hc
2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376
kernel/block/keyslot-manager.c
....@@ -10,7 +10,7 @@
1010 * into which encryption contexts may be programmed, and requests can be tagged
1111 * with a slot number to specify the key to use for en/decryption.
1212 *
13
- * As the number of slots are limited, and programming keys is expensive on
13
+ * As the number of slots is limited, and programming keys is expensive on
1414 * many inline encryption hardware, we don't want to program the same key into
1515 * multiple slots - if multiple requests are using the same key, we want to
1616 * program just one slot with that key and use that slot for all requests.
....@@ -22,170 +22,78 @@
2222 * and tell it how to perform device specific operations like programming/
2323 * evicting keys from keyslots.
2424 *
25
- * Upper layers will call keyslot_manager_get_slot_for_key() to program a
25
+ * Upper layers will call blk_ksm_get_slot_for_key() to program a
2626 * key into some slot in the inline encryption hardware.
2727 */
28
-#include <crypto/algapi.h>
28
+
29
+#define pr_fmt(fmt) "blk-crypto: " fmt
30
+
2931 #include <linux/keyslot-manager.h>
32
+#include <linux/device.h>
3033 #include <linux/atomic.h>
3134 #include <linux/mutex.h>
3235 #include <linux/pm_runtime.h>
3336 #include <linux/wait.h>
3437 #include <linux/blkdev.h>
3538
36
-struct keyslot {
39
+struct blk_ksm_keyslot {
3740 atomic_t slot_refs;
3841 struct list_head idle_slot_node;
3942 struct hlist_node hash_node;
40
- struct blk_crypto_key key;
43
+ const struct blk_crypto_key *key;
44
+ struct blk_keyslot_manager *ksm;
4145 };
4246
43
-struct keyslot_manager {
44
- unsigned int num_slots;
45
- struct keyslot_mgmt_ll_ops ksm_ll_ops;
46
- unsigned int features;
47
- unsigned int crypto_mode_supported[BLK_ENCRYPTION_MODE_MAX];
48
- unsigned int max_dun_bytes_supported;
49
- void *ll_priv_data;
50
-
51
-#ifdef CONFIG_PM
52
- /* Device for runtime power management (NULL if none) */
53
- struct device *dev;
54
-#endif
55
-
56
- /* Protects programming and evicting keys from the device */
57
- struct rw_semaphore lock;
58
-
59
- /* List of idle slots, with least recently used slot at front */
60
- wait_queue_head_t idle_slots_wait_queue;
61
- struct list_head idle_slots;
62
- spinlock_t idle_slots_lock;
63
-
64
- /*
65
- * Hash table which maps key hashes to keyslots, so that we can find a
66
- * key's keyslot in O(1) time rather than O(num_slots). Protected by
67
- * 'lock'. A cryptographic hash function is used so that timing attacks
68
- * can't leak information about the raw keys.
69
- */
70
- struct hlist_head *slot_hashtable;
71
- unsigned int slot_hashtable_size;
72
-
73
- /* Per-keyslot data */
74
- struct keyslot slots[];
75
-};
76
-
77
-static inline bool keyslot_manager_is_passthrough(struct keyslot_manager *ksm)
78
-{
79
- return ksm->num_slots == 0;
80
-}
81
-
82
-#ifdef CONFIG_PM
83
-static inline void keyslot_manager_set_dev(struct keyslot_manager *ksm,
84
- struct device *dev)
85
-{
86
- ksm->dev = dev;
87
-}
88
-
89
-/* If there's an underlying device and it's suspended, resume it. */
90
-static inline void keyslot_manager_pm_get(struct keyslot_manager *ksm)
91
-{
92
- if (ksm->dev)
93
- pm_runtime_get_sync(ksm->dev);
94
-}
95
-
96
-static inline void keyslot_manager_pm_put(struct keyslot_manager *ksm)
97
-{
98
- if (ksm->dev)
99
- pm_runtime_put_sync(ksm->dev);
100
-}
101
-#else /* CONFIG_PM */
102
-static inline void keyslot_manager_set_dev(struct keyslot_manager *ksm,
103
- struct device *dev)
104
-{
105
-}
106
-
107
-static inline void keyslot_manager_pm_get(struct keyslot_manager *ksm)
108
-{
109
-}
110
-
111
-static inline void keyslot_manager_pm_put(struct keyslot_manager *ksm)
112
-{
113
-}
114
-#endif /* !CONFIG_PM */
115
-
116
-static inline void keyslot_manager_hw_enter(struct keyslot_manager *ksm)
47
+static inline void blk_ksm_hw_enter(struct blk_keyslot_manager *ksm)
11748 {
11849 /*
11950 * Calling into the driver requires ksm->lock held and the device
12051 * resumed. But we must resume the device first, since that can acquire
121
- * and release ksm->lock via keyslot_manager_reprogram_all_keys().
52
+ * and release ksm->lock via blk_ksm_reprogram_all_keys().
12253 */
123
- keyslot_manager_pm_get(ksm);
54
+ if (ksm->dev)
55
+ pm_runtime_get_sync(ksm->dev);
12456 down_write(&ksm->lock);
12557 }
12658
127
-static inline void keyslot_manager_hw_exit(struct keyslot_manager *ksm)
59
+static inline void blk_ksm_hw_exit(struct blk_keyslot_manager *ksm)
12860 {
12961 up_write(&ksm->lock);
130
- keyslot_manager_pm_put(ksm);
62
+ if (ksm->dev)
63
+ pm_runtime_put_sync(ksm->dev);
64
+}
65
+
66
+static inline bool blk_ksm_is_passthrough(struct blk_keyslot_manager *ksm)
67
+{
68
+ return ksm->num_slots == 0;
13169 }
13270
13371 /**
134
- * keyslot_manager_create() - Create a keyslot manager
135
- * @dev: Device for runtime power management (NULL if none)
72
+ * blk_ksm_init() - Initialize a keyslot manager
73
+ * @ksm: The keyslot_manager to initialize.
