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2018-08-22serial: 8250_dw: always set baud rate in dw8250_set_termiosChen Hu
commit dfcab6ba573445c703235ab6c83758eec12d7f28 upstream. dw8250_set_termios() doesn't set baud rate if the arg "old ktermios" is NULL. This happens during resume. Call Trace: ... [ 54.928108] dw8250_set_termios+0x162/0x170 [ 54.928114] serial8250_set_termios+0x17/0x20 [ 54.928117] uart_change_speed+0x64/0x160 [ 54.928119] uart_resume_port ... So the baud rate is not restored after S3 and breaks the apps who use UART, for example, console and bluetooth etc. We address this issue by setting the baud rate irrespective of arg "old", just like the drivers for other 8250 IPs. This is tested with Intel Broxton platform. Signed-off-by: Chen Hu <hu1.chen@intel.com> Fixes: 4e26b134bd17 ("serial: 8250_dw: clock rate handling for all ACPI platforms") Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06tty: Fix data race in tty_insert_flip_string_fixed_flagDaeRyong Jeong
[ Upstream commit b6da31b2c07c46f2dcad1d86caa835227a16d9ff ] Unlike normal serials, in pty layer, there is no guarantee that multiple threads don't insert input characters at the same time. If it is happened, tty_insert_flip_string_fixed_flag can be executed concurrently. This can lead slab out-of-bounds write in tty_insert_flip_string_fixed_flag. Call sequences are as follows. CPU0 CPU1 n_tty_ioctl_helper n_tty_ioctl_helper __start_tty tty_send_xchar tty_wakeup pty_write n_hdlc_tty_wakeup tty_insert_flip_string n_hdlc_send_frames tty_insert_flip_string_fixed_flag pty_write tty_insert_flip_string tty_insert_flip_string_fixed_flag To fix the race, acquire port->lock in pty_write() before it inserts input characters to tty buffer. It prevents multiple threads from inserting input characters concurrently. The crash log is as follows: BUG: KASAN: slab-out-of-bounds in tty_insert_flip_string_fixed_flag+0xb5/ 0x130 drivers/tty/tty_buffer.c:316 at addr ffff880114fcc121 Write of size 1792 by task syz-executor0/30017 CPU: 1 PID: 30017 Comm: syz-executor0 Not tainted 4.8.0 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014 0000000000000000 ffff88011638f888 ffffffff81694cc3 ffff88007d802140 ffff880114fcb300 ffff880114fcc300 ffff880114fcb300 ffff88011638f8b0 ffffffff8130075c ffff88011638f940 ffff88007d802140 ffff880194fcc121 Call Trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0xb3/0x110 lib/dump_stack.c:51 kasan_object_err+0x1c/0x70 mm/kasan/report.c:156 print_address_description mm/kasan/report.c:194 [inline] kasan_report_error+0x1f7/0x4e0 mm/kasan/report.c:283 kasan_report+0x36/0x40 mm/kasan/report.c:303 check_memory_region_inline mm/kasan/kasan.c:292 [inline] check_memory_region+0x13e/0x1a0 mm/kasan/kasan.c:299 memcpy+0x37/0x50 mm/kasan/kasan.c:335 tty_insert_flip_string_fixed_flag+0xb5/0x130 drivers/tty/tty_buffer.c:316 tty_insert_flip_string include/linux/tty_flip.h:35 [inline] pty_write+0x7f/0xc0 drivers/tty/pty.c:115 n_hdlc_send_frames+0x1d4/0x3b0 drivers/tty/n_hdlc.c:419 n_hdlc_tty_wakeup+0x73/0xa0 drivers/tty/n_hdlc.c:496 tty_wakeup+0x92/0xb0 drivers/tty/tty_io.c:601 __start_tty.part.26+0x66/0x70 drivers/tty/tty_io.c:1018 __start_tty+0x34/0x40 drivers/tty/tty_io.c:1013 n_tty_ioctl_helper+0x146/0x1e0 drivers/tty/tty_ioctl.c:1138 n_hdlc_tty_ioctl+0xb3/0x2b0 drivers/tty/n_hdlc.c:794 tty_ioctl+0xa85/0x16d0 drivers/tty/tty_io.c:2992 vfs_ioctl fs/ioctl.c:43 [inline] do_vfs_ioctl+0x13e/0xba0 fs/ioctl.c:679 SYSC_ioctl fs/ioctl.c:694 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 entry_SYSCALL_64_fastpath+0x1f/0xbd Signed-off-by: DaeRyong Jeong <threeearcat@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-06hvc_opal: don't set tb_ticks_per_usec in udbg_init_opal_common()Stewart Smith
