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2017-04-18tty: vt, fix bogus division in csi_JJiri Slaby1-1/+1
commit 42acfc6615f47e465731c263bee0c799edb098f2 upstream. In csi_J(3), the third parameter of scr_memsetw (vc_screenbuf_size) is divided by 2 inappropriatelly. But scr_memsetw expects size, not count, because it divides the size by 2 on its own before doing actual memset-by-words. So remove the bogus division. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Petr Písař <ppisar@redhat.com> Fixes: f8df13e0a9 (tty: Clean console safely) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-24vt: clear selection before resizingScot Doyle1-0/+3
[ Upstream commit 009e39ae44f4191188aeb6dfbf661b771dbbe515 ] When resizing a vt its selection may exceed the new size, resulting in an invalid memory access [1]. Clear the selection before resizing. [1] http://lkml.kernel.org/r/CACT4Y+acDTwy4umEvf5ROBGiRJNrxHN4Cn5szCXE5Jw-d1B=Xw@mail.gmail.com Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Scot Doyle <lkml14@scotdoyle.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2016-11-24tty: limit terminal size to 4M charsDmitry Vyukov1-0/+2
[ Upstream commit 32b2921e6a7461fe63b71217067a6cf4bddb132f ] Size of kmalloc() in vc_do_resize() is controlled by user. Too large kmalloc() size triggers WARNING message on console. Put a reasonable upper bound on terminal size to prevent WARNINGs. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> CC: David Rientjes <rientjes@google.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: linux-kernel@vger.kernel.org Cc: syzkaller@googlegroups.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2016-08-22serial: samsung: Fix ERR pointer dereference on deferred probeKrzysztof Kozlowski1-3/+9
[ Upstream commit e51e4d8a185de90424b03f30181b35f29c46a25a ] When the clk_get() of "uart" clock returns EPROBE_DEFER, the next re-probe finishes with success but uses invalid (ERR_PTR) values. This leads to dereferencing of ERR_PTR stored under ourport->clk: 12c30000.serial: Controller clock not found (...) 12c30000.serial: ttySAC3 at MMIO 0x12c30000 (irq = 61, base_baud = 0) is a S3C6400/10 Unable to handle kernel paging request at virtual address fffffdfb (clk_prepare) from [<c039f7d0>] (s3c24xx_serial_pm+0x20/0x128) (s3c24xx_serial_pm) from [<c0395414>] (uart_change_pm+0x38/0x40) (uart_change_pm) from [<c039689c>] (uart_add_one_port+0x31c/0x44c) (uart_add_one_port) from [<c03a035c>] (s3c24xx_serial_probe+0x2a8/0x418) (s3c24xx_serial_probe) from [<c03ee110>] (platform_drv_probe+0x50/0xb0) (platform_drv_probe) from [<c03ecb44>] (driver_probe_device+0x1f4/0x2b0) (driver_probe_device) from [<c03eb0c0>] (bus_for_each_drv+0x44/0x8c) (bus_for_each_drv) from [<c03ec8c8>] (__device_attach+0x9c/0x100) (__device_attach) from [<c03ebf54>] (bus_probe_device+0x84/0x8c) (bus_probe_device) from [<c03ec388>] (deferred_probe_work_func+0x60/0x8c) (deferred_probe_work_func) from [<c012fee4>] (process_one_work+0x120/0x328) (process_one_work) from [<c0130150>] (worker_thread+0x2c/0x4ac) (worker_thread) from [<c0135320>] (kthread+0xd8/0xf4) (kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c) The first unsuccessful clk_get() causes s3c24xx_serial_init_port() to exit with failure but the s3c24xx_uart_port is left half-configured (e.g. port->mapbase is set, clk contains ERR_PTR). On next re-probe, the function s3c24xx_serial_init_port() will exit early with success because of configured port->mapbase and driver will use old values, including the ERR_PTR as clock. Fix this by cleaning the port->mapbase on error path so each re-probe will initialize all of the port settings. Fixes: 60e93575476f ("serial: samsung: enable clock before clearing pending interrupts during init") Cc: <stable@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Tested-by: Javier Martinez Canillas <javier@osg.samsung.com> Tested-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2016-08-08tty/vt/keyboard: fix OOB access in do_compute_shiftstate()Dmitry Torokhov1-21/+9
[ Upstream commit 510cccb5b0c8868a2b302a0ab524da7912da648b ] The size of individual keymap in drivers/tty/vt/keyboard.c is NR_KEYS, which is currently 256, whereas number of keys/buttons in input device (and therefor in key_down) is much larger - KEY_CNT - 768, and that can cause out-of-bound access when we do sym = U(key_maps[0][k]); with large 'k'. To fix it we should not attempt iterating beyond smaller of NR_KEYS and KEY_CNT. Also while at it let's switch to for_each_set_bit() instead of open-coding it. Reported-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2016-07-12serial: samsung: Reorder the sequence of clock control when call ↵Chanwoo Choi1-2/+2
