efi/libstub: Use TPM event typedefs from the TCG PC Client spec

Our efi_tcg2_tagged_event is not defined in the EFI spec, but it is not
a local invention either: it was taken from the TCG PC Client spec,
where it is called TCG_PCClientTaggedEvent.

Note that this spec also contains some guidance on how to populate it,
which is not being followed closely at the moment; it claims that the
event size should cover the TCG_PCClientTaggedEvent and its payload
only, but it currently covers the preceding efi_tcg2_event too.

However, this directly contradicts the TCG EFI protocol specification,
which states very clearly that the event size should cover the entire
data structure, including the leading efi_tcg2_event_t struct.

So rename the struct and document its provenance, but retain the
existing logic to populate the size field.

Link: https://lore.kernel.org/all/20240308085754.476197-8-ardb+git@google.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index c04b82ea40f2..043a3ff435f3 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -843,14 +843,14 @@ struct efi_tcg2_event {
 	/* u8[] event follows here */
 } __packed;
 
-struct efi_tcg2_tagged_event {
-	u32 tagged_event_id;
-	u32 tagged_event_data_size;
-	/* u8  tagged event data follows here */
-} __packed;
+/* from TCG PC Client Platform Firmware Profile Specification */
+typedef struct tdTCG_PCClientTaggedEvent {
+	u32	tagged_event_id;
+	u32	tagged_event_data_size;
+	u8	tagged_event_data[];
+} TCG_PCClientTaggedEvent;
 
 typedef struct efi_tcg2_event efi_tcg2_event_t;
-typedef struct efi_tcg2_tagged_event efi_tcg2_tagged_event_t;
 typedef union efi_tcg2_protocol efi_tcg2_protocol_t;
 
 union efi_tcg2_protocol {