Commit 732dbf3a authored by Felix Fietkau's avatar Felix Fietkau Committed by Greg Kroah-Hartman
Browse files

serial: do not accept sysrq characters via serial port 



many embedded boards have a disconnected TTL level serial which can
generate some garbage that can lead to spurious false sysrq detects.

Signed-off-by: default avatarJohn Crispin <john@phrozen.org>
Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 552df698

include/linux/serial_core.h

+1 −1
Original line number Diff line number Diff line
@@ -450,7 +450,7 @@ extern void uart_handle_cts_change(struct uart_port *uport, 
extern void uart_insert_char(struct uart_port *port, unsigned int status,

		 unsigned int overrun, unsigned int ch, unsigned int flag);



#ifdef SUPPORT_SYSRQ

#if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL)

static inline int

uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)

{

lib/Kconfig.debug

+10 −0
Original line number Diff line number Diff line
@@ -416,6 +416,16 @@ config MAGIC_SYSRQ_DEFAULT_ENABLE 
	  This may be set to 1 or 0 to enable or disable them all, or

	  to a bitmask as described in Documentation/sysrq.txt.



config MAGIC_SYSRQ_SERIAL

	bool "Enable magic SysRq key over serial"

	depends on MAGIC_SYSRQ

	default y

	help

	  Many embedded boards have a disconnected TTL level serial which can

	  generate some garbage that can lead to spurious false sysrq detects.

	  This option allows you to decide whether you want to enable the

	  magic SysRq key.



config DEBUG_KERNEL

	bool "Kernel debugging"

	help

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