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2018-05-22tty: Use __GFP_NOFAIL for tty_ldisc_get()Tetsuo Handa
[ Upstream commit bcdd0ca8cb8730573afebcaae4138f8f4c8eaa20 ] syzbot is reporting crashes triggered by memory allocation fault injection at tty_ldisc_get() [1]. As an attempt to handle OOM in a graceful way, we have tried commit 5362544bebe85071 ("tty: don't panic on OOM in tty_set_ldisc()"). But we reverted that attempt by commit a8983d01f9b7d600 ("Revert "tty: don't panic on OOM in tty_set_ldisc()"") due to reproducible crash. We should spend resource for finding and fixing race condition bugs rather than complicate error paths for 2 * sizeof(void *) bytes allocation failure. [1] https://syzkaller.appspot.com/bug?id=489d33fa386453859ead58ff5171d43772b13aa3 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+40b7287c2dc987c48c81@syzkaller.appspotmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22tty: n_gsm: Fix DLCI handling for ADM mode if debug & 2 is not setTony Lindgren
[ Upstream commit b2d89ad9c9682e795ed6eeb9ed455789ad6cedf1 ] At least on droid 4 with control channel in ADM mode, there is no response to Modem Status Command (MSC). Currently gsmtty_modem_update() expects to have data in dlci->modem_rx unless debug & 2 is set. This means that on droid 4, things only work if debug & 2 is set. Let's fix the issue by ignoring empty dlci->modem_rx for ADM mode. In the AMD mode, CMD_MSC will never respond and gsm_process_modem() won't get called to set dlci->modem_rx. And according to ts_127010v140000p.pdf, MSC is only relevant if basic option is chosen, so let's test for that too. Fixes: ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for control dlci") Cc: linux-serial@vger.kernel.org Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: Dan Williams <dcbw@redhat.com> Cc: Jiri Prchal <jiri.prchal@aksignal.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Marcel Partap <mpartap@gmx.net> Cc: Merlijn Wajer <merlijn@wizzup.org> Cc: Michael Nazzareno Trimarchi <michael@amarulasolutions.com> Cc: Michael Scott <michael.scott@linaro.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Russ Gorby <russ.gorby@intel.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Sebastian Reichel <sre@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22tty: n_gsm: Fix long delays with control frame timeouts in ADM modeTony Lindgren
[ Upstream commit e9ec22547986dd32c5c70da78107ce35dbff1344 ] Commit ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for control dlci") added support for DLCI to stay in Asynchronous Disconnected Mode (ADM). But we still get long delays waiting for commands to other DLCI to complete: --> 5) C: SABM(P) Q> 0) C: UIH(F) Q> 0) C: UIH(F) Q> 0) C: UIH(F) ... This happens because gsm_control_send() sets cretries timer to T2 that is by default set to 34. This will cause resend for T2 times for the control frame. In ADM mode, we will never get a response so the control frame, so retries are just delaying all the commands. Let's fix the issue by setting DLCI_MODE_ADM flag after detecting the ADM mode for the control DLCI. Then we can use that in gsm_control_send() to set retries to 1. This means the control frame will be sent once allowing the other end at an opportunity to switch from ADM to ABM mode. Note that retries will be decremented in gsm_control_retransmit() so we don't want to set it to 0 here. Fixes: ea3d8465ab9b ("tty: n_gsm: Allow ADM response in addition to UA for control dlci") Cc: linux-serial@vger.kernel.org Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: Dan Williams <dcbw@redhat.com> Cc: Jiri Prchal <jiri.prchal@aksignal.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Marcel Partap <mpartap@gmx.net> Cc: Merlijn Wajer <merlijn@wizzup.org> Cc: Michael Nazzareno Trimarchi <michael@amarulasolutions.com> Cc: Michael Scott <michael.scott@linaro.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Russ Gorby <russ.gorby@intel.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Sebastian Reichel <sre@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22tty: Don't call panic() at tty_ldisc_init()Tetsuo Handa
[ Upstream commit 903f9db10f18f735e62ba447147b6c434b6af003 ] syzbot is reporting kernel panic [1] triggered by memory allocation failure at tty_ldisc_get() from tty_ldisc_init(). But since both tty_ldisc_get() and caller of tty_ldisc_init() can cleanly handle errors, tty_ldisc_init() does not need to call panic() when tty_ldisc_get() failed. [1] https://syzkaller.appspot.com/bug?id=883431818e036ae6a9981156a64b821110f39187 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22tty: make n_tty_read() always abort if hangup is in progressTejun Heo
[ Upstream commit 28b0f8a6962a24ed21737578f3b1b07424635c9e ] A tty is hung up by __tty_hangup() setting file->f_op to hung_up_tty_fops, which is skipped on ttys whose write operation isn't tty_write(). This means that, for example, /dev/console whose write op is redirected_tty_write() is never actually marked hung up. Because n_tty_read() uses the hung up status to decide whether to abort the waiting readers, the lack of hung-up marking can lead to the following scenario. 1. A session contains two processes. The leader and its child. The child ignores SIGHUP. 2. The leader exits and starts disassociating from the controlling terminal (/dev/console). 3. __tty_hangup() skips setting f_op to hung_up_tty_fops. 4. SIGHUP is delivered and ignored. 5. tty_ldisc_hangup() is invoked. It wakes up the waits which should clear the read lockers of tty->ldisc_sem. 6. The reader wakes up but because tty_hung_up_p() is false, it doesn't abort and goes back to sleep while read-holding tty->ldisc_sem. 7. The leader progresses to tty_ldisc_lock() in tty_ldisc_hangup() and is now stuck in D sleep indefinitely waiting for tty->ldisc_sem. The following is Alan's explanation on why some ttys aren't hung up. http://lkml.kernel.org/r/20171101170908.6ad08580@alans-desktop 1. It broke the serial consoles because they would hang up and close down the hardware. With tty_port that *should* be fixable properly for any cases remaining. 