s3c24xx_serial_set_termios() [ Upstream commit b8995f527aac143e83d3900ff39357651ea4e0f6 ] This patch fixes the broken serial log when changing the clock source of uart device. Before disabling the original clock source, this patch enables the new clock source to protect the clock off state for a split second. Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-07-12tty: vt, return error when con_startup failsJiri Slaby1-2/+3
[ Upstream commit 6798df4c5fe0a7e6d2065cf79649a794e5ba7114 ] When csw->con_startup() fails in do_register_con_driver, we return no error (i.e. 0). This was changed back in 2006 by commit 3e795de763. Before that we used to return -ENODEV. So fix the return value to be -ENODEV in that case again. Fixes: 3e795de763 ("VT binding: Add binding/unbinding support for the VT console") Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: "Dan Carpenter" <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-07-128250: use callbacks to access UART_DLL/UART_DLMSebastian Frias1-12/+6
[ Upstream commit 0b41ce991052022c030fd868e03877700220b090 ] Some UART HW has a single register combining UART_DLL/UART_DLM (this was probably forgotten in the change that introduced the callbacks, commit b32b19b8ffc05cbd3bf91c65e205f6a912ca15d9) Fixes: b32b19b8ffc0 ("[SERIAL] 8250: set divisor register correctly ...") Signed-off-by: Sebastian Frias <sf84@laposte.net> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-06-03QE-UART: add "fsl,t1040-ucc-uart" to of_device_idZhao Qiang1-0/+3
[ Upstream commit 11ca2b7ab432eb90906168c327733575e68d388f ] New bindings use "fsl,t1040-ucc-uart" as the compatible for qe-uart. So add it. Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-06-03TTY: n_gsm, fix false positive WARN_ONJiri Slaby1-1/+3
[ Upstream commit d175feca89a1c162f60f4e3560ca7bc9437c65eb ] Dmitry reported, that the current cleanup code in n_gsm can trigger a warning: WARNING: CPU: 2 PID: 24238 at drivers/tty/n_gsm.c:2048 gsm_cleanup_mux+0x166/0x6b0() ... Call Trace: ... [<ffffffff81247ab9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:490 [<ffffffff828d0456>] gsm_cleanup_mux+0x166/0x6b0 drivers/tty/n_gsm.c:2048 [<ffffffff828d4d87>] gsmld_open+0x5b7/0x7a0 drivers/tty/n_gsm.c:2386 [<ffffffff828b9078>] tty_ldisc_open.isra.2+0x78/0xd0 drivers/tty/tty_ldisc.c:447 [<ffffffff828b973a>] tty_set_ldisc+0x1ca/0xa70 drivers/tty/tty_ldisc.c:567 [< inline >] tiocsetd drivers/tty/tty_io.c:2650 [<ffffffff828a14ea>] tty_ioctl+0xb2a/0x2140 drivers/tty/tty_io.c:2883 ... But this is a legal path when open fails to find a space in the gsm_mux array and tries to clean up. So make it a standard test instead of a warning. Reported-by: "Dmitry Vyukov" <dvyukov@google.com> Cc: Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/r/CACT4Y+bHQbAB68VFi7Romcs-Z9ZW3kQRvcq+BvHH1oa5NcAdLA@mail.gmail.com Fixes: 5a640967 ("tty/n_gsm.c: fix a memory leak in gsmld_open()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-03-02pty: make sure super_block is still valid in final /dev/tty closeHerton R. Krzesinski1-3/+6
[ Upstream commit 1f55c718c290616889c04946864a13ef30f64929 ] Considering current pty code and multiple devpts instances, it's possible to umount a devpts file system while a program still has /dev/tty opened pointing to a previosuly closed pty pair in that instance. In the case all ptmx and pts/N files are closed, umount can be done. If the program closes /dev/tty after umount is done, devpts_kill_index will use now an invalid super_block, which was already destroyed in the umount operation after running ->kill_sb. This is another "use after free" type of issue, but now related to the allocated super_block instance. To avoid the problem (warning at ida_remove and potential crashes) for this specific case, I added two functions in devpts which grabs additional references to the super_block, which pty code now uses so it makes sure the super block structure is still valid until pty shutdown is done. I also moved the additional inode references to the same functions, which also covered similar case with inode being freed before /dev/tty final close/shutdown. Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Cc: stable@vger.kernel.org # 2.6.29+ Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-03-02pty: fix possible use after free of tty->driver_dataHerton R. Krzesinski1-1/+17
