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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2016 Intel Corporation
4 *
5 * Authors:
6 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
7 *
8 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9 *
10 * This file contains TPM2 protocol implementations of the commands
11 * used by the kernel internally.
12 */
13
14#include <linux/gfp.h>
15#include <asm/unaligned.h>
16#include "tpm.h"
17
18enum tpm2_handle_types {
19 TPM2_HT_HMAC_SESSION = 0x02000000,
20 TPM2_HT_POLICY_SESSION = 0x03000000,
21 TPM2_HT_TRANSIENT = 0x80000000,
22};
23
24struct tpm2_context {
25 __be64 sequence;
26 __be32 saved_handle;
27 __be32 hierarchy;
28 __be16 blob_size;
29} __packed;
30
31static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space)
32{
33 int i;
34
35 for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
36 if (space->session_tbl[i])
37 tpm2_flush_context(chip, space->session_tbl[i]);
38 }
39}
40
41int tpm2_init_space(struct tpm_space *space, unsigned int buf_size)
42{
43 space->context_buf = kzalloc(buf_size, GFP_KERNEL);
44 if (!space->context_buf)
45 return -ENOMEM;
46
47 space->session_buf = kzalloc(buf_size, GFP_KERNEL);
48 if (space->session_buf == NULL) {
49 kfree(space->context_buf);
50 /* Prevent caller getting a dangling pointer. */
51 space->context_buf = NULL;
52 return -ENOMEM;
53 }
54
55 space->buf_size = buf_size;
56 return 0;
57}
58
59void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space)
60{
61
62 if (tpm_try_get_ops(chip) == 0) {
63 tpm2_flush_sessions(chip, space);
64 tpm_put_ops(chip);
65 }
66
67 kfree(space->context_buf);
68 kfree(space->session_buf);
69}
70
71static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
72 unsigned int *offset, u32 *handle)
73{
74 struct tpm_buf tbuf;
75 struct tpm2_context *ctx;
76 unsigned int body_size;
77 int rc;
78
79 rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_LOAD);
80 if (rc)
81 return rc;
82
83 ctx = (struct tpm2_context *)&buf[*offset];
84 body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
85 tpm_buf_append(&tbuf, &buf[*offset], body_size);
86
87 rc = tpm_transmit_cmd(chip, &tbuf, 4, NULL);
88 if (rc < 0) {
89 dev_warn(&chip->dev, "%s: failed with a system error %d\n",
90 __func__, rc);
91 tpm_buf_destroy(&tbuf);
92 return -EFAULT;
93 } else if (tpm2_rc_value(rc) == TPM2_RC_HANDLE ||
94 rc == TPM2_RC_REFERENCE_H0) {
95 /*
96 * TPM_RC_HANDLE means that the session context can't
97 * be loaded because of an internal counter mismatch
98 * that makes the TPM think there might have been a
99 * replay. This might happen if the context was saved
100 * and loaded outside the space.
101 *
102 * TPM_RC_REFERENCE_H0 means the session has been
103 * flushed outside the space
104 */
105 *handle = 0;
106 tpm_buf_destroy(&tbuf);
107 return -ENOENT;
108 } else if (rc > 0) {
109 dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
110 __func__, rc);
111 tpm_buf_destroy(&tbuf);
112 return -EFAULT;
113 }
114
115 *handle = be32_to_cpup((__be32 *)&tbuf.data[TPM_HEADER_SIZE]);
116 *offset += body_size;
117
118 tpm_buf_destroy(&tbuf);
119 return 0;
120}
121
122static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
123 unsigned int buf_size, unsigned int *offset)
124{
125 struct tpm_buf tbuf;
126 unsigned int body_size;
127 int rc;
128
129 rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_SAVE);
130 if (rc)
131 return rc;
132
133 tpm_buf_append_u32(&tbuf, handle);
134
135 rc = tpm_transmit_cmd(chip, &tbuf, 0, NULL);
136 if (rc < 0) {
137 dev_warn(&chip->dev, "%s: failed with a system error %d\n",
138 __func__, rc);
139 tpm_buf_destroy(&tbuf);
140 return -EFAULT;
141 } else if (tpm2_rc_value(rc) == TPM2_RC_REFERENCE_H0) {
142 tpm_buf_destroy(&tbuf);
143 return -ENOENT;
144 } else if (rc) {
145 dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
146 __func__, rc);
147 tpm_buf_destroy(&tbuf);
148 return -EFAULT;
149 }
150
151 body_size = tpm_buf_length(&tbuf) - TPM_HEADER_SIZE;
152 if ((*offset + body_size) > buf_size) {
153 dev_warn(&chip->dev, "%s: out of backing storage\n", __func__);
154 tpm_buf_destroy(&tbuf);
