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

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Date:	Fri, 31 Oct 2008 11:38:00 +0000
From:	Américo Wang <xiyou.wangcong@...il.com>
To:	Arjan van de Ven <arjan@...radead.org>
Cc:	Américo Wang <xiyou.wangcong@...il.com>,
	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 12:20:02PM -0700, Arjan van de Ven wrote:
>On Wed, 29 Oct 2008 17:22:26 +0000
>Américo Wang <xiyou.wangcong@...il.com> wrote:
>
>> 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?
>
>good point
>
>update below
>

Looks good, thanks!

If you need, add:

Reviewed-by: WANG Cong <wangcong@...ux.org>


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

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