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2015-05-16xen/console: Update console event channel on resumeBoris Ostrovsky
commit b9d934f27c91b878c4b2e64299d6e419a4022f8d upstream. After a resume the hypervisor/tools may change console event channel number. We should re-query it. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-05-15tty/serial: at91: maxburst was missing for dma transfersLudovic Desroches
commit a8d4e01637902311c5643b69a5c80e2805f04054 upstream. Maxburst was not set when doing the dma slave configuration. This value is checked by the recently introduced xdmac. It causes an error when doing the slave configuration and so prevents from using dma. Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-05-15serial: of-serial: Remove device_type = "serial" registrationMichal Simek
commit 6befa9d883385c580369a2cc9e53fbf329771f6d upstream. Do not probe all serial drivers by of_serial.c which are using device_type = "serial"; property. Only drivers which have valid compatible strings listed in the driver should be probed. When PORT_UNKNOWN is setup probe will fail anyway. Arnd quotation about driver historical background: "when I wrote that driver initially, the idea was that it would get used as a stub to hook up all other serial drivers but after that, the common code learned to create platform devices from DT" This patch fix the problem with on the system with xilinx_uartps and 16550a where of_serial failed to register for xilinx_uartps and because of irq_dispose_mapping() removed irq_desc. Then when xilinx_uartps was asking for irq with request_irq() EINVAL is returned. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-04-22n_tty: Fix read buffer overwrite when no newlinePeter Hurley
commit fb5ef9e7da39968fec6d6f37f20a23d23740c75e upstream. In canon mode, the read buffer head will advance over the buffer tail if the input > 4095 bytes without receiving a line termination char. Discard additional input until a line termination is received. Before evaluating for overflow, the 'room' value is normalized for I_PARMRK and 1 byte is reserved for line termination (even in !icanon mode, in case the mode is switched). The following table shows the transform: actual buffer | 'room' value before overflow calc space avail | !I_PARMRK | I_PARMRK -------------------------------------------------- 0 | -1 | -1 1 | 0 | 0 2 | 1 | 0 3 | 2 | 0 4+ | 3 | 1 When !icanon or when icanon and the read buffer contains newlines, normalized 'room' values of -1 and 0 are clamped to 0, and 'overflow' is 0, so read_head is not adjusted and the input i/o loop exits (setting no_room if called from flush_to_ldisc()). No input is discarded since the reader does have input available to read which ensures forward progress. When icanon and the read buffer does not contain newlines and the normalized 'room' value is 0, then overflow and room are reset to 1, so that the i/o loop will process the next input char normally (except for parity errors which are ignored). Thus, erasures, signalling chars, 7-bit mode, etc. will continue to be handled properly. If the input char processed was not a line termination char, then the canon_head index will not have advanced, so the normalized 'room' value will now be -1 and 'overflow' will be set, which indicates the read_head can safely be reset, effectively erasing the last char processed. If the input char processed was a line termination, then the canon_head index will have advanced, so 'overflow' is cleared to 0, the read_head is not reset, and 'room' is cleared to 0, which exits the i/o loop (because the reader now have input available to read which ensures forward progress). Note that it is possible for a line termination to be received, and for the reader to copy the line to the user buffer before the input i/o loop is ready to process the next input char. This is why the i/o loop recomputes the room/overflow state with every input char while handling overflow. Finally, if the input data was processed without receiving a line termination (so that overflow is still set), the pty driver must receive a write wakeup. A pty writer may be waiting to write more data in n_tty_write() but without unthrottling here that wakeup will not arrive, and forward progress will halt. (Normally, the pty writer is woken when the reader reads data out of the buffer and more space become available). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> (backported from commit fb5ef9e7da39968fec6d6f37f20a23d23740c75e) Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
2015-04-22tty: serial: fsl_lpuart: clear receive flag on FIFO flushStefan Agner
commit 8e4934c6d6c659e22b1b746af4196683e77ce6ca upstream. When the receiver was enabled during startup, a character could have been in the FIFO when the UART get initially used. The driver configures the (receive) watermark level, and flushes the FIFO. However, the receive flag (RDRF) could still be set at that stage (as mentioned in the register description of UARTx_RWFIFO). This leads to an interrupt which won't be handled properly in interrupt mode: The receive interrupt function lpuart_rxint checks the FIFO count, which is 0 at that point (due to the flush during initialization). The problem does not manifest when using DMA to receive characters. Fix this situation by explicitly read the status register, which leads to clearing of the RDRF flag. Due to the flush just after the status flag read, a explicit data read is not to required. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-04-21n_tty: Merge .receive_buf() flavorsPeter Hurley
commit 5c32d12378313e0096ea0d450462aa638a90fb6e upstream. N_TTY's direct and flow-controlled flavors of the .receive_buf() method are nearly identical; fold together. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-04-09Change email address for 8250_pciRussell King
commit f2e0ea861117bda073d1d7ffbd3120c07c0d5d34 upstream. I'm still receiving reports to my email address, so let's point this at the linux-serial mailing list instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-03-12tty: fix up atime/mtime mess, take fourJiri Slaby
