Re: [PATCH] scripts: improve the decodecode script

From: AmÃrico Wang
Date: Wed Oct 29 2008 - 13:23:02 EST


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?

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

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