ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
};
+static struct efivars __efivars;
+
#define PSTORE_EFI_ATTRIBUTES \
(EFI_VARIABLE_NON_VOLATILE | \
EFI_VARIABLE_BOOTSERVICE_ACCESS | \
efi_char16_t *variable_name,
efi_guid_t *vendor_guid);
+/*
+ * Prototype for workqueue functions updating sysfs entry
+ */
+
+static void efivar_update_sysfs_entries(struct work_struct *);
+static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries);
+static bool efivar_wq_enabled = true;
+
/* Return the number of unicode characters in data */
static unsigned long
utf16_strnlen(efi_char16_t *s, size_t maxlength)
check_var_size_locked(struct efivars *efivars, u32 attributes,
unsigned long size)
{
- u64 storage_size, remaining_size, max_size;
- efi_status_t status;
const struct efivar_operations *fops = efivars->ops;
- if (!efivars->ops->query_variable_info)
+ if (!efivars->ops->query_variable_store)
return EFI_UNSUPPORTED;
- status = fops->query_variable_info(attributes, &storage_size,
- &remaining_size, &max_size);
-
- if (status != EFI_SUCCESS)
- return status;
-
- if (!storage_size || size > remaining_size || size > max_size ||
- (remaining_size - size) < (storage_size / 2))
- return EFI_OUT_OF_RESOURCES;
-
- return status;
+ return fops->query_variable_store(attributes, size);
}
static ssize_t
spin_lock_irqsave(&efivars->lock, flags);
- /*
- * Check if there is a space enough to log.
- * size: a size of logging data
- * DUMP_NAME_LEN * 2: a maximum size of variable name
- */
+ if (size) {
+ /*
+ * Check if there is a space enough to log.
+ * size: a size of logging data
+ * DUMP_NAME_LEN * 2: a maximum size of variable name
+ */
- status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES,
- size + DUMP_NAME_LEN * 2);
+ status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES,
+ size + DUMP_NAME_LEN * 2);
- if (status) {
- spin_unlock_irqrestore(&efivars->lock, flags);
- *id = part;
- return -ENOSPC;
+ if (status) {
+ spin_unlock_irqrestore(&efivars->lock, flags);
+ *id = part;
+ return -ENOSPC;
+ }
}
for (i = 0; i < DUMP_NAME_LEN; i++)
if (found)
efivar_unregister(found);
- if (size)
- ret = efivar_create_sysfs_entry(efivars,
- utf16_strsize(efi_name,
- DUMP_NAME_LEN * 2),
- efi_name, &vendor);
+ if (efivar_wq_enabled)
+ schedule_work(&efivar_work);
*id = part;
return ret;
return count;
}
+static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor)
+{
+ struct efivar_entry *entry, *n;
+ struct efivars *efivars = &__efivars;
+ unsigned long strsize1, strsize2;
+ bool found = false;
+
+ strsize1 = utf16_strsize(variable_name, 1024);
+ list_for_each_entry_safe(entry, n, &efivars->list, list) {
+ strsize2 = utf16_strsize(entry->var.VariableName, 1024);
+ if (strsize1 == strsize2 &&
+ !memcmp(variable_name, &(entry->var.VariableName),
+ strsize2) &&
+ !efi_guidcmp(entry->var.VendorGuid,
+ *vendor)) {
+ found = true;
+ break;
+ }
+ }
+ return found;
+}
+
+/*
+ * Returns the size of variable_name, in bytes, including the
+ * terminating NULL character, or variable_name_size if no NULL
+ * character is found among the first variable_name_size bytes.
+ */
+static unsigned long var_name_strnsize(efi_char16_t *variable_name,
+ unsigned long variable_name_size)
+{
+ unsigned long len;
+ efi_char16_t c;
+
+ /*
+ * The variable name is, by definition, a NULL-terminated
+ * string, so make absolutely sure that variable_name_size is
+ * the value we expect it to be. If not, return the real size.