[ Upstream commit 2831c89f42dcde440cfdccb9fee9f42d54bbc1ef ] This change fixes a bug for a corner case where we have the the last release from a pty master/slave coming from a previously opened /dev/tty file. When this happens, the tty->driver_data can be stale, due to all ptmx or pts/N files having already been closed before (and thus the inode related to these files, which tty->driver_data points to, being already freed/destroyed). The fix here is to keep a reference on the opened master ptmx inode. We maintain the inode referenced until the final pty_unix98_shutdown, and only pass this inode to devpts_kill_index. Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Cc: <stable@vger.kernel.org> # 2.6.29+ Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-03-02tty: Add support for PCIe WCH382 2S multi-IO cardJeremy McNicoll1-1/+21
[ Upstream commit 7dde55787b43a8f2b4021916db38d90c03a2ec64 ] WCH382 2S board is a PCIe card with 2 DB9 COM ports detected as Serial controller: Device 1c00:3253 (rev 10) (prog-if 05 [16850]) Signed-off-by: Jeremy McNicoll <jmcnicol@redhat.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-03-02tty: Add support for the WCH384 4S multi-IO cardSergej Pupykin1-3/+26
[ Upstream commit 72a3c0e4e6624a77ee6eee0903f209185fe20647 ] WCH384 4S board is a PCI-E card with 4 DB9 COM ports detected as Serial controller: Device 1c00:3470 (rev 10) (prog-if 05 [16850]) Signed-off-by: Sergej Pupykin <ml@sergej.pp.ru> Acked-by: Zany Yan <sirlight@cox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-03-02parport: Add support for the WCH382 2S/1P multi-IO cardSergej Pupykin1-0/+21
[ Upstream commit 2fdd8c8c5304901fa7dbb2ce5dbc90a1984cee3d ] WCH382 is a PCI-E card with 1 LPT and 2 DB9 COM ports detected as Serial controller: Device 1c00:3250 (rev 10) (prog-if 05 [16850]) Signed-off-by: Sergej Pupykin <ml@sergej.pp.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-02-15serial: 8250_pci: Add Intel Broadwell portsMika Westerberg1-0/+29
[ Upstream commit 6c55d9b98335f7f6bd5f061866ff1633401f3a44 ] Some recent (early 2015) macbooks have Intel Broadwell where LPSS UARTs are PCI enumerated instead of ACPI. The LPSS UART block is pretty much same as used on Intel Baytrail so we can reuse the existing Baytrail setup code. Add both Broadwell LPSS UART ports to the list of supported devices. Signed-off-by: Leif Liddy <leif.liddy@gmail.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-02-15n_tty: Fix unsafe reference to "other" ldiscPeter Hurley1-5/+2
[ Upstream commit 6d27a63caad3f13e96cf065d2d96828c2006be6b ] Although n_tty_check_unthrottle() has a valid ldisc reference (since the tty core gets the ldisc ref in tty_read() before calling the line discipline read() method), it does not have a valid ldisc reference to the "other" pty of a pty pair. Since getting an ldisc reference for tty->link essentially open-codes tty_wakeup(), just replace with the equivalent tty_wakeup(). Cc: <stable@vger.kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2016-02-15tty: Fix unsafe ldisc reference via ioctl(TIOCGETD)Peter Hurley1-1/+23
[ Upstream commit 5c17c861a357e9458001f021a7afa7aab9937439 ] ioctl(TIOCGETD) retrieves the line discipline id directly from the ldisc because the line discipline id (c_line) in termios is untrustworthy; userspace may have set termios via ioctl(TCSETS*) without actually changing the line discipline via ioctl(TIOCSETD). However, directly accessing the current ldisc via tty->ldisc is unsafe; the ldisc ptr dereferenced may be stale if the line discipline is changing via ioctl(TIOCSETD) or hangup. Wait for the line discipline reference (just like read() or write()) to retrieve the "current" line discipline id. Cc: <stable@vger.kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-11-15serial: 8250_pci: Add support for 12 port Exar boardsSoeren Grunewald1-0/+21
[ Upstream commit be32c0cf0462c36f482b5ddcff1d8371be1e183c ] The Exar XR17V358 can also be combined with a XR17V354 chip to act as a single 12 port chip. This works the same way as the combining two XR17V358 chips. But the reported device id then is 0x4358. Signed-off-by: Soeren Grunewald <soeren.grunewald@desy.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-11-15serial: 8250_pci: Add support for 16 port Exar boardsSoeren Grunewald1-2/+23
