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In kgdb context, calling console handlers aren't safe due to locks used in those handlers which could in turn lead to a deadlock. Although, using oops_in_progress increases the chance to bypass locks in most console handlers but it might not be sufficient enough in case a console uses more locks (VT/TTY is good example). Currently when a driver provides both polling I/O and a console then kdb will output using the console. We can increase robustness by using the currently active polling I/O driver (which should be lockless) instead of the corresponding console. For several common cases (e.g. an embedded system with a single serial port that is used both for console output and debugger I/O) this will result in no console handler being used. In order to achieve this we need to reverse the order of preference to use dbg_io_ops (uses polling I/O mode) over console APIs. So we just store "struct console" that represents debugger I/O in dbg_io_ops and while emitting kdb messages, skip console that matches dbg_io_ops console in order to avoid duplicate messages. After this change, "is_console" param becomes redundant and hence removed. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Link: https://lore.kernel.org/r/1591264879-25920-5-git-send-email-sumit.garg@linaro.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> |
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.. | ||
8250 | ||
cpm_uart | ||
jsm | ||
21285.c | ||
altera_jtaguart.c | ||
altera_uart.c | ||
amba-pl010.c | ||
amba-pl011.c | ||
amba-pl011.h | ||
apbuart.c | ||
apbuart.h | ||
ar933x_uart.c | ||
arc_uart.c | ||
atmel_serial.c | ||
atmel_serial.h | ||
bcm63xx_uart.c | ||
clps711x.c | ||
digicolor-usart.c | ||
dz.c | ||
dz.h | ||
earlycon-arm-semihost.c | ||
earlycon-riscv-sbi.c | ||
earlycon.c | ||
efm32-uart.c | ||
fsl_linflexuart.c | ||
fsl_lpuart.c | ||
icom.c | ||
icom.h | ||
ifx6x60.c | ||
ifx6x60.h | ||
imx.c | ||
ip22zilog.c | ||
ip22zilog.h | ||
Kconfig | ||
kgdb_nmi.c | ||
kgdboc.c | ||
lantiq.c | ||
lpc32xx_hs.c | ||
Makefile | ||
max310x.c | ||
max3100.c | ||
mcf.c | ||
men_z135_uart.c | ||
meson_uart.c | ||
milbeaut_usio.c | ||
mpc52xx_uart.c | ||
mps2-uart.c | ||
msm_serial.c | ||
mux.c | ||
mvebu-uart.c | ||
mxs-auart.c | ||
omap-serial.c | ||
owl-uart.c | ||
pch_uart.c | ||
pic32_uart.c | ||
pic32_uart.h | ||
pmac_zilog.c | ||
pmac_zilog.h | ||
pnx8xxx_uart.c | ||
pxa.c | ||
qcom_geni_serial.c | ||
rda-uart.c | ||
rp2.c | ||
sa1100.c | ||
samsung_tty.c | ||
sb1250-duart.c | ||
sc16is7xx.c | ||
sccnxp.c | ||
serial-tegra.c | ||
serial_core.c | ||
serial_mctrl_gpio.c | ||
serial_mctrl_gpio.h | ||
serial_txx9.c | ||
sh-sci.c | ||
sh-sci.h | ||
sifive.c | ||
sirfsoc_uart.c | ||
sirfsoc_uart.h | ||
sprd_serial.c | ||
st-asc.c | ||
stm32-usart.c | ||
stm32-usart.h | ||
suncore.c | ||
sunhv.c | ||
sunsab.c | ||
sunsab.h | ||
sunsu.c | ||
sunzilog.c | ||
sunzilog.h | ||
tegra-tcu.c | ||
timbuart.c | ||
timbuart.h | ||
uartlite.c | ||
ucc_uart.c | ||
vr41xx_siu.c | ||
vt8500_serial.c | ||
xilinx_uartps.c | ||
zs.c | ||
zs.h |