[PATCH v5 2/3] tcg2: decouple eventlog size from efi

Ilias Apalodimas ilias.apalodimas at linaro.org
Thu Jan 16 15:00:38 CET 2025


On Tue, 14 Jan 2025 at 17:20, Raymond Mao <raymond.mao at linaro.org> wrote:
>
> Move default eventlog size from efi to tpm for using in both
> efi and measured boot.
>
> Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
> ---
> Changes in v5
> - Move eventlog size kconfig from EFI to TPM2, so that it can be used by
>   both EFI and MEASURED_BOOT.
>
>  doc/usage/measured_boot.rst |  1 -
>  drivers/tpm/Kconfig         |  9 +++++++++
>  include/efi_tcg2.h          |  2 --
>  lib/efi_loader/Kconfig      |  9 ---------
>  lib/efi_loader/efi_tcg2.c   | 15 ++++++++-------
>  5 files changed, 17 insertions(+), 19 deletions(-)
>
> diff --git a/doc/usage/measured_boot.rst b/doc/usage/measured_boot.rst
> index 05c439e9ac..488dd546f1 100644
> --- a/doc/usage/measured_boot.rst
> +++ b/doc/usage/measured_boot.rst
> @@ -24,7 +24,6 @@ Requirements
>
>  * A hardware TPM 2.0 supported by an enabled U-Boot driver
>  * CONFIG_EFI_TCG2_PROTOCOL=y
> -* CONFIG_EFI_TCG2_PROTOCOL_EVENTLOG_SIZE=y
>  * optional CONFIG_EFI_TCG2_PROTOCOL_MEASURE_DTB=y will measure the loaded DTB
>    in PCR 1
>
> diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
> index d59102d9a6..01bc686d36 100644
> --- a/drivers/tpm/Kconfig
> +++ b/drivers/tpm/Kconfig
> @@ -209,6 +209,15 @@ config TPM2_MMIO
>           to the device using the standard TPM Interface Specification (TIS)
>           protocol.
>
> +config TPM2_EVENT_LOG_SIZE
> +       int "EventLog size"
> +       depends on TPM_V2
> +       default 65536
> +       help
> +         Define the size of the EventLog. Note that this is going to be
> +         allocated twice. One for the eventlog it self and one for the
> +         configuration table that is required from the TCG2 spec
> +
>  endif # TPM_V2
>
>  endmenu
> diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h
> index 8dfb1bc952..7ed8880991 100644
> --- a/include/efi_tcg2.h
> +++ b/include/efi_tcg2.h
> @@ -28,8 +28,6 @@
>  #define EFI_TCG2_MAX_PCR_INDEX 23
>  #define EFI_TCG2_FINAL_EVENTS_TABLE_VERSION 1
>
> -#define TPM2_EVENT_LOG_SIZE CONFIG_EFI_TCG2_PROTOCOL_EVENTLOG_SIZE
> -
>  typedef u32 efi_tcg_event_log_bitmap;
>  typedef u32 efi_tcg_event_log_format;
>  typedef u32 efi_tcg_event_algorithm_bitmap;
> diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> index c46ffe3a9d..d703e901ed 100644
> --- a/lib/efi_loader/Kconfig
> +++ b/lib/efi_loader/Kconfig
> @@ -437,15 +437,6 @@ config EFI_TCG2_PROTOCOL
>           Provide a EFI_TCG2_PROTOCOL implementation using the TPM hardware
>           of the platform.
>
> -config EFI_TCG2_PROTOCOL_EVENTLOG_SIZE
> -       int "EFI_TCG2_PROTOCOL EventLog size"
> -       depends on EFI_TCG2_PROTOCOL
> -       default 65536
> -       help
> -               Define the size of the EventLog for EFI_TCG2_PROTOCOL. Note that
> -               this is going to be allocated twice. One for the eventlog it self
> -               and one for the configuration table that is required from the spec
> -
>  config EFI_TCG2_PROTOCOL_MEASURE_DTB
>         bool "Measure DTB with EFI_TCG2_PROTOCOL"
>         depends on EFI_TCG2_PROTOCOL
> diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> index a15c73162e..6dba8b1406 100644
> --- a/lib/efi_loader/efi_tcg2.c
> +++ b/lib/efi_loader/efi_tcg2.c
> @@ -111,7 +111,7 @@ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type,
>         /* if ExitBootServices hasn't been called update the normal log */
>         if (!event_log.ebs_called) {
>                 if (event_log.truncated ||
> -                   event_log.pos + event_size > TPM2_EVENT_LOG_SIZE) {
> +                   event_log.pos + event_size > CONFIG_TPM2_EVENT_LOG_SIZE) {
>                         event_log.truncated = true;
>                         return EFI_VOLUME_FULL;
>                 }
> @@ -124,7 +124,7 @@ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type,
>                 return ret;
>
>         /* if GetEventLog has been called update FinalEventLog as well */
> -       if (event_log.final_pos + event_size > TPM2_EVENT_LOG_SIZE)
> +       if (event_log.final_pos + event_size > CONFIG_TPM2_EVENT_LOG_SIZE)
>                 return EFI_VOLUME_FULL;
>
>         log = (void *)((uintptr_t)event_log.final_buffer + event_log.final_pos);
> @@ -822,12 +822,12 @@ static efi_status_t create_final_event(void)
>          * EFI_TCG2_GET_EVENT_LOGS need to be stored in an instance of an
>          * EFI_CONFIGURATION_TABLE
>          */
> -       ret = efi_allocate_pool(EFI_ACPI_MEMORY_NVS, TPM2_EVENT_LOG_SIZE,
> +       ret = efi_allocate_pool(EFI_ACPI_MEMORY_NVS, CONFIG_TPM2_EVENT_LOG_SIZE,
>                                 &event_log.final_buffer);
>         if (ret != EFI_SUCCESS)
>                 goto out;
>
> -       memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE);
> +       memset(event_log.final_buffer, 0xff, CONFIG_TPM2_EVENT_LOG_SIZE);
>         final_event = event_log.final_buffer;
>         final_event->number_of_events = 0;
>         final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION;
> @@ -913,7 +913,8 @@ static efi_status_t efi_init_event_log(void)
>         if (tcg2_platform_get_tpm2(&dev))
>                 return EFI_DEVICE_ERROR;
>
> -       ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, TPM2_EVENT_LOG_SIZE,
> +       ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA,
> +                               CONFIG_TPM2_EVENT_LOG_SIZE,
>                                 (void **)&event_log.buffer);
>         if (ret != EFI_SUCCESS)
>                 return ret;
> @@ -922,7 +923,7 @@ static efi_status_t efi_init_event_log(void)
>          * initialize log area as 0xff so the OS can easily figure out the
>          * last log entry
>          */
> -       memset(event_log.buffer, 0xff, TPM2_EVENT_LOG_SIZE);
> +       memset(event_log.buffer, 0xff, CONFIG_TPM2_EVENT_LOG_SIZE);
>
>         /*
>          * The log header is defined to be in SHA1 event log entry format.
> @@ -939,7 +940,7 @@ static efi_status_t efi_init_event_log(void)
>          * platforms can use different ways to do so.
>          */
>         elog.log = event_log.buffer;
> -       elog.log_size = TPM2_EVENT_LOG_SIZE;
> +       elog.log_size = CONFIG_TPM2_EVENT_LOG_SIZE;
>         rc = tcg2_log_prepare_buffer(dev, &elog, false);
>         if (rc) {
>                 ret = (rc == -ENOBUFS) ? EFI_BUFFER_TOO_SMALL : EFI_DEVICE_ERROR;
> --
> 2.25.1
>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>


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