2. The console layer was (and still is) completely broken and doens't refcount properly. So if you turn on console hangups it breaks (as indeed does freeing consoles and half a dozen other things). As neither can be fixed quickly, this patch works around the problem by introducing a new flag, TTY_HUPPING, which is used solely to tell n_tty_read() that hang-up is in progress for the console and the readers should be aborted regardless of the hung-up status of the device. The following is a sample hung task warning caused by this issue. INFO: task agetty:2662 blocked for more than 120 seconds. Not tainted 4.11.3-dbg-tty-lockup-02478-gfd6c7ee-dirty #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 0 2662 1 0x00000086 Call Trace: __schedule+0x267/0x890 schedule+0x36/0x80 schedule_timeout+0x23c/0x2e0 ldsem_down_write+0xce/0x1f6 tty_ldisc_lock+0x16/0x30 tty_ldisc_hangup+0xb3/0x1b0 __tty_hangup+0x300/0x410 disassociate_ctty+0x6c/0x290 do_exit+0x7ef/0xb00 do_group_exit+0x3f/0xa0 get_signal+0x1b3/0x5d0 do_signal+0x28/0x660 exit_to_usermode_loop+0x46/0x86 do_syscall_64+0x9c/0xb0 entry_SYSCALL64_slow_path+0x25/0x25 The following is the repro. Run "$PROG /dev/console". The parent process hangs in D state. #include <sys/types.h> #include <sys/stat.h> #include <sys/wait.h> #include <sys/ioctl.h> #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <signal.h> #include <time.h> #include <termios.h> int main(int argc, char **argv) { struct sigaction sact = { .sa_handler = SIG_IGN }; struct timespec ts1s = { .tv_sec = 1 }; pid_t pid; int fd; if (argc < 2) { fprintf(stderr, "test-hung-tty /dev/$TTY\n"); return 1; } /* fork a child to ensure that it isn't already the session leader */ pid = fork(); if (pid < 0) { perror("fork"); return 1; } if (pid > 0) { /* top parent, wait for everyone */ while (waitpid(-1, NULL, 0) >= 0) ; if (errno != ECHILD) perror("waitpid"); return 0; } /* new session, start a new session and set the controlling tty */ if (setsid() < 0) { perror("setsid"); return 1; } fd = open(argv[1], O_RDWR); if (fd < 0) { perror("open"); return 1; } if (ioctl(fd, TIOCSCTTY, 1) < 0) { perror("ioctl"); return 1; } /* fork a child, sleep a bit and exit */ pid = fork(); if (pid < 0) { perror("fork"); return 1; } if (pid > 0) { nanosleep(&ts1s, NULL); printf("Session leader exiting\n"); exit(0); } /* * The child ignores SIGHUP and keeps reading from the controlling * tty. Because SIGHUP is ignored, the child doesn't get killed on * parent exit and the bug in n_tty makes the read(2) block the * parent's control terminal hangup attempt. The parent ends up in * D sleep until the child is explicitly killed. */ sigaction(SIGHUP, &sact, NULL); printf("Child reading tty\n"); while (1) { char buf[1024]; if (read(fd, buf, sizeof(buf)) < 0) { perror("read"); return 1; } } return 0; } Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22tty: n_gsm: Allow ADM response in addition to UA for control dlciTony Lindgren
[ Upstream commit ea3d8465ab9b3e01be329ac5195970a84bef76c5 ] Some devices have the control dlci stay in ADM mode instead of the UA mode. This can seen at least on droid 4 when trying to open the ts 27.010 mux port. Enabling n_gsm debug mode shows the control dlci always respond with DM to SABM instead of UA: # modprobe n_gsm debug=0xff # ldattach -d GSM0710 /dev/ttyS0 & gsmld_output: 00000000: f9 03 3f 01 1c f9 --> 0) C: SABM(P) gsmld_receive: 00000000: f9 03 1f 01 36 f9 <-- 0) C: DM(P) ... $ minicom -D /dev/gsmtty1 minicom: cannot open /dev/gsmtty1: No error information $ strace minicom -D /dev/gsmtty1 ... open("/dev/gsmtty1", O_RDWR|O_NOCTTY|O_NONBLOCK|O_LARGEFILE) = -1 EL2HLT Note that this is different issue from other n_gsm -EL2HLT issues such as timeouts when the control dlci does not respond at all. The ADM mode seems to be a quite common according to "RF Wireless World" article "GSM Issue-UE sends SABM and gets a DM response instead of UA response": This issue is most commonly observed in GSM networks where in UE sends SABM and expects network to send UA response but it ends up receiving DM response from the network. SABM stands for Set asynchronous balanced mode, UA stands for Unnumbered Acknowledge and DA stands for Disconnected Mode. An RLP entity can be in one of two modes: - Asynchronous Balanced Mode (ABM) - Asynchronous Disconnected Mode (ADM) Currently Linux kernel closes the control dlci after several retries in gsm_dlci_t1() on DM. This causes n_gsm /dev/gsmtty ports to produce error code -EL2HLT when trying to open them as the closing of control dlci has already set gsm->dead. Let's fix the issue by allowing control dlci stay in ADM mode after the retries so the /dev/gsmtty ports can be opened and used. It seems that it might take several attempts to get any response from the control dlci, so it's best to allow ADM mode only after the SABM retries are done. Note that for droid 4 additional patches are needed to mux the ttyS0 pins and to toggle RTS gpio_149 to wake up the mdm6600 modem are also needed to use n_gsm. And the mdm6600 modem needs to be powered on. Cc: linux-serial@vger.kernel.org Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: Jiri Prchal <jiri.prchal@aksignal.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Marcel Partap <mpartap@gmx.net> Cc: Michael Scott <michael.scott@linaro.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Russ Gorby <russ.gorby@intel.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Sebastian Reichel <sre@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22Fix serial console on SNI RM400 machinesThomas Bogendoerfer
[ Upstream commit e279e6d98e0cf2c2fe008b3c29042b92f0e17b1d ] sccnxp driver doesn't get the correct uart clock rate, if CONFIG_HAVE_CLOCK is disabled. Correct usage of clk API to make it work with/without it. Fixes: 90efa75f7ab0 (serial: sccnxp: Using CLK API for getting UART clock) Suggested-by: Russell King - ARM Linux <linux@armlinux.org.uk> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22serial: 8250: omap: Disable DMA for console UARTVignesh R
[ Upstream commit 84b40e3b57eef1417479c00490dd4c9f6e5ffdbc ] Kernel always writes log messages to console via serial8250_console_write()->serial8250_console_putchar() which directly accesses UART_TX register _without_ using DMA. But, if other processes like systemd using same UART port, then these writes are handled by a different code flow using 8250_omap driver where there is provision to use DMA. It seems that it is possible that both DMA and CPU might simultaneously put data to UART FIFO and lead to potential loss of data due to FIFO overflow and weird data corruption. This happens when both kernel console and userspace tries to write simultaneously to the same UART port. Therefore, disable DMA on kernel console port to avoid potential race between CPU and DMA. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22vt: change SGR 21 to follow the standardsMike Frysinger
