linux-kernel - Re: [PATCH] scripts: improve the decodecode script

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Message-ID: <20081029172226.GD18050@hack.voiplan.pt>
Date:	Wed, 29 Oct 2008 17:22:26 +0000
From:	Américo Wang <xiyou.wangcong@...il.com>
To:	Arjan van de Ven <arjan@...radead.org>
Cc:	rdunlap@...otime.net, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] scripts: improve the decodecode script

On Wed, Oct 29, 2008 at 10:00:45AM -0700, Arjan van de Ven wrote:
>>From 80bf813c2bdc3538d823bb59c2611b40673e395a Mon Sep 17 00:00:00 2001
>From: Arjan van de Ven <arjan@...ux.intel.com>
>Date: Wed, 29 Oct 2008 09:57:07 -0700
>Subject: [PATCH] scripts: improve the decodecode script
>
>kerneloops.org has been using an improved "decodecode" script,
>specifically it has a special marker that shows which line
>in the assembly the oops happened at, like this:
>
>  20:	83 e0 03             	and    $0x3,%eax
>  23:	09 d8                	or     %ebx,%eax
>  25:	85 db                	test   %ebx,%ebx
>  27:	89 02                	mov    %eax,(%edx)
>  29:	74 0f                	je     0x3a
>  2b:*	3b 73 04             	cmp    0x4(%ebx),%esi     <-- trapping instruction
>  2e:	75 05                	jne    0x35
>  30:	89 53 04             	mov    %edx,0x4(%ebx)
>  33:	eb 07                	jmp    0x3c
>  35:	89 53 08             	mov    %edx,0x8(%ebx)
>
>this patch updates the kernel copy to also have this functionality.
>
>Signed-off-by: Arjan van de Ven <arjan@...ux.intel.com>
>---
> scripts/decodecode |   32 ++++++++++++++++++++++----------
> 1 files changed, 22 insertions(+), 10 deletions(-)
>
>diff --git a/scripts/decodecode b/scripts/decodecode
>index 235d393..dd9bf17 100755
>--- a/scripts/decodecode
>+++ b/scripts/decodecode
>@@ -7,7 +7,7 @@
> # AFLAGS=--32 decodecode < 386.oops
> 
> cleanup() {
>-	rm -f $T $T.s $T.o
>+	rm -f $T $T.s $T.o $T.oo $T.aa  $T.aaa
> 	exit 1
> }
> 
>@@ -44,21 +44,33 @@ if [ $marker -eq 0 ]; then
> 	marker=`expr index "$code" "\("`
> fi
> 
>+touch $T.oo
> if [ $marker -ne 0 ]; then
>-	beforemark=`echo "$code" | cut -c-$((${marker} - 1))`
>+	echo All code >> $T.oo
>+	echo ======== >> $T.oo
>+	beforemark=`echo "$code"`
> 	echo -n "	.byte 0x" > $T.s
>-	echo $beforemark | sed -e 's/ /,0x/g' >> $T.s
>-	as $AFLAGS -o $T.o $T.s
>-	objdump -S $T.o
>-	rm $T.o $T.s
>+	echo $beforemark | sed -e 's/ /,0x/g' | sed -e 's/<//g' | sed -e 's/>//g' >> $T.s
>+	as $AFLAGS -o $T.o $T.s &> /dev/null
>+	objdump -S $T.o | grep -v "/tmp" | grep -v "Disassembly" | grep -v "\.text" | grep -v "^$" &> $T.ooo
>+	cat $T.ooo >> $T.oo
>+	rm -f $T.o $T.s  $T.ooo
> 
> # and fix code at-and-after marker
> 	code=`echo "$code" | cut -c$((${marker} + 1))-`
> fi
>-
>+echo Code starting with the faulting instruction  > $T.aa
>+echo =========================================== >> $T.aa
> code=`echo $code | sed -e 's/ [<(]/ /;s/[>)] / /;s/ /,0x/g'`
> echo -n "	.byte 0x" > $T.s
> echo $code >> $T.s
>-as $AFLAGS -o $T.o $T.s
>-objdump -S $T.o
>-rm $T $T.s $T.o
>+as $AFLAGS -o $T.o $T.s &> /dev/null
>+objdump -S $T.o | grep -v "Disassembly" | grep -v "/tmp" | grep -v "\.text" | grep -v "^$" &> $T.aaa
>+cat $T.aaa >> $T.aa
>+
>+faultline=`cat $T.aaa | head -1 | cut -d":" -f2`
>+
>+cat $T.oo | sed -e "s/\($faultline\)/\*\1     <-- trapping instruction/g"
>+echo
>+cat $T.aa
>+rm -f $T.o $T.s $T $T.oo $T.aa  $T.aaa[5~

what is $T.aaa[5~ ?  :-)

And why not call cleanup() here?

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

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