/* Copyright 2019 The Chromium OS Authors. All rights reserved. * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include #include #include "test/nvmem_test.h" #include "common.h" #include "board.h" #include "console.h" #include "crypto_api.h" #include "flash.h" #include "flash_log.h" #include "new_nvmem.h" #include "nvmem.h" #include "nvmem_vars.h" #include "shared_mem.h" #include "system.h" #include "system_chip.h" #include "task.h" #include "timer.h" #define CPRINTS(format, args...) cprints(CC_SYSTEM, format, ##args) /* * ==== Overview * * This file is the implementation of the new TPM NVMEM flash storage layer. * These are major differences compared to the legacy implementation: * * NVMEM TPM objects are stored in flash in separate containers, each one * protected by hash and possibly encrypted. When nvmem_commit() is invoked, * only objects changed in the NVMEM cache are updated in the flash. * * The (key, value) pairs are also stored in flash in the same kind of * separate containers. There is no special area allocated for the (key, value) * pairs in flash, they are interleaved with TPM objects. * * The (key, value) pairs are not kept in the NVMEM cache, they are stored in * flash only. This causes a few deviations from the legacy (key, value) pair * interface: * * - no need to initialize (key, value) storage separately, initvars() API is * not there. * * - when the user is retrieving a (key, value) object, he/she is given a * dynamically allocated buffer, which needs to be explicitly released by * calling the new API: freevar(). * * - the (key. value) pairs, if modified, are updated in flash immediately, * not after nvmem_commit() is called. * * Storing (key, value) pairs in the flash frees up 272 bytes of the cache * space previously used, but makes it more difficult to control how flash * memory is split between TPM objects and (key, value) pairs. A soft limit of * 1K is introduced, limiting the total space used by (key, value) pairs data, * not including tuple headers. * * ===== Organizing flash storage * * The total space used by the NVMEM in flash is reduced from 24 to 20 * kilobytes, five 2K pages at the top of each flash bank. These pages are * concatenated into a single storage space, based on the page header placed * at the bottom of each page (struct nn_page_header). The page header * includes a 21 bit page number (this allows to order pages properly on * initialization), the offset of the first data object in the page and the * hash of the entire header. * * Yet another limitation of the new scheme is that no object stored in NVMEM * can exceed the flash page size less the page header size and container * header size. This allows for objects as large as 2035 bytes. Objects can * span flash pages. Note that reserved TPM object STATE_CLEAR_DATA exceeds 2K * in size, this is why one of its components (the .pcrSave field) is stored * in flash separately. * * ===== Object containers * * The container header (struct nn_container) describes the contained TPM * object or (key, value) pair, along with the size, and also includes the * hash of the entire container calculated when the hash field is set to zero. * * When an object needs to be updated, it is stored at the end of the used * flash space in a container with the higher .generation field value, and * then the older container's type field is erased, thus marking it as a * deleted object. The idea is that when initializing NVMEM cache after reset, * in case two instances of the same object are found in the flash because the * new instance was saved, but the old instance was not erased because of some * failure, the instance with larger .generation field value wins. Note that * this error recovery procedure is supplemented by use of transaction * delimiter objects described below. * * The container type field is duplicated in the container header, this allows * verification of the container hash after even the object was erased. * * In order to be able to erase the type the container must start at the 4 * byte boundary. This in turn requires that each container is padded such * that total storage taken by the container is divisible by 4. * * To be able to tell if two containers contain two instances of the same * object, one needs to be able to identify the object stored in the container. * For the three distinct types of objects it works as follows: * * - (key, value) pair: key, stored in the contained tuple. * * - reserved tpm object: the first byte stored in the container. PCR * values from STATE_CLEAR_DATA.pcrSave field are stored as separate * reserved objects with the appropriate first bytes. * * - evictable tpm object: the first 4 bytes stored in the container, the * evictable TTPM object ID. * * Don't forget that the contents are usually encrypted. Decryption is needed * each time a stored object needs to be examined. * * Reserved objects of types STATE_CLEAR_DATA and STATE_RESET_DATA are very * big and are stored in the flash in marshaled form. On top of 'regular' TPM2 * style marshaling, PCRs found in the STATE_CLEAR_DATA object are stored in * separate containers. * * ===== Storage compaction * * Keeping adding changed values at the end of the flash space would * inevitably cause space overflow, unless something is done about it. This is * where flash compaction kicks in: as soon as there are just three free flash * pages left the stored objects are moved to the end of the space, which * results in earlier used pages being freed and added to the pool of * available flash pages. * * A great improvement to this storage compaction process would be grouping * the objects such that the rarely changing ones occupy flash pages at the * lower page indices. In this case when compaction starts, the pages not * containing erased objects would not have to be re-written. This * optimization is left as a future enhancement. * * ===== Committing TPM changes * * When nvmem_commit() is invoked it is necessary to identify which TPM * objects in the cache have changed and require saving. Remember, that (key, * value) pairs are not held in the cache any more and are saved in the flash * immediately, so they do not have to be dealt with during commit. * * The commit procedure starts with iterating over the evictable objects space * in the NVMEM cache, storing in an array offsets of all evictable objects it * finds there. Then it iterates over flash contents skipping over (key, * value) pairs. * * For each reserved object stored in flash, it compares its stored value with * the value stored in the cache at known fixed location. If the value has * changed, a new reserved object instance is saved in flash. This approach * requires that all reserved objects are present in the flash, otherwise * there is nothing to compare the cached instance of the object with. This is * enforced by the init function. * * For each evictable object stored in flash, it checks if that object is * still in the cache using the previously collected array of offsets. If the * object is not in the cache, it must have been deleted by the TPM. The * function deletes it from the flash as well. If the object is in the cache, * its offset is removed from the array to indicate that the object has been * processed. Then if the object value has changed, the new instance is added * and the old instance erased. After this the only offsets left in the array * are offsets of new objects, not yet saved in the flash. All these remaining * objects get saved. * * To ensure transaction integrity, object deletions are just scheduled and * not processed immediately, the deletion happens after all new instances * have been saved in flash. See more about transaction delimiters below. * * ===== Migration from legacy storage and reclaiming flash space * * To be able to migrate existing devices from the legacy storage format the * initialization code checks if a full 12K flash partition is still present, * and if so - copies its contents into the cache and invokes the migration * function. The function erases the alternative partition and creates a list * of 5 pages available for the new format (remember, the flash footprint of * the new scheme is smaller, only 10K is available in each half). * * The (key, value) pairs and TPM objects are stored in the new format as * described, and then the legacy partition is erased and its pages are added * to the list of free pages. This approach would fail if the existing TPM * storage would exceed 10K, but this is extremely unlikely, especially since * the large reserved objects are stored by the new scheme in marshaled form. * This frees up a lot of flash space. * * Eventually it will be possible to reclaim the bottom 2K page per flash half * currently used by the legacy scheme, but this would be possible only after * migration is over. The plan is to keep a few Cr50 versions supporting the * migration process, and then drop the migration code and rearrange the * memory map and reclaim the freed pages. Chrome OS will always carry a * migrating capable Cr50 version along with the latest one to make sure that * even Chrome OS devices which had not updated their Cr50 code in a long * while can be migrated in two steps. * * ===== Initialization, including erased/corrupted flash * * On regular startup (no legacy partition found) the flash pages dedicated to * NVMEM storage are examined, pages with valid headers are included in the * list of available pages, sorted by the page number. Erased pages are kept * in a separate list. Pages which are not fully erased (but do not have a * valid header) are considered corrupted, are erased, and added to the second * list. * * After that the contents of the ordered flash pages is read, all discovered * TPM objects are verified and saved in the cache. * * To enforce that all reserved TPM objects are present in the flash, the init * routine maintains a bitmap of the reserved objects it found while * initializing. In the case when after the scan of the entire NVMEM flash it * turns out that some reserved objects have not been encountered, the init * routine creates new flash instances of the missing reserved objects with * default value of zero. This takes care of both initializing from empty * flash and a case when a reserved object disappears due to a bug. * * ===== Transactions support * * It is important to make sure that TPM changes are grouped