[ Upstream commit 447808bf500a7cc92173266a59f8a494e132b122 ] time_init() will set up tb_ticks_per_usec based on reality. time_init() is called *after* udbg_init_opal_common() during boot. from arch/powerpc/kernel/time.c: unsigned long tb_ticks_per_usec = 100; /* sane default */ Currently, all powernv systems have a timebase frequency of 512mhz (512000000/1000000 == 0x200) - although there's nothing written down anywhere that I can find saying that we couldn't make that different based on the requirements in the ISA. So, we've been (accidentally) thwacking the (currently) correct (for powernv at least) value for tb_ticks_per_usec earlier than we otherwise would have. The "sane default" seems to be adequate for our purposes between udbg_init_opal_common() and time_init() being called, and if it isn't, then we should probably be setting it somewhere that isn't hvc_opal.c! Signed-off-by: Stewart Smith <stewart@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11n_tty: Access echo_* variables carefully.Tetsuo Handa
commit ebec3f8f5271139df618ebdf8427e24ba102ba94 upstream. syzbot is reporting stalls at __process_echoes() [1]. This is because since ldata->echo_commit < ldata->echo_tail becomes true for some reason, the discard loop is serving as almost infinite loop. This patch tries to avoid falling into ldata->echo_commit < ldata->echo_tail situation by making access to echo_* variables more carefully. Since reset_buffer_flags() is called without output_lock held, it should not touch echo_* variables. And omit a call to reset_buffer_flags() from n_tty_open() by using vzalloc(). Since add_echo_byte() is called without output_lock held, it needs memory barrier between storing into echo_buf[] and incrementing echo_head counter. echo_buf() needs corresponding memory barrier before reading echo_buf[]. Lack of handling the possibility of not-yet-stored multi-byte operation might be the reason of falling into ldata->echo_commit < ldata->echo_tail situation, for if I do WARN_ON(ldata->echo_commit == tail + 1) prior to echo_buf(ldata, tail + 1), the WARN_ON() fires. Also, explicitly masking with buffer for the former "while" loop, and use ldata->echo_commit > tail for the latter "while" loop. [1] https://syzkaller.appspot.com/bug?id=17f23b094cd80df750e5b0f8982c521ee6bcbf40 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+108696293d7a21ab688f@syzkaller.appspotmail.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11n_tty: Fix stall at n_tty_receive_char_special().Tetsuo Handa
commit 3d63b7e4ae0dc5e02d28ddd2fa1f945defc68d81 upstream. syzbot is reporting stalls at n_tty_receive_char_special() [1]. This is because comparison is not working as expected since ldata->read_head can change at any moment. Mitigate this by explicitly masking with buffer size when checking condition for "while" loops. [1] https://syzkaller.appspot.com/bug?id=3d7481a346958d9469bebbeb0537d5f056bdd6e8 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+18df353d7540aa6b5467@syzkaller.appspotmail.com> Fixes: bc5a5e3f45d04784 ("n_tty: Don't wrap input buffer indices at buffer size") Cc: stable <stable@vger.kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03serial: sh-sci: Use spin_{try}lock_irqsave instead of open coding versionDaniel Wagner
commit 8afb1d2c12163f77777f84616a8e9444d0050ebe upstream. Commit 40f70c03e33a ("serial: sh-sci: add locking to console write function to avoid SMP lockup") copied the strategy to avoid locking problems in conjuncture with the console from the UART8250 driver. Instead using directly spin_{try}lock_irqsave(), local_irq_save() followed by spin_{try}lock() was used. While this is correct on mainline, for -rt it is a problem. spin_{try}lock() will check if it is running in a valid context. Since the local_irq_save() has already been executed, the context has changed and spin_{try}lock() will complain. The reason why spin_{try}lock() complains is that on -rt the spin locks are turned into mutexes and therefore can sleep. Sleeping with interrupts disabled is not valid. BUG: sleeping function called from invalid context at /home/wagi/work/rt/v4.4-cip-rt/kernel/locking/rtmutex.c:995 