2 * Originally from efivars.c
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/capability.h>
23 #include <linux/types.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/string.h>
29 #include <linux/smp.h>
30 #include <linux/efi.h>
31 #include <linux/sysfs.h>
32 #include <linux/device.h>
33 #include <linux/slab.h>
34 #include <linux/ctype.h>
35 #include <linux/ucs2_string.h>
37 /* Private pointer to registered efivars */
38 static struct efivars *__efivars;
41 * efivars_lock protects three things:
42 * 1) efivarfs_list and efivars_sysfs_list
44 * 3) (un)registration of __efivars
46 static DEFINE_SEMAPHORE(efivars_lock);
48 static bool efivar_wq_enabled = true;
49 DECLARE_WORK(efivar_work, NULL);
50 EXPORT_SYMBOL_GPL(efivar_work);
53 validate_device_path(efi_char16_t *var_name, int match, u8 *buffer,
56 struct efi_generic_dev_path *node;
59 node = (struct efi_generic_dev_path *)buffer;
61 if (len < sizeof(*node))
64 while (offset <= len - sizeof(*node) &&
65 node->length >= sizeof(*node) &&
66 node->length <= len - offset) {
67 offset += node->length;
69 if ((node->type == EFI_DEV_END_PATH ||
70 node->type == EFI_DEV_END_PATH2) &&
71 node->sub_type == EFI_DEV_END_ENTIRE)
74 node = (struct efi_generic_dev_path *)(buffer + offset);
78 * If we're here then either node->length pointed past the end
79 * of the buffer or we reached the end of the buffer without
80 * finding a device path end node.
86 validate_boot_order(efi_char16_t *var_name, int match, u8 *buffer,
89 /* An array of 16-bit integers */
97 validate_load_option(efi_char16_t *var_name, int match, u8 *buffer,
101 int i, desclength = 0, namelen;
103 namelen = ucs2_strnlen(var_name, EFI_VAR_NAME_LEN);
105 /* Either "Boot" or "Driver" followed by four digits of hex */
106 for (i = match; i < match+4; i++) {
107 if (var_name[i] > 127 ||
108 hex_to_bin(var_name[i] & 0xff) < 0)
112 /* Reject it if there's 4 digits of hex and then further content */
113 if (namelen > match + 4)
116 /* A valid entry must be at least 8 bytes */
120 filepathlength = buffer[4] | buffer[5] << 8;
123 * There's no stored length for the description, so it has to be
126 desclength = ucs2_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
128 /* Each boot entry must have a descriptor */
133 * If the sum of the length of the description, the claimed filepath
134 * length and the original header are greater than the length of the
135 * variable, it's malformed
137 if ((desclength + filepathlength + 6) > len)
141 * And, finally, check the filepath
143 return validate_device_path(var_name, match, buffer + desclength + 6,
148 validate_uint16(efi_char16_t *var_name, int match, u8 *buffer,
151 /* A single 16-bit integer */
159 validate_ascii_string(efi_char16_t *var_name, int match, u8 *buffer,
164 for (i = 0; i < len; i++) {
175 struct variable_validate {
178 bool (*validate)(efi_char16_t *var_name, int match, u8 *data,
183 * This is the list of variables we need to validate, as well as the
184 * whitelist for what we think is safe not to default to immutable.
186 * If it has a validate() method that's not NULL, it'll go into the
187 * validation routine. If not, it is assumed valid, but still used for
190 * Note that it's sorted by {vendor,name}, but globbed names must come after
191 * any other name with the same prefix.
193 static const struct variable_validate variable_validate[] = {
194 { EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 },
195 { EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order },
196 { EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option },
197 { EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order },
198 { EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option },
199 { EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path },
200 { EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path },
201 { EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path },
202 { EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path },
203 { EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path },
204 { EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path },
205 { EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string },
206 { EFI_GLOBAL_VARIABLE_GUID, "OsIndications", NULL },
207 { EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string },
208 { EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 },
209 { LINUX_EFI_CRASH_GUID, "*", NULL },
210 { NULL_GUID, "", NULL },
214 * Check if @var_name matches the pattern given in @match_name.
216 * @var_name: an array of @len non-NUL characters.
217 * @match_name: a NUL-terminated pattern string, optionally ending in "*". A
218 * final "*" character matches any trailing characters @var_name,
219 * including the case when there are none left in @var_name.
220 * @match: on output, the number of non-wildcard characters in @match_name
221 * that @var_name matches, regardless of the return value.
