6 files changed, 123 insertions, 24 deletions
diff --git a/tools/testing/selftests/lkdtm/.gitignore b/tools/testing/selftests/lkdtm/.gitignore
index f26212605b6b..d4b0be857deb 100644
--- a/tools/testing/selftests/lkdtm/.gitignore
+++ b/tools/testing/selftests/lkdtm/.gitignore
@@ -1,2 +1,3 @@
 *.sh
 !run.sh
+!stack-entropy.sh
diff --git a/tools/testing/selftests/lkdtm/Makefile b/tools/testing/selftests/lkdtm/Makefile
index 1bcc9ee990eb..c71109ceeb2d 100644
--- a/tools/testing/selftests/lkdtm/Makefile
+++ b/tools/testing/selftests/lkdtm/Makefile
@@ -5,6 +5,7 @@ include ../lib.mk
 
 # NOTE: $(OUTPUT) won't get default value if used before lib.mk
 TEST_FILES := tests.txt
+TEST_PROGS := stack-entropy.sh
 TEST_GEN_PROGS = $(patsubst %,$(OUTPUT)/%.sh,$(shell awk '{print $$1}' tests.txt | sed -e 's/\#//'))
 all: $(TEST_GEN_PROGS)
 
diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config
index d874990e442b..5d52f64dfb43 100644
--- a/tools/testing/selftests/lkdtm/config
+++ b/tools/testing/selftests/lkdtm/config
@@ -1 +1,15 @@
 CONFIG_LKDTM=y
+CONFIG_DEBUG_LIST=y
+CONFIG_SLAB_FREELIST_HARDENED=y
+CONFIG_FORTIFY_SOURCE=y
+CONFIG_GCC_PLUGIN_STACKLEAK=y
+CONFIG_HARDENED_USERCOPY=y
+CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y
+CONFIG_INIT_ON_FREE_DEFAULT_ON=y
+CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y
+CONFIG_UBSAN=y
+CONFIG_UBSAN_BOUNDS=y
+CONFIG_UBSAN_TRAP=y
+CONFIG_STACKPROTECTOR_STRONG=y
+CONFIG_SLUB_DEBUG=y
+CONFIG_SLUB_DEBUG_ON=y
diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh
index dadf819148a4..95e904959207 100755
--- a/tools/testing/selftests/lkdtm/run.sh
+++ b/tools/testing/selftests/lkdtm/run.sh
@@ -8,6 +8,7 @@
 #
 set -e
 TRIGGER=/sys/kernel/debug/provoke-crash/DIRECT
+CLEAR_ONCE=/sys/kernel/debug/clear_warn_once
 KSELFTEST_SKIP_TEST=4
 
 # Verify we have LKDTM available in the kernel.
@@ -25,13 +26,13 @@ fi
 # 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 '^#?'"$test"'\b' tests.txt)
+line=$(grep -E '^#?'"$test"'\b' tests.txt)
 if [ -z "$line" ]; then
 	echo "Skipped: missing test '$test' in tests.txt"
 	exit $KSELFTEST_SKIP_TEST
 fi
 # Check that the test is known to LKDTM.
-if ! egrep -q '^'"$test"'$' "$TRIGGER" ; then
+if ! grep -E -q '^'"$test"'$' "$TRIGGER" ; then
 	echo "Skipped: test '$test' missing in $TRIGGER!"
 	exit $KSELFTEST_SKIP_TEST
 fi
@@ -55,34 +56,53 @@ if echo "$test" | grep -q '^#' ; then
 fi
 
 # If no expected output given, assume an Oops with back trace is success.
+repeat=1
 if [ -z "$expect" ]; then
 	expect="call trace:"
+else
+	if echo "$expect" | grep -q '^repeat:' ; then
+		repeat=$(echo "$expect" | cut -d' ' -f1 | cut -d: -f2)
+		expect=$(echo "$expect" | cut -d' ' -f2-)
+	fi
 fi
 
-# Clear out dmesg for output reporting
-dmesg -c >/dev/null
-
 # Prepare log for report checking
-LOG=$(mktemp --tmpdir -t lkdtm-XXXXXX)
+LOG=$(mktemp --tmpdir -t lkdtm-log-XXXXXX)
+DMESG=$(mktemp --tmpdir -t lkdtm-dmesg-XXXXXX)
 cleanup() {
-	rm -f "$LOG"
+	rm -f "$LOG" "$DMESG"
 }
 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
+# Reset WARN_ONCE counters so we trip it each time this runs.
+if [ -w $CLEAR_ONCE ] ; then
+	echo 1 > $CLEAR_ONCE
+fi
+
+# Save existing dmesg so we can detect new content below
+dmesg > "$DMESG"
+
+# Since the kernel is likely killing the process writing to the trigger
+# file, it must not be the script's shell itself. i.e. we cannot do:
+#     echo "$test" >"$TRIGGER"
+# Instead, use "cat" to take the signal. Since the shell will yell about
+# the signal that killed the subprocess, we must ignore the failure and
+# continue. However we don't silence stderr since there might be other
+# useful details reported there in the case of other unexpected conditions.
+for i in $(seq 1 $repeat); do
+	echo "$test" | cat >"$TRIGGER" || true
+done
 