13674 * @num_slots: The number of key slots to manage.
137
- * @ksm_ll_ops: The struct keyslot_mgmt_ll_ops for the device that this keyslot
138
- * manager will use to perform operations like programming and
139
- * evicting keys.
140
- * @features: The supported features as a bitmask of BLK_CRYPTO_FEATURE_* flags.
141
- * Most drivers should set BLK_CRYPTO_FEATURE_STANDARD_KEYS here.
142
- * @crypto_mode_supported: Array of size BLK_ENCRYPTION_MODE_MAX of
143
- * bitmasks that represents whether a crypto mode
144
- * and data unit size are supported. The i'th bit
145
- * of crypto_mode_supported[crypto_mode] is set iff
146
- * a data unit size of (1 << i) is supported. We
147
- * only support data unit sizes that are powers of
148
- * 2.
149
- * @ll_priv_data: Private data passed as is to the functions in ksm_ll_ops.
15075 *
151
- * Allocate memory for and initialize a keyslot manager. Called by e.g.
152
- * storage drivers to set up a keyslot manager in their request_queue.
76
+ * Allocate memory for keyslots and initialize a keyslot manager. Called by
77
+ * e.g. storage drivers to set up a keyslot manager in their request_queue.
15378 *
154
- * Context: May sleep
155
- * Return: Pointer to constructed keyslot manager or NULL on error.
79
+ * Return: 0 on success, or else a negative error code.
15680 */
157
-struct keyslot_manager *keyslot_manager_create(
158
- struct device *dev,
159
- unsigned int num_slots,
160
- const struct keyslot_mgmt_ll_ops *ksm_ll_ops,
161
- unsigned int features,
162
- const unsigned int crypto_mode_supported[BLK_ENCRYPTION_MODE_MAX],
163
- void *ll_priv_data)
81
+int blk_ksm_init(struct blk_keyslot_manager *ksm, unsigned int num_slots)
16482 {
165
- struct keyslot_manager *ksm;
16683 unsigned int slot;
16784 unsigned int i;
85
+ unsigned int slot_hashtable_size;
86
+
87
+ memset(ksm, 0, sizeof(*ksm));
16888
16989 if (num_slots == 0)
170
- return NULL;
90
+ return -EINVAL;
17191
172
- /* Check that all ops are specified */
173
- if (ksm_ll_ops->keyslot_program == NULL ||
174
- ksm_ll_ops->keyslot_evict == NULL)
175
- return NULL;
176
-
177
- ksm = kvzalloc(struct_size(ksm, slots, num_slots), GFP_KERNEL);
178
- if (!ksm)
179
- return NULL;
92
+ ksm->slots = kvcalloc(num_slots, sizeof(ksm->slots[0]), GFP_KERNEL);
93
+ if (!ksm->slots)
94
+ return -ENOMEM;
18095
18196 ksm->num_slots = num_slots;
182
- ksm->ksm_ll_ops = *ksm_ll_ops;
183
- ksm->features = features;
184
- memcpy(ksm->crypto_mode_supported, crypto_mode_supported,
185
- sizeof(ksm->crypto_mode_supported));
186
- ksm->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
187
- ksm->ll_priv_data = ll_priv_data;
188
- keyslot_manager_set_dev(ksm, dev);
18997
19098 init_rwsem(&ksm->lock);
19199
....@@ -193,120 +101,160 @@
193101 INIT_LIST_HEAD(&ksm->idle_slots);
194102
195103 for (slot = 0; slot < num_slots; slot++) {
104
+ ksm->slots[slot].ksm = ksm;
196105 list_add_tail(&ksm->slots[slot].idle_slot_node,
197106 &ksm->idle_slots);
198107 }
199108
200109 spin_lock_init(&ksm->idle_slots_lock);
201110
202
- ksm->slot_hashtable_size = roundup_pow_of_two(num_slots);
203
- ksm->slot_hashtable = kvmalloc_array(ksm->slot_hashtable_size,
111
+ slot_hashtable_size = roundup_pow_of_two(num_slots);
112
+ /*
113
+ * hash_ptr() assumes bits != 0, so ensure the hash table has at least 2
114
+ * buckets. This only makes a difference when there is only 1 keyslot.
115
+ */
116
+ if (slot_hashtable_size < 2)
117
+ slot_hashtable_size = 2;
118
+
119
+ ksm->log_slot_ht_size = ilog2(slot_hashtable_size);
120
+ ksm->slot_hashtable = kvmalloc_array(slot_hashtable_size,
204121 sizeof(ksm->slot_hashtable[0]),
205122 GFP_KERNEL);
206123 if (!ksm->slot_hashtable)
207
- goto err_free_ksm;
208
- for (i = 0; i < ksm->slot_hashtable_size; i++)
124
+ goto err_destroy_ksm;
125
+ for (i = 0; i < slot_hashtable_size; i++)
209126 INIT_HLIST_HEAD(&ksm->slot_hashtable[i]);
210127
211
- return ksm;
128
+ return 0;
212129
213
-err_free_ksm:
214
- keyslot_manager_destroy(ksm);
215
- return NULL;
130
+err_destroy_ksm:
131
+ blk_ksm_destroy(ksm);
132
+ return -ENOMEM;
216133 }
217
-EXPORT_SYMBOL_GPL(keyslot_manager_create);
134
+EXPORT_SYMBOL_GPL(blk_ksm_init);
218135
219
-void keyslot_manager_set_max_dun_bytes(struct keyslot_manager *ksm,
220
- unsigned int max_dun_bytes)
136
+static void blk_ksm_destroy_callback(void *ksm)
221137 {
222
- ksm->max_dun_bytes_supported = max_dun_bytes;
138
+ blk_ksm_destroy(ksm);
223139 }
224
-EXPORT_SYMBOL_GPL(keyslot_manager_set_max_dun_bytes);
140
+
141
+/**
142
+ * devm_blk_ksm_init() - Resource-managed blk_ksm_init()
143
+ * @dev: The device which owns the blk_keyslot_manager.
