aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/tty
AgeCommit message (Collapse)Author
2019-09-16sunhv: Fix device naming inconsistency between sunhv_console and sunhv_regJohn Paul Adrian Glaubitz
commit 07a6d63eb1b54b5fb38092780fe618dfe1d96e23 upstream. In d5a2aa24, the name in struct console sunhv_console was changed from "ttyS" to "ttyHV" while the name in struct uart_ops sunhv_pops remained unchanged. This results in the hypervisor console device to be listed as "ttyHV0" under /proc/consoles while the device node is still named "ttyS0": root@osaka:~# cat /proc/consoles ttyHV0 -W- (EC p ) 4:64 tty0 -WU (E ) 4:1 root@osaka:~# readlink /sys/dev/char/4:64 ../../devices/root/f02836f0/f0285690/tty/ttyS0 root@osaka:~# This means that any userland code which tries to determine the name of the device file of the hypervisor console device can not rely on the information provided by /proc/consoles. In particular, booting current versions of debian- installer inside a SPARC LDOM will fail with the installer unable to determine the console device. After renaming the device in struct uart_ops sunhv_pops to "ttyHV" as well, the inconsistency is fixed and it is possible again to determine the name of the device file of the hypervisor console device by reading the contents of /proc/console: root@osaka:~# cat /proc/consoles ttyHV0 -W- (EC p ) 4:64 tty0 -WU (E ) 4:1 root@osaka:~# readlink /sys/dev/char/4:64 ../../devices/root/f02836f0/f0285690/tty/ttyHV0 root@osaka:~# With this change, debian-installer works correctly when installing inside a SPARC LDOM. Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-16dmaengine: idma64: Use actual device for DMA transfersAndy Shevchenko
commit 5ba846b1ee0792f5a596b9b0b86d6e8cdebfab06 upstream. Intel IOMMU, when enabled, tries to find the domain of the device, assuming it's a PCI one, during DMA operations, such as mapping or unmapping. Since we are splitting the actual PCI device to couple of children via MFD framework (see drivers/mfd/intel-lpss.c for details), the DMA device appears to be a platform one, and thus not an actual one that performs DMA. In a such situation IOMMU can't find or allocate a proper domain for its operations. As a result, all DMA operations are failed. In order to fix this, supply parent of the platform device to the DMA engine framework and fix filter functions accordingly. We may rely on the fact that parent is a real PCI device, because no other configuration is present in the wild. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [for tty parts] Signed-off-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12TTY: serial_core, add ->installJiri Slaby
commit 4cdd17ba1dff20ffc99fdbd2e6f0201fc7fe67df upstream. We need to compute the uart state only on the first open. This is usually what is done in the ->install hook. serial_core used to do this in ->open on every open. So move it to ->install. As a side effect, it ensures the state is set properly in the window after tty_init_dev is called, but before uart_open. This fixes a bunch of races between tty_open and flush_to_ldisc we were dealing with recently. One of such bugs was attempted to fix in commit fedb5760648a (serial: fix race between flush_to_ldisc and tty_open), but it only took care of a couple of functions (uart_start and uart_unthrottle). I was able to reproduce the crash on a SLE system, but in uart_write_room which is also called from flush_to_ldisc via process_echoes. I was *unable* to reproduce the bug locally. It is due to having this patch in my queue since 2012! general protection fault: 0000 [#1] SMP KASAN PTI CPU: 1 PID: 5 Comm: kworker/u4:0 Tainted: G L 4.12.14-396-default #1 SLE15-SP1 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014 Workqueue: events_unbound flush_to_ldisc task: ffff8800427d8040 task.stack: ffff8800427f0000 RIP: 0010:uart_write_room+0xc4/0x590 RSP: 0018:ffff8800427f7088 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 000000000000002f RSI: 00000000000000ee RDI: ffff88003888bd90 RBP: ffffffffb9545850 R08: 0000000000000001 R09: 0000000000000400 R10: ffff8800427d825c R11: 000000000000006e R12: 1ffff100084fee12 R13: ffffc900004c5000 R14: ffff88003888bb28 R15: 0000000000000178 FS: 0000000000000000(0000) GS:ffff880043300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561da0794148 CR3: 000000000ebf4000 CR4: 00000000000006e0 Call Trace: tty_write_room+0x6d/0xc0 __process_echoes+0x55/0x870 n_tty_receive_buf_common+0x105e/0x26d0 tty_ldisc_receive_buf+0xb7/0x1c0 tty_port_default_receive_buf+0x107/0x180 flush_to_ldisc+0x35d/0x5c0 ... 0 in rbx means tty->driver_data is NULL in uart_write_room. 0x178 is tried to be dereferenced (0x178 >> 3 is 0x2f in rdx) at uart_write_room+0xc4. 0x178 is exactly (struct uart_state *)NULL->refcount used in uart_port_lock from uart_write_room. So revert the upstream commit here as my local patch should fix the whole family. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Li RongQing <lirongqing@baidu.com> Cc: Wang Li <wangli39@baidu.com> Cc: Zhang Yu <zhangyu31@baidu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12serial: sh-sci: disable DMA for uart_consoleGeorge G. Davis
