[PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Arjan van de Ven]

Hi,

I had this script lying around (used on kerneloops.org in a slightly modified form, 
where I use a database as input rather than stdin). I think it's a useful tool,
at least I find it extremely useful in turning oopses into an "oh duh yes there"
experience...

I know it's in perl, and I know I suck at writing good perl. So I welcome all feedback I
can get... both on the perl and on the usefulness of having this script.
 

>From 260d3f2246a4fe92f4ec633db82ab44605654d4f Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Wed, 5 Nov 2008 19:00:36 -0800
Subject: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

We're strugling all the time to figure out where the code came from
that oopsed.. The script below (a adaption from a script used by kerneloops.org)
can help developers quite a bit, at least for non-module cases.

It works and looks like this:

[/home/arjan/linux]$ dmesg | perl scripts/markup_code.pl vmlinux
 {
 	struct agp_memory *memory;

 	memory = agp_allocate_memory(agp_bridge, pg_count, type);
 c055c10f:	89 c2                	mov    %eax,%edx
 	if (memory == NULL)
 c055c111:	74 19                	je     c055c12c <agp_allocate_memory_wrap+0x30>
 /* This function must only be called when current_controller != NULL */
 static void agp_insert_into_pool(struct agp_memory * temp)
 {
 	struct agp_memory *prev;

 	prev = agp_fe.current_controller->pool;
 c055c113:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
*c055c118:	8b 40 10             	mov    0x10(%eax),%eax     <----- faulting instruction

 	if (prev != NULL) {
 c055c11b:	85 c0                	test   %eax,%eax
 c055c11d:	74 05                	je     c055c124 <agp_allocate_memory_wrap+0x28>
 		prev->prev = temp;
 c055c11f:	89 50 04             	mov    %edx,0x4(%eax)
 		temp->next = prev;
 c055c122:	89 02                	mov    %eax,(%edx)
 	}
 	agp_fe.current_controller->pool = temp;
 c055c124:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
 c055c129:	89 50 10             	mov    %edx,0x10(%eax)
 	if (memory == NULL)
 		return NULL;

 	agp_insert_into_pool(memory);

so in this case, we faulted while dereferencing agp_fe.current_controller pointer, and we get to see
exactly which function and line it affects... Personally I find this very useful, and I can
see value for having this script in the kernel for more-than-just-me to use.

Caveats:
* It only works for oopses not-in-modules
* It only works nicely for kernels compiled with CONFIG_DEBUG_INFO
* It's not very fast.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
 scripts/markup_oops.pl |  165 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 165 insertions(+), 0 deletions(-)
 create mode 100644 scripts/markup_oops.pl

