diff options
-rw-r--r-- | drivers/char/tpm/eventlog/efi.c | 59 | ||||
-rw-r--r-- | drivers/char/tpm/eventlog/tpm2.c | 47 | ||||
-rw-r--r-- | drivers/char/tpm/tpm-chip.c | 6 | ||||
-rw-r--r-- | drivers/char/tpm/tpm1-cmd.c | 7 | ||||
-rw-r--r-- | drivers/char/tpm/tpm2-cmd.c | 7 | ||||
-rw-r--r-- | drivers/firmware/efi/efi.c | 2 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 15 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/efistub.h | 2 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/fdt.c | 27 | ||||
-rw-r--r-- | drivers/firmware/efi/libstub/tpm.c | 80 | ||||
-rw-r--r-- | drivers/firmware/efi/tpm.c | 63 | ||||
-rw-r--r-- | include/linux/efi.h | 10 | ||||
-rw-r--r-- | include/linux/tpm_eventlog.h | 152 |
13 files changed, 378 insertions, 99 deletions
diff --git a/drivers/char/tpm/eventlog/efi.c b/drivers/char/tpm/eventlog/efi.c index 3e44362e469c..6bb023de17f1 100644 --- a/drivers/char/tpm/eventlog/efi.c +++ b/drivers/char/tpm/eventlog/efi.c @@ -16,10 +16,13 @@ int tpm_read_log_efi(struct tpm_chip *chip) { + struct efi_tcg2_final_events_table *final_tbl = NULL; struct linux_efi_tpm_eventlog *log_tbl; struct tpm_bios_log *log; u32 log_size; u8 tpm_log_version; + void *tmp; + int ret; if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) return -ENODEV; @@ -47,15 +50,57 @@ int tpm_read_log_efi(struct tpm_chip *chip) /* malloc EventLog space */ log->bios_event_log = kmemdup(log_tbl->log, log_size, GFP_KERNEL); - if (!log->bios_event_log) - goto err_memunmap; - log->bios_event_log_end = log->bios_event_log + log_size; + if (!log->bios_event_log) { + ret = -ENOMEM; + goto out; + } + log->bios_event_log_end = log->bios_event_log + log_size; tpm_log_version = log_tbl->version; - memunmap(log_tbl); - return tpm_log_version; -err_memunmap: + ret = tpm_log_version; + + if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR || + efi_tpm_final_log_size == 0 || + tpm_log_version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) + goto out; + + final_tbl = memremap(efi.tpm_final_log, + sizeof(*final_tbl) + efi_tpm_final_log_size, + MEMREMAP_WB); + if (!final_tbl) { + pr_err("Could not map UEFI TPM final log\n"); + kfree(log->bios_event_log); + ret = -ENOMEM; + goto out; + } + + efi_tpm_final_log_size -= log_tbl->final_events_preboot_size; + + tmp = krealloc(log->bios_event_log, + log_size + efi_tpm_final_log_size, + GFP_KERNEL); + if (!tmp) { + kfree(log->bios_event_log); + ret = -ENOMEM; + goto out; + } + + log->bios_event_log = tmp; + + /* + * Copy any of the final events log that didn't also end up in the + * main log. Events can be logged in both if events are generated + * between GetEventLog() and ExitBootServices(). + */ + memcpy((void *)log->bios_event_log + log_size, + final_tbl->events + log_tbl->final_events_preboot_size, + efi_tpm_final_log_size); + log->bios_event_log_end = log->bios_event_log + + log_size + efi_tpm_final_log_size; + +out: + memunmap(final_tbl); memunmap(log_tbl); - return -ENOMEM; + return ret; } diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c index d506362e046f..b9aeda1cbcd7 100644 --- a/drivers/char/tpm/eventlog/tpm2.c +++ b/drivers/char/tpm/eventlog/tpm2.c @@ -36,52 +36,7 @@ static size_t calc_tpm2_event_size(struct tcg_pcr_event2_head *event, struct tcg_pcr_event *event_header) { - struct tcg_efi_specid_event_head *efispecid; - struct tcg_event_field *event_field; - void *marker; - void *marker_start; - u32 halg_size; - size_t size; - u16 halg; - int i; - int j; - - marker = event; - marker_start = marker; - marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type) - + sizeof(event->count); - - efispecid = (struct tcg_efi_specid_event_head *)event_header->event; - - /* Check if event is malformed. */ - if (event->count > efispecid->num_algs) - return 0; - - for (i = 0; i < event->count; i++) { - halg_size = sizeof(event->digests[i].alg_id); - memcpy(&halg, marker, halg_size); - marker = marker + halg_size; - for (j = 0; j < efispecid->num_algs; j++) { - if (halg == efispecid->digest_sizes[j].alg_id) { - marker += - efispecid->digest_sizes[j].digest_size; - break; - } - } - /* Algorithm without known length. Such event is unparseable. */ - if (j == efispecid->num_algs) - return 0; - } - - event_field = (struct tcg_event_field *)marker; - marker = marker + sizeof(event_field->event_size) - + event_field->event_size; - size = marker - marker_start; - - if ((event->event_type == 0) && (event_field->event_size == 0)) - return 0; - - return size; + return __calc_tpm2_event_size(event, event_header, false); } static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 90325e1749fb..d47ad10a35fe 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -289,15 +289,15 @@ static int tpm_class_shutdown(struct device *dev) { struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); + down_write(&chip->ops_sem); if (chip->flags & TPM_CHIP_FLAG_TPM2) { - down_write(&chip->ops_sem); if (!tpm_chip_start(chip)) { tpm2_shutdown(chip, TPM2_SU_CLEAR); tpm_chip_stop(chip); } - chip->ops = NULL; - up_write(&chip->ops_sem); } + chip->ops = NULL; + up_write(&chip->ops_sem); return 0; } diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index 85dcf2654d11..faacbe1ffa1a 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -510,7 +510,7 @@ struct tpm1_get_random_out { * * Return: * * number of bytes read - * * -errno or a TPM return code otherwise + * * -errno (positive TPM return codes are masked to -EIO) */ int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max) { @@ -531,8 +531,11 @@ int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max) rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len), "attempting get random"); - if (rc) + if (rc) { + if (rc > 0) + rc = -EIO; goto out; + } out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE]; diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 4de49924cfc4..d103545e4055 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -297,7 +297,7 @@ struct tpm2_get_random_out { * * Return: * size of the buffer on success, - * -errno otherwise + * -errno otherwise (positive TPM return codes are masked to -EIO) */ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) { @@ -324,8 +324,11 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) offsetof(struct tpm2_get_random_out, buffer), "attempting get random"); - if (err) + if (err) { + if (err > 0) + err = -EIO; goto out; + } out = (struct tpm2_get_random_out *) &buf.data[TPM_HEADER_SIZE]; diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 4b7cf7bc0ded..ad3b1f4866b3 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -52,6 +52,7 @@ struct efi __read_mostly efi = { .mem_attr_table = EFI_INVALID_TABLE_ADDR, .rng_seed = EFI_INVALID_TABLE_ADDR, .tpm_log = EFI_INVALID_TABLE_ADDR, + .tpm_final_log = EFI_INVALID_TABLE_ADDR, .mem_reserve = EFI_INVALID_TABLE_ADDR, }; EXPORT_SYMBOL(efi); @@ -484,6 +485,7 @@ static __initdata efi_config_table_type_t common_tables[] = { {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table}, {LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed}, {LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log}, + {LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log}, {LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve}, {NULL_GUID, NULL, NULL}, }; diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index e4610e72b78f..1db780c0f07b 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -926,3 +926,18 @@ free_map: fail: return status; } + +void *get_efi_config_table(efi_system_table_t *sys_table, efi_guid_t guid) +{ + efi_config_table_t *tables = (efi_config_table_t *)sys_table->tables; + int i; + + for (i = 0; i < sys_table->nr_tables; i++) { + if (efi_guidcmp(tables[i].guid, guid) != 0) + continue; + + return (void *)tables[i].table; + } + + return NULL; +} diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 1b1dfcaa6fb9..7f1556fd867d 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -65,6 +65,8 @@ efi_status_t check_platform_features(efi_system_table_t *sys_table_arg); efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg); +void *get_efi_config_table(efi_system_table_t *sys_table, efi_guid_t guid); + /* Helper macros for the usual case of using simple C variables: */ #ifndef fdt_setprop_inplace_var #define fdt_setprop_inplace_var(fdt, node_offset, name, var) \ diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 5440ba17a1c5..0bf0190917e0 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -363,26 +363,17 @@ fail: void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size) { - efi_guid_t fdt_guid = DEVICE_TREE_GUID; - efi_config_table_t *tables; - int i; + void *fdt; - tables = (efi_config_table_t *)sys_table->tables; + fdt = get_efi_config_table(sys_table, DEVICE_TREE_GUID); - for (i = 0; i < sys_table->nr_tables; i++) { - void *fdt; + if (!fdt) + return NULL; - if (efi_guidcmp(tables[i].guid, fdt_guid) != 0) - continue; - - fdt = (void *)tables[i].table; - if (fdt_check_header(fdt) != 0) { - pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); - return NULL; - } - *fdt_size = fdt_totalsize(fdt); - return fdt; + if (fdt_check_header(fdt) != 0) { + pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); + return NULL; } - - return NULL; + *fdt_size = fdt_totalsize(fdt); + return fdt; } diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c index 5bd04f75d8d6..eb9af83e4d59 100644 --- a/drivers/firmware/efi/libstub/tpm.c +++ b/drivers/firmware/efi/libstub/tpm.c @@ -57,31 +57,40 @@ void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) #endif -static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) +void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) { efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; efi_status_t status; efi_physical_addr_t log_location = 0, log_last_entry = 0; struct linux_efi_tpm_eventlog *log_tbl = NULL; + struct efi_tcg2_final_events_table *final_events_table; unsigned long first_entry_addr, last_entry_addr; size_t log_size, last_entry_size; efi_bool_t truncated; + int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2; void *tcg2_protocol = NULL; + int final_events_size = 0; status = efi_call_early(locate_protocol, &tcg2_guid, NULL, &tcg2_protocol); if (status != EFI_SUCCESS) return; - status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol, - EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2, - &log_location, &log_last_entry, &truncated); - if (status != EFI_SUCCESS) - return; + status = efi_call_proto(efi_tcg2_protocol, get_event_log, + tcg2_protocol, version, &log_location, + &log_last_entry, &truncated); + + if (status != EFI_SUCCESS || !log_location) { + version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + status = efi_call_proto(efi_tcg2_protocol, get_event_log, + tcg2_protocol, version, &log_location, + &log_last_entry, &truncated); + if (status != EFI_SUCCESS || !log_location) + return; + + } - if (!log_location) - return; first_entry_addr = (unsigned long) log_location; /* @@ -96,8 +105,23 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) * We need to calculate its size to deduce the full size of * the logs. */ - last_entry_size = sizeof(struct tcpa_event) + - ((struct tcpa_event *) last_entry_addr)->event_size; + if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) { + /* + * The TCG2 log format has variable length entries, + * and the information to decode the hash algorithms + * back into a size is contained in the first entry - + * pass a pointer to the final entry (to calculate its + * size) and the first entry (so we know how long each + * digest is) + */ + last_entry_size = + __calc_tpm2_event_size((void *)last_entry_addr, + (void *)(long)log_location, + false); + } else { + last_entry_size = sizeof(struct tcpa_event) + + ((struct tcpa_event *) last_entry_addr)->event_size; + } log_size = log_last_entry - log_location + last_entry_size; } @@ -112,9 +136,37 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) return; } + /* + * Figure out whether any events have already been logged to the + * final events structure, and if so how much space they take up + */ + final_events_table = get_efi_config_table(sys_table_arg, + LINUX_EFI_TPM_FINAL_LOG_GUID); + if (final_events_table && final_events_table->nr_events) { + struct tcg_pcr_event2_head *header; + int offset; + void *data; + int event_size; + int i = final_events_table->nr_events; + + data = (void *)final_events_table; + offset = sizeof(final_events_table->version) + + sizeof(final_events_table->nr_events); + + while (i > 0) { + header = data + offset + final_events_size; + event_size = __calc_tpm2_event_size(header, + (void *)(long)log_location, + false); + final_events_size += event_size; + i--; + } + } + memset(log_tbl, 0, sizeof(*log_tbl) + log_size); log_tbl->size = log_size; - log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + log_tbl->final_events_preboot_size = final_events_size; + log_tbl->version = version; memcpy(log_tbl->log, (void *) first_entry_addr, log_size); status = efi_call_early(install_configuration_table, @@ -126,9 +178,3 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) err_free: efi_call_early(free_pool, log_tbl); } - -void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) -{ - /* Only try to retrieve the logs in 1.2 format. */ - efi_retrieve_tpm2_eventlog_1_2(sys_table_arg); -} diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c index 3a689b40ccc0..1d3f5ca3eaaf 100644 --- a/drivers/firmware/efi/tpm.c +++ b/drivers/firmware/efi/tpm.c @@ -4,11 +4,34 @@ * Thiebaud Weksteen <tweek@google.com> */ +#define TPM_MEMREMAP(start, size) early_memremap(start, size) +#define TPM_MEMUNMAP(start, size) early_memunmap(start, size) + +#include <asm/early_ioremap.h> #include <linux/efi.h> #include <linux/init.h> #include <linux/memblock.h> +#include <linux/tpm_eventlog.h> -#include <asm/early_ioremap.h> +int efi_tpm_final_log_size; +EXPORT_SYMBOL(efi_tpm_final_log_size); + +static int tpm2_calc_event_log_size(void *data, int count, void *size_info) +{ + struct tcg_pcr_event2_head *header; + int event_size, size = 0; + + while (count > 0) { + header = data + size; + event_size = __calc_tpm2_event_size(header, size_info, true); + if (event_size == 0) + return -1; + size += event_size; + count--; + } + + return size; +} /* * Reserve the memory associated with the TPM Event Log configuration table. @@ -16,22 +39,54 @@ int __init efi_tpm_eventlog_init(void) { struct linux_efi_tpm_eventlog *log_tbl; + struct efi_tcg2_final_events_table *final_tbl; unsigned int tbl_size; + int ret = 0; - if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) + if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) { + /* + * We can't calculate the size of the final events without the + * first entry in the TPM log, so bail here. + */ return 0; + } log_tbl = early_memremap(efi.tpm_log, sizeof(*log_tbl)); if (!log_tbl) { pr_err("Failed to map TPM Event Log table @ 0x%lx\n", - efi.tpm_log); + efi.tpm_log); efi.tpm_log = EFI_INVALID_TABLE_ADDR; return -ENOMEM; } tbl_size = sizeof(*log_tbl) + log_tbl->size; memblock_reserve(efi.tpm_log, tbl_size); + + if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) + goto out; + + final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl)); + + if (!final_tbl) { + pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n", + efi.tpm_final_log); + efi.tpm_final_log = EFI_INVALID_TABLE_ADDR; + ret = -ENOMEM; + goto out; + } + + tbl_size = tpm2_calc_event_log_size((void *)efi.tpm_final_log + + sizeof(final_tbl->version) + + sizeof(final_tbl->nr_events), + final_tbl->nr_events, + log_tbl->log); + memblock_reserve((unsigned long)final_tbl, + tbl_size + sizeof(*final_tbl)); + early_memunmap(final_tbl, sizeof(*final_tbl)); + efi_tpm_final_log_size = tbl_size; + +out: early_memunmap(log_tbl, sizeof(*log_tbl)); - return 0; + return ret; } diff --git a/include/linux/efi.h b/include/linux/efi.h index 6ebc2098cfe1..f87fabea4a85 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -689,6 +689,7 @@ void efi_native_runtime_setup(void); #define LINUX_EFI_LOADER_ENTRY_GUID EFI_GUID(0x4a67b082, 0x0a4c, 0x41cf, 0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f) #define LINUX_EFI_RANDOM_SEED_TABLE_GUID EFI_GUID(0x1ce1e5bc, 0x7ceb, 0x42f2, 0x81, 0xe5, 0x8a, 0xad, 0xf1, 0x80, 0xf5, 0x7b) #define LINUX_EFI_TPM_EVENT_LOG_GUID EFI_GUID(0xb7799cb0, 0xeca2, 0x4943, 0x96, 0x67, 0x1f, 0xae, 0x07, 0xb7, 0x47, 0xfa) +#define LINUX_EFI_TPM_FINAL_LOG_GUID EFI_GUID(0x1e2ed096, 0x30e2, 0x4254, 0xbd, 0x89, 0x86, 0x3b, 0xbe, 0xf8, 0x23, 0x25) #define LINUX_EFI_MEMRESERVE_TABLE_GUID EFI_GUID(0x888eb0c6, 0x8ede, 0x4ff5, 0xa8, 0xf0, 0x9a, 0xee, 0x5c, 0xb9, 0x77, 0xc2) typedef struct { @@ -996,6 +997,7 @@ extern struct efi { unsigned long mem_attr_table; /* memory attributes table */ unsigned long rng_seed; /* UEFI firmware random seed */ unsigned long tpm_log; /* TPM2 Event Log table */ + unsigned long tpm_final_log; /* TPM2 Final Events Log table */ unsigned long mem_reserve; /* Linux EFI memreserve table */ efi_get_time_t *get_time; efi_set_time_t *set_time; @@ -1706,12 +1708,20 @@ struct linux_efi_random_seed { struct linux_efi_tpm_eventlog { u32 size; + u32 final_events_preboot_size; u8 version; u8 log[]; }; extern int efi_tpm_eventlog_init(void); +struct