Re: [PATCH v3 2/3] efi_loader: add UEFI GPT measurement

[Masahisa Kojima <masahisa.kojima@linaro.org>]

On Sat, 2 Oct 2021 at 01:28, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>
>
>
> 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@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.

I added the function in efi_loader.h
---
diff --git a/include/efi_loader.h b/include/efi_loader.h
+struct efi_device_path *search_gpt_dp_node(struct efi_device_path
*device_path);
---

>
> > +{
> > +     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.

Thank you, I will use memalign().

Regards,
Masahisa Kojima

>
> > +     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);
> >