commit 099506cbbc79c0bd52b19cb6b930f256dabc3950 upstream. As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for console UART"), UART console lines use low-level PIO only access functions which will conflict with use of the line when DMA is enabled, e.g. when the console line is also used for systemd messages. So disable DMA support for UART console lines. Reported-by: Michael Rodin <mrodin@de.adit-jv.com> Link: https://patchwork.kernel.org/patch/10929511/ Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org Signed-off-by: George G. Davis <george_davis@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12vt/fbcon: deinitialize resources in visual_init() after failed memory allocationGrzegorz Halat
commit a1ad1cc9704f64c169261a76e1aee1cf1ae51832 upstream. After memory allocation failure vc_allocate() doesn't clean up data which has been initialized in visual_init(). In case of fbcon this leads to divide-by-0 in fbcon_init() on next open of the same tty. memory allocation in vc_allocate() may fail here: 1097: vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_KERNEL); on next open() fbcon_init() skips vc_font.data initialization: 1088: if (!p->fontdata) { division by zero in fbcon_init() happens here: 1149: new_cols /= vc->vc_font.width; Additional check is needed in fbcon_deinit() to prevent usage of uninitialized vc_screenbuf: 1251: if (vc->vc_hi_font_mask && vc->vc_screenbuf) 1252: set_vc_hi_font(vc, false); Crash: #6 [ffffc90001eafa60] divide_error at ffffffff81a00be4 [exception RIP: fbcon_init+463] RIP: ffffffff814b860f RSP: ffffc90001eafb18 RFLAGS: 00010246 ... #7 [ffffc90001eafb60] visual_init at ffffffff8154c36e #8 [ffffc90001eafb80] vc_allocate at ffffffff8154f53c #9 [ffffc90001eafbc8] con_install at ffffffff8154f624 ... Signed-off-by: Grzegorz Halat <ghalat@redhat.com> Reviewed-by: Oleksandr Natalenko <oleksandr@redhat.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12tty: max310x: Fix external crystal register setupJoe Burmeister
commit 5d24f455c182d5116dd5db8e1dc501115ecc9c2c upstream. The datasheet states: Bit 4: ClockEnSet the ClockEn bit high to enable an external clocking (crystal or clock generator at XIN). Set the ClockEn bit to 0 to disable clocking Bit 1: CrystalEnSet the CrystalEn bit high to enable the crystal oscillator. When using an external clock source at XIN, CrystalEn must be set low. The bit 4, MAX310X_CLKSRC_EXTCLK_BIT, should be set and was not. This was required to make the MAX3107 with an external crystal on our board able to send or receive data. Signed-off-by: Joe Burmeister <joe.burmeister@devtank.co.uk> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12tty: serial: msm_serial: Fix XON/XOFFJorge Ramirez-Ortiz
commit 61c0e37950b88bad590056286c1d766b1f167f4e upstream. When the tty layer requests the uart to throttle, the current code executing in msm_serial will trigger "Bad mode in Error Handler" and generate an invalid stack frame in pstore before rebooting (that is if pstore is indeed configured: otherwise the user shall just notice a reboot with no further information dumped to the console). This patch replaces the PIO byte accessor with the word accessor already used in PIO mode. Fixes: 68252424a7c7 ("tty: serial: msm: Support big-endian CPUs") Cc: stable@vger.kernel.org Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-17tty: ipwireless: fix missing checks for ioremapKangjie Lu
commit 1bbb1c318cd8a3a39e8c3e2e83d5e90542d6c3e3 upstream. ipw->attr_memory and ipw->common_memory are assigned with the return value of ioremap. ioremap may fail, but no checks are enforced. The fix inserts the checks to avoid potential NULL pointer dereferences. Signed-off-by: Kangjie Lu <kjlu@umn.edu> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30tty: Don't force RISCV SBI console as preferred consoleAnup Patel
commit f91253a3d005796404ae0e578b3394459b5f9b71 upstream. The Linux kernel will auto-disables all boot consoles whenever it gets a preferred real console. Currently on RISC-V systems, if we have a real console which is not RISCV SBI console then boot consoles (such as earlycon=sbi) are not auto-disabled when a real console (ttyS0 or ttySIF0) is available. This results in duplicate prints at boot-time after kernel starts using real console (i.e. ttyS0 or ttySIF0) if "earlycon=" kernel parameter was passed by bootloader. The reason for above issue is that RISCV SBI console always adds itself as preferred console which is causing other real consoles to be not used as preferred console. Ideally "console=" kernel parameter passed by bootloaders should be the one selecting a preferred real console. This patch fixes above issue by not forcing RISCV SBI console as preferred console. Fixes: afa6b1ccfad5 ("tty: New RISC-V SBI console driver") Cc: stable@vger.kernel.org Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30tty/vt: fix write/write race in ioctl(KDSKBSENT) handlerSergei Trofimovich
