Re: [PATCH] scripts: improve the decodecode script

[Arjan van de Ven]

On Wed, 29 Oct 2008 17:22:26 +0000
AmÃrico Wang <xiyou.wangcong@xxxxxxxxx> 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@xxxxxxxxxxxxxxx>
> >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@xxxxxxxxxxxxxxx>
> >---
> > 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