commit f0bf0bd07943bfde8f5ac39a32664810a379c7d3 upstream. This problem was taken care of three times already in * b0de59b5733d18b0d1974a060860a8b5c1b36a2e (TTY: do not update atime/mtime on read/write), * 37b7f3c76595e23257f61bd80b223de8658617ee (TTY: fix atime/mtime regression), and * b0b885657b6c8ef63a46bc9299b2a7715d19acde (tty: fix up atime/mtime mess, take three) But it still misses one point. As John Paul correctly points out, we do not care about setting date. If somebody ever changes wall time backwards (by mistake for example), tty timestamps are never updated until the original wall time passes. So check the absolute difference of times and if it large than "8 seconds or so", always update the time. That means we will update immediatelly when changing time. Ergo, CAP_SYS_TIME can foul the check, but it was always that way. Thanks John for serving me this so nicely debugged. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: John Paul Perry <john_paul.perry@alcatel-lucent.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-03-12TTY: fix tty_wait_until_sent on 64-bit machinesJohan Hovold
commit 79fbf4a550ed6a22e1ae1516113e6c7fa5d56a53 upstream. Fix overflow bug in tty_wait_until_sent on 64-bit machines, where an infinite timeout (0) would be passed to the underlying tty-driver's wait_until_sent-operation as a negative timeout (-1), causing it to return immediately. This manifests itself for example as tcdrain() returning immediately, drivers not honouring the drain flags when setting terminal attributes, or even dropped data on close as a requested infinite closing-wait timeout would be ignored. The first symptom was reported by Asier LLANO who noted that tcdrain() returned prematurely when using the ftdi_sio usb-serial driver. Fix this by passing 0 rather than MAX_SCHEDULE_TIMEOUT (LONG_MAX) to the underlying tty driver. Note that the serial-core wait_until_sent-implementation is not affected by this bug due to a lucky chance (comparison to an unsigned maximum timeout), and neither is the cyclades one that had an explicit check for negative timeouts, but all other tty drivers appear to be affected. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: ZIV-Asier Llano Palacios <asier.llano@cgglobal.com> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-03-01vt: provide notifications on selection changesNicolas Pitre
commit 19e3ae6b4f07a87822c1c9e7ed99d31860e701af upstream. The vcs device's poll/fasync support relies on the vt notifier to signal changes to the screen content. Notifier invocations were missing for changes that comes through the selection interface though. Fix that. Tested with BRLTTY 5.2. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: Dave Mielke <dave@mielke.cc> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-03-01tty/serial: at91: fix error handling in atmel_serial_probe()Cyrille Pitchen
commit 6fbb9bdf0f3fbe23aeff806489791aa876adaffb upstream. -EDEFER error wasn't handle properly by atmel_serial_probe(). As an example, when atmel_serial_probe() is called for the first time, we pass the test_and_set_bit() test to check whether the port has already been initalized. Then we call atmel_init_port(), which may return -EDEFER, possibly returned before by clk_get(). Consequently atmel_serial_probe() used to return this error code WITHOUT clearing the port bit in the "atmel_ports_in_use" mask. When atmel_serial_probe() was called for the second time, it used to fail on the test_and_set_bit() function then returning -EBUSY. When atmel_serial_probe() fails, this patch make it clear the port bit in the "atmel_ports_in_use" mask, if needed, before returning the error code. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-03-01tty: Prevent untrappable signals from malicious programPeter Hurley
commit 37480a05685ed5b8e1b9bf5e5c53b5810258b149 upstream. Commit 26df6d13406d1a5 ("tty: Add EXTPROC support for LINEMODE") allows a process which has opened a pty master to send _any_ signal to the process group of the pty slave. Although potentially exploitable by a malicious program running a setuid program on a pty slave, it's unknown if this exploit currently exists. Limit to signals actually used. Cc: Theodore Ts'o <tytso@mit.edu> Cc: Howard Chu <hyc@symas.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-01-26n_tty: Fix read_buf race condition, increment read_head after pushing dataChristian Riesch
commit 8bfbe2de769afda051c56aba5450391670e769fc upstream. Commit 19e2ad6a09f0c06dbca19c98e5f4584269d913dd ("n_tty: Remove overflow tests from receive_buf() path") moved the increment of read_head into the arguments list of read_buf_addr(). Function calls represent a sequence point in C. Therefore read_head is incremented before the character c is placed in the buffer. Since the circular read buffer is a lock-less design since commit 6d76bd2618535c581f1673047b8341fd291abc67 ("n_tty: Make N_TTY ldisc receive path lockless"), this creates a race condition that leads to communication errors. This patch modifies the code to increment read_head _after_ the data is placed in the buffer and thus fixes the race for non-SMP machines. To fix the problem for SMP machines, memory barriers must be added in a separate patch. Signed-off-by: Christian Riesch <christian.riesch@omicron.at> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-01-26serial: samsung: wait for transfer completion before clock disableRobert Baldyga
commit 1ff383a4c3eda8893ec61b02831826e1b1f46b41 upstream. This patch adds waiting until transmit buffer and shifter will be empty before clock disabling. Without this fix it's possible to have clock disabled while data was not transmited yet, which causes unproper state of TX line and problems in following data transfers. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-01-07tty: Fix pty master poll() after slave closes v2Francesco Ruggeri
commit c4dc304677e8d566572c4738d95c48be150c6606 upstream. Commit f95499c3030f ("n_tty: Don't wait for buffer work in read() loop") introduces a race window where a pty master can be signalled that the pty slave was closed before all the data that the slave wrote is delivered. Commit f8747d4a466a ("tty: Fix pty master read() after slave closes") fixed the problem in case of n_tty_read, but the problem still exists for n_tty_poll. This can be seen by running 'for ((i=0; i<100;i++));do ./test.py ;done' where test.py is: import os, select, pty (pid, pty_fd) = pty.fork() if pid == 0: os.write(1, 'This string should be received by parent') else: poller = select.epoll() poller.register( pty_fd, select.EPOLLIN ) ready = poller.poll( 1 * 1000 ) for fd, events in ready: if not events & select.EPOLLIN: print 'missed POLLIN event' else: print os.read(fd, 100) poller.close() The string from the slave is missed several times. This patch takes the same approach as the fix for read and special cases this condition for poll. Tested on 3.16. Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-11-19parport: Add support for the WCH353 1S/1P multi-IO cardEzequiel Garcia