 # Record and dump the results
-dmesg -c >"$LOG"
+dmesg | comm --nocheck-order -13 "$DMESG" - > "$LOG" || true
+
 cat "$LOG"
 # Check for expected output
-if egrep -qi "$expect" "$LOG" ; then
+if grep -E -qi "$expect" "$LOG" ; then
 	echo "$test: saw '$expect': ok"
 	exit 0
 else
-	if egrep -qi XFAIL: "$LOG" ; then
+	if grep -E -qi XFAIL: "$LOG" ; then
 		echo "$test: saw 'XFAIL': [SKIP]"
 		exit $KSELFTEST_SKIP_TEST
 	else
diff --git a/tools/testing/selftests/lkdtm/stack-entropy.sh b/tools/testing/selftests/lkdtm/stack-entropy.sh
new file mode 100755
index 000000000000..14fedeef762e
--- /dev/null
+++ b/tools/testing/selftests/lkdtm/stack-entropy.sh
@@ -0,0 +1,51 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Measure kernel stack entropy by sampling via LKDTM's REPORT_STACK test.
+set -e
+samples="${1:-1000}"
+TRIGGER=/sys/kernel/debug/provoke-crash/DIRECT
+KSELFTEST_SKIP_TEST=4
+
+# 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
+	exit $KSELFTEST_SKIP_TEST
+fi
+
+# Capture dmesg continuously since it may fill up depending on sample size.
+log=$(mktemp -t stack-entropy-XXXXXX)
+dmesg --follow >"$log" & pid=$!
+report=-1
+for i in $(seq 1 $samples); do
+        echo "REPORT_STACK" > $TRIGGER
+	if [ -t 1 ]; then
+		percent=$(( 100 * $i / $samples ))
+		if [ "$percent" -ne "$report" ]; then
+			/bin/echo -en "$percent%\r"
+			report="$percent"
+		fi
+	fi
+done
+kill "$pid"
+
+# Count unique offsets since last run.
+seen=$(tac "$log" | grep -m1 -B"$samples"0 'Starting stack offset' | \
+	grep 'Stack offset' | awk '{print $NF}' | sort | uniq -c | wc -l)
+bits=$(echo "obase=2; $seen" | bc | wc -L)
+echo "Bits of stack entropy: $bits"
+rm -f "$log"
+
+# We would expect any functional stack randomization to be at least 5 bits.
+if [ "$bits" -lt 5 ]; then
+	echo "Stack entropy is low! Booted without 'randomize_kstack_offset=y'?"
+	exit 1
+else
+	exit 0
+fi
diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt
index 92ca32143ae5..607b8d7e3ea3 100644
--- a/tools/testing/selftests/lkdtm/tests.txt
+++ b/tools/testing/selftests/lkdtm/tests.txt
@@ -7,19 +7,24 @@ EXCEPTION
 #EXHAUST_STACK Corrupts memory on failure
 #CORRUPT_STACK Crashes entire system on success
 #CORRUPT_STACK_STRONG Crashes entire system on success
+ARRAY_BOUNDS
 CORRUPT_LIST_ADD list_add corruption
 CORRUPT_LIST_DEL list_del corruption
-CORRUPT_USER_DS Invalid address limit on user-mode return
 STACK_GUARD_PAGE_LEADING
 STACK_GUARD_PAGE_TRAILING
-UNSET_SMEP CR4 bits went missing
+REPORT_STACK_CANARY repeat:2 ok: stack canaries differ
+UNSET_SMEP pinned CR4 bits changed:
 DOUBLE_FAULT
+CORRUPT_PAC
 UNALIGNED_LOAD_STORE_WRITE
-#OVERWRITE_ALLOCATION Corrupts memory on failure
+SLAB_LINEAR_OVERFLOW
+VMALLOC_LINEAR_OVERFLOW
 #WRITE_AFTER_FREE Corrupts memory on failure
-READ_AFTER_FREE
+READ_AFTER_FREE call trace:|Memory correctly poisoned
 #WRITE_BUDDY_AFTER_FREE Corrupts memory on failure
-READ_BUDDY_AFTER_FREE
+READ_BUDDY_AFTER_FREE call trace:|Memory correctly poisoned
+SLAB_INIT_ON_ALLOC Memory appears initialized
+BUDDY_INIT_ON_ALLOC Memory appears initialized
 SLAB_FREE_DOUBLE
 SLAB_FREE_CROSS
 SLAB_FREE_PAGE
@@ -39,6 +44,7 @@ ACCESS_NULL
 WRITE_RO
 WRITE_RO_AFTER_INIT
 WRITE_KERN
+WRITE_OPD
 REFCOUNT_INC_OVERFLOW
 REFCOUNT_ADD_OVERFLOW
 REFCOUNT_INC_NOT_ZERO_OVERFLOW
@@ -58,14 +64,20 @@ 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
-USERCOPY_HEAP_SIZE_TO
-USERCOPY_HEAP_SIZE_FROM
-USERCOPY_HEAP_WHITELIST_TO
-USERCOPY_HEAP_WHITELIST_FROM
+USERCOPY_SLAB_SIZE_TO
+USERCOPY_SLAB_SIZE_FROM
+USERCOPY_SLAB_WHITELIST_TO
+USERCOPY_SLAB_WHITELIST_FROM
 USERCOPY_STACK_FRAME_TO
 USERCOPY_STACK_FRAME_FROM
 USERCOPY_STACK_BEYOND
 USERCOPY_KERNEL
-USERCOPY_KERNEL_DS
 STACKLEAK_ERASING OK: the rest of the thread stack is properly erased
 CFI_FORWARD_PROTO
+CFI_BACKWARD call trace:|ok: control flow unchanged
+FORTIFY_STRSCPY detected buffer overflow
+FORTIFY_STR_OBJECT detected buffer overflow
+FORTIFY_STR_MEMBER detected buffer overflow
+FORTIFY_MEM_OBJECT detected buffer overflow
+FORTIFY_MEM_MEMBER detected field-spanning write
+PPC_SLB_MULTIHIT Recovered