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Diffstat (limited to 'drivers/firmware/efivars.c')
-rw-r--r--drivers/firmware/efivars.c1262
1 files changed, 1262 insertions, 0 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
new file mode 100644
index 00000000..47408e80
--- /dev/null
+++ b/drivers/firmware/efivars.c
@@ -0,0 +1,1262 @@
+/*
+ * EFI Variables - efivars.c
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ *
+ * This code takes all variables accessible from EFI runtime and
+ * exports them via sysfs
+ *
+ * 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
+ *
+ * Changelog:
+ *
+ * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com>
+ * remove check for efi_enabled in exit
+ * add MODULE_VERSION
+ *
+ * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com>
+ * minor bug fixes
+ *
+ * 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com)
+ * converted driver to export variable information via sysfs
+ * and moved to drivers/firmware directory
+ * bumped revision number to v0.07 to reflect conversion & move
+ *
+ * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ * fix locking per Peter Chubb's findings
+ *
+ * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_unparse()
+ *
+ * 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com>
+ * use list_for_each_safe when deleting vars.
+ * remove ifdef CONFIG_SMP around include <linux/smp.h>
+ * v0.04 release to linux-ia64@linuxia64.org
+ *
+ * 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * Moved vars from /proc/efi to /proc/efi/vars, and made
+ * efi.c own the /proc/efi directory.
+ * v0.03 release to linux-ia64@linuxia64.org
+ *
+ * 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * At the request of Stephane, moved ownership of /proc/efi
+ * to efi.c, and now efivars lives under /proc/efi/vars.
+ *
+ * 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * Feedback received from Stephane Eranian incorporated.
+ * efivar_write() checks copy_from_user() return value.
+ * efivar_read/write() returns proper errno.
+ * v0.02 release to linux-ia64@linuxia64.org
+ *
+ * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com>
+ * v0.01 release to linux-ia64@linuxia64.org
+ */
+
+#include <linux/capability.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/smp.h>
+#include <linux/efi.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/pstore.h>
+
+#include <asm/uaccess.h>
+
+#define EFIVARS_VERSION "0.08"
+#define EFIVARS_DATE "2004-May-17"
+
+MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
+MODULE_DESCRIPTION("sysfs interface to EFI Variables");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(EFIVARS_VERSION);
+
+#define DUMP_NAME_LEN 52
+
+/*
+ * The maximum size of VariableName + Data = 1024
+ * Therefore, it's reasonable to save that much
+ * space in each part of the structure,
+ * and we use a page for reading/writing.
+ */
+
+struct efi_variable {
+ efi_char16_t VariableName[1024/sizeof(efi_char16_t)];
+ efi_guid_t VendorGuid;
+ unsigned long DataSize;
+ __u8 Data[1024];
+ efi_status_t Status;
+ __u32 Attributes;
+} __attribute__((packed));
+
+
+struct efivar_entry {
+ struct efivars *efivars;
+ struct efi_variable var;
+ struct list_head list;
+ struct kobject kobj;
+};
+
+struct efivar_attribute {
+ struct attribute attr;
+ ssize_t (*show) (struct efivar_entry *entry, char *buf);
+ ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count);
+};
+
+#define PSTORE_EFI_ATTRIBUTES \
+ (EFI_VARIABLE_NON_VOLATILE | \
+ EFI_VARIABLE_BOOTSERVICE_ACCESS | \
+ EFI_VARIABLE_RUNTIME_ACCESS)
+
+#define EFIVAR_ATTR(_name, _mode, _show, _store) \
+struct efivar_attribute efivar_attr_##_name = { \
+ .attr = {.name = __stringify(_name), .mode = _mode}, \
+ .show = _show, \
+ .store = _store, \
+};
+
+#define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr)