155 return -ENOMEM;
156 }
157
158 memcpy(&buf[*offset], &tbuf.data[TPM_HEADER_SIZE], body_size);
159 *offset += body_size;
160 tpm_buf_destroy(&tbuf);
161 return 0;
162}
163
164void tpm2_flush_space(struct tpm_chip *chip)
165{
166 struct tpm_space *space = &chip->work_space;
167 int i;
168
169 for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
170 if (space->context_tbl[i] && ~space->context_tbl[i])
171 tpm2_flush_context(chip, space->context_tbl[i]);
172
173 tpm2_flush_sessions(chip, space);
174}
175
176static int tpm2_load_space(struct tpm_chip *chip)
177{
178 struct tpm_space *space = &chip->work_space;
179 unsigned int offset;
180 int i;
181 int rc;
182
183 for (i = 0, offset = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
184 if (!space->context_tbl[i])
185 continue;
186
187 /* sanity check, should never happen */
188 if (~space->context_tbl[i]) {
189 dev_err(&chip->dev, "context table is inconsistent");
190 return -EFAULT;
191 }
192
193 rc = tpm2_load_context(chip, space->context_buf, &offset,
194 &space->context_tbl[i]);
195 if (rc)
196 return rc;
197 }
198
199 for (i = 0, offset = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
200 u32 handle;
201
202 if (!space->session_tbl[i])
203 continue;
204
205 rc = tpm2_load_context(chip, space->session_buf,
206 &offset, &handle);
207 if (rc == -ENOENT) {
208 /* load failed, just forget session */
209 space->session_tbl[i] = 0;
210 } else if (rc) {
211 tpm2_flush_space(chip);
212 return rc;
213 }
214 if (handle != space->session_tbl[i]) {
215 dev_warn(&chip->dev, "session restored to wrong handle\n");
216 tpm2_flush_space(chip);
217 return -EFAULT;
218 }
219 }
220
221 return 0;
222}
223
224static bool tpm2_map_to_phandle(struct tpm_space *space, void *handle)
225{
226 u32 vhandle = be32_to_cpup((__be32 *)handle);
227 u32 phandle;
228 int i;
229
230 i = 0xFFFFFF - (vhandle & 0xFFFFFF);
231 if (i >= ARRAY_SIZE(space->context_tbl) || !space->context_tbl[i])
232 return false;
233
234 phandle = space->context_tbl[i];
235 *((__be32 *)handle) = cpu_to_be32(phandle);
236 return true;
237}
238
239static int tpm2_map_command(struct tpm_chip *chip, u32 cc, u8 *cmd)
240{
241 struct tpm_space *space = &chip->work_space;
242 unsigned int nr_handles;
243 u32 attrs;
244 __be32 *handle;
245 int i;
246
247 i = tpm2_find_cc(chip, cc);
248 if (i < 0)
249 return -EINVAL;
250
251 attrs = chip->cc_attrs_tbl[i];
252 nr_handles = (attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0);
253
254 handle = (__be32 *)&cmd[TPM_HEADER_SIZE];
255 for (i = 0; i < nr_handles; i++, handle++) {
256 if ((be32_to_cpu(*handle) & 0xFF000000) == TPM2_HT_TRANSIENT) {
257 if (!tpm2_map_to_phandle(space, handle))
258 return -EINVAL;
259 }
260 }
261
262 return 0;
263}
264
265static int tpm_find_and_validate_cc(struct tpm_chip *chip,
266 struct tpm_space *space,
267 const void *cmd, size_t len)
268{
269 const struct tpm_header *header = (const void *)cmd;
270 int i;
271 u32 cc;
272 u32 attrs;
273 unsigned int nr_handles;
274
275 if (len < TPM_HEADER_SIZE || !chip->nr_commands)
276 return -EINVAL;
277
278 cc = be32_to_cpu(header->ordinal);
279
280 i = tpm2_find_cc(chip, cc);
281 if (i < 0) {
282 dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
283 cc);
284 return -EOPNOTSUPP;
285 }
286
287 attrs = chip->cc_attrs_tbl[i];
288 nr_handles =
289 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
290 if (len < TPM_HEADER_SIZE + 4 * nr_handles)
291 goto err_len;
292
293 return cc;
294err_len:
295 dev_dbg(&chip->dev, "%s: insufficient command length %zu", __func__,
296 len);
297 return -EINVAL;
298}
299
300int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd,
301 size_t cmdsiz)
302{
303 int rc;
304 int cc;
305
306 if (!space)
307 return 0;
308
309 cc = tpm_find_and_validate_cc(chip, space, cmd, cmdsiz);
310 if (cc < 0)
311 return cc;
312
313 memcpy(&chip->work_space.context_tbl, &space->context_tbl,
314 sizeof(space->context_tbl));
315 memcpy(&chip->work_space.session_tbl, &space->session_tbl,
316 sizeof(space->session_tbl));
317 memcpy(chip->work_space.context_buf, space->context_buf,
318 space->buf_size);
319 memcpy(chip->work_space.session_buf, space->session_buf,
