From e8b5cbb041130ef297c90f8af2d3d45dfb9e6d15 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 7 Oct 2013 00:48:46 +0100 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- Documentation/sysrq.txt | 19 +++++++++++-------- 1 file 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). -- cgit v1.2.3