Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 9336ffd..436d177 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Originally from efivars.c
  *
  * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
  * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/capability.h>
@@ -318,7 +305,12 @@
 static efi_status_t
 check_var_size(u32 attributes, unsigned long size)
 {
-	const struct efivar_operations *fops = __efivars->ops;
+	const struct efivar_operations *fops;
+
+	if (!__efivars)
+		return EFI_UNSUPPORTED;
+
+	fops = __efivars->ops;
 
 	if (!fops->query_variable_store)
 		return EFI_UNSUPPORTED;
@@ -329,7 +321,12 @@
 static efi_status_t
 check_var_size_nonblocking(u32 attributes, unsigned long size)
 {
-	const struct efivar_operations *fops = __efivars->ops;
+	const struct efivar_operations *fops;
+
+	if (!__efivars)
+		return EFI_UNSUPPORTED;
+
+	fops = __efivars->ops;
 
 	if (!fops->query_variable_store)
 		return EFI_UNSUPPORTED;
@@ -429,13 +426,18 @@
 int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
 		void *data, bool duplicates, struct list_head *head)
 {
-	const struct efivar_operations *ops = __efivars->ops;
+	const struct efivar_operations *ops;
 	unsigned long variable_name_size = 1024;
 	efi_char16_t *variable_name;
 	efi_status_t status;
 	efi_guid_t vendor_guid;
 	int err = 0;
 
+	if (!__efivars)
+		return -EFAULT;
+
+	ops = __efivars->ops;
+
 	variable_name = kzalloc(variable_name_size, GFP_KERNEL);
 	if (!variable_name) {
 		printk(KERN_ERR "efivars: Memory allocation failed.\n");
@@ -583,12 +585,14 @@
  */
 int __efivar_entry_delete(struct efivar_entry *entry)
 {
-	const struct efivar_operations *ops = __efivars->ops;
 	efi_status_t status;
 
-	status = ops->set_variable(entry->var.VariableName,
-				   &entry->var.VendorGuid,
-				   0, 0, NULL);
+	if (!__efivars)
+		return -EINVAL;
+
+	status = __efivars->ops->set_variable(entry->var.VariableName,
+					      &entry->var.VendorGuid,
+					      0, 0, NULL);
 
 	return efi_status_to_err(status);
 }
@@ -607,12 +611,17 @@
  */
 int efivar_entry_delete(struct efivar_entry *entry)
 {
-	const struct efivar_operations *ops = __efivars->ops;
+	const struct efivar_operations *ops;
 	efi_status_t status;
 
 	if (down_interruptible(&efivars_lock))
 		return -EINTR;
 
+	if (!__efivars) {
+		up(&efivars_lock);
+		return -EINVAL;
+	}
+	ops = __efivars->ops;
 	status = ops->set_variable(entry->var.VariableName,
 				   &entry->var.VendorGuid,
 				   0, 0, NULL);
@@ -650,13 +659,19 @@
 int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
 		     unsigned long size, void *data, struct list_head *head)
 {
-	const struct efivar_operations *ops = __efivars->ops;
+	const struct efivar_operations *ops;
 	efi_status_t status;
 	efi_char16_t *name = entry->var.VariableName;
 	efi_guid_t vendor = entry->var.VendorGuid;
 
 	if (down_interruptible(&efivars_lock))
 		return -EINTR;
+
+	if (!__efivars) {
+		up(&efivars_lock);
+		return -EINVAL;
+	}
+	ops = __efivars->ops;
 	if (head && efivar_entry_find(name, vendor, head, false)) {
 		up(&efivars_lock);
 		return -EEXIST;
@@ -687,12 +702,17 @@
 efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
 			     u32 attributes, unsigned long size, void *data)
 {
-	const struct efivar_operations *ops = __efivars->ops;
+	const struct efivar_operations *ops;
 	efi_status_t status;
 
 	if (down_trylock(&efivars_lock))
 		return -EBUSY;
 
+	if (!__efivars) {
+		up(&efivars_lock);
+		return -EINVAL;
+	}
+
 	status = check_var_size_nonblocking(attributes,
 					    size + ucs2_strsize(name, 1024));
 	if (status != EFI_SUCCESS) {
@@ -700,6 +720,7 @@
 		return -ENOSPC;
 	}
 
+	ops = __efivars->ops;
 	status = ops->set_variable_nonblocking(name, &vendor, attributes,
 					       size, data);
 
@@ -727,9 +748,13 @@
 int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
 			  bool block, unsigned long size, void *data)
 {
-	const struct efivar_operations *ops = __efivars->ops;
+	const struct efivar_operations *ops;
 	efi_status_t status;
 
+	if (!__efivars)
+		return -EINVAL;
+
+	ops = __efivars->ops;
 	if (!ops->query_variable_store)
 		return -ENOSYS;
 
@@ -829,13 +854,18 @@
  */
 int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
 {
-	const struct efivar_operations *ops = __efivars->ops;
+	const struct efivar_operations *ops;
 	efi_status_t status;
 
 	*size = 0;
 
 	if (down_interruptible(&efivars_lock))
 		return -EINTR;
+	if (!__efivars) {
+		up(&efivars_lock);
+		return -EINVAL;
+	}
+	ops = __efivars->ops;
 	status = ops->get_variable(entry->var.VariableName,
 				   &entry->var.VendorGuid, NULL, size, NULL);
 	up(&efivars_lock);
@@ -861,12 +891,14 @@
 int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
 		       unsigned long *size, void *data)
 {
-	const struct efivar_operations *ops = __efivars->ops;
 	efi_status_t status;
 
-	status = ops->get_variable(entry->var.VariableName,
-				   &entry->var.VendorGuid,
-				   attributes, size, data);
+	if (!__efivars)
+		return -EINVAL;
+
+	status = __efivars->ops->get_variable(entry->var.VariableName,
+					      &entry->var.VendorGuid,
+					      attributes, size, data);
 
 	return efi_status_to_err(status);
 }
@@ -882,14 +914,19 @@
 int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
 		     unsigned long *size, void *data)
 {
-	const struct efivar_operations *ops = __efivars->ops;
 	efi_status_t status;
 
 	if (down_interruptible(&efivars_lock))
 		return -EINTR;
-	status = ops->get_variable(entry->var.VariableName,
-				   &entry->var.VendorGuid,
-				   attributes, size, data);
+
+	if (!__efivars) {
+		up(&efivars_lock);
+		return -EINVAL;
+	}
+
+	status = __efivars->ops->get_variable(entry->var.VariableName,
+					      &entry->var.VendorGuid,
+					      attributes, size, data);
 	up(&efivars_lock);
 
 	return efi_status_to_err(status);
@@ -921,7 +958,7 @@
 int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
 			      unsigned long *size, void *data, bool *set)
 {
-	const struct efivar_operations *ops = __efivars->ops;
+	const struct efivar_operations *ops;
 	efi_char16_t *name = entry->var.VariableName;
 	efi_guid_t *vendor = &entry->var.VendorGuid;
 	efi_status_t status;
@@ -940,6 +977,11 @@
 	if (down_interruptible(&efivars_lock))
 		return -EINTR;
 
+	if (!__efivars) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	/*
 	 * Ensure that the available space hasn't shrunk below the safe level
 	 */
@@ -956,6 +998,8 @@
 		}
 	}
 
+	ops = __efivars->ops;
+
 	status = ops->set_variable(name, vendor, attributes, *size, data);
 	if (status != EFI_SUCCESS) {
 		err = efi_status_to_err(status);