320 space->buf_size);
321
322 rc = tpm2_load_space(chip);
323 if (rc) {
324 tpm2_flush_space(chip);
325 return rc;
326 }
327
328 rc = tpm2_map_command(chip, cc, cmd);
329 if (rc) {
330 tpm2_flush_space(chip);
331 return rc;
332 }
333
334 chip->last_cc = cc;
335 return 0;
336}
337
338static bool tpm2_add_session(struct tpm_chip *chip, u32 handle)
339{
340 struct tpm_space *space = &chip->work_space;
341 int i;
342
343 for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++)
344 if (space->session_tbl[i] == 0)
345 break;
346
347 if (i == ARRAY_SIZE(space->session_tbl))
348 return false;
349
350 space->session_tbl[i] = handle;
351 return true;
352}
353
354static u32 tpm2_map_to_vhandle(struct tpm_space *space, u32 phandle, bool alloc)
355{
356 int i;
357
358 for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
359 if (alloc) {
360 if (!space->context_tbl[i]) {
361 space->context_tbl[i] = phandle;
362 break;
363 }
364 } else if (space->context_tbl[i] == phandle)
365 break;
366 }
367
368 if (i == ARRAY_SIZE(space->context_tbl))
369 return 0;
370
371 return TPM2_HT_TRANSIENT | (0xFFFFFF - i);
372}
373
374static int tpm2_map_response_header(struct tpm_chip *chip, u32 cc, u8 *rsp,
375 size_t len)
376{
377 struct tpm_space *space = &chip->work_space;
378 struct tpm_header *header = (struct tpm_header *)rsp;
379 u32 phandle;
380 u32 phandle_type;
381 u32 vhandle;
382 u32 attrs;
383 int i;
384
385 if (be32_to_cpu(header->return_code) != TPM2_RC_SUCCESS)
386 return 0;
387
388 i = tpm2_find_cc(chip, cc);
389 /* sanity check, should never happen */
390 if (i < 0)
391 return -EFAULT;
392
393 attrs = chip->cc_attrs_tbl[i];
394 if (!((attrs >> TPM2_CC_ATTR_RHANDLE) & 1))
395 return 0;
396
397 phandle = be32_to_cpup((__be32 *)&rsp[TPM_HEADER_SIZE]);
398 phandle_type = phandle & 0xFF000000;
399
400 switch (phandle_type) {
401 case TPM2_HT_TRANSIENT:
402 vhandle = tpm2_map_to_vhandle(space, phandle, true);
403 if (!vhandle)
404 goto out_no_slots;
405
406 *(__be32 *)&rsp[TPM_HEADER_SIZE] = cpu_to_be32(vhandle);
407 break;
408 case TPM2_HT_HMAC_SESSION:
409 case TPM2_HT_POLICY_SESSION:
410 if (!tpm2_add_session(chip, phandle))
411 goto out_no_slots;
412 break;
413 default:
414 dev_err(&chip->dev, "%s: unknown handle 0x%08X\n",
415 __func__, phandle);
416 break;
417 }
418
419 return 0;
420out_no_slots:
421 tpm2_flush_context(chip, phandle);
422 dev_warn(&chip->dev, "%s: out of slots for 0x%08X\n", __func__,
423 phandle);
424 return -ENOMEM;
425}
426
427struct tpm2_cap_handles {
428 u8 more_data;
429 __be32 capability;
430 __be32 count;
431 __be32 handles[];
432} __packed;
433
434static int tpm2_map_response_body(struct tpm_chip *chip, u32 cc, u8 *rsp,
435 size_t len)
436{
437 struct tpm_space *space = &chip->work_space;
438 struct tpm_header *header = (struct tpm_header *)rsp;
439 struct tpm2_cap_handles *data;
440 u32 phandle;
441 u32 phandle_type;
442 u32 vhandle;
443 int i;
444 int j;
445
446 if (cc != TPM2_CC_GET_CAPABILITY ||
447 be32_to_cpu(header->return_code) != TPM2_RC_SUCCESS) {
448 return 0;
449 }
450
451 if (len < TPM_HEADER_SIZE + 9)
452 return -EFAULT;
453
454 data = (void *)&rsp[TPM_HEADER_SIZE];
455 if (be32_to_cpu(data->capability) != TPM2_CAP_HANDLES)
456 return 0;
457
458 if (be32_to_cpu(data->count) > (UINT_MAX - TPM_HEADER_SIZE - 9) / 4)
459 return -EFAULT;
460
461 if (len != TPM_HEADER_SIZE + 9 + 4 * be32_to_cpu(data->count))
462 return -EFAULT;
463
464 for (i = 0, j = 0; i < be32_to_cpu(data->count); i++) {
465 phandle = be32_to_cpup((__be32 *)&data->handles[i]);
466 phandle_type = phandle & 0xFF000000;
467
468 switch (phandle_type) {
469 case TPM2_HT_TRANSIENT:
470 vhandle = tpm2_map_to_vhandle(space, phandle, false);
471 if (!vhandle)
472 break;
473
474 data->handles[j] = cpu_to_be32(vhandle);
475 j++;
476 break;
477
478 default:
479 data->handles[j] = cpu_to_be32(phandle);
480 j++;
481 break;
482 }
483
484 }
485
486 header->length = cpu_to_be32(TPM_HEADER_SIZE + 9 + 4 * j);
487 data->count = cpu_to_be32(j);
488 return 0;
489}
490
491static int tpm2_save_space(struct tpm_chip *chip)
492{
493 struct tpm_space *space = &chip->work_space;