[ Upstream commit 96a5d18bc1338786fecac73599f1681f59a59a8e ] The Exar XR17V358 chip usually provides only 8 ports. But two chips can be combined to act as a single 16 port chip. Therefor one chip is configured as master the second as slave by connecting the mode pin to VCC (master) or GND (slave). Then the master chip is reporting a different device-id depending on whether a slave is detected or not. The UARTs 8-15 are addressed from 0x2000-0x3fff. So the offset of 0x400 from UART to UART can be used to address all 16 ports as before. See: https://www.exar.com/common/content/document.ashx?id=1587 page 11 Signed-off-by: Soeren Grunewald <soeren.grunewald@desy.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-31tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.cKosuke Tatsukawa1-10/+5
[ Upstream commit e81107d4c6bd098878af9796b24edc8d4a9524fd ] My colleague ran into a program stall on a x86_64 server, where n_tty_read() was waiting for data even if there was data in the buffer in the pty. kernel stack for the stuck process looks like below. #0 [ffff88303d107b58] __schedule at ffffffff815c4b20 #1 [ffff88303d107bd0] schedule at ffffffff815c513e #2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818 #3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2 #4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23 #5 [ffff88303d107dd0] tty_read at ffffffff81368013 #6 [ffff88303d107e20] __vfs_read at ffffffff811a3704 #7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57 #8 [ffff88303d107f00] sys_read at ffffffff811a4306 #9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7 There seems to be two problems causing this issue. First, in drivers/tty/n_tty.c, __receive_buf() stores the data and updates ldata->commit_head using smp_store_release() and then checks the wait queue using waitqueue_active(). However, since there is no memory barrier, __receive_buf() could return without calling wake_up_interactive_poll(), and at the same time, n_tty_read() could start to wait in wait_woken() as in the following chart. __receive_buf() n_tty_read() ------------------------------------------------------------------------ if (waitqueue_active(&tty->read_wait)) /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ add_wait_queue(&tty->read_wait, &wait); ... if (!input_available_p(tty, 0)) { smp_store_release(&ldata->commit_head, ldata->read_head); ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ The second problem is that n_tty_read() also lacks a memory barrier call and could also cause __receive_buf() to return without calling wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken() as in the chart below. __receive_buf() n_tty_read() ------------------------------------------------------------------------ spin_lock_irqsave(&q->lock, flags); /* from add_wait_queue() */ ... if (!input_available_p(tty, 0)) { /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ smp_store_release(&ldata->commit_head, ldata->read_head); if (waitqueue_active(&tty->read_wait)) __add_wait_queue(q, wait); spin_unlock_irqrestore(&q->lock,flags); /* from add_wait_queue() */ ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ There are also other places in drivers/tty/n_tty.c which have similar calls to waitqueue_active(), so instead of adding many memory barrier calls, this patch simply removes the call to waitqueue_active(), leaving just wake_up*() behind. This fixes both problems because, even though the memory access before or after the spinlocks in both wake_up*() and add_wait_queue() can sneak into the critical section, it cannot go past it and the critical section assures that they will be serialized (please see "INTER-CPU ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a better explanation). Moreover, the resulting code is much simpler. Latency measurement using a ping-pong test over a pty doesn't show any visible performance drop. Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-31Revert "tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c"Sasha Levin1-6/+10
This reverts commit af32cc7bde6304dac92e6a74fe4b2cc8120cb29a. The commit was incorrectly backported and was causing hangs. Reported-by: Corey Wright <undefined@pobox.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-28serial: 8250: don't bind to SMSC IrCC IR portMaciej S. Szmigiero1-0/+5