in_atomic(): 0, irqs_disabled(): 128, pid: 778, name: irq/76-eth0 CPU: 0 PID: 778 Comm: irq/76-eth0 Not tainted 4.4.126-test-cip22-rt14-00403-gcd03665c8318 #12 Hardware name: Generic RZ/G1 (Flattened Device Tree) Backtrace: [<c00140a0>] (dump_backtrace) from [<c001424c>] (show_stack+0x18/0x1c) r7:c06b01f0 r6:60010193 r5:00000000 r4:c06b01f0 [<c0014234>] (show_stack) from [<c01d3c94>] (dump_stack+0x78/0x94) [<c01d3c1c>] (dump_stack) from [<c004c134>] (___might_sleep+0x134/0x194) r7:60010113 r6:c06d3559 r5:00000000 r4:ffffe000 [<c004c000>] (___might_sleep) from [<c04ded60>] (rt_spin_lock+0x20/0x74) r5:c06f4d60 r4:c06f4d60 [<c04ded40>] (rt_spin_lock) from [<c02577e4>] (serial_console_write+0x100/0x118) r5:c06f4d60 r4:c06f4d60 [<c02576e4>] (serial_console_write) from [<c0061060>] (call_console_drivers.constprop.15+0x10c/0x124) r10:c06d2894 r9:c04e18b0 r8:00000028 r7:00000000 r6:c06d3559 r5:c06d2798 r4:c06b9914 r3:c02576e4 [<c0060f54>] (call_console_drivers.constprop.15) from [<c0062984>] (console_unlock+0x32c/0x430) r10:c06d30d8 r9:00000028 r8:c06dd518 r7:00000005 r6:00000000 r5:c06d2798 r4:c06d2798 r3:00000028 [<c0062658>] (console_unlock) from [<c0062e1c>] (vprintk_emit+0x394/0x4f0) r10:c06d2798 r9:c06d30ee r8:00000006 r7:00000005 r6:c06a78fc r5:00000027 r4:00000003 [<c0062a88>] (vprintk_emit) from [<c0062fa0>] (vprintk+0x28/0x30) r10:c060bd46 r9:00001000 r8:c06b9a90 r7:c06b9a90 r6:c06b994c r5:c06b9a3c r4:c0062fa8 [<c0062f78>] (vprintk) from [<c0062fb8>] (vprintk_default+0x10/0x14) [<c0062fa8>] (vprintk_default) from [<c009cd30>] (printk+0x78/0x84) [<c009ccbc>] (printk) from [<c025afdc>] (credit_entropy_bits+0x17c/0x2cc) r3:00000001 r2:decade60 r1:c061a5ee r0:c061a523 r4:00000006 [<c025ae60>] (credit_entropy_bits) from [<c025bf74>] (add_interrupt_randomness+0x160/0x178) r10:466e7196 r9:1f536000 r8:fffeef74 r7:00000000 r6:c06b9a60 r5:c06b9a3c r4:dfbcf680 [<c025be14>] (add_interrupt_randomness) from [<c006536c>] (irq_thread+0x1e8/0x248) r10:c006537c r9:c06cdf21 r8:c0064fcc r7:df791c24 r6:df791c00 r5:ffffe000 r4:df525180 [<c0065184>] (irq_thread) from [<c003fba4>] (kthread+0x108/0x11c) r10:00000000 r9:00000000 r8:c0065184 r7:df791c00 r6:00000000 r5:df791d00 r4:decac000 [<c003fa9c>] (kthread) from [<c00101b8>] (ret_from_fork+0x14/0x3c) r8:00000000 r7:00000000 r6:00000000 r5:c003fa9c r4:df791d00 Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> [dw: Backported to 4.4.] Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-16serial: samsung: fix maxburst parameter for DMA transactionsMarek Szyprowski
commit aa2f80e752c75e593b3820f42c416ed9458fa73e upstream. The best granularity of residue that DMA engine can report is in the BURST units, so the serial driver must use MAXBURST = 1 and DMA_SLAVE_BUSWIDTH_1_BYTE if it relies on exact number of bytes transferred by DMA engine. Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30serial: arc_uart: Fix out-of-bounds access through DT aliasGeert Uytterhoeven
[ Upstream commit f9f5786987e81d166c60833edcb7d1836aa16944 ] The arc_uart_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_ARC_NR_PORTS), so this can even be triggered using a legitimate DTB. Fixes: ea28fd56fcde69af ("serial/arc-uart: switch to devicetree based probing") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30serial: fsl_lpuart: Fix out-of-bounds access through DT aliasGeert Uytterhoeven
[ Upstream commit ffab87fdecc655cc676f8be8dd1a2c5e22bd6d47 ] The lpuart_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: c9e2e946fb0ba5d2 ("tty: serial: add Freescale lpuart driver support") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30serial: imx: Fix out-of-bounds access through serial port indexGeert Uytterhoeven
[ Upstream commit 5673444821406dda5fc25e4b52aca419f8065a19 ] The imx_ports[] array is indexed using a value derived from the "serialN" alias in DT, or from platform data, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: ff05967a07225ab6 ("serial/imx: add of_alias_get_id() reference back") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30serial: mxs-auart: Fix out-of-bounds access through serial port indexGeert Uytterhoeven