+#define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj)
+
+/*
+ * Prototype for sysfs creation function
+ */
+static int
+efivar_create_sysfs_entry(struct efivars *efivars,
+ unsigned long variable_name_size,
+ efi_char16_t *variable_name,
+ efi_guid_t *vendor_guid);
+
+/* Return the number of unicode characters in data */
+static unsigned long
+utf16_strnlen(efi_char16_t *s, size_t maxlength)
+{
+ unsigned long length = 0;
+
+ while (*s++ != 0 && length < maxlength)
+ length++;
+ return length;
+}
+
+static inline unsigned long
+utf16_strlen(efi_char16_t *s)
+{
+ return utf16_strnlen(s, ~0UL);
+}
+
+/*
+ * Return the number of bytes is the length of this string
+ * Note: this is NOT the same as the number of unicode characters
+ */
+static inline unsigned long
+utf16_strsize(efi_char16_t *data, unsigned long maxlength)
+{
+ return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t);
+}
+
+static inline int
+utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len)
+{
+ while (1) {
+ if (len == 0)
+ return 0;
+ if (*a < *b)
+ return -1;
+ if (*a > *b)
+ return 1;
+ if (*a == 0) /* implies *b == 0 */
+ return 0;
+ a++;
+ b++;
+ len--;
+ }
+}
+
+static bool
+validate_device_path(struct efi_variable *var, int match, u8 *buffer,
+ unsigned long len)
+{
+ struct efi_generic_dev_path *node;
+ int offset = 0;
+
+ node = (struct efi_generic_dev_path *)buffer;
+
+ if (len < sizeof(*node))
+ return false;
+
+ while (offset <= len - sizeof(*node) &&
+ node->length >= sizeof(*node) &&
+ node->length <= len - offset) {
+ offset += node->length;
+
+ if ((node->type == EFI_DEV_END_PATH ||
+ node->type == EFI_DEV_END_PATH2) &&
+ node->sub_type == EFI_DEV_END_ENTIRE)
+ return true;
+
+ node = (struct efi_generic_dev_path *)(buffer + offset);
+ }
+
+ /*
+ * If we're here then either node->length pointed past the end
+ * of the buffer or we reached the end of the buffer without
+ * finding a device path end node.
+ */
+ return false;
+}
+
+static bool
+validate_boot_order(struct efi_variable *var, int match, u8 *buffer,
+ unsigned long len)
+{
+ /* An array of 16-bit integers */
+ if ((len % 2) != 0)
+ return false;
+
+ return true;
+}
+
+static bool
+validate_load_option(struct efi_variable *var, int match, u8 *buffer,
+ unsigned long len)
+{
+ u16 filepathlength;
+ int i, desclength = 0, namelen;
+
+ namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName));
+
+ /* Either "Boot" or "Driver" followed by four digits of hex */
+ for (i = match; i < match+4; i++) {
+ if (var->VariableName[i] > 127 ||
+ hex_to_bin(var->VariableName[i] & 0xff) < 0)
+ return true;
+ }
+
+ /* Reject it if there's 4 digits of hex and then further content */
+ if (namelen > match + 4)
+ return false;
+
+ /* A valid entry must be at least 8 bytes */
+ if (len < 8)
+ return false;
+
+ filepathlength = buffer[4] | buffer[5] << 8;
+
+ /*
+ * There's no stored length for the description, so it has to be
+ * found by hand
+ */
+ desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
+
+ /* Each boot entry must have a descriptor */
+ if (!desclength)
+ return false;
+
+ /*
+ * If the sum of the length of the description, the claimed filepath
+ * length and the original header are greater than the length of the
+ * variable, it's malformed
+ */
+ if ((desclength + filepathlength + 6) > len)
+ return false;
+
+ /*
+ * And, finally, check the filepath
+ */
+ return validate_device_path(var, match, buffer + desclength + 6,
+ filepathlength);
+}
+
+static bool
+validate_uint16(struct efi_variable *var, int match, u8 *buffer,
+ unsigned long len)
+{
+ /* A single 16-bit integer */
+ if (len != 2)
+ return false;
+
+ return true;
+}
+
+static bool
+validate_ascii_string(struct efi_variable *var, int match, u8 *buffer,
+ unsigned long len)
+{
+ int i;
+
