[PATCH v3 2/3] efi_loader: add UEFI GPT measurement
Heinrich Schuchardt
xypron.glpk at gmx.de
Fri Oct 1 18:28:42 CEST 2021
On 10/1/21 13:18, Masahisa Kojima wrote:
> This commit adds the UEFI GPT disk partition topology
> measurement required in TCG PC Client PFP Spec.
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
>
> Changes in v3:
> - EV_EFI_GPT_EVENT is measured before EV_SEPARATOR, same as
> other PCRs
> - use PTR_ARRAY instead of ARRAY
> - create sub-function of allocating io_aligned buffer
> - move search_gpt_dp_node() into efi_device_path.c
>
> include/blk.h | 3 +
> include/efi_loader.h | 3 +-
> include/efi_tcg2.h | 12 +++
> lib/efi_loader/efi_boottime.c | 2 +-
> lib/efi_loader/efi_device_path.c | 27 +++++
> lib/efi_loader/efi_tcg2.c | 163 ++++++++++++++++++++++++++++++-
> 6 files changed, 207 insertions(+), 3 deletions(-)
>
> diff --git a/include/blk.h b/include/blk.h
> index 19bab081c2..f0cc7ca1a2 100644
> --- a/include/blk.h
> +++ b/include/blk.h
> @@ -45,6 +45,9 @@ enum if_type {
> #define BLK_PRD_SIZE 20
> #define BLK_REV_SIZE 8
>
> +#define PART_FORMAT_PCAT 0x1
> +#define PART_FORMAT_GPT 0x2
> +
> /*
> * Identifies the partition table type (ie. MBR vs GPT GUID) signature
> */
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 13f0c24058..c557e8bee6 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -503,7 +503,7 @@ efi_status_t efi_init_variables(void);
> void efi_variables_boot_exit_notify(void);
> efi_status_t efi_tcg2_notify_exit_boot_services_failed(void);
> /* Measure efi application invocation */
> -efi_status_t efi_tcg2_measure_efi_app_invocation(void);
> +efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *handle);
> /* Measure efi application exit */
> efi_status_t efi_tcg2_measure_efi_app_exit(void);
> /* Called by bootefi to initialize root node */
> @@ -845,6 +845,7 @@ struct efi_device_path *efi_dp_from_lo(struct efi_load_option *lo,
> efi_uintn_t *size, efi_guid_t guid);
> struct efi_device_path *efi_dp_concat(const struct efi_device_path *dp1,
> const struct efi_device_path *dp2);
> +struct efi_device_path *search_gpt_dp_node(struct efi_device_path *device_path);
> efi_status_t efi_deserialize_load_option(struct efi_load_option *lo, u8 *data,
> efi_uintn_t *size);
> unsigned long efi_serialize_load_option(struct efi_load_option *lo, u8 **data);
> diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h
> index ca66695b39..50a59f9263 100644
> --- a/include/efi_tcg2.h
> +++ b/include/efi_tcg2.h
> @@ -225,6 +225,18 @@ struct smbios_handoff_table_pointers2 {
> struct efi_configuration_table table_entry[];
> } __packed;
>
> +/**
> + * struct tdUEFI_GPT_DATA - event log structure of industry standard tables
> + * @uefi_partition_header: gpt partition header
> + * @number_of_partitions: the number of partition
> + * @partitions: partition entries
> + */
> +struct efi_gpt_data {
> + gpt_header uefi_partition_header;
> + u64 number_of_partitions;
> + gpt_entry partitions[];
> +} __packed;
> +
> struct efi_tcg2_protocol {
> efi_status_t (EFIAPI * get_capability)(struct efi_tcg2_protocol *this,
> struct efi_tcg2_boot_service_capability *capability);
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 701e2212c8..bf5661e1ee 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -3003,7 +3003,7 @@ efi_status_t EFIAPI efi_start_image(efi_handle_t image_handle,
>
> if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
> if (image_obj->image_type == IMAGE_SUBSYSTEM_EFI_APPLICATION) {
> - ret = efi_tcg2_measure_efi_app_invocation();
> + ret = efi_tcg2_measure_efi_app_invocation(image_obj);
> if (ret != EFI_SUCCESS) {
> log_warning("tcg2 measurement fails(0x%lx)\n",
> ret);
> diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
> index cbdb466da4..6aec64f373 100644
> --- a/lib/efi_loader/efi_device_path.c
> +++ b/lib/efi_loader/efi_device_path.c
> @@ -1294,3 +1294,30 @@ efi_device_path *efi_dp_from_lo(struct efi_load_option *lo,
>
> return NULL;
> }
> +
> +/**
> + * search_gpt_dp_node() - search gpt device path node
> + *
> + * @device_path: device path
> + *
> + * Return: pointer to the gpt device path node
> + */
> +struct efi_device_path *search_gpt_dp_node(struct efi_device_path *device_path)
You are not adding the function to an include. So it should be static.
