[v3] selftests/lkdtm: Add tests for LKDTM targets
diff mbox series

Message ID 202001092059.4857C4F@keescook
State Mainlined
Commit 46d1a0f03d6611659420c3ddde28da3f3f134a3f
Headers show
  • [v3] selftests/lkdtm: Add tests for LKDTM targets
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Commit Message

Kees Cook Jan. 10, 2020, 5:02 a.m. UTC
This adds a basic framework for running all the "safe" LKDTM tests. This
will allow easy introspection into any selftest logs to examine the
results of most LKDTM tests.

Signed-off-by: Kees Cook <keescook@chromium.org>
v3: replace open-coded "4" with $KSELFTEST_SKIP_TEXT (shuah), add DOUBLE_FAULT
v2: https://lore.kernel.org/lkml/201912301453.19D686EE6@keescook
v1: https://lore.kernel.org/lkml/201905091013.E228F0F0BE@keescook
 MAINTAINERS                             |  1 +
 tools/testing/selftests/Makefile        |  1 +
 tools/testing/selftests/lkdtm/Makefile  | 12 ++++
 tools/testing/selftests/lkdtm/config    |  1 +
 tools/testing/selftests/lkdtm/run.sh    | 92 +++++++++++++++++++++++++
 tools/testing/selftests/lkdtm/tests.txt | 71 +++++++++++++++++++
 6 files changed, 178 insertions(+)
 create mode 100644 tools/testing/selftests/lkdtm/Makefile
 create mode 100644 tools/testing/selftests/lkdtm/config
 create mode 100755 tools/testing/selftests/lkdtm/run.sh
 create mode 100644 tools/testing/selftests/lkdtm/tests.txt

