user/sven/linux.git/drivers/tty, branch v4.9.293

serial: core: fix transmit-buffer reset and memleak

2021-12-08T07:45:07Z

commit 00de977f9e0aa9760d9a79d1e41ff780f74e3424 upstream. Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close. Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted. Furthermore, the buffer of any port that has been opened would leak on driver unbind. Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()"). Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace ("tty/serial: do not free trasnmit buffer page under port lock")). Link: https://lore.kernel.org/r/319321886d97c456203d5c6a576a5480d07c3478.1635781688.git.baruch@tkos.co.il Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Cc: stable@vger.kernel.org # 4.9 Cc: Rob Herring Reported-by: Baruch Siach Tested-by: Baruch Siach Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20211108085431.12637-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

serial: pl011: Add ACPI SBSA UART match id

2021-12-08T07:45:07Z

commit ac442a077acf9a6bf1db4320ec0c3f303be092b3 upstream. The document 'ACPI for Arm Components 1.0' defines the following _HID mappings: -'Prime cell UART (PL011)': ARMH0011 -'SBSA UART': ARMHB000 Use the sbsa-uart driver when a device is described with the 'ARMHB000' _HID. Note: PL011 devices currently use the sbsa-uart driver instead of the uart-pl011 driver. Indeed, PL011 devices are not bound to a clock in ACPI. It is not possible to change their baudrate. Cc: Signed-off-by: Pierre Gondois Link: https://lore.kernel.org/r/20211109172248.19061-1-Pierre.Gondois@arm.com Signed-off-by: Greg Kroah-Hartman

tty: serial: msm_serial: Deactivate RX DMA for polling support

2021-12-08T07:45:07Z

commit 7492ffc90fa126afb67d4392d56cb4134780194a upstream. The CONSOLE_POLLING mode is used for tools like k(g)db. In this kind of setup, it is often sharing a serial device with the normal system console. This is usually no problem because the polling helpers can consume input values directly (when in kgdb context) and the normal Linux handlers can only consume new input values after kgdb switched back. This is not true anymore when RX DMA is enabled for UARTDM controllers. Single input values can no longer be received correctly. Instead following seems to happen: * on 1. input, some old input is read (continuously) * on 2. input, two old inputs are read (continuously) * on 3. input, three old input values are read (continuously) * on 4. input, 4 previous inputs are received This repeats then for each group of 4 input values. This behavior changes slightly depending on what state the controller was when the first input was received. But this makes working with kgdb basically impossible because control messages are always corrupted when kgdboc tries to parse them. RX DMA should therefore be off when CONSOLE_POLLING is enabled to avoid these kind of problems. No such problem was noticed for TX DMA. Fixes: 99693945013a ("tty: serial: msm: Add RX DMA support") Cc: stable@vger.kernel.org Signed-off-by: Sven Eckelmann Link: https://lore.kernel.org/r/20211113121050.7266-1-sven@narfation.org Signed-off-by: Greg Kroah-Hartman

tty: hvc: replace BUG_ON() with negative return value

2021-12-08T07:45:05Z

commit e679004dec37566f658a255157d3aed9d762a2b7 upstream. Xen frontends shouldn't BUG() in case of illegal data received from their backends. So replace the BUG_ON()s when reading illegal data from the ring page with negative return values. Reviewed-by: Jan Beulich Signed-off-by: Juergen Gross Link: https://lore.kernel.org/r/20210707091045.460-1-jgross@suse.com Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc

2021-11-26T10:48:40Z

[ Upstream commit 3968ddcf05fb4b9409cd1859feb06a5b0550a1c1 ] When running ltp testcase(ltp/testcases/kernel/pty/pty04.c) with arm64, there is a soft lockup, which look like this one: Workqueue: events_unbound flush_to_ldisc Call trace: dump_backtrace+0x0/0x1ec show_stack+0x24/0x30 dump_stack+0xd0/0x128 panic+0x15c/0x374 watchdog_timer_fn+0x2b8/0x304 __run_hrtimer+0x88/0x2c0 __hrtimer_run_queues+0xa4/0x120 hrtimer_interrupt+0xfc/0x270 arch_timer_handler_phys+0x40/0x50 handle_percpu_devid_irq+0x94/0x220 __handle_domain_irq+0x88/0xf0 gic_handle_irq+0x84/0xfc el1_irq+0xc8/0x180 slip_unesc+0x80/0x214 [slip] tty_ldisc_receive_buf+0x64/0x80 tty_port_default_receive_buf+0x50/0x90 flush_to_ldisc+0xbc/0x110 process_one_work+0x1d4/0x4b0 worker_thread+0x180/0x430 kthread+0x11c/0x120 In the testcase pty04, The first process call the write syscall to send data to the pty master. At the same time, the workqueue will do the flush_to_ldisc to pop data in a loop until there is no more data left. When the sender and workqueue running in different core, the sender sends data fastly in full time which will result in workqueue doing work in loop for a long time and occuring softlockup in flush_to_ldisc with kernel configured without preempt. So I add need_resched check and cond_resched in the flush_to_ldisc loop to avoid it. Signed-off-by: Guanghui Feng Link: https://lore.kernel.org/r/1633961304-24759-1-git-send-email-guanghuifeng@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: xilinx_uartps: Fix race condition causing stuck TX

