efivars: Use local variables instead of a pointer dereference

In order to support a compat interface we need to stop passing pointers
to structures around, since the type of structure is going to depend on
whether the current task is a compat task.

Cc: Mike Waychison <mikew@google.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 35 insertions, 13 deletions

diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 50ea412a25e6..06ec6ee1c58a 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -197,37 +197,48 @@ static ssize_t
 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
 {
         struct efi_variable *new_var, *var = &entry->var;
+        efi_char16_t *name;
+        unsigned long size;
+        efi_guid_t vendor;
+        u32 attributes;
+        u8 *data;
         int err;
 
         if (count != sizeof(struct efi_variable))
                 return -EINVAL;
 
         new_var = (struct efi_variable *)buf;
+
+        attributes = new_var->Attributes;
+        vendor = new_var->VendorGuid;
+        name = new_var->VariableName;
+        size = new_var->DataSize;
+        data = new_var->Data;
+
         /*
          * If only updating the variable data, then the name
          * and guid should remain the same
          */
-        if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) ||
-                efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) {
+        if (memcmp(name, var->VariableName, sizeof(var->VariableName)) ||
+                efi_guidcmp(vendor, var->VendorGuid)) {
                 printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
                 return -EINVAL;
         }
 
-        if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
+        if ((size <= 0) || (attributes == 0)){
                 printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
                 return -EINVAL;
         }
 
-        if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
-            efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
+        if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
+            efivar_validate(new_var, data, size) == false) {
                 printk(KERN_ERR "efivars: Malformed variable content\n");
                 return -EINVAL;
         }
 
         memcpy(&entry->var, new_var, count);
 
-        err = efivar_entry_set(entry, new_var->Attributes,
-                               new_var->DataSize, new_var->Data, NULL);
+        err = efivar_entry_set(entry, attributes, size, data, NULL);
         if (err) {
                 printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err);
                 return -EIO;
@@ -328,13 +339,20 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
 {
         struct efi_variable *new_var = (struct efi_variable *)buf;
         struct efivar_entry *new_entry;
+        unsigned long size;
+        u32 attributes;
+        u8 *data;
         int err;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
-        if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
-            efivar_validate(new_var, new_var->Data, new_var->DataSize) == false) {
+        attributes = new_var->Attributes;
+        size = new_var->DataSize;
+        data = new_var->Data;
+
+        if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
+            efivar_validate(new_var, data, size) == false) {
                 printk(KERN_ERR "efivars: Malformed variable content\n");
                 return -EINVAL;
         }
@@ -345,8 +363,8 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
 
         memcpy(&new_entry->var, new_var, sizeof(*new_var));
 
-        err = efivar_entry_set(new_entry, new_var->Attributes, new_var->DataSize,
-                               new_var->Data, &efivar_sysfs_list);
+        err = efivar_entry_set(new_entry, attributes, size,
+                               data, &efivar_sysfs_list);
         if (err) {
                 if (err == -EEXIST)
                         err = -EINVAL;
@@ -370,14 +388,18 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
 {
         struct efi_variable *del_var = (struct efi_variable *)buf;
         struct efivar_entry *entry;
+        efi_char16_t *name;
+        efi_guid_t vendor;
         int err = 0;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
+        name = del_var->VariableName;
+        vendor = del_var->VendorGuid;
+
         efivar_entry_iter_begin();
-        entry = efivar_entry_find(del_var->VariableName, del_var->VendorGuid,
-                                  &efivar_sysfs_list, true);
+        entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true);
         if (!entry)
                 err = -EINVAL;
         else if (__efivar_entry_delete(entry))