494 unsigned int offset;
495 int i;
496 int rc;
497
498 for (i = 0, offset = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
499 if (!(space->context_tbl[i] && ~space->context_tbl[i]))
500 continue;
501
502 rc = tpm2_save_context(chip, space->context_tbl[i],
503 space->context_buf, space->buf_size,
504 &offset);
505 if (rc == -ENOENT) {
506 space->context_tbl[i] = 0;
507 continue;
508 } else if (rc)
509 return rc;
510
511 tpm2_flush_context(chip, space->context_tbl[i]);
512 space->context_tbl[i] = ~0;
513 }
514
515 for (i = 0, offset = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
516 if (!space->session_tbl[i])
517 continue;
518
519 rc = tpm2_save_context(chip, space->session_tbl[i],
520 space->session_buf, space->buf_size,
521 &offset);
522 if (rc == -ENOENT) {
523 /* handle error saving session, just forget it */
524 space->session_tbl[i] = 0;
525 } else if (rc < 0) {
526 tpm2_flush_space(chip);
527 return rc;
528 }
529 }
530
531 return 0;
532}
533
534int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
535 void *buf, size_t *bufsiz)
536{
537 struct tpm_header *header = buf;
538 int rc;
539
540 if (!space)
541 return 0;
542
543 rc = tpm2_map_response_header(chip, chip->last_cc, buf, *bufsiz);
544 if (rc) {
545 tpm2_flush_space(chip);
546 goto out;
547 }
548
549 rc = tpm2_map_response_body(chip, chip->last_cc, buf, *bufsiz);
550 if (rc) {
551 tpm2_flush_space(chip);
552 goto out;
553 }
554
555 rc = tpm2_save_space(chip);
556 if (rc) {
557 tpm2_flush_space(chip);
558 goto out;
559 }
560
561 *bufsiz = be32_to_cpu(header->length);
562
563 memcpy(&space->context_tbl, &chip->work_space.context_tbl,
564 sizeof(space->context_tbl));
565 memcpy(&space->session_tbl, &chip->work_space.session_tbl,
566 sizeof(space->session_tbl));
567 memcpy(space->context_buf, chip->work_space.context_buf,
568 space->buf_size);
569 memcpy(space->session_buf, chip->work_space.session_buf,
570 space->buf_size);
571
572 return 0;
573out:
574 dev_err(&chip->dev, "%s: error %d\n", __func__, rc);
575 return rc;
576}
577
578/*
579 * Put the reference to the main device.
580 */
581static void tpm_devs_release(struct device *dev)
582{
583 struct tpm_chip *chip = container_of(dev, struct tpm_chip, devs);
584
585 /* release the master device reference */
586 put_device(&chip->dev);
587}
588
589/*
590 * Remove the device file for exposed TPM spaces and release the device
591 * reference. This may also release the reference to the master device.
592 */
593void tpm_devs_remove(struct tpm_chip *chip)
594{
595 cdev_device_del(&chip->cdevs, &chip->devs);
596 put_device(&chip->devs);
597}
598
599/*
600 * Add a device file to expose TPM spaces. Also take a reference to the
601 * main device.
602 */
603int tpm_devs_add(struct tpm_chip *chip)
604{
605 int rc;
606
607 device_initialize(&chip->devs);
608 chip->devs.parent = chip->dev.parent;
609 chip->devs.class = &tpmrm_class;
610
611 /*
612 * Get extra reference on main device to hold on behalf of devs.
613 * This holds the chip structure while cdevs is in use. The
614 * corresponding put is in the tpm_devs_release.
615 */
616 get_device(&chip->dev);
617 chip->devs.release = tpm_devs_release;
618 chip->devs.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num + TPM_NUM_DEVICES);
619 cdev_init(&chip->cdevs, &tpmrm_fops);
620 chip->cdevs.owner = THIS_MODULE;
621
622 rc = dev_set_name(&chip->devs, "tpmrm%d", chip->dev_num);
623 if (rc)
624 goto err_put_devs;
625
626 rc = cdev_device_add(&chip->cdevs, &chip->devs);
627 if (rc) {
628 dev_err(&chip->devs,
629 "unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
630 dev_name(&chip->devs), MAJOR(chip->devs.devt),
631 MINOR(chip->devs.devt), rc);
632 goto err_put_devs;
633 }
634
635 return 0;
636
637err_put_devs:
638 put_device(&chip->devs);
639
640 return rc;
641}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2016 Intel Corporation
4 *
5 * Authors:
6 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
7 *
8 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9 *
10 * This file contains TPM2 protocol implementations of the commands
11 * used by the kernel internally.