commit 46ca3f735f345c9d87383dd3a09fa5d43870770e upstream. The bug manifests as an attempt to access deallocated memory: BUG: unable to handle kernel paging request at ffff9c8735448000 #PF error: [PROT] [WRITE] PGD 288a05067 P4D 288a05067 PUD 288a07067 PMD 7f60c2063 PTE 80000007f5448161 Oops: 0003 [#1] PREEMPT SMP CPU: 6 PID: 388 Comm: loadkeys Tainted: G C 5.0.0-rc6-00153-g5ded5871030e #91 Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M-D3H, BIOS F12 11/14/2013 RIP: 0010:__memmove+0x81/0x1a0 Code: 4c 89 4f 10 4c 89 47 18 48 8d 7f 20 73 d4 48 83 c2 20 e9 a2 00 00 00 66 90 48 89 d1 4c 8b 5c 16 f8 4c 8d 54 17 f8 48 c1 e9 03 <f3> 48 a5 4d 89 1a e9 0c 01 00 00 0f 1f 40 00 48 89 d1 4c 8b 1e 49 RSP: 0018:ffffa1b9002d7d08 EFLAGS: 00010203 RAX: ffff9c873541af43 RBX: ffff9c873541af43 RCX: 00000c6f105cd6bf RDX: 0000637882e986b6 RSI: ffff9c8735447ffb RDI: ffff9c8735447ffb RBP: ffff9c8739cd3800 R08: ffff9c873b802f00 R09: 00000000fffff73b R10: ffffffffb82b35f1 R11: 00505b1b004d5b1b R12: 0000000000000000 R13: ffff9c873541af3d R14: 000000000000000b R15: 000000000000000c FS: 00007f450c390580(0000) GS:ffff9c873f180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff9c8735448000 CR3: 00000007e213c002 CR4: 00000000000606e0 Call Trace: vt_do_kdgkb_ioctl+0x34d/0x440 vt_ioctl+0xba3/0x1190 ? __bpf_prog_run32+0x39/0x60 ? mem_cgroup_commit_charge+0x7b/0x4e0 tty_ioctl+0x23f/0x920 ? preempt_count_sub+0x98/0xe0 ? __seccomp_filter+0x67/0x600 do_vfs_ioctl+0xa2/0x6a0 ? syscall_trace_enter+0x192/0x2d0 ksys_ioctl+0x3a/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x54/0xe0 entry_SYSCALL_64_after_hwframe+0x49/0xbe The bug manifests on systemd systems with multiple vtcon devices: # cat /sys/devices/virtual/vtconsole/vtcon0/name (S) dummy device # cat /sys/devices/virtual/vtconsole/vtcon1/name (M) frame buffer device There systemd runs 'loadkeys' tool in tapallel for each vtcon instance. This causes two parallel ioctl(KDSKBSENT) calls to race into adding the same entry into 'func_table' array at: drivers/tty/vt/keyboard.c:vt_do_kdgkb_ioctl() The function has no locking around writes to 'func_table'. The simplest reproducer is to have initrams with the following init on a 8-CPU machine x86_64: #!/bin/sh loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & wait The change adds lock on write path only. Reads are still racy. CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Jiri Slaby <jslaby@suse.com> Link: https://lkml.org/lkml/2019/2/17/256 Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30tty: vt.c: Fix TIOCL_BLANKSCREEN console blanking if blankinterval == 0Yifeng Li
commit 75ddbc1fb11efac87b611d48e9802f6fe2bb2163 upstream. Previously, in the userspace, it was possible to use the "setterm" command from util-linux to blank the VT console by default, using the following command. According to the man page, > The force option keeps the screen blank even if a key is pressed. It was implemented by calling TIOCL_BLANKSCREEN. case BLANKSCREEN: ioctlarg = TIOCL_BLANKSCREEN; if (ioctl(STDIN_FILENO, TIOCLINUX, &ioctlarg)) warn(_("cannot force blank")); break; However, after Linux 4.12, this command ceased to work anymore, which is unexpected. By inspecting the kernel source, it shows that the issue was triggered by the side-effect from commit a4199f5eb809 ("tty: Disable default console blanking interval"). The console blanking is implemented by function do_blank_screen() in vt.c: "blank_state" will be initialized to "blank_normal_wait" in con_init() if AND ONLY IF ("blankinterval" > 0). If "blankinterval" is 0, "blank_state" will be "blank_off" (== 0), and a call to do_blank_screen() will always abort, even if a forced blanking is required from the user by calling TIOCL_BLANKSCREEN, the console won't be blanked. This behavior is unexpected from a user's point-of-view, since it's not mentioned in any documentation. The setterm man page suggests it will always work, and the kernel comments in uapi/linux/tiocl.h says > /* keep screen blank even if a key is pressed */ > #define TIOCL_BLANKSCREEN 14 To fix it, we simply remove the "blank_state != blank_off" check, as pointed out by Nicolas Pitre, this check doesn't logically make sense and it's safe to remove. Suggested-by: Nicolas Pitre <nicolas.pitre@linaro.org> Fixes: a4199f5eb809 ("tty: Disable default console blanking interval") Signed-off-by: Yifeng Li <tomli@tomli.me> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-23serial: ar933x_uart: Fix build failure with disabled consolePetr Štetiar
commit 72ff51d8dd262d1fef25baedc2ac35116435be47 upstream. Andrey has reported on OpenWrt's bug tracking system[1], that he currently can't use ar93xx_uart as pure serial UART without console (CONFIG_SERIAL_8250_CONSOLE and CONFIG_SERIAL_AR933X_CONSOLE undefined), because compilation ends with following error: ar933x_uart.c: In function 'ar933x_uart_console_write': ar933x_uart.c:550:14: error: 'struct uart_port' has no member named 'sysrq' So this patch moves all the code related to console handling behind series of CONFIG_SERIAL_AR933X_CONSOLE ifdefs. 1. https://bugs.openwrt.org/index.php?do=details&task_id=2152 Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Andrey Batyiev <batyiev@gmail.com> Reported-by: Andrey Batyiev <batyiev@gmail.com> Tested-by: Andrey Batyiev <batyiev@gmail.com> Signed-off-by: Petr Štetiar <ynezz@true.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-23sc16is7xx: move label 'err_spi' to correct sectionGuoqing Jiang