+ for (i = 0; i < len; i++) {
+ if (buffer[i] > 127)
+ return false;
+
+ if (buffer[i] == 0)
+ return true;
+ }
+
+ return false;
+}
+
+struct variable_validate {
+ char *name;
+ bool (*validate)(struct efi_variable *var, int match, u8 *data,
+ unsigned long len);
+};
+
+static const struct variable_validate variable_validate[] = {
+ { "BootNext", validate_uint16 },
+ { "BootOrder", validate_boot_order },
+ { "DriverOrder", validate_boot_order },
+ { "Boot*", validate_load_option },
+ { "Driver*", validate_load_option },
+ { "ConIn", validate_device_path },
+ { "ConInDev", validate_device_path },
+ { "ConOut", validate_device_path },
+ { "ConOutDev", validate_device_path },
+ { "ErrOut", validate_device_path },
+ { "ErrOutDev", validate_device_path },
+ { "Timeout", validate_uint16 },
+ { "Lang", validate_ascii_string },
+ { "PlatformLang", validate_ascii_string },
+ { "", NULL },
+};
+
+static bool
+validate_var(struct efi_variable *var, u8 *data, unsigned long len)
+{
+ int i;
+ u16 *unicode_name = var->VariableName;
+
+ for (i = 0; variable_validate[i].validate != NULL; i++) {
+ const char *name = variable_validate[i].name;
+ int match;
+
+ for (match = 0; ; match++) {
+ char c = name[match];
+ u16 u = unicode_name[match];
+
+ /* All special variables are plain ascii */
+ if (u > 127)
+ return true;
+
+ /* Wildcard in the matching name means we've matched */
+ if (c == '*')
+ return variable_validate[i].validate(var,
+ match, data, len);
+
+ /* Case sensitive match */
+ if (c != u)
+ break;
+
+ /* Reached the end of the string while matching */
+ if (!c)
+ return variable_validate[i].validate(var,
+ match, data, len);
+ }
+ }
+
+ return true;
+}
+
+static efi_status_t
+get_var_data_locked(struct efivars *efivars, struct efi_variable *var)
+{
+ efi_status_t status;
+
+ var->DataSize = 1024;
+ status = efivars->ops->get_variable(var->VariableName,
+ &var->VendorGuid,
+ &var->Attributes,
+ &var->DataSize,
+ var->Data);
+ return status;
+}
+
+static efi_status_t
+get_var_data(struct efivars *efivars, struct efi_variable *var)
+{
+ efi_status_t status;
+
+ spin_lock(&efivars->lock);
+ status = get_var_data_locked(efivars, var);
+ spin_unlock(&efivars->lock);
+
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
+ status);
+ }
+ return status;
+}
+
+static ssize_t
+efivar_guid_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ char *str = buf;
+
+ if (!entry || !buf)
+ return 0;
+
+ efi_guid_unparse(&var->VendorGuid, str);
+ str += strlen(str);
+ str += sprintf(str, "\n");
+
+ return str - buf;
+}
+
+static ssize_t
+efivar_attr_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ char *str = buf;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return -EINVAL;
+
+ status = get_var_data(entry->efivars, var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ if (var->Attributes & 0x1)
+ str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n");
+ if (var->Attributes & 0x2)
+ str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n");
+ if (var->Attributes & 0x4)
+ str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n");
+ return str - buf;
+}
+
+static ssize_t
+efivar_size_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ char *str = buf;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return -EINVAL;
+
+ status = get_var_data(entry->efivars, var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ str += sprintf(str, "0x%lx\n", var->DataSize);
+ return str - buf;
+}
+
+static ssize_t
+efivar_data_read(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return -EINVAL;
+
+ status = get_var_data(entry->efivars, var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ memcpy(buf, var->Data, var->DataSize);
+ return var->DataSize;
+}
+/*
+ * We allow each variable to be edited via rewriting the
+ * entire efi variable structure.