222 * @return: whether @var_name fully matches @match_name.
225 variable_matches(const char *var_name, size_t len, const char *match_name,
228 for (*match = 0; ; (*match)++) {
229 char c = match_name[*match];
233 /* Wildcard in @match_name means we've matched. */
237 /* @match_name has ended. Has @var_name too? */
238 return (*match == len);
242 * We've reached a non-wildcard char in @match_name.
243 * Continue only if there's an identical character in
246 if (*match < len && c == var_name[*match])
254 efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data,
255 unsigned long data_size)
258 unsigned long utf8_size;
261 utf8_size = ucs2_utf8size(var_name);
262 utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL);
266 ucs2_as_utf8(utf8_name, var_name, utf8_size);
267 utf8_name[utf8_size] = '\0';
269 for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
270 const char *name = variable_validate[i].name;
273 if (efi_guidcmp(vendor, variable_validate[i].vendor))
276 if (variable_matches(utf8_name, utf8_size+1, name, &match)) {
277 if (variable_validate[i].validate == NULL)
280 return variable_validate[i].validate(var_name, match,
287 EXPORT_SYMBOL_GPL(efivar_validate);
290 efivar_variable_is_removable(efi_guid_t vendor, const char *var_name,
298 * Check if our variable is in the validated variables list
300 for (i = 0; variable_validate[i].name[0] != '\0'; i++) {
301 if (efi_guidcmp(variable_validate[i].vendor, vendor))
304 if (variable_matches(var_name, len,
305 variable_validate[i].name, &match)) {
312 * If it's in our list, it is removable.
316 EXPORT_SYMBOL_GPL(efivar_variable_is_removable);
319 check_var_size(u32 attributes, unsigned long size)
321 const struct efivar_operations *fops;
324 return EFI_UNSUPPORTED;
326 fops = __efivars->ops;
328 if (!fops->query_variable_store)
329 return EFI_UNSUPPORTED;
331 return fops->query_variable_store(attributes, size, false);
335 check_var_size_nonblocking(u32 attributes, unsigned long size)
337 const struct efivar_operations *fops;
340 return EFI_UNSUPPORTED;
342 fops = __efivars->ops;
344 if (!fops->query_variable_store)
345 return EFI_UNSUPPORTED;
347 return fops->query_variable_store(attributes, size, true);
350 static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
351 struct list_head *head)
353 struct efivar_entry *entry, *n;
354 unsigned long strsize1, strsize2;
357 strsize1 = ucs2_strsize(variable_name, 1024);
358 list_for_each_entry_safe(entry, n, head, list) {
359 strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
360 if (strsize1 == strsize2 &&
361 !memcmp(variable_name, &(entry->var.VariableName),
363 !efi_guidcmp(entry->var.VendorGuid,
373 * Returns the size of variable_name, in bytes, including the
374 * terminating NULL character, or variable_name_size if no NULL
375 * character is found among the first variable_name_size bytes.
377 static unsigned long var_name_strnsize(efi_char16_t *variable_name,
378 unsigned long variable_name_size)
384 * The variable name is, by definition, a NULL-terminated
385 * string, so make absolutely sure that variable_name_size is
386 * the value we expect it to be. If not, return the real size.
388 for (len = 2; len <= variable_name_size; len += sizeof(c)) {
389 c = variable_name[(len / sizeof(c)) - 1];
394 return min(len, variable_name_size);
398 * Print a warning when duplicate EFI variables are encountered and
399 * disable the sysfs workqueue since the firmware is buggy.
401 static void dup_variable_bug(efi_char16_t *str16, efi_guid_t *vendor_guid,
404 size_t i, len8 = len16 / sizeof(efi_char16_t);
408 * Disable the workqueue since the algorithm it uses for
409 * detecting new variables won't work with this buggy
410 * implementation of GetNextVariableName().
412 efivar_wq_enabled = false;
414 str8 = kzalloc(len8, GFP_KERNEL);
418 for (i = 0; i < len8; i++)
421 printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
427 * efivar_init - build the initial list of EFI variables
428 * @func: callback function to invoke for every variable
429 * @data: function-specific data to pass to @func
430 * @atomic: do we need to execute the @func-loop atomically?
431 * @duplicates: error if we encounter duplicates on @head?
432 * @head: initialised head of variable list
434 * Get every EFI variable from the firmware and invoke @func. @func
435 * should call efivar_entry_add() to build the list of variables.
437 * Returns 0 on success, or a kernel error code on failure.
