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| author | Ben Hutchings <ben@decadent.org.uk> | 2013-10-07 00:48:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-16 13:01:44 -0700 |
| commit | e8b5cbb041130ef297c90f8af2d3d45dfb9e6d15 (patch) | |
| tree | efe6b006590c85da117c63f41a501ceb29f33297 /Documentation/sysrq.txt | |
| parent | 190c6cc32843844722a9897fac1929d57517db14 (diff) | |
| download | lwn-e8b5cbb041130ef297c90f8af2d3d45dfb9e6d15.tar.gz lwn-e8b5cbb041130ef297c90f8af2d3d45dfb9e6d15.zip | |
sysrq: Document hexadecimal values for kernel.sysrq bitmask
It makes more sense to enter a bitmask in hexadecimal rather than
decimal. Sadly we can't make it read back as hexadecimal.
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 | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt index 8cb4d7842a5f..1c0471dc70fe 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt @@ -20,18 +20,21 @@ in /proc/sys/kernel/sysrq: 1 - enable all functions of sysrq >1 - bitmask of allowed sysrq functions (see below for detailed function description): - 2 - enable control of console logging level - 4 - enable control of keyboard (SAK, unraw) - 8 - enable debugging dumps of processes etc. - 16 - enable sync command - 32 - enable remount read-only - 64 - enable signalling of processes (term, kill, oom-kill) - 128 - allow reboot/poweroff - 256 - allow nicing of all RT tasks + 2 = 0x2 - enable control of console logging level + 4 = 0x4 - enable control of keyboard (SAK, unraw) + 8 = 0x8 - enable debugging dumps of processes etc. + 16 = 0x10 - enable sync command + 32 = 0x20 - enable remount read-only + 64 = 0x40 - enable signalling of processes (term, kill, oom-kill) + 128 = 0x80 - allow reboot/poweroff + 256 = 0x100 - allow nicing of all RT tasks 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. + 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 allowed (by a user with admin privileges). |