[PATCH v8 4/8] powerpc/ima: add measurement rules to ima arch specific policy

[Nayna Jain]

This patch adds the measurement rules to the arch specific policies on
trusted boot enabled systems.

Signed-off-by: Nayna Jain <na...@linux.ibm.com>
---
 arch/powerpc/kernel/ima_arch.c | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c
index 65d82ee74ea4..710872ea8f35 100644
--- a/arch/powerpc/kernel/ima_arch.c
+++ b/arch/powerpc/kernel/ima_arch.c
@@ -26,6 +26,32 @@ static const char *const secure_rules[] = {
        NULL
 };
 
+/*
+ * The "measure_rules" are enabled only on "trustedboot" enabled systems.
+ * These rules add the kexec kernel image and kernel modules file hashes to
+ * the IMA measurement list.
+ */
+static const char *const trusted_rules[] = {
+       "measure func=KEXEC_KERNEL_CHECK",
+       "measure func=MODULE_CHECK",
+       NULL
+};
+
+/*
+ * The "secure_and_trusted_rules" contains rules for both the secure boot and
+ * trusted boot. The "template=ima-modsig" option includes the appended
+ * signature, when available, in the IMA measurement list.
+ */
+static const char *const secure_and_trusted_rules[] = {
+       "measure func=KEXEC_KERNEL_CHECK template=ima-modsig",
+       "measure func=MODULE_CHECK template=ima-modsig",
+       "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig",
+#ifndef CONFIG_MODULE_SIG_FORCE
+       "appraise func=MODULE_CHECK appraise_type=imasig|modsig",
+#endif
+       NULL
+};
+
 /*
  * Returns the relevant IMA arch-specific policies based on the system secure
  * boot state.
@@ -33,7 +59,13 @@ static const char *const secure_rules[] = {
 const char *const *arch_get_ima_policy(void)
 {
        if (is_ppc_secureboot_enabled())
-               return secure_rules;
+               if (is_ppc_trustedboot_enabled())
+                       return secure_and_trusted_rules;
+               else
+                       return secure_rules;
+       else
+               if (is_ppc_trustedboot_enabled())
+                       return trusted_rules;
 
        return NULL;
 }
-- 
2.20.1