pstore: Replace arguments for erase() API

This removes the argument list for the erase() callback and replaces it
with a pointer to the backend record details to be removed.
Signed-off-by: Kees Cook <keescook@chromium.org>

drivers/acpi/apei/erst.c

@@ -927,8 +927,7 @@ static int erst_open_pstore(struct pstore_info *psi);
 static int erst_close_pstore(struct pstore_info *psi);
 static ssize_t erst_reader(struct pstore_record *record);
 static int erst_writer(struct pstore_record *record);
-static int erst_clearer(enum pstore_type_id type, u64 id, int count,
-			struct timespec time, struct pstore_info *psi);
+static int erst_clearer(struct pstore_record *record);
 
 static struct pstore_info erst_info = {
 	.owner		= THIS_MODULE,
@@ -1100,10 +1099,9 @@ static int erst_writer(struct pstore_record *record)
 	return ret;
 }
 
-static int erst_clearer(enum pstore_type_id type, u64 id, int count,
-			struct timespec time, struct pstore_info *psi)
+static int erst_clearer(struct pstore_record *record)
 {
-	return erst_clear(id);
+	return erst_clear(record->id);
 }
 
 static int __init erst_init(void)

drivers/firmware/efi/efi-pstore.c

@@ -266,10 +266,7 @@ static int efi_pstore_write(struct pstore_record *record)
 };
 
 struct pstore_erase_data {
-	u64 id;
-	enum pstore_type_id type;
-	int count;
-	struct timespec time;
+	struct pstore_record *record;
 	efi_char16_t *name;
 };
 
@@ -295,8 +292,9 @@ static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
 		 * Check if an old format, which doesn't support
 		 * holding multiple logs, remains.
 		 */
-		sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
-			(unsigned int)ed->id, ed->time.tv_sec);
+		snprintf(name_old, sizeof(name_old), "dump-type%u-%u-%lu",
+			ed->record->type, (unsigned int)ed->record->id,
+			ed->record->time.tv_sec);
 
 		for (i = 0; i < DUMP_NAME_LEN; i++)
 			efi_name_old[i] = name_old[i];
@@ -321,8 +319,7 @@ static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
 	return 1;
 }
 
-static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
-			    struct timespec time, struct pstore_info *psi)
+static int efi_pstore_erase(struct pstore_record *record)
 {
 	struct pstore_erase_data edata;
 	struct efivar_entry *entry = NULL;
@@ -331,17 +328,16 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
 	int found, i;
 	unsigned int part;
 
-	do_div(id, 1000);
-	part = do_div(id, 100);
-	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, time.tv_sec);
+	do_div(record->id, 1000);
+	part = do_div(record->id, 100);
+	snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lu",
+		 record->type, record->part, record->count,
+		 record->time.tv_sec);
 
 	for (i = 0; i < DUMP_NAME_LEN; i++)
 		efi_name[i] = name[i];
 
-	edata.id = part;
-	edata.type = type;
-	edata.count = count;
-	edata.time = time;
+	edata.record = record;
 	edata.name = efi_name;
 
 	if (efivar_entry_iter_begin())

fs/pstore/inode.c

@@ -210,14 +210,12 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 	if (err)
 		return err;
 
-	if (record->psi->erase) {
+	if (!record->psi->erase)
+		return -EPERM;
+
 	mutex_lock(&record->psi->read_mutex);
-		record->psi->erase(record->type, record->id, record->count,
-			      d_inode(dentry)->i_ctime, record->psi);
+	record->psi->erase(record);
 	mutex_unlock(&record->psi->read_mutex);
-	} else {
-		return -EPERM;
-	}
 
 	return simple_unlink(dir, dentry);
 }

fs/pstore/ram.c

@@ -469,25 +469,24 @@ static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
 	return -EINVAL;
 }
 
-static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
-				struct timespec time, struct pstore_info *psi)
+static int ramoops_pstore_erase(struct pstore_record *record)
 {
-	struct ramoops_context *cxt = psi->data;
+	struct ramoops_context *cxt = record->psi->data;
 	struct persistent_ram_zone *prz;
 
-	switch (type) {
+	switch (record->type) {
 	case PSTORE_TYPE_DMESG:
-		if (id >= cxt->max_dump_cnt)
+		if (record->id >= cxt->max_dump_cnt)
 			return -EINVAL;
-		prz = cxt->dprzs[id];
+		prz = cxt->dprzs[record->id];
 		break;
 	case PSTORE_TYPE_CONSOLE:
 		prz = cxt->cprz;
 		break;
 	case PSTORE_TYPE_FTRACE:
-		if (id >= cxt->max_ftrace_cnt)
+		if (record->id >= cxt->max_ftrace_cnt)
 			return -EINVAL;
-		prz = cxt->fprzs[id];
+		prz = cxt->fprzs[record->id];
 		break;
 	case PSTORE_TYPE_PMSG:
 		prz = cxt->mprz;

include/linux/pstore.h

@@ -177,15 +177,11 @@ struct pstore_record {
  *
  * @erase:
  *	Delete a record from backend storage.  Different backends
- *	identify records differently, so all possible methods of
- *	identification are included to help the backend locate the
- *	record to remove.
+ *	identify records differently, so entire original record is
+ *	passed back to assist in identification of what the backend
+ *	should remove from storage.
  *
- *	@type:	in: pstore record type to write
- *	@id:	in: per-type unique identifier for the record
- *	@count:	in: Oops count
- *	@time:	in: timestamp for the record
- *	@psi:	in: pointer to the struct pstore_info for the backend
+ *	@record:	pointer to record metadata.
  *
  *	Returns 0 on success, and non-zero on error.
  *
@@ -215,9 +211,7 @@ struct pstore_info {
 			enum kmsg_dump_reason reason, u64 *id,
 			unsigned int part, const char __user *buf,
 			bool compressed, size_t size, struct pstore_info *psi);
-	int		(*erase)(enum pstore_type_id type, u64 id,
-			int count, struct timespec time,
-			struct pstore_info *psi);
+	int		(*erase)(struct pstore_record *record);
 };
 
 /* Supported frontends */