[PATCH] Add checking num-threads of makedumpfile

[Minfei Huang]

On 08/25/15 at 02:17pm, "Zhou, Wenjian/周文剑" wrote:
> >>>>+	if [ $? -eq 0 ];then
> >>>>+		local nr_cpus=1
> >>>>+		local num_threads=0
> >>>>+		local core_collector=`grep -v "^#" $KDUMP_CONFIG_FILE | grep "^core_collector"`
> >>>>+
> >>>>+		num_threads=`echo ${core_collector#*--num-threads} | awk '{print $1}'`
> >>>>+		nr_cpus=`echo ${KDUMP_COMMANDLINE_APPEND#*nr_cpus=} | awk '{print $1}'`
> >>>>+
> >>>>+		test $num_threads -ge $nr_cpus &> /dev/null
> >>>>+		if [ $? -eq 0 ];then
> >>>
> >>>To keep the style, it is better to use "if [ $a -ge $b ]".
> >>>
> >>
> >>Using "test" is to handle the situation that the $num_threads or $nr_cpus is not an integer.
> >>
> >
> >Is it allowed for $num_threads or $nr_cpus, if the value is not the
> >integer?
> >
> 
> Of course not integer is invalid. But the value of num_threads won't be checked
> until makedumpfile is executed.
> If user sets "core_collector makedumpfile --num-threads a" in kdump.conf, it will
> lead to a fault here.
> 

I think it is fine without validating the type of num-threads, since
makedumpfile will do this work. 

kdump does not check other usages of makedumpfile as well. It is better
to wrap a new function to check it in kdumpctl, if you want to try to
validate the usage value.

Thanks
Minfei

> >>BTW, should we add some descriptions to this feature of makedumpfile in some where?
> >
> >IMO, it is appropriate to document it in the makedumpfile manpage, like
> >the feature --split. For kdump, we only document the default usages for
> >makedumpfile in kexec-kdump-howto.txt.
> >