commit feb5814254094c306429fe6d7b9c534fa0250f4c upstream. This Multi-IO card has one serial 16550-like and one parallel port connector. Here's the lspci output, after this commit is applied: 03:07.0 Serial controller: Device 4348:5053 (rev 10) (prog-if 02 [16550]) Subsystem: Device 4348:5053 Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Interrupt: pin A routed to IRQ 21 Region 0: I/O ports at cf00 [size=8] Region 1: I/O ports at ce00 [size=8] Kernel driver in use: parport_serial Kernel modules: 8250_pci, parport_serial This commit adds an entry with the device ID to the blacklist declared in 8250_pci to prevent the driver from taking ownership. Also, and as was done for the 2S/1P variant, add a quirk to skip autodetection and set the correct type to 16550A clone. Proper entries are added to parport_serial, to support the device parallel and serial ports. Cc: Gianluca Anzolin <gianluca@sottospazio.it> Cc: Alan Cox <alan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-11-13tty: Fix high cpu load if tty is unreleaseablePeter Hurley
commit 37b164578826406a173ca7c20d9ba7430134d23e upstream. Kernel oops can cause the tty to be unreleaseable (for example, if n_tty_read() crashes while on the read_wait queue). This will cause tty_release() to endlessly loop without sleeping. Use a killable sleep timeout which grows by 2n+1 jiffies over the interval [0, 120 secs.) and then jumps to forever (but still killable). NB: killable just allows for the task to be rewoken manually, not to be terminated. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-11-13serial: Fix divide-by-zero fault in uart_get_divisor()Peter Hurley
commit 547039ec502076e60034eeb79611df3433a99b7d upstream. uart_get_baud_rate() will return baud == 0 if the max rate is set to the "magic" 38400 rate and the SPD_* flags are also specified. On the first iteration, if the current baud rate is higher than the max, the baud rate is clamped at the max (which in the degenerate case is 38400). On the second iteration, the now-"magic" 38400 baud rate selects the possibly higher alternate baud rate indicated by the SPD_* flag. Since only two loop iterations are performed, the loop is exited, a kernel WARNING is generated and a baud rate of 0 is returned. Reproducible with: setserial /dev/ttyS0 spd_hi base_baud 38400 Only perform the "magic" 38400 -> SPD_* baud transform on the first loop iteration, which prevents the degenerate case from recognizing the clamped baud rate as the "magic" 38400 value. Reported-by: Robert Święcki <robert@swiecki.net> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-31tty: omap-serial: fix division by zeroFrans Klaver
commit dc3187564e61260f49eceb21a4e7eb5e4428e90a upstream. If the chosen baud rate is large enough (e.g. 3.5 megabaud), the calculated n values in serial_omap_is_baud_mode16() may become 0. This causes a division by zero when calculating the difference between calculated and desired baud rates. To prevent this, cap the n13 and n16 values on 1. Division by zero in kernel. [<c00132e0>] (unwind_backtrace) from [<c00112ec>] (show_stack+0x10/0x14) [<c00112ec>] (show_stack) from [<c01ed7bc>] (Ldiv0+0x8/0x10) [<c01ed7bc>] (Ldiv0) from [<c023805c>] (serial_omap_baud_is_mode16+0x4c/0x68) [<c023805c>] (serial_omap_baud_is_mode16) from [<c02396b4>] (serial_omap_set_termios+0x90/0x8d8) [<c02396b4>] (serial_omap_set_termios) from [<c0230a0c>] (uart_change_speed+0xa4/0xa8) [<c0230a0c>] (uart_change_speed) from [<c0231798>] (uart_set_termios+0xa0/0x1fc) [<c0231798>] (uart_set_termios) from [<c022bb44>] (tty_set_termios+0x248/0x2c0) [<c022bb44>] (tty_set_termios) from [<c022c17c>] (set_termios+0x248/0x29c) [<c022c17c>] (set_termios) from [<c022c3e4>] (tty_mode_ioctl+0x1c8/0x4e8) [<c022c3e4>] (tty_mode_ioctl) from [<c0227e70>] (tty_ioctl+0xa94/0xb18) [<c0227e70>] (tty_ioctl) from [<c00cf45c>] (do_vfs_ioctl+0x4a0/0x560) [<c00cf45c>] (do_vfs_ioctl) from [<c00cf568>] (SyS_ioctl+0x4c/0x74) [<c00cf568>] (SyS_ioctl) from [<c000e480>] (ret_fast_syscall+0x0/0x30) Signed-off-by: Frans Klaver <frans.klaver@xsens.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-17serial: 8250: Add Quark X1000 to 8250_pci.cBryan O'Donoghue
commit 1ede7dcca3c4fa15a518ab0473126f9c3e621e4c upstream. Quark X1000 contains two designware derived 8250 serial ports. Each port has a unique PCI configuration space consisting of BAR0:UART BAR1:DMA respectively. Unlike the standard 8250 the register width is 32 bits for RHR,IER etc The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a bitrate of up to about 2.76 megabits per second. This patch enables standard 8250 mode Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-13serial: 8250_dma: check the result of TX buffer mappingHeikki Krogerus
commit d4089a332883ad969700aac5dd4dd5f1c4fee825 upstream. Using dma_mapping_error() to make sure the mapping did not fail. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: "Petallo, MauriceX R" <mauricex.r.petallo@intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-09-03serial: core: Preserve termios c_cflag for console resumePeter Hurley
commit ae84db9661cafc63d179e1d985a2c5b841ff0ac4 upstream. When a tty is opened for the serial console, the termios c_cflag settings are inherited from the console line settings. However, if the tty is subsequently closed, the termios settings are lost. This results in a garbled console if the console is later suspended and resumed. Preserve the termios c_cflag for the serial console when the tty is shutdown; this reflects the most recent line settings. Fixes: Bugzilla #69751, 'serial console does not wake from S3' Reported-by: Valerio Vanni <valerio.vanni@inwind.it> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-08-26sunsab: Fix detection of BREAK on sunsab serial consoleChristopher Alexander Tobias Schulze
[ Upstream commit fe418231b195c205701c0cc550a03f6c9758fd9e ] Fix detection of BREAK on sunsab serial console: BREAK detection was only performed when there were also serial characters received simultaneously. To handle all BREAKs correctly, the check for BREAK and the corresponding call to uart_handle_break() must also be done if count == 0, therefore duplicate this code fragment and pull it out of the loop over the received characters. Patch applies to 3.16-rc6. Signed-off-by: Christopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-28serial: sirf: Fix compilation failureDaniel Thompson
