X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=Documentation%2Foops-tracing.txt;h=6fe9001b92634ec306a745d5842883640db79597;hb=d294ed69408b54c18f0420516ea057b2a734624d;hp=66eaaab7773d551691181070daead961fca33df2;hpb=1cc5753f86589c5fb7e2f4a1fe778db3881f8f72;p=safe%2Fjmp%2Flinux-2.6

diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt
index 66eaaab..6fe9001 100644
--- a/Documentation/oops-tracing.txt
+++ b/Documentation/oops-tracing.txt
@@ -1,6 +1,6 @@
 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 fron 2.6 that
+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
@@ -30,17 +30,20 @@ the disk is not available then you have three options :-
 
 (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.
+(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
@@ -83,6 +86,20 @@ stuff are the values reported by the Oops - you can just cut-and-paste
 and do a replace of spaces to "\x" - that's what I do, as I'm too lazy 
 to write a program to automate this all).
 
+Alternatively, you can use the shell script in scripts/decodecode.
+Its usage is:  decodecode < oops.txt
+
+The hex bytes that follow "Code:" may (in some architectures) have a series
+of bytes that precede the current instruction pointer as well as bytes at and
+following the current instruction pointer.  In some cases, one instruction
+byte or word is surrounded by <> or (), as in "<86>" or "(f00d)".  These
+<> or () markings indicate the current instruction pointer.  Example from
+i386, split into multiple lines for readability:
+
+Code: f9 0f 8d f9 00 00 00 8d 42 0c e8 dd 26 11 c7 a1 60 ea 2b f9 8b 50 08 a1
+64 ea 2b f9 8d 34 82 8b 1e 85 db 74 6d 8b 15 60 ea 2b f9 <8b> 43 04 39 42 54
+7e 04 40 89 42 54 8b 43 04 3b 05 00 f6 52 c0
+
 Finally, if you want to see where the code comes from, you can do
 
 	cd /usr/src/linux
@@ -231,6 +248,21 @@ characters, each representing a particular tainted value.
   6: 'B' if a page-release function has found a bad page reference or
      some unexpected page flags.
 
+  7: 'U' if a user or user application specifically requested that the
+     Tainted flag be set, ' ' otherwise.
+
+  8: 'D' if the kernel has died recently, i.e. there was an OOPS or BUG.
+
+  9: 'A' if the ACPI table has been overridden.
+
+ 10: 'W' if a warning has previously been issued by the kernel.
+     (Though some warnings may set more specific taint flags.)
+
+ 11: 'C' if a staging driver has been loaded.
+
+ 12: 'I' if the kernel is working around a severe bug in the platform
+     firmware (BIOS or similar).
+
 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