144
+ * @ksm: The blk_keyslot_manager to initialize.
145
+ * @num_slots: The number of key slots to manage.
146
+ *
147
+ * Like blk_ksm_init(), but causes blk_ksm_destroy() to be called automatically
148
+ * on driver detach.
149
+ *
150
+ * Return: 0 on success, or else a negative error code.
151
+ */
152
+int devm_blk_ksm_init(struct device *dev, struct blk_keyslot_manager *ksm,
153
+ unsigned int num_slots)
154
+{
155
+ int err = blk_ksm_init(ksm, num_slots);
156
+
157
+ if (err)
158
+ return err;
159
+
160
+ return devm_add_action_or_reset(dev, blk_ksm_destroy_callback, ksm);
161
+}
162
+EXPORT_SYMBOL_GPL(devm_blk_ksm_init);
225163
226164 static inline struct hlist_head *
227
-hash_bucket_for_key(struct keyslot_manager *ksm,
228
- const struct blk_crypto_key *key)
165
+blk_ksm_hash_bucket_for_key(struct blk_keyslot_manager *ksm,
166
+ const struct blk_crypto_key *key)
229167 {
230
- return &ksm->slot_hashtable[blk_crypto_key_hash(key) &
231
- (ksm->slot_hashtable_size - 1)];
168
+ return &ksm->slot_hashtable[hash_ptr(key, ksm->log_slot_ht_size)];
232169 }
233170
234
-static void remove_slot_from_lru_list(struct keyslot_manager *ksm, int slot)
171
+static void blk_ksm_remove_slot_from_lru_list(struct blk_ksm_keyslot *slot)
235172 {
173
+ struct blk_keyslot_manager *ksm = slot->ksm;
236174 unsigned long flags;
237175
238176 spin_lock_irqsave(&ksm->idle_slots_lock, flags);
239
- list_del(&ksm->slots[slot].idle_slot_node);
177
+ list_del(&slot->idle_slot_node);
240178 spin_unlock_irqrestore(&ksm->idle_slots_lock, flags);
241179 }
242180
243
-static int find_keyslot(struct keyslot_manager *ksm,
244
- const struct blk_crypto_key *key)
181
+static struct blk_ksm_keyslot *blk_ksm_find_keyslot(
182
+ struct blk_keyslot_manager *ksm,
183
+ const struct blk_crypto_key *key)
245184 {
246
- const struct hlist_head *head = hash_bucket_for_key(ksm, key);
247
- const struct keyslot *slotp;
185
+ const struct hlist_head *head = blk_ksm_hash_bucket_for_key(ksm, key);
186
+ struct blk_ksm_keyslot *slotp;
248187
249188 hlist_for_each_entry(slotp, head, hash_node) {
250
- if (slotp->key.hash == key->hash &&
251
- slotp->key.crypto_mode == key->crypto_mode &&
252
- slotp->key.size == key->size &&
253
- slotp->key.data_unit_size == key->data_unit_size &&
254
- !crypto_memneq(slotp->key.raw, key->raw, key->size))
255
- return slotp - ksm->slots;
189
+ if (slotp->key == key)
190
+ return slotp;
256191 }
257
- return -ENOKEY;
192
+ return NULL;
258193 }
259194
260
-static int find_and_grab_keyslot(struct keyslot_manager *ksm,
261
- const struct blk_crypto_key *key)
195
+static struct blk_ksm_keyslot *blk_ksm_find_and_grab_keyslot(
196
+ struct blk_keyslot_manager *ksm,
197
+ const struct blk_crypto_key *key)
262198 {
263
- int slot;
199
+ struct blk_ksm_keyslot *slot;
264200
265
- slot = find_keyslot(ksm, key);
266
- if (slot < 0)
267
- return slot;
268
- if (atomic_inc_return(&ksm->slots[slot].slot_refs) == 1) {
201
+ slot = blk_ksm_find_keyslot(ksm, key);
202
+ if (!slot)
203
+ return NULL;
204
+ if (atomic_inc_return(&slot->slot_refs) == 1) {
269205 /* Took first reference to this slot; remove it from LRU list */
270
- remove_slot_from_lru_list(ksm, slot);
206
+ blk_ksm_remove_slot_from_lru_list(slot);
271207 }
272208 return slot;
273209 }
274210
211
+unsigned int blk_ksm_get_slot_idx(struct blk_ksm_keyslot *slot)
212
+{
213
+ return slot - slot->ksm->slots;
214
+}
215
+EXPORT_SYMBOL_GPL(blk_ksm_get_slot_idx);
216
+
275217 /**
276
- * keyslot_manager_get_slot_for_key() - Program a key into a keyslot.
218
+ * blk_ksm_get_slot_for_key() - Program a key into a keyslot.
277219 * @ksm: The keyslot manager to program the key into.
