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| author | Ben Hutchings <ben@decadent.org.uk> | 2013-10-07 01:05:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-16 13:01:44 -0700 |
| commit | 8eaede49dfdc1ff1d727f9c913665b8009945191 (patch) | |
| tree | 094c592c127142c4f01766fb82e3a7973c87ca1c /Documentation/sysrq.txt | |
| parent | e8b5cbb041130ef297c90f8af2d3d45dfb9e6d15 (diff) | |
| download | linux-8eaede49dfdc1ff1d727f9c913665b8009945191.tar.bz2 | |
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. You need to say "yes" to 'Magic SysRq key (CONFIG_MAGIC_SYSRQ)' when configuring the kernel. When running a kernel with SysRq compiled in, /proc/sys/kernel/sysrq controls the functions allowed to be invoked via -the SysRq key. By default the file contains 1 which means that every -possible SysRq request is allowed (in older versions SysRq was disabled -by default, and you were required to specifically enable it at run-time -but this is not the case any more). Here is the list of possible values -in /proc/sys/kernel/sysrq: +the SysRq key. The default value in this file is set by the +CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE config symbol, which itself defaults +to 1. Here is the list of possible values in /proc/sys/kernel/sysrq: 0 - disable sysrq completely 1 - enable all functions of sysrq >1 - bitmask of allowed sysrq functions (see below for detailed function @@ -32,8 +30,9 @@ in /proc/sys/kernel/sysrq: You can set the value in the file by the following command: echo "number" >/proc/sys/kernel/sysrq -The number may be written either as decimal or as hexadecimal with the -0x prefix. +The number may be written here either as decimal or as hexadecimal +with the 0x prefix. CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE must always be +written in hexadecimal. Note that the value of /proc/sys/kernel/sysrq influences only the invocation via a keyboard. Invocation of any operation via /proc/sysrq-trigger is always |