12 */
13
14#include <linux/gfp.h>
15#include <linux/unaligned.h>
16#include "tpm.h"
17
18enum tpm2_handle_types {
19 TPM2_HT_HMAC_SESSION = 0x02000000,
20 TPM2_HT_POLICY_SESSION = 0x03000000,
21 TPM2_HT_TRANSIENT = 0x80000000,
22};
23
24struct tpm2_context {
25 __be64 sequence;
26 __be32 saved_handle;
27 __be32 hierarchy;
28 __be16 blob_size;
29} __packed;
30
31static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space)
32{
33 int i;
34
35 for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
36 if (space->session_tbl[i])
37 tpm2_flush_context(chip, space->session_tbl[i]);
38 }
39}
40
41int tpm2_init_space(struct tpm_space *space, unsigned int buf_size)
42{
43 space->context_buf = kzalloc(buf_size, GFP_KERNEL);
44 if (!space->context_buf)
45 return -ENOMEM;
46
47 space->session_buf = kzalloc(buf_size, GFP_KERNEL);
48 if (space->session_buf == NULL) {
49 kfree(space->context_buf);
50 /* Prevent caller getting a dangling pointer. */
51 space->context_buf = NULL;
52 return -ENOMEM;
53 }
54
55 space->buf_size = buf_size;
56 return 0;
57}
58
59void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space)
60{
61
62 if (tpm_try_get_ops(chip) == 0) {
63 tpm2_flush_sessions(chip, space);
64 tpm_put_ops(chip);
65 }
66
67 kfree(space->context_buf);
68 kfree(space->session_buf);
69}
70
71int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
72 unsigned int *offset, u32 *handle)
73{
74 struct tpm_buf tbuf;
75 struct tpm2_context *ctx;
76 unsigned int body_size;
77 int rc;
78
79 rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_LOAD);
80 if (rc)
81 return rc;
82
83 ctx = (struct tpm2_context *)&buf[*offset];
84 body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
85 tpm_buf_append(&tbuf, &buf[*offset], body_size);
86
87 rc = tpm_transmit_cmd(chip, &tbuf, 4, NULL);
88 if (rc < 0) {
89 dev_warn(&chip->dev, "%s: failed with a system error %d\n",
90 __func__, rc);
91 tpm_buf_destroy(&tbuf);
92 return -EFAULT;
93 } else if (tpm2_rc_value(rc) == TPM2_RC_HANDLE ||
94 rc == TPM2_RC_REFERENCE_H0) {
95 /*
96 * TPM_RC_HANDLE means that the session context can't
97 * be loaded because of an internal counter mismatch
98 * that makes the TPM think there might have been a
99 * replay. This might happen if the context was saved
100 * and loaded outside the space.
101 *
102 * TPM_RC_REFERENCE_H0 means the session has been
103 * flushed outside the space
104 */
105 *handle = 0;
106 tpm_buf_destroy(&tbuf);
107 return -ENOENT;
108 } else if (tpm2_rc_value(rc) == TPM2_RC_INTEGRITY) {
109 tpm_buf_destroy(&tbuf);
110 return -EINVAL;
111 } else if (rc > 0) {
112 dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
113 __func__, rc);
114 tpm_buf_destroy(&tbuf);
115 return -EFAULT;
116 }
117
118 *handle = be32_to_cpup((__be32 *)&tbuf.data[TPM_HEADER_SIZE]);
119 *offset += body_size;
120
121 tpm_buf_destroy(&tbuf);
122 return 0;
123}
124
125int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
126 unsigned int buf_size, unsigned int *offset)
127{
128 struct tpm_buf tbuf;
129 unsigned int body_size;
130 int rc;
131
132 rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_SAVE);
133 if (rc)
134 return rc;
135
136 tpm_buf_append_u32(&tbuf, handle);
137
138 rc = tpm_transmit_cmd(chip, &tbuf, 0, NULL);
139 if (rc < 0) {
140 dev_warn(&chip->dev, "%s: failed with a system error %d\n",
141 __func__, rc);
142 tpm_buf_destroy(&tbuf);
143 return -EFAULT;
144 } else if (tpm2_rc_value(rc) == TPM2_RC_REFERENCE_H0) {
145 tpm_buf_destroy(&tbuf);
146 return -ENOENT;
147 } else if (rc) {
148 dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
149 __func__, rc);
150 tpm_buf_destroy(&tbuf);
151 return -EFAULT;
152 }
153
154 body_size = tpm_buf_length(&tbuf) - TPM_HEADER_SIZE;
155 if ((*offset + body_size) > buf_size) {
156 dev_warn(&chip->dev, "%s: out of backing storage\n", __func__);
157 tpm_buf_destroy(&tbuf);
158 return -ENOMEM;
159 }
160
161 memcpy(&buf[*offset], &tbuf.data[TPM_HEADER_SIZE], body_size);
162 *offset += body_size;
163 tpm_buf_destroy(&tbuf);
