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2018-12-17tty: serial: samsung: Properly set flags in autoCTS modeBeomho Seo
Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support") has changed the way the autoCTS mode is handled. According to that change, serial drivers which enable H/W autoCTS mode must set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling TX. This patch adds proper handling of UPSTAT_AUTOCTS flag. Signed-off-by: Beomho Seo <beomho.seo@samsung.com> [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty: Use of_node_name_{eq,prefix} for node name comparisonsRob Herring
Convert string compares of DT node names to use of_node_name_eq helper instead. This removes direct access to the node name pointer. For hvc, the code can also be simplified by using of_stdout pointer instead of searching again for the stdout node. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-serial@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty/serial: do not free trasnmit buffer page under port lockSergey Senozhatsky
LKP has hit yet another circular locking dependency between uart console drivers and debugobjects [1]: CPU0 CPU1 rhltable_init() __init_work() debug_object_init uart_shutdown() /* db->lock */ /* uart_port->lock */ debug_print_object() free_page() printk() call_console_drivers() debug_check_no_obj_freed() /* uart_port->lock */ /* db->lock */ debug_print_object() So there are two dependency chains: uart_port->lock -> db->lock And db->lock -> uart_port->lock This particular circular locking dependency can be addressed in several ways: a) One way would be to move debug_print_object() out of db->lock scope and, thus, break the db->lock -> uart_port->lock chain. b) Another one would be to free() transmit buffer page out of db->lock in UART code; which is what this patch does. It makes sense to apply a) and b) independently: there are too many things going on behind free(), none of which depend on uart_port->lock. The patch fixes transmit buffer page free() in uart_shutdown() and, additionally, in uart_port_startup() (as was suggested by Dmitry Safonov). [1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Waiman Long <longman@redhat.com> Cc: Dmitry Safonov <dima@arista.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: 8250: Rate limit serial port rx interrupts during input overrunsDarwin Dingel
When a serial port gets faulty or gets flooded with inputs, its interrupt handler starts to work double time to get the characters to the workqueue for the tty layer to handle them. When this busy time on the serial/tty subsystem happens during boot, where it is also busy on the userspace trying to initialise, some processes can continuously get preempted and will be on hold until the interrupts subside. The fix is to backoff on processing received characters for a specified amount of time when an input overrun is seen (received a new character before the previous one is processed). This only stops receive and will continue to transmit characters to serial port. After the backoff period is done, it receive will be re-enabled. This is optional and will only be enabled by setting 'overrun-throttle-ms' in the dts. Signed-off-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tty: serial: qcom_geni_serial: Remove interrupt stormRyan Case
Disable M_TX_FIFO_WATERMARK_EN after we've sent all data for a given transaction so we don't continue to receive a flurry of free space interrupts while waiting for the M_CMD_DONE notification. Re-enable the watermark when establishing the next transaction. Also clear the watermark interrupt after filling the FIFO so we do not receive notification again prior to actually having free space. Signed-off-by: Ryan Case <ryandcase@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failureGeert Uytterhoeven
On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler. Hence if DMA submission fails, the interrupt handler should resume handling reception using PIO, else no more data is received. Make sci_submit_rx() return an error indicator, so the receive interrupt handler can act appropriately. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallbackGeert Uytterhoeven
When falling back to PIO, active_rx must be set to a different value than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a match, leading to a NULL pointer dereference in rx_timer_fn() later. Use zero instead, which is the same value as after driver initialization. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17serial: sh-sci: Fix locking in sci_submit_rx()Geert Uytterhoeven
Some callers of sci_submit_rx() hold the port spinlock, others don't. During fallback to PIO, the driver needs to obtain the port spinlock. If the lock was already held, spinlock recursion is detected, causing a deadlock: BUG: spinlock recursion on CPU#0. Fix this by adding a flag parameter to sci_submit_rx() for the caller to indicate the port spinlock is already held, so spinlock recursion can be avoided. Move the spin_lock_irqsave() up, so all DMA disable steps are protected, which is safe as the recently introduced dmaengine_terminate_async() can be called in atomic context. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-10Merge 4.20-rc6 into tty-nextGreg Kroah-Hartman