commit e00164a0f000de893944981f41a568c981aca658 upstream. err_spi is used when SERIAL_SC16IS7XX_SPI is enabled, so make the label only available under SERIAL_SC16IS7XX_SPI option. Otherwise, the below warning appears. drivers/tty/serial/sc16is7xx.c:1523:1: warning: label ‘err_spi’ defined but not used [-Wunused-label] err_spi: ^~~~~~~ Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Fixes: ac0cdb3d9901 ("sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-23sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()Mao Wenan
commit ac0cdb3d990108df795b676cd0d0e65ac34b2273 upstream. Add the missing uart_unregister_driver() and i2c_del_driver() before return from sc16is7xx_init() in the error handling case. Signed-off-by: Mao Wenan <maowenan@huawei.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-15vt: fix cursor when clearing the screenMikulas Patocka
commit b2ecf00631362a83744e5ec249947620db5e240c upstream. The patch a6dbe4427559 ("vt: perform safe console erase in the right order") introduced a bug. The conditional do_update_region() was replaced by a call to update_region() that does contain the conditional already, but with unwanted extra side effects such as restoring the cursor drawing. In order to reproduce the bug: - use framebuffer console with the AMDGPU driver - type "links" to start the console www browser - press 'q' and space to exit links Now the cursor will be permanently visible in the center of the screen. It will stay there until something overwrites it. The bug goes away if we change update_region() back to the conditional do_update_region(). [ nico: reworded changelog ] Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Cc: stable@vger.kernel.org Fixes: a6dbe4427559 ("vt: perform safe console erase in the right order") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-15serial: sh-sci: Fix HSCIF RX sampling point calculationGeert Uytterhoeven
commit ace965696da2611af759f0284e26342b7b6cec89 upstream. There are several issues with the formula used for calculating the deviation from the intended rate: 1. While min_err and last_stop are signed, srr and baud are unsigned. Hence the signed values are promoted to unsigned, which will lead to a bogus value of deviation if min_err is negative, 2. Srr is the register field value, which is one less than the actual sampling rate factor, 3. The divisions do not use rounding. Fix this by casting unsigned variables to int, adding one to srr, and using a single DIV_ROUND_CLOSEST(). Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Cc: stable <stable@vger.kernel.org> Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-15serial: sh-sci: Fix HSCIF RX sampling point adjustmentGeert Uytterhoeven
commit 6b87784b53592a90d21576be8eff688b56d93cce upstream. The calculation of the sampling point has min() and max() exchanged. Fix this by using the clamp() helper instead. Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Dirk Behme <dirk.behme@de.bosch.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-05serial: uartps: console_setup() can't be placed to init sectionMichal Simek
commit 4bb1ce2350a598502b23088b169e16b43d4bc639 upstream. When console device is rebinded, console_setup() is called again. But marking it as __init means that function will be clear after boot is complete. If console device is binded again console_setup() is not found and error "Unable to handle kernel paging request at virtual address" is reported. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-05tty: ldisc: add sysctl to prevent autoloading of ldiscsGreg Kroah-Hartman
commit 7c0cca7c847e6e019d67b7d793efbbe3b947d004 upstream. By default, the kernel will automatically load the module of any line dicipline that is asked for. As this sometimes isn't the safest thing to do, provide a sysctl to disable this feature. By default, we set this to 'y' as that is the historical way that Linux has worked, and we do not want to break working systems. But in the future, perhaps this can default to 'n' to prevent this functionality. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-12tty: increase the default flip buffer limit to 2*640KManfred Schlaegl
commit 7ab57b76ebf632bf2231ccabe26bea33868118c6 upstream. We increase the default limit for buffer memory allocation by a factor of 10 to 640K to prevent data loss when using fast serial interfaces. For example when using RS485 without flow-control at speeds of 1Mbit/s an upwards we've run into problems such as applications being too slow to read out this buffer (on embedded devices based on imx53 or imx6). If you want to write transmitted data to a slow SD card and thus have realtime requirements, this limit can become a problem. That shouldn't be the case and 640K buffers fix such problems for us. This value is a maximum limit for allocation only. It has no effect on systems that currently run fine. When transmission is slow enough applications and hardware can keep up and increasing this limit doesn't change anything. It only _allows_ to allocate more than 2*64K in cases we currently fail to allocate memory despite having some. Signed-off-by: Manfred Schlaegl <manfred.schlaegl@ginzinger.com> Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-12serial: 8250_pxa: honor the port number from devicetreeLubomir Rintel
