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| author | Carsten Emde <C.Emde@osadl.org> | 2011-07-19 13:51:17 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2014-10-31 10:54:40 -0400 |
| commit | f6c26e72a343fd682720f7020628645185923daf (patch) | |
| tree | 0556a587ca60ba76130ceeb6c34082a76bdab4e7 /Documentation/sysrq.txt | |
| parent | da9278d23ccb02f332eba710558b01e4b1ceac61 (diff) | |
| download | linux-rt-f6c26e72a343fd682720f7020628645185923daf.tar.gz | |
net: sysrq via icmp
There are (probably rare) situations when a system crashed and the system
console becomes unresponsive but the network icmp layer still is alive.
Wouldn't it be wonderful, if we then could submit a sysreq command via ping?
This patch provides this facility. Please consult the updated documentation
Documentation/sysrq.txt for details.
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Diffstat (limited to 'Documentation/sysrq.txt')
| -rw-r--r-- | Documentation/sysrq.txt | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt index 0e307c94809a..6964d0f80ae7 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt @@ -59,10 +59,17 @@ On PowerPC - Press 'ALT - Print Screen (or F13) - <command key>, On other - If you know of the key combos for other architectures, please let me know so I can add them to this section. -On all - write a character to /proc/sysrq-trigger. e.g.: - +On all - write a character to /proc/sysrq-trigger, e.g.: echo t > /proc/sysrq-trigger +On all - Enable network SysRq by writing a cookie to icmp_echo_sysrq, e.g. + echo 0x01020304 >/proc/sys/net/ipv4/icmp_echo_sysrq + Send an ICMP echo request with this pattern plus the particular + SysRq command key. Example: + # ping -c1 -s57 -p0102030468 + will trigger the SysRq-H (help) command. + + * What are the 'command' keys? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 'b' - Will immediately reboot the system without syncing or unmounting |