We want the TTY changes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-09Merge tag 'tty-4.20-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty driver fixes from Greg KH: "Here are three small tty driver fixes for 4.20-rc6 Nothing major, just some bug fixes for reported issues. Full details are in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'tty-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var() tty: serial: 8250_mtk: always resume the device in probe. tty: do not set TTY_IO_ERROR flag if console port
2018-12-09Merge tag 'usb-4.20-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB fixes from Greg KH: "Here are some small USB fixes for 4.20-rc6 The "largest" here are some xhci fixes for reported issues. Also here is a USB core fix, some quirk additions, and a usb-serial fix which required the export of one of the tty layer's functions to prevent code duplication. The tty maintainer agreed with this change. All of these have been in linux-next with no reported issues" * tag 'usb-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: xhci: Prevent U1/U2 link pm states if exit latency is too long xhci: workaround CSS timeout on AMD SNPS 3.0 xHC USB: check usb_get_extra_descriptor for proper size USB: serial: console: fix reported terminal settings usb: quirk: add no-LPM quirk on SanDisk Ultra Flair device USB: Fix invalid-free bug in port_over_current_notify() usb: appledisplay: Add 27" Apple Cinema Display
2018-12-06kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()Macpaul Lin
This patch is trying to fix KE issue due to "BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198" reported by Syzkaller scan." [26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198 [26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364 [26364:syz-executor0][name:report&] [26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0 [26364:syz-executor0]Call trace: [26364:syz-executor0][<ffffff9008095cf8>] dump_bacIctrace+Ox0/0x470 [26364:syz-executor0][<ffffff9008096de0>] show_stack+0x20/0x30 [26364:syz-executor0][<ffffff90089cc9c8>] dump_stack+Oxd8/0x128 [26364:syz-executor0][<ffffff90084edb38>] print_address_description +0x80/0x4a8 [26364:syz-executor0][<ffffff90084ee270>] kasan_report+Ox178/0x390 [26364:syz-executor0][<ffffff90084ee4a0>] _asan_report_loadi_noabort+Ox18/0x20 [26364:syz-executor0][<ffffff9008b092ac>] param_set_kgdboc_var+Ox194/0x198 [26364:syz-executor0][<ffffff900813af64>] param_attr_store+Ox14c/0x270 [26364:syz-executor0][<ffffff90081394c8>] module_attr_store+0x60/0x90 [26364:syz-executor0][<ffffff90086690c0>] sysfs_kl_write+Ox100/0x158 [26364:syz-executor0][<ffffff9008666d84>] kernfs_fop_write+0x27c/0x3a8 [26364:syz-executor0][<ffffff9008508264>] do_loop_readv_writev+0x114/0x1b0 [26364:syz-executor0][<ffffff9008509ac8>] do_readv_writev+0x4f8/0x5e0 [26364:syz-executor0][<ffffff9008509ce4>] vfs_writev+0x7c/Oxb8 [26364:syz-executor0][<ffffff900850ba64>] SyS_writev+Oxcc/0x208 [26364:syz-executor0][<ffffff90080883f0>] elO_svc_naked +0x24/0x28 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]The buggy address belongs to the variable: [26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]Memory state around the buggy address: [26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00 [26364:syz-executor0][name:report&] ^ [26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa [26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa [26364:syz-executor0][name:report&] [26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint [26364:syz-executor0]------------[cut here]------------ After checking the source code, we've found there might be an out-of-bounds access to "config[len - 1]" array when the variable "len" is zero. Signed-off-by: Macpaul Lin <macpaul@gmail.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06Revert "tty: xilinx_uartps: Correct return value in probe"Greg Kroah-Hartman
This reverts commit eca42d4cf3c591c36312c52707e0a712e0c7256a. During review it was rejected, so drop it from the tree. Cc: Rajan Vaja <RAJANV@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty/ldsem: Decrement wait_readers on timeouted down_read()Dmitry Safonov
It seems like when ldsem_down_read() fails with timeout, it misses update for sem->wait_readers. By that reason, when writer finally releases write end of the semaphore __ldsem_wake_readers() does adjust sem->count with wrong value: sem->wait_readers * (LDSEM_ACTIVE_BIAS - LDSEM_WAIT_BIAS) I.e, if update comes with 1 missed wait_readers decrement, sem->count will be 0x100000001 which means that there is active reader and it'll make any further writer to fail in acquiring the semaphore. It looks like, this is a dead-code, because ldsem_down_read() is never called with timeout different than MAX_SCHEDULE_TIMEOUT, so it might be worth to delete timeout parameter and error path fall-back.. Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty/ldsem: Add lockdep asserts for ldisc_semDmitry Safonov