commit fe9ed6d2483fda55465f32924fb15bce0fac3fac upstream. Like the other OF-enabled drivers, use the port number from the firmware if the devicetree specifies an alias: aliases { ... serial2 = &uart2; /* Should be ttyS2 */ } This is how the deprecated pxa.c driver behaved, switching to 8250_pxa messes up the numbering. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-12tty/serial_core: add ISO7816 infrastructureNicolas Ferre
commit ad8c0eaa0a418ae8ef3f9217638bb86439399eac upstream. Add the ISO7816 ioctl and associated accessors and data structure. Drivers can then use this common implementation to handle ISO7816 (smart cards). Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> [ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes] Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-12tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stoppedRazvan Stefanescu
commit 69646d7a3689fbe1a65ae90397d22ac3f1b8d40f upstream. In half-duplex operation, RX should be started after TX completes. If DMA is used, there is a case when the DMA transfer completes but the TX FIFO is not emptied, so the RX cannot be restarted just yet. Use a boolean variable to store this state and rearm TX interrupt mask to be signaled again that the transfer finished. In interrupt transmit handler this variable is used to start RX. A warning message is generated if RX is activated before TX fifo is cleared. Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done") Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-12tty/serial: atmel: Add is_half_duplex helperRazvan Stefanescu
commit f3040983132bf3477acd45d2452a906e67c2fec9 upstream. Use a helper function to check that a port needs to use half duplex communication, replacing several occurrences of multi-line bit checking. Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done") Cc: stable <stable@vger.kernel.org> Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-12tty/serial: atmel: add ISO7816 supportNicolas Ferre
commit 377fedd1866ae3979e4fe36193475b8acbc82784 upstream. When mode is set in atmel_config_iso7816() we backup last RS232 mode for coming back to this mode if requested. Also allow setup of T=0 and T=1 parameter and basic support in set_termios function as well. Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> [ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes] Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07serial: sh-sci: Fix setting SCSCR_TIE while transferring dataHoan Nguyen An
commit 93bcefd4c6bad4c69dbc4edcd3fbf774b24d930d upstream. We disable transmission interrupt (clear SCSCR_TIE) after all data has been transmitted (if uart_circ_empty(xmit)). While transmitting, if the data is still in the tty buffer, re-enable the SCSCR_TIE bit, which was done at sci_start_tx(). This is unnecessary processing, wasting CPU operation if the data transmission length is large. And further, transmit end, FIFO empty bits disabling have also been performed in the step above. Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07serial: mvebu-uart: Fix to avoid a potential NULL pointer dereferenceAditya Pakki
commit 32f47179833b63de72427131169809065db6745e upstream. of_match_device on failure to find a matching device can return a NULL pointer. The patch checks for such a scenrio and passes the error upstream. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07serial: max310x: Fix to avoid potential NULL pointer dereferenceAditya Pakki
commit 3a10e3dd52e80b9a97a3346020024d17b2c272d6 upstream. of_match_device can return a NULL pointer when matching device is not found. This patch avoids a scenario causing NULL pointer derefernce. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07tty: serial: qcom_geni_serial: Initialize baud in qcom_geni_console_setupNathan Chancellor
commit c5cbc78acf693f5605d4a85b1327fa7933daf092 upstream. When building with -Wsometimes-uninitialized, Clang warns: drivers/tty/serial/qcom_geni_serial.c:1079:6: warning: variable 'baud' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] It's not wrong; when options is NULL, baud has no default value. Use 9600 as that is a sane default. Link: https://github.com/ClangBuiltLinux/linux/issues/395 Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07tty: atmel_serial: fix a potential NULL pointer dereferenceKangjie Lu
commit c85be041065c0be8bc48eda4c45e0319caf1d0e5 upstream. In case dmaengine_prep_dma_cyclic fails, the fix returns a proper error code to avoid NULL pointer dereference. Signed-off-by: Kangjie Lu <kjlu@umn.edu> Fixes: 34df42f59a60 ("serial: at91: add rx dma support") Acked-by: Richard Genoud <richard.genoud@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07tty: mxs-auart: fix a potential NULL pointer dereferenceKangjie Lu
commit 6734330654dac550f12e932996b868c6d0dcb421 upstream. In case ioremap fails, the fix returns -ENOMEM to avoid NULL pointer dereferences. Multiple places use port.membase. Signed-off-by: Kangjie Lu <kjlu@umn.edu> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26vt: perform safe console erase in the right orderNicolas Pitre