diff --git a/scripts/markup_oops.pl b/scripts/markup_oops.pl
new file mode 100644
index 0000000..c8a2200
--- /dev/null
+++ b/scripts/markup_oops.pl
@@ -0,0 +1,165 @@
+#!/usr/bin/perl -w
+
+# Copyright 2008, Intel Corporation
+#
+# This file is part of the Linux kernel
+#
+# This program file is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; version 2 of the License.
+#
+# Authors:
+# 	Arjan van de Ven <arjan@linux.intel.com>
+
+
+my $vmlinux_name = $ARGV[0];
+
+#
+# Step 1: Parse the oops to find the EIP value
+# 
+
+my $target = "0";
+while (<STDIN>) {
+  if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
+      $target = $1;
+  }
+}
+
+if ($target =~ /^f8/) {
+  print "This script does not work on modules ... \n";
+  exit;
+}
+
+if ($target eq "0") {
+  print "No oops found!\n";
+  print "Usage: \n";
+  print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
+  exit;
+}
+
+my $counter = 0;
+my $state = 0;
+my $center = 0;
+my @lines;
+
+sub InRange {
+  my ($address, $target) = @_;
+  my $ad = "0x".$address;
+  my $ta = "0x".$target;
+  my $delta = hex($ad) - hex($ta);
+
+  if (($delta > -4096) && ($delta < 4096)) {
+    return 1;
+  }
+  return 0;
+}
+                            
+ 
+
+# first, parse the input into the lines array, but to keep size down,
+# we only do this for 4Kb around the sweet spot
+
+my $filename;
+
+open(FILE, "objdump -dS $vmlinux_name |") || die "Cannot start objdump";
+
+while (<FILE>) {
+  my $line = $_;
+  chomp($line);
+  if ($state == 0) {
+      if ($line =~ /^([a-f0-9]+)\:/) {
+          if (InRange($1, $target)) {
+              $state = 1;
+          }
+      }
+  } else {
+      if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) {
+          my $val = $1;
+          if (!InRange($val, $target)) {
+              last;
+          }
+          if ($val eq $target) {
+              $center = $counter;
+          }
+      }
+     $lines[$counter] = $line;
+     
+     $counter = $counter + 1;     
+  }
+}
+
+close(FILE);
+
+if ($counter == 0) {
+  print "No matching code found \n";
+  exit;
+}
+
+if ($center == 0) {
+  print "No matching code found \n";
+  exit;
+}
+
+my $start;
+my $finish;
+my $codelines;
+my $binarylines;
+# now we go up and down in the array to find how much we want to print
+
+$start = $center;
+$codelines = 0;
+$binarylines = 0;
+while ($start > 1) {
+  $start = $start - 1;
+  my $line = $lines[$start];
+  if ($line =~ /^([a-f0-9]+)\:/) {
+      $binarylines = $binarylines + 1;
+  } else {
+      $codelines = $codelines + 1;
+  }
+  if ($codelines > 10) {
+    last;
+  }
+  if ($binarylines > 20) {
+    last;
+  }
+}
+
+
+$finish = $center;
+$codelines = 0;
+$binarylines = 0;
+while ($finish < $counter) {
+  $finish = $finish + 1;
+  my $line = $lines[$finish];
+  if ($line =~ /^([a-f0-9]+)\:/) {
+      $binarylines = $binarylines + 1;
+  } else {
+      $codelines = $codelines + 1;
+  }
+  if ($codelines > 10) {
+    last;
+  }
+  if ($binarylines > 20) {
+    last;
+  }
+}
+
+
+my $i;
+
+my $fulltext = "";
+$i = $start;
+while ($i < $finish) {
+    if ($i == $center) {
+      $fulltext = $fulltext . "*$lines[$i]     <----- faulting instruction\n";
+    } else {
+      $fulltext = $fulltext .  " $lines[$i]\n";
+    }
+    $i = $i +1;
+}
+
+
+
+print $fulltext;
+
-- 
1.6.0.3



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Keith Owens]

Arjan van de Ven (on Wed, 5 Nov 2008 19:07:26 -0800) wrote:
>I had this script lying around (used on kerneloops.org in a slightly modified form, 
>where I use a database as input rather than stdin). I think it's a useful tool,
>at least I find it extremely useful in turning oopses into an "oh duh yes there"
>experience...
>
>Caveats:
>* It only works for oopses not-in-modules
>* It only works nicely for kernels compiled with CONFIG_DEBUG_INFO
>* It's not very fast.

Another caveat: "if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/)" means that
it only works on x86_32.

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Arjan van de Ven]

On Thu, 06 Nov 2008 15:15:22 +1100
Keith Owens <kaos@ocs.com.au> wrote:

> Arjan van de Ven (on Wed, 5 Nov 2008 19:07:26 -0800) wrote:
> >I had this script lying around (used on kerneloops.org in a slightly
> >modified form, where I use a database as input rather than stdin). I
> >think it's a useful tool, at least I find it extremely useful in
> >turning oopses into an "oh duh yes there" experience...
> >
> >Caveats:
> >* It only works for oopses not-in-modules
> >* It only works nicely for kernels compiled with CONFIG_DEBUG_INFO
> >* It's not very fast.
> 
> Another caveat: "if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/)" means
> that it only works on x86_32.
> 

true. I've not tried it/adapted it on any other arch yet.


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Américo Wang]

On Wed, Nov 05, 2008 at 07:07:26PM -0800, Arjan van de Ven wrote:
>Hi,
>

Hi,

thanks for your work!