278220 * @key: Pointer to the key object to program, including the raw key, crypto
279221 * mode, and data unit size.
222
+ * @slot_ptr: A pointer to return the pointer of the allocated keyslot.
280223 *
281224 * Get a keyslot that's been programmed with the specified key. If one already
282225 * exists, return it with incremented refcount. Otherwise, wait for a keyslot
283226 * to become idle and program it.
284227 *
285228 * Context: Process context. Takes and releases ksm->lock.
286
- * Return: The keyslot on success, else a -errno value.
229
+ * Return: BLK_STS_OK on success (and keyslot is set to the pointer of the
230
+ * allocated keyslot), or some other blk_status_t otherwise (and
231
+ * keyslot is set to NULL).
287232 */
288
-int keyslot_manager_get_slot_for_key(struct keyslot_manager *ksm,
289
- const struct blk_crypto_key *key)
233
+blk_status_t blk_ksm_get_slot_for_key(struct blk_keyslot_manager *ksm,
234
+ const struct blk_crypto_key *key,
235
+ struct blk_ksm_keyslot **slot_ptr)
290236 {
291
- int slot;
237
+ struct blk_ksm_keyslot *slot;
238
+ int slot_idx;
292239 int err;
293
- struct keyslot *idle_slot;
294240
295
- if (keyslot_manager_is_passthrough(ksm))
296
- return 0;
241
+ *slot_ptr = NULL;
242
+
243
+ if (blk_ksm_is_passthrough(ksm))
244
+ return BLK_STS_OK;
297245
298246 down_read(&ksm->lock);
299
- slot = find_and_grab_keyslot(ksm, key);
247
+ slot = blk_ksm_find_and_grab_keyslot(ksm, key);
300248 up_read(&ksm->lock);
301
- if (slot != -ENOKEY)
302
- return slot;
249
+ if (slot)
250
+ goto success;
303251
304252 for (;;) {
305
- keyslot_manager_hw_enter(ksm);
306
- slot = find_and_grab_keyslot(ksm, key);
307
- if (slot != -ENOKEY) {
308
- keyslot_manager_hw_exit(ksm);
309
- return slot;
253
+ blk_ksm_hw_enter(ksm);
254
+ slot = blk_ksm_find_and_grab_keyslot(ksm, key);
255
+ if (slot) {
256
+ blk_ksm_hw_exit(ksm);
257
+ goto success;
310258 }
311259
312260 /*
....@@ -316,182 +264,146 @@
316264 if (!list_empty(&ksm->idle_slots))
317265 break;
318266
319
- keyslot_manager_hw_exit(ksm);
267
+ blk_ksm_hw_exit(ksm);
320268 wait_event(ksm->idle_slots_wait_queue,
321269 !list_empty(&ksm->idle_slots));
322270 }
323271
324
- idle_slot = list_first_entry(&ksm->idle_slots, struct keyslot,
325
- idle_slot_node);
326
- slot = idle_slot - ksm->slots;
272
+ slot = list_first_entry(&ksm->idle_slots, struct blk_ksm_keyslot,
273
+ idle_slot_node);
274
+ slot_idx = blk_ksm_get_slot_idx(slot);
327275
328
- err = ksm->ksm_ll_ops.keyslot_program(ksm, key, slot);
276
+ err = ksm->ksm_ll_ops.keyslot_program(ksm, key, slot_idx);
329277 if (err) {
330278 wake_up(&ksm->idle_slots_wait_queue);
331
- keyslot_manager_hw_exit(ksm);
332
- return err;
279
+ blk_ksm_hw_exit(ksm);
280
+ return errno_to_blk_status(err);
333281 }
334282
335283 /* Move this slot to the hash list for the new key. */
336
- if (idle_slot->key.crypto_mode != BLK_ENCRYPTION_MODE_INVALID)
337
- hlist_del(&idle_slot->hash_node);
338
- hlist_add_head(&idle_slot->hash_node, hash_bucket_for_key(ksm, key));
284
+ if (slot->key)
285
+ hlist_del(&slot->hash_node);
286
+ slot->key = key;
287
+ hlist_add_head(&slot->hash_node, blk_ksm_hash_bucket_for_key(ksm, key));
339288
340
- atomic_set(&idle_slot->slot_refs, 1);
341
- idle_slot->key = *key;
289
+ atomic_set(&slot->slot_refs, 1);
342290
343
- remove_slot_from_lru_list(ksm, slot);
291
+ blk_ksm_remove_slot_from_lru_list(slot);
344292
345
- keyslot_manager_hw_exit(ksm);
346
- return slot;
293
+ blk_ksm_hw_exit(ksm);
294
+success:
295
+ *slot_ptr = slot;
296
+ return BLK_STS_OK;
347297 }
348298
349299 /**
350
- * keyslot_manager_get_slot() - Increment the refcount on the specified slot.
351
- * @ksm: The keyslot manager that we want to modify.
352
- * @slot: The slot to increment the refcount of.
353
- *
354
- * This function assumes that there is already an active reference to that slot
355
- * and simply increments the refcount. This is useful when cloning a bio that
356
- * already has a reference to a keyslot, and we want the cloned bio to also have
357
- * its own reference.
300
+ * blk_ksm_put_slot() - Release a reference to a slot
301
+ * @slot: The keyslot to release the reference of.
358302 *
359303 * Context: Any context.