> +{
> + struct efi_device_path *dp = device_path;
> +
> + while (dp) {
> + if (dp->type == DEVICE_PATH_TYPE_MEDIA_DEVICE &&
> + dp->sub_type == DEVICE_PATH_SUB_TYPE_HARD_DRIVE_PATH) {
> + struct efi_device_path_hard_drive_path *hd_dp =
> + (struct efi_device_path_hard_drive_path *)dp;
> +
> + if (hd_dp->partmap_type == PART_FORMAT_GPT &&
> + hd_dp->signature_type == SIG_TYPE_GUID)
> + return dp;
> + }
> + dp = efi_dp_next(dp);
> + }
> +
> + return NULL;
> +}
> diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> index f14d4d6da1..28e0362bf2 100644
> --- a/lib/efi_loader/efi_tcg2.c
> +++ b/lib/efi_loader/efi_tcg2.c
> @@ -1531,12 +1531,169 @@ static void *find_smbios_table(void)
> return NULL;
> }
>
> +static void *allocate_io_aligned_buf(void **buf, u32 size, u32 io_align)
> +{
Using memalign() avoids having two pointers and obsoletes this function.
> + if (!buf)
> + return NULL;
> +
> + *buf = calloc(1, size);
To create an aligned buffer with size bytes you would have to use size +
io_align - 1.
Best regards
Heinrich
> + if (!*buf)
> + return NULL;
> +
> + return (void *)PTR_ALIGN((uintptr_t)*buf, io_align);
> +}
> +
> +/**
> + * tcg2_measure_gpt_table() - measure gpt table
> + *
> + * @dev: TPM device
> + * @loaded_image: handle to the loaded image
> + *
> + * Return: status code
> + */
> +static efi_status_t
> +tcg2_measure_gpt_data(struct udevice *dev,
> + struct efi_loaded_image_obj *loaded_image)
> +{
> + efi_status_t ret;
> + efi_handle_t handle;
> + struct efi_handler *dp_handler;
> + struct efi_device_path *orig_device_path;
> + struct efi_device_path *device_path;
> + struct efi_device_path *dp;
> + struct efi_block_io *block_io;
> + struct efi_gpt_data *event = NULL;
> + efi_guid_t null_guid = NULL_GUID;
> + void *orig_gpt_h = NULL;
> + void *orig_gpt_e = NULL;
> + gpt_header *gpt_h = NULL;
> + gpt_entry *entry = NULL;
> + gpt_entry *gpt_e;
> + u32 num_of_valid_entry = 0;
> + u32 event_size;
> + u32 i;
> + u32 total_gpt_entry_size;
> +
> + ret = efi_search_protocol(&loaded_image->header,
> + &efi_guid_loaded_image_device_path,
> + &dp_handler);
> + if (ret != EFI_SUCCESS)
> + return ret;
> +
> + orig_device_path = dp_handler->protocol_interface;
> + device_path = efi_dp_dup(orig_device_path);
> + if (!device_path)
> + return EFI_OUT_OF_RESOURCES;
> +
> + dp = search_gpt_dp_node(device_path);
> + if (!dp) {
> + /* no GPT device path node found, skip GPT measurement */
> + ret = EFI_SUCCESS;
> + goto out1;
> + }
> +
> + /* read GPT header */
> + dp->type = DEVICE_PATH_TYPE_END;
> + dp->sub_type = DEVICE_PATH_SUB_TYPE_END;
> + dp = device_path;
> + ret = EFI_CALL(systab.boottime->locate_device_path(&efi_block_io_guid,
> + &dp, &handle));
> + if (ret != EFI_SUCCESS)
> + goto out1;
> +
> + ret = EFI_CALL(efi_handle_protocol(handle,
> + &efi_block_io_guid, (void **)&block_io));
> + if (ret != EFI_SUCCESS)
> + goto out1;
> +
> + gpt_h = allocate_io_aligned_buf(&orig_gpt_h,
> + block_io->media->block_size +