[ Upstream commit 65d9982d7e523a1a8e7c9af012da0d166f72fc56 ] ECMA-48 [1] (aka ISO 6429) has defined SGR 21 as "doubly underlined" since at least March 1984. The Linux kernel has treated it as SGR 22 "normal intensity" since it was added in Linux-0.96b in June 1992. Before that, it was simply ignored. Other terminal emulators have either ignored it, or treat it as double underline now. xterm for example added support in its 304 release (May 2014) [2] where it was previously ignoring it. Changing this behavior shouldn't be an issue: - It isn't a named capability in ncurses's terminfo database, so no script is using libtinfo/libcurses to look this up, or using tput to query & output the right sequence. - Any script assuming SGR 21 will reset intensity in all terminals already do not work correctly on non-Linux VTs (including running under screen/tmux/etc...). - If someone has written a script that only runs in the Linux VT, and they're using SGR 21 (instead of SGR 22), the output should still be readable. imo it's important to change this as the Linux VT's non-conformance is sometimes used as an argument for other terminal emulators to not implement SGR 21 at all, or do so incorrectly. [1]: https://www.ecma-international.org/publications/standards/Ecma-048.htm [2]: https://github.com/ThomasDickey/xterm-snapshots/commit/2fd29cb98d214cb536bcafbee00bc73b3f1eeb9d Signed-off-by: Mike Frysinger <vapier@chromium.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-05-22tty: vt: fix up tabstops properlyLinus Torvalds
[ Upstream commit f1869a890cdedb92a3fab969db5d0fd982850273 ] Tabs on a console with long lines do not wrap properly, so correctly account for the line length when computing the tab placement location. Reported-by: James Holderness <j4_james@hotmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-03-20serial: 8250_pci: Add Brainboxes UC-260 4 port serial deviceNikola Ciprich
[ Upstream commit 9f2068f35729948bde84d87a40d135015911345d ] Add PCI ids for two variants of Brainboxes UC-260 quad port PCI serial cards. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-03-20tty/serial: atmel: add new version check for usartJonas Danielsson
[ Upstream commit fd63a8903a2c40425a9811c3371dd4d0f42c0ad3 ] On our at91sam9260 based board the usart0 and usart1 ports report their versions (ATMEL_US_VERSION) as 0x10302. This version is not included in the current checks in the driver. Signed-off-by: Jonas Danielsson <jonas@orbital-systems.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-03-20serial: sh-sci: prevent lockup on full TTY buffersUlrich Hecht
[ Upstream commit 7842055bfce4bf0170d0f61df8b2add8399697be ] When the TTY buffers fill up to the configured maximum, a system lockup occurs: [ 598.820128] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 598.825796] 0-...!: (1 GPs behind) idle=5a6/2/0 softirq=1974/1974 fqs=1 [ 598.832577] (detected by 3, t=62517 jiffies, g=296, c=295, q=126) [ 598.838755] Task dump for CPU 0: [ 598.841977] swapper/0 R running task 0 0 0 0x00000022 [ 598.849023] Call trace: [ 598.851476] __switch_to+0x98/0xb0 [ 598.854870] (null) This can be prevented by doing a dummy read of the RX data register. This issue affects both HSCIF and SCIF ports. Reported for R-Car H3 ES2.0; reproduced and fixed on H3 ES1.1. Probably affects other R-Car platforms as well. Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable <stable@vger.kernel.org> Tested-by: Nguyen Viet Dung <dung.nguyen.aj@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-03-04tty: cyclades: cyz_interrupt is only used for PCIArnd Bergmann
[ Upstream commit 05ead49691d245f67bdd1b30cab5d9af522ac884 ] When CONFIG_PCI is not set, enabling CONFIG_CYZ_INTR has no practical effect other than generating a warning about an unused function: drivers/tty/cyclades.c:1184:20: warning: 'cyz_interrupt' defined but not used [-Wunused-function] static irqreturn_t cyz_interrupt(int irq, void *dev_id) This adds a dependency to avoid that warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-03-04tty: hvc_xen: hide xen_console_remove when unusedArnd Bergmann
[ Upstream commit e36ae3439936e13c33f5841c7c2c1a9875acbb6d ] xencons_disconnect_backend() is only called from xen_console_remove(), which is conditionally compiled, so we get a harmless warning when CONFIG_HVC_XEN_FRONTEND is unset: hvc/hvc_xen.c:350:12: error: 'xen_console_remove' defined but not used [-Werror=unused-function] This moves the function down into the same #ifdef section to silence the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-02-28sysrq: Fix warning in sysrq generated crash.Ani Sinha
[ Upstream commit 984cf355aeaa8f2eda3861b50d0e8d3e3f77e83b ] Commit 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") replaced spin_lock_irqsave() calls with rcu_read_lock() calls in sysrq. Since rcu_read_lock() does not disable preemption, faulthandler_disabled() in __do_page_fault() in x86/fault.c returns false. When the code later calls might_sleep() in the pagefault handler, we get the following warning: BUG: sleeping function called from invalid context at ../arch/x86/mm/fault.c:1187 in_atomic(): 0, irqs_disabled(): 0, pid: 4706, name: bash Preemption disabled at:[<ffffffff81484339>] printk+0x48/0x4a To fix this, we release the RCU read lock before we crash. Tested this patch on linux 3.18 by booting off one of our boards. Fixes: 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") Signed-off-by: Ani Sinha <ani@arista.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-02-28n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD)Linus Torvalds