+ */
+static ssize_t
+efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
+{
+ struct efi_variable *new_var, *var = &entry->var;
+ struct efivars *efivars = entry->efivars;
+ efi_status_t status = EFI_NOT_FOUND;
+
+ if (count != sizeof(struct efi_variable))
+ return -EINVAL;
+
+ new_var = (struct efi_variable *)buf;
+ /*
+ * 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)) {
+ printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n");
+ return -EINVAL;
+ }
+
+ if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){
+ printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n");
+ return -EINVAL;
+ }
+
+ if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
+ validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
+ printk(KERN_ERR "efivars: Malformed variable content\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&efivars->lock);
+ status = efivars->ops->set_variable(new_var->VariableName,
+ &new_var->VendorGuid,
+ new_var->Attributes,
+ new_var->DataSize,
+ new_var->Data);
+
+ spin_unlock(&efivars->lock);
+
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
+ status);
+ return -EIO;
+ }
+
+ memcpy(&entry->var, new_var, count);
+ return count;
+}
+
+static ssize_t
+efivar_show_raw(struct efivar_entry *entry, char *buf)
+{
+ struct efi_variable *var = &entry->var;
+ efi_status_t status;
+
+ if (!entry || !buf)
+ return 0;
+
+ status = get_var_data(entry->efivars, var);
+ if (status != EFI_SUCCESS)
+ return -EIO;
+
+ memcpy(buf, var, sizeof(*var));
+ return sizeof(*var);
+}
+
+/*
+ * Generic read/write functions that call the specific functions of
+ * the attributes...
+ */
+static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ struct efivar_entry *var = to_efivar_entry(kobj);
+ struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
+ ssize_t ret = -EIO;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (efivar_attr->show) {
+ ret = efivar_attr->show(var, buf);
+ }
+ return ret;
+}
+
+static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ struct efivar_entry *var = to_efivar_entry(kobj);
+ struct efivar_attribute *efivar_attr = to_efivar_attr(attr);
+ ssize_t ret = -EIO;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (efivar_attr->store)
+ ret = efivar_attr->store(var, buf, count);
+
+ return ret;
+}
+
+static const struct sysfs_ops efivar_attr_ops = {
+ .show = efivar_attr_show,
+ .store = efivar_attr_store,
+};
+
+static void efivar_release(struct kobject *kobj)
+{
+ struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj);
+ kfree(var);
+}
+
+static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL);
+static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL);
+static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL);
+static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL);
+static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw);
+
+static struct attribute *def_attrs[] = {
+ &efivar_attr_guid.attr,
+ &efivar_attr_size.attr,
+ &efivar_attr_attributes.attr,
+ &efivar_attr_data.attr,
+ &efivar_attr_raw_var.attr,
+ NULL,
+};
+
+static struct kobj_type efivar_ktype = {
+ .release = efivar_release,
+ .sysfs_ops = &efivar_attr_ops,
+ .default_attrs = def_attrs,
+};
+
+static struct pstore_info efi_pstore_info;
+
+static inline void
+efivar_unregister(struct efivar_entry *var)
+{
+ kobject_put(&var->kobj);
+}
+
+#ifdef CONFIG_PSTORE
+
+static int efi_pstore_open(struct pstore_info *psi)
+{
+ struct efivars *efivars = psi->data;
+
+ spin_lock(&efivars->lock);
+ efivars->walk_entry = list_first_entry(&efivars->list,
+ struct efivar_entry, list);
+ return 0;
+}
+
+static int efi_pstore_close(struct pstore_info *psi)
+{
+ struct efivars *efivars = psi->data;
+
+ spin_unlock(&efivars->lock);
+ return 0;
+}
+
+static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
+ struct timespec *timespec,
+ char **buf, struct pstore_info *psi)
+{
+ efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
+ struct efivars *efivars = psi->data;
+ char name[DUMP_NAME_LEN];
+ int i;
+ unsigned int part, size;