diff mbox series

index cc0a4a8ae06a..eacc00c6cfd5 100644
@@ -9578,6 +9578,7 @@  LINUX KERNEL DUMP TEST MODULE (LKDTM)
 M:	Kees Cook <keescook@chromium.org>
 S:	Maintained
 F:	drivers/misc/lkdtm/*
+F:	tools/testing/selftests/lkdtm/*
 M:	Alan Stern <stern@rowland.harvard.edu>
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index b001c602414b..f0b02a12ba39 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -26,6 +26,7 @@  TARGETS += kexec
 TARGETS += kvm
 TARGETS += lib
 TARGETS += livepatch
+TARGETS += lkdtm
 TARGETS += membarrier
 TARGETS += memfd
 TARGETS += memory-hotplug
diff --git a/tools/testing/selftests/lkdtm/Makefile b/tools/testing/selftests/lkdtm/Makefile
new file mode 100644
index 000000000000..1bcc9ee990eb
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/Makefile
@@ -0,0 +1,12 @@ 
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for LKDTM regression tests
+include ../lib.mk
+# NOTE: $(OUTPUT) won't get default value if used before lib.mk
+TEST_FILES := tests.txt
+TEST_GEN_PROGS = $(patsubst %,$(OUTPUT)/%.sh,$(shell awk '{print $$1}' tests.txt | sed -e 's/\#//'))
+$(OUTPUT)/%: run.sh tests.txt
+	install -m 0744 run.sh $@
diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config
new file mode 100644
index 000000000000..d874990e442b
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/config
@@ -0,0 +1 @@ 
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh
new file mode 100755
index 000000000000..dadf819148a4
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/run.sh
@@ -0,0 +1,92 @@ 
+# SPDX-License-Identifier: GPL-2.0
+# This reads tests.txt for the list of LKDTM tests to invoke. Any marked
+# with a leading "#" are skipped. The rest of the line after the
+# test name is either the text to look for in dmesg for a "success",
+# or the rationale for why a test is marked to be skipped.
+set -e
+# Verify we have LKDTM available in the kernel.
+if [ ! -r $TRIGGER ] ; then
+	/sbin/modprobe -q lkdtm || true
+	if [ ! -r $TRIGGER ] ; then
+		echo "Cannot find $TRIGGER (missing CONFIG_LKDTM?)"
+	else
+		echo "Cannot write $TRIGGER (need to run as root?)"
+	fi
+	# Skip this test
+# Figure out which test to run from our script name.
+test=$(basename $0 .sh)
+# Look up details about the test from master list of LKDTM tests.
+line=$(egrep '^#?'"$test"'\b' tests.txt)
+if [ -z "$line" ]; then
+	echo "Skipped: missing test '$test' in tests.txt"
+# Check that the test is known to LKDTM.
+if ! egrep -q '^'"$test"'$' "$TRIGGER" ; then
+	echo "Skipped: test '$test' missing in $TRIGGER!"
+# Extract notes/expected output from test list.
+test=$(echo "$line" | cut -d" " -f1)
+if echo "$line" | grep -q ' ' ; then
+	expect=$(echo "$line" | cut -d" " -f2-)
+	expect=""
+# If the test is commented out, report a skip
+if echo "$test" | grep -q '^#' ; then
+	test=$(echo "$test" | cut -c2-)
+	if [ -z "$expect" ]; then
+		expect="crashes entire system"
+	fi
+	echo "Skipping $test: $expect"
+# If no expected output given, assume an Oops with back trace is success.
+if [ -z "$expect" ]; then
+	expect="call trace:"
+# Clear out dmesg for output reporting
+dmesg -c >/dev/null
+# Prepare log for report checking
+LOG=$(mktemp --tmpdir -t lkdtm-XXXXXX)
+cleanup() {
+	rm -f "$LOG"
+trap cleanup EXIT
+# Most shells yell about signals and we're expecting the "cat" process
+# to usually be killed by the kernel. So we have to run it in a sub-shell
+# and silence errors.
+($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true
+# Record and dump the results
+dmesg -c >"$LOG"
+cat "$LOG"
+# Check for expected output
+if egrep -qi "$expect" "$LOG" ; then
+	echo "$test: saw '$expect': ok"
+	exit 0
+	if egrep -qi XFAIL: "$LOG" ; then
+		echo "$test: saw 'XFAIL': [SKIP]"
+	else
+		echo "$test: missing '$expect': [FAIL]"
+		exit 1
+	fi
diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt
new file mode 100644
index 000000000000..92ca32143ae5
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/tests.txt
@@ -0,0 +1,71 @@ 
+BUG kernel BUG at
+WARNING_MESSAGE message trigger
+#LOOP Hangs the system
+#EXHAUST_STACK Corrupts memory on failure
+#CORRUPT_STACK Crashes entire system on success
+#CORRUPT_STACK_STRONG Crashes entire system on success
+CORRUPT_LIST_ADD list_add corruption
+CORRUPT_LIST_DEL list_del corruption
+CORRUPT_USER_DS Invalid address limit on user-mode return
+UNSET_SMEP CR4 bits went missing
+#OVERWRITE_ALLOCATION Corrupts memory on failure
+#WRITE_AFTER_FREE Corrupts memory on failure
+#WRITE_BUDDY_AFTER_FREE Corrupts memory on failure
+#SOFTLOCKUP Hangs the system
+#HARDLOCKUP Hangs the system
+#SPINLOCKUP Hangs the system
+#HUNG_TASK Hangs the system
+REFCOUNT_DEC_NEGATIVE Negative detected: saturated
+REFCOUNT_DEC_AND_TEST_NEGATIVE Negative detected: saturated
+REFCOUNT_SUB_AND_TEST_NEGATIVE Negative detected: saturated
+REFCOUNT_INC_SATURATED Saturation detected: still saturated
+REFCOUNT_DEC_SATURATED Saturation detected: still saturated
+REFCOUNT_ADD_SATURATED Saturation detected: still saturated
+REFCOUNT_DEC_AND_TEST_SATURATED Saturation detected: still saturated
+REFCOUNT_SUB_AND_TEST_SATURATED Saturation detected: still saturated
+#REFCOUNT_TIMING timing only
+#ATOMIC_TIMING timing only
+STACKLEAK_ERASING OK: the rest of the thread stack is properly erased