torture: Indicate which torture.sh runs' bugs are all KCSAN reports

This commit further improves torture.sh run summaries by indicating
which runs' "Bugs:" counts are all KCSAN reports, and further printing
an additional end-of-run summary line when all errors reported in all
runs were KCSAN reports.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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

@@ -414,8 +414,14 @@ nfailures=0
 echo FAILURES: | tee -a $T/log
 if test -s "$T/failures"
 then
-	awk < "$T/failures" -v sq="'" '{ print "echo " sq $0 sq; print "grep Summary: " $2 "/log | sed -e " sq "s/^[^S]*/  /" sq; }' | sh | tee -a $T/log
+	awk < "$T/failures" -v sq="'" '{ print "echo " sq $0 sq; print "grep Summary: " $2 "/log | sed -e " sq "s/^[^S]*/  /" sq; }' | sh | tee -a $T/log | tee "$T/failuresum"
 	nfailures="`wc -l "$T/failures" | awk '{ print $1 }'`"
+	grep "^  Summary: " "$T/failuresum" |
+		grep -v '^  Summary: Bugs: [0-9]* (all bugs kcsan)$' > "$T/nonkcsan"
+	if test -s "$T/nonkcsan"
+	then
+		nonkcsanbug="yes"
+	fi
 	ret=2
 fi
 if test "$do_kcsan" = "yes"
@@ -424,6 +430,10 @@ then
 fi
 echo Started at $startdate, ended at `date`, duration `get_starttime_duration $starttime`. | tee -a $T/log
 echo Summary: Successes: $nsuccesses Failures: $nfailures. | tee -a $T/log
+if test -z "$nonkcsanbug" && test -s "$T/failuresum"
+then
+	echo "  All bugs were KCSAN failures."
+fi
 tdir="`cat $T/successes $T/failures | head -1 | awk '{ print $NF }' | sed -e 's,/[^/]\+/*$,,'`"
 if test -n "$tdir" && test $compress_kasan_vmlinux -gt 0
 then