[PATCHv2 27/59] keys/mktme: Destroy MKTME keys

Kirill A. Shutemov
2019-07-31T15:22:07Z

From: Alison Schofield <alison.schofield@intel.com>

Destroy is a method invoked by the kernel key service when a
userspace key is being removed. (invalidate, revoke, timeout).

During destroy, MKTME wil returned the hardware KeyID to the pool
of available keyids.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
security/keys/mktme_keys.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/security/keys/mktme_keys.c b/security/keys/mktme_keys.c
index beca852db01a..10fcdbf5a08f 100644
--- a/security/keys/mktme_keys.c
+++ b/security/keys/mktme_keys.c
@@ -50,6 +50,23 @@ int mktme_reserve_keyid(struct key *key)
return 0;
}

+static void mktme_release_keyid(int keyid)
+{
+ mktme_map[keyid].state = KEYID_AVAILABLE;
+ mktme_available_keyids++;
+}
+
+int mktme_keyid_from_key(struct key *key)
+{
+ int i;
+
+ for (i = 1; i <= mktme_nr_keyids(); i++) {
+ if (mktme_map[i].key == key)
+ return i;
+ }
+ return 0;
+}
+
enum mktme_opt_id {
OPT_ERROR,
OPT_TYPE,
@@ -62,6 +79,17 @@ static const match_table_t mktme_token = {
{OPT_ERROR, NULL}
};

+/* Key Service Method called when a Userspace Key is garbage collected. */
+static void mktme_destroy_key(struct key *key)
+{
+ int keyid = mktme_keyid_from_key(key);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mktme_lock, flags);
+ mktme_release_keyid(keyid);
+ spin_unlock_irqrestore(&mktme_lock, flags);
+}
+
/* Key Service Method to create a new key. Payload is preparsed. */
int mktme_instantiate_key(struct key *key, struct key_preparsed_payload *prep)
{
@@ -198,6 +226,7 @@ struct key_type key_type_mktme = {
.free_preparse = mktme_free_preparsed_payload,
.instantiate = mktme_instantiate_key,
.describe = user_describe,
+ .destroy = mktme_destroy_key,
};

static int __init init_mktme(void)
--
2.21.0