linux-stable.git/drivers/tty, branch linux-5.14.y

serial: cpm_uart: Protect udbg definitions by CONFIG_SERIAL_CPM_CONSOLE

2021-11-17T10:04:31+00:00

[ Upstream commit d142585bceb3218ad432ed0fcd5be9d6e3cd9052 ]

If CONFIG_CONSOLE_POLL=y, and CONFIG_SERIAL_CPM=m (hence
CONFIG_SERIAL_CPM_CONSOLE=n):

    drivers/tty/serial/cpm_uart/cpm_uart_core.c:1109:12: warning: ‘udbg_cpm_getc’ defined but not used [-Wunused-function]
     1109 | static int udbg_cpm_getc(void)
	  |            ^~~~~~~~~~~~~
    drivers/tty/serial/cpm_uart/cpm_uart_core.c:1095:13: warning: ‘udbg_cpm_putc’ defined but not used [-Wunused-function]
     1095 | static void udbg_cpm_putc(char c)
	  |             ^~~~~~~~~~~~~

Fix this by making the udbg definitions depend on
CONFIG_SERIAL_CPM_CONSOLE, in addition to CONFIG_CONSOLE_POLL.

Fixes: a60526097f42eb98 ("tty: serial: cpm_uart: Add udbg support for enabling xmon")
Signed-off-by: Geert Uytterhoeven 
Link: https://lore.kernel.org/r/20211027075326.3270785-1-geert@linux-m68k.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: xilinx_uartps: Fix race condition causing stuck TX

2021-11-17T10:04:29+00:00

[ 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: imx: fix detach/attach of serial console

2021-11-17T10:04:27+00:00

[ Upstream commit 6d0d1b5a1b4870911beb89544ec1a9751c42fec7 ]

If the device used as a serial console gets detached/attached at runtime,
register_console() will try to call imx_uart_setup_console(), but this
is not possible since it is marked as __init.

For instance

  # cat /sys/devices/virtual/tty/console/active
  tty1 ttymxc0
  # echo -n N > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console
  # echo -n Y > /sys/devices/virtual/tty/console/subsystem/ttymxc0/console

[   73.166649] 8<--- cut here ---
[   73.167005] Unable to handle kernel paging request at virtual address c154d928
[   73.167601] pgd = 55433e84
[   73.167875] [c154d928] *pgd=8141941e(bad)
[   73.168304] Internal error: Oops: 8000000d [#1] SMP ARM
[   73.168429] Modules linked in:
[   73.168522] CPU: 0 PID: 536 Comm: sh Not tainted 5.15.0-rc6-00056-g3968ddcf05fb #3
[   73.168675] Hardware name: Freescale i.MX6 Ultralite (Device Tree)
[   73.168791] PC is at imx_uart_console_setup+0x0/0x238
[   73.168927] LR is at try_enable_new_console+0x98/0x124
[   73.169056] pc : []    lr : []    psr: a0000013
[   73.169178] sp : c2ef5e70  ip : 00000000  fp : 00000000
[   73.169281] r10: 00000000  r9 : c02cf970  r8 : 00000000
[   73.169389] r7 : 00000001  r6 : 00000001  r5 : c1760164  r4 : c1e0fb08
[   73.169512] r3 : c154d928  r2 : 00000000  r1 : efffcbd1  r0 : c1760164
[   73.169641] Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[   73.169782] Control: 10c5387d  Table: 8345406a  DAC: 00000051
[   73.169895] Register r0 information: non-slab/vmalloc memory
[   73.170032] Register r1 information: non-slab/vmalloc memory
[   73.170158] Register r2 information: NULL pointer
[   73.170273] Register r3 information: non-slab/vmalloc memory
[   73.170397] Register r4 information: non-slab/vmalloc memory
[   73.170521] Register r5 information: non-slab/vmalloc memory
[   73.170647] Register r6 information: non-paged memory
[   73.170771] Register r7 information: non-paged memory
[   73.170892] Register r8 information: NULL pointer
[   73.171009] Register r9 information: non-slab/vmalloc memory
[   73.171142] Register r10 information: NULL pointer
[   73.171259] Register r11 information: NULL pointer
[   73.171375] Register r12 information: NULL pointer
[   73.171494] Process sh (pid: 536, stack limit = 0xcd1ba82f)
[   73.171621] Stack: (0xc2ef5e70 to 0xc2ef6000)
[   73.171731] 5e60:                                     ???????? ???????? ???????? ????????
[   73.171899] 5e80: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.172059] 5ea0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.172217] 5ec0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.172377] 5ee0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.172537] 5f00: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.172698] 5f20: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.172856] 5f40: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.173016] 5f60: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.173177] 5f80: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.173336] 5fa0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.173496] 5fc0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.173654] 5fe0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.173826] [] (try_enable_new_console) from [] (register_console+0x10c/0x2ec)
[   73.174053] [] (register_console) from [] (console_store+0x14c/0x168)
[   73.174262] [] (console_store) from [] (kernfs_fop_write_iter+0x110/0x1cc)
[   73.174470] [] (kernfs_fop_write_iter) from [] (vfs_write+0x31c/0x548)
[   73.174679] [] (vfs_write) from [] (ksys_write+0x60/0xec)
[   73.174863] [] (ksys_write) from [] (ret_fast_syscall+0x0/0x1c)
[   73.175052] Exception stack(0xc2ef5fa8 to 0xc2ef5ff0)
[   73.175167] 5fa0:                   ???????? ???????? ???????? ???????? ???????? ????????
[   73.175327] 5fc0: ???????? ???????? ???????? ???????? ???????? ???????? ???????? ????????
[   73.175486] 5fe0: ???????? ???????? ???????? ????????
[   73.175608] Code: 00000000 00000000 00000000 00000000 (00000000)
[   73.175744] ---[ end trace 9b75121265109bf1 ]---