together. It came * naturally with the legacy scheme where each time nvmem_save() was called, * the entire cache snapshot was saved in the flash. With the new scheme some * extra effort is required. * * Transaction delimiters are represented by containers of the appropriate * type and the payload size of zero. When nvmem_save() operation is started, * the new objects get written into flash and the objects requiring deletion * are kept in the list. Once all new objects are added to the flash, the * transaction delimiter is written, ending up at the top of the used flash. * After that the objects scheduled for deletion are deleted, and then the * transaction delimiter is also marked 'deleted'. * * So, during initialization the flash could be in one of three states: * * - thre is an erased transaction delimiter at the top * . this is the normal state after successful commit operation. * * - there is transaction delimiter at the top, but it is not erased. * . this is the case where the new objects were saved in flash, but some of * the old instances might still be present not erased. The recovery * procedure finds all duplicates of the objects present between two most * recent delimiters and erases them. * * - there is no transaction delimiter on the top. * . this is the case where nvmem_save() was interrupted before all new * values have been written into the flash. The recovery procedure finds * all TPM objects above the last valid delimiter in the flash and erases * them all. * * ===== Handling failures * * This implementation is no better in handling failures than the legacy one, * it in fact is even worse, because if a failure happened during legacy * commit operation, at least the earlier saved partition would be available. * If failure happens during this implementation's save or compaction process, * there is a risk of ending up with a corrupted or inconsistent flash * contents, even though the use of transaction delimiters narrows the failure * window significantly. * * This first draft is offered for review and to facilitate testing and * discussion about how failures should be addressed. * * ===== Missing stuff * * Presently not much thought has been given to locking and preventing * problems caused by task preemption. The legacy scheme is still in place, * but it might require improvements. */ /* * This code relies on the fact that space dedicated to flash NVMEM storage is * sufficient to guarantee that the entire NVMEM snapshot can fit into it * comfortably. The assert below is a very liberal computation which * guarantees this assumption. Note that marshaling huge reserved structures * reduces amount of required flash space, and this is not accounted for in * this calculation. Space allocated for 200 container descriptors is also way * more than required. */ /* * Fuzz testing does not enforce proper size definitions, causing the below * assert failure. */ BUILD_ASSERT((NEW_NVMEM_TOTAL_PAGES * CONFIG_FLASH_BANK_SIZE) > (MAX_VAR_TOTAL_SPACE + NV_MEMORY_SIZE + 200 * (sizeof(struct nn_container)) + CONFIG_FLASH_BANK_SIZE * 2)); /* Maximum number of evictable objects we support. */ #define MAX_STORED_EVICTABLE_OBJECTS 20 /* * Container for storing (key, value) pairs, a.k.a. vars during read. Actual * vars would never be this large, but when looking for vars we need to be * able to iterate over and verify all objects in the flash, hence the max * body size. */ struct max_var_container { struct nn_container c_header; struct tuple t_header; uint8_t body[CONFIG_FLASH_BANK_SIZE - sizeof(struct nn_container) - sizeof(struct tuple)]; } __packed; /* * Limit of the number of objects which can be updated in one TPM transaction, * reserved and evictable total. This is much more than practical maximum. */ #define MAX_DELETE_CANDIDATES 30 static struct delete_candidates { size_t num_candidates; const struct nn_container *candidates[MAX_DELETE_CANDIDATES]; } *del_candidates; /* * This array contains a list of flash pages indices (0..255 range) sorted by * the page header page number filed. Erased pages are kept at the tail of the * list. */ static uint8_t page_list[NEW_NVMEM_TOTAL_PAGES]; static uint32_t next_evict_obj_base; static uint8_t init_in_progress; /* * Mutex to protect flash space containing NVMEM objects. All operations * modifying the flash contents or relying on its consistency (like searching * in the flash) should acquire this mutex before proceeding. * * The interfaces grabbing this mutex are * * new_nvmem_migrate() * new_nvmem_init() * new_nvmem_save() * getvar() * setvar() * nvmem_erase_tpm_data() * * The only static function using the mutex is browse_flash_contents() which * can be invoked from the CLI and while it never modifies the flash contents, * it still has to be protected to be able to properly iterate over the entire * flash contents. */ static struct mutex flash_mtx; /* * Wrappers around locking/unlocking mutex make it easier to debug issues by * adding with minimal code changes like printouts of line numbers where the * functions are invoked from. */ static void lock_mutex(int line_num) { mutex_lock(&flash_mtx); } static void unlock_mutex(int line_num) { mutex_unlock(&flash_mtx); } /* * Total space taken by key, value pairs in flash. It is limited to give TPM * objects priority. */ test_export_static uint16_t total_var_space; /* The main context used when adding objects to NVMEM. */ test_export_static struct access_tracker master_at; test_export_static enum ec_error_list browse_flash_contents(int print); static enum ec_error_list save_container(struct nn_container *nc); static void invalidate_nvmem_flash(void); /* Log NVMEM problem as per passed in payload and size, and reboot. */ static void report_failure(struct nvmem_failure_payload *payload, size_t payload_union_size) { if (init_in_progress) { /* * This must be a rolling reboot, let's invalidate flash * storage to stop this. */ invalidate_nvmem_flash(); } flash_log_add_event(FE_LOG_NVMEM, payload_union_size + offsetof(struct nvmem_failure_payload, size), payload); ccprintf("Logging failure %d, will %sreinit\n", payload->failure_type, init_in_progress ? "" : "not "); if (init_in_progress) { struct nvmem_failure_payload fp; fp.failure_type = NVMEMF_NVMEM_WIPE; flash_log_add_event( FE_LOG_NVMEM, offsetof(struct nvmem_failure_payload, size), &fp); } cflush(); system_reset(SYSTEM_RESET_MANUALLY_TRIGGERED | SYSTEM_RESET_HARD); } static void report_no_payload_failure(enum nvmem_failure_type type) { struct nvmem_failure_payload fp; fp.failure_type = type; report_failure(&fp, 0); } /* * This function allocates a buffer of the requested size. * * Heap space could be very limited and at times there could be not enough * memory in the heap to allocate. This should not be considered a failure, * polling should be used instead. On a properly functioning device the memory * would become available. If it is not - there is not much we can do, we'll * have to reboot adding a log entry. */ static void *get_scratch_buffer(size_t size) { char *buf; int i; struct nvmem_failure_payload fp; /* * Wait up to a 5 seconds in case some other operation is under * way. */ for (i = 0; i < 50; i++) { int rv; rv = shared_mem_acquire(size, &buf); if (rv == EC_SUCCESS) { if (i) CPRINTS("%s: waited %d cycles!", __func__, i); return buf; } usleep(100 * MSEC); } fp.failure_type = NVMEMF_MALLOC; fp.size = size; report_failure(&fp, sizeof(fp.size)); /* Just to keep the compiler happy, this is never reached. */ return NULL; } /* Helper function returning actual size used by NVMEM in flash. */ static size_t total_used_size(void) { return master_at.list_index * CONFIG_FLASH_BANK_SIZE + master_at.mt.data_offset; } /* * Helper functions to set a bit a bit at a certain index in a bitmap array * and to check if the bit is set. The caller must guarantee that the bitmap * array is large enough for the index. */ static int bitmap_bit_check(const uint8_t *bitmap, size_t index) { return bitmap[index / 8] & (1 << (index % 8)); } static int bitmap_bit_set(uint8_t *bitmap, size_t index) { return bitmap[index / 8] |= (1 << (index % 8)); } /* Convenience functions used to reduce amount of typecasting. */ static void app_compute_hash_wrapper(void *buf, size_t size, void *hash, size_t hash_size) { app_compute_hash(buf, size, hash, hash_size); } static STATE_CLEAR_DATA *get_scd(void) { NV_RESERVED_ITEM ri; NvGetReserved(NV_STATE_CLEAR, &ri); return (STATE_CLEAR_DATA *)((uint8_t *)nvmem_cache_base(NVMEM_TPM) + ri.offset); } /* * Make sure page header hash is different between prod and other types of * images. */ static uint32_t calculate_page_header_hash(struct nn_page_header *ph) { uint32_t hash; static const uint32_t salt[] = {1, 2, 3, 4}; BUILD_ASSERT(sizeof(hash) == offsetof(struct nn_page_header, page_hash)); app_cipher(salt, &hash, ph, sizeof(hash)); return hash; } /* Veirify page header hash. */ static int page_header_is_valid(struct nn_page_header *ph) { return calculate_page_header_hash(ph) == ph->page_hash; } /* Convert flash page number in 0..255 range into actual flash address. */ static struct nn_page_header *flash_index_to_ph(uint8_t index) { return (struct nn_page_header *)((index * CONFIG_FLASH_BANK_SIZE) + CONFIG_PROGRAM_MEMORY_BASE); } static const void *page_cursor(const struct page_tracker *pt) { return (void *)((uintptr_t)pt->ph + pt->data_offset); } /* * Return flash page pointed at by a certain page_list element if the page is * valid. If the index is out of range, or page is not initialized properly * return NULL. */ test_export_static struct nn_page_header *list_element_to_ph(size_t el) { struct nn_page_header *ph; if (el >= ARRAY_SIZE(page_list)) return NULL; ph = flash_index_to_ph(page_list[el]); if (page_header_is_valid(ph)) return ph; return NULL; } /* * Read into buf or skip if buf is NULL the next num_bytes in the storage, at * the location determined by the passed in access tracker. Start from the * very beginning if the passed in access tracker is empty. * * If necessary - concatenate contents from different pages bypassing page * headers. * * If user is reading the container header (as specified by the * container_fetch argument), save in the context the location of the * container. * * If not enough bytes are available in the storage to satisfy the request - * log error and reboot. */ static size_t nvmem_read_bytes(struct access_tracker *at, size_t num_bytes, void *buf, int