2021-11-26T10:48:37Z

[ Upstream commit 88b20f84f0fe47409342669caf3e58a3fc64c316 ] xilinx_uartps .start_tx() clears TXEMPTY when enabling TXEMPTY to avoid any previous TXEVENT event asserting the UART interrupt. This clear operation is done immediately after filling the TX FIFO. However, if the bytes inserted by cdns_uart_handle_tx() are consumed by the UART before the TXEMPTY is cleared, the clear operation eats the new TXEMPTY event as well, causing cdns_uart_isr() to never receive the TXEMPTY event. If there are bytes still queued in circbuf, TX will get stuck as they will never get transferred to FIFO (unless new bytes are queued to circbuf in which case .start_tx() is called again). While the racy missed TXEMPTY occurs fairly often with short data sequences (e.g. write 1 byte), in those cases circbuf is usually empty so no action on TXEMPTY would have been needed anyway. On the other hand, longer data sequences make the race much more unlikely as UART takes longer to consume the TX FIFO. Therefore it is rare for this race to cause visible issues in general. Fix the race by clearing the TXEMPTY bit in ISR *before* filling the FIFO. The TXEMPTY bit in ISR will only get asserted at the exact moment the TX FIFO *becomes* empty, so clearing the bit before filling FIFO does not cause an extra immediate assertion even if the FIFO is initially empty. This is hard to reproduce directly on a normal system, but inserting e.g. udelay(200) after cdns_uart_handle_tx(port), setting 4000000 baud, and then running "dd if=/dev/zero bs=128 of=/dev/ttyPS0 count=50" reliably reproduces the issue on my ZynqMP test system unless this fix is applied. Fixes: 85baf542d54e ("tty: xuartps: support 64 byte FIFO size") Signed-off-by: Anssi Hannula Link: https://lore.kernel.org/r/20211026102741.2910441-1-anssi.hannula@bitwise.fi Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_dw: Drop wrong use of ACPI_PTR()

2021-11-26T10:48:37Z

[ Upstream commit ebabb77a2a115b6c5e68f7364b598310b5f61fb2 ] ACPI_PTR() is more harmful than helpful. For example, in this case if CONFIG_ACPI=n, the ID table left unused which is not what we want. Instead of adding ifdeffery here and there, drop ACPI_PTR(). Fixes: 6a7320c4669f ("serial: 8250_dw: Add ACPI 5.0 support") Reported-by: Daniel Palmer Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211005134516.23218-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: core: Fix initializing and restoring termios speed

2021-11-26T10:48:25Z

commit 027b57170bf8bb6999a28e4a5f3d78bf1db0f90c upstream. Since commit edc6afc54968 ("tty: switch to ktermios and new framework") termios speed is no longer stored only in c_cflag member but also in new additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag then termios speed is stored only in these new members. Therefore to correctly restore termios speed it is required to store also ispeed and ospeed members, not only cflag member. In case only cflag member with BOTHER flag is restored then functions tty_termios_baud_rate() and tty_termios_input_baud_rate() returns baudrate stored in c_ospeed / c_ispeed member, which is zero as it was not restored too. If reported baudrate is invalid (e.g. zero) then serial core functions report fallback baudrate value 9600. So it means that in this case original baudrate is lost and kernel changes it to value 9600. Simple reproducer of this issue is to boot kernel with following command line argument: "console=ttyXXX,86400" (where ttyXXX is the device name). For speed 86400 there is no Bnnn constant and therefore kernel has to represent this speed via BOTHER c_cflag. Which means that speed is stored only in c_ospeed and c_ispeed members, not in c_cflag anymore. If bootloader correctly configures serial device to speed 86400 then kernel prints boot log to early console at speed speed 86400 without any issue. But after kernel starts initializing real console device ttyXXX then speed is changed to fallback value 9600 because information about speed was lost. This patch fixes above issue by storing and restoring also ispeed and ospeed members, which are required for BOTHER flag. Fixes: edc6afc54968 ("[PATCH] tty: switch to ktermios and new framework") Cc: stable@vger.kernel.org Signed-off-by: Pali Rohár Link: https://lore.kernel.org/r/20211002130900.9518-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: Fix out-of-bound vmalloc access in imageblit

2021-10-06T08:23:41Z

[ Upstream commit 3b0c406124719b625b1aba431659f5cdc24a982c ] This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values. If this struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(), leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value, eventually, causes the imageblit to access an out-of-bound address value. To solve this issue I made the resize_screen() be called even if the screen does not need any resizing, so it will "fix and fill" the fb_var_screeninfo independently. Cc: stable # after 5.15-rc2 is out, give it time to bake Reported-and-tested-by: syzbot+858dc7a2f7ef07c2c219@syzkaller.appspotmail.com Signed-off-by: Igor Matheus Andrade Torrente Link: https://lore.kernel.org/r/20210628134509.15895-1-igormtorrente@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: mvebu-uart: fix driver's tx_empty callback

2021-10-06T08:23:39Z

commit 74e1eb3b4a1ef2e564b4bdeb6e92afe844e900de upstream. Driver's tx_empty callback should signal when the transmit shift register is empty. So when the last character has been sent. STAT_TX_FIFO_EMP bit signals only that HW transmit FIFO is empty, which happens when the last byte is loaded into transmit shift register. STAT_TX_EMP bit signals when the both HW transmit FIFO and transmit shift register are empty. So replace STAT_TX_FIFO_EMP check by STAT_TX_EMP in mvebu_uart_tx_empty() callback function. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable Signed-off-by: Pali Rohár Link: https://lore.kernel.org/r/20210911132017.25505-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman