selftests/kexec: make kexec_load test independent of IMA being enabled

Verify IMA is enabled before failing tests or emitting irrelevant
messages.
Suggested-by: NDave Young <dyoung@redhat.com>
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
Reviewed-by: NDave Young <dyoung@redhat.com>
Reviewed-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NShuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/kexec/test_kexec_load.sh

 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
-# Loading a kernel image via the kexec_load syscall should fail
-# when the kernel is CONFIG_KEXEC_VERIFY_SIG enabled and the system
-# is booted in secureboot mode.
+#
+# Prevent loading a kernel image via the kexec_load syscall when
+# signatures are required.  (Dependent on CONFIG_IMA_ARCH_POLICY.)
 
 TEST="$0"
 . ./kexec_common_lib.sh
@@ -18,20 +18,28 @@ if [ $? -eq 0 ]; then
 	log_skip "kexec_load is not enabled"
 fi
 
+kconfig_enabled "CONFIG_IMA_APPRAISE=y" "IMA enabled"
+ima_appraise=$?
+
+kconfig_enabled "CONFIG_IMA_ARCH_POLICY=y" \
+	"IMA architecture specific policy enabled"
+arch_policy=$?
+
 get_secureboot_mode
 secureboot=$?
 
-# kexec_load should fail in secure boot mode
+# kexec_load should fail in secure boot mode and CONFIG_IMA_ARCH_POLICY enabled
 kexec --load $KERNEL_IMAGE > /dev/null 2>&1
 if [ $? -eq 0 ]; then
 	kexec --unload
-	if [ $secureboot -eq 1 ]; then
+	if [ $secureboot -eq 1 ] && [ $arch_policy -eq 1 ]; then
 		log_fail "kexec_load succeeded"
-	else
-		log_pass "kexec_load succeeded"
+	elif [ $ima_appraise -eq 0 -o $arch_policy -eq 0 ]; then
+		log_info "Either IMA or the IMA arch policy is not enabled"
 	fi
+	log_pass "kexec_load succeeded"
 else
-	if [ $secureboot -eq 1 ]; then
+	if [ $secureboot -eq 1 ] && [ $arch_policy -eq 1 ] ; then
 		log_pass "kexec_load failed"
 	else
 		log_fail "kexec_load failed"