are re-transmitted even if the control channel closed down during T2. This is wrong. Check whether the control channel is open before re-transmitting any packets. Note that control channel open/close is handled by T1 and not T2 and remains unaffected by this. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220701061652.39604-7-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * tty: n_gsm: fix non flow control frames during mux flow offDaniel Starke2022-07-011-1/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 5.4.6.3.6 states that FCoff stops the transmission on all channels except the control channel. This is already implemented in gsm_data_kick(). However, chapter 5.4.8.1 explains that this shall result in the same behavior as software flow control on the ldisc in advanced option mode. That means only flow control frames shall be sent during flow off. The current implementation does not consider this case. Change gsm_data_kick() to send only flow control frames if constipated to abide the standard. gsm_read_ea_val() and gsm_is_flow_ctrl_msg() are introduced as helper functions for this. It is planned to use gsm_read_ea_val() in later code cleanups for other functions, too. Fixes: c01af4fec2c8 ("n_gsm : Flow control handling in Mux driver") Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20220701061652.39604-5-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>