[PATCH 3/3] efi: add EFI_DEBUG_IMAGE_INFO for debug
Heinrich Schuchardt
xypron.glpk at gmx.de
Mon Apr 28 12:40:46 CEST 2025
On 4/23/25 23:31, Ying-Chun Liu (PaulLiu) wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paul.liu at linaro.org>
>
> This commit adds the functionality of generate EFI_DEBUG_IMAGE_INFO
> while loading the image.
>
> This feature is described in UEFI Spec 2.10. Section 18.4.3.
>
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu at linaro.org>
> Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> ---
> include/efi_api.h | 2 +
> include/efi_loader.h | 5 ++
> lib/efi_loader/efi_boottime.c | 136 ++++++++++++++++++++++++++++++++++
> 3 files changed, 143 insertions(+)
>
> diff --git a/include/efi_api.h b/include/efi_api.h
> index 0f4245091f1..ba87af17c1f 100644
> --- a/include/efi_api.h
> +++ b/include/efi_api.h
> @@ -571,6 +571,8 @@ struct efi_loaded_image {
> #define EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS 0x01
> #define EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED 0x02
>
> +#define EFI_DEBUG_IMAGE_INFO_TYPE_NORMAL 0x01
> +
> struct efi_debug_image_info_normal {
> u32 image_info_type;
> struct efi_loaded_image *loaded_image_protocol_instance;
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 370bc042f70..babe23a8a83 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -617,6 +617,11 @@ efi_status_t efi_root_node_register(void);
> efi_status_t efi_initialize_system_table(void);
> /* Called by bootefi to initialize debug */
> efi_status_t efi_initialize_system_table_pointer(void);
> +/* Called by efi_load_image for register debug info */
> +void efi_core_new_debug_image_info_entry(u32 image_info_type,
> + struct efi_loaded_image *loaded_image,
> + efi_handle_t image_handle);
> +void efi_core_remove_debug_image_info_entry(efi_handle_t image_handle);
> /* efi_runtime_detach() - detach unimplemented runtime functions */
> void efi_runtime_detach(void);
> /* efi_convert_pointer() - convert pointer to virtual address */
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index e2665459e44..bf37580c06b 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -2130,6 +2130,12 @@ efi_status_t EFIAPI efi_load_image(bool boot_policy,
> *image_handle = NULL;
> free(info);
> }
> +
> + if (*image_handle) {
> + efi_core_new_debug_image_info_entry(EFI_DEBUG_IMAGE_INFO_TYPE_NORMAL,
> + info,
> + *image_handle);
> + }
> error:
> return EFI_EXIT(ret);
> }
> @@ -3359,6 +3365,7 @@ efi_status_t EFIAPI efi_unload_image(efi_handle_t image_handle)
> ret = EFI_INVALID_PARAMETER;
> goto out;
> }
> + efi_core_remove_debug_image_info_entry(image_handle);
> switch (efiobj->type) {
> case EFI_OBJECT_TYPE_STARTED_IMAGE:
> /* Call the unload function */
> @@ -4045,6 +4052,10 @@ efi_m_debug_info_table_header = {
> NULL
> };
>
> +static u32 efi_m_max_table_entries;
> +
> +#define EFI_DEBUG_TABLE_ENTRY_SIZE (sizeof(void *))
> +
> const efi_guid_t efi_debug_image_info_table_guid =
> EFI_DEBUG_IMAGE_INFO_TABLE_GUID;
>
> @@ -4095,3 +4106,128 @@ efi_status_t efi_initialize_system_table_pointer(void)
>
> return ret;
> }
> +
> +/**
> + * Add a new efi_loaded_image structure to the efi_debug_image_info Table.
> + * Re-Allocates the table if it's not large enough to accomidate another
> + * entry.
> + *
> + * @param image_info_type type of debug image information
> + * @param loaded_image pointer to the loaded image protocol for the image
> + * being loaded
> + * @param image_handle image handle for the image being loaded
> + **/
> +void efi_core_new_debug_image_info_entry(u32 image_info_type,
> + struct efi_loaded_image *loaded_image,
> + efi_handle_t image_handle)
> +{
> + union efi_debug_image_info *table;
> + union efi_debug_image_info *new_table;
> + u32 index;
> + u32 table_size;
> +
> + /* Set the flag indicating that we're in the process of updating
> + * the table.
