+NOTE: ksymoops is useless on 2.6. Please use the Oops in its original format
+(from dmesg, etc). Ignore any references in this or other docs to "decoding
+the Oops" or "running it through ksymoops". If you post an Oops from 2.6 that
+has been run through ksymoops, people will just tell you to repost it.
+
Quick Summary
-------------
-Install ksymoops from
-ftp://ftp.<country>.kernel.org/pub/linux/utils/kernel/ksymoops
-Read the ksymoops man page.
-ksymoops < the_oops.txt
-
-and send the output the maintainer of the kernel area that seems to be
-involved with the problem, not to the ksymoops maintainer. Don't worry
-too much about getting the wrong person. If you are unsure send it to
-the person responsible for the code relevant to what you were doing.
-If it occurs repeatably try and describe how to recreate it. Thats
-worth even more than the oops
+Find the Oops and send it to the maintainer of the kernel area that seems to be
+involved with the problem. Don't worry too much about getting the wrong person.
+If you are unsure send it to the person responsible for the code relevant to
+what you were doing. If it occurs repeatably try and describe how to recreate
+it. That's worth even more than the oops.
If you are totally stumped as to whom to send the report, send it to
linux-kernel@vger.kernel.org. Thanks for your help in making Linux as
stable as humanly possible.
-Where is the_oops.txt?
+Where is the Oops?
----------------------
Normally the Oops text is read from the kernel buffers by klogd and
(1) Hand copy the text from the screen and type it in after the machine
has restarted. Messy but it is the only option if you have not
- planned for a crash.
+ planned for a crash. Alternatively, you can take a picture of
+ the screen with a digital camera - not nice, but better than
+ nothing. If the messages scroll off the top of the console, you
+ may find that booting with a higher resolution (eg, vga=791)
+ will allow you to read more of the text. (Caveat: This needs vesafb,
+ so won't help for 'early' oopses)
(2) Boot with a serial console (see Documentation/serial-console.txt),
run a null modem to a second machine and capture the output there
using your favourite communication program. Minicom works well.
-(3) Patch the kernel with one of the crash dump patches. These save
- data to a floppy disk or video rom or a swap partition. None of
- these are standard kernel patches so you have to find and apply
- them yourself. Search kernel archives for kmsgdump, lkcd and
- oops+smram.
-
-No matter how you capture the log output, feed the resulting file to
-ksymoops along with /proc/ksyms and /proc/modules that applied at the
-time of the crash. /var/log/ksymoops can be useful to capture the
-latter, man ksymoops for details.
+(3) Use Kdump (see Documentation/kdump/kdump.txt),
+ extract the kernel ring buffer from old memory with using dmesg
+ gdbmacro in Documentation/kdump/gdbmacros.txt.
Full Information
----------------
+NOTE: the message from Linus below applies to 2.4 kernel. I have preserved it
+for historical reasons, and because some of the information in it still
+applies. Especially, please ignore any references to ksymoops.
+
From: Linus Torvalds <torvalds@osdl.org>
How to track down an Oops.. [originally a mail to linux-kernel]
Tainted kernels:
Some oops reports contain the string 'Tainted: ' after the program
-counter, this indicates that the kernel has been tainted by some
-mechanism. The string is followed by a series of position sensitive
+counter. This indicates that the kernel has been tainted by some
+mechanism. The string is followed by a series of position-sensitive
characters, each representing a particular tainted value.
1: 'G' if all modules loaded have a GPL or compatible license, 'P' if
MODULE_LICENSE or with a MODULE_LICENSE that is not recognised by
insmod as GPL compatible are assumed to be proprietary.
- 2: 'F' if any module was force loaded by insmod -f, ' ' if all
+ 2: 'F' if any module was force loaded by "insmod -f", ' ' if all
modules were loaded normally.
3: 'S' if the oops occurred on an SMP kernel running on hardware that
- hasn't been certified as safe to run multiprocessor.
- Currently this occurs only on various Athlons that are not
- SMP capable.
+ hasn't been certified as safe to run multiprocessor.
+ Currently this occurs only on various Athlons that are not
+ SMP capable.
+
+ 4: 'R' if a module was force unloaded by "rmmod -f", ' ' if all
+ modules were unloaded normally.
+
+ 5: 'M' if any processor has reported a Machine Check Exception,
+ ' ' if no Machine Check Exceptions have occurred.
+
+ 6: 'B' if a page-release function has found a bad page reference or
+ some unexpected page flags.
The primary reason for the 'Tainted: ' string is to tell kernel
debuggers if this is a clean kernel or if anything unusual has
-occurred. Tainting is permanent, even if an offending module is
-unloading the tainted value remains to indicate that the kernel is not
+occurred. Tainting is permanent: even if an offending module is
+unloaded, the tainted value remains to indicate that the kernel is not
trustworthy.
git://git.onelab.eu / linux-2.6.git / blobdiff