A similar issue could be triggered by unbinding/binding the serial
console device [*].

Drop __init so that imx_uart_setup_console() can be safely called at
runtime.

[*] https://lore.kernel.org/all/20181114174940.7865-3-stefan@agner.ch/

Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console")
Reviewed-by: Andy Shevchenko 
Acked-by: Uwe Kleine-König 
Signed-off-by: Stefan Agner 
Signed-off-by: Francesco Dolcini 
Link: https://lore.kernel.org/r/20211020192643.476895-2-francesco.dolcini@toradex.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

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

2021-11-17T10:04:25+00:00

[ 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: 8250: fix racy uartclk update

2021-11-17T10:03:42+00:00

commit 211cde4f5817dc88ef7f8f2fa286e57fbf14c8ee upstream.

Commit 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method")
added a hack to support SoCs where the UART reference clock can
change behind the back of the driver but failed to add the proper
locking.

First, make sure to take a reference to the tty struct to avoid
dereferencing a NULL pointer if the clock change races with a hangup.

Second, the termios semaphore must be held during the update to prevent
a racing termios change.

Fixes: 868f3ee6e452 ("serial: 8250: Add 8250 port clock update method")
Fixes: c8dff3aa8241 ("serial: 8250: Skip uninitialized TTY port baud rate update")
Cc: stable@vger.kernel.org      # 5.9
Cc: Serge Semin 
Tested-by: Serge Semin 
Reviewed-by: Serge Semin 
Acked-by: Andy Shevchenko 
Signed-off-by: Johan Hovold 
Link: https://lore.kernel.org/r/20211015111422.1027-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: core: Fix initializing and restoring termios speed

2021-11-17T10:03:39+00:00

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

2021-10-07T05:53:04+00:00

[ 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

tty: synclink_gt: rename a conflicting function name

2021-09-30T08:13:01+00:00

[ Upstream commit 06e49073dfba24df4b1073a068631b13a0039c34 ]

'set_signals()' in synclink_gt.c conflicts with an exported symbol
in arch/um/, so change set_signals() to set_gtsignals(). Keep
the function names similar by also changing get_signals() to
get_gtsignals().

../drivers/tty/synclink_gt.c:442:13: error: conflicting types for ‘set_signals’
 static void set_signals(struct slgt_info *info);
             ^~~~~~~~~~~
In file included from ../include/linux/irqflags.h:16:0,
                 from ../include/linux/spinlock.h:58,
                 from ../include/linux/mm_types.h:9,
                 from ../include/linux/buildid.h:5,
                 from ../include/linux/module.h:14,
                 from ../drivers/tty/synclink_gt.c:46:
../arch/um/include/asm/irqflags.h:6:5: note: previous declaration of ‘set_signals’ was here
 int set_signals(int enable);
     ^~~~~~~~~~~

Fixes: 705b6c7b34f2 ("[PATCH] new driver synclink_gt")
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: Paul Fulghum 
Signed-off-by: Randy Dunlap 
Link: https://lore.kernel.org/r/20210902003806.17054-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

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

2021-09-30T08:12:56+00:00

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

serial: 8250: 8250_omap: Fix RX_LVL register offset

2021-09-30T08:12:56+00:00

commit 79e9e30a9292a62d25ab75488d3886108db1eaad upstream.

Commit b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt
storm on K3 SoCs") introduced fixup including a register read to
RX_LVL, however, we should be using word offset than byte offset
since our registers are on 4 byte boundary (port.regshift = 2) for
8250_omap.

Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs")
Cc: stable 
Cc: Jan Kiszka 
Cc: Vignesh Raghavendra 
Signed-off-by: Nishanth Menon 
Link: https://lore.kernel.org/r/20210903050550.29050-1-nm@ti.com
Signed-off-by: Greg Kroah-Hartman