commit a6dbe442755999960ca54a9b8ecfd9606be0ea75 upstream. Commit 4b4ecd9cb853 ("vt: Perform safe console erase only once") removed what appeared to be an extra call to scr_memsetw(). This missed the fact that set_origin() must be called before clearing the screen otherwise old screen content gets restored on the screen when using vgacon. Let's fix that by moving all the scrollback handling to flush_scrollback() where it logically belongs, and invoking it before the actual screen clearing in csi_J(), making the code simpler in the end. Reported-by: Matthew Whitehead <tedheadster@gmail.com> Signed-off-by: Nicolas Pitre <nico@linaro.org> Tested-by: Matthew Whitehead <tedheadster@gmail.com> Fixes: 4b4ecd9cb853 ("vt: Perform safe console erase only once") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 ↵Jay Dolan
chip use the pci_pericom_setup() commit 78d3820b9bd39028727c6aab7297b63c093db343 upstream. The four port Pericom chips have the fourth port at the wrong address. Make use of quirk to fix it. Fixes: c8d192428f52 ("serial: 8250: added acces i/o products quad and octal serial cards") Cc: stable <stable@vger.kernel.org> Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26serial: 8250_pci: Fix number of ports for ACCES serial cardsJay Dolan
commit b896b03bc7fce43a07012cc6bf5e2ab2fddf3364 upstream. Have the correct number of ports created for ACCES serial cards. Two port cards show up as four ports, and four port cards show up as eight. Fixes: c8d192428f52 ("serial: 8250: added acces i/o products quad and octal serial cards") Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26serial: 8250_of: assume reg-shift of 2 for mrvl,mmp-uartLubomir Rintel
commit f4817843e39ce78aace0195a57d4e8500a65a898 upstream. There are two other drivers that bind to mrvl,mmp-uart and both of them assume register shift of 2 bits. There are device trees that lack the property and rely on that assumption. If this driver wins the race to bind to those devices, it should behave the same as the older deprecated driver. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26serial: uartps: Fix stuck ISR if RX disabled with non-empty FIFOAnssi Hannula
commit 7abab1605139bc41442864c18f9573440f7ca105 upstream. If RX is disabled while there are still unprocessed bytes in RX FIFO, cdns_uart_handle_rx() called from interrupt handler will get stuck in the receive loop as read bytes will not get removed from the RX FIFO and CDNS_UART_SR_RXEMPTY bit will never get set. Avoid the stuck handler by checking first if RX is disabled. port->lock protects against race with RX-disabling functions. This HW behavior was mentioned by Nathan Rossi in 43e98facc4a3 ("tty: xuartps: Fix RX hang, and TX corruption in termios call") which fixed a similar issue in cdns_uart_set_termios(). The behavior can also be easily verified by e.g. setting CDNS_UART_CR_RX_DIS at the beginning of cdns_uart_handle_rx() - the following loop will then get stuck. Resetting the FIFO using RXRST would not set RXEMPTY either so simply issuing a reset after RX-disable would not work. I observe this frequently on a ZynqMP board during heavy RX load at 1M baudrate when the reader process exits and thus RX gets disabled. Fixes: 61ec9016988f ("tty/serial: add support for Xilinx PS UART") Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-16serial: fsl_lpuart: fix maximum acceptable baud rate with over-samplingTomonori Sakita
commit 815d835b7ba46685c316b000013367dacb2b461b upstream. Using over-sampling ratio, lpuart can accept baud rate upto uartclk / 4. Signed-off-by: Tomonori Sakita <tomonori.sakita@sord.co.jp> Signed-off-by: Atsushi Nemoto <atsushi.nemoto@sord.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-01serial: 8250_pci: Make PCI class test non fatalAndy Shevchenko
commit 824d17c57b0abbcb9128fb3f7327fae14761914b upstream. As has been reported the National Instruments serial cards have broken PCI class. The commit 7d8905d06405 ("serial: 8250_pci: Enable device after we check black list") made the PCI class check mandatory for the case when device is listed in a quirk list. Make PCI class test non fatal to allow broken card be enumerated. Fixes: 7d8905d06405 ("serial: 8250_pci: Enable device after we check black list") Cc: stable <stable@vger.kernel.org> Reported-by: Guan Yung Tseng <guan.yung.tseng@ni.com> Tested-by: Guan Yung Tseng <guan.yung.tseng@ni.com> Tested-by: KHUENY.Gerhard <Gerhard.KHUENY@bachmann.info> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-01serial: fix race between flush_to_ldisc and tty_openGreg Kroah-Hartman
commit fedb5760648a291e949f2380d383b5b2d2749b5e upstream. There still is a race window after the commit b027e2298bd588 ("tty: fix data race between tty_init_dev and flush of buf"), and we encountered this crash issue if receive_buf call comes before tty initialization completes in tty_open and tty->driver_data may be NULL. CPU0 CPU1 ---- ---- tty_open tty_init_dev tty_ldisc_unlock schedule flush_to_ldisc receive_buf tty_port_default_receive_buf tty_ldisc_receive_buf n_tty_receive_buf_common __receive_buf uart_flush_chars uart_start /*tty->driver_data is NULL*/ tty->ops->open /*init tty->driver_data*/ it can be fixed by extending ldisc semaphore lock in tty_init_dev to driver_data initialized completely after tty->ops->open(), but this will lead to get lock on one function and unlock in some other function, and hard to maintain, so fix this race