linux-kselftest-5.7-rc6

This Kselftest update for Linux 5.7-rc6 consists of
 
 - lkdtm runner fixes to prevent dmesg clearing and shellcheck errors
 - ftrace test handling when test module doesn't exist
 - nsfs test fix to replace zero-length array with flexible-array
 - dmabuf-heaps test fix to return clear error value
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Merge tag 'linux-kselftest-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:

 - lkdtm runner fixes to prevent dmesg clearing and shellcheck errors

 - ftrace test handling when test module doesn't exist

 - nsfs test fix to replace zero-length array with flexible-array

 - dmabuf-heaps test fix to return clear error value

* tag 'linux-kselftest-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/lkdtm: Use grep -E instead of egrep
  selftests/lkdtm: Don't clear dmesg when running tests
  selftests/ftrace: mark irqsoff_tracer.tc test as unresolved if the test module does not exist
  tools/testing: Replace zero-length array with flexible-array
  kselftests: dmabuf-heaps: Fix confused return value on expected error testing

tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c

@@ -351,6 +351,7 @@ static int test_alloc_errors(char *heap_name)
 	}
 
 	printf("Expected error checking passed\n");
+	ret = 0;
 out:
 	if (dmabuf_fd >= 0)
 		close(dmabuf_fd);

tools/testing/selftests/ftrace/test.d/preemptirq/irqsoff_tracer.tc

@@ -17,7 +17,14 @@ unsup() { #msg
     exit_unsupported
 }
 
-modprobe $MOD || unsup "$MOD module not available"
+unres() { #msg
+    reset_tracer
+    rmmod $MOD || true
+    echo $1
+    exit_unresolved
+}
+
+modprobe $MOD || unres "$MOD module not available"
 rmmod $MOD
 
 grep -q "preemptoff" available_tracers || unsup "preemptoff tracer not enabled"

tools/testing/selftests/lkdtm/run.sh

@@ -25,13 +25,13 @@ 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 $KSELFTEST_SKIP_TEST
 fi
@@ -59,30 +59,32 @@ if [ -z "$expect" ]; then
 	expect="call trace:"
 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
 
+# Save existing dmesg so we can detect new content below
+dmesg > "$DMESG"
+
 # Most shells yell about signals and we're expecting the "cat" process
 # to usually be killed by the kernel. So we have to run it in a sub-shell
 # and silence errors.
 ($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true
 
 # Record and dump the results
-dmesg -c >"$LOG"
+dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$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

tools/testing/selftests/nsfs/pidns.c

@@ -27,7 +27,7 @@
 #define __stack_aligned__	__attribute__((aligned(16)))
 struct cr_clone_arg {
 	char stack[128] __stack_aligned__;
-	char stack_ptr[0];
+	char stack_ptr[];
 };
 
 static int child(void *args)