439 int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
440 void *data, bool duplicates, struct list_head *head)
442 const struct efivar_operations *ops;
443 unsigned long variable_name_size = 1024;
444 efi_char16_t *variable_name;
446 efi_guid_t vendor_guid;
452 ops = __efivars->ops;
454 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
455 if (!variable_name) {
456 printk(KERN_ERR "efivars: Memory allocation failed.\n");
460 if (down_interruptible(&efivars_lock)) {
466 * Per EFI spec, the maximum storage allocated for both
467 * the variable name and variable data is 1024 bytes.
471 variable_name_size = 1024;
473 status = ops->get_next_variable(&variable_name_size,
481 variable_name_size = var_name_strnsize(variable_name,
485 * Some firmware implementations return the
486 * same variable name on multiple calls to
487 * get_next_variable(). Terminate the loop
488 * immediately as there is no guarantee that
489 * we'll ever see a different variable name,
490 * and may end up looping here forever.
493 variable_is_present(variable_name, &vendor_guid,
495 dup_variable_bug(variable_name, &vendor_guid,
497 status = EFI_NOT_FOUND;
499 err = func(variable_name, vendor_guid,
500 variable_name_size, data);
502 status = EFI_NOT_FOUND;
506 if (down_interruptible(&efivars_lock)) {
516 printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
518 status = EFI_NOT_FOUND;
522 } while (status != EFI_NOT_FOUND);
526 kfree(variable_name);
530 EXPORT_SYMBOL_GPL(efivar_init);
533 * efivar_entry_add - add entry to variable list
534 * @entry: entry to add to list
537 * Returns 0 on success, or a kernel error code on failure.
539 int efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
541 if (down_interruptible(&efivars_lock))
543 list_add(&entry->list, head);
548 EXPORT_SYMBOL_GPL(efivar_entry_add);
551 * efivar_entry_remove - remove entry from variable list
552 * @entry: entry to remove from list
554 * Returns 0 on success, or a kernel error code on failure.
556 int efivar_entry_remove(struct efivar_entry *entry)
558 if (down_interruptible(&efivars_lock))
560 list_del(&entry->list);
565 EXPORT_SYMBOL_GPL(efivar_entry_remove);
568 * efivar_entry_list_del_unlock - remove entry from variable list
569 * @entry: entry to remove
571 * Remove @entry from the variable list and release the list lock.
573 * NOTE: slightly weird locking semantics here - we expect to be
574 * called with the efivars lock already held, and we release it before
575 * returning. This is because this function is usually called after
576 * set_variable() while the lock is still held.
578 static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
580 list_del(&entry->list);
585 * __efivar_entry_delete - delete an EFI variable
586 * @entry: entry containing EFI variable to delete
588 * Delete the variable from the firmware but leave @entry on the
591 * This function differs from efivar_entry_delete() because it does
592 * not remove @entry from the variable list. Also, it is safe to be
593 * called from within a efivar_entry_iter_begin() and
594 * efivar_entry_iter_end() region, unlike efivar_entry_delete().
596 * Returns 0 on success, or a converted EFI status code if
597 * set_variable() fails.
599 int __efivar_entry_delete(struct efivar_entry *entry)
606 status = __efivars->ops->set_variable(entry->var.VariableName,
607 &entry->var.VendorGuid,
610 return efi_status_to_err(status);
612 EXPORT_SYMBOL_GPL(__efivar_entry_delete);
615 * efivar_entry_delete - delete variable and remove entry from list
616 * @entry: entry containing variable to delete
618 * Delete the variable from the firmware and remove @entry from the
619 * variable list. It is the caller's responsibility to free @entry
622 * Returns 0 on success, -EINTR if we can't grab the semaphore,
623 * converted EFI status code if set_variable() fails.
625 int efivar_entry_delete(struct efivar_entry *entry)
627 const struct efivar_operations *ops;
630 if (down_interruptible(&efivars_lock))
637 ops = __efivars->ops;
638 status = ops->set_variable(entry->var.VariableName,
639 &entry->var.VendorGuid,
641 if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
643 return efi_status_to_err(status);
646 efivar_entry_list_del_unlock(entry);
649 EXPORT_SYMBOL_GPL(efivar_entry_delete);
652 * efivar_entry_set - call set_variable()
653 * @entry: entry containing the EFI variable to write
654 * @attributes: variable attributes
655 * @size: size of @data buffer
656 * @data: buffer containing variable data
657 * @head: head of variable list
659 * Calls set_variable() for an EFI variable. If creating a new EFI
660 * variable, this function is usually followed by efivar_entry_add().