efi_tcg2_final_events_table { + u64 version; + u64 nr_events; + u8 events[]; +}; +extern int efi_tpm_final_log_size; + /* * efi_runtime_service() function identifiers. * "NONE" is used by efi_recover_from_page_fault() to check if the page diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h index 81519f163211..63238c84dc0b 100644 --- a/include/linux/tpm_eventlog.h +++ b/include/linux/tpm_eventlog.h @@ -112,4 +112,156 @@ struct tcg_pcr_event2_head { struct tpm_digest digests[]; } __packed; +struct tcg_algorithm_size { + u16 algorithm_id; + u16 algorithm_size; +}; + +struct tcg_algorithm_info { + u8 signature[16]; + u32 platform_class; + u8 spec_version_minor; + u8 spec_version_major; + u8 spec_errata; + u8 uintn_size; + u32 number_of_algorithms; + struct tcg_algorithm_size digest_sizes[]; +}; + +#ifndef TPM_MEMREMAP +#define TPM_MEMREMAP(start, size) NULL +#endif + +#ifndef TPM_MEMUNMAP +#define TPM_MEMUNMAP(start, size) do{} while(0) +#endif + +/** + * __calc_tpm2_event_size - calculate the size of a TPM2 event log entry + * @event: Pointer to the event whose size should be calculated + * @event_header: Pointer to the initial event containing the digest lengths + * @do_mapping: Whether or not the event needs to be mapped + * + * The TPM2 event log format can contain multiple digests corresponding to + * separate PCR banks, and also contains a variable length of the data that + * was measured. This requires knowledge of how long each digest type is, + * and this information is contained within the first event in the log. + * + * We calculate the length by examining the number of events, and then looking + * at each event in turn to determine how much space is used for events in + * total. Once we've done this we know the offset of the data length field, + * and can calculate the total size of the event. + * + * Return: size of the event on success, <0 on failure + */ + +static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event, + struct tcg_pcr_event *event_header, + bool do_mapping) +{ + struct tcg_efi_specid_event_head *efispecid; + struct tcg_event_field *event_field; + void *mapping = NULL; + int mapping_size; + void *marker; + void *marker_start; + u32 halg_size; + size_t size; + u16 halg; + int i; + int j; + + marker = event; + marker_start = marker; + marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type) + + sizeof(event->count); + + /* Map the event header */ + if (do_mapping) { + mapping_size = marker - marker_start; + mapping = TPM_MEMREMAP((unsigned long)marker_start, + mapping_size); + if (!mapping) { + size = 0; + goto out; + } + } else { + mapping = marker_start; + } + + event = (struct tcg_pcr_event2_head *)mapping; + + efispecid = (struct tcg_efi_specid_event_head *)event_header->event; + + /* Check if event is malformed. */ + if (event->count > efispecid->num_algs) { + size = 0; + goto out; + } + + for (i = 0; i < event->count; i++) { + halg_size = sizeof(event->digests[i].alg_id); + + /* Map the digest's algorithm identifier */ + if (do_mapping) { + TPM_MEMUNMAP(mapping, mapping_size); + mapping_size = halg_size; + mapping = TPM_MEMREMAP((unsigned long)marker, + mapping_size); + if (!mapping) { + size = 0; + goto out; + } + } else { + mapping = marker; + } + + memcpy(&halg, mapping, halg_size); + marker = marker + halg_size; + + for (j = 0; j < efispecid->num_algs; j++) { + if (halg == efispecid->digest_sizes[j].alg_id) { + marker += + efispecid->digest_sizes[j].digest_size; + break; + } + } + /* Algorithm without known length. Such event is unparseable. */ + if (j == efispecid->num_algs) { + size = 0; + goto out; + } + } + + /* + * Map the event size - we don't read from the event itself, so + * we don't need to map it + */ + if (do_mapping) { + TPM_MEMUNMAP(mapping, mapping_size); + mapping_size += sizeof(event_field->event_size); + mapping = TPM_MEMREMAP((unsigned long)marker, + mapping_size); + if (!mapping) { + size = 0; + goto out; + } + } else { + mapping = marker; + } + + event_field = (struct tcg_event_field *)mapping; + + marker = marker + sizeof(event_field->event_size) + + event_field->event_size; + size = marker - marker_start; + + if ((event->event_type == 0) && (event_field->event_size == 0)) + size = 0; +out: + if (do_mapping) + TPM_MEMUNMAP(mapping, mapping_size); + return size; +} + #endif |