commit 58eb97c99da6a82c556ddec70683eb3863d4f617 upstream. After 07d410e0) serial: sirf: fix spinlock deadlock issue it is no longer possiblet to compile this driver. The rename of one of the spinlocks is faulty. After looking at the original patch I believe this is the correct fix. Compile tested using ARM's multi_v7_defconfig Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Barry Song <baohua@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-28serial: sirf: fix spinlock deadlock issueQipan Li
commit 07d410e06463f3c1c106e2bb2a7ff23eff1e71c9 upstream. commit fb78b811422cd2d8c8605949cc4cc13618347ad5 provide a workaround for kernel panic, but bring potential deadlock risk. that is in sirfsoc_rx_tmo_process_tl while enter into sirfsoc_uart_pio_rx_chars cpu hold uart_port->lock, if uart interrupt comes cpu enter into sirfsoc_uart_isr and deadlock occurs in getting uart_port->lock. the patch replace spin_lock version to spin_lock_irq* version to avoid spinlock dead lock issue. let function tty_flip_buffer_push in tasklet outof spin_lock_irq* protect area to avoid add the pair of spin_lock and spin_unlock for tty_flip_buffer_push. BTW drop self defined unused spinlock protect of tx_lock/rx_lock. 56274.220464] BUG: spinlock lockup suspected on CPU#0, swapper/0/0 [56274.223648] lock: 0xc05d9db0, .magic: dead4ead, .owner: swapper/0/0, .owner_cpu: 0 [56274.231278] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 3.10.35 #1 [56274.238241] [<c0015530>] (unwind_backtrace+0x0/0xf4) from [<c00120d8>] (show_stack+0x10/0x14) [56274.246742] [<c00120d8>] (show_stack+0x10/0x14) from [<c01b11b0>] (do_raw_spin_lock+0x110/0x184) [56274.255501] [<c01b11b0>] (do_raw_spin_lock+0x110/0x184) from [<c02124c8>] (sirfsoc_uart_isr+0x20/0x42c) [56274.264874] [<c02124c8>] (sirfsoc_uart_isr+0x20/0x42c) from [<c0075790>] (handle_irq_event_percpu+0x54/0x17c) [56274.274758] [<c0075790>] (handle_irq_event_percpu+0x54/0x17c) from [<c00758f4>] (handle_irq_event+0x3c/0x5c) [56274.284561] [<c00758f4>] (handle_irq_event+0x3c/0x5c) from [<c0077fa0>] (handle_level_irq+0x98/0xfc) [56274.293670] [<c0077fa0>] (handle_level_irq+0x98/0xfc) from [<c0074f44>] (generic_handle_irq+0x2c/0x3c) [56274.302952] [<c0074f44>] (generic_handle_irq+0x2c/0x3c) from [<c000ef80>] (handle_IRQ+0x40/0x90) [56274.311706] [<c000ef80>] (handle_IRQ+0x40/0x90) from [<c000dc80>] (__irq_svc+0x40/0x70) [56274.319697] [<c000dc80>] (__irq_svc+0x40/0x70) from [<c038113c>] (_raw_spin_unlock_irqrestore+0x10/0x48) [56274.329158] [<c038113c>] (_raw_spin_unlock_irqrestore+0x10/0x48) from [<c0200034>] (tty_port_tty_get+0x58/0x90) [56274.339213] [<c0200034>] (tty_port_tty_get+0x58/0x90) from [<c0212008>] (sirfsoc_uart_pio_rx_chars+0x1c/0xc8) [56274.349097] [<c0212008>] (sirfsoc_uart_pio_rx_chars+0x1c/0xc8) from [<c0212ef8>] (sirfsoc_rx_tmo_process_tl+0xe4/0x1fc) [56274.359853] [<c0212ef8>] (sirfsoc_rx_tmo_process_tl+0xe4/0x1fc) from [<c0027c04>] (tasklet_action+0x84/0x114) [56274.369739] [<c0027c04>] (tasklet_action+0x84/0x114) from [<c0027db4>] (__do_softirq+0x120/0x200) [56274.378585] [<c0027db4>] (__do_softirq+0x120/0x200) from [<c0027f44>] (do_softirq+0x54/0x5c) [56274.386998] [<c0027f44>] (do_softirq+0x54/0x5c) from [<c00281ec>] (irq_exit+0x9c/0xd0) [56274.394899] [<c00281ec>] (irq_exit+0x9c/0xd0) from [<c000ef84>] (handle_IRQ+0x44/0x90) [56274.402790] [<c000ef84>] (handle_IRQ+0x44/0x90) from [<c000dc80>] (__irq_svc+0x40/0x70) [56274.410774] [<c000dc80>] (__irq_svc+0x40/0x70) from [<c0288af4>] (cpuidle_enter_state+0x50/0xe0) [56274.419532] [<c0288af4>] (cpuidle_enter_state+0x50/0xe0) from [<c0288c34>] (cpuidle_idle_call+0xb0/0x148) [56274.429080] [<c0288c34>] (cpuidle_idle_call+0xb0/0x148) from [<c000f3ac>] (arch_cpu_idle+0x8/0x38) [56274.438016] [<c000f3ac>] (arch_cpu_idle+0x8/0x38) from [<c0059344>] (cpu_startup_entry+0xfc/0x140) [56274.446956] [<c0059344>] (cpu_startup_entry+0xfc/0x140) from [<c04a3a54>] (start_kernel+0x2d8/0x2e4) Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-18tty: Correct INPCK handlingPeter Hurley
commit 66528f90669691c85c73bea4f0c9f4a5857c4cab upstream. If INPCK is not set, input parity detection should be disabled. This means parity errors should not be received from the tty driver, and the data received should be treated normally. SUS v3, 11.2.2, General Terminal Interface - Input Modes, states: "If INPCK is set, input parity checking shall be enabled. If INPCK is not set, input parity checking shall be disabled, allowing output parity generation without input parity errors. Note that whether input parity checking is enabled or disabled is independent of whether parity detection is enabled or disabled (see Control Modes). If parity detection is enabled but input parity checking is disabled, the hardware to which the terminal is connected shall recognize the parity bit, but the terminal special file shall not check whether or not this bit is correctly set." Ignore parity errors reported by the tty driver when INPCK is not set, and handle the received data normally. Fixes: Bugzilla #71681, 'Improvement of n_tty_receive_parity_error from n_tty.c' Reported-by: Ivan <athlon_@mail.ru> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-18serial: Fix IGNBRK handlingPeter Hurley
commit ef8b9ddcb45fa3b1e11acd72be2398001e807d14 upstream. If IGNBRK is set without either BRKINT or PARMRK set, some uart drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the line discipline, when it should send either nothing or the TTYBREAK flag set. This happens because the read_status_mask masks out the BI condition, which uart_insert_char() then interprets as a normal 0x00 byte. SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General Terminal Interface - Input Modes, states: "If IGNBRK is set, a break condition detected on input shall be ignored; that is, not put on the input queue and therefore not read by any process." Fix read_status_mask to include the BI bit if IGNBRK is set; the lsr status retains the BI bit if a BREAK is recv'd, which is subsequently ignored in uart_insert_char() when masked with the ignore_status_mask. Affected drivers: 8250 - all serial_txx9 mfd amba-pl010 amba-pl011 atmel_serial bfin_uart dz ip22zilog max310x mxs-auart netx-serial pnx8xxx_uart pxa sb1250-duart sccnxp serial_ks8695 sirfsoc_uart st-asc vr41xx_siu zs sunzilog fsl_lpuart sunsab ucc_uart bcm63xx_uart sunsu efm32-uart pmac_zilog mpsc msm_serial m32r_sio Unaffected drivers: omap-serial rp2 sa1100 imx icom Annotated for fixes: altera_uart mcf Drivers without break detection: 21285 xilinx-uartps altera_jtaguart apbuart arc-uart clps711x max3100 uartlite msm_serial_hs nwpserial lantiq vt8500_serial Unknown: samsung mpc52xx_uart bfin_sport_uart cpm_uart/core Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag' Reported-by: Ivan <athlon_@mail.ru> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-02serial: 8250_dw: Fix LCR workaround regressionJames Hogan