only by checking tty->driver_data when receiving, and return if tty->driver_data is NULL, and n_tty_receive_buf_common maybe calls uart_unthrottle, so add the same check. Because the tty layer knows nothing about the driver associated with the device, the tty layer can not do anything here, it is up to the tty driver itself to check for this type of race. Fix up the serial driver to correctly check to see if it is finished binding with the device when being called, and if not, abort the tty calls. [Description and problem report and testing from Li RongQing, I rewrote the patch to be in the serial layer, not in the tty core - gregkh] Reported-by: Li RongQing <lirongqing@baidu.com> Tested-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Wang Li <wangli39@baidu.com> Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-01tty: serial: samsung: Properly set flags in autoCTS modeBeomho Seo
commit 31e933645742ee6719d37573a27cce0761dcf92b upstream. Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support") has changed the way the autoCTS mode is handled. According to that change, serial drivers which enable H/W autoCTS mode must set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling TX. This patch adds proper handling of UPSTAT_AUTOCTS flag. Signed-off-by: Beomho Seo <beomho.seo@samsung.com> [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-01serial: fsl_lpuart: clear parity enable bit when disable parityAndy Duan
commit 397bd9211fe014b347ca8f95a8f4e1017bac1aeb upstream. Current driver only enable parity enable bit and never clear it when user set the termios. The fix clear the parity enable bit when PARENB flag is not set in termios->c_cflag. Cc: Lukas Wunner <lukas@wunner.de> Signed-off-by: Andy Duan <fugang.duan@nxp.com> Reviewed-by: Fabio Estevam <festevam@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-19vt: invoke notifier on screen size changeNicolas Pitre
commit 0c9b1965faddad7534b6974b5b36c4ad37998f8e upstream. User space using poll() on /dev/vcs devices are not awaken when a screen size change occurs. Let's fix that. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-19vt: always call notifier with the console lock heldNicolas Pitre
commit 7e1d226345f89ad5d0216a9092c81386c89b4983 upstream. Every invocation of notify_write() and notify_update() is performed under the console lock, except for one case. Let's fix that. Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-19tty/n_hdlc: fix __might_sleep warningPaul Fulghum
commit fc01d8c61ce02c034e67378cd3e645734bc18c8c upstream. Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE. This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE. The loop breaks out and sets TASK_RUNNING after calling copy_to_user. This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user. [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324 Signed-off-by: Paul Fulghum <paulkf@microgate.com> Reported-by: syzbot <syzbot+c244af085a0159d22879@syzkaller.appspotmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: stable <stable@vger.kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-19tty: Handle problem if line discipline does not have receive_bufGreg Kroah-Hartman
commit 27cfb3a53be46a54ec5e0bd04e51995b74c90343 upstream. Some tty line disciplines do not have a receive buf callback, so properly check for that before calling it. If they do not have this callback, just eat the character quietly, as we can't fail this call. Reported-by: Jann Horn <jannh@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05tty/serial: do not free trasnmit buffer page under port lockSergey Senozhatsky
commit d72402145ace0697a6a9e8e75a3de5bf3375f78d upstream. LKP has hit yet another circular locking dependency between uart console drivers and debugobjects [1]: CPU0 CPU1 rhltable_init() __init_work() debug_object_init uart_shutdown() /* db->lock */ /* uart_port->lock */ debug_print_object() free_page() printk() call_console_drivers() debug_check_no_obj_freed() /* uart_port->lock */ /* db->lock */ debug_print_object() So there are two dependency chains: uart_port->lock -> db->lock And db->lock -> uart_port->lock This particular circular locking dependency can be addressed in several ways: a) One way would be to move debug_print_object() out of db->lock scope and, thus, break the db->lock -> uart_port->lock chain. b) Another one would be to free() transmit buffer page out of db->lock in UART code; which is what this patch does. It makes sense to apply a) and b) independently: there are too many things going on behind free(), none of which depend on uart_port->lock. The patch fixes transmit buffer page free() in uart_shutdown() and, additionally, in uart_port_startup() (as was suggested by Dmitry Safonov). [1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Waiman Long <longman@redhat.com> Cc: Dmitry Safonov <dima@arista.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05serial: set suppress_bind_attrs flag only if builtinAnders Roxell