Make sure under CONFIG_LOCKDEP that each change to line discipline is done with held write semaphor. Otherwise potential reader will have a good time dereferencing incomplete/uninitialized ldisc. An exception here is tty_ldisc_open(), as it's called without ldisc_sem locked by tty_init_dev() => tty_ldisc_setup() for the tty->link. It seem valid as tty_init_dev() will call tty_driver_install_tty() which will find ops->install(). Install will establish tty->link in pty_common_install(), just after allocation of slave tty with alloc_tty_struct(). So, no one should have a reference to slave pty yet. Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty/ldsem: Convert to regular lockdep annotationsPeter Zijlstra
For some reason ldsem has its own lockdep wrappers, make them go away. Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: Simplify tty->count math in tty_reopen()Dmitry Safonov
As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter. Simplify math by increasing the counter after reinit success. Cc: Jiri Slaby <jslaby@suse.com> Link: lkml.kernel.org/r/<20180829022353.23568-2-dima@arista.com> Suggested-by: Jiri Slaby <jslaby@suse.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: Don't block on IO when ldisc change is pendingDmitry Safonov
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>
2018-12-05tty: Hold tty_ldisc_lock() during tty_reopen()Dmitry Safonov
tty_ldisc_reinit() doesn't race with neither tty_ldisc_hangup() nor set_ldisc() nor tty_ldisc_release() as they use tty lock. But it races with anyone who expects line discipline to be the same after hoding read semaphore in tty_ldisc_ref(). We've seen the following crash on v4.9.108 stable: BUG: unable to handle kernel paging request at 0000000000002260 IP: [..] n_tty_receive_buf_common+0x5f/0x86d Workqueue: events_unbound flush_to_ldisc Call Trace: [..] n_tty_receive_buf2 [..] tty_ldisc_receive_buf [..] flush_to_ldisc [..] process_one_work [..] worker_thread [..] kthread [..] ret_from_fork tty_ldisc_reinit() should be called with ldisc_sem hold for writing, which will protect any reader against line discipline changes. Cc: Jiri Slaby <jslaby@suse.com> Cc: stable@vger.kernel.org # b027e2298bd5 ("tty: fix data race between tty_init_dev and flush of buf") Reviewed-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+3aa9784721dfb90e984d@syzkaller.appspotmail.com Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Dmitry Safonov <dima@arista.com> Tested-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty/ldsem: Wake up readers after timed out down_write()Dmitry Safonov
ldsem_down_read() will sleep if there is pending writer in the queue. If the writer times out, readers in the queue should be woken up, otherwise they may miss a chance to acquire the semaphore until the last active reader will do ldsem_up_read(). There was a couple of reports where there was one active reader and other readers soft locked up: Showing all locks held in the system: 2 locks held by khungtaskd/17: #0: (rcu_read_lock){......}, at: watchdog+0x124/0x6d1 #1: (tasklist_lock){.+.+..}, at: debug_show_all_locks+0x72/0x2d3 2 locks held by askfirst/123: #0: (&tty->ldisc_sem){.+.+.+}, at: ldsem_down_read+0x46/0x58 #1: (&ldata->atomic_read_lock){+.+...}, at: n_tty_read+0x115/0xbe4 Prevent readers wait for active readers to release ldisc semaphore. Link: lkml.kernel.org/r/20171121132855.ajdv4k6swzhvktl6@wfg-t540p.sh.intel.com Link: lkml.kernel.org/r/20180907045041.GF1110@shao2-debian Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty/sysrq: Do not call sync directly from sysrq_do_reset()Mark Tomlinson
sysrq_do_reset() is called in softirq context, so it cannot call sync() directly. Instead, call orderly_reboot(), which creates a work item to run /sbin/reboot, or do emergency_sync and restart if the command fails. Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: serial: 8250_mtk: always resume the device in probe.Peter Shih
serial8250_register_8250_port calls uart_config_port, which calls config_port on the port before it tries to power on the port. So we need the port to be on before calling serial8250_register_8250_port. Change the code to always do a runtime resume in probe before registering port, and always do a runtime suspend in remove. This basically reverts the change in commit 68e5fc4a255a ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling"), but still use pm_runtime callbacks. Fixes: 68e5fc4a255a ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling") Signed-off-by: Peter Shih <pihsun@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05USB: serial: console: fix reported terminal settingsJohan Hovold
