| Message ID | 1289917997-27429-1-git-send-email-avi@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 11/16/2010 08:33 AM, Avi Kivity wrote: > signrom.sh has multiple bugs: > > - the last byte is considered when calculating the existing checksum, but not > when computing the correction > - apprently the 'expr' expression overflows and produces incorrect results with > larger roms > - if the checksum happened to be zero, we calculated the correction byte to be > 256 > > Instead of rewriting this in half a line of python, this patch fixes the bugs. > > Signed-off-by: Avi Kivity<avi@redhat.com> > Applied. Thanks. Regards, Anthony Liguori > --- > pc-bios/optionrom/signrom.sh | 7 +++---- > 1 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/pc-bios/optionrom/signrom.sh b/pc-bios/optionrom/signrom.sh > index 975b27d..9dc5c63 100755 > --- a/pc-bios/optionrom/signrom.sh > +++ b/pc-bios/optionrom/signrom.sh > @@ -31,14 +31,13 @@ x=`dd if="$1" bs=1 count=1 skip=2 2>/dev/null | od -t u1 -A n` > size=$(( $x * 512 - 1 )) > > # now get the checksum > -nums=`od -A n -t u1 -v "$1"` > +nums=`od -A n -t u1 -v -N $size "$1"` > for i in ${nums}; do > # add each byte's value to sum > - sum=`expr $sum + $i` > + sum=`expr \( $sum + $i \) % 256` > done > > -sum=$(( $sum % 256 )) > -sum=$(( 256 - $sum )) > +sum=$(( (256 - $sum) % 256 )) > sum_octal=$( printf "%o" $sum ) > > # and write the output file >
diff --git a/pc-bios/optionrom/signrom.sh b/pc-bios/optionrom/signrom.sh index 975b27d..9dc5c63 100755 --- a/pc-bios/optionrom/signrom.sh +++ b/pc-bios/optionrom/signrom.sh @@ -31,14 +31,13 @@ x=`dd if="$1" bs=1 count=1 skip=2 2>/dev/null | od -t u1 -A n` size=$(( $x * 512 - 1 )) # now get the checksum -nums=`od -A n -t u1 -v "$1"` +nums=`od -A n -t u1 -v -N $size "$1"` for i in ${nums}; do # add each byte's value to sum - sum=`expr $sum + $i` + sum=`expr \( $sum + $i \) % 256` done -sum=$(( $sum % 256 )) -sum=$(( 256 - $sum )) +sum=$(( (256 - $sum) % 256 )) sum_octal=$( printf "%o" $sum ) # and write the output file
signrom.sh has multiple bugs: - the last byte is considered when calculating the existing checksum, but not when computing the correction - apprently the 'expr' expression overflows and produces incorrect results with larger roms - if the checksum happened to be zero, we calculated the correction byte to be 256 Instead of rewriting this in half a line of python, this patch fixes the bugs. Signed-off-by: Avi Kivity <avi@redhat.com> --- pc-bios/optionrom/signrom.sh | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-)