[ Upstream commit ffa34de03bcfbfa88d8352942bc238bb48e94e2d ] SMSC IrCC SIR/FIR port should not be bound to by (legacy) serial driver so its own driver (smsc-ircc2) can bind to it. Signed-off-by: Maciej Szmigiero <mail@maciej.szmigiero.name> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-28tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.cKosuke Tatsukawa1-10/+6
[ Upstream commit e81107d4c6bd098878af9796b24edc8d4a9524fd ] My colleague ran into a program stall on a x86_64 server, where n_tty_read() was waiting for data even if there was data in the buffer in the pty. kernel stack for the stuck process looks like below. #0 [ffff88303d107b58] __schedule at ffffffff815c4b20 #1 [ffff88303d107bd0] schedule at ffffffff815c513e #2 [ffff88303d107bf0] schedule_timeout at ffffffff815c7818 #3 [ffff88303d107ca0] wait_woken at ffffffff81096bd2 #4 [ffff88303d107ce0] n_tty_read at ffffffff8136fa23 #5 [ffff88303d107dd0] tty_read at ffffffff81368013 #6 [ffff88303d107e20] __vfs_read at ffffffff811a3704 #7 [ffff88303d107ec0] vfs_read at ffffffff811a3a57 #8 [ffff88303d107f00] sys_read at ffffffff811a4306 #9 [ffff88303d107f50] entry_SYSCALL_64_fastpath at ffffffff815c86d7 There seems to be two problems causing this issue. First, in drivers/tty/n_tty.c, __receive_buf() stores the data and updates ldata->commit_head using smp_store_release() and then checks the wait queue using waitqueue_active(). However, since there is no memory barrier, __receive_buf() could return without calling wake_up_interactive_poll(), and at the same time, n_tty_read() could start to wait in wait_woken() as in the following chart. __receive_buf() n_tty_read() ------------------------------------------------------------------------ if (waitqueue_active(&tty->read_wait)) /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ add_wait_queue(&tty->read_wait, &wait); ... if (!input_available_p(tty, 0)) { smp_store_release(&ldata->commit_head, ldata->read_head); ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ The second problem is that n_tty_read() also lacks a memory barrier call and could also cause __receive_buf() to return without calling wake_up_interactive_poll(), and n_tty_read() to wait in wait_woken() as in the chart below. __receive_buf() n_tty_read() ------------------------------------------------------------------------ spin_lock_irqsave(&q->lock, flags); /* from add_wait_queue() */ ... if (!input_available_p(tty, 0)) { /* Memory operations issued after the RELEASE may be completed before the RELEASE operation has completed */ smp_store_release(&ldata->commit_head, ldata->read_head); if (waitqueue_active(&tty->read_wait)) __add_wait_queue(q, wait); spin_unlock_irqrestore(&q->lock,flags); /* from add_wait_queue() */ ... timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout); ------------------------------------------------------------------------ There are also other places in drivers/tty/n_tty.c which have similar calls to waitqueue_active(), so instead of adding many memory barrier calls, this patch simply removes the call to waitqueue_active(), leaving just wake_up*() behind. This fixes both problems because, even though the memory access before or after the spinlocks in both wake_up*() and add_wait_queue() can sneak into the critical section, it cannot go past it and the critical section assures that they will be serialized (please see "INTER-CPU ACQUIRING BARRIER EFFECTS" in Documentation/memory-barriers.txt for a better explanation). Moreover, the resulting code is much simpler. Latency measurement using a ping-pong test over a pty doesn't show any visible performance drop. Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-07-12tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_sendNicolas Ferre1-5/+2
[ Upstream commit 8687634b7908c42eb700e0469e110e02833611d1 ] In RS485 mode, we may want to set the delay_rts_after_send value to 0. In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but this is exactly the expected behavior if we want no delay... Moreover, if the value was set to non-zero value by device-tree or earlier ioctl command, it was impossible to change it back to zero. Reported-by: Sami Pietikäinen <Sami.Pietikainen@wapice.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: stable@vger.kernel.org # 3.2+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-07-03serial: imx: Fix DMA handling for IDLE condition abortsPhilipp Zabel1-0/+8