+ unsigned long time;
+
+ while (&efivars->walk_entry->list != &efivars->list) {
+ if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid,
+ vendor)) {
+ for (i = 0; i < DUMP_NAME_LEN; i++) {
+ name[i] = efivars->walk_entry->var.VariableName[i];
+ }
+ if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) {
+ *id = part;
+ timespec->tv_sec = time;
+ timespec->tv_nsec = 0;
+ get_var_data_locked(efivars, &efivars->walk_entry->var);
+ size = efivars->walk_entry->var.DataSize;
+ *buf = kmalloc(size, GFP_KERNEL);
+ if (*buf == NULL)
+ return -ENOMEM;
+ memcpy(*buf, efivars->walk_entry->var.Data,
+ size);
+ efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
+ struct efivar_entry, list);
+ return size;
+ }
+ }
+ efivars->walk_entry = list_entry(efivars->walk_entry->list.next,
+ struct efivar_entry, list);
+ }
+ return 0;
+}
+
+static int efi_pstore_write(enum pstore_type_id type,
+ enum kmsg_dump_reason reason, u64 *id,
+ unsigned int part, size_t size, struct pstore_info *psi)
+{
+ char name[DUMP_NAME_LEN];
+ char stub_name[DUMP_NAME_LEN];
+ efi_char16_t efi_name[DUMP_NAME_LEN];
+ efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
+ struct efivars *efivars = psi->data;
+ struct efivar_entry *entry, *found = NULL;
+ int i, ret = 0;
+
+ sprintf(stub_name, "dump-type%u-%u-", type, part);
+ sprintf(name, "%s%lu", stub_name, get_seconds());
+
+ spin_lock(&efivars->lock);
+
+ for (i = 0; i < DUMP_NAME_LEN; i++)
+ efi_name[i] = stub_name[i];
+
+ /*
+ * Clean up any entries with the same name
+ */
+
+ list_for_each_entry(entry, &efivars->list, list) {
+ get_var_data_locked(efivars, &entry->var);
+
+ if (efi_guidcmp(entry->var.VendorGuid, vendor))
+ continue;
+ if (utf16_strncmp(entry->var.VariableName, efi_name,
+ utf16_strlen(efi_name)))
+ continue;
+ /* Needs to be a prefix */
+ if (entry->var.VariableName[utf16_strlen(efi_name)] == 0)
+ continue;
+
+ /* found */
+ found = entry;
+ efivars->ops->set_variable(entry->var.VariableName,
+ &entry->var.VendorGuid,
+ PSTORE_EFI_ATTRIBUTES,
+ 0, NULL);
+ }
+
+ if (found)
+ list_del(&found->list);
+
+ for (i = 0; i < DUMP_NAME_LEN; i++)
+ efi_name[i] = name[i];
+
+ efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES,
+ size, psi->buf);
+
+ spin_unlock(&efivars->lock);
+
+ if (found)
+ efivar_unregister(found);
+
+ if (size)
+ ret = efivar_create_sysfs_entry(efivars,
+ utf16_strsize(efi_name,
+ DUMP_NAME_LEN * 2),
+ efi_name, &vendor);
+
+ *id = part;
+ return ret;
+};
+
+static int efi_pstore_erase(enum pstore_type_id type, u64 id,
+ struct pstore_info *psi)
+{
+ efi_pstore_write(type, 0, &id, (unsigned int)id, 0, psi);
+
+ return 0;
+}
+#else
+static int efi_pstore_open(struct pstore_info *psi)
+{
+ return 0;
+}
+
+static int efi_pstore_close(struct pstore_info *psi)
+{
+ return 0;
+}
+
+static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
+ struct timespec *timespec,
+ char **buf, struct pstore_info *psi)
+{
+ return -1;
+}
+
+static int efi_pstore_write(enum pstore_type_id type,
+ enum kmsg_dump_reason reason, u64 *id,
+ unsigned int part, size_t size, struct pstore_info *psi)
+{
+ return 0;
+}
+
+static int efi_pstore_erase(enum pstore_type_id type, u64 id,
+ struct pstore_info *psi)
+{
+ return 0;
+}
+#endif
+
+static struct pstore_info efi_pstore_info = {
+ .owner = THIS_MODULE,
+ .name = "efi",
+ .open = efi_pstore_open,
+ .close = efi_pstore_close,
+ .read = efi_pstore_read,
+ .write = efi_pstore_write,
+ .erase = efi_pstore_erase,
+};
+
+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 efi_variable *new_var = (struct efi_variable *)buf;
+ struct efivars *efivars = bin_attr->private;
+ struct efivar_entry *search_efivar, *n;
+ unsigned long strsize1, strsize2;
+ efi_status_t status = EFI_NOT_FOUND;
+ int found = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 ||
+ validate_var(new_var, new_var->Data, new_var->DataSize) == false) {
+ printk(KERN_ERR "efivars: Malformed variable content\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&efivars->lock);
+
+ /*
+ * Does this variable already exist?