[ Upstream commit dd345a31bfdec350d2593e6de5964e55c7f19c76 ] The auart_port[] array is indexed using a value derived from the "serialN" alias in DT, or from platform data, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: 1ea6607d4cdc9179 ("serial: mxs-auart: Allow device tree probing") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30serial: samsung: Fix out-of-bounds access through serial port indexGeert Uytterhoeven
[ Upstream commit 49ee23b71877831ac087d6083f6f397dc19c9664 ] The s3c24xx_serial_ports[] array is indexed using a value derived from the "serialN" alias in DT, or from an incrementing probe index, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_SAMSUNG_UARTS), so this can even be triggered using a legitimate DTB or legitimate board code. Fixes: 13a9f6c64fdc55eb ("serial: samsung: Consider DT alias when probing ports") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30serial: xuartps: Fix out-of-bounds access through DT aliasGeert Uytterhoeven
[ Upstream commit e7d75e18d0fc3f7193b65282b651f980c778d935 ] The cdns_uart_port[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Fixes: 928e9263492069ee ("tty: xuartps: Initialize ports according to aliases") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-02serial: mctrl_gpio: Add missing module licenseRomain Izard
commit 82a3f87f6e80e0bf7978152021eb8938976721cb upstream. As the mctrl_gpio driver can be built as a module, it needs to have its license specified with MODULE_LICENSE. Otherwise, it cannot access required symbols exported through EXPORT_SYMBOL_GPL. Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Wagner <wagi@monom.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-02serial: mctrl_gpio: export mctrl_gpio_disable_ms and mctrl_gpio_initUwe Kleine-König
commit 4f71a2e0a282611e55bacb60b564eaef5d16c27b upstream. To be able to make use of the mctrl-gpio helper from a module these functions must be exported. This was forgotten in the commit introducing support interrupt handling for these functions (while it was done for mctrl_gpio_enable_ms, *sigh*). Fixes: ce59e48fdbad ("serial: mctrl_gpio: implement interrupt handling") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Daniel Wagner <wagi@monom.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-02tty: Use __GFP_NOFAIL for tty_ldisc_get()Tetsuo Handa
commit bcdd0ca8cb8730573afebcaae4138f8f4c8eaa20 upstream. 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-02tty: n_gsm: Fix DLCI handling for ADM mode if debug & 2 is not setTony Lindgren
commit b2d89ad9c9682e795ed6eeb9ed455789ad6cedf1 upstream. 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>
2018-05-02tty: n_gsm: Fix long delays with control frame timeouts in ADM modeTony Lindgren
commit e9ec22547986dd32c5c70da78107ce35dbff1344 upstream. 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>
2018-05-02tty: Don't call panic() at tty_ldisc_init()Tetsuo Handa
commit 903f9db10f18f735e62ba447147b6c434b6af003 upstream. 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>
2018-04-24tty: make n_tty_read() always abort if hangup is in progressTejun Heo
commit 28b0f8a6962a24ed21737578f3b1b07424635c9e upstream. 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>
2018-04-13tty: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13Fix 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13serial: sh-sci: Fix race condition causing garbage during shutdownGeert Uytterhoeven