commit 646097940ad35aa2c1f2012af932d55976a9f255 upstream. When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled, arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init). devtmpfs gets killed because we try to remove a file and decrement the wb reference count before the noop_backing_device_info gets initialized. [ 0.332075] Serial: AMBA PL011 UART driver [ 0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1 [ 0.502382] console [ttyAMA0] enabled [ 0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000 [ 0.516053] Mem abort info: [ 0.516222] ESR = 0x96000004 [ 0.516417] Exception class = DABT (current EL), IL = 32 bits [ 0.516641] SET = 0, FnV = 0 [ 0.516826] EA = 0, S1PTW = 0 [ 0.516984] Data abort info: [ 0.517149] ISV = 0, ISS = 0x00000004 [ 0.517339] CM = 0, WnR = 0 [ 0.517553] [0000800074c12000] user address but active_mm is swapper [ 0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 0.518305] Modules linked in: [ 0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82 [ 0.519307] Hardware name: linux,dummy-virt (DT) [ 0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 0.519959] pc : __destroy_inode+0x94/0x2a8 [ 0.520212] lr : __destroy_inode+0x78/0x2a8 [ 0.520401] sp : ffff0000098c3b20 [ 0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714 [ 0.520904] x27: 0000000000002000 x26: 0000000000002000 [ 0.521179] x25: ffff000009583000 x24: 0000000000000000 [ 0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0 [ 0.521737] x21: ffff0000093f9338 x20: 0000000000000000 [ 0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400 [ 0.522376] x17: 0000000000000000 x16: 0000000000000000 [ 0.522727] x15: 0000000000000400 x14: 0000000000000400 [ 0.523068] x13: 0000000000000001 x12: 0000000000000001 [ 0.523421] x11: 0000000000000000 x10: 0000000000000970 [ 0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190 [ 0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88 [ 0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb [ 0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff [ 0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000 [ 0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____)) [ 0.525529] Call trace: [ 0.525806] __destroy_inode+0x94/0x2a8 [ 0.526108] destroy_inode+0x34/0x88 [ 0.526370] evict+0x144/0x1c8 [ 0.526636] iput+0x184/0x230 [ 0.526871] dentry_unlink_inode+0x118/0x130 [ 0.527152] d_delete+0xd8/0xe0 [ 0.527420] vfs_unlink+0x240/0x270 [ 0.527665] handle_remove+0x1d8/0x330 [ 0.527875] devtmpfsd+0x138/0x1c8 [ 0.528085] kthread+0x14c/0x158 [ 0.528291] ret_from_fork+0x10/0x18 [ 0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04) [ 0.529367] ---[ end trace 5a3dee47727f877c ]--- Rework to set suppress_bind_attrs flag to avoid removing the device when CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and xilinx_uartps as well. Co-developed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05tty: Don't hold ldisc lock in tty_reopen() if ldisc presentDmitry Safonov
commit d3736d82e8169768218ee0ef68718875918091a0 upstream. Try to get reference for ldisc during tty_reopen(). If ldisc present, we don't need to do tty_ldisc_reinit() and lock the write side for line discipline semaphore. Effectively, it optimizes fast-path for tty_reopen(), but more importantly it won't interrupt ongoing IO on the tty as no ldisc change is needed. Fixes user-visible issue when tty_reopen() interrupted login process for user with a long password, observed and reported by Lukas. Fixes: c96cf923a98d ("tty: Don't block on IO when ldisc change is pending") Fixes: 83d817f41070 ("tty: Hold tty_ldisc_lock() during tty_reopen()") Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Lukas F. Hartmann <lukas@mntmn.com> Tested-by: Lukas F. Hartmann <lukas@mntmn.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05tty: Simplify tty->count math in tty_reopen()Dmitry Safonov
commit cf62a1a13749db0d32b5cdd800ea91a4087319de upstream. As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter. Simplify math by increasing the counter after reinit success. Cc: Jiri Slaby <jslaby@suse.com> Link: lkml.kernel.org/r/<20180829022353.23568-2-dima@arista.com> Suggested-by: Jiri Slaby <jslaby@suse.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05tty: Hold tty_ldisc_lock() during tty_reopen()Dmitry Safonov
commit 83d817f41070c48bc3eb7ec18e43000a548fca5c upstream. tty_ldisc_reinit() doesn't race with neither tty_ldisc_hangup() nor set_ldisc() nor tty_ldisc_release() as they use tty lock. But it races with anyone who expects line discipline to be the same after hoding read semaphore in tty_ldisc_ref(). We've seen the following crash on v4.9.108 stable: BUG: unable to handle kernel paging request at 0000000000002260 IP: [..] n_tty_receive_buf_common+0x5f/0x86d Workqueue: events_unbound flush_to_ldisc Call Trace: [..] n_tty_receive_buf2 [..] tty_ldisc_receive_buf [..] flush_to_ldisc [..] process_one_work [..] worker_thread [..] kthread [..] ret_from_fork tty_ldisc_reinit() should be called with ldisc_sem hold for writing, which will protect any reader against line discipline changes. Cc: Jiri Slaby <jslaby@suse.com> Cc: stable@vger.kernel.org # b027e2298bd5 ("tty: fix data race between tty_init_dev and flush of buf") Reviewed-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+3aa9784721dfb90e984d@syzkaller.appspotmail.com Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Dmitry Safonov <dima@arista.com> Tested-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>