efivars: Add compatibility code for compat tasks

[cascardo/linux.git] / drivers / firmware / efi / efivars.c

diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index a44310c..463c565 100644 (file)
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -69,6 +69,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/ucs2_string.h>
+#include <linux/compat.h>
 
 #define EFIVARS_VERSION "0.08"
 #define EFIVARS_DATE "2004-May-17"
@@ -86,6 +87,15 @@ static struct kset *efivars_kset;
 static struct bin_attribute *efivars_new_var;
 static struct bin_attribute *efivars_del_var;
 
+struct compat_efi_variable {
+       efi_char16_t  VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)];
+       efi_guid_t    VendorGuid;
+       __u32         DataSize;
+       __u8          Data[1024];
+       __u32         Status;
+       __u32         Attributes;
+} __packed;
+
 struct efivar_attribute {
        struct attribute attr;
        ssize_t (*show) (struct efivar_entry *entry, char *buf);
@@ -218,6 +228,25 @@ sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor,
        return 0;
 }
 
+static inline bool is_compat(void)
+{
+       if (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())
+               return true;
+
+       return false;
+}
+
+static void
+copy_out_compat(struct efi_variable *dst, struct compat_efi_variable *src)
+{
+       memcpy(dst->VariableName, src->VariableName, EFI_VAR_NAME_LEN);
+       memcpy(dst->Data, src->Data, sizeof(src->Data));
+
+       dst->VendorGuid = src->VendorGuid;
+       dst->DataSize = src->DataSize;
+       dst->Attributes = src->Attributes;
+}
+
 /*
  * We allow each variable to be edited via rewriting the
  * entire efi variable structure.
@@ -233,22 +262,42 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
        u8 *data;
        int err;
 
-       if (count != sizeof(struct efi_variable))
-               return -EINVAL;
+       if (is_compat()) {
+               struct compat_efi_variable *compat;
 
-       new_var = (struct efi_variable *)buf;
+               if (count != sizeof(*compat))
+                       return -EINVAL;
 
-       attributes = new_var->Attributes;
-       vendor = new_var->VendorGuid;
-       name = new_var->VariableName;
-       size = new_var->DataSize;
-       data = new_var->Data;
+               compat = (struct compat_efi_variable *)buf;
+               attributes = compat->Attributes;
+               vendor = compat->VendorGuid;
+               name = compat->VariableName;
+               size = compat->DataSize;
+               data = compat->Data;
 
-       err = sanity_check(var, name, vendor, size, attributes, data);
-       if (err)
-               return err;
+               err = sanity_check(var, name, vendor, size, attributes, data);
+               if (err)
+                       return err;
+
+               copy_out_compat(&entry->var, compat);
+       } else {
+               if (count != sizeof(struct efi_variable))
+                       return -EINVAL;
+
+               new_var = (struct efi_variable *)buf;
 
-       memcpy(&entry->var, new_var, count);
+               attributes = new_var->Attributes;
+               vendor = new_var->VendorGuid;
+               name = new_var->VariableName;
+               size = new_var->DataSize;
+               data = new_var->Data;
+
+               err = sanity_check(var, name, vendor, size, attributes, data);
+               if (err)
+                       return err;
+
+               memcpy(&entry->var, new_var, count);
+       }
 
        err = efivar_entry_set(entry, attributes, size, data, NULL);
        if (err) {
@@ -263,6 +312,8 @@ static ssize_t
 efivar_show_raw(struct efivar_entry *entry, char *buf)
 {
        struct efi_variable *var = &entry->var;
+       struct compat_efi_variable *compat;
+       size_t size;
 
        if (!entry || !buf)
                return 0;
@@ -272,9 +323,23 @@ efivar_show_raw(struct efivar_entry *entry, char *buf)
                             &entry->var.DataSize, entry->var.Data))
                return -EIO;
 
-       memcpy(buf, var, sizeof(*var));
+       if (is_compat()) {
+               compat = (struct compat_efi_variable *)buf;
+
+               size = sizeof(*compat);
+               memcpy(compat->VariableName, var->VariableName,
+                       EFI_VAR_NAME_LEN);
+               memcpy(compat->Data, var->Data, sizeof(compat->Data));
+
+               compat->VendorGuid = var->VendorGuid;
+               compat->DataSize = var->DataSize;
+               compat->Attributes = var->Attributes;
+       } else {
+               size = sizeof(*var);
+               memcpy(buf, var, size);
+       }
 
-       return sizeof(*var);
+       return size;
 }
 
 /*
@@ -349,8 +414,10 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
                             struct bin_attribute *bin_attr,
                             char *buf, loff_t pos, size_t count)
 {
+       struct compat_efi_variable *compat = (struct compat_efi_variable *)buf;
        struct efi_variable *new_var = (struct efi_variable *)buf;
        struct efivar_entry *new_entry;
+       bool need_compat = is_compat();
        efi_char16_t *name;
        unsigned long size;
        u32 attributes;
@@ -360,13 +427,23 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
 
-       if (count != sizeof(*new_var))
-               return -EINVAL;
-
-       attributes = new_var->Attributes;
-       name = new_var->VariableName;
-       size = new_var->DataSize;
-       data = new_var->Data;
+       if (need_compat) {
+               if (count != sizeof(*compat))
+                       return -EINVAL;
+
+               attributes = compat->Attributes;
+               name = compat->VariableName;
+               size = compat->DataSize;
+               data = compat->Data;
+       } else {
+               if (count != sizeof(*new_var))
+                       return -EINVAL;
+
+               attributes = new_var->Attributes;
+               name = new_var->VariableName;
+               size = new_var->DataSize;
+               data = new_var->Data;
+       }
 
        if ((attributes & ~EFI_VARIABLE_MASK) != 0 ||
            efivar_validate(name, data, size) == false) {
@@ -378,7 +455,10 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
        if (!new_entry)
                return -ENOMEM;
 
-       memcpy(&new_entry->var, new_var, sizeof(*new_var));
+       if (need_compat)
+               copy_out_compat(&new_entry->var, compat);
+       else
+               memcpy(&new_entry->var, new_var, sizeof(*new_var));
 
        err = efivar_entry_set(new_entry, attributes, size,
                               data, &efivar_sysfs_list);
@@ -404,6 +484,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
                             char *buf, loff_t pos, size_t count)
 {
        struct efi_variable *del_var = (struct efi_variable *)buf;
+       struct compat_efi_variable *compat;
        struct efivar_entry *entry;
        efi_char16_t *name;
        efi_guid_t vendor;
@@ -412,11 +493,20 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
 
-       if (count != sizeof(*del_var))
-               return -EINVAL;
+       if (is_compat()) {
+               if (count != sizeof(*compat))
+                       return -EINVAL;
+
+               compat = (struct compat_efi_variable *)buf;
+               name = compat->VariableName;
+               vendor = compat->VendorGuid;
+       } else {
+               if (count != sizeof(*del_var))
+                       return -EINVAL;
 
-       name = del_var->VariableName;
-       vendor = del_var->VendorGuid;
+               name = del_var->VariableName;
+               vendor = del_var->VendorGuid;
+       }
 
        efivar_entry_iter_begin();
        entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true);