container_fetch) { size_t togo; struct nvmem_failure_payload fp; if (!at->list_index && !at->mt.data_offset) { /* Start from the beginning. */ at->mt.ph = list_element_to_ph(0); at->mt.data_offset = at->mt.ph->data_offset; } if (container_fetch) { at->ct.data_offset = at->mt.data_offset; at->ct.ph = at->mt.ph; } if ((at->mt.data_offset + num_bytes) < CONFIG_FLASH_BANK_SIZE) { /* * All requested data fits and does not even reach the top of * the page. */ if (buf) memcpy(buf, page_cursor(&at->mt), num_bytes); at->mt.data_offset += num_bytes; return num_bytes; } /* Data is split between pages. */ /* To go in the current page. */ togo = CONFIG_FLASH_BANK_SIZE - at->mt.data_offset; if (buf) { memcpy(buf, page_cursor(&at->mt), togo); /* Next portion goes here. */ buf = (uint8_t *)buf + togo; } /* * Determine how much is there to read in the next page. * * Since object size is limited to page size * less page header size, we are guaranteed that the object would not * span more than one page boundary. */ togo = num_bytes - togo; /* Move to the next page. */ at->list_index++; at->mt.ph = list_element_to_ph(at->list_index); if (!at->mt.ph && togo) { /* * No more data to read. Could the end of used flash be close * to the page boundary, so that there is no room to read an * erased container header? */ if (!container_fetch) { fp.failure_type = NVMEMF_READ_UNDERRUN; fp.underrun_size = num_bytes - togo; /* This will never return. */ report_failure(&fp, sizeof(fp.underrun_size)); } /* * Simulate reading of the container header filled with all * ones, which would be an indication of the end of storage, * the caller will roll back ph, data_offset and list index as * appropriate. */ memset(buf, 0xff, togo); } else if (at->mt.ph) { if (at->mt.ph->data_offset < (sizeof(*at->mt.ph) + togo)) { fp.failure_type = NVMEMF_PH_SIZE_MISMATCH; fp.ph.ph_offset = at->mt.ph->data_offset; fp.ph.expected = sizeof(*at->mt.ph) + togo; /* This will never return. */ report_failure(&fp, sizeof(fp.ph)); } if (buf) memcpy(buf, at->mt.ph + 1, togo); at->mt.data_offset = sizeof(*at->mt.ph) + togo; } return num_bytes; } /* * Convert passed in absolute address into flash memory offset and write the * passed in blob into the flash. */ static enum ec_error_list write_to_flash(const void *flash_addr, const void *obj, size_t size) { return flash_physical_write( (uintptr_t)flash_addr - CONFIG_PROGRAM_MEMORY_BASE, size, obj); } /* * Corrupt headers of all active pages thus invalidating the entire NVMEM * flash storage. */ static void invalidate_nvmem_flash(void) { size_t i; struct nn_page_header *ph; struct nn_page_header bad_ph; memset(&bad_ph, 0, sizeof(bad_ph)); for (i = 0; i < ARRAY_SIZE(page_list); i++) { ph = list_element_to_ph(i); if (!ph) continue; write_to_flash(ph, &bad_ph, sizeof(*ph)); } } /* * When initializing flash for the first time - set the proper first page * header. */ static enum ec_error_list set_first_page_header(void) { struct nn_page_header ph = {}; enum ec_error_list rv; struct nn_page_header *fph; /* Address in flash. */ ph.data_offset = sizeof(ph); ph.page_hash = calculate_page_header_hash(&ph); fph = flash_index_to_ph(page_list[0]); rv = write_to_flash(fph, &ph, sizeof(ph)); if (rv == EC_SUCCESS) { /* Make sure master page tracker is ready. */ memset(&master_at, 0, sizeof(master_at)); master_at.mt.data_offset = ph.data_offset; master_at.mt.ph = fph; } return rv; } /* * Verify that the passed in container is valid, specifically that its hash * matches its contents. */ static int container_is_valid(struct nn_container *ch) { struct nn_container dummy_c; uint32_t hash; uint32_t preserved_hash; uint8_t preserved_type; preserved_hash = ch->container_hash; preserved_type = ch->container_type; ch->container_type = ch->container_type_copy; ch->container_hash = 0; app_compute_hash_wrapper(ch, ch->size + sizeof(*ch), &hash, sizeof(hash)); ch->container_hash = preserved_hash; ch->container_type = preserved_type; dummy_c.container_hash = hash; return dummy_c.container_hash == ch->container_hash; } static uint32_t aligned_container_size(const struct nn_container *ch) { const size_t alignment_mask = CONFIG_FLASH_WRITE_SIZE - 1; return (ch->size + sizeof(*ch) + alignment_mask) & ~alignment_mask; } /* * Function which allows to iterate through all objects stored in flash. The * passed in context keeps track of where the previous object retrieval ended. * * Return: * EC_SUCCESS if an object is retrieved and verified * EC_ERROR_MEMORY_ALLOCATION if 'erased' object reached (not an error). * EC_ERROR_INVAL if verification failed or read is out of sync. */ test_export_static enum ec_error_list get_next_object(struct access_tracker *at, struct nn_container *ch, int include_deleted) { uint32_t salt[4]; uint8_t ctype; salt[3] = 0; do { size_t aligned_remaining_size; struct nn_container temp_ch; nvmem_read_bytes(at, sizeof(temp_ch), &temp_ch, 1); ctype = temp_ch.container_type; /* Should we check for the container being all 0xff? */ if (ctype == NN_OBJ_ERASED) { /* Roll back container size. */ at->mt.data_offset = at->ct.data_offset; at->mt.ph = at->ct.ph; /* * If the container header happened to span between * two pages or end at the page boundary - roll back * page index saved in the context. */ if ((CONFIG_FLASH_BANK_SIZE - at->mt.data_offset) <= sizeof(struct nn_container)) at->list_index--; return EC_ERROR_MEMORY_ALLOCATION; } /* * The read data is a container header, copy it into the user * provided space and continue reading there. */ *ch = temp_ch; aligned_remaining_size = aligned_container_size(ch) - sizeof(*ch); if (aligned_remaining_size) { if (aligned_remaining_size > (CONFIG_FLASH_BANK_SIZE - sizeof(*ch))) { /* Never returns. */ report_no_payload_failure( NVMEMF_INCONSISTENT_FLASH_CONTENTS); } nvmem_read_bytes(at, aligned_remaining_size, ch + 1, 0); salt[0] = at->ct.ph->page_number; salt[1] = at->ct.data_offset; salt[2] = ch->container_hash; /* Decrypt in place. */ if (!app_cipher(salt, ch + 1, ch + 1, ch->size)) report_no_payload_failure(NVMEMF_CIPHER_ERROR); } /* And calculate hash. */ if (!container_is_valid(ch)) { struct nvmem_failure_payload fp; if (!init_in_progress) report_no_payload_failure( NVMEMF_CONTAINER_HASH_MISMATCH); /* * During init there might be a way to deal with * this, let's just log this and continue. */ fp.failure_type = NVMEMF_CONTAINER_HASH_MISMATCH; flash_log_add_event( FE_LOG_NVMEM, offsetof(struct nvmem_failure_payload, size), &fp); return EC_ERROR_INVAL; } /* * Keep track of the most recently encountered delimiter, * finalized or not. */ if (ch->container_type_copy == NN_OBJ_TRANSACTION_DEL) { include_deleted = 1; /* Always return all delimiters. */ /* But keep track only of finalized ones. */ if (ch->container_type == NN_OBJ_OLD_COPY) { at->dt.ph = at->ct.ph; at->dt.data_offset = at->ct.data_offset; } } } while (!include_deleted && (ctype == NN_OBJ_OLD_COPY)); return EC_SUCCESS; } /* * Add a delimiter object at the top of the flash. The container type field is * not erased. * * This is an indication that after nvmem_commit() invocation all updated * objects have been saved in the flash, but the old instances of the objects * have not yet been deleted. */ static enum ec_error_list add_delimiter(void) { struct nn_container ch; memset(&ch, 0, sizeof(ch)); ch.container_type = ch.container_type_copy = NN_OBJ_TRANSACTION_DEL; return save_container(&ch); } /* * Erase the container type field of the previously saved delimiter, thus * indicating that nvmem save transaction is completed. */ static enum ec_error_list finalize_delimiter(const struct nn_container *del) { struct nn_container c; c = *del; c.container_type = NN_OBJ_OLD_COPY; return write_to_flash(del, &c, sizeof(c)); } /* Add delimiter indicating that flash is in a consistent state. */ static enum ec_error_list add_final_delimiter(void) { const struct nn_container *del; del = page_cursor(&master_at.mt); add_delimiter(); return finalize_delimiter(del); } /* Erase flash page and add it to the pool of empty pages. */ static void release_flash_page(struct access_tracker *at) { uint8_t page_index = page_list[0]; void *flash; flash = flash_index_to_ph(page_index); flash_physical_erase((uintptr_t)flash - CONFIG_PROGRAM_MEMORY_BASE, CONFIG_FLASH_BANK_SIZE); memmove(page_list, page_list + 1, (ARRAY_SIZE(page_list) - 1) * sizeof(page_list[0])); page_list[ARRAY_SIZE(page_list) - 1] = page_index; at->list_index--; master_at.list_index--; } /* Reshuffle flash contents dropping deleted objects. */ test_export_static enum ec_error_list compact_nvmem(void) { const void *fence_ph; enum ec_error_list rv = EC_SUCCESS; size_t before; struct nn_container *ch; struct access_tracker at = {}; int saved_object_count; int final_delimiter_needed = 1; /* How much space was used before compaction. */ before = total_used_size(); /* One page is enough even for the largest object. */ ch = get_scratch_buffer(CONFIG_FLASH_BANK_SIZE); /* * Page where we should stop compaction, all pages before this would * be recycled. */ fence_ph = master_at.mt.ph; saved_object_count = 0; do { switch (get_next_object(&at, ch, 0)) { case EC_SUCCESS: break; case EC_ERROR_MEMORY_ALLOCATION: shared_mem_release(ch); return EC_SUCCESS; default: /* * The error has been reported already. * * This must be compaction after startup with * inconsistent nvmemory state, let's make sure the * top page is recycled. */ if (at.mt.ph != fence_ph) release_flash_page(&at); shared_mem_release(ch); return EC_ERROR_INVAL; } /* Re-store the object in compacted flash. */ switch (ch->container_type) { case NN_OBJ_TUPLE: case NN_OBJ_TPM_RESERVED: case NN_OBJ_TPM_EVICTABLE: ch->generation++; if (save_container(ch) != EC_SUCCESS) { ccprintf("%s: Saving FAILED\n", __func__); shared_mem_release(ch); return EC_ERROR_INVAL; } saved_object_count++; break; default: break; } if (at.list_index != 0) { /* * We are done with a pre-compaction page, use a * delimiter to indicate that a bunch of objects are * being deleted and finalize the delimiter once the * old page is erased. * * Return the erased page to the pool of empty pages * and rearrange the list of active pages. */ const void *del; if (saved_object_count) { del = page_cursor(&master_at.mt); add_delimiter(); } release_flash_page(&at); #if defined(NVMEM_TEST_BUILD) if (failure_mode == TEST_FAIL_WHEN_COMPACTING) { shared_mem_release(ch); return EC_SUCCESS; } #endif if (saved_object_count) { finalize_delimiter(del); saved_object_count = 0; } /* * No need in another delimiter if data ends on a page * boundary. */ final_delimiter_needed = 0; } else { final_delimiter_needed = 1; } } while (at.mt.ph != fence_ph); shared_mem_release(ch); if (final_delimiter_needed) add_final_delimiter(); CPRINTS("Compaction done, went from %zd to %zd bytes", before, total_used_size()); return rv; } static void start_new_flash_page(size_t data_size) { struct nn_page_header ph = {}; ph.data_offset = sizeof(ph) + data_size; ph.page_number = master_at.mt.ph->page_number + 1; ph.page_hash = calculate_page_header_hash(&ph); master_at.list_index++; if (master_at.list_index == ARRAY_SIZE(page_list)) report_no_payload_failure(NVMEMF_PAGE_LIST_OVERFLOW); master_at.mt.ph = (const void *)(((uintptr_t)page_list[master_at.list_index] * CONFIG_FLASH_BANK_SIZE) + CONFIG_PROGRAM_MEMORY_BASE); write_to_flash(master_at.mt.ph, &ph, sizeof(ph)); master_at.mt.data_offset = sizeof(ph); } /* * Save in the flash an object represented by the passed in container. Add new * pages to the list of used pages if necessary. */ static enum ec_error_list save_object(const struct nn_container *cont) { const void *save_data = cont; size_t save_size = aligned_container_size(cont); size_t top_room; #if defined(NVMEM_TEST_BUILD) if (failure_mode == TEST_FAILED_HASH) save_size -= sizeof(uint32_t); #endif top_room = CONFIG_FLASH_BANK_SIZE - master_at.mt.data_offset; if (save_size >= top_room) { /* Let's finish the current page. */ write_to_flash((uint8_t *)master_at.mt.ph + master_at.mt.data_offset, cont, top_room); /* Remaining data and size to be written on the next page. */ save_data = (const void *)((uintptr_t)save_data + top_room); save_size -= top_room; start_new_flash_page(save_size); #if defined(NVMEM_TEST_BUILD) if (save_size && (failure_mode == TEST_SPANNING_PAGES)) { ccprintf("%s:%d corrupting...\n", __func__, __LINE__); return EC_SUCCESS; } #endif } if (save_size) { write_to_flash((uint8_t *)master_at.mt.ph + master_at.mt.data_offset, save_data, save_size); master_at.mt.data_offset += save_size; } return EC_SUCCESS; } /* * Functions to check if the passed in blob is all zeros or all 0xff, in both * cases would be considered an uninitialized value. This is used when * marshaling certaing structures and PCRs. */ static int is_all_value(const uint8_t *p, size_t size, uint8_t value) { size_t i; for (i = 0; i < size; i++) if (p[i] != value) return 0; return 1; } test_export_static int is_uninitialized(const void *p, size_t size) { return is_all_value(p, size, 0xff); } static int is_all_zero(const void *p, size_t size) { return is_all_value(p, size, 0); } static int is_empty(const void *pcr_base, size_t pcr_size) { return is_uninitialized(pcr_base, pcr_size) || is_all_zero(pcr_base, pcr_size); } /* * A convenience function checking if the passed in blob is not empty, and if * so - save the blob in the destination memory. * * Return number of bytes placed in dst or zero, if the blob was empty. */ static size_t copy_pcr(const uint8_t *pcr_base, size_t pcr_size, uint8_t *dst) { /* * We rely on the fact that all 16 PCRs of every PCR bank saved in the * NVMEM's reserved space are originally set to all zeros. * * If all 0xFF is read - this is considered an artifact of trying to * retrieve PCRs from legacy flash snapshot from the state when PCRs * were not saved in the reserved space at all, i.e. also indicates an * empty PCR. */ if (is_empty(pcr_base, pcr_size)) return 0; /* No need to save this. */ memcpy(dst, pcr_base, pcr_size); return pcr_size; } /* * A convenience structure and array, allowing quick access to PCR banks * contained in the STATE_CLEAR_DATA:pcrSave field. This helps when * marshailing/unmarshaling PCR contents. */ struct pcr_descriptor { uint16_t pcr_array_offset; uint8_t pcr_size; } __packed; static const struct pcr_descriptor pcr_arrays[] = { {offsetof(PCR_SAVE, sha1), SHA1_DIGEST_SIZE}, {offsetof(PCR_SAVE, sha256), SHA256_DIGEST_SIZE}, {offsetof(PCR_SAVE, sha384), SHA384_DIGEST_SIZE}, {offsetof(PCR_SAVE, sha512), SHA512_DIGEST_SIZE} }; #define NUM_OF_PCRS (ARRAY_SIZE(pcr_arrays) * NUM_STATIC_PCR) /* Just in case we ever get to reducing the PCR set one way or another. */ BUILD_ASSERT(ARRAY_SIZE(pcr_arrays) == 4); BUILD_ASSERT(NUM_OF_PCRS == 64); /* * Iterate over PCRs contained in the STATE_CLEAR_DATA structure in the NVMEM * cache and save nonempty ones in the flash. */ static void migrate_pcr(STATE_CLEAR_DATA *scd, size_t array_index, size_t pcr_index, struct nn_container *ch) { const struct pcr_descriptor *pdsc; uint8_t *p_container_body; uint8_t *pcr_base; uint8_t reserved_index; /* Unique ID of this PCR in reserved storage. */ p_container_body = (uint8_t *)(ch + 1); pdsc = pcr_arrays + array_index; pcr_base = (uint8_t *)&scd->pcrSave + pdsc->pcr_array_offset + pdsc->pcr_size * pcr_index; reserved_index = NV_VIRTUAL_RESERVE_LAST + array_index * NUM_STATIC_PCR + pcr_index; if (!copy_pcr(pcr_base, pdsc->pcr_size, p_container_body + 1)) return; p_container_body[0] = reserved_index; ch->size = pdsc->pcr_size + 1; save_container(ch); } /* * Some NVMEM structures end up in the NVMEM cache with a wrong alignment. If * a passed in pointer is not aligned at a 4 byte boundary, this function will * save the 4 bytes above the blob in the passed in space and then move the * blob up so that it is properly aligned. */ static void *preserve_struct(void *p, size_t size, uint32_t *preserved) { uint32_t misalignment = ((uintptr_t)p & 3); void *new_p; if (!misalignment) return p; /* Nothing to adjust. */ memcpy(preserved, (uint8_t *)p + size, sizeof(*preserved)); new_p = (void *)((((uintptr_t)p) + 3) & ~3); memmove(new_p, p, size); return new_p; } static void maybe_restore_struct(void *new_p, void *old_p, size_t size, uint32_t *preserved) { if (!memcmp(new_p, old_p, size)) return; memmove(old_p, new_p, size); memcpy((uint8_t *)old_p + size, preserved, sizeof(*preserved)); } /* * Note that PCRs are not marshaled here, but the rest of the structre, below * and above the PCR array is. */ static uint16_t marshal_state_clear(STATE_CLEAR_DATA *scd, uint8_t *dst) { PCR_AUTHVALUE *new_pav; STATE_CLEAR_DATA *new_scd; size_t bottom_size; size_t i; size_t top_size; uint32_t preserved; uint8_t *base; int room; bottom_size = offsetof(STATE_CLEAR_DATA, pcrSave); top_size = sizeof(scd->pcrAuthValues); if (is_empty(scd, bottom_size) && is_empty(&scd->pcrAuthValues, top_size) && is_empty(&scd->pcrSave.pcrCounter, sizeof(scd->pcrSave.pcrCounter))) return 0; /* Marshaling STATE_CLEAR_DATA will never need this much. */ room = CONFIG_FLASH_BANK_SIZE; new_scd = preserve_struct(scd, bottom_size, &preserved); base = dst; *dst++ = (!!new_scd->shEnable) | ((!!new_scd->ehEnable) << 1) | ((!!new_scd->phEnableNV) << 2); memcpy(dst, &new_scd->platformAlg, sizeof(new_scd->platformAlg)); dst += sizeof(new_scd->platformAlg); room -= (dst - base); TPM2B_DIGEST_Marshal(&new_scd->platformPolicy, &dst, &room); TPM2B_AUTH_Marshal(&new_scd->platformAuth, &dst, &room); memcpy(dst, &new_scd->pcrSave.pcrCounter, sizeof(new_scd->pcrSave.pcrCounter)); dst += sizeof(new_scd->pcrSave.pcrCounter); room -= sizeof(new_scd->pcrSave.pcrCounter); maybe_restore_struct(new_scd, scd, bottom_size, &preserved); new_pav = preserve_struct(&scd->pcrAuthValues, top_size, &preserved); for (i = 0; i < ARRAY_SIZE(new_scd->pcrAuthValues.auth); i++) TPM2B_DIGEST_Marshal(new_pav->auth + i, &dst, &room); maybe_restore_struct(new_pav, &scd->pcrAuthValues, top_size, &preserved); return dst - base; } static uint16_t marshal_state_reset_data(STATE_RESET_DATA *srd, uint8_t *dst) { STATE_RESET_DATA *new_srd; uint32_t preserved; uint8_t *base; int room; if (is_empty(srd, sizeof(*srd))) return 0; /* Marshaling STATE_RESET_DATA will never need this much. */ room = CONFIG_FLASH_BANK_SIZE; new_srd = preserve_struct(srd, sizeof(*srd), &preserved); base = dst; TPM2B_AUTH_Marshal(&new_srd->nullProof, &dst, &room); TPM2B_DIGEST_Marshal((TPM2B_DIGEST *)(&new_srd->nullSeed), &dst, &room); UINT32_Marshal(&new_srd->clearCount, &dst, &room); UINT64_Marshal(&new_srd->objectContextID, &dst, &room); memcpy(dst, new_srd->contextArray, sizeof(new_srd->contextArray)); room -= sizeof(new_srd->contextArray); dst += sizeof(new_srd->contextArray); memcpy(dst, &new_srd->contextCounter, sizeof(new_srd->contextCounter)); room -= sizeof(new_srd->contextCounter); dst += sizeof(new_srd->contextCounter); TPM2B_DIGEST_Marshal(&new_srd->commandAuditDigest, &dst, &room); UINT32_Marshal(&new_srd->restartCount, &dst, &room); UINT32_Marshal(&new_srd->pcrCounter, &dst, &room); #ifdef TPM_ALG_ECC UINT64_Marshal(&new_srd->commitCounter, &dst, &room); TPM2B_NONCE_Marshal(&new_srd->commitNonce, &dst, &room); memcpy(dst, new_srd->commitArray, sizeof(new_srd->commitArray)); room -= sizeof(new_srd->commitArray); dst += sizeof(new_srd->commitArray); #endif maybe_restore_struct(new_srd, srd, sizeof(*srd), &preserved); return dst - base; } /* * Migrate all reserved objects found in the NVMEM cache after intializing * from legacy NVMEM storage. */ static enum ec_error_list migrate_tpm_reserved(struct nn_container *ch) { STATE_CLEAR_DATA *scd = NULL; STATE_RESET_DATA *srd; size_t pcr_type_index; uint8_t *p_tpm_nvmem = nvmem_cache_base(NVMEM_TPM); uint8_t *p_container_body = (uint8_t *)(ch + 1); uint8_t index; ch->container_type = ch->container_type_copy = NN_OBJ_TPM_RESERVED; for (index = 0; index < NV_VIRTUAL_RESERVE_LAST; index++) { NV_RESERVED_ITEM ri; int copy_needed = 1; NvGetReserved(index, &ri); p_container_body[0] = index; switch (index) { case NV_STATE_CLEAR: scd = (STATE_CLEAR_DATA *)(p_tpm_nvmem + ri.offset); ri.size = marshal_state_clear(scd, p_container_body + 1); copy_needed = 0; break; case NV_STATE_RESET: srd = (STATE_RESET_DATA *)(p_tpm_nvmem + ri.offset); ri.size = marshal_state_reset_data( srd, p_container_body + 1); copy_needed = 0; break; } if (copy_needed) { /* * Copy data into the stage area unless already done * by marshaling function above. */ memcpy(p_container_body + 1, p_tpm_nvmem + ri.offset, ri.size); } ch->size = ri.size + 1; save_container(ch); } /* * Now all components but the PCRs from STATE_CLEAR_DATA have been * saved, let's deal with those PCR arrays. We want to save each PCR * in a separate container, as if all PCRs are extended, the total * combined size of the arrays would exceed flash page size. Also, * PCRs are most likely to change one or very few at a time. */ for (pcr_type_index = 0; pcr_type_index < ARRAY_SIZE(pcr_arrays); pcr_type_index++) { size_t pcr_index; for (pcr_index = 0; pcr_index < NUM_STATIC_PCR; pcr_index++) migrate_pcr(scd, pcr_type_index, pcr_index, ch); } return EC_SUCCESS; } /* * Migrate all evictable objects found in the NVMEM cache after intializing * from legacy NVMEM storage. */ static enum ec_error_list migrate_objects(struct nn_container *ch) { uint32_t next_obj_base; uint32_t obj_base; uint32_t obj_size; void *obj_addr; ch->container_type = ch->container_type_copy = NN_OBJ_TPM_EVICTABLE; obj_base = s_evictNvStart; obj_addr = nvmem_cache_base(NVMEM_TPM) + obj_base; memcpy(&next_obj_base, obj_addr, sizeof(next_obj_base)); while (next_obj_base && (next_obj_base <= s_evictNvEnd)) { obj_size = next_obj_base - obj_base - sizeof(obj_size); memcpy(ch + 1, (uint32_t *)obj_addr + 1, obj_size); ch->size = obj_size; save_container(ch); obj_base = next_obj_base; obj_addr = nvmem_cache_base(NVMEM_TPM) + obj_base; memcpy(&next_obj_base, obj_addr, sizeof(next_obj_base)); } return EC_SUCCESS; } static enum ec_error_list migrate_tpm_nvmem(struct nn_container *ch) { /* Call this to initialize NVMEM indices. */ NvEarlyStageFindHandle(0); migrate_tpm_reserved(ch); migrate_objects(ch); return EC_SUCCESS; } static enum ec_error_list save_var(const uint8_t *key, uint8_t key_len, const uint8_t *val, uint8_t val_len, struct max_var_container *vc) { const int total_size = key_len + val_len + offsetof(struct max_var_container, body); enum ec_error_list rv; int local_alloc = !vc; if (local_alloc) { vc = get_scratch_buffer(total_size); vc->c_header.generation = 0; } /* Fill up tuple body. */ vc->t_header.key_len = key_len; vc->t_header.val_len = val_len; memcpy(vc->body, key, key_len); memcpy(vc->body + key_len, val, val_len); /* Set up container header. */ vc->c_header.container_type_copy = vc->c_header.container_type = NN_OBJ_TUPLE; vc->c_header.encrypted = 1; vc->c_header.size = sizeof(struct tuple) + val_len + key_len; rv = save_container(&vc->c_header); if (rv == EC_SUCCESS) total_var_space += key_len + val_len; if (local_alloc) shared_mem_release(vc); return rv; } /* * Migrate all (key, value) pairs found in the NVMEM cache after intializing * from legacy NVMEM storage. */ static enum ec_error_list migrate_vars(struct nn_container *ch) { const struct tuple *var; /* * During migration (key, value) pairs need to be manually copied from * the NVMEM cache. */ set_local_copy(); var = NULL; total_var_space = 0; while ((var = legacy_getnextvar(var)) != NULL) save_var(var->data_, var->key_len, var->data_ + var->key_len, var->val_len, (struct max_var_container *)ch); return EC_SUCCESS; } static int erase_partition(unsigned int act_partition, int erase_backup) { enum ec_error_list rv; size_t flash_base; /* * This is the first time we save using the new scheme, let's prepare * the flash space. First determine which half is the backup now and * erase it. */ flash_base = (act_partition ^ erase_backup) ? CONFIG_FLASH_NVMEM_BASE_A : CONFIG_FLASH_NVMEM_BASE_B; flash_base -= CONFIG_PROGRAM_MEMORY_BASE; rv = flash_physical_erase(flash_base, NVMEM_PARTITION_SIZE); if (rv != EC_SUCCESS) { ccprintf("%s: flash erase failed\n", __func__); return -rv; } return flash_base + CONFIG_FLASH_BANK_SIZE; } /* * This function is called once in a lifetime, when Cr50 boots up and a legacy * partition if found in the flash. */ enum ec_error_list new_nvmem_migrate(unsigned int act_partition) { int flash_base; int i; int j; struct nn_container *ch; if (!crypto_enabled()) return EC_ERROR_INVAL; /* * This is the first time we save using the new scheme, let's prepare * the flash space. First determine which half is the backup now and * erase it. */ flash_base = erase_partition(act_partition, 1); if (flash_base < 0) { ccprintf("%s: backup partition erase failed\n", __func__); return -flash_base; } ch = get_scratch_buffer(CONFIG_FLASH_BANK_SIZE); lock_mutex(__LINE__); /* Populate half of page_list with available page offsets. */ for (i = 0; i < ARRAY_SIZE(page_list) / 2; i++) page_list[i] = flash_base / CONFIG_FLASH_BANK_SIZE + i; set_first_page_header(); ch->encrypted = 1; ch->generation = 0; migrate_vars(ch); migrate_tpm_nvmem(ch); shared_mem_release(ch); add_final_delimiter(); unlock_mutex(__LINE__); if (browse_flash_contents(0) != EC_SUCCESS) /* Never returns. */ report_no_payload_failure(NVMEMF_MIGRATION_FAILURE); CPRINTS("Migration success, used %zd bytes of flash", total_used_size()); /* * Now we can erase the active partition and add its flash to the pool. */ flash_base = erase_partition(act_partition, 0); if (flash_base < 0) /* Never returns. */ report_no_payload_failure(NVMEMF_LEGACY_ERASE_FAILURE); /* * Populate the second half of the page_list with pages retrieved from * legacy partition. */ for (j = 0; j < ARRAY_SIZE(page_list) / 2; j++) page_list[i + j] = flash_base / CONFIG_FLASH_BANK_SIZE + j; return EC_SUCCESS; } /* Check if the passed in flash page is empty, if not - erase it. */ static void verify_empty_page(void *ph) { uint32_t *word_p = ph; size_t i; for (i = 0; i < (CONFIG_FLASH_BANK_SIZE / sizeof(*word_p)); i++) { if (word_p[i] != (uint32_t)~0) { CPRINTS("%s: corrupted page at %pP!", __func__, word_p); flash_physical_erase((uintptr_t)word_p - CONFIG_PROGRAM_MEMORY_BASE, CONFIG_FLASH_BANK_SIZE); break; } } } /* * At startup initialize the list of pages which contain NVMEM data and erased * pages. The list (in fact an array containing indices of the pages) is * sorted by the page number found in the page header. Pages which do not * contain valid page header are checked to be erased and are placed at the * tail of the list. */ static void init_page_list(void) { size_t i; size_t j; size_t page_list_index = 0; size_t tail_index; struct nn_page_header *ph; tail_index = ARRAY_SIZE(page_list); for (i = 0; i < ARRAY_SIZE(page_list); i++) { uint32_t page_index; /* * This will yield indices of top pages first, first from the * bottom half of the flash, and then from the top half. We * know that flash is 512K in size, and pages are 2K in size, * the indices will be in 123..127 and 251..255 range. */ if (i < (ARRAY_SIZE(page_list) / 2)) { page_index = (CONFIG_FLASH_NEW_NVMEM_BASE_A - CONFIG_PROGRAM_MEMORY_BASE) / CONFIG_FLASH_BANK_SIZE + i; } else { page_index = (CONFIG_FLASH_NEW_NVMEM_BASE_B - CONFIG_PROGRAM_MEMORY_BASE) / CONFIG_FLASH_BANK_SIZE - ARRAY_SIZE(page_list) / 2 + i; } ph = flash_index_to_ph(page_index); if (!page_header_is_valid(ph)) { /* * this is not a valid page, let's plug it in into the * tail of the list. */ page_list[--tail_index] = page_index; verify_empty_page(ph); continue; } /* This seems a valid page, let's put it in order. */ for (j = 0; j < page_list_index; j++) { struct nn_page_header *prev_ph; prev_ph = list_element_to_ph(j); if (prev_ph->page_number > ph->page_number) { /* Need to move up. */ memmove(page_list + j + 1, page_list + j, sizeof(page_list[0]) * (page_list_index - j)); break; } } page_list[j] = page_index; page_list_index++; } if (!page_list_index) { CPRINTS("Init nvmem from scratch"); set_first_page_header(); page_list_index++; } } /* * The passed in pointer contains marshaled STATE_CLEAR structure as retrieved * from flash. This function unmarshals it and places in the NVMEM cache where * it belongs. Note that PCRs were not marshaled. */ static void unmarshal_state_clear(uint8_t *pad, int size, uint32_t offset) { STATE_CLEAR_DATA *real_scd; STATE_CLEAR_DATA *scd; size_t i; uint32_t preserved; uint8_t booleans; real_scd = (STATE_CLEAR_DATA *)((uint8_t *)nvmem_cache_base(NVMEM_TPM) + offset); memset(real_scd, 0, sizeof(*real_scd)); if (!size) return; memcpy(&preserved, real_scd + 1, sizeof(preserved)); scd = (void *)(((uintptr_t)real_scd + 3) & ~3); /* Need proper unmarshal. */ booleans = *pad++; scd->shEnable = !!(booleans & 1); scd->ehEnable = !!(booleans & (1 << 1)); scd->phEnableNV = !!(booleans & (1 << 2)); size--; memcpy(&scd->platformAlg, pad, sizeof(scd->platformAlg)); pad += sizeof(scd->platformAlg); size -= sizeof(scd->platformAlg); TPM2B_DIGEST_Unmarshal(&scd->platformPolicy, &pad, &size); TPM2B_AUTH_Unmarshal(&scd->platformAuth, &pad, &size); memcpy(&scd->pcrSave.pcrCounter, pad, sizeof(scd->pcrSave.pcrCounter)); pad += sizeof(scd->pcrSave.pcrCounter); size -= sizeof(scd->pcrSave.pcrCounter); for (i = 0; i < ARRAY_SIZE(scd->pcrAuthValues.auth); i++) TPM2B_DIGEST_Unmarshal(scd->pcrAuthValues.auth + i, &pad, &size); memmove(real_scd, scd, sizeof(*scd)); memcpy(real_scd + 1, &preserved, sizeof(preserved)); } /* * The passed in pointer contains marshaled STATE_RESET structure as retrieved * from flash. This function unmarshals it and places in the NVMEM cache where * it belongs. */ static void unmarshal_state_reset(uint8_t *pad, int size, uint32_t offset) { STATE_RESET_DATA *real_srd; STATE_RESET_DATA *srd; uint32_t preserved; real_srd = (STATE_RESET_DATA *)((uint8_t *)nvmem_cache_base(NVMEM_TPM) + offset); memset(real_srd, 0, sizeof(*real_srd)); if (!size) return; memcpy(&preserved, real_srd + 1, sizeof(preserved)); srd = (void *)(((uintptr_t)real_srd + 3) & ~3); TPM2B_AUTH_Unmarshal(&srd->nullProof, &pad, &size); TPM2B_DIGEST_Unmarshal((TPM2B_DIGEST *)(&srd->nullSeed), &pad, &size); UINT32_Unmarshal(&srd->clearCount, &pad, &size); UINT64_Marshal(&srd->objectContextID, &pad, &size); memcpy(srd->contextArray, pad, sizeof(srd->contextArray)); size -= sizeof(srd->contextArray); pad += sizeof(srd->contextArray); memcpy(&srd->contextCounter, pad, sizeof(srd->contextCounter)); size -= sizeof(srd->contextCounter); pad += sizeof(srd->contextCounter); TPM2B_DIGEST_Unmarshal(&srd->commandAuditDigest, &pad, &size); UINT32_Unmarshal(&srd->restartCount, &pad, &size); UINT32_Unmarshal(&srd->pcrCounter, &pad, &size); #ifdef TPM_ALG_ECC UINT64_Unmarshal(&srd->commitCounter, &pad, &size); TPM2B_NONCE_Unmarshal(&srd->commitNonce, &pad, &size); memcpy(srd->commitArray, pad, sizeof(srd->commitArray)); size -= sizeof(srd->commitArray); #endif memmove(real_srd, srd, sizeof(*srd)); memcpy(real_srd + 1, &preserved, sizeof(preserved)); } /* * Based on the passed in index, find the location of the PCR in the NVMEM * cache and copy it there. */ static void restore_pcr(size_t pcr_index, uint8_t *pad, size_t size) { const STATE_CLEAR_DATA *scd; const struct pcr_descriptor *pcrd; void *cached; /* This PCR's position in the NVMEM cache. */ if (pcr_index > NUM_OF_PCRS) return; /* This is an error. */ pcrd = pcr_arrays + pcr_index / NUM_STATIC_PCR; if (pcrd->pcr_size != size) return; /* This is an error. */ scd = get_scd(); cached = (uint8_t *)&scd->pcrSave + pcrd->pcr_array_offset + pcrd->pcr_size * (pcr_index % NUM_STATIC_PCR); memcpy(cached, pad, size); } /* Restore a reserved object found in flash on initialization. */ static void restore_reserved(void *pad, size_t size, uint8_t *bitmap) { NV_RESERVED_ITEM ri; uint16_t type; void *cached; /* * Index is saved as a single byte, update pad to point at the * payload. */ type = *(uint8_t *)pad++; size--; if (type < NV_VIRTUAL_RESERVE_LAST) { NvGetReserved(type, &ri); bitmap_bit_set(bitmap, type); switch (type) { case NV_STATE_CLEAR: unmarshal_state_clear(pad, size, ri.offset); break; case NV_STATE_RESET: unmarshal_state_reset(pad, size, ri.offset); break; default: cached = ((uint8_t *)nvmem_cache_base(NVMEM_TPM) + ri.offset); memcpy(cached, pad, size); break; } return; } restore_pcr(type - NV_VIRTUAL_RESERVE_LAST, pad, size); } /* Restore an evictable object found in flash on initialization. */ static void restore_object(void *pad, size_t size) { uint8_t *dest; if (!next_evict_obj_base) next_evict_obj_base = s_evictNvStart; dest = ((uint8_t *)nvmem_cache_base(NVMEM_TPM) + next_evict_obj_base); next_evict_obj_base += size + sizeof(next_evict_obj_base); memcpy(dest, &next_evict_obj_base, sizeof(next_evict_obj_base)); dest += sizeof(next_evict_obj_base); memcpy(dest, pad, size); dest += size; memset(dest, 0, sizeof(next_evict_obj_base)); } /* * When starting from scratch (flash fully erased) there would be no reserved * objects in NVMEM, and for the commit to work properly, every single * reserved object needs to be present in the flash so that its value is * compared with the cache contents. * * There is also an off chance of a bug where a reserved value is lost in the * flash - it would never be reinstated even after TPM reinitializes. * * The reserved_bitmap array is a bitmap of all detected reserved objects, * those not in the array are initialized to a dummy initial value. */ static enum ec_error_list verify_reserved(uint8_t *reserved_bitmap, struct nn_container *ch) { enum ec_error_list rv; int i; uint8_t *container_body; int delimiter_needed = 0; /* All uninitted reserved objects set to zero. */ memset(ch, 0, CONFIG_FLASH_BANK_SIZE); ch->container_type = ch->container_type_copy = NN_OBJ_TPM_RESERVED; ch->encrypted = 1; container_body = (uint8_t *)(ch + 1); rv = EC_SUCCESS; for (i = 0; i < NV_VIRTUAL_RESERVE_LAST; i++) { NV_RESERVED_ITEM ri; if (bitmap_bit_check(reserved_bitmap, i)) continue; NvGetReserved(i, &ri); container_body[0] = i; switch (i) { /* * No need to save these on initialization from * scratch, unmarshaling code will properly expand * size of zero. */ case NV_STATE_CLEAR: case NV_STATE_RESET: ri.size = 0; break; /* * This is used for Ram Index field, prepended by * size. Set the size to minimum, the size of the size * field. */ case NV_RAM_INDEX_SPACE: ri.size = sizeof(uint32_t); break; default: break; } delimiter_needed = 1; ch->size = ri.size + 1; rv = save_container(ch); /* Clean up encrypted contents. */ memset(container_body + 1, 0, ri.size); if (rv != EC_SUCCESS) break; } if (delimiter_needed && (rv == EC_SUCCESS)) add_final_delimiter(); return rv; } static enum ec_error_list invalidate_object(const struct nn_container *ch) { struct nn_container c_copy; c_copy = *ch; c_copy.container_type = NN_OBJ_OLD_COPY; return write_to_flash(ch, &c_copy, sizeof(uint32_t)); } static enum ec_error_list delete_object(const struct access_tracker *at, struct nn_container *ch) { const void *flash_ch; flash_ch = page_cursor(&at->ct); if (memcmp(ch, flash_ch, sizeof(uint32_t))) report_no_payload_failure(NVMEMF_PRE_ERASE_MISMATCH); if (!del_candidates) return invalidate_object(flash_ch); /* * Do not delete the object yet, save it in the list of delete * candidates. */ if (del_candidates->num_candidates == ARRAY_SIZE(del_candidates->candidates)) report_no_payload_failure(NVMEMF_EXCESS_DELETE_OBJECTS); del_candidates->candidates[del_candidates->num_candidates++] = flash_ch; return EC_SUCCESS; } static enum ec_error_list verify_last_section( const struct page_tracker *prev_del, struct nn_container *ch) { /* * This is very inefficient, but we do this only when recovering from * botched nvmem saves. * * For each object found between prev_del and last_del we need to * check if there are earlier instances of these objects in the flash * which are not yet deleted, and delete them if found. */ struct object { uint8_t cont_type; union { uint32_t handle; /* For evictables. */ uint8_t id; /* For reserved objects. */ struct { /* For tuples. */ uint32_t key_hash; uint8_t key_len; }; }; }; struct new_objects { uint8_t num_objects; struct object objects[2 * MAX_DELETE_CANDIDATES]; }; struct access_tracker at; struct new_objects *newobjs; struct object *po; uint8_t ctype; struct page_tracker top_del; struct max_var_container *vc; int i; newobjs = get_scratch_buffer(sizeof(struct new_objects)); at.mt = *prev_del; for (i = 0; i < ARRAY_SIZE(page_list); i++) if (list_element_to_ph(i) == at.mt.ph) { at.list_index = i; break; } po = newobjs->objects; while (get_next_object(&at, ch, 0) == EC_SUCCESS) { ctype = ch->container_type; /* Speculative assignment, might be unused. */ po->cont_type = ctype; switch (ctype) { case NN_OBJ_TPM_RESERVED: po->id = *((uint8_t *)(ch + 1)); break; case NN_OBJ_TPM_EVICTABLE: po->handle = *((uint32_t *)(ch + 1)); break; case NN_OBJ_TUPLE: vc = (struct max_var_container *)ch; po->key_len = vc->t_header.key_len; app_compute_hash_wrapper(vc->t_header.data_, po->key_len, &po->key_hash, sizeof(po->key_hash)); break; default: continue; } if (++(newobjs->num_objects) == ARRAY_SIZE(newobjs->objects)) /* Never returns. */ report_no_payload_failure(NVMEMF_SECTION_VERIFY); po++; } /* * Last object read from flash should have been a non-finalized * delimiter. */ if (ch->container_type != NN_OBJ_TRANSACTION_DEL) { struct nvmem_failure_payload fp; fp.failure_type = NVMEMF_UNEXPECTED_LAST_OBJ; fp.last_obj_type = ch->container_type; /* Never returns. */ report_failure(&fp, sizeof(fp.last_obj_type)); } /* * Now we have a cache of of objects which were updated but their old * instances could have been left in the flash. Let's iterate over the * flash and delete those if found. */ memset(&at, 0, sizeof(at)); while ((at.mt.ph != prev_del->ph) && (at.mt.data_offset != prev_del->data_offset)) { size_t i; size_t key_size; uint32_t key; if (get_next_object(&at, ch, 0) != EC_SUCCESS) report_no_payload_failure(NVMEMF_MISSING_OBJECT); ctype = ch->container_type; switch (ctype) { case NN_OBJ_TPM_RESERVED: key = *((uint8_t *)(ch + 1)); key_size = sizeof(uint8_t); break; case NN_OBJ_TPM_EVICTABLE: key = *((uint32_t *)(ch + 1)); key_size = sizeof(uint32_t); break; case NN_OBJ_TUPLE: vc = (struct max_var_container *)ch; key_size = vc->t_header.key_len; app_compute_hash_wrapper(vc->t_header.data_, key_size, &key, sizeof(key)); break; default: continue; } for (i = 0, po = newobjs->objects; i < newobjs->num_objects; i++, po++) { if (po->cont_type != ctype) continue; if ((ctype == NN_OBJ_TPM_RESERVED) && (po->id != key)) continue; if ((ctype == NN_OBJ_TPM_EVICTABLE) && (po->handle != key)) continue; if ((ctype == NN_OBJ_TUPLE) && ((po->key_len != key_size) || (key != po->key_hash))) continue; /* * This indeed is a leftover which needs to be * deleted. */ delete_object(&at, ch); } } shared_mem_release(newobjs); if (master_at.mt.data_offset > sizeof(struct nn_page_header)) { top_del.ph = master_at.mt.ph; top_del.data_offset = master_at.mt.data_offset - sizeof(struct nn_container); } else { top_del.ph = list_element_to_ph(master_at.list_index - 1); top_del.data_offset = CONFIG_FLASH_BANK_SIZE - -sizeof(struct nn_container); } return finalize_delimiter(page_cursor(&top_del)); } /* * This function is called during initialization after the entire flash * contents were scanned, to verify that flash is in a valid state. */ static enum ec_error_list verify_delimiter(struct nn_container *nc) { enum ec_error_list rv; /* Used to read starting at last good delimiter. */ struct access_tracker dpt = {}; if ((master_at.list_index == 0) && (master_at.mt.data_offset == sizeof(struct nn_page_header))) { /* This must be an init from scratch, no delimiter yet. */ if (!master_at.dt.ph) return EC_SUCCESS; /* This is bad, will have to wipe out everything. */ return EC_ERROR_INVAL; } if (nc->container_type_copy == NN_OBJ_TRANSACTION_DEL) { if (nc->container_type == NN_OBJ_OLD_COPY) return EC_SUCCESS; /* * The delimiter is there, but it has not been finalized, * which means that there might be objects in the flash which * were not updated after the last delimiter was written. */ return verify_last_section(&master_at.dt, nc); } /* * The delimiter is not there, everything above the last verified * delimiter must go. * * First, create a context for retrieving objects starting at the last * valid delimiter, make sure list index is set properly. */ dpt.mt = master_at.dt; if (dpt.mt.ph == master_at.mt.ph) { dpt.list_index = master_at.list_index; } else { uint8_t i; for (i = 0; i < master_at.list_index; i++) if (list_element_to_ph(i) == dpt.mt.ph) { dpt.list_index = i; break; } } while ((rv = get_next_object(&dpt, nc, 0)) == EC_SUCCESS) delete_object(&dpt, nc); if (rv == EC_ERROR_INVAL) { /* * There must have been an interruption of the saving process, * let's wipe out flash to the end of the current page and * compact the storage. */ size_t remainder_size; const void *p = page_cursor(&master_at.ct); if (dpt.ct.ph != dpt.mt.ph) { /* * The last retrieved object is spanning flash page * boundary. * * If this is not the last object in the flash, this * is an unrecoverable init failure. */ if ((dpt.mt.ph != master_at.mt.ph) || (list_element_to_ph(dpt.list_index - 1) != dpt.ct.ph)) report_no_payload_failure( NVMEMF_CORRUPTED_INIT); /* * Let's erase the page where the last object spilled * into. */ flash_physical_erase((uintptr_t)dpt.mt.ph - CONFIG_PROGRAM_MEMORY_BASE, CONFIG_FLASH_BANK_SIZE); /* * And move it to the available pages part of the * pages list. */ master_at.list_index -= 1; master_at.mt = dpt.ct; } remainder_size = CONFIG_FLASH_BANK_SIZE - dpt.ct.data_offset; memset(nc, 0, remainder_size); write_to_flash(p, nc, remainder_size); /* Make sure compaction starts with the new page. */ start_new_flash_page(0); compact_nvmem(); } else { /* Add delimiter at the very top. */ add_final_delimiter(); } /* Need to re-read the NVMEM cache. */ return EC_ERROR_TRY_AGAIN; } /* * At startup iterate over flash contents and move TPM objects into the * appropriate locations in the NVMEM cache. */ static enum ec_error_list retrieve_nvmem_contents(void) { int rv; int tries; struct max_var_container *vc; struct nn_container *nc; uint8_t res_bitmap[(NV_PSEUDO_RESERVE_LAST + 7) / 8]; /* No saved object will exceed CONFIG_FLASH_BANK_SIZE in size. */ nc = get_scratch_buffer(CONFIG_FLASH_BANK_SIZE); /* * Depending on the state of flash, we might have to do this three * times. */ for (tries = 0; tries < 3; tries++) { memset(&master_at, 0, sizeof(master_at)); memset(nvmem_cache_base(NVMEM_TPM), 0, nvmem_user_sizes[NVMEM_TPM]); memset(res_bitmap, 0, sizeof(res_bitmap)); next_evict_obj_base = 0; while ((rv = get_next_object(&master_at, nc, 0)) == EC_SUCCESS) { switch (nc->container_type) { case NN_OBJ_TUPLE: vc = (struct max_var_container *)nc; total_var_space += vc->t_header.key_len + vc->t_header.val_len; break; /* Keep tuples in flash. */ case NN_OBJ_TPM_RESERVED: restore_reserved(nc + 1, nc->size, res_bitmap); break; case NN_OBJ_TPM_EVICTABLE: restore_object(nc + 1, nc->size); break; default: break; } } rv = verify_delimiter(nc); if (rv != EC_ERROR_TRY_AGAIN) break; } if (rv != EC_SUCCESS) report_no_payload_failure(NVMEMF_UNRECOVERABLE_INIT); rv = verify_reserved(res_bitmap, nc); shared_mem_release(nc); return rv; } enum ec_error_list new_nvmem_init(void) { enum ec_error_list rv; timestamp_t start, init; if (!crypto_enabled()) return EC_ERROR_INVAL; init_in_progress = 1; total_var_space = 0; /* Initialize NVMEM indices. */ NvEarlyStageFindHandle(0); lock_mutex(__LINE__); init_page_list(); start = get_time(); rv = retrieve_nvmem_contents(); init = get_time(); unlock_mutex(__LINE__); init_in_progress = 0; CPRINTS("init took %d", (uint32_t)(init.val - start.val)); return rv; } /* * Browse through the flash storage and save all evictable objects' offsets in * the passed in array. This is used to keep track of objects added or deleted * by the TPM library. */ test_export_static size_t init_object_offsets(uint16_t *offsets, size_t count) { size_t num_objects = 0; uint32_t next_obj_base; uint32_t obj_base; void *obj_addr; obj_base = s_evictNvStart; obj_addr = (uint8_t *)nvmem_cache_base(NVMEM_TPM) + obj_base; memcpy(&next_obj_base, obj_addr, sizeof(next_obj_base)); while (next_obj_base && (next_obj_base <= s_evictNvEnd)) { if (num_objects == count) { /* What do we do here?! */ ccprintf("Too many objects!\n"); break; } offsets[num_objects++] = obj_base - s_evictNvStart + sizeof(next_obj_base); obj_addr = nvmem_cache_base(NVMEM_TPM) + next_obj_base; obj_base = next_obj_base; memcpy(&next_obj_base, obj_addr, sizeof(next_obj_base)); } return num_objects; } static enum ec_error_list update_object(const struct access_tracker *at, struct nn_container *ch, void *cached_object, size_t new_size) { size_t copy_size = new_size; size_t preserved_size; uint32_t preserved_hash; uint8_t *dst = (uint8_t *)(ch + 1); preserved_size = ch->size; preserved_hash = ch->container_hash; /* * Need to copy data into the container, skip reserved type if it is a * reserved object. */ if (ch->container_type == NN_OBJ_TPM_RESERVED) { dst++; copy_size--; } memcpy(dst, cached_object, copy_size); ch->generation++; ch->size = new_size; save_container(ch); ch->generation--; ch->size = preserved_size; ch->container_hash = preserved_hash; return delete_object(at, ch); } static enum ec_error_list update_pcr(const struct access_tracker *at, struct nn_container *ch, uint8_t index, uint8_t *cached) { uint8_t preserved; cached--; preserved = cached[0]; cached[0] = index; update_object(at, ch, cached, ch->size); cached[0] = preserved; return EC_SUCCESS; } static enum ec_error_list save_pcr(struct nn_container *ch, uint8_t reserved_index, const void *pcr, size_t pcr_size) { uint8_t *container_body; ch->container_type = ch->container_type_copy = NN_OBJ_TPM_RESERVED; ch->encrypted = 1; ch->size = pcr_size + 1; ch->generation = 0; container_body = (uint8_t *)(ch + 1); container_body[0] = reserved_index; memcpy(container_body + 1, pcr, pcr_size); return save_container(ch); } static enum ec_error_list maybe_save_pcr(struct nn_container *ch, size_t pcr_index) { const STATE_CLEAR_DATA *scd; const struct pcr_descriptor *pcrd; const void *cached; size_t pcr_size; pcrd = pcr_arrays + pcr_index / NUM_STATIC_PCR; scd = get_scd(); pcr_size = pcrd->pcr_size; cached = (const uint8_t *)&scd->pcrSave + pcrd->pcr_array_offset + pcr_size * (pcr_index % NUM_STATIC_PCR); if (is_empty(cached, pcr_size)) return EC_SUCCESS; return save_pcr(ch, pcr_index + NV_VIRTUAL_RESERVE_LAST, cached, pcr_size); } /* * The process_XXX functions below are used to check and if necessary add, * update or delete objects from the flash based on the NVMEM cache * contents. */ static enum ec_error_list process_pcr(const struct access_tracker *at, struct nn_container *ch, uint8_t index, const uint8_t *saved, uint8_t *pcr_bitmap) { STATE_CLEAR_DATA *scd; const struct pcr_descriptor *pcrd; size_t pcr_bitmap_index; size_t pcr_index; size_t pcr_size; uint8_t *cached; pcr_bitmap_index = index - NV_VIRTUAL_RESERVE_LAST; if (pcr_bitmap_index > NUM_OF_PCRS) return EC_ERROR_INVAL; pcrd = pcr_arrays + pcr_bitmap_index / NUM_STATIC_PCR; pcr_index = pcr_bitmap_index % NUM_STATIC_PCR; pcr_size = pcrd->pcr_size; if (pcr_size != (ch->size - 1)) return EC_ERROR_INVAL; /* This is an error. */ /* Find out base address of the cached PCR. */ scd = get_scd(); cached = (uint8_t *)&scd->pcrSave + pcrd->pcr_array_offset + pcr_size * pcr_index; /* Set bitmap bit to indicate that this PCR was looked at. */ bitmap_bit_set(pcr_bitmap, pcr_bitmap_index); if (memcmp(saved, cached, pcr_size)) return update_pcr(at, ch, index, cached); return EC_SUCCESS; } static enum ec_error_list process_reserved(const struct access_tracker *at, struct nn_container *ch, uint8_t *pcr_bitmap) { NV_RESERVED_ITEM ri; size_t new_size; uint8_t *saved; uint8_t index; void *cached; /* * Find out this object's location in the cache (first byte of the * contents is the index of the reserved object. */ saved = (uint8_t *)(ch + 1); index = *saved++; NvGetReserved(index, &ri); if (ri.size) { void *marshaled; cached = (uint8_t *)nvmem_cache_base(NVMEM_TPM) + ri.offset; /* * For NV_STATE_CLEAR and NV_STATE_RESET cases Let's marshal * cached data to be able to compare it with saved data. */ if (index == NV_STATE_CLEAR) { marshaled = ((uint8_t *)(ch + 1)) + ch->size; new_size = marshal_state_clear(cached, marshaled); cached = marshaled; } else if (index == NV_STATE_RESET) { marshaled = ((uint8_t *)(ch + 1)) + ch->size; new_size = marshal_state_reset_data(cached, marshaled); cached = marshaled; } else { new_size = ri.size; } if ((new_size == (ch->size - 1)) && !memcmp(saved, cached, new_size)) return EC_SUCCESS; return update_object(at, ch, cached, new_size + 1); } /* This must be a PCR. */ return process_pcr(at, ch, index, saved, pcr_bitmap); } static enum ec_error_list process_object(const struct access_tracker *at, struct nn_container *ch, uint16_t *tpm_object_offsets, size_t *num_objects) { size_t i; uint32_t cached_size; uint32_t cached_type; uint32_t flash_type; uint32_t next_obj_base; uint8_t *evict_start; void *pcache; evict_start = (uint8_t *)nvmem_cache_base(NVMEM_TPM) + s_evictNvStart; memcpy(&flash_type, ch + 1, sizeof(flash_type)); for (i = 0; i < *num_objects; i++) { /* Find TPM object in the NVMEM cache. */ pcache = evict_start + tpm_object_offsets[i]; memcpy(&cached_type, pcache, sizeof(cached_type)); if (cached_type == flash_type) break; } if (i == *num_objects) { /* * This object is not in the cache any more, delete it from * flash. */ return delete_object(at, ch); } memcpy(&next_obj_base, (uint8_t *)pcache - sizeof(next_obj_base), sizeof(next_obj_base)); cached_size = next_obj_base - s_evictNvStart - tpm_object_offsets[i]; if ((cached_size != ch->size) || memcmp(ch + 1, pcache, cached_size)) { /* * Object changed. Let's delete the old copy and save the new * one. */ update_object(at, ch, pcache, ch->size); } tpm_object_offsets[i] = tpm_object_offsets[*num_objects - 1]; *num_objects -= 1; return EC_SUCCESS; } static enum ec_error_list save_new_object(uint16_t obj_base, void *buf) { size_t obj_size; struct nn_container *ch = buf; uint32_t next_obj_base; void *obj_addr; obj_addr = (uint8_t *)nvmem_cache_base(NVMEM_TPM) + obj_base + s_evictNvStart; memcpy(&next_obj_base, obj_addr - sizeof(next_obj_base), sizeof(next_obj_base)); obj_size = next_obj_base - obj_base - s_evictNvStart; ch->container_type_copy = ch->container_type = NN_OBJ_TPM_EVICTABLE; ch->encrypted = 1; ch->size = obj_size; ch->generation = 0; memcpy(ch + 1, obj_addr, obj_size); return save_container(ch); } static enum ec_error_list new_nvmem_save_(void) { const void *fence_ph; size_t i; size_t num_objs; struct nn_container *ch; struct access_tracker at = {}; uint16_t fence_offset; /* We don't foresee ever storing this many objects. */ uint16_t tpm_object_offsets[MAX_STORED_EVICTABLE_OBJECTS]; uint8_t pcr_bitmap[(NUM_STATIC_PCR * ARRAY_SIZE(pcr_arrays) + 7) / 8]; /* See if compaction is needed. */ if (master_at.list_index >= (ARRAY_SIZE(page_list) - 3)) { enum ec_error_list rv; rv = compact_nvmem(); if (rv != EC_SUCCESS) return rv; } fence_ph = master_at.mt.ph; fence_offset = master_at.mt.data_offset; num_objs = init_object_offsets(tpm_object_offsets, ARRAY_SIZE(tpm_object_offsets)); memset(pcr_bitmap, 0, sizeof(pcr_bitmap)); del_candidates = get_scratch_buffer(CONFIG_FLASH_BANK_SIZE + sizeof(struct delete_candidates)); ch = (void *)(del_candidates + 1); del_candidates->num_candidates = 0; while ((fence_ph != at.mt.ph) || (fence_offset != at.mt.data_offset)) { int rv; rv = get_next_object(&at, ch, 0); if (rv == EC_ERROR_MEMORY_ALLOCATION) break; if (rv != EC_SUCCESS) { ccprintf("%s: failed to read flash when saving (%d)!