662 * Before writing the variable, the remaining EFI variable storage
663 * space is checked to ensure there is enough room available.
665 * If @head is not NULL a lookup is performed to determine whether
666 * the entry is already on the list.
668 * Returns 0 on success, -EINTR if we can't grab the semaphore,
669 * -EEXIST if a lookup is performed and the entry already exists on
670 * the list, or a converted EFI status code if set_variable() fails.
672 int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
673 unsigned long size, void *data, struct list_head *head)
675 const struct efivar_operations *ops;
677 efi_char16_t *name = entry->var.VariableName;
678 efi_guid_t vendor = entry->var.VendorGuid;
680 if (down_interruptible(&efivars_lock))
687 ops = __efivars->ops;
688 if (head && efivar_entry_find(name, vendor, head, false)) {
693 status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
694 if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
695 status = ops->set_variable(name, &vendor,
696 attributes, size, data);
700 return efi_status_to_err(status);
703 EXPORT_SYMBOL_GPL(efivar_entry_set);
706 * efivar_entry_set_nonblocking - call set_variable_nonblocking()
708 * This function is guaranteed to not block and is suitable for calling
709 * from crash/panic handlers.
711 * Crucially, this function will not block if it cannot acquire
712 * efivars_lock. Instead, it returns -EBUSY.
715 efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
716 u32 attributes, unsigned long size, void *data)
718 const struct efivar_operations *ops;
721 if (down_trylock(&efivars_lock))
729 status = check_var_size_nonblocking(attributes,
730 size + ucs2_strsize(name, 1024));
731 if (status != EFI_SUCCESS) {
736 ops = __efivars->ops;
737 status = ops->set_variable_nonblocking(name, &vendor, attributes,
741 return efi_status_to_err(status);
745 * efivar_entry_set_safe - call set_variable() if enough space in firmware
746 * @name: buffer containing the variable name
747 * @vendor: variable vendor guid
748 * @attributes: variable attributes
749 * @block: can we block in this context?
750 * @size: size of @data buffer
751 * @data: buffer containing variable data
753 * Ensures there is enough free storage in the firmware for this variable, and
754 * if so, calls set_variable(). If creating a new EFI variable, this function
755 * is usually followed by efivar_entry_add().
757 * Returns 0 on success, -ENOSPC if the firmware does not have enough
758 * space for set_variable() to succeed, or a converted EFI status code
759 * if set_variable() fails.
761 int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
762 bool block, unsigned long size, void *data)
764 const struct efivar_operations *ops;
766 unsigned long varsize;
771 ops = __efivars->ops;
772 if (!ops->query_variable_store)
776 * If the EFI variable backend provides a non-blocking
777 * ->set_variable() operation and we're in a context where we
778 * cannot block, then we need to use it to avoid live-locks,
779 * since the implication is that the regular ->set_variable()
782 * If no ->set_variable_nonblocking() is provided then
783 * ->set_variable() is assumed to be non-blocking.
785 if (!block && ops->set_variable_nonblocking)
786 return efivar_entry_set_nonblocking(name, vendor, attributes,
789 varsize = size + ucs2_strsize(name, 1024);
791 if (down_trylock(&efivars_lock))
793 status = check_var_size_nonblocking(attributes, varsize);
795 if (down_interruptible(&efivars_lock))
797 status = check_var_size(attributes, varsize);
800 if (status != EFI_SUCCESS) {
805 status = ops->set_variable(name, &vendor, attributes, size, data);
809 return efi_status_to_err(status);
811 EXPORT_SYMBOL_GPL(efivar_entry_set_safe);
814 * efivar_entry_find - search for an entry
815 * @name: the EFI variable name
816 * @guid: the EFI variable vendor's guid
817 * @head: head of the variable list
818 * @remove: should we remove the entry from the list?
820 * Search for an entry on the variable list that has the EFI variable
821 * name @name and vendor guid @guid. If an entry is found on the list
822 * and @remove is true, the entry is removed from the list.
824 * The caller MUST call efivar_entry_iter_begin() and
825 * efivar_entry_iter_end() before and after the invocation of this
826 * function, respectively.
828 * Returns the entry if found on the list, %NULL otherwise.