>
>diff --git a/scripts/markup_oops.pl b/scripts/markup_oops.pl
>new file mode 100644
>index 0000000..c8a2200
>--- /dev/null
>+++ b/scripts/markup_oops.pl
>@@ -0,0 +1,165 @@
>+#!/usr/bin/perl -w
>+
>+# Copyright 2008, Intel Corporation
>+#
>+# This file is part of the Linux kernel
>+#
>+# This program file is free software; you can redistribute it and/or modify it
>+# under the terms of the GNU General Public License as published by the
>+# Free Software Foundation; version 2 of the License.
>+#
>+# Authors:
>+# 	Arjan van de Ven <arjan@linux.intel.com>
>+
>+
>+my $vmlinux_name = $ARGV[0];
>+
>+#
>+# Step 1: Parse the oops to find the EIP value
>+# 
>+
>+my $target = "0";
>+while (<STDIN>) {
>+  if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
>+      $target = $1;
>+  }
>+}
>+
>+if ($target =~ /^f8/) {
>+  print "This script does not work on modules ... \n";
>+  exit;
>+}
>+
>+if ($target eq "0") {
>+  print "No oops found!\n";
>+  print "Usage: \n";
>+  print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
>+  exit;


One thing to note here, no oops doesn't always mean wrong usage. :)
So I think usage should be printed only when the usage is actually
wrong, e.g. ARGV[0] is missed.



>+$start = $center;
>+$codelines = 0;
>+$binarylines = 0;

Why not fold these lines into their definitions?


-- 
"Sometimes the only way to stay sane is to go a little crazy."

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Arjan van de Ven]

On Wed, 26 Nov 2008 09:18:46 +0100
"Vegard Nossum" <vegard.nossum@gmail.com> wrote:

> On Sun, Nov 23, 2008 at 10:00 PM, Arjan van de Ven
> <arjan@infradead.org> wrote:
> > From 57b0deb1ad706a94e3118baee4127676f465c4ab Mon Sep 17 00:00:00
> > 2001 From: Arjan van de Ven <arjan@linux.intel.com>
> > Date: Wed, 5 Nov 2008 19:00:36 -0800
> > Subject: [PATCH] scripts: script from kerneloops.org to pretty
> > print oops dumps
> >
> > We're strugling all the time to figure out where the code came from
> > that oopsed.. The script below (a adaption from a script used by
> > kerneloops.org) can help developers quite a bit, at least for
> > non-module cases.
> 
> Hi,
> 
> Just small style nitpicks below :-) (You pick which ones to heed.)

Hi,

I'm sure your nitpicks make the perl script more perl like, and are
good suggestions from that view.
However, I'm not a perl hacker, and neither are most other kernel
hackers, and to be honest, for me, the more a perl script looks like
"bash with regexps" the better, because I can actually read, understand
and debug it in that case ;-)

Greetings,
    Arjan van de Ven

-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Andi Kleen]

Andrew Morton <akpm@linux-foundation.org> writes:

> On Wed, 26 Nov 2008 08:24:45 +0100 Ingo Molnar <mingo@elte.hu> wrote:
>
>> >  scripts/markup_oops.pl |  162 ++++++++++++++++++++++++++++++++++++++++++++++++
>> >  1 files changed, 162 insertions(+), 0 deletions(-)
>> >  create mode 100644 scripts/markup_oops.pl
>> 
>> looks useful - Andrew, Sam, any objections to this?
>
> who-me-no-i-already-merged-it.
>
> I didn't test it though - I don't have particularly high hopes given
> the general deadness of `make mm/memory.lst' for the past numerous
> years.

make mm/memory.lst should work again with latest binutils. The problem
earlier was that objdump -S was incompatible with unit-at-a-time
mode in gcc, but I fixed that and the binutils maintainers included
the patch.