The USB-serial console implementation has never reported the actual terminal settings used. Despite storing the corresponding cflags in its struct console, these were never honoured on later tty open() where the tty termios would be left initialised to the driver defaults. Unlike the serial console implementation, the USB-serial code calls subdriver open() already at console setup. While calling set_termios() and write() before open() looks like it could work for some USB-serial drivers, others definitely do not expect this, so modelling this after serial core is going to be intrusive, if at all possible. Instead, use a (renamed) tty helper to save the termios data used at console setup so that the tty termios reflects the actual terminal settings after a subsequent tty open(). Note that the calls to tty_init_termios() (tty_driver_install()) and tty_save_termios() are serialised using the disconnect mutex. This specifically fixes a regression that was triggered by a recent change adding software flow control to the pl2303 driver: a getty trying to disable flow control while leaving the baud rate unchanged would now also set the baud rate to the driver default (prior to the flow-control change this had been a noop). Fixes: 7041d9c3f01b ("USB: serial: pl2303: add support for tx xon/xoff flow control") Cc: stable <stable@vger.kernel.org> # 4.18 Cc: Florian Zumbiehl <florz@florz.de> Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org>
2018-12-05serial: 8250-mtk: add uart DMA supportLong Cheng
Modify uart register to support DMA function. Signed-off-by: Long Cheng <long.cheng@mediatek.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: xilinx_uartps: Correct return value in probeRajan Vaja
Existing driver checks for alternate clock if devm_clk_get() fails and returns error code for last clock failure. If xilinx_uartps is called before clock driver, devm_clk_get() returns -EPROBE_DEFER. In this case, probe should not check for alternate clock as main clock is already present in DTS and return -EPROBE_DEFER only. This patch fixes it by not checking for alternate clock when main clock get returns -EPROBE_DEFER. Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05tty: serial: qcom_geni_serial: Fix softlockRyan Case
Transfers were being divided into device FIFO sized (64 byte max) operations which would poll for completion within a spin_lock_irqsave / spin_unlock_irqrestore block. This both made things slow by waiting for the FIFO to completely drain before adding further data and would also result in softlocks on large transmissions. This patch allows larger transfers with continuous FIFO additions as space becomes available and removes polling from the interrupt handler. Signed-off-by: Ryan Case <ryandcase@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05Revert "serial/sunsu: add missing of_node_put()"Greg Kroah-Hartman
This reverts commit 20d8e8611eb0596047fd4389be7a7203a883b9bf. As David Miller points out, it's wrong. Reported-by: David Miller <davem@davemloft.net> Cc: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-02drivers/tty: add missing of_node_put()Yangtao Li
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. This place is not doing this, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27serdev: document the write functions using kernel-docJohan Hovold
Document the asynchronous serdev_device_write_buf() and synchronous serdev_device_write() functions using kernel-doc. Specifically, mention that writing data only means that data has been buffered by the controller, and that the synchronous helper depends on serdev_device_write_wakeup() being called in the driver write_wakeup() callback. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serdev: make synchronous write helper interruptibleJohan Hovold
Allow the synchronous serdev_device_write() helper to be interrupted. This is useful for cases where I/O is performed on behalf of user space and we don't want to block indefinitely when using flow control. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serdev: make synchronous write return bytes writtenJohan Hovold
Make the synchronous serdev_device_write() helper behave analogous to the asynchronous serdev_device_write_buf() by returning the number of bytes written (or rather buffered) also on timeout. This will allow drivers to distinguish the case where data was partially written from the case where no data was written. Also update the only two users that checked the return value. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serdev: use zero to indicate infinite write timeoutJohan Hovold
Use zero to indicate infinite timeout for the synchronous serdev_device_write() helper. This allows drivers to specify an infinite timeout without knowing about serdev implementation details, while also allowing the same timeout argument to be used for both serdev_device_write() and serdev_device_wait_until_sent(). Note that passing zero to the current helper makes no sense; just call the asynchronous serdev_device_write_buf() directly instead. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27sysrq: Use panic() to force a crashMatthias Kaehlcke