commit 6979f8d28049879e6147767d93ba6732c8bd94f4 upstream. Commit c49436b657d0 (serial: 8250_dw: Improve unwritable LCR workaround) caused a regression. It added a check that the LCR was written properly to detect and workaround the busy quirk, but the behaviour of bit 5 (UART_LCR_SPAR) differs between IP versions 3.00a and 3.14c per the docs. On older versions this caused the check to fail and it would repeatedly force idle and rewrite the LCR register, causing delays and preventing any input from serial being received. This is fixed by masking out UART_LCR_SPAR before making the comparison. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Tim Kryger <tim.kryger@linaro.org> Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Cc: Matt Porter <matt.porter@linaro.org> Cc: Markus Mayer <markus.mayer@linaro.org> Tested-by: Tim Kryger <tim.kryger@linaro.org> Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-02serial: 8250_dw: Improve unwritable LCR workaroundTim Kryger
commit c49436b657d0a56a6ad90d14a7c3041add7cf64d upstream. When configured with UART_16550_COMPATIBLE=NO or in versions prior to the introduction of this option, the Designware UART will ignore writes to the LCR if the UART is busy. The current workaround saves a copy of the last written LCR and re-writes it in the ISR for a special interrupt that is raised when a write was ignored. Unfortunately, interrupts are typically disabled prior to performing a sequence of register writes that include the LCR so the point at which the retry occurs is too late. An example is serial8250_do_set_termios() where an ignored LCR write results in the baud divisor not being set and instead a garbage character is sent out the transmitter. Furthermore, since serial_port_out() offers no way to indicate failure, a serious effort must be made to ensure that the LCR is actually updated before returning back to the caller. This is difficult, however, as a UART that was busy during the first attempt is likely to still be busy when a subsequent attempt is made unless some extra action is taken. This updated workaround reads back the LCR after each write to confirm that the new value was accepted by the hardware. Should the hardware ignore a write, the TX/RX FIFOs are cleared and the receive buffer read before attempting to rewrite the LCR out of the hope that doing so will force the UART into an idle state. While this may seem unnecessarily aggressive, writes to the LCR are used to change the baud rate, parity, stop bit, or data length so the data that may be lost is likely not important. Admittedly, this is far from ideal but it seems to be the best that can be done given the hardware limitations. Lastly, the revised workaround doesn't touch the LCR in the ISR, so it avoids the possibility of a "serial8250: too much work for irq" lock up. This problem is rare in real situations but can be reproduced easily by wiring up two UARTs and running the following commands. # stty -F /dev/ttyS1 echo # stty -F /dev/ttyS2 echo # cat /dev/ttyS1 & [1] 375 # echo asdf > /dev/ttyS1 asdf [ 27.700000] serial8250: too much work for irq96 [ 27.700000] serial8250: too much work for irq96 [ 27.710000] serial8250: too much work for irq96 [ 27.710000] serial8250: too much work for irq96 [ 27.720000] serial8250: too much work for irq96 [ 27.720000] serial8250: too much work for irq96 [ 27.730000] serial8250: too much work for irq96 [ 27.730000] serial8250: too much work for irq96 [ 27.740000] serial8250: too much work for irq96 Signed-off-by: Tim Kryger <tim.kryger@linaro.org> Reviewed-by: Matt Porter <matt.porter@linaro.org> Reviewed-by: Markus Mayer <markus.mayer@linaro.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Conflicts: drivers/tty/serial/8250/8250_dw.c
2014-06-20Staging: speakup: Update __speakup_paste_selection() tty (ab)usage to match vtBen Hutchings
commit 28a821c306889b9f2c3fff49abedc9b2c743eb73 upstream. This function is largely a duplicate of paste_selection() in drivers/tty/vt/selection.c, but with its own selection state. The speakup selection mechanism should really be merged with vt. For now, apply the changes from 'TTY: vt, fix paste_selection ldisc handling', 'tty: Make ldisc input flow control concurrency-friendly', and 'tty: Fix unsafe vt paste_selection()'. References: https://bugs.debian.org/735202 References: https://bugs.debian.org/744015 Reported-by: Paul Gevers <elbrus@debian.org> Reported-and-tested-by: Jarek Czekalski <jarekczek@poczta.onet.pl> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-06-068250_core: Fix unwanted TX chars writeLoic Poulain
commit b08c9c317e3f7764a91d522cd031639ba42b98cc upstream. On transmit-hold-register empty, serial8250_tx_chars should be called only if we don't use DMA. DMA has its own tx cycle. Signed-off-by: Loic Poulain <loic.poulain@intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-06-06serial: 8250: Fix thread unsafe __dma_tx_complete functionLoic Poulain
commit f8fd1b0350d3a4581125f5eda6528f5a2c5f9183 upstream. __dma_tx_complete is not protected against concurrent call of serial8250_tx_dma. it can lead to circular tail index corruption or parallel call of serial_tx_dma on the same data portion. This patch fixes this issue by holding the port lock. Signed-off-by: Loic Poulain <loic.poulain@intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-15n_tty: Fix n_tty_write crash when echoing in raw modePeter Hurley
