pstore: Replace arguments for read() API

The argument list for the pstore_read() interface is unwieldy. This changes
passes the new struct pstore_record instead. The erst backend was already
doing something similar internally.

Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 43 insertions, 61 deletions

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index f402ba2eed46..bda24129e85b 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -28,26 +28,16 @@ static int efi_pstore_close(struct pstore_info *psi)
 	return 0;
 }
 
-struct pstore_read_data {
-	u64 *id;
-	enum pstore_type_id *type;
-	int *count;
-	struct timespec *timespec;
-	bool *compressed;
-	ssize_t *ecc_notice_size;
-	char **buf;
-};
-
 static inline u64 generic_id(unsigned long timestamp,
 			     unsigned int part, int count)
 {
 	return ((u64) timestamp * 100 + part) * 1000 + count;
 }
 
-static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
+static int efi_pstore_read_func(struct efivar_entry *entry,
+				struct pstore_record *record)
 {
 	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
-	struct pstore_read_data *cb_data = data;
 	char name[DUMP_NAME_LEN], data_type;
 	int i;
 	int cnt;
@@ -61,37 +51,37 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
 		name[i] = entry->var.VariableName[i];
 
 	if (sscanf(name, "dump-type%u-%u-%d-%lu-%c",
-		   cb_data->type, &part, &cnt, &time, &data_type) == 5) {
-		*cb_data->id = generic_id(time, part, cnt);
-		*cb_data->count = cnt;
-		cb_data->timespec->tv_sec = time;
-		cb_data->timespec->tv_nsec = 0;
+		   &record->type, &part, &cnt, &time, &data_type) == 5) {
+		record->id = generic_id(time, part, cnt);
+		record->count = cnt;
+		record->time.tv_sec = time;
+		record->time.tv_nsec = 0;
 		if (data_type == 'C')
-			*cb_data->compressed = true;
+			record->compressed = true;
 		else
-			*cb_data->compressed = false;
-		*cb_data->ecc_notice_size = 0;
+			record->compressed = false;
+		record->ecc_notice_size = 0;
 	} else if (sscanf(name, "dump-type%u-%u-%d-%lu",
-		   cb_data->type, &part, &cnt, &time) == 4) {
-		*cb_data->id = generic_id(time, part, cnt);
-		*cb_data->count = cnt;
-		cb_data->timespec->tv_sec = time;
-		cb_data->timespec->tv_nsec = 0;
-		*cb_data->compressed = false;
-		*cb_data->ecc_notice_size = 0;
+		   &record->type, &part, &cnt, &time) == 4) {
+		record->id = generic_id(time, part, cnt);
+		record->count = cnt;
+		record->time.tv_sec = time;
+		record->time.tv_nsec = 0;
+		record->compressed = false;
+		record->ecc_notice_size = 0;
 	} else if (sscanf(name, "dump-type%u-%u-%lu",
-			  cb_data->type, &part, &time) == 3) {
+			  &record->type, &part, &time) == 3) {
 		/*
 		 * Check if an old format,
 		 * which doesn't support holding
 		 * multiple logs, remains.
 		 */
-		*cb_data->id = generic_id(time, part, 0);
-		*cb_data->count = 0;
-		cb_data->timespec->tv_sec = time;
-		cb_data->timespec->tv_nsec = 0;
-		*cb_data->compressed = false;
-		*cb_data->ecc_notice_size = 0;
+		record->id = generic_id(time, part, 0);
+		record->count = 0;
+		record->time.tv_sec = time;
+		record->time.tv_nsec = 0;
+		record->compressed = false;
+		record->ecc_notice_size = 0;
 	} else
 		return 0;
 
@@ -99,7 +89,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
 	__efivar_entry_get(entry, &entry->var.Attributes,
 			   &entry->var.DataSize, entry->var.Data);
 	size = entry->var.DataSize;
-	memcpy(*cb_data->buf, entry->var.Data,
+	memcpy(record->buf, entry->var.Data,
 	       (size_t)min_t(unsigned long, EFIVARS_DATA_SIZE_MAX, size));
 
 	return size;
@@ -164,7 +154,7 @@ static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
 /**
  * efi_pstore_sysfs_entry_iter
  *
- * @data: function-specific data to pass to callback
+ * @record: pstore record to pass to callback
  * @pos: entry to begin iterating from
  *
  * You MUST call efivar_enter_iter_begin() before this function, and
@@ -175,7 +165,8 @@ static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
  * the next entry of the last one passed to efi_pstore_read_func().
  * To begin iterating from the beginning of the list @pos must be %NULL.
  */
-static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
+static int efi_pstore_sysfs_entry_iter(struct pstore_record *record,
+				       struct efivar_entry **pos)
 {
 	struct efivar_entry *entry, *n;
 	struct list_head *head = &efivar_sysfs_list;
@@ -186,7 +177,7 @@ static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
 		list_for_each_entry_safe(entry, n, head, list) {
 			efi_pstore_scan_sysfs_enter(entry, n, head);
 
-			size = efi_pstore_read_func(entry, data);
+			size = efi_pstore_read_func(entry, record);
 			ret = efi_pstore_scan_sysfs_exit(entry, n, head,
 							 size < 0);
 			if (ret)
@@ -201,7 +192,7 @@ static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
 	list_for_each_entry_safe_from((*pos), n, head, list) {
 		efi_pstore_scan_sysfs_enter((*pos), n, head);
 
-		size = efi_pstore_read_func((*pos), data);
+		size = efi_pstore_read_func((*pos), record);
 		ret = efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
 		if (ret)
 			return ret;
@@ -225,36 +216,27 @@ static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
  * size < 0: Failed to get data of entry logging via efi_pstore_write(),
  *           and pstore will stop reading entry.
  */
-static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
-			       int *count, struct timespec *timespec,
-			       char **buf, bool *compressed,
-			       ssize_t *ecc_notice_size,
-			       struct pstore_info *psi)
+static ssize_t efi_pstore_read(struct pstore_record *record)
 {
-	struct pstore_read_data data;
+	struct efivar_entry *entry = (struct efivar_entry *)record->psi->data;
 	ssize_t size;
 
-	data.id = id;
-	data.type = type;
-	data.count = count;
-	data.timespec = timespec;
-	data.compressed = compressed;
-	data.ecc_notice_size = ecc_notice_size;
-	data.buf = buf;
-
-	*data.buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
-	if (!*data.buf)
+	record->buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
+	if (!record->buf)
 		return -ENOMEM;
 
 	if (efivar_entry_iter_begin()) {
-		kfree(*data.buf);
-		return -EINTR;
+		size = -EINTR;
+		goto out;
 	}
-	size = efi_pstore_sysfs_entry_iter(&data,
-					   (struct efivar_entry **)&psi->data);
+	size = efi_pstore_sysfs_entry_iter(record, &entry);
 	efivar_entry_iter_end();
-	if (size <= 0)
-		kfree(*data.buf);
+
+out:
+	if (size <= 0) {
+		kfree(record->buf);
+		record->buf = NULL;
+	}
 	return size;
 }