+ */
+ for (len = 2; len <= variable_name_size; len += sizeof(c)) {
+ c = variable_name[(len / sizeof(c)) - 1];
+ if (!c)
+ break;
+ }
+
+ return min(len, variable_name_size);
+}
+
+static void efivar_update_sysfs_entries(struct work_struct *work)
+{
+ struct efivars *efivars = &__efivars;
+ efi_guid_t vendor;
+ efi_char16_t *variable_name;
+ unsigned long variable_name_size = 1024;
+ efi_status_t status = EFI_NOT_FOUND;
+ bool found;
+
+ /* Add new sysfs entries */
+ while (1) {
+ variable_name = kzalloc(variable_name_size, GFP_KERNEL);
+ if (!variable_name) {
+ pr_err("efivars: Memory allocation failed.\n");
+ return;
+ }
+
+ spin_lock_irq(&efivars->lock);
+ found = false;
+ while (1) {
+ variable_name_size = 1024;
+ status = efivars->ops->get_next_variable(
+ &variable_name_size,
+ variable_name,
+ &vendor);
+ if (status != EFI_SUCCESS) {
+ break;
+ } else {
+ if (!variable_is_present(variable_name,
+ &vendor)) {
+ found = true;
+ break;
+ }
+ }
+ }
+ spin_unlock_irq(&efivars->lock);
+
+ if (!found) {
+ kfree(variable_name);
+ break;
+ } else {
+ variable_name_size = var_name_strnsize(variable_name,
+ variable_name_size);
+ efivar_create_sysfs_entry(efivars,
+ variable_name_size,
+ variable_name, &vendor);
+ }
+ }
+}
+
/*
* Let's not leave out systab information that snuck into
* the efivars driver
}
EXPORT_SYMBOL_GPL(unregister_efivars);
+/*
+ * Print a warning when duplicate EFI variables are encountered and
+ * disable the sysfs workqueue since the firmware is buggy.
+ */
+static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid,
+ unsigned long len16)
+{
+ size_t i, len8 = len16 / sizeof(efi_char16_t);
+ char *s8;
+
+ /*
+ * Disable the workqueue since the algorithm it uses for
+ * detecting new variables won't work with this buggy
+ * implementation of GetNextVariableName().
+ */
+ efivar_wq_enabled = false;
+
+ s8 = kzalloc(len8, GFP_KERNEL);
+ if (!s8)
+ return;
+
+ for (i = 0; i < len8; i++)
+ s8[i] = s16[i];
+
+ printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
+ s8, vendor_guid);
+ kfree(s8);
+}
+
int register_efivars(struct efivars *efivars,
const struct efivar_operations *ops,
struct kobject *parent_kobj)
&vendor_guid);
switch (status) {
case EFI_SUCCESS:
+ variable_name_size = var_name_strnsize(variable_name,
+ variable_name_size);
+
+ /*
+ * Some firmware implementations return the
+ * same variable name on multiple calls to
+ * get_next_variable(). Terminate the loop
+ * immediately as there is no guarantee that
+ * we'll ever see a different variable name,
+ * and may end up looping here forever.
+ */
+ if (variable_is_present(variable_name, &vendor_guid)) {
+ dup_variable_bug(variable_name, &vendor_guid,
+ variable_name_size);
+ status = EFI_NOT_FOUND;
+ break;
+ }
+
efivar_create_sysfs_entry(efivars,
variable_name_size,
variable_name,
}
EXPORT_SYMBOL_GPL(register_efivars);
-static struct efivars __efivars;
static struct efivar_operations ops;
/*
ops.get_variable = efi.get_variable;
ops.set_variable = efi.set_variable;
ops.get_next_variable = efi.get_next_variable;
- ops.query_variable_info = efi.query_variable_info;
+ ops.query_variable_store = efi_query_variable_store;
error = register_efivars(&__efivars, &ops, efi_kobj);
if (error)
goto err_put;
static void __exit
efivars_exit(void)
{
+ cancel_work_sync(&efivar_work);
+
if (efi_enabled(EFI_RUNTIME_SERVICES)) {
unregister_efivars(&__efivars);
kobject_put(efi_kobj);
git.openpandora.org / pandora-kernel.git / blobdiff