torture: Add --kcsan argument to top-level kvm.sh script

Although the existing --kconfig argument can be used to run KCSAN for
an rcutorture test, it is not as straightforward as one might like:

	--kconfig "CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y \
		   CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n \
		   CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n \
		   CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 \
		   CONFIG_KCSAN_VERBOSE=y CONFIG_KCSAN_INTERRUPT_WATCHER=y"

This commit therefore adds a "--kcsan" argument that emulates the above
--kconfig command.  Note that if you specify a Kconfig option using
-kconfig that conflicts with one that --kcsan adds, you get whatever
the script and the build system decide to give you.

Cc: Marco Elver <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

Author: paulmckrcu

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

@@ -31,6 +31,7 @@ TORTURE_DEFCONFIG=defconfig
 TORTURE_BOOT_IMAGE=""
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
 TORTURE_KCONFIG_ARG=""
+TORTURE_KCONFIG_KCSAN_ARG=""
 TORTURE_KMAKE_ARG=""
 TORTURE_QEMU_MEM=512
 TORTURE_SHUTDOWN_GRACE=180
@@ -133,6 +134,9 @@ do
 		TORTURE_KCONFIG_ARG="$2"
 		shift
 		;;
+	--kcsan)
+		TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y CONFIG_KCSAN_INTERRUPT_WATCHER=y"; export TORTURE_KCONFIG_KCSAN_ARG
+		;;
 	--kmake-arg)
 		checkarg --kmake-arg "(kernel make arguments)" $# "$2" '.*' '^error$'
 		TORTURE_KMAKE_ARG="$2"
@@ -201,6 +205,9 @@ else
 	exit 1
 fi
 
+TORTURE_KCONFIG_ARG="${TORTURE_KCONFIG_ARG} ${TORTURE_KCONFIG_KCSAN_ARG}"
+TORTURE_KCONFIG_ARG="`echo ${TORTURE_KCONFIG_ARG} | sed -e 's/^ *//' -e 's/ *$//'`"
+
 CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
 
 defaultconfigs="`tr '\012' ' ' < $CONFIGFRAG/CFLIST`"
@@ -310,6 +317,7 @@ TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY
 TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG
 TORTURE_INITRD="$TORTURE_INITRD"; export TORTURE_INITRD
 TORTURE_KCONFIG_ARG="$TORTURE_KCONFIG_ARG"; export TORTURE_KCONFIG_ARG
+TORTURE_KCONFIG_KCSAN_ARG="$TORTURE_KCONFIG_KCSAN_ARG"; export TORTURE_KCONFIG_KCSAN_ARG
 TORTURE_KMAKE_ARG="$TORTURE_KMAKE_ARG"; export TORTURE_KMAKE_ARG
 TORTURE_QEMU_CMD="$TORTURE_QEMU_CMD"; export TORTURE_QEMU_CMD
 TORTURE_QEMU_INTERACTIVE="$TORTURE_QEMU_INTERACTIVE"; export TORTURE_QEMU_INTERACTIVE