[ Upstream commit 966031f340185eddd05affcf72b740549f056348 ] We added support for EXTPROC back in 2010 in commit 26df6d13406d ("tty: Add EXTPROC support for LINEMODE") and the intent was to allow it to override some (all?) ICANON behavior. Quoting from that original commit message: There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. but the problem turns out that "several aspects of the terminal driver are disabled" is a bit ambiguous, and you can really confuse the n_tty layer by setting EXTPROC and then causing some of the ICANON invariants to no longer be maintained. This fixes at least one such case (TIOCINQ) becoming unhappy because of the confusion over whether ICANON really means ICANON when EXTPROC is set. This basically makes TIOCINQ match the case of read: if EXTPROC is set, we ignore ICANON. Also, make sure to reset the ICANON state ie EXTPROC changes, not just if ICANON changes. Fixes: 26df6d13406d ("tty: Add EXTPROC support for LINEMODE") Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by: syzkaller <syzkaller@googlegroups.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-01-17sysrq : fix Show Regs call trace on ARMJibin Xu
[ Upstream commit b00bebbc301c8e1f74f230dc82282e56b7e7a6db ] When kernel configuration SMP,PREEMPT and DEBUG_PREEMPT are enabled, echo 1 >/proc/sys/kernel/sysrq echo p >/proc/sysrq-trigger kernel will print call trace as below: sysrq: SysRq : Show Regs BUG: using __this_cpu_read() in preemptible [00000000] code: sh/435 caller is __this_cpu_preempt_check+0x18/0x20 Call trace: [<ffffff8008088e80>] dump_backtrace+0x0/0x1d0 [<ffffff8008089074>] show_stack+0x24/0x30 [<ffffff8008447970>] dump_stack+0x90/0xb0 [<ffffff8008463950>] check_preemption_disabled+0x100/0x108 [<ffffff8008463998>] __this_cpu_preempt_check+0x18/0x20 [<ffffff80084c9194>] sysrq_handle_showregs+0x1c/0x40 [<ffffff80084c9c7c>] __handle_sysrq+0x12c/0x1a0 [<ffffff80084ca140>] write_sysrq_trigger+0x60/0x70 [<ffffff8008251e00>] proc_reg_write+0x90/0xd0 [<ffffff80081f1788>] __vfs_write+0x48/0x90 [<ffffff80081f241c>] vfs_write+0xa4/0x190 [<ffffff80081f3354>] SyS_write+0x54/0xb0 [<ffffff80080833f0>] el0_svc_naked+0x24/0x28 This can be seen on a common board like an r-pi3. This happens because when echo p >/proc/sysrq-trigger, get_irq_regs() is called outside of IRQ context, if preemption is enabled in this situation,kernel will print the call trace. Since many prior discussions on the mailing lists have made it clear that get_irq_regs either just returns NULL or stale data when used outside of IRQ context,we simply avoid calling it outside of IRQ context. Signed-off-by: Jibin Xu <jibin.xu@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-01-17serial: 8250_fintek: Fix rs485 disablement on invalid ioctl()Lukas Wunner
[ Upstream commit 3236a965486ba0c6043cf2c7b51943d8b382ae29 ] This driver's ->rs485_config callback checks if SER_RS485_RTS_ON_SEND and SER_RS485_RTS_AFTER_SEND have the same value. If they do, it means the user has passed in invalid data with the TIOCSRS485 ioctl() since RTS must have a different polarity when sending and when not sending. In this case, rs485 mode is not enabled (the RS485_URA bit is not set in the RS485 Enable Register) and this is supposed to be signaled back to the user by clearing the SER_RS485_ENABLED bit in struct serial_rs485 ... except a missing tilde character is preventing that from happening. Fixes: 28e3fb6c4dce ("serial: Add support for Fintek F81216A LPC to 4 UART") Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Cc: "Ji-Ze Hong (Peter Hong)" <hpeter@gmail.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-01-17serial: 8250_pci: Add Amazon PCI serial device IDMatt Wilson
[ Upstream commit 3bfd1300abfe3adb18e84a89d97a0e82a22124bb ] This device will be used in future Amazon EC2 instances as the primary serial port (i.e., data sent to this port will be available via the GetConsoleOuput [1] EC2 API). [1] http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_GetConsoleOutput.html Cc: stable <stable@vger.kernel.org> Signed-off-by: Matt Wilson <msw@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-01-178250_pci: Fix potential use-after-free in error pathGabriel Krisman Bertazi
[ Upstream commit c130b666a9a711f985a0a44b58699ebe14bb7245 ] Commit f209fa03fc9d ("serial: 8250_pci: Detach low-level driver during PCI error recovery") introduces a potential use-after-free in case the pciserial_init_ports call in serial8250_io_resume fails, which may happen if a memory allocation fails or if the .init quirk failed for whatever reason). If this happen, further pci_get_drvdata will return a pointer to freed memory. This patch reworks the PCI recovery resume hook to restore the old priv structure in this case, which should be ok, since the ports were already detached. Such error during recovery causes us to give up on the recovery. Fixes: f209fa03fc9d ("serial: 8250_pci: Detach low-level driver during PCI error recovery") Reported-by: Michal Suchanek <msuchanek@suse.com> Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-01-17serial: 8250_pci: Detach low-level driver during PCI error recoverySumit Semwal
[ Upstream commit f209fa03fc9d131b3108c2e4936181eabab87416 ] During a PCI error recovery, like the ones provoked by EEH in the ppc64 platform, all IO to the device must be blocked while the recovery is completed. Current 8250_pci implementation only suspends the port instead of detaching it, which doesn't prevent incoming accesses like TIOCMGET and TIOCMSET calls from reaching the device. Those end up racing with the EEH recovery, crashing it. Similar races were also observed when opening the device and when shutting it down during recovery. This patch implements a more robust IO blockage for the 8250_pci recovery by unregistering the port at the beginning of the procedure and re-adding it afterwards. Since the port is detached from the uart layer, we can be sure that no request will make through to the device during recovery. This is similar to the solution used by the JSM serial driver. I thank Peter Hurley <peter@hurleysoftware.com> for valuable input on this one over one year ago. Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-01-17tty: n_hdlc: get rid of racy n_hdlc.tbufAlexander Popov
[ Upstream commit 82f2341c94d270421f383641b7cd670e474db56b ] Currently N_HDLC line discipline uses a self-made singly linked list for data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after an error. The commit be10eb7589337e5defbe214dae038a53dd21add8 ("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf. After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put one data buffer to tx_free_buf_list twice. That causes double free in n_hdlc_release(). Let's use standard kernel linked list and get rid of n_hdlc.tbuf: in case of tx error put current data buffer after the head of tx_buf_list. Signed-off-by: Alexander Popov <alex.popov@linux.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2018-01-17TTY: n_hdlc, fix lockdep false positiveJiri Slaby