360304 */
361
-void keyslot_manager_get_slot(struct keyslot_manager *ksm, unsigned int slot)
305
+void blk_ksm_put_slot(struct blk_ksm_keyslot *slot)
362306 {
363
- if (keyslot_manager_is_passthrough(ksm))
364
- return;
365
-
366
- if (WARN_ON(slot >= ksm->num_slots))
367
- return;
368
-
369
- WARN_ON(atomic_inc_return(&ksm->slots[slot].slot_refs) < 2);
370
-}
371
-
372
-/**
373
- * keyslot_manager_put_slot() - Release a reference to a slot
374
- * @ksm: The keyslot manager to release the reference from.
375
- * @slot: The slot to release the reference from.
376
- *
377
- * Context: Any context.
378
- */
379
-void keyslot_manager_put_slot(struct keyslot_manager *ksm, unsigned int slot)
380
-{
307
+ struct blk_keyslot_manager *ksm;
381308 unsigned long flags;
382309
383
- if (keyslot_manager_is_passthrough(ksm))
310
+ if (!slot)
384311 return;
385312
386
- if (WARN_ON(slot >= ksm->num_slots))
387
- return;
313
+ ksm = slot->ksm;
388314
389
- if (atomic_dec_and_lock_irqsave(&ksm->slots[slot].slot_refs,
315
+ if (atomic_dec_and_lock_irqsave(&slot->slot_refs,
390316 &ksm->idle_slots_lock, flags)) {
391
- list_add_tail(&ksm->slots[slot].idle_slot_node,
392
- &ksm->idle_slots);
317
+ list_add_tail(&slot->idle_slot_node, &ksm->idle_slots);
393318 spin_unlock_irqrestore(&ksm->idle_slots_lock, flags);
394319 wake_up(&ksm->idle_slots_wait_queue);
395320 }
396321 }
397322
398323 /**
399
- * keyslot_manager_crypto_mode_supported() - Find out if a crypto_mode /
400
- * data unit size / is_hw_wrapped_key
401
- * combination is supported by a ksm.
324
+ * blk_ksm_crypto_cfg_supported() - Find out if a crypto configuration is
325
+ * supported by a ksm.
402326 * @ksm: The keyslot manager to check
403
- * @crypto_mode: The crypto mode to check for.
404
- * @dun_bytes: The number of bytes that will be used to specify the DUN
405
- * @data_unit_size: The data_unit_size for the mode.
406
- * @is_hw_wrapped_key: Whether a hardware-wrapped key will be used.
327
+ * @cfg: The crypto configuration to check for.
407328 *
408
- * Calls and returns the result of the crypto_mode_supported function specified
409
- * by the ksm.
329
+ * Checks for crypto_mode/data unit size/dun bytes support.
410330 *
411
- * Context: Process context.
412
- * Return: Whether or not this ksm supports the specified crypto settings.
331
+ * Return: Whether or not this ksm supports the specified crypto config.
413332 */
414
-bool keyslot_manager_crypto_mode_supported(struct keyslot_manager *ksm,
415
- enum blk_crypto_mode_num crypto_mode,
416
- unsigned int dun_bytes,
417
- unsigned int data_unit_size,
418
- bool is_hw_wrapped_key)
333
+bool blk_ksm_crypto_cfg_supported(struct blk_keyslot_manager *ksm,
334
+ const struct blk_crypto_config *cfg)
419335 {
420336 if (!ksm)
421337 return false;
422
- if (WARN_ON(crypto_mode >= BLK_ENCRYPTION_MODE_MAX))
338
+ if (!(ksm->crypto_modes_supported[cfg->crypto_mode] &
339
+ cfg->data_unit_size))
423340 return false;
424
- if (WARN_ON(!is_power_of_2(data_unit_size)))
341
+ if (ksm->max_dun_bytes_supported < cfg->dun_bytes)
425342 return false;
426
- if (is_hw_wrapped_key) {
343
+ if (cfg->is_hw_wrapped) {
427344 if (!(ksm->features & BLK_CRYPTO_FEATURE_WRAPPED_KEYS))
428345 return false;
429346 } else {
430347 if (!(ksm->features & BLK_CRYPTO_FEATURE_STANDARD_KEYS))
431348 return false;
432349 }
433
- if (!(ksm->crypto_mode_supported[crypto_mode] & data_unit_size))
434
- return false;
435
-
436
- return ksm->max_dun_bytes_supported >= dun_bytes;
350
+ return true;
437351 }
438352
439353 /**
440
- * keyslot_manager_evict_key() - Evict a key from the lower layer device.
354
+ * blk_ksm_evict_key() - Evict a key from the lower layer device.
441355 * @ksm: The keyslot manager to evict from
442356 * @key: The key to evict
443357 *
444358 * Find the keyslot that the specified key was programmed into, and evict that
445
- * slot from the lower layer device if that slot is not currently in use.
359
+ * slot from the lower layer device. The slot must not be in use by any
360
+ * in-flight IO when this function is called.
446361 *
447362 * Context: Process context. Takes and releases ksm->lock.
448
- * Return: 0 on success, -EBUSY if the key is still in use, or another
449
- * -errno value on other error.
363
+ * Return: 0 on success or if there's no keyslot with the specified key, -EBUSY
364
+ * if the keyslot is still in use, or another -errno value on other
365
+ * error.
