> You should read the documentation!
> /usr/src/linux/Documentation/sysrq.txt says:
>
> * How do I enable the magic SysRQ key?
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> You need to say "yes" to 'Magic SysRq key (CONFIG_MAGIC_SYSRQ)' when
> configuring the kernel. This option is only available in 2.1.x or later
> kernels. Once you boot the new kernel, you need to enable it manually
> using following command:
>
> echo "1" > /proc/sys/kernel/sysrq
The documentation is wrong, I have submitted a patch twice for it.
The patch is attached again.
-d
--- sysrq.txt.old Mon Apr 10 23:09:01 2000
+++ sysrq.txt Thu Apr 20 23:52:50 2000
@@ -1,7 +1,7 @@
- MAGIC SYSRQ KEY DOCUMENTATION v1.32
+ MAGIC SYSRQ KEY DOCUMENTATION v1.33
------------------------------------
- [Sat Apr 8 22:15:03 CEST 2000]
+ [Fri Apr 20 23:48:03 PST 2000]
* What is the magic SysRQ key?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -12,10 +12,15 @@
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You need to say "yes" to 'Magic SysRq key (CONFIG_MAGIC_SYSRQ)' when
configuring the kernel. This option is only available in 2.1.x or later
-kernels. Once you boot the new kernel, you need to enable it manually
-using following command:
+kernels. Once you boot the new kernel it is enabled by default. You need to
+disable it manually using following command if you do not want sysrq
+functionality:
+
+To disable:
+ echo "0" > /proc/sys/kernel/sysrq
- echo "1" > /proc/sys/kernel/sysrq
+To enable:
+ echo "1" > /proc/sys/kernel/sysrq
* How do I use the magic SysRQ key?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -71,15 +76,20 @@
Well, un'R'aw is very handy when your X server or a svgalib program crashes.
sa'K' (Secure Access Key) is usefull when you want to be sure there are no
-trojan program is running at console and which could grab your password
-when you would try to login. It will kill all programs on given console
-and thus letting you make sure that the login prompt you see is actually
-the one from init, not some trojan program.
-IMPORTANT:In its true form it is not a true SAK like the one in :IMPORTANT
-IMPORTATN:c2 compliant systems, and it should be mistook as such. :IMPORTANT
- It seems other find it usefull as (System Attention Key) which is
-useful when you want to exit a program that will not let you switch consoles.
-(For example, X or a svgalib program.)
+trojan programs running on your console which could grab your password when
+you would try to login. It will kill all programs on your given console and
+thus letting you make sure that the login prompt you see is actually the one
+from init, not some trojan program.
+
+IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT
+ In its true form it is not a true SAK like the one in c2 compliant systems,
+ and it should be mistaken as such nor does it ensure a security from a
+ kernel module trojan intercepting an init child.
+IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT
+
+ It seems others find it useful as (System Attention Key) which is useful
+when you want to exit a program that will not let you switch consoles. (For
+example, X or a svgalib program.)
re'B'oot is good when you're unable to shut down. But you should also 'S'ync
and 'U'mount first.
@@ -124,10 +134,11 @@
* I have more questions, who can I ask?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You may feel free to send email to myrdraal@deathsdoor.com, and I will
-respond as soon as possible.
+respond as soon as possible.
-Myrdraal
* Credits
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Written by Mydraal <myrdraal@deathsdoor.com>
Updated by Adam Sulmicki <adam@cfar.umd.edu>
+Updated by David Ford <david@kalifornia.com>
-
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