-Andi

-- 
ak@linux.intel.com

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Ingo Molnar]

* Andrew Morton <akpm@linux-foundation.org> wrote:

> On Wed, 26 Nov 2008 08:24:45 +0100 Ingo Molnar <mingo@elte.hu> wrote:
> 
> > >  scripts/markup_oops.pl |  162 ++++++++++++++++++++++++++++++++++++++++++++++++
> > >  1 files changed, 162 insertions(+), 0 deletions(-)
> > >  create mode 100644 scripts/markup_oops.pl
> > 
> > looks useful - Andrew, Sam, any objections to this?
> 
> who-me-no-i-already-merged-it.
> 
> I didn't test it though - I don't have particularly high hopes given 
> the general deadness of `make mm/memory.lst' for the past numerous 
> years.
> 
> But it's worth trying.  The challenge will be getting people to 
> remember that it exists, and to use it.
> 
> I often turn off CONFIG_DEUG_INFO because it slows builds down so 
> much. It is irritating when such a kernel goes splat.

i keep DEBUG_INFO turned off all the time, and only turn it on if 
really needed. But in that case i can just turn it on and rebuild: 
recent gccs seem better at keeping the image unmodified. (or at least 
so i kid myself)

Years ago the image would mute a bit with DEBUG_INFO enabled, making 
the splat info fuzzy. Seems better now.

	Ingo

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Vegard Nossum]

On Sun, Nov 23, 2008 at 10:00 PM, Arjan van de Ven <arjan@infradead.org> wrote:
> From 57b0deb1ad706a94e3118baee4127676f465c4ab Mon Sep 17 00:00:00 2001
> From: Arjan van de Ven <arjan@linux.intel.com>
> Date: Wed, 5 Nov 2008 19:00:36 -0800
> Subject: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps
>
> We're strugling all the time to figure out where the code came from
> that oopsed.. The script below (a adaption from a script used by kerneloops.org)
> can help developers quite a bit, at least for non-module cases.

Hi,

Just small style nitpicks below :-) (You pick which ones to heed.)


> ---
>  scripts/markup_oops.pl |  162 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 162 insertions(+), 0 deletions(-)
>  create mode 100644 scripts/markup_oops.pl
>
> diff --git a/scripts/markup_oops.pl b/scripts/markup_oops.pl
> new file mode 100644
> index 0000000..700a7a6
> --- /dev/null
> +++ b/scripts/markup_oops.pl
> @@ -0,0 +1,162 @@
> +#!/usr/bin/perl -w
> +
> +# Copyright 2008, Intel Corporation
> +#
> +# This file is part of the Linux kernel
> +#
> +# This program file is free software; you can redistribute it and/or modify it
> +# under the terms of the GNU General Public License as published by the
> +# Free Software Foundation; version 2 of the License.
> +#
> +# Authors:
> +#      Arjan van de Ven <arjan@linux.intel.com>

use strict;
use warnings;

:-)

> +
> +
> +my $vmlinux_name = $ARGV[0];

I think the idiomatic way would be:

my $vmlinux_name = shift || 'vmlinux';

> +
> +#
> +# Step 1: Parse the oops to find the EIP value
> +#
> +
> +my $target = "0";
> +while (<STDIN>) {
> +       if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {

if (m/EIP:.../) {

is more elegant :-)

> +               $target = $1;
> +       }
> +}
> +
> +if ($target =~ /^f8/) {
> +       print "This script does not work on modules ... \n";
> +       exit;
> +}
> +
> +if ($target eq "0") {
> +       print "No oops found!\n";
> +       print "Usage: \n";
> +       print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
> +       exit;
> +}
> +
> +my $counter = 0;
> +my $state   = 0;
> +my $center  = 0;
> +my @lines;
> +
> +sub InRange {
> +       my ($address, $target) = @_;
> +       my $ad = "0x".$address;
> +       my $ta = "0x".$target;
> +       my $delta = hex($ad) - hex($ta);
> +
> +       if (($delta > -4096) && ($delta < 4096)) {
> +               return 1;
> +       }
> +       return 0;

or just return ($delta > -4096) && ($delta < 4096);

> +}
> +
> +
> +
> +# first, parse the input into the lines array, but to keep size down,
> +# we only do this for 4Kb around the sweet spot
> +
> +my $filename;
> +
> +open(FILE, "objdump -dS $vmlinux_name |") || die "Cannot start objdump";

use open(my $fd, ...); for running with strict, and replace FILE with
$fd everywhere else

> +
> +while (<FILE>) {
> +       my $line = $_;