[ Upstream commit 1cf4a7efdc71cab84c42cfea7200608711ea954f ] If DMA is enabled and used, a burst of old data may be seen on the serial console during "poweroff" or "reboot". uart_flush_buffer() clears the circular buffer, but sci_port.tx_dma_len is not reset. This leads to a circular buffer overflow, dumping (UART_XMIT_SIZE - sci_port.tx_dma_len) bytes. To fix this, add a .flush_buffer() callback that resets sci_port.tx_dma_len. Inspired by commit 31ca2c63fdc0aee7 ("tty/serial: atmel: fix race condition (TX+DMA)"). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-13serial: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-08vt: change SGR 21 to follow the standardsMike Frysinger
commit 65d9982d7e523a1a8e7c9af012da0d166f72fc56 upstream. 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28tty: vt: fix up tabstops properlyLinus Torvalds
commit f1869a890cdedb92a3fab969db5d0fd982850273 upstream. 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-24pty: cancel pty slave port buf's work in tty_releaseSahara
[ Upstream commit 2b022ab7542df60021ab57854b3faaaf42552eaf ] In case that CONFIG_SLUB_DEBUG is on and pty is used, races between release_one_tty and flush_to_ldisc work threads may happen and lead to use-after-free condition on tty->link->port. Because SLUB_DEBUG is turned on, freed tty->link->port is filled with POISON_FREE value. So far without SLUB_DEBUG, port was filled with zero and flush_to_ldisc could return without a problem by checking if tty is NULL. CPU 0 CPU 1 ----- ----- release_tty pty_write cancel_work_sync(tty) to = tty->link tty_kref_put(tty->link) tty_schedule_flip(to->port) << workqueue >> ... release_one_tty ... pty_cleanup ... kfree(tty->link->port) << workqueue >> flush_to_ldisc tty = READ_ONCE(port->itty) tty is 0x6b6b6b6b6b6b6b6b !!PANIC!! access tty->ldisc Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b6b93 pgd = ffffffc0eb1c3000 [6b6b6b6b6b6b6b93] *pgd=0000000000000000, *pud=0000000000000000 ------------[ cut here ]------------ Kernel BUG at ffffff800851154c [verbose debug info unavailable] Internal error: Oops - BUG: 96000004 [#1] PREEMPT SMP CPU: 3 PID: 265 Comm: kworker/u8:9 Tainted: G W 3.18.31-g0a58eeb #1 Hardware name: Qualcomm Technologies, Inc. MSM 8996pro v1.1 + PMI8996 Carbide (DT) Workqueue: events_unbound flush_to_ldisc task: ffffffc0ed610ec0 ti: ffffffc0ed624000 task.ti: ffffffc0ed624000 PC is at ldsem_down_read_trylock+0x0/0x4c LR is at tty_ldisc_ref+0x24/0x4c pc : [<ffffff800851154c>] lr : [<ffffff800850f6c0>] pstate: 80400145 sp : ffffffc0ed627cd0 x29: ffffffc0ed627cd0 x28: 0000000000000000 x27: ffffff8009e05000 x26: ffffffc0d382cfa0 x25: 0000000000000000 x24: ffffff800a012f08 x23: 0000000000000000 x22: ffffffc0703fbc88 x21: 6b6b6b6b6b6b6b6b x20: 6b6b6b6b6b6b6b93 x19: 0000000000000000 x18: 0000000000000001 x17: 00e80000f80d6f53 x16: 0000000000000001 x15: 0000007f7d826fff x14: 00000000000000a0 x13: 0000000000000000 x12: 0000000000000109 x11: 0000000000000000 x10: 0000000000000000 x9 : ffffffc0ed624000 x8 : ffffffc0ed611580 x7 : 0000000000000000 x6 : ffffff800a42e000 x5 : 00000000000003fc x4 : 0000000003bd1201 x3 : 0000000000000001 x2 : 0000000000000001 x1 : ffffff800851004c x0 : 6b6b6b6b6b6b6b93 Signed-off-by: Sahara <keun-o.park@darkmatter.ae> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-18serial: 8250_pci: Add Brainboxes UC-260 4 port serial deviceNikola Ciprich
commit 9f2068f35729948bde84d87a40d135015911345d upstream. 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>
2018-03-18tty/serial: atmel: add new version check for usartJonas Danielsson
commit fd63a8903a2c40425a9811c3371dd4d0f42c0ad3 upstream. 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>
2018-03-18serial: sh-sci: prevent lockup on full TTY buffersUlrich Hecht
commit 7842055bfce4bf0170d0f61df8b2add8399697be upstream. 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>
2018-02-25serial: 8250_mid: fix broken DMA dependencyHeikki Krogerus
commit 0ff4230584320b2153752ba54e2e8edbd6addf2c upstream. In order to enable HSU DMA PCI driver, the HSU DMA Engine must be enabled. This add a check for that. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25tty: cyclades: cyz_interrupt is only used for PCIArnd Bergmann
