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| author | Carsten Emde <C.Emde@osadl.org> | 2011-07-19 12:51:17 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2013-04-04 22:09:31 (GMT) |
| commit | 738dc294e30e50c521e24867b18e67344b840b73 (patch) | |
| tree | 8d12f5db9c9a1285babbb5b56611dbfcb6a80438 /Documentation | |
| parent | ae5a202857700dc5f731646883e01f8123fa6505 (diff) | |
| download | linux-fsl-qoriq-738dc294e30e50c521e24867b18e67344b840b73.tar.xz | |
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')
| -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 2a4cdda..67ac78c 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt @@ -57,10 +57,17 @@ 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 |