[ Upstream commit e9b736d88af1a143530565929390cadf036dc799 ] The class of 4 n_hdls buf locks is the same because a single function n_hdlc_buf_list_init is used to init all the locks. But since flush_tx_queue takes n_hdlc->tx_buf_list.spinlock and then calls n_hdlc_buf_put which takes n_hdlc->tx_free_buf_list.spinlock, lockdep emits a warning: ============================================= [ INFO: possible recursive locking detected ] 4.3.0-25.g91e30a7-default #1 Not tainted --------------------------------------------- a.out/1248 is trying to acquire lock: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc] but task is already holding lock: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&list->spinlock)->rlock); lock(&(&list->spinlock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by a.out/1248: #0: (&tty->ldisc_sem){++++++}, at: [<ffffffff814c9eb0>] tty_ldisc_ref_wait+0x20/0x50 #1: (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc] ... Call Trace: ... [<ffffffff81738fd0>] _raw_spin_lock_irqsave+0x50/0x70 [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc] [<ffffffffa01fdc24>] n_hdlc_tty_ioctl+0x144/0x1d0 [n_hdlc] [<ffffffff814c25c1>] tty_ioctl+0x3f1/0xe40 ... Fix it by initializing the spin_locks separately. This removes also reduntand memset of a freshly kzallocated space. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2017-12-06serial: omap: Fix EFR write on RTS deassertionLukas Wunner
[ Upstream commit 2a71de2f7366fb1aec632116d0549ec56d6a3940 ] Commit 348f9bb31c56 ("serial: omap: Fix RTS handling") sought to enable auto RTS upon manual RTS assertion and disable it on deassertion. However it seems the latter was done incorrectly, it clears all bits in the Extended Features Register *except* auto RTS. Fixes: 348f9bb31c56 ("serial: omap: Fix RTS handling") Cc: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-12-06serial: sh-sci: Fix register offsets for the IRDA serial portLaurent Pinchart
[ Upstream commit a752ba18af8285e3eeda572f40dddaebff0c3621 ] Even though most of its registers are 8-bit wide, the IRDA has two 16-bit registers that make it a 16-bit peripheral and not a 8-bit peripheral with addresses shifted by one. Fix the registers offset in the driver and the platform data regshift value. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-11-05sparc64: Migrate hvcons irq to panicked cpuVijay Kumar
[ Upstream commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd ] On panic, all other CPUs are stopped except the one which had hit panic. To keep console alive, we need to migrate hvcons irq to panicked CPU. Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-11-05tty: goldfish: Fix a parameter of a call to free_irqChristophe JAILLET
[ Upstream commit 1a5c2d1de7d35f5eb9793266237903348989502b ] 'request_irq()' and 'free_irq()' should be called with the same dev_id. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-10-03tty: fix __tty_insert_flip_char regressionArnd Bergmann
[ Upstream commit 8a5a90a2a477b86a3dc2eaa5a706db9bfdd647ca ] Sergey noticed a small but fatal mistake in __tty_insert_flip_char, leading to an oops in an interrupt handler when using any serial port. The problem is that I accidentally took the tty_buffer pointer before calling __tty_buffer_request_room(), which replaces the buffer. This moves the pointer lookup to the right place after allocating the new buffer space. Fixes: 979990c62848 ("tty: improve tty_insert_flip_char() fast path") Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-10-03tty: improve tty_insert_flip_char() slow pathArnd Bergmann
[ Upstream commit 065ea0a7afd64d6cf3464bdd1d8cd227527e2045 ] While working on improving the fast path of tty_insert_flip_char(), I noticed that by calling tty_buffer_request_room(), we needlessly move to the separate flag buffer mode for the tty, even when all characters use TTY_NORMAL as the flag. This changes the code to call __tty_buffer_request_room() with the correct flag, which will then allocate a regular buffer when it rounds out of space but no special flags have been used. I'm guessing that this is the behavior that Peter Hurley intended when he introduced the compacted flip buffers. Fixes: acc0f67f307f ("tty: Halve flip buffer GFP_ATOMIC memory consumption") Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-10-03tty: improve tty_insert_flip_char() fast pathArnd Bergmann
[ Upstream commit 979990c6284814617d8f2179d197f72ff62b5d85 ] kernelci.org reports a crazy stack usage for the VT code when CONFIG_KASAN is enabled: drivers/tty/vt/keyboard.c: In function 'kbd_keycode': drivers/tty/vt/keyboard.c:1452:1: error: the frame size of 2240 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] The problem is that tty_insert_flip_char() gets inlined many times into kbd_keycode(), and also into other functions, and each copy requires 128 bytes for stack redzone to check for a possible out-of-bounds access on the 'ch' and 'flags' arguments that are passed into tty_insert_flip_string_flags as a variable-length string. This introduces a new __tty_insert_flip_char() function for the slow path, which receives the two arguments by value. This completely avoids the problem and the stack usage goes back down to around 100 bytes. Without KASAN, this is also slightly better, as we don't have to spill the arguments to the stack but can simply pass 'ch' and 'flag' in registers, saving a few bytes in .text for each call site. This should be backported to linux-4.0 or later, which first introduced the stack sanitizer in the kernel. Cc: stable@vger.kernel.org Fixes: c420f167db8c ("kasan: enable stack instrumentation") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-07-31vt: fix unchecked __put_user() in tioclinux ioctlsAdam Borowski