+ */
+ list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
+ strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
+ strsize2 = utf16_strsize(new_var->VariableName, 1024);
+ if (strsize1 == strsize2 &&
+ !memcmp(&(search_efivar->var.VariableName),
+ new_var->VariableName, strsize1) &&
+ !efi_guidcmp(search_efivar->var.VendorGuid,
+ new_var->VendorGuid)) {
+ found = 1;
+ break;
+ }
+ }
+ if (found) {
+ spin_unlock(&efivars->lock);
+ return -EINVAL;
+ }
+
+ /* now *really* create the variable via EFI */
+ status = efivars->ops->set_variable(new_var->VariableName,
+ &new_var->VendorGuid,
+ new_var->Attributes,
+ new_var->DataSize,
+ new_var->Data);
+
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
+ status);
+ spin_unlock(&efivars->lock);
+ return -EIO;
+ }
+ spin_unlock(&efivars->lock);
+
+ /* Create the entry in sysfs. Locking is not required here */
+ status = efivar_create_sysfs_entry(efivars,
+ utf16_strsize(new_var->VariableName,
+ 1024),
+ new_var->VariableName,
+ &new_var->VendorGuid);
+ if (status) {
+ printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
+ }
+ return count;
+}
+
+static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t pos, size_t count)
+{
+ struct efi_variable *del_var = (struct efi_variable *)buf;
+ struct efivars *efivars = bin_attr->private;
+ struct efivar_entry *search_efivar, *n;
+ unsigned long strsize1, strsize2;
+ efi_status_t status = EFI_NOT_FOUND;
+ int found = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ spin_lock(&efivars->lock);
+
+ /*
+ * Does this variable already exist?
+ */
+ list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
+ strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024);
+ strsize2 = utf16_strsize(del_var->VariableName, 1024);
+ if (strsize1 == strsize2 &&
+ !memcmp(&(search_efivar->var.VariableName),
+ del_var->VariableName, strsize1) &&
+ !efi_guidcmp(search_efivar->var.VendorGuid,
+ del_var->VendorGuid)) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found) {
+ spin_unlock(&efivars->lock);
+ return -EINVAL;
+ }
+ /* force the Attributes/DataSize to 0 to ensure deletion */
+ del_var->Attributes = 0;
+ del_var->DataSize = 0;
+
+ status = efivars->ops->set_variable(del_var->VariableName,
+ &del_var->VendorGuid,
+ del_var->Attributes,
+ del_var->DataSize,
+ del_var->Data);
+
+ if (status != EFI_SUCCESS) {
+ printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
+ status);
+ spin_unlock(&efivars->lock);
+ return -EIO;
+ }
+ list_del(&search_efivar->list);
+ /* We need to release this lock before unregistering. */
+ spin_unlock(&efivars->lock);
+ efivar_unregister(search_efivar);
+
+ /* It's dead Jim.... */
+ return count;
+}
+
+/*
+ * Let's not leave out systab information that snuck into
+ * the efivars driver
+ */
+static ssize_t systab_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ char *str = buf;
+
+ if (!kobj || !buf)
+ return -EINVAL;
+
+ if (efi.mps != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "MPS=0x%lx\n", efi.mps);
+ if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
+ if (efi.acpi != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
+ if (efi.smbios != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
+ if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
+ if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
+ if (efi.uga != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "UGA=0x%lx\n", efi.uga);
+
+ return str - buf;
+}
+
+static struct kobj_attribute efi_attr_systab =
+ __ATTR(systab, 0400, systab_show, NULL);
+
+static struct attribute *efi_subsys_attrs[] = {
+ &efi_attr_systab.attr,
+ NULL, /* maybe more in the future? */
+};
+
+static struct attribute_group efi_subsys_attr_group = {
+ .attrs = efi_subsys_attrs,
+};
+
+static struct kobject *efi_kobj;
+
+/*
+ * efivar_create_sysfs_entry()
+ * Requires:
+ * variable_name_size = number of bytes required to hold
+ * variable_name (not counting the NULL
+ * character at the end.
+ * efivars->lock is not held on entry or exit.
+ * Returns 1 on failure, 0 on success
+ */
+static int
+efivar_create_sysfs_entry(struct efivars *efivars,
+ unsigned long variable_name_size,
+ efi_char16_t *variable_name,
+ efi_guid_t *vendor_guid)
+{
+ int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
+ char *short_name;
+ struct efivar_entry *new_efivar;
+
+ short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
+ new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
+
+ if (!short_name || !new_efivar) {
+ kfree(short_name);
+ kfree(new_efivar);
+ return 1;
+ }
+
+ new_efivar->efivars = efivars;
+ memcpy(new_efivar->var.VariableName, variable_name,
+ variable_name_size);
+ memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
+
+ /* Convert Unicode to normal chars (assume top bits are 0),
+ ala UTF-8 */
+ for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) {
+ short_name[i] = variable_name[i] & 0xFF;
+ }
+ /* This is ugly, but necessary to separate one vendor's
+ private variables from another's. */
+
+ *(short_name + strlen(short_name)) = '-';
+ efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
+
+ new_efivar->kobj.kset = efivars->kset;
+ i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
+ "%s", short_name);
+ if (i) {
+ kfree(short_name);
+ kfree(new_efivar);
+ return 1;
+ }
+
+ kobject_uevent(&new_efivar->kobj, KOBJ_ADD);
+ kfree(short_name);
+ short_name = NULL;
+
+ spin_lock(&efivars->lock);
+ list_add(&new_efivar->list, &efivars->list);
+ spin_unlock(&efivars->lock);
+
+ return 0;
+}
+
+static int
+create_efivars_bin_attributes(struct efivars *efivars)
+{
+ struct bin_attribute *attr;
+ int error;
+
+ /* new_var */
+ attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+ if (!attr)
+ return -ENOMEM;
+
+ attr->attr.name = "new_var";
+ attr->attr.mode = 0200;
+ attr->write = efivar_create;
+ attr->private = efivars;
+ efivars->new_var = attr;
+
+ /* del_var */
+ attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+ if (!attr) {
+ error = -ENOMEM;
+ goto out_free;
+ }
+ attr->attr.name = "del_var";
+ attr->attr.mode = 0200;
+ attr->write = efivar_delete;
+ attr->private = efivars;
+ efivars->del_var = attr;
+
+ sysfs_bin_attr_init(efivars->new_var);
+ sysfs_bin_attr_init(efivars->del_var);
+
+ /* Register */
+ error = sysfs_create_bin_file(&efivars->kset->kobj,
+ efivars->new_var);
+ if (error) {
+ printk(KERN_ERR "efivars: unable to create new_var sysfs file"
+ " due to error %d\n", error);
+ goto out_free;
+ }
+ error = sysfs_create_bin_file(&efivars->kset->kobj,
+ efivars->del_var);
+ if (error) {
+ printk(KERN_ERR "efivars: unable to create del_var sysfs file"
+ " due to error %d\n", error);
+ sysfs_remove_bin_file(&efivars->kset->kobj,
+ efivars->new_var);
+ goto out_free;
+ }
+
+ return 0;
+out_free:
+ kfree(efivars->del_var);
+ efivars->del_var = NULL;
+ kfree(efivars->new_var);
+ efivars->new_var = NULL;
+ return error;
+}
+
+void unregister_efivars(struct efivars *efivars)
+{
+ struct efivar_entry *entry, *n;
+
+ list_for_each_entry_safe(entry, n, &efivars->list, list) {
+ spin_lock(&efivars->lock);
+ list_del(&entry->list);
+ spin_unlock(&efivars->lock);
+ efivar_unregister(entry);
+ }
+ if (efivars->new_var)
+ sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
+ if (efivars->del_var)
+ sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
+ kfree(efivars->new_var);
+ kfree(efivars->del_var);
+ kset_unregister(efivars->kset);
+}
+EXPORT_SYMBOL_GPL(unregister_efivars);
+
+int register_efivars(struct efivars *efivars,
+ const struct efivar_operations *ops,
+ struct kobject *parent_kobj)
+{
+ efi_status_t status = EFI_NOT_FOUND;
+ efi_guid_t vendor_guid;
+ efi_char16_t *variable_name;
+ unsigned long variable_name_size = 1024;
+ int error = 0;
+
+ variable_name = kzalloc(variable_name_size, GFP_KERNEL);
+ if (!variable_name) {
+ printk(KERN_ERR "efivars: Memory allocation failed.\n");
+ return -ENOMEM;
+ }
+
+ spin_lock_init(&efivars->lock);
+ INIT_LIST_HEAD(&efivars->list);
+ efivars->ops = ops;
+
+ efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
+ if (!efivars->kset) {
+ printk(KERN_ERR "efivars: Subsystem registration failed.\n");
+ error = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * Per EFI spec, the maximum storage allocated for both
+ * the variable name and variable data is 1024 bytes.