Then you might as well do:

for my $line (<FILE>) {

> +       chomp($line);
> +       if ($state == 0) {
> +               if ($line =~ /^([a-f0-9]+)\:/) {
> +                       if (InRange($1, $target)) {
> +                               $state = 1;
> +                       }
> +               }
> +       } else {
> +               if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) {
> +                       my $val = $1;
> +                       if (!InRange($val, $target)) {
> +                               last;
> +                       }

last unless InRange($val, $target);

> +                       if ($val eq $target) {
> +                               $center = $counter;
> +                       }

$center = $counter if $val eq $target;

> +               }
> +               $lines[$counter] = $line;
> +
> +               $counter = $counter + 1;
> +       }
> +}
> +
> +close(FILE);
> +
> +if ($counter == 0) {
> +       print "No matching code found \n";

Trailing space?

> +       exit;
> +}
> +
> +if ($center == 0) {
> +       print "No matching code found \n";

Also here.

> +       exit;
> +}
> +
> +my $start;
> +my $finish;
> +my $codelines = 0;
> +my $binarylines = 0;
> +# now we go up and down in the array to find how much we want to print
> +
> +$start = $center;
> +
> +while ($start > 1) {
> +       $start = $start - 1;
> +       my $line = $lines[$start];
> +       if ($line =~ /^([a-f0-9]+)\:/) {
> +               $binarylines = $binarylines + 1;
> +       } else {
> +               $codelines = $codelines + 1;
> +       }
> +       if ($codelines > 10) {
> +               last;
> +       }
> +       if ($binarylines > 20) {
> +               last;
> +       }

last if $codelines > 10 || $binarylines > 20;

> +}
> +
> +
> +$finish = $center;
> +$codelines = 0;
> +$binarylines = 0;
> +while ($finish < $counter) {
> +       $finish = $finish + 1;
> +       my $line = $lines[$finish];
> +       if ($line =~ /^([a-f0-9]+)\:/) {
> +               $binarylines = $binarylines + 1;
> +       } else {
> +               $codelines = $codelines + 1;
> +       }
> +       if ($codelines > 10) {
> +               last;
> +       }
> +       if ($binarylines > 20) {
> +               last;
> +       }

last if $codelines > 10 || $binarylines > 20;

> +}
> +
> +
> +my $i;
> +
> +my $fulltext = "";
> +$i = $start;
> +while ($i < $finish) {
> +       if ($i == $center) {
> +               $fulltext = $fulltext . "*$lines[$i]     <----- faulting instruction\n";
> +       } else {
> +               $fulltext = $fulltext .  " $lines[$i]\n";
> +       }
> +       $i = $i +1;
> +}
> +
> +print $fulltext;
> +
> --


Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Andrew Morton]

On Wed, 26 Nov 2008 08:24:45 +0100 Ingo Molnar <mingo@elte.hu> wrote:

> >  scripts/markup_oops.pl |  162 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 162 insertions(+), 0 deletions(-)
> >  create mode 100644 scripts/markup_oops.pl
> 
> looks useful - Andrew, Sam, any objections to this?

who-me-no-i-already-merged-it.

I didn't test it though - I don't have particularly high hopes given
the general deadness of `make mm/memory.lst' for the past numerous
years.

But it's worth trying.  The challenge will be getting people to
remember that it exists, and to use it.

I often turn off CONFIG_DEUG_INFO because it slows builds down so much.
It is irritating when such a kernel goes splat.

Re: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Ingo Molnar]

* Arjan van de Ven <arjan@infradead.org> wrote:

> From 57b0deb1ad706a94e3118baee4127676f465c4ab Mon Sep 17 00:00:00 2001
> From: Arjan van de Ven <arjan@linux.intel.com>
> Date: Wed, 5 Nov 2008 19:00:36 -0800
> Subject: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps
> 
> We're strugling all the time to figure out where the code came from
> that oopsed.. The script below (a adaption from a script used by kerneloops.org)
> can help developers quite a bit, at least for non-module cases.
> 
> It works and looks like this:
> 
> [/home/arjan/linux]$ dmesg | perl scripts/markup_oops.pl vmlinux
>  {
>  	struct agp_memory *memory;
> 
>  	memory = agp_allocate_memory(agp_bridge, pg_count, type);
>  c055c10f:	89 c2                	mov    %eax,%edx
>  	if (memory == NULL)
>  c055c111:	74 19                	je     c055c12c <agp_allocate_memory_wrap+0x30>
>  /* This function must only be called when current_controller != NULL */
>  static void agp_insert_into_pool(struct agp_memory * temp)
>  {
>  	struct agp_memory *prev;
> 
>  	prev = agp_fe.current_controller->pool;
>  c055c113:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
> *c055c118:	8b 40 10             	mov    0x10(%eax),%eax     <----- faulting instruction
> 
>  	if (prev != NULL) {
>  c055c11b:	85 c0                	test   %eax,%eax
>  c055c11d:	74 05                	je     c055c124 <agp_allocate_memory_wrap+0x28>
>  		prev->prev = temp;
>  c055c11f:	89 50 04             	mov    %edx,0x4(%eax)
>  		temp->next = prev;
>  c055c122:	89 02                	mov    %eax,(%edx)
>  	}
>  	agp_fe.current_controller->pool = temp;
>  c055c124:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
>  c055c129:	89 50 10             	mov    %edx,0x10(%eax)
>  	if (memory == NULL)
>  		return NULL;
> 
>  	agp_insert_into_pool(memory);
> 
> so in this case, we faulted while dereferencing agp_fe.current_controller pointer, and we get to see
> exactly which function and line it affects... Personally I find this very useful, and I can
> see value for having this script in the kernel for more-than-just-me to use.
> 
> Caveats:
> * It only works for oopses not-in-modules
> * It only works nicely for kernels compiled with CONFIG_DEBUG_INFO
> * It's not very fast.
> * It only works on x86
> 
> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
> ---
>  scripts/markup_oops.pl |  162 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 162 insertions(+), 0 deletions(-)
>  create mode 100644 scripts/markup_oops.pl

looks useful - Andrew, Sam, any objections to this?

	Ingo

[PATCH] scripts: script from kerneloops.org to pretty print oops dumps

[Arjan van de Ven]

>From 57b0deb1ad706a94e3118baee4127676f465c4ab Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Wed, 5 Nov 2008 19:00:36 -0800
Subject: [PATCH] scripts: script from kerneloops.org to pretty print oops dumps

We're strugling all the time to figure out where the code came from
that oopsed.. The script below (a adaption from a script used by kerneloops.org)
can help developers quite a bit, at least for non-module cases.

It works and looks like this:

[/home/arjan/linux]$ dmesg | perl scripts/markup_oops.pl vmlinux
 {
 	struct agp_memory *memory;

 	memory = agp_allocate_memory(agp_bridge, pg_count, type);
 c055c10f:	89 c2                	mov    %eax,%edx
 	if (memory == NULL)
 c055c111:	74 19                	je     c055c12c <agp_allocate_memory_wrap+0x30>
 /* This function must only be called when current_controller != NULL */
 static void agp_insert_into_pool(struct agp_memory * temp)
 {
 	struct agp_memory *prev;

 	prev = agp_fe.current_controller->pool;
 c055c113:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
*c055c118:	8b 40 10             	mov    0x10(%eax),%eax     <----- faulting instruction

 	if (prev != NULL) {
 c055c11b:	85 c0                	test   %eax,%eax
 c055c11d:	74 05                	je     c055c124 <agp_allocate_memory_wrap+0x28>
 		prev->prev = temp;
 c055c11f:	89 50 04             	mov    %edx,0x4(%eax)
 		temp->next = prev;
 c055c122:	89 02                	mov    %eax,(%edx)
 	}
 	agp_fe.current_controller->pool = temp;
 c055c124:	a1 ec dc 8f c0       	mov    0xc08fdcec,%eax
 c055c129:	89 50 10             	mov    %edx,0x10(%eax)
 	if (memory == NULL)
 		return NULL;

 	agp_insert_into_pool(memory);

so in this case, we faulted while dereferencing agp_fe.current_controller pointer, and we get to see
exactly which function and line it affects... Personally I find this very useful, and I can
see value for having this script in the kernel for more-than-just-me to use.