[ Upstream commit 6987dc8a70976561d22450b5858fc9767788cc1c ] Only read access is checked before this call. Actually, at the moment this is not an issue, as every in-tree arch does the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU to tell them apart, but this wasn't the case in the past and may happen again on some odd arch in the future. If anyone cares about 3.7 and earlier, this is a security hole (untested) on real 80386 CPUs. Signed-off-by: Adam Borowski <kilobyte@angband.pl> CC: stable@vger.kernel.org # v3.7- Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-25serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'Christophe JAILLET
[ Upstream commit be40597a1bc173bf9dadccdf5388b956f620ae8f ] UARTn_FRAME_PARITY_ODD is 0x0300 UARTn_FRAME_PARITY_EVEN is 0x0200 So if the UART is configured for EVEN parity, it would be reported as ODD. Fix it by correctly testing if the 2 bits are set. Fixes: 3afbd89c9639 ("serial/efm32: add new driver") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-13serial: 8250_omap: Fix probe and remove for PM runtimeTony Lindgren
[ Upstream commit 4e0f5cc65098ea32a1e77baae74215b9bd5276b1 ] Otherwise the interconnect related code implementing PM runtime will produce these errors on a failed probe: omap_uart 48066000.serial: omap_device: omap_device_enable() called from invalid state 1 omap_uart 48066000.serial: use pm_runtime_put_sync_suspend() in driver? Note that we now also need to check for priv in omap8250_runtime_suspend() as it has not yet been registered if probe fails. And we need to use pm_runtime_put_sync() to properly idle the device like we already do in omap8250_remove(). Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-13tty: nozomi: avoid a harmless gcc warningArnd Bergmann
[ Upstream commit a4f642a8a3c2838ad09fe8313d45db46600e1478 ] The nozomi wireless data driver has its own helper function to transfer data from a FIFO, doing an extra byte swap on big-endian architectures, presumably to bring the data back into byte-serial order after readw() or readl() perform their implicit byteswap. This helper function is used in the receive_data() function to first read the length into a 32-bit variable, which causes a compile-time warning: drivers/tty/nozomi.c: In function 'receive_data': drivers/tty/nozomi.c:857:9: warning: 'size' may be used uninitialized in this function [-Wmaybe-uninitialized] The problem is that gcc is unsure whether the data was actually read or not. We know that it is at this point, so we can replace it with a single readl() to shut up that warning. I am leaving the byteswap in there, to preserve the existing behavior, even though this seems fishy: Reading the length of the data into a cpu-endian variable should normally not use a second byteswap on big-endian systems, unless the hardware is aware of the CPU endianess. There appears to be a lot more confusion about endianess in this driver, so it probably has not worked on big-endian systems in a long time, if ever, and I have no way to test it. It's well possible that this driver has not been used by anyone in a while, the last patch that looks like it was tested on the hardware is from 2008. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-13tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is doneRichard Genoud
[ Upstream commit b389f173aaa1204d6dc1f299082a162eb0491545 ] When using RS485 in half duplex, RX should be enabled when TX is finished, and stopped when TX starts. Before commit 0058f0871efe7b01c6 ("tty/serial: atmel: fix RS485 half duplex with DMA"), RX was not disabled in atmel_start_tx() if the DMA was used. So, collisions could happened. But disabling RX in atmel_start_tx() uncovered another bug: RX was enabled again in the wrong place (in atmel_tx_dma) instead of being enabled when TX is finished (in atmel_complete_tx_dma), so the transmission simply stopped. This bug was not triggered before commit 0058f0871efe7b01c6 ("tty/serial: atmel: fix RS485 half duplex with DMA") because RX was never disabled before. Moving atmel_start_rx() in atmel_complete_tx_dma() corrects the problem. Cc: stable@vger.kernel.org Reported-by: Gil Weber <webergil@gmail.com> Fixes: 0058f0871efe7b01c6 Tested-by: Gil Weber <webergil@gmail.com> Signed-off-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-08serial: core: fix crash in uart_suspend_portLucas Stach
[ Upstream commit 88e2582e90bb89fe895ff0dceeb5d5ab65d07997 ] With serdev we might end up with serial ports that have no cdev exported to userspace, as they are used as the bus interface to other devices. In that case serial_match_port() won't be able to find a matching tty_dev. Skip the irq wakeup enabling in that case, as serdev will make sure to keep the port active, as long as there are devices depending on it. Fixes: 8ee3fde04758 (tty_port: register tty ports with serdev bus) Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-08tty: Fix GPF in flush_to_ldisc()Peter Hurley
[ Upstream commit 9ce119f318ba1a07c29149301f1544b6c4bea52a ] A line discipline which does not define a receive_buf() method can can cause a GPF if data is ever received [1]. Oddly, this was known to the author of n_tracesink in 2011, but never fixed. [1] GPF report BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 3752d067 PUD 37a7b067 PMD 0 Oops: 0010 [#1] SMP KASAN Modules linked in: CPU: 2 PID: 148 Comm: kworker/u10:2 Not tainted 4.4.0-rc2+ #51 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: events_unbound flush_to_ldisc task: ffff88006da94440 ti: ffff88006db60000 task.ti: ffff88006db60000 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff88006db67b50 EFLAGS: 00010246 RAX: 0000000000000102 RBX: ffff88003ab32f88 RCX: 0000000000000102 RDX: 0000000000000000 RSI: ffff88003ab330a6 RDI: ffff88003aabd388 RBP: ffff88006db67c48 R08: ffff88003ab32f9c R09: ffff88003ab31fb0 R10: ffff88003ab32fa8 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88006db67c20 R14: ffffffff863df820 R15: ffff88003ab31fb8 FS: 0000000000000000(0000) GS:ffff88006dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000037938000 CR4: 00000000000006e0 Stack: ffffffff829f46f1 ffff88006da94bf8 ffff88006da94bf8 0000000000000000 ffff88003ab31fb0 ffff88003aabd438 ffff88003ab31ff8 ffff88006430fd90 ffff88003ab32f9c ffffed0007557a87 1ffff1000db6cf78 ffff88003ab32078 Call Trace: [<ffffffff8127cf91>] process_one_work+0x8f1/0x17a0 kernel/workqueue.c:2030 [<ffffffff8127df14>] worker_thread+0xd4/0x1180 kernel/workqueue.c:2162 [<ffffffff8128faaf>] kthread+0x1cf/0x270 drivers/block/aoe/aoecmd.c:1302 [<ffffffff852a7c2f>] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:468 Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff88006db67b50> CR2: 0000000000000000 ---[ end trace a587f8947e54d6ea ]--- Reported-by: Dmitry Vyukov <dvyukov@google.com> 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 <alexander.levin@verizon.com>
