[PATCH 1/5] efivars: Use local variables instead of a pointer dereference

From: Matt Fleming
Date: Wed Mar 19 2014 - 16:02:07 EST


From: Matt Fleming <matt.fleming@xxxxxxxxx>

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.

Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
---
drivers/firmware/efi/efivars.c | 48 ++++++++++++++++++++++++++++++------------
1 file 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))
--
1.8.5.3

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