commit 4291086b1f081b869c6d79e5b7441633dc3ace00 upstream. The tty atomic_write_lock does not provide an exclusion guarantee for the tty driver if the termios settings are LECHO & !OPOST. And since it is unexpected and not allowed to call TTY buffer helpers like tty_insert_flip_string concurrently, this may lead to crashes when concurrect writers call pty_write. In that case the following two writers: * the ECHOing from a workqueue and * pty_write from the process race and can overflow the corresponding TTY buffer like follows. If we look into tty_insert_flip_string_fixed_flag, there is: int space = __tty_buffer_request_room(port, goal, flags); struct tty_buffer *tb = port->buf.tail; ... memcpy(char_buf_ptr(tb, tb->used), chars, space); ... tb->used += space; so the race of the two can result in something like this: A B __tty_buffer_request_room __tty_buffer_request_room memcpy(buf(tb->used), ...) tb->used += space; memcpy(buf(tb->used), ...) ->BOOM B's memcpy is past the tty_buffer due to the previous A's tb->used increment. Since the N_TTY line discipline input processing can output concurrently with a tty write, obtain the N_TTY ldisc output_lock to serialize echo output with normal tty writes. This ensures the tty buffer helper tty_insert_flip_string is not called concurrently and everything is fine. Note that this is nicely reproducible by an ordinary user using forkpty and some setup around that (raw termios + ECHO). And it is present in kernels at least after commit d945cb9cce20ac7143c2de8d88b187f62db99bdc (pty: Rework the pty layer to use the normal buffering logic) in 2.6.31-rc3. js: add more info to the commit log js: switch to bool js: lock unconditionally js: lock only the tty->ops->write call References: CVE-2014-0196 Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-15tty: Fix lockless tty buffer racePeter Hurley
commit 62a0d8d7c2b29f92850e4ee3c38e5dfd936e92b2 upstream. Commit 6a20dbd6caa2358716136144bf524331d70b1e03, "tty: Fix race condition between __tty_buffer_request_room and flush_to_ldisc" correctly identifies an unsafe race condition between __tty_buffer_request_room() and flush_to_ldisc(), where the consumer flush_to_ldisc() prematurely advances the head before consuming the last of the data committed. For example: CPU 0 | CPU 1 __tty_buffer_request_room | flush_to_ldisc ... | ... | count = head->commit - head->read n = tty_buffer_alloc() | b->commit = b->used | b->next = n | | if (!count) /* T */ | if (head->next == NULL) /* F */ | buf->head = head->next In this case, buf->head has been advanced but head->commit may have been updated with a new value. Instead of reintroducing an unnecessary lock, fix the race locklessly. Read the commit-next pair in the reverse order of writing, which guarantees the commit value read is the latest value written if the head is advancing. Reported-by: Manfred Schlaegl <manfred.schlaegl@gmx.at> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-15tty: serial: 8250_core.c Bug fix for Exar chips.Michael Welling
commit b790f210fe8423eff881b2a8a93ba5dbc45534d0 upstream. The sleep function was updated to put the serial port to sleep only when necessary. This appears to resolve the errant behavior of the driver as described in Kernel Bug 61961 – "My Exar Corp. XR17C/D152 Dual PCI UART modem does not work with 3.8.0". Signed-off-by: Michael Welling <mwelling@ieee.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-15drivers/tty/hvc: don't free hvc_console_setup after initTomoki Sekiyama
commit 501fed45b7e8836ee9373f4d31e2d85e3db6103a upstream. When 'console=hvc0' is specified to the kernel parameter in x86 KVM guest, hvc console is setup within a kthread. However, that will cause SEGV and the boot will fail when the driver is builtin to the kernel, because currently hvc_console_setup() is annotated with '__init'. This patch removes '__init' to boot the guest successfully with 'console=hvc0'. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-15hvc: ensure hvc_init is only ever called once in hvc_console.cPaul Gortmaker
commit f76a1cbed18c86e2d192455f0daebb48458965f3 upstream. Commit 3e6c6f630a5282df8f3393a59f10eb9c56536d23 ("Delay creation of khcvd thread") moved the call of hvc_init from being a device_initcall into hvc_alloc, and used a non-null hvc_driver as indication of whether hvc_init had already been called. The problem with this is that hvc_driver is only assigned a value at the bottom of hvc_init, and so there is a window where multiple hvc_alloc calls can be in progress at the same time and hence try and call hvc_init multiple times. Previously the use of device_init guaranteed that hvc_init was only called once. This manifests itself as sporadic instances of two hvc_init calls racing each other, and with the loser of the race getting -EBUSY from tty_register_driver() and hence that virtual console fails: Couldn't register hvc console driver virtio-ports vport0p1: error -16 allocating hvc for port Here we add an atomic_t to guarantee we'll never run hvc_init twice. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 3e6c6f630a52 ("Delay creation of khcvd thread") Reported-by: Jim Somerville <Jim.Somerville@windriver.com> Tested-by: Jim Somerville <Jim.Somerville@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-05tty: Fix low_latency BUGPeter Hurley
commit a9c3f68f3cd8d55f809fbdb0c138ed061ea1bd25 upstream. The user-settable knob, low_latency, has been the source of several BUG reports which stem from flush_to_ldisc() running in interrupt context. Since 3.12, which added several sleeping locks (termios_rwsem and buf->lock) to the input processing path, the frequency of these BUG reports has increased. Note that changes in 3.12 did not introduce this regression; sleeping locks were first added to the input processing path with the removal of the BKL from N_TTY in commit a88a69c91256418c5907c2f1f8a0ec0a36f9e6cc, 'n_tty: Fix loss of echoed characters and remove bkl from n_tty' and later in commit 38db89799bdf11625a831c5af33938dcb11908b6, 'tty: throttling race fix'. Since those changes, executing flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe. However, since most devices do not validate if the low_latency setting is appropriate for the context (process or interrupt) in which they receive data, some reports are due to misconfiguration. Further, serial dma devices for which dma fails, resort to interrupt receiving as a backup without resetting low_latency. Historically, low_latency was used to force wake-up the reading process rather than wait for the next scheduler tick. The effect was to trim multiple milliseconds of latency from when the process would receive new data. Recent tests [1] have shown that the reading process now receives data with only 10's of microseconds latency without low_latency set. Remove the low_latency rx steering from tty_flip_buffer_push(); however, leave the knob as an optional hint to drivers that can tune their rx fifos and such like. Cleanup stale code comments regarding low_latency. [1] https://lkml.org/lkml/2014/2/20/434 "Yay.. thats an annoying historical pain in the butt gone." -- Alan Cox Reported-by: Beat Bolli <bbolli@ewanet.ch> Reported-by: Pavel Roskin <proski@gnu.org> Acked-by: David Sterba <dsterba@suse.cz> Cc: Grant Edwards <grant.b.edwards@gmail.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Hal Murray <murray+fedora@ip-64-139-1-69.sjc.megapath.net> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-05tty: Set correct tty name in 'active' sysfs attributeHannes Reinecke
