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Subject[PATCH, RFC 26/62] keys/mktme: Move the MKTME payload into a cache aligned structure
Date
From: Alison Schofield <alison.schofield@intel.com>

In preparation for programming the key into the hardware, move
the key payload into a cache aligned structure. This alignment
is a requirement of the MKTME hardware.

Use the slab allocator to have this structure readily available.

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 | 39 ++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/security/keys/mktme_keys.c b/security/keys/mktme_keys.c
index 14bc4e600978..a7ca32865a1c 100644
--- a/security/keys/mktme_keys.c
+++ b/security/keys/mktme_keys.c
@@ -15,6 +15,7 @@
#include "internal.h"

static DEFINE_SPINLOCK(mktme_lock);
+struct kmem_cache *mktme_prog_cache; /* Hardware programming cache */

/* 1:1 Mapping between Userspace Keys (struct key) and Hardware KeyIDs */
struct mktme_mapping {
@@ -97,6 +98,27 @@ struct mktme_payload {
u8 tweak_key[MKTME_AES_XTS_SIZE];
};

+/* Copy the payload to the HW programming structure and program this KeyID */
+static int mktme_program_keyid(int keyid, struct mktme_payload *payload)
+{
+ struct mktme_key_program *kprog = NULL;
+ int ret;
+
+ kprog = kmem_cache_zalloc(mktme_prog_cache, GFP_ATOMIC);
+ if (!kprog)
+ return -ENOMEM;
+
+ /* Hardware programming requires cached aligned struct */
+ kprog->keyid = keyid;
+ kprog->keyid_ctrl = payload->keyid_ctrl;
+ memcpy(kprog->key_field_1, payload->data_key, MKTME_AES_XTS_SIZE);
+ memcpy(kprog->key_field_2, payload->tweak_key, MKTME_AES_XTS_SIZE);
+
+ ret = MKTME_PROG_SUCCESS; /* Future programming call */
+ kmem_cache_free(mktme_prog_cache, kprog);
+ return ret;
+}
+
/* Key Service Method called when a Userspace Key is garbage collected. */
static void mktme_destroy_key(struct key *key)
{
@@ -106,6 +128,7 @@ static void mktme_destroy_key(struct key *key)
/* Key Service Method to create a new key. Payload is preparsed. */
int mktme_instantiate_key(struct key *key, struct key_preparsed_payload *prep)
{
+ struct mktme_payload *payload = prep->payload.data[0];
unsigned long flags;
int keyid;

@@ -114,7 +137,14 @@ int mktme_instantiate_key(struct key *key, struct key_preparsed_payload *prep)
spin_unlock_irqrestore(&mktme_lock, flags);
if (!keyid)
return -ENOKEY;
- return 0;
+
+ if (!mktme_program_keyid(keyid, payload))
+ return MKTME_PROG_SUCCESS;
+
+ spin_lock_irqsave(&mktme_lock, flags);
+ mktme_release_keyid(keyid);
+ spin_unlock_irqrestore(&mktme_lock, flags);
+ return -ENOKEY;
}

/* Make sure arguments are correct for the TYPE of key requested */
@@ -275,10 +305,15 @@ static int __init init_mktme(void)
if (mktme_map_alloc())
return -ENOMEM;

+ /* Used to program the hardware key tables */
+ mktme_prog_cache = KMEM_CACHE(mktme_key_program, SLAB_PANIC);
+ if (!mktme_prog_cache)
+ goto free_map;
+
ret = register_key_type(&key_type_mktme);
if (!ret)
return ret; /* SUCCESS */
-
+free_map:
kvfree(mktme_map);

return -ENOMEM;
--
2.20.1
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