[PATCH tip/core/rcu 30/32] tools/memory-model: Add data-race capabilities to judgelitmus.sh

paulmck
2019-10-03T00:27:35Z

This commit adds functionality to judgelitmus.sh to allow it to handle
both the "DATARACE" markers in the "Result:" comments in litmus tests
and the "Flag data-race" markers in LKMM output. For C-language tests,
if either marker is present, the other must also be as well, at least for
litmus tests having a "Result:" comment. If the LKMM output indicates
a data race, then failures of the Always/Sometimes/Never portion of the
"Result:" prediction are forgiven.

The reason for forgiving "Result:" mispredictions is that data races can
result in "interesting" compiler optimizations, so that all bets are off
in the data-race case.

[ paulmck: Apply Akira Yokosawa feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
tools/memory-model/scripts/judgelitmus.sh | 40 ++++++++++++++++++++++++-------
1 file changed, 32 insertions(+), 8 deletions(-)

diff --git a/tools/memory-model/scripts/judgelitmus.sh b/tools/memory-model/scripts/judgelitmus.sh
index 9abda72..2700481 100755
--- a/tools/memory-model/scripts/judgelitmus.sh
+++ b/tools/memory-model/scripts/judgelitmus.sh
@@ -4,13 +4,19 @@
# Given a .litmus test and the corresponding litmus output file, check
# the .litmus.out file against the "Result:" comment to judge whether the
# test ran correctly. If the --hw argument is omitted, check against the
-# LKMM output, which is assumed to be in file.litmus.out. If this argument
-# is provided, this is assumed to be a hardware test, and the output is
-# assumed to be in file.litmus.HW.out, where "HW" is the --hw argument.
-# In addition, non-Sometimes verification results will be noted, but
-# forgiven. Furthermore, if there is no "Result:" comment but there is
-# an LKMM .litmus.out file, the observation in that file will be used
-# to judge the assembly-language verification.
+# LKMM output, which is assumed to be in file.litmus.out. If either a
+# "DATARACE" marker in the "Result:" comment or a "Flag data-race" marker
+# in the LKMM output is present, the other must also be as well, at least
+# for litmus tests having a "Result:" comment. In this case, a failure of
+# the Always/Sometimes/Never portion of the "Result:" prediction will be
+# noted, but forgiven.
+#
+# If the --hw argument is provided, this is assumed to be a hardware
+# test, and the output is assumed to be in file.litmus.HW.out, where
+# "HW" is the --hw argument. In addition, non-Sometimes verification
+# results will be noted, but forgiven. Furthermore, if there is no
+# "Result:" comment but there is an LKMM .litmus.out file, the observation
+# in that file will be used to judge the assembly-language verification.
#
# Usage:
# judgelitmus.sh file.litmus
@@ -47,9 +53,27 @@ else
echo ' --- ' error: \"$LKMM_DESTDIR/$litmusout is not a readable file
exit 255
fi
+if grep -q '^Flag data-race$' "$LKMM_DESTDIR/$litmusout"
+then
+ datarace_modeled=1
+fi
if grep -q '^ \* Result: ' $litmus
then
outcome=`grep -m 1 '^ \* Result: ' $litmus | awk '{ print $3 }'`
+ if grep -m1 '^ \* Result: .* DATARACE' $litmus
+ then
+ datarace_predicted=1
+ fi
+ if test -n "$datarace_predicted" -a -z "$datarace_modeled" -a -z "$LKMM_HW_MAP_FILE"
+ then
+ echo '!!! Predicted data race not modeled' $litmus
+ exit 252
+ elif test -z "$datarace_predicted" -a -n "$datarace_modeled"
+ then
+ # Note that hardware models currently don't model data races
+ echo '!!! Unexpected data race modeled' $litmus
+ exit 253
+ fi
elif test -n "$LKMM_HW_MAP_FILE" && grep -q '^Observation' $LKMM_DESTDIR/$lkmmout > /dev/null 2>&1
then
outcome=`grep -m 1 '^Observation ' $LKMM_DESTDIR/$lkmmout | awk '{ print $3 }'`
@@ -114,7 +138,7 @@ elif grep '^Observation' $LKMM_DESTDIR/$litmusout | grep -q $outcome || test "$o
then
ret=0
else
- if test -n "$LKMM_HW_MAP_FILE" -a "$outcome" = Sometimes
+ if test \( -n "$LKMM_HW_MAP_FILE" -a "$outcome" = Sometimes \) -o -n "$datarace_modeled"
then
flag="--- Forgiven"
ret=0
--
2.9.5