commit 723abd87f6e536f1353c8f64f621520bc29523a3 upstream. The 'active' sysfs attribute should refer to the currently active tty devices the console is running on, not the currently active console. The console structure doesn't refer to any device in sysfs, only the tty the console is running on has. So we need to print out the tty names in 'active', not the console names. There is one special-case, which is tty0. If the console is directed to it, we want 'tty0' to show up in the file, so user-space knows that the messages get forwarded to the active VT. The ->device() callback would resolve tty0, though. Hence, treat it special and don't call into the VT layer to resolve it (plymouth is known to depend on it). Cc: Lennart Poettering <lennart@poettering.net> Cc: Kay Sievers <kay@vrfy.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Werner Fink <werner@suse.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-02-22vt: Fix secure clear screenPetr Písař
commit 0930b0950a8996aa88b0d2ba4bb2bab27cc36bc7 upstream. \E[3J console code (secure clear screen) needs to update_screen(vc) in order to write-through blanks into off-screen video memory. This has been removed accidentally in 3.6 by: commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c Author: Jean-François Moine <moinejf@free.fr> Date: Thu Sep 6 19:24:13 2012 +0200 tty vt: Fix line garbage in virtual console on command line edition Signed-off-by: Petr Písař <petr.pisar@atlas.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-22tty: n_gsm: Fix for modems with brk in modem status controlLars Poeschel
commit 3ac06b905655b3ef2fd2196bab36e4587e1e4e4f upstream. 3GPP TS 07.10 states in section 5.4.6.3.7: "The length byte contains the value 2 or 3 ... depending on the break signal." The break byte is optional and if it is sent, the length is 3. In fact the driver was not able to work with modems that send this break byte in their modem status control message. If the modem just sends the break byte if it is really set, then weird things might happen. The code for deconding the modem status to the internal linux presentation in gsm_process_modem has already a big comment about this 2 or 3 byte length thing and it is already able to decode the brk, but the code calling the gsm_process_modem function in gsm_control_modem does not encode it and hand it over the right way. This patch fixes this. Without this fix if the modem sends the brk byte in it's modem status control message the driver will hang when opening a muxed channel. Signed-off-by: Lars Poeschel <poeschel@lemonage.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-22serial: sirf: fix kernel panic caused by unpaired spinlockQipan Li
commit fb78b811422cd2d8c8605949cc4cc13618347ad5 upstream. commit 8b9ade9f74f8a279 coming from Viresh Kumar "tty: serial: sirfsoc: drop uart_port->lock before calling tty_flip_buffer_push()" broke sirfsoc uart driver by knic: [ 5.129122] BUG: spinlock already unlocked on CPU#0, ip6tables/1331 [ 5.132554] lock: sirfsoc_uart_ports+0x4/0x8a0, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 [ 5.141651] CPU: 0 PID: 1331 Comm: ip6tables Tainted: G W O 3.10.16 #3 [ 5.148866] [<c0013528>] (unwind_backtrace+0x0/0xe0) from [<c0010e70>] (show_stack+0x10/0x14) [ 5.157362] [<c0010e70>] (show_stack+0x10/0x14) from [<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8) [ 5.166125] [<c01a5e68>] (do_raw_spin_unlock+0x40/0xc8) from [<c03ff8b4>] (_raw_spin_unlock+0x8/0x40) [ 5.175322] [<c03ff8b4>] (_raw_spin_unlock+0x8/0x40) from [<c0203fcc>] (sirfsoc_uart_pio_rx_chars+0xa4/0xc0) [ 5.185120] [<c0203fcc>] (sirfsoc_uart_pio_rx_chars+0xa4/0xc0) from [<c0204fb8>] (sirfsoc_rx_tmo_process_tl+0xdc/0x1e0) [ 5.195875] [<c0204fb8>] (sirfsoc_rx_tmo_process_tl+0xdc/0x1e0) from [<c0024b50>] (tasklet_action+0x8c/0xec) [ 5.205673] [<c0024b50>] (tasklet_action+0x8c/0xec) from [<c00242a8>] (__do_softirq+0xec/0x1d4) [ 5.214347] [<c00242a8>] (__do_softirq+0xec/0x1d4) from [<c0024428>] (do_softirq+0x48/0x54) [ 5.222674] [<c0024428>] (do_softirq+0x48/0x54) from [<c0024690>] (irq_exit+0x74/0xc0) [ 5.230573] [<c0024690>] (irq_exit+0x74/0xc0) from [<c000e1e8>] (handle_IRQ+0x6c/0x90) [ 5.238465] [<c000e1e8>] (handle_IRQ+0x6c/0x90) from [<c000d500>] (__irq_svc+0x40/0x70) [ 5.246446] [<c000d500>] (__irq_svc+0x40/0x70) from [<c0092e7c>] (mark_page_accessed+0xc/0x68) [ 5.255034] [<c0092e7c>] (mark_page_accessed+0xc/0x68) from [<c00a2a4c>] (unmap_single_vma+0x3bc/0x550) [ 5.264402] [<c00a2a4c>] (unmap_single_vma+0x3bc/0x550) from [<c00a3b4c>] (unmap_vmas+0x44/0x54) [ 5.273164] [<c00a3b4c>] (unmap_vmas+0x44/0x54) from [<c00a81a8>] (exit_mmap+0xc4/0x1e0) [ 5.281233] [<c00a81a8>] (exit_mmap+0xc4/0x1e0) from [<c001bb78>] (mmput+0x3c/0xdc) [ 5.288868] [<c001bb78>] (mmput+0x3c/0xdc) from [<c0021b0c>] (do_exit+0x30c/0x828) [ 5.296413] [<c0021b0c>] (do_exit+0x30c/0x828) from [<c0022dac>] (do_group_exit+0x4c/0xb0) [ 5.304653] [<c0022dac>] (do_group_exit+0x4c/0xb0) from [<c0022e20>] (__wake_up_parent+0x0/0x18) Root cause: the commit dropped uart_port->lock before calling tty_flip_buffer_push(), but in sirfsoc-uart, sirfsoc_uart_pio_rx_chars() can be called by sirfsoc_rx_tmo_process_tl(). here uart_port->lock has not been taken yet. so that caused unpaired lock/unlock. Solution: This patch is doing a quick fix for that, it adds spin_lock/unlock(&port->lock) protect to sirfsoc_uart_pio_rx_chars() in sirfsoc_rx_tmo_process_tl() to keep spin_lock/unlock in pair. Signed-off-by: Qipan Li <Qipan.Li@csr.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06serial: 8250: enable UART_BUG_NOMSR for TegraStephen Warren