164 return 0;
165}
166
167void tpm2_flush_space(struct tpm_chip *chip)
168{
169 struct tpm_space *space = &chip->work_space;
170 int i;
171
172 if (!space)
173 return;
174
175 for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
176 if (space->context_tbl[i] && ~space->context_tbl[i])
177 tpm2_flush_context(chip, space->context_tbl[i]);
178
179 tpm2_flush_sessions(chip, space);
180}
181
182static int tpm2_load_space(struct tpm_chip *chip)
183{
184 struct tpm_space *space = &chip->work_space;
185 unsigned int offset;
186 int i;
187 int rc;
188
189 for (i = 0, offset = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
190 if (!space->context_tbl[i])
191 continue;
192
193 /* sanity check, should never happen */
194 if (~space->context_tbl[i]) {
195 dev_err(&chip->dev, "context table is inconsistent");
196 return -EFAULT;
197 }
198
199 rc = tpm2_load_context(chip, space->context_buf, &offset,
200 &space->context_tbl[i]);
201 if (rc)
202 return rc;
203 }
204
205 for (i = 0, offset = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
206 u32 handle;
207
208 if (!space->session_tbl[i])
209 continue;
210
211 rc = tpm2_load_context(chip, space->session_buf,
212 &offset, &handle);
213 if (rc == -ENOENT) {
214 /* load failed, just forget session */
215 space->session_tbl[i] = 0;
216 } else if (rc) {
217 tpm2_flush_space(chip);
218 return rc;
219 }
220 if (handle != space->session_tbl[i]) {
221 dev_warn(&chip->dev, "session restored to wrong handle\n");
222 tpm2_flush_space(chip);
223 return -EFAULT;
224 }
225 }
226
227 return 0;
228}
229
230static bool tpm2_map_to_phandle(struct tpm_space *space, void *handle)
231{
232 u32 vhandle = be32_to_cpup((__be32 *)handle);
233 u32 phandle;
234 int i;
235
236 i = 0xFFFFFF - (vhandle & 0xFFFFFF);
237 if (i >= ARRAY_SIZE(space->context_tbl) || !space->context_tbl[i])
238 return false;
239
240 phandle = space->context_tbl[i];
241 *((__be32 *)handle) = cpu_to_be32(phandle);
242 return true;
243}
244
245static int tpm2_map_command(struct tpm_chip *chip, u32 cc, u8 *cmd)
246{
247 struct tpm_space *space = &chip->work_space;
248 unsigned int nr_handles;
249 u32 attrs;
250 __be32 *handle;
251 int i;
252
253 i = tpm2_find_cc(chip, cc);
254 if (i < 0)
255 return -EINVAL;
256
257 attrs = chip->cc_attrs_tbl[i];
258 nr_handles = (attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0);
259
260 handle = (__be32 *)&cmd[TPM_HEADER_SIZE];
261 for (i = 0; i < nr_handles; i++, handle++) {
262 if ((be32_to_cpu(*handle) & 0xFF000000) == TPM2_HT_TRANSIENT) {
263 if (!tpm2_map_to_phandle(space, handle))
264 return -EINVAL;
265 }
266 }
267
268 return 0;
269}
270
271static int tpm_find_and_validate_cc(struct tpm_chip *chip,
272 struct tpm_space *space,
273 const void *cmd, size_t len)
274{
275 const struct tpm_header *header = (const void *)cmd;
276 int i;
277 u32 cc;
278 u32 attrs;
279 unsigned int nr_handles;
280
281 if (len < TPM_HEADER_SIZE || !chip->nr_commands)
282 return -EINVAL;
283
284 cc = be32_to_cpu(header->ordinal);
285
286 i = tpm2_find_cc(chip, cc);
287 if (i < 0) {
288 dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
289 cc);
290 return -EOPNOTSUPP;
291 }
292
293 attrs = chip->cc_attrs_tbl[i];
294 nr_handles =
295 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
296 if (len < TPM_HEADER_SIZE + 4 * nr_handles)
297 goto err_len;
298
299 return cc;
300err_len:
301 dev_dbg(&chip->dev, "%s: insufficient command length %zu", __func__,
302 len);
303 return -EINVAL;
304}
305
306int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u8 *cmd,
307 size_t cmdsiz)
308{
309 int rc;
310 int cc;
311
312 if (!space)
313 return 0;
314
315 cc = tpm_find_and_validate_cc(chip, space, cmd, cmdsiz);
316 if (cc < 0)
317 return cc;
318
319 memcpy(&chip->work_space.context_tbl, &space->context_tbl,
320 sizeof(space->context_tbl));
321 memcpy(&chip->work_space.session_tbl, &space->session_tbl,
322 sizeof(space->session_tbl));
323 memcpy(chip->work_space.context_buf, space->context_buf,