2017-06-08tty: fix data race in flush_to_ldiscDmitry Vyukov
[ Upstream commit 7098296a362a96051fa120abf48f0095818b99cd ] flush_to_ldisc reads port->itty and checks that it is not NULL, concurrently release_tty sets port->itty to NULL. It is possible that flush_to_ldisc loads port->itty once, ensures that it is not NULL, but then reloads it again and uses. The second load can already return NULL, which will cause a crash. Use READ_ONCE to read port->itty. The data race was found with KernelThreadSanitizer (KTSAN). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-08serial: ifx6x60: fix use-after-free on module unloadJohan Hovold
[ Upstream commit 1e948479b3d63e3ac0ecca13cbf4921c7d17c168 ] Make sure to deregister the SPI driver before releasing the tty driver to avoid use-after-free in the SPI remove callback where the tty devices are deregistered. Fixes: 72d4724ea54c ("serial: ifx6x60: Add modem power off function in the platform reboot process") Cc: stable <stable@vger.kernel.org> # 3.8 Cc: Jun Chen <jun.d.chen@intel.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-08serial: ifx6x60: Remove dangerous spi_driver castsGeert Uytterhoeven
[ Upstream commit 9a499db0325b8a8e2368f21fef66705b120f38ba ] Casting spi_driver pointers to "void *" when calling spi_{,un}register_driver() bypasses all type checking. Remove the superfluous casts to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-08Revert "tty_port: register tty ports with serdev bus"Johan Hovold
[ Upstream commit d3ba126a226a6b6da021ebfea444a2a807cde945 ] This reverts commit 8ee3fde047589dc9c201251f07d0ca1dc776feca. The new serdev bus hooked into the tty layer in tty_port_register_device() by registering a serdev controller instead of a tty device whenever a serdev client is present, and by deregistering the controller in the tty-port destructor. This is broken in several ways: Firstly, it leads to a NULL-pointer dereference whenever a tty driver later deregisters its devices as no corresponding character device will exist. Secondly, far from every tty driver uses tty-port refcounting (e.g. serial core) so the serdev devices might never be deregistered or deallocated. Thirdly, deregistering at tty-port destruction is too late as the underlying device and structures may be long gone by then. A port is not released before an open tty device is closed, something which a registered serdev client can prevent from ever happening. A driver callback while the device is gone typically also leads to crashes. Many tty drivers even keep their ports around until the driver is unloaded (e.g. serial core), something which even if a late callback never happens, leads to leaks if a device is unbound from its driver and is later rebound. The right solution here is to add a new tty_port_unregister_device() helper and to never call tty_device_unregister() whenever the port has been claimed by serdev, but since this requires modifying just about every tty driver (and multiple subsystems) it will need to be done incrementally. Reverting the offending patch is the first step in fixing the broken lifetime assumptions. A follow-up patch will add a new pair of tty-device registration helpers, which a vetted tty driver can use to support serdev (initially serial core). When every tty driver uses the serdev helpers (at least for deregistration), we can add serdev registration to tty_port_register_device() again. Note that this also fixes another issue with serdev, which currently allocates and registers a serdev controller for every tty device registered using tty_port_device_register() only to immediately deregister and deallocate it when the corresponding OF node or serdev child node is missing. This should be addressed before enabling serdev for hot-pluggable buses. Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-06-08tty_port: register tty ports with serdev busRob Herring
[ Upstream commit 8ee3fde047589dc9c201251f07d0ca1dc776feca ] Register a serdev controller with the serdev bus when a tty_port is registered. This creates the serdev controller and create's serdev devices for any DT child nodes of the tty_port's parent (i.e. the UART device). Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-By: Sebastian Reichel <sre@kernel.org> Tested-By: Sebastian Reichel <sre@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-05-17serial: omap: suspend device on probe errorsJohan Hovold
[ Upstream commit 77e6fe7fd2b7cba0bf2f2dc8cde51d7b9a35bf74 ] Make sure to actually suspend the device before returning after a failed (or deferred) probe. Note that autosuspend must be disabled before runtime pm is disabled in order to balance the usage count due to a negative autosuspend delay as well as to make the final put suspend the device synchronously. Fixes: 388bc2622680 ("omap-serial: Fix the error handling in the omap_serial probe") Cc: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Johan Hovold <johan@kernel.org> Acked-by: Tony Lindgren <tony@atomide.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>
2017-05-17serial: omap: fix runtime-pm handling on unbindJohan Hovold