commit 3685f19e07802ec4207b52465c408f185b66490e upstream. Tegra chips have 4 or 5 identical UART modules embedded. UARTs C..E have their MODEM-control signals tied off to a static state. However UARTs A and B can optionally route those signals to/from package pins, depending on the exact pinmux configuration. When these signals are not routed to package pins, false interrupts may trigger either temporarily, or permanently, all while not showing up in the IIR; it will read as NO_INT. This will eventually lead to the UART IRQ being disabled due to unhandled interrupts. When this happens, the kernel may print e.g.: irq 68: nobody cared (try booting with the "irqpoll" option) In order to prevent this, enable UART_BUG_NOMSR. This prevents UART_IER_MSI from being enabled, which prevents the false interrupts from triggering. In practice, this is not needed under any of the following conditions: * On Tegra chips after Tegra30, since the HW bug has apparently been fixed. * On UARTs C..E since their MODEM control signals are tied to the correct static state which doesn't trigger the issue. * On UARTs A..B if the MODEM control signals are routed out to package pins, since they will then carry valid signals. However, we ignore these exceptions for now, since they are only relevant if a board actually hooks up more than a 4-wire UART, and no currently supported board does this. If we ever support a board that does, we can refine the algorithm that enables UART_BUG_NOMSR to take those exceptions into account, and/or read a flag from DT/... that indicates that the board has hooked up and pinmux'd more than a 4-wire UART. Reported-by: Olof Johansson <olof@lixom.net> # autotester Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06serial: 8250: Fix initialisation of Quatech cards with the AMCC PCI chipJonathan Woithe
commit 9c5320f8d7d9a2cf623e65d50e1113f34d9b9eb1 upstream. Fix the initialisation of older Quatech serial cards which are fitted with the AMCC PCI Matchmaker interface chip. Signed-off-by: Jonathan Woithe (jwoithe@just42.net) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06serial: add support for 200 v3 series Titan cardYegor Yefremov
commit 48c0247d7b7bf58abb85a39021099529df365c4d upstream. Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06tty/serial: at91: disable uart timer at start of shutdownMarek Roszko
commit 8bc661bfc0c2d221e209f4205bdaaf574d50100c upstream. The uart timer will schedule a tasklet when it fires. It is possible that it can fire inside _shutdown before it is killed in the dma and pdc cleanup routines. This causes a tasklet that exists after the port is shutdown, so when the kernel finally executes it, it panics as the tty port is NULL. This is a somewhat rare condition but its possible if a program keeps on opening/closing the port. It has been observed in particular with systemd boot messages that were causing a kernel panic because of this behavior. Moving the timer deletion to the beginning of the function stops a tasklet from being scheduled unexpectedly. Signed-off-by: Marek Roszko <mark.roszko@gmail.com> [nicolas.ferre@atmel.com: modify commit message, call setup_timer() in any case] Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06tty/serial: at91: reset rx_ring when port is shutdownMark Deneen
commit bb7e73c598fb226c75f7625088a8f6a45a0fc892 upstream. When using RX DMA, the driver won't pass any data to the uart layer until the buffer is flipped. When the port is shutdown, the dma buffers are unmapped, but the head and tail of the ring buffer are not reseted. Since the serial console will keep the port open, this will only present itself when the uart is not shared. To reproduce the issue, with an unpatched driver, run a getty on /dev/ttyS0 with no serial console and exit. Getty will exit, and when the new one returns you will be unable to log in. If you hold down a key long enough to fill the DMA buffer and flip it, you can then log in. Signed-off-by: Mark Deneen <mdeneen@gmail.com> Acked-by: Leilei Zhao <leilei.zhao@atmel.com> [nicolas.ferre@atmel.com: adapt to mainline kernel, handle !DMA case] Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06tty/serial: at91: fix race condition in atmel_serial_removeMarek Roszko
commit f50c995f9ebf064cea1368bf361c4e29679415b4 upstream. The _remove callback could be called when a tasklet is scheduled. tasklet_kill was called inside the function in order to free up any scheduled tasklets. However it was called after uart_remove_one_port which destroys tty references needed in the port for atmel_tasklet_func. Simply putting the tasklet_kill at the start of the function will prevent this conflict. Signed-off-by: Marek Roszko <mark.roszko@gmail.com> Acked-by: Leilei Zhao <leilei.zhao@atmel.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-06tty/serial: at91: Handle shutdown more safelyMarek Roszko
commit 0cc7c6c7916b1b6f34350ff1473b80b9f7e459c0 upstream. Interrupts were being cleaned up late in the shutdown handler, it is possible that an interrupt can occur and schedule a tasklet that runs after the port is cleaned up. There is a null dereference due to this race condition with the following stacktrace: [<c02092b0>] (atmel_tasklet_func+0x514/0x814) from [<c001fd34>] (tasklet_action+0x70/0xa8) [<c001fd34>] (tasklet_action+0x70/0xa8) from [<c001f60c>] (__do_softirq+0x90/0x144) [<c001f60c>] (__do_softirq+0x90/0x144) from [<c001fa18>] (irq_exit+0x40/0x4c) [<c001fa18>] (irq_exit+0x40/0x4c) from [<c000e298>] (handle_IRQ+0x64/0x84) [<c000e298>] (handle_IRQ+0x64/0x84) from [<c000d6c0>] (__irq_svc+0x40/0x50) [<c000d6c0>] (__irq_svc+0x40/0x50) from [<c0208060>] (atmel_rx_dma_release+0x88/0xb8) [<c0208060>] (atmel_rx_dma_release+0x88/0xb8) from [<c0209740>] (atmel_shutdown+0x104/0x160) [<c0209740>] (atmel_shutdown+0x104/0x160) from [<c0205e8c>] (uart_port_shutdown+0x2c/0x38) Signed-off-by: Marek Roszko <mark.roszko@gmail.com> Acked-by: Leilei Zhao <leilei.zhao@atmel.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-25serial: amba-pl011: use port lock to guard control register accessJon Medhurst
commit fe43390702a1b5741fdf217063b05c7612b38303 upstream. When the pl011 is being used for a console, pl011_console_write forces the control register (CR) to enable the UART for transmission and then restores this to the original value afterwards. It does this while holding the port lock. Unfortunately, when the uart is started or shutdown - say in response to userland using the serial device for a terminal - then this updates the control register without any locking. This means we can have pl011_console_write Save CR pl011_startup Initialise CR, e.g. enable receive pl011_console_write Restore old CR with receive not enabled this result is a serial port which doesn't respond to any input. A similar race in reverse could happen when the device is shutdown. We can fix these problems by taking the port lock when updating CR. Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>