diff options
| author | Ben Hutchings <ben@decadent.org.uk> | 2013-10-06 20:05:46 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-16 16:01:44 -0400 |
| commit | 8eaede49dfdc1ff1d727f9c913665b8009945191 (patch) | |
| tree | 094c592c127142c4f01766fb82e3a7973c87ca1c /Documentation/sysrq.txt | |
| parent | e8b5cbb041130ef297c90f8af2d3d45dfb9e6d15 (diff) | |
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>
Diffstat (limited to 'Documentation/sysrq.txt')
| -rw-r--r-- | Documentation/sysrq.txt | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt index 1c0471dc70fe..0e307c94809a 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt | |||
| @@ -11,11 +11,9 @@ regardless of whatever else it is doing, unless it is completely locked up. | |||
| 11 | You need to say "yes" to 'Magic SysRq key (CONFIG_MAGIC_SYSRQ)' when | 11 | You need to say "yes" to 'Magic SysRq key (CONFIG_MAGIC_SYSRQ)' when |
| 12 | configuring the kernel. When running a kernel with SysRq compiled in, | 12 | configuring the kernel. When running a kernel with SysRq compiled in, |
| 13 | /proc/sys/kernel/sysrq controls the functions allowed to be invoked via | 13 | /proc/sys/kernel/sysrq controls the functions allowed to be invoked via |
| 14 | the SysRq key. By default the file contains 1 which means that every | 14 | the SysRq key. The default value in this file is set by the |
| 15 | possible SysRq request is allowed (in older versions SysRq was disabled | 15 | CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE config symbol, which itself defaults |
| 16 | by default, and you were required to specifically enable it at run-time | 16 | to 1. Here is the list of possible values in /proc/sys/kernel/sysrq: |
| 17 | but this is not the case any more). Here is the list of possible values | ||
| 18 | in /proc/sys/kernel/sysrq: | ||
| 19 | 0 - disable sysrq completely | 17 | 0 - disable sysrq completely |
| 20 | 1 - enable all functions of sysrq | 18 | 1 - enable all functions of sysrq |
| 21 | >1 - bitmask of allowed sysrq functions (see below for detailed function | 19 | >1 - bitmask of allowed sysrq functions (see below for detailed function |
| @@ -32,8 +30,9 @@ in /proc/sys/kernel/sysrq: | |||
| 32 | You can set the value in the file by the following command: | 30 | You can set the value in the file by the following command: |
| 33 | echo "number" >/proc/sys/kernel/sysrq | 31 | echo "number" >/proc/sys/kernel/sysrq |
| 34 | 32 | ||
| 35 | The number may be written either as decimal or as hexadecimal with the | 33 | The number may be written here either as decimal or as hexadecimal |
| 36 | 0x prefix. | 34 | with the 0x prefix. CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE must always be |
| 35 | written in hexadecimal. | ||
| 37 | 36 | ||
| 38 | Note that the value of /proc/sys/kernel/sysrq influences only the invocation | 37 | Note that the value of /proc/sys/kernel/sysrq influences only the invocation |
| 39 | via a keyboard. Invocation of any operation via /proc/sysrq-trigger is always | 38 | via a keyboard. Invocation of any operation via /proc/sysrq-trigger is always |