+ */
+
+ do {
+ variable_name_size = 1024;
+
+ status = ops->get_next_variable(&variable_name_size,
+ variable_name,
+ &vendor_guid);
+ switch (status) {
+ case EFI_SUCCESS:
+ efivar_create_sysfs_entry(efivars,
+ variable_name_size,
+ variable_name,
+ &vendor_guid);
+ break;
+ case EFI_NOT_FOUND:
+ break;
+ default:
+ printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
+ status);
+ status = EFI_NOT_FOUND;
+ break;
+ }
+ } while (status != EFI_NOT_FOUND);
+
+ error = create_efivars_bin_attributes(efivars);
+ if (error)
+ unregister_efivars(efivars);
+
+ efivars->efi_pstore_info = efi_pstore_info;
+
+ efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
+ if (efivars->efi_pstore_info.buf) {
+ efivars->efi_pstore_info.bufsize = 1024;
+ efivars->efi_pstore_info.data = efivars;
+ spin_lock_init(&efivars->efi_pstore_info.buf_lock);
+ pstore_register(&efivars->efi_pstore_info);
+ }
+
+out:
+ kfree(variable_name);
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(register_efivars);
+
+static struct efivars __efivars;
+static struct efivar_operations ops;
+
+/*
+ * For now we register the efi subsystem with the firmware subsystem
+ * and the vars subsystem with the efi subsystem. In the future, it
+ * might make sense to split off the efi subsystem into its own
+ * driver, but for now only efivars will register with it, so just
+ * include it here.
+ */
+
+static int __init
+efivars_init(void)
+{
+ int error = 0;
+
+ printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
+ EFIVARS_DATE);
+
+ if (!efi_enabled)
+ return 0;
+
+ /* For now we'll register the efi directory at /sys/firmware/efi */
+ efi_kobj = kobject_create_and_add("efi", firmware_kobj);
+ if (!efi_kobj) {
+ printk(KERN_ERR "efivars: Firmware registration failed.\n");
+ return -ENOMEM;
+ }
+
+ ops.get_variable = efi.get_variable;
+ ops.set_variable = efi.set_variable;
+ ops.get_next_variable = efi.get_next_variable;
+ error = register_efivars(&__efivars, &ops, efi_kobj);
+ if (error)
+ goto err_put;
+
+ /* Don't forget the systab entry */
+ error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
+ if (error) {
+ printk(KERN_ERR
+ "efivars: Sysfs attribute export failed with error %d.\n",
+ error);
+ goto err_unregister;
+ }
+
+ return 0;
+
+err_unregister:
+ unregister_efivars(&__efivars);
+err_put:
+ kobject_put(efi_kobj);
+ return error;
+}
+
+static void __exit
+efivars_exit(void)
+{
+ if (efi_enabled) {
+ unregister_efivars(&__efivars);
+ kobject_put(efi_kobj);
+ }
+}
+
+module_init(efivars_init);
+module_exit(efivars_exit);
+
generated by cgit (git 2.34.1) at 2024-12-20 09:05:13 +0000