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|
/* 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 <stdint.h>
#include <string.h>
#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"
/*
* ==== 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;
/*
* 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);
/* 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)
{
flash_log_add_event(
FE_LOG_NVMEM,
payload_union_size +
offsetof(struct nvmem_failure_payload, size),
payload);
ccprintf("Logging failure %d\n", payload->failure_type);
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 = NVMEMF_INCONSISTENT_FLASH_CONTENTS;
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)
ccprintf("%s: waited %d cycles!\n", __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);
}
/*
* 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 - 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)) {
ccprintf("%s: container hash mismatch!\n", __func__);
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();
ccprintf("Compaction done, went from %d to %d bytes\n", 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 (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", __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", __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);
ccprintf("Migration success, used %d bytes of flash\n",
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) {
ccprintf("%s: corrupted page at %p!\n", __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) {
ccprintf("Init nvmem from scratch\n");
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;
}
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);
remainder_size =
CONFIG_FLASH_BANK_SIZE - master_at.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 twice. */
for (tries = 0; tries < 2; 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) {
/*
* Something is really messed up, need to wipe out and start
* from scratch?
*/
ccprintf("%s:%d FAILURE!\n", __func__, __LINE__);
}
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;
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__);
ccprintf("init took %d\n", (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_BODY_SPACE))
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:
*
* <container header size> + <tuple header size> + 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)
{
nvmem_disable_commits();
browse_flash_contents(1 + (argc > 1));
nvmem_enable_commits();
return 0;
}
DECLARE_SAFE_CONSOLE_COMMAND(dump_nvmem, command_dump_nvmem, "", "");
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