> + block_io->media->io_align,
> + block_io->media->io_align);
> + if (!orig_gpt_h || !gpt_h) {
> + ret = EFI_OUT_OF_RESOURCES;
> + goto out2;
> + }
> +
> + ret = block_io->read_blocks(block_io, block_io->media->media_id, 1,
> + block_io->media->block_size, gpt_h);
> + if (ret != EFI_SUCCESS)
> + goto out2;
> +
> + /* read GPT entry */
> + total_gpt_entry_size = gpt_h->num_partition_entries *
> + gpt_h->sizeof_partition_entry;
> + entry = allocate_io_aligned_buf(&orig_gpt_e,
> + total_gpt_entry_size +
> + block_io->media->io_align,
> + block_io->media->io_align);
> + if (!orig_gpt_e || !entry) {
> + ret = EFI_OUT_OF_RESOURCES;
> + goto out2;
> + }
> +
> + ret = block_io->read_blocks(block_io, block_io->media->media_id,
> + gpt_h->partition_entry_lba,
> + total_gpt_entry_size, entry);
> + if (ret != EFI_SUCCESS)
> + goto out2;
> +
> + /* count valid GPT entry */
> + gpt_e = entry;
> + for (i = 0; i < gpt_h->num_partition_entries; i++) {
> + if (guidcmp(&null_guid, &gpt_e->partition_type_guid))
> + num_of_valid_entry++;
> +
> + gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
> + }
> +
> + /* prepare event data for measurement */
> + event_size = sizeof(struct efi_gpt_data) +
> + (num_of_valid_entry * gpt_h->sizeof_partition_entry);
> + event = calloc(1, event_size);
> + if (!event) {
> + ret = EFI_OUT_OF_RESOURCES;
> + goto out2;
> + }
> + memcpy(event, gpt_h, sizeof(gpt_header));
> + put_unaligned_le64(num_of_valid_entry, &event->number_of_partitions);
> +
> + /* copy valid GPT entry */
> + gpt_e = entry;
> + num_of_valid_entry = 0;
> + for (i = 0; i < gpt_h->num_partition_entries; i++) {
> + if (guidcmp(&null_guid, &gpt_e->partition_type_guid)) {
> + memcpy((u8 *)event->partitions +
> + (num_of_valid_entry * gpt_h->sizeof_partition_entry),
> + gpt_e, gpt_h->sizeof_partition_entry);
> + num_of_valid_entry++;
> + }
> +
> + gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
> + }
> +
> + ret = tcg2_measure_event(dev, 5, EV_EFI_GPT_EVENT, event_size, (u8 *)event);
> + if (ret != EFI_SUCCESS)
> + goto out2;
> +
> +out2:
> + EFI_CALL(efi_close_protocol((efi_handle_t)block_io, &efi_block_io_guid,
> + NULL, NULL));
> + free(orig_gpt_h);
> + free(orig_gpt_e);
> + free(event);
> +out1:
> + efi_free_pool(device_path);
> +
> + return ret;
> +}
> +
> /**
> * efi_tcg2_measure_efi_app_invocation() - measure efi app invocation
> *
> * Return: status code
> */
> -efi_status_t efi_tcg2_measure_efi_app_invocation(void)
> +efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *handle)
> {
> efi_status_t ret;
> u32 pcr_index;
> @@ -1568,6 +1725,10 @@ efi_status_t efi_tcg2_measure_efi_app_invocation(void)
> goto out;
> }
>
> + ret = tcg2_measure_gpt_data(dev, handle);
> + if (ret != EFI_SUCCESS)
> + goto out;
> +
> for (pcr_index = 0; pcr_index <= 7; pcr_index++) {
> ret = tcg2_measure_event(dev, pcr_index, EV_SEPARATOR,
> sizeof(event), (u8 *)&event);
>
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