[coreboot-gerrit] Change in coreboot[master]: security/tpm: Include mrc.bin in CRTM if present

[Bill XIE (Code Review)]

Bill XIE has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/38858 )

Change subject: security/tpm: Include mrc.bin in CRTM if present
......................................................................

security/tpm: Include mrc.bin in CRTM if present

mrc.bin, on platforms where it presents, is code executed on CPU, so
it should be considered a part of CRTM.

cbfs_locate_file_in_region() is hooked to measurement here too, since
mrc.bin is loaded with it, and CBFS_TYPE_MRC (the type of mrc.bin) is
measured to TPM_CRTM_PCR rather than TPM_RUNTIME_DATA_PCR.

TODO: I have heard that SMM is too resource-limited to link with vboot
library, so currently tspi_measure_cbfs_hook() is masked in SMM.
Please correct me if I am wrong.

Change-Id: Ib4c3cf47b919864056baf725001ca8a4aaafa110
Signed-off-by: Bill XIE 
---
M src/lib/cbfs.c
M src/security/tpm/tspi/crtm.c
M src/security/tpm/tspi/crtm.h
3 files changed, 16 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/58/38858/1

diff --git a/src/lib/cbfs.c b/src/lib/cbfs.c
index 517f59d..f9d9af4 100644
--- a/src/lib/cbfs.c
+++ b/src/lib/cbfs.c
@@ -58,7 +58,11 @@
    	 * Files can be added to the RO_REGION_ONLY config option to use this feature.
    	 */
    	printk(BIOS_DEBUG, "Fall back to RO region for %s\n", name);
-		ret = cbfs_locate_file_in_region(fh, "COREBOOT", name, type);
+		if (fmap_locate_area_as_rdev("COREBOOT", &rdev))
+			ERROR("RO region not found\n");
+		else
+			ret = cbfs_locate(fh, &rdev, name, type);
+
    }

if (!ret)
@@ -95,7 +99,11 @@
    	return -1;
    }

-	return cbfs_locate(fh, &rdev, name, type);
+	int ret = cbfs_locate(fh, &rdev, name, type);
+	if (!ret)
+		if (tspi_measure_cbfs_hook(fh, name))
+			return -1;
+	return ret;
 }

size_t cbfs_load_and_decompress(const struct region_device *rdev, size_t offset,
diff --git a/src/security/tpm/tspi/crtm.c b/src/security/tpm/tspi/crtm.c
index 89c53a1..1c5438d 100644
--- a/src/security/tpm/tspi/crtm.c
+++ b/src/security/tpm/tspi/crtm.c
@@ -133,10 +133,14 @@
    cbfs_file_data(&rdev, fh);

switch (cbfs_type) {
-	case CBFS_TYPE_MRC:
    case CBFS_TYPE_MRC_CACHE:
    	pcr_index = TPM_RUNTIME_DATA_PCR;
    	break;
+	/*
+	 * mrc.bin is code executed on CPU, so it
+	 * should not be considered runtime data
+	 */
+	case CBFS_TYPE_MRC:
    case CBFS_TYPE_STAGE:
    case CBFS_TYPE_SELF:
    case CBFS_TYPE_FIT:
diff --git a/src/security/tpm/tspi/crtm.h b/src/security/tpm/tspi/crtm.h
index 2c2f18b..8899498 100644
--- a/src/security/tpm/tspi/crtm.h
+++ b/src/security/tpm/tspi/crtm.h
@@ -46,7 +46,7 @@
  */
 uint32_t tspi_init_crtm(void);

-#if CONFIG(TPM_MEASURED_BOOT)
+#if !ENV_SMM && CONFIG(TPM_MEASURED_BOOT)
 /*
  * Measures cbfs data via hook (cbfs)
  * fh is the cbfs file handle to measure