sysrq: Allow magic SysRq key functions to be disabled through Kconfig

Turn the initial value of sysctl kernel.sysrq (SYSRQ_DEFAULT_ENABLE)
into a Kconfig variable.

Original version by Bastian Blank <waldi@debian.org>.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 06344d986eb9..29329374ff0d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -312,6 +312,15 @@ config MAGIC_SYSRQ
           keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
           unless you really know what this hack does.
 
+config MAGIC_SYSRQ_DEFAULT_ENABLE
+        hex "Enable magic SysRq key functions by default"
+        depends on MAGIC_SYSRQ
+        default 0x1
+        help
+          Specifies which SysRq key functions are enabled by default.
+          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 DEBUG_KERNEL
         bool "Kernel debugging"
         help