450366 */
451
-int keyslot_manager_evict_key(struct keyslot_manager *ksm,
452
- const struct blk_crypto_key *key)
367
+int blk_ksm_evict_key(struct blk_keyslot_manager *ksm,
368
+ const struct blk_crypto_key *key)
453369 {
454
- int slot;
455
- int err;
456
- struct keyslot *slotp;
370
+ struct blk_ksm_keyslot *slot;
371
+ int err = 0;
457372
458
- if (keyslot_manager_is_passthrough(ksm)) {
373
+ if (blk_ksm_is_passthrough(ksm)) {
459374 if (ksm->ksm_ll_ops.keyslot_evict) {
460
- keyslot_manager_hw_enter(ksm);
375
+ blk_ksm_hw_enter(ksm);
461376 err = ksm->ksm_ll_ops.keyslot_evict(ksm, key, -1);
462
- keyslot_manager_hw_exit(ksm);
377
+ blk_ksm_hw_exit(ksm);
463378 return err;
464379 }
465380 return 0;
466381 }
467382
468
- keyslot_manager_hw_enter(ksm);
469
-
470
- slot = find_keyslot(ksm, key);
471
- if (slot < 0) {
472
- err = slot;
383
+ blk_ksm_hw_enter(ksm);
384
+ slot = blk_ksm_find_keyslot(ksm, key);
385
+ if (!slot)
473386 goto out_unlock;
474
- }
475
- slotp = &ksm->slots[slot];
476387
477
- if (atomic_read(&slotp->slot_refs) != 0) {
388
+ if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) {
478389 err = -EBUSY;
479390 goto out_unlock;
480391 }
481
- err = ksm->ksm_ll_ops.keyslot_evict(ksm, key, slot);
392
+ err = ksm->ksm_ll_ops.keyslot_evict(ksm, key,
393
+ blk_ksm_get_slot_idx(slot));
482394 if (err)
483395 goto out_unlock;
484396
485
- hlist_del(&slotp->hash_node);
486
- memzero_explicit(&slotp->key, sizeof(slotp->key));
397
+ hlist_del(&slot->hash_node);
398
+ slot->key = NULL;
487399 err = 0;
488400 out_unlock:
489
- keyslot_manager_hw_exit(ksm);
401
+ blk_ksm_hw_exit(ksm);
490402 return err;
491403 }
492404
493405 /**
494
- * keyslot_manager_reprogram_all_keys() - Re-program all keyslots.
406
+ * blk_ksm_reprogram_all_keys() - Re-program all keyslots.
495407 * @ksm: The keyslot manager
496408 *
497409 * Re-program all keyslots that are supposed to have a key programmed. This is
....@@ -499,133 +411,57 @@
499411 *
500412 * Context: Process context. Takes and releases ksm->lock.
501413 */
502
-void keyslot_manager_reprogram_all_keys(struct keyslot_manager *ksm)
414
+void blk_ksm_reprogram_all_keys(struct blk_keyslot_manager *ksm)
503415 {
504416 unsigned int slot;
505417
506
- if (WARN_ON(keyslot_manager_is_passthrough(ksm)))
418
+ if (blk_ksm_is_passthrough(ksm))
507419 return;
508420
509421 /* This is for device initialization, so don't resume the device */
510422 down_write(&ksm->lock);
511423 for (slot = 0; slot < ksm->num_slots; slot++) {
512
- const struct keyslot *slotp = &ksm->slots[slot];
424
+ const struct blk_crypto_key *key = ksm->slots[slot].key;
513425 int err;
514426
515
- if (slotp->key.crypto_mode == BLK_ENCRYPTION_MODE_INVALID)
427
+ if (!key)
516428 continue;
517429
518
- err = ksm->ksm_ll_ops.keyslot_program(ksm, &slotp->key, slot);
430
+ err = ksm->ksm_ll_ops.keyslot_program(ksm, key, slot);
519431 WARN_ON(err);
520432 }
521433 up_write(&ksm->lock);
522434 }
523
-EXPORT_SYMBOL_GPL(keyslot_manager_reprogram_all_keys);
435
+EXPORT_SYMBOL_GPL(blk_ksm_reprogram_all_keys);
524436
525
-/**
526
- * keyslot_manager_private() - return the private data stored with ksm
527
- * @ksm: The keyslot manager
528
- *
529
- * Returns the private data passed to the ksm when it was created.
530
- */
531
-void *keyslot_manager_private(struct keyslot_manager *ksm)
437
+void blk_ksm_destroy(struct blk_keyslot_manager *ksm)
532438 {
533
- return ksm->ll_priv_data;
534
-}
535
-EXPORT_SYMBOL_GPL(keyslot_manager_private);
536
-
537
-void keyslot_manager_destroy(struct keyslot_manager *ksm)
538
-{
539
- if (ksm) {
540
- kvfree(ksm->slot_hashtable);
541
- memzero_explicit(ksm, struct_size(ksm, slots, ksm->num_slots));
542
- kvfree(ksm);
543
- }
544
-}
545
-EXPORT_SYMBOL_GPL(keyslot_manager_destroy);
546
-
547
-/**
548
- * keyslot_manager_create_passthrough() - Create a passthrough keyslot manager
549
- * @dev: Device for runtime power management (NULL if none)
550
- * @ksm_ll_ops: The struct keyslot_mgmt_ll_ops
551
- * @features: Bitmask of BLK_CRYPTO_FEATURE_* flags
552
- * @crypto_mode_supported: Bitmasks for supported encryption modes
553
- * @ll_priv_data: Private data passed as is to the functions in ksm_ll_ops.
554
- *
555
- * Allocate memory for and initialize a passthrough keyslot manager.
556
- * Called by e.g. storage drivers to set up a keyslot manager in their
557
- * request_queue, when the storage driver wants to manage its keys by itself.
558
- * This is useful for inline encryption hardware that don't have a small fixed
559
- * number of keyslots, and for layered devices.
560
- *
561
- * See keyslot_manager_create() for more details about the parameters.
562
- *
563
- * Context: This function may sleep
564
- * Return: Pointer to constructed keyslot manager or NULL on error.
