Merge tag 'lkdtm-v5.17-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into char-misc-next

Kees writes:

lkdtm updates for v5.17-rc1

- Fix printk() usage during recursion (Ard Biesheuvel)
- Fix rodata section to actually have contents (Christophe Leroy)
- Add notes about lkdtm_kernel_info usage (Kees Cook)
- Avoid stack-entropy selftest when LKDTM is disabled (Misono Tomohiro)

* tag 'lkdtm-v5.17-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  selftest/lkdtm: Skip stack-entropy test if lkdtm is not available
  lkdtm: Fix content of section containing lkdtm_rodata_do_nothing()
  lkdtm: avoid printk() in recursive_loop()
  lkdtm: Note that lkdtm_kernel_info should be removed in the future

1 files changed, 15 insertions, 1 deletions

diff --git a/tools/testing/selftests/lkdtm/stack-entropy.sh b/tools/testing/selftests/lkdtm/stack-entropy.sh
index 1b4d95d575f8..14fedeef762e 100755
--- a/tools/testing/selftests/lkdtm/stack-entropy.sh
+++ b/tools/testing/selftests/lkdtm/stack-entropy.sh
@@ -4,13 +4,27 @@
 # 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" >/sys/kernel/debug/provoke-crash/DIRECT
+        echo "REPORT_STACK" > $TRIGGER
 	if [ -t 1 ]; then
 		percent=$(( 100 * $i / $samples ))
 		if [ "$percent" -ne "$report" ]; then