sysrq_handle_crash() currently forces a crash by dereferencing a NULL pointer, which is undefined behavior in C. Just call panic() instead, which is simpler and doesn't depend on compiler specific handling of the undefined behavior. Remove the comment on why the RCU lock needs to be released, it isn't accurate anymore since the crash now isn't handled by the page fault handler (for reference: the comment was added by commit 984cf355aeaa ("sysrq: Fix warning in sysrq generated crash.")). Releasing the lock is still good practice though. Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27tty/sysrq: add of_node_put()Yangtao Li
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. bl_idle_init() doesn't do that, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27tty: do not set TTY_IO_ERROR flag if console portChanho Park
Since Commit 761ed4a94582 ('tty: serial_core: convert uart_close to use tty_port_close') and Commit 4dda864d7307 ('tty: serial_core: Fix serial console crash on port shutdown), a serial port which is used as console can be stuck when logging out if there is a remained process. After logged out, agetty will try to grab the serial port but it will be failed because the previous process did not release the port correctly. To fix this, TTY_IO_ERROR bit should not be enabled of tty_port_close if the port is console port. Reproduce step: - Run background processes from serial console $ while true; do sleep 10; done & - Log out $ logout -> Stuck - Read journal log by journalctl | tail Jan 28 16:07:01 ubuntu systemd[1]: Stopped Serial Getty on ttyAMA0. Jan 28 16:07:01 ubuntu systemd[1]: Started Serial Getty on ttyAMA0. Jan 28 16:07:02 ubuntu agetty[1643]: /dev/ttyAMA0: not a tty Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Rob Herring <robh@kernel.org> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Chanho Park <parkch98@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial: imx: fix error handling in console_setupStefan Agner
The ipg clock only needs to be unprepared in case preparing per clock fails. The ipg clock has already disabled at the point. Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check") Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial: mvebu-uart: initialize over sampling stack registerMiquel Raynal
The baudrate derivation relies on the state of the programmable over sampling stack (OSAMP register) being empty, while never initializing it. Set all the fields of this register to 0 (except reserved areas) to ensure a x16 divisor, as assumed by the driver. The suspend/resume callbacks are untouched because they already save/restore correctly this register. Suggested-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial: mvebu-uart: clarify the baud rate derivationMiquel Raynal
The current comment in ->set_baud_rate() is rather incomplete as it fails to describe what are the actual stages for the baudrate derivation. Replace this comment with something more explicit and close to the functional specification. Also adapt the variable names to it. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial/sunsu: add missing of_node_put()Yangtao Li
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. This place is not doing this, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27drivers/tty: add missing of_node_put()Yangtao Li
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. This place is not doing this, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27serial-uartlite: fix null pointer dereference on pointer portColin Ian King
Pointer port is dereferenced on port->private_data when assigning pointer pdata before port is null checked, leading to a potential null pointer dereference. Fix this by assigning pdata after the null pointer check on port. Detected by CoverityScan, CID#1475434 ("Dereference before null check") Fixes: 3b209d253e7f ("serial-uartlite: Do not use static struct uart_driver out of probe()") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-26audit: use current whenever possiblePaul Moore
There are many places, notably audit_log_task_info() and audit_log_exit(), that take task_struct pointers but in reality they are always working on the current task. This patch eliminates the task_struct arguments and uses current directly which allows a number of cleanups as well. Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-11Merge 4.20-rc2 into tty-nextGreg Kroah-Hartman
We want the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-10Merge tag 'tty-4.20-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are some small tty fixes for 4.20-rc2 One of these missed the original 4.19-final release, I missed that I hadn't done a pull request for it as it was in linux-next and my branch for a long time, that's my fault. The others are small, fixing some reported issues and finally fixing the termios mess for alpha so that glibc has a chance to implement some missing functionality that has been pending for many years now. All of these have been in linux-next with no reported issues" * tag 'tty-4.20-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: sh-sci: Fix could not remove dev_attr_rx_fifo_timeout arch/alpha, termios: implement BOTHER, IBSHIFT and termios2 termios, tty/tty_baudrate.c: fix buffer overrun vt: fix broken display when running aptitude serial: sh-sci: Fix receive on SCIFA/SCIFB variants with DMA
