Samir Virmani aff9cf5955 uart: Fix crash in uart_write and uart_put_char ... We were experiencing a crash similar to the one reported as part of commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") in our testbed as well. We continue to observe the same crash after integrating the commit a5ba1d95e4 ("uart: fix race between uart_put_char() and uart_shutdown()") On reviewing the change, the port lock should be taken prior to checking for if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer uart_state->xmit. Traceback: [11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference at virtual address 0000003b [11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180 [11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120 [11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>] lr : [<ffffffc0003747cc>] pstate: 000001c5 [11/27/2018 06:24:32.4950] sp : ffffffc076433d30 [11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140 [11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580 [11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140 [11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000 [11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076 [11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000 [11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68 [11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948 [11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333 [11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131 [11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070 [11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b [11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008 [11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e [11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b [11/27/2018 06:24:32.4950] CPU2: stopping [11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P D O 4.1.51 #3 [11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT) [11/27/2018 06:24:32.4950] Call trace: [11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150 [11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20 [11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0 [11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0 [11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90 Fixes: a5ba1d95e4 ("uart: fix race between uart_put_char() and uart_shutdown()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Samir Virmani <samir@embedur.com> Acked-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-01-18 13:03:47 +01:00
..
8250	TTY/Serial driver patches for 4.21-rc1	2018-12-28 20:33:54 -08:00
cpm_uart	mm: remove include/linux/bootmem.h	2018-10-31 08:54:16 -07:00
jsm	tty: serial: jsm: remove redundant pointer ch	2018-07-13 15:36:32 +02:00
21285.c
altera_jtaguart.c
altera_uart.c
amba-pl010.c
amba-pl011.c	serial: set suppress_bind_attrs flag only if builtin	2018-11-09 09:07:17 -08:00
amba-pl011.h
apbuart.c
apbuart.h
ar933x_uart.c
arc_uart.c
atmel_serial.c	tty/serial: atmel: add ISO7816 support	2018-10-02 13:38:55 -07:00
atmel_serial.h	tty/serial: atmel: add ISO7816 support	2018-10-02 13:38:55 -07:00
bcm63xx_uart.c
clps711x.c
digicolor-usart.c
dz.c
dz.h
earlycon-arm-semihost.c
earlycon-riscv-sbi.c	tty/serial: Add RISC-V SBI earlycon support	2019-01-09 14:59:57 -08:00
earlycon.c	earlycon: Remove hardcoded port->uartclk initialization in of_setup_earlycon	2018-05-14 13:41:05 +02:00
efm32-uart.c
fsl_lpuart.c	serial: fsl_lpuart: clear parity enable bit when disable parity	2018-11-09 08:48:57 -08:00
icom.c
icom.h
ifx6x60.c
ifx6x60.h
imx.c	serial: imx: fix error handling in console_setup	2018-11-27 09:56:20 +01:00
ioc3_serial.c
ioc4_serial.c
ip22zilog.c
ip22zilog.h
Kconfig	tty/serial: Add RISC-V SBI earlycon support	2019-01-09 14:59:57 -08:00
kgdb_nmi.c
kgdboc.c	kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()	2018-12-06 15:59:07 +01:00
lantiq.c	serial: lantiq: Do not swap register read/writes	2019-01-08 16:53:36 +01:00
lpc32xx_hs.c
Makefile	tty/serial: Add RISC-V SBI earlycon support	2019-01-09 14:59:57 -08:00
max310x.c	serial: max310x: Fix tx_empty() callback	2018-12-19 13:48:45 +01:00
max3100.c
mcf.c
men_z135_uart.c
meson_uart.c
mpc52xx_uart.c
mps2-uart.c
mpsc.c
msm_serial.c	tty: serial: msm_serial: Add __maybe_unused to suspend/resume callbacks	2018-05-14 13:41:05 +02:00
mux.c
mvebu-uart.c	serial: mvebu-uart: initialize over sampling stack register	2018-11-27 09:20:17 +01:00
mxs-auart.c	serial: mxs-auart: Fix potential infinite loop	2018-09-18 16:07:24 +02:00
netx-serial.c
omap-serial.c
owl-uart.c
pch_uart.c	pch_uart: remove set but not used variable 'tx_empty'	2018-11-09 09:07:17 -08:00
pic32_uart.c	serial: set suppress_bind_attrs flag only if builtin	2018-11-09 09:07:17 -08:00
pic32_uart.h
pmac_zilog.c	tty: Use of_node_name_{eq,prefix} for node name comparisons	2018-12-17 16:12:17 +01:00
pmac_zilog.h
pnx8xxx_uart.c
pxa.c	serial: pxa: Fix an error handling path in 'serial_pxa_probe()'	2018-06-28 21:07:54 +09:00
qcom_geni_serial.c	tty: serial: qcom_geni_serial: Fix UART hang	2018-12-20 16:26:28 +01:00
rda-uart.c	tty: serial: Add RDA8810PL UART driver	2018-12-31 13:10:01 -08:00
rp2.c	treewide: devm_kzalloc() -> devm_kcalloc()	2018-06-12 16:19:22 -07:00
sa1100.c
samsung.c	tty: serial: samsung: Increase maximum baudrate	2018-12-17 16:16:28 +01:00
samsung.h
sb1250-duart.c
sc16is7xx.c	sc16is7xx: Fix for "Unexpected interrupt: 8"	2018-09-18 16:07:25 +02:00
sccnxp.c	serial: sccnxp: Allow to use non-standard baud rates	2018-12-20 16:26:59 +01:00
serial_core.c	uart: Fix crash in uart_write and uart_put_char	2019-01-18 13:03:47 +01:00
serial_ks8695.c
serial_mctrl_gpio.c	gpiolib: Pass array info to get/set array functions	2018-09-13 11:16:54 +02:00
serial_mctrl_gpio.h
serial_txx9.c
serial-tegra.c	serial: tegra: fix some spelling mistakes	2018-11-09 08:58:18 -08:00
sh-sci.c	serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failure	2018-12-17 15:04:11 +01:00
sh-sci.h	serial: sh-sci: Support for HSCIF RX sampling point adjustment	2018-04-23 10:08:18 +02:00
sirfsoc_uart.c
sirfsoc_uart.h
sn_console.c	TTY: sn_console: Replace spin_is_locked() with spin_trylock()	2018-10-04 11:06:35 -07:00
sprd_serial.c	serial: sprd: Fix the indentation issue	2018-09-18 16:07:24 +02:00
st-asc.c	tty: serial: simplify getting .drvdata	2018-04-22 17:29:43 +02:00
stm32-usart.c
stm32-usart.h
suncore.c	tty: Use of_node_name_{eq,prefix} for node name comparisons	2018-12-17 16:12:17 +01:00
sunhv.c
sunsab.c	treewide: kzalloc() -> kcalloc()	2018-06-12 16:19:22 -07:00
sunsab.h
sunsu.c	TTY/Serial driver patches for 4.21-rc1	2018-12-28 20:33:54 -08:00
sunzilog.c
sunzilog.h
timbuart.c
timbuart.h
uartlite.c	serial-uartlite: fix null pointer dereference on pointer port	2018-11-27 09:08:15 +01:00
ucc_uart.c
vr41xx_siu.c
vt8500_serial.c
xilinx_uartps.c	serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly	2018-12-19 08:23:20 +01:00
zs.c
zs.h