torture: Allow variations of "defconfig" to be specified

Some environments require some variation on "make defconfig" to initialize
the .config file.  This commit therefore adds a --defconfig argument to
allow this to be specified.  The default value is of course "defconfig".

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

tools/testing/selftests/rcutorture/bin/configinit.sh

@@ -62,7 +62,7 @@ grep '^grep' < $T/u.sh > $T/upd.sh
 echo "cat - $c" >> $T/upd.sh
 make mrproper
 make $buildloc distclean > $builddir/Make.distclean 2>&1
-make $buildloc defconfig > $builddir/Make.defconfig.out 2>&1
+make $buildloc $TORTURE_DEFCONFIG > $builddir/Make.defconfig.out 2>&1
 mv $builddir/.config $builddir/.config.sav
 sh $T/upd.sh < $builddir/.config.sav > $builddir/.config
 cp $builddir/.config $builddir/.config.new

tools/testing/selftests/rcutorture/bin/kvm.sh

@@ -38,6 +38,7 @@ dur=30
 dryrun=""
 KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
 PATH=${KVM}/bin:$PATH; export PATH
+TORTURE_DEFCONFIG=defconfig
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
 RCU_KMAKE_ARG=""; export RCU_KMAKE_ARG
 TORTURE_SUITE=rcu
@@ -56,6 +57,7 @@ usage () {
 	echo "       --configs \"config-file list\""
 	echo "       --cpus N"
 	echo "       --datestamp string"
+	echo "       --defconfig string"
 	echo "       --dryrun sched|script"
 	echo "       --duration minutes"
 	echo "       --interactive"
@@ -96,6 +98,11 @@ do
 		ds=$2
 		shift
 		;;
+	--defconfig)
+		checkarg --defconfig "defconfigtype" "$#" "$2" '^[^/][^/]*$' '^--'
+		TORTURE_DEFCONFIG=$2
+		shift
+		;;
 	--dryrun)
 		checkarg --dryrun "sched|script" $# "$2" 'sched\|script' '^--'
 		dryrun=$2
@@ -259,6 +266,7 @@ END {
 # Generate a script to execute the tests in appropriate batches.
 cat << ___EOF___ > $T/script
 TORTURE_SUITE="$TORTURE_SUITE"; export TORTURE_SUITE
+TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG
 ___EOF___
 awk < $T/cfgcpu.pack \
 	-v CONFIGDIR="$CONFIGFRAG/$kversion/" \