1 files changed, 78 insertions, 28 deletions

diff --git a/src/drivers/mrc_cache/mrc_cache.c b/src/drivers/mrc_cache/mrc_cache.c
index d567a20f11..1b1ad6332f 100644
--- a/src/drivers/mrc_cache/mrc_cache.c
+++ b/src/drivers/mrc_cache/mrc_cache.c
@@ -204,23 +204,16 @@ static int mrc_header_valid(struct region_device *rdev, struct mrc_metadata *md)
 	return 0;
 }
 
-static int mrc_data_valid(const struct region_device *rdev,
-				const struct mrc_metadata *md)
+static int mrc_data_valid(const struct mrc_metadata *md,
+			  void *data, size_t data_size)
 {
-	void *data;
 	uint16_t checksum;
-	const size_t md_size = sizeof(*md);
-	const size_t data_size = md->data_size;
 
-	data = rdev_mmap(rdev, md_size, data_size);
-	if (data == NULL) {
-		printk(BIOS_ERR, "MRC: mmap failure on data verification.\n");
+	if (md->data_size != data_size)
 		return -1;
-	}
 
 	checksum = compute_ip_checksum(data, data_size);
 
-	rdev_munmap(rdev, data);
 	if (md->data_checksum != checksum) {
 		printk(BIOS_ERR, "MRC: data checksum mismatch: %x vs %x\n",
 			md->data_checksum, checksum);
@@ -230,7 +223,7 @@ static int mrc_data_valid(const struct region_device *rdev,
 	return 0;
 }
 
-static int mrc_cache_latest(const char *name,
+static int mrc_cache_get_latest_slot_info(const char *name,
 				const struct region_device *backing_rdev,
 				struct mrc_metadata *md,
 				struct region_file *cache_file,
@@ -260,25 +253,19 @@ static int mrc_cache_latest(const char *name,
 		return fail_bad_data ? -1 : 0;
 	}
 
-	/* Validate Data */
-	if (mrc_data_valid(rdev, md) < 0) {
-		printk(BIOS_ERR, "MRC: invalid data in '%s'\n", name);
-		return fail_bad_data ? -1 : 0;
-	}
-
 	return 0;
 }
 
-int mrc_cache_get_current(int type, uint32_t version,
-				struct region_device *rdev)
+static int mrc_cache_find_current(int type, uint32_t version,
+				  struct region_device *rdev,
+				  struct mrc_metadata *md)
 {
 	const struct cache_region *cr;
 	struct region region;
 	struct region_device read_rdev;
 	struct region_file cache_file;
-	struct mrc_metadata md;
 	size_t data_size;
-	const size_t md_size = sizeof(md);
+	const size_t md_size = sizeof(*md);
 	const bool fail_bad_data = true;
 
 	cr = lookup_region(&region, type);
@@ -289,21 +276,75 @@ int mrc_cache_get_current(int type, uint32_t version,
 	if (boot_device_ro_subregion(&region, &read_rdev) < 0)
 		return -1;
 
-	if (mrc_cache_latest(cr->name, &read_rdev, &md, &cache_file, rdev,
-		fail_bad_data) < 0)
+	if (mrc_cache_get_latest_slot_info(cr->name,
+					   &read_rdev,
+					   md,
+					   &cache_file,
+					   rdev,
+					   fail_bad_data) < 0)
 		return -1;
 
-	if (version != md.version) {
+	if (version != md->version) {
 		printk(BIOS_INFO, "MRC: version mismatch: %x vs %x\n",
-			md.version, version);
+			md->version, version);
 		return -1;
 	}
 
 	/* Re-size rdev to only contain the data. i.e. remove metadata. */
-	data_size = md.data_size;
+	data_size = md->data_size;
 	return rdev_chain(rdev, rdev, md_size, data_size);
 }
 
+int mrc_cache_load_current(int type, uint32_t version, void *buffer,
+			   size_t buffer_size)
+{
+	struct region_device rdev;
+	struct mrc_metadata md;
+	size_t data_size;
+
+	if (mrc_cache_find_current(type, version, &rdev, &md) < 0)
+		return -1;
+
+	data_size = region_device_sz(&rdev);
+	if (buffer_size < data_size)
+		return -1;
+
+	if (rdev_readat(&rdev, buffer, 0, data_size) != data_size)
+		return -1;
+
+	if (mrc_data_valid(&md, buffer, data_size) < 0)
+		return -1;
+
+	return 0;
+}
+
+void *mrc_cache_current_mmap_leak(int type, uint32_t version,
+				  size_t *data_size)
+{
+	struct region_device rdev;
+	void *data;
+	size_t region_device_size;
+	struct mrc_metadata md;
+
+	if (mrc_cache_find_current(type, version, &rdev, &md) < 0)
+		return NULL;
+
+	region_device_size = region_device_sz(&rdev);
+	if (data_size)
+		*data_size = region_device_size;
+	data = rdev_mmap_full(&rdev);
+
+	if (data == NULL) {
+		printk(BIOS_INFO, "MRC: mmap failure.\n");
+		return NULL;
+	}
+
+	if (mrc_data_valid(&md, data, region_device_size) < 0)
+		return NULL;
+
+	return data;
+}
+
 static bool mrc_cache_needs_update(const struct region_device *rdev,
 				const struct cbmem_entry *to_be_updated)
 {
@@ -392,8 +433,17 @@ static void update_mrc_cache_by_type(int type)
 	if (backing_rdev == NULL)
 		return;
 
-	if (mrc_cache_latest(cr->name, backing_rdev, &md, &cache_file,
-		&latest_rdev, fail_bad_data) < 0)
+	/* Note that mrc_cache_get_latest_slot_info doesn't check the
+	 * validity of the current slot.  If the slot is invalid,
+	 * we'll overwrite it anyway when we update the mrc_cache.
+	 */
+	if (mrc_cache_get_latest_slot_info(cr->name,
+					   backing_rdev,
+					   &md,
+					   &cache_file,
+					   &latest_rdev,
+					   fail_bad_data) < 0)
+
 		return;
 
 	if (!mrc_cache_needs_update(&latest_rdev, to_be_updated)) {