324 space->buf_size);
325 memcpy(chip->work_space.session_buf, space->session_buf,
326 space->buf_size);
327
328 rc = tpm2_load_space(chip);
329 if (rc) {
330 tpm2_flush_space(chip);
331 return rc;
332 }
333
334 rc = tpm2_map_command(chip, cc, cmd);
335 if (rc) {
336 tpm2_flush_space(chip);
337 return rc;
338 }
339
340 chip->last_cc = cc;
341 return 0;
342}
343
344static bool tpm2_add_session(struct tpm_chip *chip, u32 handle)
345{
346 struct tpm_space *space = &chip->work_space;
347 int i;
348
349 for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++)
350 if (space->session_tbl[i] == 0)
351 break;
352
353 if (i == ARRAY_SIZE(space->session_tbl))
354 return false;
355
356 space->session_tbl[i] = handle;
357 return true;
358}
359
360static u32 tpm2_map_to_vhandle(struct tpm_space *space, u32 phandle, bool alloc)
361{
362 int i;
363
364 for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
365 if (alloc) {
366 if (!space->context_tbl[i]) {
367 space->context_tbl[i] = phandle;
368 break;
369 }
370 } else if (space->context_tbl[i] == phandle)
371 break;
372 }
373
374 if (i == ARRAY_SIZE(space->context_tbl))
375 return 0;
376
377 return TPM2_HT_TRANSIENT | (0xFFFFFF - i);
378}
379
380static int tpm2_map_response_header(struct tpm_chip *chip, u32 cc, u8 *rsp,
381 size_t len)
382{
383 struct tpm_space *space = &chip->work_space;
384 struct tpm_header *header = (struct tpm_header *)rsp;
385 u32 phandle;
386 u32 phandle_type;
387 u32 vhandle;
388 u32 attrs;
389 int i;
390
391 if (be32_to_cpu(header->return_code) != TPM2_RC_SUCCESS)
392 return 0;
393
394 i = tpm2_find_cc(chip, cc);
395 /* sanity check, should never happen */
396 if (i < 0)
397 return -EFAULT;
398
399 attrs = chip->cc_attrs_tbl[i];
400 if (!((attrs >> TPM2_CC_ATTR_RHANDLE) & 1))
401 return 0;
402
403 phandle = be32_to_cpup((__be32 *)&rsp[TPM_HEADER_SIZE]);
404 phandle_type = phandle & 0xFF000000;
405
406 switch (phandle_type) {
407 case TPM2_HT_TRANSIENT:
408 vhandle = tpm2_map_to_vhandle(space, phandle, true);
409 if (!vhandle)
410 goto out_no_slots;
411
412 *(__be32 *)&rsp[TPM_HEADER_SIZE] = cpu_to_be32(vhandle);
413 break;
414 case TPM2_HT_HMAC_SESSION:
415 case TPM2_HT_POLICY_SESSION:
416 if (!tpm2_add_session(chip, phandle))
417 goto out_no_slots;
418 break;
419 default:
420 dev_err(&chip->dev, "%s: unknown handle 0x%08X\n",
421 __func__, phandle);
422 break;
423 }
424
425 return 0;
426out_no_slots:
427 tpm2_flush_context(chip, phandle);
428 dev_warn(&chip->dev, "%s: out of slots for 0x%08X\n", __func__,
429 phandle);
430 return -ENOMEM;
431}
432
433struct tpm2_cap_handles {
434 u8 more_data;
435 __be32 capability;
436 __be32 count;
437 __be32 handles[];
438} __packed;
439
440static int tpm2_map_response_body(struct tpm_chip *chip, u32 cc, u8 *rsp,
441 size_t len)
442{
443 struct tpm_space *space = &chip->work_space;
444 struct tpm_header *header = (struct tpm_header *)rsp;
445 struct tpm2_cap_handles *data;
446 u32 phandle;
447 u32 phandle_type;
448 u32 vhandle;
449 int i;
450 int j;
451
452 if (cc != TPM2_CC_GET_CAPABILITY ||
453 be32_to_cpu(header->return_code) != TPM2_RC_SUCCESS) {
454 return 0;
455 }
456
457 if (len < TPM_HEADER_SIZE + 9)
458 return -EFAULT;
459
460 data = (void *)&rsp[TPM_HEADER_SIZE];
461 if (be32_to_cpu(data->capability) != TPM2_CAP_HANDLES)
462 return 0;
463
464 if (be32_to_cpu(data->count) > (UINT_MAX - TPM_HEADER_SIZE - 9) / 4)
465 return -EFAULT;
466
467 if (len != TPM_HEADER_SIZE + 9 + 4 * be32_to_cpu(data->count))
468 return -EFAULT;
469
470 for (i = 0, j = 0; i < be32_to_cpu(data->count); i++) {
471 phandle = be32_to_cpup((__be32 *)&data->handles[i]);
472 phandle_type = phandle & 0xFF000000;
473
474 switch (phandle_type) {
475 case TPM2_HT_TRANSIENT:
476 vhandle = tpm2_map_to_vhandle(space, phandle, false);
477 if (!vhandle)
478 break;
479
480 data->handles[j] = cpu_to_be32(vhandle);
481 j++;
482 break;
483
484 default:
485 data->handles[j] = cpu_to_be32(phandle);
486 j++;
487 break;
488 }
489
490 }
491