[ Upstream commit 392bceedb107a3dc1d4287e63d7670d08f702feb ] The driver configures the IDLE condition to interrupt the SDMA engine. Since the SDMA UART ROM script doesn't clear the IDLE bit itself, this caused repeated 1-byte DMA transfers, regardless of available data in the RX FIFO. Also, when returning due to the IDLE condition, the UART ROM script already increased its counter, causing residue to be off by one. This patch clears the IDLE condition to avoid repeated 1-byte DMA transfers and decreases count by when the DMA transfer was aborted due to the IDLE condition, fixing serial transfers using DMA on i.MX6Q. Reported-by: Peter Seiderer <ps.report@gmx.net> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-07-03n_tty: Fix auditing support for cannonical modeLaura Abbott1-3/+14
[ Upstream commit 72586c6061ab8c23ffd9f301ed19782a44ff5f04 ] Commit 32f13521ca68bc624ff6effc77f308a52b038bf0 ("n_tty: Line copy to user buffer in canonical mode") changed cannonical mode copying to use copy_to_user but missed adding the call to the audit framework. Add in the appropriate functions to get audit support. Fixes: 32f13521ca68 ("n_tty: Line copy to user buffer in canonical mode") Reported-by: Miloslav Trmač <mitr@redhat.com> Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-06-28serial: 8250_dw: add support for AMD SOC CarrizoKen Xue1-0/+1
[ Upstream commit 5ef86b74209db33c133b5f18738dd8f3189b63a1 ] Add ACPI identifier for UART on AMD SOC Carrizo. Signed-off-by: Ken Xue <Ken.Xue@amd.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-06-28serial: 8250: add support for ACPI-probed serial port for X-Gene platformFeng Kan1-0/+11
[ Upstream commit 5e1aeea52f6a0763e79473b1767401fda88eb7e1 ] Enable APM X-Gene SoC serial port functionality when using ACPI table to initialize serial port. Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-06-28serial: imx: Fix clearing of receiver overrun flagUwe Kleine-König1-5/+3
[ Upstream commit 91555ce9012557b2d621d7b0b6ec694218a2a9bc ] The writeable bits in the USR2 register are all "write 1 to clear" so only write the bits that actually should be cleared. Fixes: f1f836e4209e ("serial: imx: Add Rx Fifo overrun error message") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-06-28serial: imx: Enable UCR4_OREN in startup interfaceJiada Wang1-7/+8
[ Upstream commit 6f026d6b7cb6e019b6352ed7fb71497c787fd6d7 ] Other than enable Receiver Overrun Interrupt Enable (UCR4_OREN) in start_tx interface, UCR4_OREN should be enabled before enable of Receiver. Signed-off-by: Jiada Wang <jiada_wang@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-06-10tty/n_gsm.c: fix a memory leak when gsmtty is removedPan Xinhui1-3/+2
[ Upstream commit 8f9cfeed3eae86c70d3b04445a6f2036b27b6304 ] when gsmtty_remove put dlci, it will cause memory leak if dlci->port's refcount is zero. So we do the cleanup work in .cleanup callback instead. dlci will be last put in two call chains. 1) gsmld_close -> gsm_cleanup_mux -> gsm_dlci_release -> dlci_put 2) gsmld_remove -> dlci_put so there is a race. the memory leak depends on the race. In call chain 2. we hit the memory leak. below comment tells. release_tty -> tty_driver_remove_tty -> gsmtty_remove -> dlci_put -> tty_port_destructor (WARN_ON(port->itty) and return directly) | tty->port->itty = NULL; | tty_kref_put ---> release_one_tty -> gsmtty_cleanup (added by our patch) So our patch fix the memory leak by doing the cleanup work after tty core did. Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com> Fixes: dfabf7ffa30585 Cc: stable <stable@vger.kernel.org> # 3.14+ Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-06-09xen/events: don't bind non-percpu VIRQs with percpu chipDavid Vrabel1-1/+1
[ Upstream commit 77bb3dfdc0d554befad58fdefbc41be5bc3ed38a ] A non-percpu VIRQ (e.g., VIRQ_CONSOLE) may be freed on a different VCPU than it is bound to. This can result in a race between handle_percpu_irq() and removing the action in __free_irq() because handle_percpu_irq() does not take desc->lock. The interrupt handler sees a NULL action and oopses. Only use the percpu chip/handler for per-CPU VIRQs (like VIRQ_TIMER). # cat /proc/interrupts | grep virq 40: 87246 0 xen-percpu-virq timer0 44: 0 0 xen-percpu-virq debug0 47: 0 20995 xen-percpu-virq timer1 51: 0 0 xen-percpu-virq debug1 69: 0 0 xen-dyn-virq xen-pcpu 74: 0 0 xen-dyn-virq mce 75: 29 0 xen-dyn-virq hvc_console Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: <stable@vger.kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-05-23xen/console: Update console event channel on resumeBoris Ostrovsky1-1/+17