565
- */
566
-struct keyslot_manager *keyslot_manager_create_passthrough(
567
- struct device *dev,
568
- const struct keyslot_mgmt_ll_ops *ksm_ll_ops,
569
- unsigned int features,
570
- const unsigned int crypto_mode_supported[BLK_ENCRYPTION_MODE_MAX],
571
- void *ll_priv_data)
572
-{
573
- struct keyslot_manager *ksm;
574
-
575
- ksm = kzalloc(sizeof(*ksm), GFP_KERNEL);
576439 if (!ksm)
577
- return NULL;
578
-
579
- ksm->ksm_ll_ops = *ksm_ll_ops;
580
- ksm->features = features;
581
- memcpy(ksm->crypto_mode_supported, crypto_mode_supported,
582
- sizeof(ksm->crypto_mode_supported));
583
- ksm->max_dun_bytes_supported = BLK_CRYPTO_MAX_IV_SIZE;
584
- ksm->ll_priv_data = ll_priv_data;
585
- keyslot_manager_set_dev(ksm, dev);
586
-
587
- init_rwsem(&ksm->lock);
588
-
589
- return ksm;
440
+ return;
441
+ kvfree(ksm->slot_hashtable);
442
+ kvfree_sensitive(ksm->slots, sizeof(ksm->slots[0]) * ksm->num_slots);
443
+ memzero_explicit(ksm, sizeof(*ksm));
590444 }
591
-EXPORT_SYMBOL_GPL(keyslot_manager_create_passthrough);
445
+EXPORT_SYMBOL_GPL(blk_ksm_destroy);
592446
593
-/**
594
- * keyslot_manager_intersect_modes() - restrict supported modes by child device
595
- * @parent: The keyslot manager for parent device
596
- * @child: The keyslot manager for child device, or NULL
597
- *
598
- * Clear any crypto mode support bits in @parent that aren't set in @child.
599
- * If @child is NULL, then all parent bits are cleared.
600
- *
601
- * Only use this when setting up the keyslot manager for a layered device,
602
- * before it's been exposed yet.
603
- */
604
-void keyslot_manager_intersect_modes(struct keyslot_manager *parent,
605
- const struct keyslot_manager *child)
447
+bool blk_ksm_register(struct blk_keyslot_manager *ksm, struct request_queue *q)
606448 {
607
- if (child) {
608
- unsigned int i;
609
-
610
- parent->features &= child->features;
611
- parent->max_dun_bytes_supported =
612
- min(parent->max_dun_bytes_supported,
613
- child->max_dun_bytes_supported);
614
- for (i = 0; i < ARRAY_SIZE(child->crypto_mode_supported); i++) {
615
- parent->crypto_mode_supported[i] &=
616
- child->crypto_mode_supported[i];
617
- }
618
- } else {
619
- parent->features = 0;
620
- parent->max_dun_bytes_supported = 0;
621
- memset(parent->crypto_mode_supported, 0,
622
- sizeof(parent->crypto_mode_supported));
449
+ if (blk_integrity_queue_supports_integrity(q)) {
450
+ pr_warn("Integrity and hardware inline encryption are not supported together. Disabling hardware inline encryption.\n");
451
+ return false;
623452 }
453
+ q->ksm = ksm;
454
+ return true;
624455 }
625
-EXPORT_SYMBOL_GPL(keyslot_manager_intersect_modes);
456
+EXPORT_SYMBOL_GPL(blk_ksm_register);
457
+
458
+void blk_ksm_unregister(struct request_queue *q)
459
+{
460
+ q->ksm = NULL;
461
+}
626462
627463 /**
628
- * keyslot_manager_derive_raw_secret() - Derive software secret from wrapped key
464
+ * blk_ksm_derive_raw_secret() - Derive software secret from wrapped key
629465 * @ksm: The keyslot manager
630466 * @wrapped_key: The wrapped key
631467 * @wrapped_key_size: Size of the wrapped key in bytes
....@@ -641,23 +477,154 @@
641477 * Return: 0 on success, -EOPNOTSUPP if hardware-wrapped keys are unsupported,
642478 * or another -errno code.
643479 */
644
-int keyslot_manager_derive_raw_secret(struct keyslot_manager *ksm,
645
- const u8 *wrapped_key,
646
- unsigned int wrapped_key_size,
647
- u8 *secret, unsigned int secret_size)
480
+int blk_ksm_derive_raw_secret(struct blk_keyslot_manager *ksm,
481
+ const u8 *wrapped_key,
482
+ unsigned int wrapped_key_size,
483
+ u8 *secret, unsigned int secret_size)
648484 {
649485 int err;
650486
651487 if (ksm->ksm_ll_ops.derive_raw_secret) {
652
- keyslot_manager_hw_enter(ksm);
488
+ blk_ksm_hw_enter(ksm);
653489 err = ksm->ksm_ll_ops.derive_raw_secret(ksm, wrapped_key,
654490 wrapped_key_size,
655491 secret, secret_size);
656
- keyslot_manager_hw_exit(ksm);
492
+ blk_ksm_hw_exit(ksm);
657493 } else {
658494 err = -EOPNOTSUPP;
659495 }
660496
661497 return err;
662498 }
663
-EXPORT_SYMBOL_GPL(keyslot_manager_derive_raw_secret);
499
+EXPORT_SYMBOL_GPL(blk_ksm_derive_raw_secret);
500
+
501
+/**
502
+ * blk_ksm_intersect_modes() - restrict supported modes by child device
503
+ * @parent: The keyslot manager for parent device
504
+ * @child: The keyslot manager for child device, or NULL
505
+ *
506
+ * Clear any crypto mode support bits in @parent that aren't set in @child.