commit 05ead49691d245f67bdd1b30cab5d9af522ac884 upstream. 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>
2018-02-25tty: hvc_xen: hide xen_console_remove when unusedArnd Bergmann
commit e36ae3439936e13c33f5841c7c2c1a9875acbb6d upstream. 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-03serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTSFabio Estevam
commit 38b1f0fb42f772b8c9aac53593883a18ff5eb9d7 upstream. The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS lines, so only allow such wakeup method when the system actually has RTS/CTS support. Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD") Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> Reviewed-by: Martin Kaiser <martin@kaiser.cx> Acked-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17sysrq: Fix warning in sysrq generated crash.Ani Sinha
commit 984cf355aeaa8f2eda3861b50d0e8d3e3f77e83b upstream. 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: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD)Linus Torvalds
commit 966031f340185eddd05affcf72b740549f056348 upstream. 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>
2017-12-09sysrq : 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@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-09serial: 8250: Preserve DLD[7:4] for PORT_XR17V35XAaron Sierra
[ Upstream commit 0ab84da2e076948c49d36197ee7d254125c53eab ] The upper four bits of the XR17V35x fractional divisor register (DLD) control general chip function (RS-485 direction pin polarity, multidrop mode, XON/XOFF parity check, and fast IR mode). Don't allow these bits to be clobbered when setting the baudrate. Signed-off-by: Aaron Sierra <asierra@xes-inc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-09serial: 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@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-09serial: 8250_pci: Add Amazon PCI serial device IDMatt Wilson
commit 3bfd1300abfe3adb18e84a89d97a0e82a22124bb upstream. 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 Signed-off-by: Matt Wilson <msw@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-24serial: omap: Fix EFR write on RTS deassertionLukas Wunner
commit 2a71de2f7366fb1aec632116d0549ec56d6a3940 upstream. 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> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15serial: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21Revert "tty: goldfish: Fix a parameter of a call to free_irq"Greg Kroah-Hartman
This reverts commit 01b3db29ba1edd79b9c3e7cd294739b70257d278 which is commit 1a5c2d1de7d35f5eb9793266237903348989502b upstream. Ben writes: This fixes a bug introduced in 4.6 by commit 465893e18878 "tty: goldfish: support platform_device with id -1". For earlier kernel versions, it *introduces* a bug. So let's drop it. Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
2017-10-21sparc64: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-08tty: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27tty: fix __tty_insert_flip_char regressionArnd Bergmann
commit 8a5a90a2a477b86a3dc2eaa5a706db9bfdd647ca upstream. 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>
2017-09-27tty: improve tty_insert_flip_char() slow pathArnd Bergmann
commit 065ea0a7afd64d6cf3464bdd1d8cd227527e2045 upstream. 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>
2017-09-27tty: improve tty_insert_flip_char() fast pathArnd Bergmann
commit 979990c6284814617d8f2179d197f72ff62b5d85 upstream. 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. Fixes: c420f167db8c ("kasan: enable stack instrumentation") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21vt: fix unchecked __put_user() in tioclinux ioctlsAdam Borowski
commit 6987dc8a70976561d22450b5858fc9767788cc1c upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-26serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'Christophe JAILLET
commit be40597a1bc173bf9dadccdf5388b956f620ae8f upstream. 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>