[ Upstream commit 099bd73dc17ed77aa8c98323e043613b6e8f54fc ] An unbalanced and misplaced synchronous put was used to suspend the device on driver unbind, something which with a likewise misplaced pm_runtime_disable leads to external aborts when an open port is being removed. Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa024010 ... [<c046e760>] (serial_omap_set_mctrl) from [<c046a064>] (uart_update_mctrl+0x50/0x60) [<c046a064>] (uart_update_mctrl) from [<c046a400>] (uart_shutdown+0xbc/0x138) [<c046a400>] (uart_shutdown) from [<c046bd2c>] (uart_hangup+0x94/0x190) [<c046bd2c>] (uart_hangup) from [<c045b760>] (__tty_hangup+0x404/0x41c) [<c045b760>] (__tty_hangup) from [<c045b794>] (tty_vhangup+0x1c/0x20) [<c045b794>] (tty_vhangup) from [<c046ccc8>] (uart_remove_one_port+0xec/0x260) [<c046ccc8>] (uart_remove_one_port) from [<c046ef4c>] (serial_omap_remove+0x40/0x60) [<c046ef4c>] (serial_omap_remove) from [<c04845e8>] (platform_drv_remove+0x34/0x4c) Fix this up by resuming the device before deregistering the port and by suspending and disabling runtime pm only after the port has been removed. Also make sure to disable autosuspend before disabling runtime pm so that the usage count is balanced and device actually suspended before returning. Note that due to a negative autosuspend delay being set in probe, the unbalanced put would actually suspend the device on first driver unbind, while rebinding and again unbinding would result in a negative power.usage_count. Fixes: 7e9c8e7dbf3b ("serial: omap: make sure to suspend device before remove") Cc: Felipe Balbi <balbi@kernel.org> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Johan Hovold <johan@kernel.org> Acked-by: Tony Lindgren <tony@atomide.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>
2017-05-17serial: samsung: Use right device for DMA-mapping callsMarek Szyprowski
[ Upstream commit 768d64f491a530062ddad50e016fb27125f8bd7c ] Driver should provide its own struct device for all DMA-mapping calls instead of extracting device pointer from DMA engine channel. Although this is harmless from the driver operation perspective on ARM architecture, it is always good to use the DMA mapping API in a proper way. This patch fixes following DMA API debug warning: WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4 samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes] Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24) [<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0) [<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180) [<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50) [<c01395a4>] (warn_slowpath_fmt) from [<c0729058>] (check_sync+0x520/0x9f4) [<c0729058>] (check_sync) from [<c072967c>] (debug_dma_sync_single_for_device+0x88/0xc8) [<c072967c>] (debug_dma_sync_single_for_device) from [<c0803c10>] (s3c24xx_serial_start_tx_dma+0x100/0x2f8) [<c0803c10>] (s3c24xx_serial_start_tx_dma) from [<c0804338>] (s3c24xx_serial_tx_chars+0x198/0x33c) Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com> Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions") CC: stable@vger.kernel.org # v4.0+ Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-05-17tty: pty: Fix ldisc flush after userspace become aware of the data alreadyWang YanQing
[ Upstream commit 77dae6134440420bac334581a3ccee94cee1c054 ] While using emacs, cat or others' commands in konsole with recent kernels, I have met many times that CTRL-C freeze konsole. After konsole freeze I can't type anything, then I have to open a new one, it is very annoying. See bug report: https://bugs.kde.org/show_bug.cgi?id=175283 The platform in that bug report is Solaris, but now the pty in linux has the same problem or the same behavior as Solaris :) It has high possibility to trigger the problem follow steps below: Note: In my test, BigFile is a text file whose size is bigger than 1G 1:open konsole 1:cat BigFile 2:CTRL-C After some digging, I find out the reason is that commit 1d1d14da12e7 ("pty: Fix buffer flush deadlock") changes the behavior of pty_flush_buffer. Thread A Thread B -------- -------- 1:n_tty_poll return POLLIN 2:CTRL-C trigger pty_flush_buffer tty_buffer_flush n_tty_flush_buffer 3:attempt to check count of chars: ioctl(fd, TIOCINQ, &available) available is equal to 0 4:read(fd, buffer, avaiable) return 0 5:konsole close fd Yes, I know we could use the same patch included in the BUG report as a workaround for linux platform too. But I think the data in ldisc is belong to application of another side, we shouldn't clear it when we want to flush write buffer of this side in pty_flush_buffer. So I think it is better to disable ldisc flush in pty_flush_buffer, because its new hehavior bring no benefit except that it mess up the behavior between POLLIN, and TIOCINQ or FIONREAD. Also I find no flush_buffer function in others' tty driver has the same behavior as current pty_flush_buffer. Fixes: 1d1d14da12e7 ("pty: Fix buffer flush deadlock") CC: stable@vger.kernel.org # v4.0+ Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-05-17serial: samsung: Continue to work if DMA request failsKrzysztof Kozlowski
[ Upstream commit f98c7bce570bdbe344b74ff5daa7dfeef3f22929 ] If DMA is not available (even when configured in DeviceTree), the driver will fail the startup procedure thus making serial console not available. For example this causes boot failure on QEMU ARMv7 (Exynos4210, SMDKC210): [    1.302575] OF: amba_device_add() failed (-19) for /amba/pdma@12680000 ... [   11.435732] samsung-uart 13800000.serial: DMA request failed [   72.963893] samsung-uart 13800000.serial: DMA request failed [   73.143361] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000 DMA is not necessary for serial to work, so continue with UART startup after emitting a warning. Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions") Cc: <stable@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-05-17serial: 8250_pci: Add MKS Tenta SCOM-0800 and SCOM-0801 cardsIan Abbott
[ Upstream commit 1c9c858e2ff8ae8024a3d75d2ed080063af43754 ] The MKS Instruments SCOM-0800 and SCOM-0801 cards (originally by Tenta Technologies) are 3U CompactPCI serial cards with 4 and 8 serial ports, respectively. The first 4 ports are implemented by an OX16PCI954 chip, and the second 4 ports are implemented by an OX16C954 chip on a local bus, bridged by the second PCI function of the OX16PCI954. The ports are jumper-selectable as RS-232 and RS-422/485, and the UARTs use a non-standard oscillator frequency of 20 MHz (base_baud = 1250000). Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
2017-05-15tty: serial: msm: Fix module autoloadJavier Martinez Canillas
[ Upstream commit abe81f3b8ed2996e1712d26d38ff6b73f582c616 ] If the driver is built as a module, autoload won't work because the module alias information is not filled. So user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Before this patch: $ modinfo drivers/tty/serial/msm_serial.ko | grep alias $ After this patch: $ modinfo drivers/tty/serial/msm_serial.ko | grep alias alias: of:N*T*Cqcom,msm-uartdmC* alias: of:N*T*Cqcom,msm-uartdm alias: of:N*T*Cqcom,msm-uartC* alias: of:N*T*Cqcom,msm-uart Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>