507
+ * If @child is NULL, then all parent bits are cleared.
508
+ *
509
+ * Only use this when setting up the keyslot manager for a layered device,
510
+ * before it's been exposed yet.
511
+ */
512
+void blk_ksm_intersect_modes(struct blk_keyslot_manager *parent,
513
+ const struct blk_keyslot_manager *child)
514
+{
515
+ if (child) {
516
+ unsigned int i;
517
+
518
+ parent->max_dun_bytes_supported =
519
+ min(parent->max_dun_bytes_supported,
520
+ child->max_dun_bytes_supported);
521
+ for (i = 0; i < ARRAY_SIZE(child->crypto_modes_supported);
522
+ i++) {
523
+ parent->crypto_modes_supported[i] &=
524
+ child->crypto_modes_supported[i];
525
+ }
526
+ parent->features &= child->features;
527
+ } else {
528
+ parent->max_dun_bytes_supported = 0;
529
+ memset(parent->crypto_modes_supported, 0,
530
+ sizeof(parent->crypto_modes_supported));
531
+ parent->features = 0;
532
+ }
533
+}
534
+EXPORT_SYMBOL_GPL(blk_ksm_intersect_modes);
535
+
536
+/**
537
+ * blk_ksm_is_superset() - Check if a KSM supports a superset of crypto modes
538
+ * and DUN bytes that another KSM supports. Here,
539
+ * "superset" refers to the mathematical meaning of the
540
+ * word - i.e. if two KSMs have the *same* capabilities,
541
+ * they *are* considered supersets of each other.
542
+ * @ksm_superset: The KSM that we want to verify is a superset
543
+ * @ksm_subset: The KSM that we want to verify is a subset
544
+ *
545
+ * Return: True if @ksm_superset supports a superset of the crypto modes and DUN
546
+ * bytes that @ksm_subset supports.
547
+ */
548
+bool blk_ksm_is_superset(struct blk_keyslot_manager *ksm_superset,
549
+ struct blk_keyslot_manager *ksm_subset)
550
+{
551
+ int i;
552
+
553
+ if (!ksm_subset)
554
+ return true;
555
+
556
+ if (!ksm_superset)
557
+ return false;
558
+
559
+ for (i = 0; i < ARRAY_SIZE(ksm_superset->crypto_modes_supported); i++) {
560
+ if (ksm_subset->crypto_modes_supported[i] &
561
+ (~ksm_superset->crypto_modes_supported[i])) {
562
+ return false;
563
+ }
564
+ }
565
+
566
+ if (ksm_subset->max_dun_bytes_supported >
567
+ ksm_superset->max_dun_bytes_supported) {
568
+ return false;
569
+ }
570
+
571
+ if (ksm_subset->features & ~ksm_superset->features)
572
+ return false;
573
+
574
+ return true;
575
+}
576
+EXPORT_SYMBOL_GPL(blk_ksm_is_superset);
577
+
578
+/**
579
+ * blk_ksm_update_capabilities() - Update the restrictions of a KSM to those of
580
+ * another KSM
581
+ * @target_ksm: The KSM whose restrictions to update.
582
+ * @reference_ksm: The KSM to whose restrictions this function will update
583
+ * @target_ksm's restrictions to.
584
+ *
585
+ * Blk-crypto requires that crypto capabilities that were
586
+ * advertised when a bio was created continue to be supported by the
587
+ * device until that bio is ended. This is turn means that a device cannot
588
+ * shrink its advertised crypto capabilities without any explicit
589
+ * synchronization with upper layers. So if there's no such explicit
590
+ * synchronization, @reference_ksm must support all the crypto capabilities that
591
+ * @target_ksm does
592
+ * (i.e. we need blk_ksm_is_superset(@reference_ksm, @target_ksm) == true).
593
+ *
594
+ * Note also that as long as the crypto capabilities are being expanded, the
595
+ * order of updates becoming visible is not important because it's alright
596
+ * for blk-crypto to see stale values - they only cause blk-crypto to
597
+ * believe that a crypto capability isn't supported when it actually is (which
598
+ * might result in blk-crypto-fallback being used if available, or the bio being
599
+ * failed).
600
+ */
601
+void blk_ksm_update_capabilities(struct blk_keyslot_manager *target_ksm,
602
+ struct blk_keyslot_manager *reference_ksm)
603
+{
604
+ memcpy(target_ksm->crypto_modes_supported,
605
+ reference_ksm->crypto_modes_supported,
606
+ sizeof(target_ksm->crypto_modes_supported));
607
+
608
+ target_ksm->max_dun_bytes_supported =
609
+ reference_ksm->max_dun_bytes_supported;
610
+
611
+ target_ksm->features = reference_ksm->features;
612
+}
613
+EXPORT_SYMBOL_GPL(blk_ksm_update_capabilities);
614
+
615
+/**
616
+ * blk_ksm_init_passthrough() - Init a passthrough keyslot manager
617
+ * @ksm: The keyslot manager to init
618
+ *
619
+ * Initialize a passthrough keyslot manager.
620
+ * Called by e.g. storage drivers to set up a keyslot manager in their
621
+ * request_queue, when the storage driver wants to manage its keys by itself.
622
+ * This is useful for inline encryption hardware that doesn't have the concept
623
+ * of keyslots, and for layered devices.
624
+ */
625
+void blk_ksm_init_passthrough(struct blk_keyslot_manager *ksm)
626
+{
627
+ memset(ksm, 0, sizeof(*ksm));
628
+ init_rwsem(&ksm->lock);
629
+}
630
+EXPORT_SYMBOL_GPL(blk_ksm_init_passthrough);