\n", __func__, rv); shared_mem_release(ch); return rv; } if (ch->container_type == NN_OBJ_TPM_RESERVED) { process_reserved(&at, ch, pcr_bitmap); continue; } if (ch->container_type == NN_OBJ_TPM_EVICTABLE) { process_object(&at, ch, tpm_object_offsets, &num_objs); continue; } } /* Now save new objects, if any. */ for (i = 0; i < num_objs; i++) save_new_object(tpm_object_offsets[i], ch); /* And new pcrs, if any. */ for (i = 0; i < NUM_OF_PCRS; i++) { if (bitmap_bit_check(pcr_bitmap, i)) continue; maybe_save_pcr(ch, i); } #if defined(NVMEM_TEST_BUILD) if (failure_mode == TEST_FAIL_WHEN_SAVING) { shared_mem_release(del_candidates); del_candidates = NULL; return EC_SUCCESS; } #endif /* * Add a delimiter if there have been new containers added to the * flash. */ if (del_candidates->num_candidates || (fence_offset != master_at.mt.data_offset) || (fence_ph != master_at.mt.ph)) { const void *del = page_cursor(&master_at.mt); add_delimiter(); if (del_candidates->num_candidates) { /* Now delete objects which need to be deleted. */ for (i = 0; i < del_candidates->num_candidates; i++) invalidate_object( del_candidates->candidates[i]); } #if defined(NVMEM_TEST_BUILD) if (failure_mode == TEST_FAIL_WHEN_INVALIDATING) { shared_mem_release(del_candidates); del_candidates = NULL; return EC_SUCCESS; } #endif finalize_delimiter(del); } shared_mem_release(del_candidates); del_candidates = NULL; return EC_SUCCESS; } enum ec_error_list new_nvmem_save(void) { enum ec_error_list rv; if (!crypto_enabled()) return EC_ERROR_INVAL; lock_mutex(__LINE__); rv = new_nvmem_save_(); unlock_mutex(__LINE__); return rv; } /* Caller must free memory allocated by this function! */ static struct max_var_container *find_var(const uint8_t *key, size_t key_len, struct access_tracker *at) { int rv; struct max_var_container *vc; vc = get_scratch_buffer(CONFIG_FLASH_BANK_SIZE); /* * Let's iterate over all objects there are and look for matching * tuples. */ while ((rv = get_next_object(at, &vc->c_header, 0)) == EC_SUCCESS) { if (vc->c_header.container_type != NN_OBJ_TUPLE) continue; /* Verify consistency, first that the sizes match */ if ((vc->t_header.key_len + vc->t_header.val_len + sizeof(vc->t_header)) != vc->c_header.size) { ccprintf("%s: - inconsistent sizes!\n", __func__); /* report error here. */ continue; } /* Ok, found a tuple, does the key match? */ if ((key_len == vc->t_header.key_len) && !memcmp(key, vc->body, key_len)) /* Yes, it does! */ return vc; } shared_mem_release(vc); return NULL; } const struct tuple *getvar(const uint8_t *key, uint8_t key_len) { const struct max_var_container *vc; struct access_tracker at = {}; if (!crypto_enabled()) return NULL; if (!key || !key_len) return NULL; lock_mutex(__LINE__); vc = find_var(key, key_len, &at); unlock_mutex(__LINE__); if (vc) return &vc->t_header; return NULL; } void freevar(const struct tuple *var) { void *vc; if (!var) return; vc = (uint8_t *)var - offsetof(struct max_var_container, t_header); shared_mem_release(vc); } static enum ec_error_list save_container(struct nn_container *nc) { uint32_t hash; uint32_t salt[4]; nc->container_hash = 0; app_compute_hash_wrapper(nc, sizeof(*nc) + nc->size, &hash, sizeof(hash)); nc->container_hash = hash; /* This will truncate it. */ /* Skip transactions delimiters. */ if (nc->size) { salt[0] = master_at.mt.ph->page_number; salt[1] = master_at.mt.data_offset; salt[2] = nc->container_hash; salt[3] = 0; if (!app_cipher(salt, nc + 1, nc + 1, nc->size)) report_no_payload_failure(NVMEMF_CIPHER_ERROR); } return save_object(nc); } static int setvar_(const uint8_t *key, uint8_t key_len, const uint8_t *val, uint8_t val_len) { enum ec_error_list rv; int erase_request; size_t new_var_space; size_t old_var_space; struct max_var_container *vc; struct access_tracker at = {}; const struct nn_container *del; if (!key || !key_len) return EC_ERROR_INVAL; new_var_space = key_len + val_len; if (new_var_space > MAX_VAR_BODY_SPACE) /* Too much space would be needed. */ return EC_ERROR_INVAL; erase_request = !val || !val_len; /* See if compaction is needed. */ if (!erase_request && (master_at.list_index >= (ARRAY_SIZE(page_list) - 3))) { rv = compact_nvmem(); if (rv != EC_SUCCESS) return rv; } vc = find_var(key, key_len, &at); if (erase_request) { if (!vc) /* Nothing to erase. */ return EC_SUCCESS; rv = invalidate_object( (struct nn_container *)((uintptr_t)at.ct.ph + at.ct.data_offset)); if (rv == EC_SUCCESS) total_var_space -= vc->t_header.key_len + vc->t_header.val_len; shared_mem_release(vc); return rv; } /* Is this variable already there? */ if (!vc) { /* No, it is not. Will it fit? */ if ((new_var_space + total_var_space) > MAX_VAR_TOTAL_SPACE) /* No, it will not. */ return EC_ERROR_OVERFLOW; rv = save_var(key, key_len, val, val_len, vc); if (rv == EC_SUCCESS) add_final_delimiter(); return rv; } /* The variable was found, let's see if the value is being changed. */ if (vc->t_header.val_len == val_len && !memcmp(val, vc->body + key_len, val_len)) { shared_mem_release(vc); return EC_SUCCESS; } /* Ok, the variable was found, and is of a different value. */ old_var_space = vc->t_header.val_len + vc->t_header.key_len; if ((old_var_space < new_var_space) && ((total_var_space + new_var_space - old_var_space) > MAX_VAR_TOTAL_SPACE)) { shared_mem_release(vc); return EC_ERROR_OVERFLOW; } /* Save the new instance first with the larger generation number. */ vc->c_header.generation++; rv = save_var(key, key_len, val, val_len, vc); shared_mem_release(vc); del = page_cursor(&master_at.mt); #if defined(NVMEM_TEST_BUILD) if (failure_mode == TEST_FAIL_SAVING_VAR) return EC_SUCCESS; #endif add_delimiter(); if (rv == EC_SUCCESS) { rv = invalidate_object( (struct nn_container *)((uintptr_t)at.ct.ph + at.ct.data_offset)); if (rv == EC_SUCCESS) { total_var_space -= old_var_space; #if defined(NVMEM_TEST_BUILD) if (failure_mode != TEST_FAIL_FINALIZING_VAR) #endif finalize_delimiter(del); } } return rv; } int setvar(const uint8_t *key, uint8_t key_len, const uint8_t *val, uint8_t val_len) { int rv; if (!crypto_enabled()) return EC_ERROR_INVAL; lock_mutex(__LINE__); rv = setvar_(key, key_len, val, val_len); unlock_mutex(__LINE__); return rv; } static void dump_contents(const struct nn_container *ch) { const uint8_t *buf = (const void *)ch; size_t i; size_t total_size = sizeof(*ch) + ch->size; for (i = 0; i < total_size; i++) { if (!(i % 16)) { ccprintf("\n"); cflush(); } ccprintf(" %02x", buf[i]); } ccprintf("\n"); } /* * Clear tpm data from nvmem. First fill up the current top page with erased * objects, then compact the flash storage, removing all TPM related objects. * This would guarantee that all pages where TPM objecs were stored would be * erased. */ int nvmem_erase_tpm_data(void) { const uint8_t *key; const uint8_t *val; int rv; struct nn_container *ch; struct access_tracker at = {}; uint8_t saved_list_index; uint8_t key_len; if (!crypto_enabled()) return EC_ERROR_INVAL; ch = get_scratch_buffer(CONFIG_FLASH_BANK_SIZE); lock_mutex(__LINE__); while (get_next_object(&at, ch, 0) == EC_SUCCESS) { if ((ch->container_type != NN_OBJ_TPM_RESERVED) && (ch->container_type != NN_OBJ_TPM_EVICTABLE)) continue; delete_object(&at, ch); } unlock_mutex(__LINE__); shared_mem_release(ch); /* * Now fill up the current flash page with erased objects to make sure * that it would be erased during next compaction. Use dummy key, * value pairs as the erase objects. */ saved_list_index = master_at.list_index; key = (const uint8_t *)nvmem_erase_tpm_data; val = (const uint8_t *)nvmem_erase_tpm_data; key_len = MAX_VAR_BODY_SPACE - 255; do { size_t to_go_in_page; uint8_t val_len; to_go_in_page = CONFIG_FLASH_BANK_SIZE - master_at.mt.data_offset; if (to_go_in_page > (MAX_VAR_BODY_SPACE + offsetof(struct max_var_container, body) - 1)) { val_len = MAX_VAR_BODY_SPACE - key_len; } else { /* * Let's not write more than we have to get over the * page limit. The minimum size we need is: * * + + 2 * * (where key and value are of one byte each). */ if (to_go_in_page < (offsetof(struct max_var_container, body) + 2)) { /* * There is very little room left, even key * and value of size of one each is enough to * go over. */ key_len = 1; val_len = 1; } else { size_t need_to_cover; /* How much space key and value should cover? */ need_to_cover = to_go_in_page - offsetof(struct max_var_container, body) + 1; key_len = need_to_cover / 2; val_len = need_to_cover - key_len; } } if (setvar(key, key_len, val, val_len) != EC_SUCCESS) ccprintf("%s: adding var failed!\n", __func__); if (setvar(key, key_len, NULL, 0) != EC_SUCCESS) ccprintf("%s: deleting var failed!\n", __func__); } while (master_at.list_index != (saved_list_index + 1)); lock_mutex(__LINE__); rv = compact_nvmem(); unlock_mutex(__LINE__); if (rv == EC_SUCCESS) rv = new_nvmem_init(); return rv; } /* * Function which verifes flash contents integrity (and printing objects it * finds, if requested by the caller). All objects' active and deleted alike * integrity is verified by get_next_object(). */ test_export_static enum ec_error_list browse_flash_contents(int print) { int active = 0; int count = 0; int rv = EC_SUCCESS; size_t line_len = 0; struct nn_container *ch; struct access_tracker at = {}; if (!crypto_enabled()) { ccprintf("Crypto services not available\n"); return EC_ERROR_INVAL; } ch = get_scratch_buffer(CONFIG_FLASH_BANK_SIZE); lock_mutex(__LINE__); while ((rv = get_next_object(&at, ch, 1)) == EC_SUCCESS) { uint8_t ctype = ch->container_type; count++; if ((ctype != NN_OBJ_OLD_COPY) && (ctype != NN_OBJ_TRANSACTION_DEL)) active++; if (print) { char erased; if (ctype == NN_OBJ_OLD_COPY) erased = 'x'; else erased = ' '; if (ch->container_type_copy == NN_OBJ_TPM_RESERVED) { ccprintf("%cR:%02x.%d ", erased, *((uint8_t *)(ch + 1)), ch->generation); } else { uint32_t index; char tag; switch (ch->container_type_copy) { case NN_OBJ_TPM_EVICTABLE: tag = 'E'; break; case NN_OBJ_TUPLE: tag = 'T'; break; case NN_OBJ_TRANSACTION_DEL: tag = 's'; /* 's' for separator. */ break; default: tag = '?'; break; } if (ch->container_type_copy != NN_OBJ_TRANSACTION_DEL) memcpy(&index, ch + 1, sizeof(index)); else index = 0; ccprintf("%c%c:%08x.%d ", erased, tag, index, ch->generation); } if (print > 1) { dump_contents(ch); continue; } if (line_len > 70) { ccprintf("\n"); cflush(); line_len = 0; } else { line_len += 11; } } } unlock_mutex(__LINE__); shared_mem_release(ch); if (rv == EC_ERROR_MEMORY_ALLOCATION) { ccprintf("%schecked %d objects, %d active\n", print ? "\n" : "", count, active); rv = EC_SUCCESS; } return rv; } static int command_dump_nvmem(int argc, char **argv) { int print = 1; nvmem_disable_commits(); #ifdef CR50_DEV /* Allow dumping ecnrypted NVMEM contents only to DEV builds. */ print += (argc > 1); #endif browse_flash_contents(print); nvmem_enable_commits(); return 0; } DECLARE_SAFE_CONSOLE_COMMAND(dump_nvmem, command_dump_nvmem, "", "");