492 header->length = cpu_to_be32(TPM_HEADER_SIZE + 9 + 4 * j);
493 data->count = cpu_to_be32(j);
494 return 0;
495}
496
497static int tpm2_save_space(struct tpm_chip *chip)
498{
499 struct tpm_space *space = &chip->work_space;
500 unsigned int offset;
501 int i;
502 int rc;
503
504 for (i = 0, offset = 0; i < ARRAY_SIZE(space->context_tbl); i++) {
505 if (!(space->context_tbl[i] && ~space->context_tbl[i]))
506 continue;
507
508 rc = tpm2_save_context(chip, space->context_tbl[i],
509 space->context_buf, space->buf_size,
510 &offset);
511 if (rc == -ENOENT) {
512 space->context_tbl[i] = 0;
513 continue;
514 } else if (rc)
515 return rc;
516
517 tpm2_flush_context(chip, space->context_tbl[i]);
518 space->context_tbl[i] = ~0;
519 }
520
521 for (i = 0, offset = 0; i < ARRAY_SIZE(space->session_tbl); i++) {
522 if (!space->session_tbl[i])
523 continue;
524
525 rc = tpm2_save_context(chip, space->session_tbl[i],
526 space->session_buf, space->buf_size,
527 &offset);
528 if (rc == -ENOENT) {
529 /* handle error saving session, just forget it */
530 space->session_tbl[i] = 0;
531 } else if (rc < 0) {
532 tpm2_flush_space(chip);
533 return rc;
534 }
535 }
536
537 return 0;
538}
539
540int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space,
541 void *buf, size_t *bufsiz)
542{
543 struct tpm_header *header = buf;
544 int rc;
545
546 if (!space)
547 return 0;
548
549 rc = tpm2_map_response_header(chip, chip->last_cc, buf, *bufsiz);
550 if (rc) {
551 tpm2_flush_space(chip);
552 goto out;
553 }
554
555 rc = tpm2_map_response_body(chip, chip->last_cc, buf, *bufsiz);
556 if (rc) {
557 tpm2_flush_space(chip);
558 goto out;
559 }
560
561 rc = tpm2_save_space(chip);
562 if (rc) {
563 tpm2_flush_space(chip);
564 goto out;
565 }
566
567 *bufsiz = be32_to_cpu(header->length);
568
569 memcpy(&space->context_tbl, &chip->work_space.context_tbl,
570 sizeof(space->context_tbl));
571 memcpy(&space->session_tbl, &chip->work_space.session_tbl,
572 sizeof(space->session_tbl));
573 memcpy(space->context_buf, chip->work_space.context_buf,
574 space->buf_size);
575 memcpy(space->session_buf, chip->work_space.session_buf,
576 space->buf_size);
577
578 return 0;
579out:
580 dev_err(&chip->dev, "%s: error %d\n", __func__, rc);
581 return rc;
582}
583
584/*
585 * Put the reference to the main device.
586 */
587static void tpm_devs_release(struct device *dev)
588{
589 struct tpm_chip *chip = container_of(dev, struct tpm_chip, devs);
590
591 /* release the master device reference */
592 put_device(&chip->dev);
593}
594
595/*
596 * Remove the device file for exposed TPM spaces and release the device
597 * reference. This may also release the reference to the master device.
598 */
599void tpm_devs_remove(struct tpm_chip *chip)
600{
601 cdev_device_del(&chip->cdevs, &chip->devs);
602 put_device(&chip->devs);
603}
604
605/*
606 * Add a device file to expose TPM spaces. Also take a reference to the
607 * main device.
608 */
609int tpm_devs_add(struct tpm_chip *chip)
610{
611 int rc;
612
613 device_initialize(&chip->devs);
614 chip->devs.parent = chip->dev.parent;
615 chip->devs.class = &tpmrm_class;
616
617 /*
618 * Get extra reference on main device to hold on behalf of devs.
619 * This holds the chip structure while cdevs is in use. The
620 * corresponding put is in the tpm_devs_release.
621 */
622 get_device(&chip->dev);
623 chip->devs.release = tpm_devs_release;
624 chip->devs.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num + TPM_NUM_DEVICES);
625 cdev_init(&chip->cdevs, &tpmrm_fops);
626 chip->cdevs.owner = THIS_MODULE;
627
628 rc = dev_set_name(&chip->devs, "tpmrm%d", chip->dev_num);
629 if (rc)
630 goto err_put_devs;
631
632 rc = cdev_device_add(&chip->cdevs, &chip->devs);
633 if (rc) {
634 dev_err(&chip->devs,
635 "unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
636 dev_name(&chip->devs), MAJOR(chip->devs.devt),
637 MINOR(chip->devs.devt), rc);
638 goto err_put_devs;
639 }
640
641 return 0;
642
643err_put_devs:
644 put_device(&chip->devs);
645
646 return rc;
647}