Commit b8017177 authored by Daniel Thompson's avatar Daniel Thompson Committed by Jason Wessel
Browse files

kdb: Allow access to sensitive commands to be restricted by default 



Currently kiosk mode must be explicitly requested by the bootloader or
userspace. It is convenient to be able to change the default value in a
similar manner to CONFIG_MAGIC_SYSRQ_DEFAULT_MASK.

Signed-off-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: default avatarJason Wessel <jason.wessel@windriver.com>
parent 420c2b1b

kernel/debug/kdb/kdb_main.c

+1 −1
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ 
#undef	MODULE_PARAM_PREFIX

#define	MODULE_PARAM_PREFIX "kdb."



static int kdb_cmd_enabled;

static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;

module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);



#define GREP_LEN 256

lib/Kconfig.kgdb

+25 −0
Original line number Diff line number Diff line
@@ -73,6 +73,31 @@ config KGDB_KDB 
	help

	  KDB frontend for kernel



config KDB_DEFAULT_ENABLE

	hex "KDB: Select kdb command functions to be enabled by default"

	depends on KGDB_KDB

	default 0x1

	help

	  Specifiers which kdb commands are enabled by default. This may

	  be set to 1 or 0 to enable all commands or disable almost all

	  commands.



	  Alternatively the following bitmask applies:



	    0x0002 - allow arbitrary reads from memory and symbol lookup

	    0x0004 - allow arbitrary writes to memory

	    0x0008 - allow current register state to be inspected

	    0x0010 - allow current register state to be modified

	    0x0020 - allow passive inspection (backtrace, process list, lsmod)

	    0x0040 - allow flow control management (breakpoint, single step)

	    0x0080 - enable signalling of processes

	    0x0100 - allow machine to be rebooted



	  The config option merely sets the default at boot time. Both

	  issuing 'echo X > /sys/module/kdb/parameters/cmd_enable' or

          setting with kdb.cmd_enable=X kernel command line option will

	  override the default settings.



config KDB_KEYBOARD

	bool "KGDB_KDB: keyboard as input device"

	depends on VT && KGDB_KDB