SysRq debugger - Revision history

Sergey Bronnikov: Marked this version for translation

2015-12-26T08:37:07Z

Marked this version for translation

Sergey Bronnikov: add 'translate' tags

2015-12-25T22:47:28Z

add 'translate' tags

Kir: fixed formatting in /* Working with proc */

2006-10-27T10:28:48Z

fixed formatting in ‎Working with proc

Xemul at 13:35, 7 August 2006

2006-08-07T13:35:17Z

Xemul: created

2006-08-07T13:32:43Z

created

New page

''SysRq debugger'' can help you to obtain some information from oops-ed kernel.

== Features ==
''SysRq debugger'' can do one of the following:
# Dump memory at specified address
# Write arbitrary value to memory at specified address
# Resolve symbol address by its name

== How to use it ==
To enter debug mode press ''SysRq-g''.
After this the following commands will be available:
# ''SysRq-d'' - dump memory
# ''SysRq-w'' - write to memory
# ''SysRq-r'' - resolve symbol
# ''SysRq-x'' - go on dumping memory
#* ... from the latest address dumped with ''-d''
#* ... from the address you wrote to with ''-w''
#* ... from the begginning of the symbol resolved with ''-r''
# ''SysRq-q'' - quit debugger

After entering ''-d'', ''-w'' or ''-r'' state you must enter address to work with (and the value you want to write if you do). Simply do this by pressing according keys while holding ''Alt-StsRq''.

If you need to enter the upper case letter or the underbar (<code>_</code>) while typing a symbol name then you need to press and release ''shift'' and then the letter or minus (<code>-</code>).

At the end press ''enter''.

== Working with proc ==
There is a ''/proc/sysrq-trigger'' entry which triggers sysrq events.
You may send a string to it to trigger commands one by one.
There is one note about it - string must end with '\r' character.

== Examples ==
Here are some examples of how to use debugger

=== Dump memory ===
<pre>
# echo -n -e 'gd0xc0000000\rq' > /proc/sysrq-trigger
</pre>
will dump memory region of 512 bytes

<pre>
# echo -n -e 'gxq' > /proc/sysrq-trigger
</pre>
will dump the next 512 bytes of memory

=== Write to memory ===
<pre>
# echo -n -e 'gw0xc0000000-0x12345678\rq' > /proc/sysrq-trigger
</pre>
will write ''0x12345678'' at ''0xc0000000''

=== Resolve symbol ===
<pre>
# echo -n -e 'grschedule\rq' > /proc/sysrq-trigger
</pre>
will print you an address ''schedule()'' function starts from

<pre>
# echo -n -e 'gxq' > /proc/sysrq-trigger
</pre>
will dump first 512 bytes of it

Note ''-n'' and ''-e'' keys to ''echo'' command.

[[Category:HOWTO]]
[[Category:Kernel]]

@@ Line 1: / Line 1: @@
 ''SysRq debugger'' can help you to obtain some information from oops-ed kernel. This feature is available since 026test017 kernel.
@@ Line 62: / Line 63: @@
 Note <i>''-n''</i> and <i>''-e''</i> keys to ''echo'' command.
 [[Category:HOWTO]]
 [[Category:Kernel]]

@@ Line 26: / Line 26: @@
 == Working with proc ==
-There is a ''/proc/sysrq-trigger'' entry which triggers sysrq events.
+There is a <code>/proc/sysrq-trigger</code> entry which triggers sysrq events.
-You may send a string to it to trigger commands one by one.
+You may write a string to it to trigger commands one by one.
-There is one note about it - string must end with '<i>\r</i>' character.
+There is one note: the string must end with the <code>\r</code> character.
 == Examples ==

← Older revision		Revision as of 13:35, 7 August 2006
Line 1:		Line 1:
−	''SysRq debugger'' can help you to obtain some information from oops-ed kernel.	+	''SysRq debugger'' can help you to obtain some information from oops-ed kernel. This feature is available since 026test017 kernel.

	== Features ==		== Features ==

@@ Line 1: / Line 1: @@
 <translate>
 ''SysRq debugger'' can help you to obtain some information from oops-ed kernel. This feature is available since 026test017 kernel.
-== Features ==
+== Features == <!--T:2-->
 ''SysRq debugger'' can do one of the following:
 # Dump memory at specified address
@@ Line 8: / Line 9: @@
 # Resolve symbol address by its name
-== How to use it ==
+== How to use it == <!--T:3-->
 To enter debug mode press ''SysRq-g''.
 After this the following commands will be available:
@@ Line 20: / Line 21: @@
 # ''SysRq-q'' - quit debugger
 After entering ''-d'', ''-w'' or ''-r'' state you must enter address to work with (and the value you want to write if you do). Simply do this by pressing according keys while holding ''Alt-StsRq''.
 If you need to enter the upper case letter or the underbar (<code>_</code>) while typing a symbol name then you need to press and release ''shift'' and then the letter or minus (<code>-</code>).
 At the end press ''enter''.
-== Working with proc ==
+== Working with proc == <!--T:7-->
 There is a <code>/proc/sysrq-trigger</code> entry which triggers sysrq events.
 You may write a string to it to trigger commands one by one.
 There is one note: the string must end with the <code>\r</code> character.
-== Examples ==
+== Examples == <!--T:8-->
 Here are some examples of how to use debugger
-=== Dump memory ===
+=== Dump memory === <!--T:9-->
 <pre>
 # echo -n -e 'gd0xc0000000\rq' > /proc/sysrq-trigger
@@ Line 40: / Line 44: @@
 will dump memory region of 512 bytes
 <pre>
 # echo -n -e 'gxq' > /proc/sysrq-trigger
@@ Line 45: / Line 50: @@
 will dump the next 512 bytes of memory
-=== Write to memory ===
+=== Write to memory === <!--T:11-->
 <pre>
 # echo -n -e 'gw0xc0000000-0x12345678\rq' > /proc/sysrq-trigger
@@ Line 51: / Line 56: @@
 will write ''0x12345678'' at ''0xc0000000''
-=== Resolve symbol ===
+=== Resolve symbol === <!--T:12-->
 <pre>
 # echo -n -e 'grschedule\rq' > /proc/sysrq-trigger
@@ Line 57: / Line 62: @@
 will print you an address ''schedule()'' function starts from
 <pre>
 # echo -n -e 'gxq' > /proc/sysrq-trigger
@@ Line 62: / Line 68: @@
 will dump first 512 bytes of it
 Note <i>''-n''</i> and <i>''-e''</i> keys to ''echo'' command.
 </translate>