[patch 6/8] scripts: improve the decodecode script

akpm
2008-12-01T22:22:00Z

From: Arjan van de Ven <arjan@linux.intel.com>

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@linux.intel.com>
Reviewed-by: WANG Cong <wangcong@zeuux.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

scripts/decodecode | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)

diff -puN scripts/decodecode~scripts-improve-the-decodecode-script scripts/decodecode
--- a/scripts/decodecode~scripts-improve-the-decodecode-script
+++ a/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
+cleanup
_