2018-11-09serial: sh-sci: Fix could not remove dev_attr_rx_fifo_timeoutYoshihiro Shimoda
This patch fixes an issue that the sci_remove() could not remove dev_attr_rx_fifo_timeout because uart_remove_one_port() set the port->port.type to PORT_UNKNOWN. Reported-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> Fixes: 5d23188a473d ("serial: sh-sci: make RX FIFO parameters tunable via sysfs") Cc: <stable@vger.kernel.org> # v4.11+ Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09serial: 8250: Process sysrq at port unlock timeDouglas Anderson
Let's take advantage of the new ("serial: core: Allow processing sysrq at port unlock time") to handle sysrqs more cleanly. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09serial: qcom_geni_serial: Process sysrq at port unlock timeDouglas Anderson
Let's take advantage of the new ("serial: core: Allow processing sysrq at port unlock time") to handle sysrqs more cleanly. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09serial: qcom_geni_serial: Finish supporting sysrqDouglas Anderson
The geni serial driver already had some sysrq code in it, but since SUPPORT_SYSRQ wasn't defined the code didn't do anything useful. Let's make it useful by adding that define using the same formula found in other serial drivers. In order to prevent deadlock, we'll take a page from the 'msm_serial.c' where the spinlock is released around uart_handle_sysrq_char(). This seemed better than copying from '8250_port.c' where we skip locking in the console_write function since the '8250_port.c' method can cause lockdep warnings when dropping into kgdb. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250Florian Fainelli
It is way too easy to miss enabling SERIAL_OF_PLATFORM which would result in the inability for the kernel to have a valid console device, which can be seen with: Warning: unable to open an initial console. and then: Run /init as init process Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000100 Since SERIAL_OF_PLATFORM already depends on SERIAL_8250 && OF there really is no drawback to defaulting this config to the value of SERIAL_8250. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09serial: set suppress_bind_attrs flag only if builtinAnders Roxell
When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init). devtmpfs gets killed because we try to remove a file and decrement the wb reference count before the noop_backing_device_info gets initialized. [ 0.332075] Serial: AMBA PL011 UART driver [ 0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1 [ 0.502382] console [ttyAMA0] enabled [ 0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000 [ 0.516053] Mem abort info: [ 0.516222] ESR = 0x96000004 [ 0.516417] Exception class = DABT (current EL), IL = 32 bits [ 0.516641] SET = 0, FnV = 0 [ 0.516826] EA = 0, S1PTW = 0 [ 0.516984] Data abort info: [ 0.517149] ISV = 0, ISS = 0x00000004 [ 0.517339] CM = 0, WnR = 0 [ 0.517553] [0000800074c12000] user address but active_mm is swapper [ 0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 0.518305] Modules linked in: [ 0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82 [ 0.519307] Hardware name: linux,dummy-virt (DT) [ 0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.519959] pc : __destroy_inode+0x94/0x2a8 [ 0.520212] lr : __destroy_inode+0x78/0x2a8 [ 0.520401] sp : ffff0000098c3b20 [ 0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714 [ 0.520904] x27: 0000000000002000 x26: 0000000000002000 [ 0.521179] x25: ffff000009583000 x24: 0000000000000000 [ 0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0 [ 0.521737] x21: ffff0000093f9338 x20: 0000000000000000 [ 0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400 [ 0.522376] x17: 0000000000000000 x16: 0000000000000000 [ 0.522727] x15: 0000000000000400 x14: 0000000000000400 [ 0.523068] x13: 0000000000000001 x12: 0000000000000001 [ 0.523421] x11: 0000000000000000 x10: 0000000000000970 [ 0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190 [ 0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88 [ 0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb [ 0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff [ 0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000 [ 0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____)) [ 0.525529] Call trace: [ 0.525806] __destroy_inode+0x94/0x2a8 [ 0.526108] destroy_inode+0x34/0x88 [ 0.526370] evict+0x144/0x1c8 [ 0.526636] iput+0x184/0x230 [ 0.526871] dentry_unlink_inode+0x118/0x130 [ 0.527152] d_delete+0xd8/0xe0 [ 0.527420] vfs_unlink+0x240/0x270 [ 0.527665] handle_remove+0x1d8/0x330 [ 0.527875] devtmpfsd+0x138/0x1c8 [ 0.528085] kthread+0x14c/0x158 [ 0.528291] ret_from_fork+0x10/0x18 [ 0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04) [ 0.529367] ---[ end trace 5a3dee47727f877c ]--- Rework to set suppress_bind_attrs flag to avoid removing the device when CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and xilinx_uartps as well. Co-developed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>