[PATCH 4/6] ima: Implement ima_shutdown and register it as a reboot_notifier

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

Implement ima_shutdown so that we can release the tpm_chip before
devices are shut down. Register it as a low-priority reboot_notifier.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
---
 security/integrity/ima/ima_init.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 29b72cd2502e..8a5258eb32b6 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -21,6 +21,7 @@
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/err.h>
+#include <linux/reboot.h>
 
 #include "ima.h"
 
@@ -104,11 +105,24 @@ void __init ima_load_x509(void)
 }
 #endif
 
+static int ima_shutdown(struct notifier_block *this, unsigned long action,
+			void *data)
+{
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block ima_reboot_notifier = {
+	.notifier_call = ima_shutdown,
+	.priority = 0,
+};
+
 int __init ima_init(void)
 {
 	u8 pcr_i[TPM_DIGEST_SIZE];
 	int rc;
 
+	register_reboot_notifier(&ima_reboot_notifier);
+
 	ima_used_chip = 0;
 	rc = tpm_pcr_read(NULL, 0, pcr_i);
 	if (rc == 0)
-- 
2.13.6