Caveats:
* It only works for oopses not-in-modules
* It only works nicely for kernels compiled with CONFIG_DEBUG_INFO
* It's not very fast.
* It only works on x86

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
---
 scripts/markup_oops.pl |  162 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 162 insertions(+), 0 deletions(-)
 create mode 100644 scripts/markup_oops.pl

diff --git a/scripts/markup_oops.pl b/scripts/markup_oops.pl
new file mode 100644
index 0000000..700a7a6
--- /dev/null
+++ b/scripts/markup_oops.pl
@@ -0,0 +1,162 @@
+#!/usr/bin/perl -w
+
+# Copyright 2008, Intel Corporation
+#
+# This file is part of the Linux kernel
+#
+# This program file is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; version 2 of the License.
+#
+# Authors:
+# 	Arjan van de Ven <arjan@linux.intel.com>
+
+
+my $vmlinux_name = $ARGV[0];
+
+#
+# Step 1: Parse the oops to find the EIP value
+#
+
+my $target = "0";
+while (<STDIN>) {
+	if ($_ =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
+		$target = $1;
+	}
+}
+
+if ($target =~ /^f8/) {
+	print "This script does not work on modules ... \n";
+	exit;
+}
+
+if ($target eq "0") {
+	print "No oops found!\n";
+	print "Usage: \n";
+	print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
+	exit;
+}
+
+my $counter = 0;
+my $state   = 0;
+my $center  = 0;
+my @lines;
+
+sub InRange {
+	my ($address, $target) = @_;
+	my $ad = "0x".$address;
+	my $ta = "0x".$target;
+	my $delta = hex($ad) - hex($ta);
+
+	if (($delta > -4096) && ($delta < 4096)) {
+		return 1;
+	}
+	return 0;
+}
+
+
+
+# first, parse the input into the lines array, but to keep size down,
+# we only do this for 4Kb around the sweet spot
+
+my $filename;
+
+open(FILE, "objdump -dS $vmlinux_name |") || die "Cannot start objdump";
+
+while (<FILE>) {
+	my $line = $_;
+	chomp($line);
+	if ($state == 0) {
+		if ($line =~ /^([a-f0-9]+)\:/) {
+			if (InRange($1, $target)) {
+				$state = 1;
+			}
+		}
+	} else {
+		if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) {
+			my $val = $1;
+			if (!InRange($val, $target)) {
+				last;
+			}
+			if ($val eq $target) {
+				$center = $counter;
+			}
+		}
+		$lines[$counter] = $line;
+
+		$counter = $counter + 1;
+	}
+}
+
+close(FILE);
+
+if ($counter == 0) {
+	print "No matching code found \n";
+	exit;
+}
+
+if ($center == 0) {
+	print "No matching code found \n";
+	exit;
+}
+
+my $start;
+my $finish;
+my $codelines = 0;
+my $binarylines = 0;
+# now we go up and down in the array to find how much we want to print
+
+$start = $center;
+
+while ($start > 1) {
+	$start = $start - 1;
+	my $line = $lines[$start];
+	if ($line =~ /^([a-f0-9]+)\:/) {
+		$binarylines = $binarylines + 1;
+	} else {
+		$codelines = $codelines + 1;
+	}
+	if ($codelines > 10) {
+		last;
+	}
+	if ($binarylines > 20) {
+		last;
+	}
+}
+
+
+$finish = $center;
+$codelines = 0;
+$binarylines = 0;
+while ($finish < $counter) {
+	$finish = $finish + 1;
+	my $line = $lines[$finish];
+	if ($line =~ /^([a-f0-9]+)\:/) {
+		$binarylines = $binarylines + 1;
+	} else {
+		$codelines = $codelines + 1;
+	}
+	if ($codelines > 10) {
+		last;
+	}
+	if ($binarylines > 20) {
+		last;
+	}
+}
+
+
+my $i;
+
+my $fulltext = "";
+$i = $start;
+while ($i < $finish) {
+	if ($i == $center) {
+		$fulltext = $fulltext . "*$lines[$i]     <----- faulting instruction\n";
+	} else {
+		$fulltext = $fulltext .  " $lines[$i]\n";
+	}
+	$i = $i +1;
+}
+
+print $fulltext;
+
-- 
1.6.0.3



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
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