[ Upstream commit b9d934f27c91b878c4b2e64299d6e419a4022f8d ] 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> Cc: <stable@vger.kernel.org> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-05-18tty/serial: at91: maxburst was missing for dma transfersLudovic Desroches1-0/+2
[ Upstream commit a8d4e01637902311c5643b69a5c80e2805f04054 ] 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> Cc: <stable@vger.kernel.org> # 3.12 and later Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-05-18serial: xilinx: Use platform_get_irq to get irq description structureMichal Simek2-11/+12
[ Upstream commit 5c90c07b98c02198d9777a7c4f3047b0a94bf7ed ] For systems with CONFIG_SERIAL_OF_PLATFORM=y and device_type = "serial"; property in DT of_serial.c driver maps and unmaps IRQ (because driver probe fails). Then a driver is called but irq mapping is not created that's why driver is failing again in again on request_irq(). Based on this use platform_get_irq() instead of platform_get_resource() which is doing irq_desc allocation and driver itself can request IRQ. Fix both xilinx serial drivers in the tree. Signed-off-by: Michal Simek <michal.simek@xilinx.com> CC: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-05-18serial: of-serial: Remove device_type = "serial" registrationMichal Simek1-1/+0
[ Upstream commit 6befa9d883385c580369a2cc9e53fbf329771f6d ] 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> CC: <stable@vger.kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-04-25tty: serial: fsl_lpuart: clear receive flag on FIFO flushStefan Agner1-0/+3
[ Upstream commit 8e4934c6d6c659e22b1b746af4196683e77ce6ca ] 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> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-04-25tty: serial: fsl_lpuart: specify transmit FIFO sizeStefan Agner1-0/+2
[ Upstream commit 4e8f245937091b2c9eebf3d4909c9ceda4f0a78e ] Specify transmit FIFO size which might be different depending on LPUART instance. This makes sure uart_wait_until_sent in serial core getting called, which in turn waits and checks if the FIFO is really empty on shutdown by using the tx_empty callback. Without the call of this callback, the last several characters might not yet be transmitted when closing the serial port. This can be reproduced by simply using echo and redirect the output to a ttyLP device. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-04-23n_tty: Fix read buffer overwrite when no newlinePeter Hurley1-27/+79
[ Upstream commit fb5ef9e7da39968fec6d6f37f20a23d23740c75e ] BugLink: http://bugs.launchpad.net/bugs/1381005 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (backported from commit fb5ef9e7da39968fec6d6f37f20a23d23740c75e) Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
2015-03-28Change email address for 8250_pciRussell King1-1/+1
[ Upstream commit f2e0ea861117bda073d1d7ffbd3120c07c0d5d34 ] I'm still receiving reports to my email address, so let's point this at the linux-serial mailing list instead. Cc: <stable@vger.kernel.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-03-28serial: 8250_dw: Fix deadlock in LCR workaroundPeter Hurley1-2/+8
[ Upstream commit 7fd6f640f2dd17dac6ddd6702c378cb0bb9cfa11 ] Trying to write console output from within the serial console driver while the port->lock is held causes recursive deadlock: CPU 0 spin_lock_irqsave(&port->lock) printk() console_unlock() call_console_drivers() serial8250_console_write() spin_lock_irqsave(&port->lock) ** DEADLOCK ** The 8250_dw i/o accessors try to write a console error message if the LCR workaround was unsuccessful. When the port->lock is already held (eg., when called from serial8250_set_termios()), this deadlocks. Make the error message a FIXME until a general solution is devised. Cc: Tim Kryger <tim.kryger@gmail.com> Reported-by: Zhang Zhen <zhenzhang.zhang@huawei.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-03-14serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is ↵Sebastian Andrzej Siewior1-6/+5
something in the FIFO" commit ca8bb4aefb932e3da105f28cbfba36d57a931081 upstream. This reverts commit 0aa525d11859c1a4d5b78fdc704148e2ae03ae13. The conditional RX-FIFO read seems to cause spurious interrupts and we see just: |serial8250: too much work for irq29 The previous behaviour was "default" for decades and Marvell's 88f6282 SoC might not be the only that relies on it. Therefore the Omap fix is reverted for now. Fixes: 0aa525d11859 ("tty: serial: 8250_core: read only RX if there is something in the FIFO") Reported-By: Nicolas Schichan <nschichan@freebox.fr> Debuged-By: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-03-14tty: fix up atime/mtime mess, take fourJiri Slaby1-2/+2