> + */
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +
> + table = efi_m_debug_info_table_header.efi_debug_image_info_table;
> +
> + if (efi_m_debug_info_table_header.table_size < efi_m_max_table_entries) {
> + /* We still have empty entries in the Table, find the first
> + * empty entry.
> + */
> + index = 0;
> + while (table[index].normal_image)
> + index++;
> + } else {
> + /* table is full, re-allocate another page for a larger
> + * table.
> + */
> + table_size = efi_m_max_table_entries * EFI_DEBUG_TABLE_ENTRY_SIZE;
> + efi_allocate_pool(EFI_RUNTIME_SERVICES_DATA,
> + table_size + EFI_PAGE_SIZE,
> + (void **)&new_table);
> +
> + if (!new_table) {
> + efi_m_debug_info_table_header.update_status &=
> + ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> + return;
> + }
> +
> + memset(new_table, 0, table_size + EFI_PAGE_SIZE);
> +
> + /* Copy the old table into the new one. */
> + memcpy(new_table, table, table_size);
> + /* Free the old table. */
> + efi_free_pool(table);
> + /* Update the table header. */
> + table = new_table;
> + efi_m_debug_info_table_header.efi_debug_image_info_table =
> + new_table;
> +
> + /* Enlarge the max table entries and set the first empty
> + * entry index to be the original max table entries.
> + */
> + index = efi_m_max_table_entries;
> + efi_m_max_table_entries +=
> + EFI_PAGE_SIZE / EFI_DEBUG_TABLE_ENTRY_SIZE;
> + }
> +
> + /* Allocate data for new entry. */
> + efi_allocate_pool(EFI_RUNTIME_SERVICES_DATA,
> + sizeof(struct efi_debug_image_info_normal),
> + (void **)(&table[index].normal_image));
> + if (table[index].normal_image) {
> + /* Update the entry. */
> + table[index].normal_image->image_info_type = image_info_type;
> + table[index].normal_image->loaded_image_protocol_instance =
> + loaded_image;
> + table[index].normal_image->image_handle = image_handle;
> +
> + /* Increase the number of EFI_DEBUG_IMAGE_INFO elements and
> + * set the efi_m_debug_info_table_header in modified status.
> + */
> + efi_m_debug_info_table_header.table_size++;
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;
> + }
> +
> + efi_m_debug_info_table_header.update_status &=
> + ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +}
> +
> +void efi_core_remove_debug_image_info_entry(efi_handle_t image_handle)
> +{
> + union efi_debug_image_info *table;
> + u32 index;
> +
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +
> + table = efi_m_debug_info_table_header.efi_debug_image_info_table;
> +
> + for (index = 0; index < efi_m_max_table_entries; index++) {
> + if (table[index].normal_image &&
> + table[index].normal_image->image_handle == image_handle) {
> + /* Found a match. Free up the record, then NULL the
> + * pointer to indicate the slot is free.
> + */
> + efi_free_pool(table[index].normal_image);
> + table[index].normal_image = NULL;
It seems that you just copied the logic from EDK II instead of
programming according to the UEFI specification.
I cannot see that the UEFI specification allows NULL pointers inside the
array.
> +
> + /* Decrease the number of EFI_DEBUG_IMAGE_INFO
> + * elements and set the efi_m_debug_info_table_header
> + * in modified status.
> + */
> + efi_m_debug_info_table_header.table_size--;
According to the UEFI specification the table_size must match the array
size and not the number of non-NULL elements. If there is a NULL pointer
in the middle of the table and you decrease the table_size value, the
last non-NULL element is not accessible anymore.
A correct implementation would move all elements after the deleted one
one slot to the front.
Best regards
Heinrich
> + efi_m_debug_info_table_header.update_status |=
> + EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;
> + break;
> + }
> + }
> +
> + efi_m_debug_info_table_header.update_status &=
> + ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS;
> +}
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