torture: Make torture.sh KCSAN runs set CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE=y

The RCU_TORTURE_TEST_CHK_RDR_STATE Kconfig option is used for low-level
debugging of rcutorture's generation of overlapping and nested RCU
readers.  It incurs significant overhead, and is thus not to be used
lightly.  But if it is not tested regularly, it won't be there when it
is needed, for example, it would have found an rcutorture bug in the
testing of srcu_up_read().

This commit therefore uses CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE=y when
building KCSAN kernels, but only for the --do-rcutorture case.

Reported-by: kernel test robot <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Signed-off-by: Neeraj Upadhyay (AMD) <[email protected]>

Author: paulmckrcu

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

@@ -378,7 +378,12 @@ function torture_set {
 			kcsan_kmake_tag="--kmake-args"
 			cur_kcsan_kmake_args="$kcsan_kmake_args"
 		fi
-		torture_one "$@" --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" $kcsan_kmake_tag $cur_kcsan_kmake_args --kcsan
+		chk_rdr_state=
+		if test "${flavor}" = rcutorture
+		then
+			chk_rdr_state="CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE=y"
+		fi
+		torture_one "$@" --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y ${chk_rdr_state}" $kcsan_kmake_tag $cur_kcsan_kmake_args --kcsan
 		mv $T/last-resdir $T/last-resdir-kcsan || :
 	fi
 }