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-03-14TTY: fix tty_wait_until_sent on 64-bit machinesJohan Hovold1-3/+9
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: Sasha Levin <sasha.levin@oracle.com>
2015-03-07serial: fsl_lpuart: avoid new transfer while DMA is runningStefan Agner1-4/+5
commit 5f1437f61a0b351d25b528c159360da3d5e8c77b upstream. When the UART is in DMA receive mode (RDMAS set) and one character just arrived while another interrupt is handled (e.g. TX), the RDRF (receiver data register full flag) is set due to the water level of 1. But since the DMA will take care of this character, there is no need to handle it by calling lpuart_prepare_rx. Handling it leads to adding the RX timeout timer twice: [ 74.336698] Kernel BUG at 80053070 [verbose debug info unavailable] [ 74.342999] Internal error: Oops - BUG: 0 [#1] ARM0:00.00 khungtaskd [ 74.347817] Modules linked in: 0 S 0.0 0.0 0:00.00 writeback [ 74.350926] CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc3-00001-g39d78e2 #1788 [ 74.358617] Hardware name: Freescale Vybrid VF610 (Device Tree)t [ 74.364563] task: 807a7678 ti: 8079c000 task.ti: 8079c000 kblockd [ 74.370002] PC is at add_timer+0x24/0x28.0 0.0 0:00.09 kworker/u2:1 [ 74.373960] LR is at lpuart_int+0x15c/0x3d8 [ 74.378171] pc : [<80053070>] lr : [<802e0d88>] psr: a0010193 [ 74.378171] sp : 8079de10 ip : 8079de20 fp : 8079de1c [ 74.389694] r10: 807d44c0 r9 : 8688c300 r8 : 00000013 [ 74.394943] r7 : 20010193 r6 : 00000000 r5 : 000000a0 r4 : 86997210 [ 74.401498] r3 : ffffa7da r2 : 80817868 r1 : 86997210 r0 : 86997344 [ 74.408052] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 74.415489] Control: 10c5387d Table: 8611c059 DAC: 00000015 [ 74.421265] Process swapper (pid: 0, stack limit = 0x8079c230) ... Solve this by only execute the receiver path (lpuart_prepare_rx) if the DMA receive mode (RDMAS) is not set. Also, make sure the flag is cleared on initialization, in case it has been left set. This can be best reproduced using UART as a serial console, then running top while dd'ing data into the terminal. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07serial: fsl_lpuart: delete timer on shutdownStefan Agner1-3/+4
commit 4a8588a1cf867333187d9ff071e6fbdab587d194 upstream. If the serial port gets closed while a RX transfer is in progress, the timer might fire after the serial port shutdown finished. This leads in a NULL pointer dereference: [ 7.508324] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 7.516590] pgd = 86348000 [ 7.519445] [00000000] *pgd=86179831, *pte=00000000, *ppte=00000000 [ 7.526145] Internal error: Oops: 17 [#1] ARM [ 7.530611] Modules linked in: [ 7.533876] CPU: 0 PID: 123 Comm: systemd Not tainted 3.19.0-rc3-00004-g5b11ea7 #1778 [ 7.541827] Hardware name: Freescale Vybrid VF610 (Device Tree) [ 7.547862] task: 861c3400 ti: 86ac8000 task.ti: 86ac8000 [ 7.553392] PC is at lpuart_timer_func+0x24/0xf8 [ 7.558127] LR is at lpuart_timer_func+0x20/0xf8 [ 7.562857] pc : [<802df99c>] lr : [<802df998>] psr: 600b0113 [ 7.562857] sp : 86ac9b90 ip : 86ac9b90 fp : 86ac9bbc [ 7.574467] r10: 80817180 r9 : 80817b98 r8 : 80817998 [ 7.579803] r7 : 807acee0 r6 : 86989000 r5 : 00000100 r4 : 86997210 [ 7.586444] r3 : 86ac8000 r2 : 86ac9bc0 r1 : 86997210 r0 : 00000000 [ 7.593085] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 7.600341] Control: 10c5387d Table: 86348059 DAC: 00000015 [ 7.606203] Process systemd (pid: 123, stack limit = 0x86ac8230) Setup the timer on UART startup which allows to delete the timer unconditionally on shutdown. This also saves the initialization on each transfer. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07vt: provide notifications on selection changesNicolas Pitre1-1/+3
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07tty/serial: at91: fix error handling in atmel_serial_probe()Cyrille Pitchen1-1/+3
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07tty: Prevent untrappable signals from malicious programPeter Hurley1-0/+3
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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