830 struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
831 struct list_head *head, bool remove)
833 struct efivar_entry *entry, *n;
834 int strsize1, strsize2;
837 list_for_each_entry_safe(entry, n, head, list) {
838 strsize1 = ucs2_strsize(name, 1024);
839 strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
840 if (strsize1 == strsize2 &&
841 !memcmp(name, &(entry->var.VariableName), strsize1) &&
842 !efi_guidcmp(guid, entry->var.VendorGuid)) {
852 if (entry->scanning) {
854 * The entry will be deleted
855 * after scanning is completed.
857 entry->deleting = true;
859 list_del(&entry->list);
864 EXPORT_SYMBOL_GPL(efivar_entry_find);
867 * efivar_entry_size - obtain the size of a variable
868 * @entry: entry for this variable
869 * @size: location to store the variable's size
871 int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
873 const struct efivar_operations *ops;
878 if (down_interruptible(&efivars_lock))
884 ops = __efivars->ops;
885 status = ops->get_variable(entry->var.VariableName,
886 &entry->var.VendorGuid, NULL, size, NULL);
889 if (status != EFI_BUFFER_TOO_SMALL)
890 return efi_status_to_err(status);
894 EXPORT_SYMBOL_GPL(efivar_entry_size);
897 * __efivar_entry_get - call get_variable()
898 * @entry: read data for this variable
899 * @attributes: variable attributes
900 * @size: size of @data buffer
901 * @data: buffer to store variable data
903 * The caller MUST call efivar_entry_iter_begin() and
904 * efivar_entry_iter_end() before and after the invocation of this
905 * function, respectively.
907 int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
908 unsigned long *size, void *data)
915 status = __efivars->ops->get_variable(entry->var.VariableName,
916 &entry->var.VendorGuid,
917 attributes, size, data);
919 return efi_status_to_err(status);
921 EXPORT_SYMBOL_GPL(__efivar_entry_get);
924 * efivar_entry_get - call get_variable()
925 * @entry: read data for this variable
926 * @attributes: variable attributes
927 * @size: size of @data buffer
928 * @data: buffer to store variable data
930 int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
931 unsigned long *size, void *data)
935 if (down_interruptible(&efivars_lock))
943 status = __efivars->ops->get_variable(entry->var.VariableName,
944 &entry->var.VendorGuid,
945 attributes, size, data);
948 return efi_status_to_err(status);
950 EXPORT_SYMBOL_GPL(efivar_entry_get);
953 * efivar_entry_set_get_size - call set_variable() and get new size (atomic)
954 * @entry: entry containing variable to set and get
955 * @attributes: attributes of variable to be written
956 * @size: size of data buffer
957 * @data: buffer containing data to write
958 * @set: did the set_variable() call succeed?
960 * This is a pretty special (complex) function. See efivarfs_file_write().
962 * Atomically call set_variable() for @entry and if the call is
963 * successful, return the new size of the variable from get_variable()
964 * in @size. The success of set_variable() is indicated by @set.
966 * Returns 0 on success, -EINVAL if the variable data is invalid,
967 * -ENOSPC if the firmware does not have enough available space, or a
968 * converted EFI status code if either of set_variable() or
969 * get_variable() fail.
971 * If the EFI variable does not exist when calling set_variable()
972 * (EFI_NOT_FOUND), @entry is removed from the variable list.
974 int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
975 unsigned long *size, void *data, bool *set)
977 const struct efivar_operations *ops;
978 efi_char16_t *name = entry->var.VariableName;
979 efi_guid_t *vendor = &entry->var.VendorGuid;
985 if (efivar_validate(*vendor, name, data, *size) == false)
989 * The lock here protects the get_variable call, the conditional
990 * set_variable call, and removal of the variable from the efivars
991 * list (in the case of an authenticated delete).
993 if (down_interruptible(&efivars_lock))
1002 * Ensure that the available space hasn't shrunk below the safe level
1004 status = check_var_size(attributes, *size + ucs2_strsize(name, 1024));
1005 if (status != EFI_SUCCESS) {
1006 if (status != EFI_UNSUPPORTED) {
1007 err = efi_status_to_err(status);
1011 if (*size > 65536) {
1017 ops = __efivars->ops;
1019 status = ops->set_variable(name, vendor, attributes, *size, data);
1020 if (status != EFI_SUCCESS) {
1021 err = efi_status_to_err(status);
1028 * Writing to the variable may have caused a change in size (which
1029 * could either be an append or an overwrite), or the variable to be
1030 * deleted. Perform a GetVariable() so we can tell what actually
1034 status = ops->get_variable(entry->var.VariableName,
1035 &entry->var.VendorGuid,
1038 if (status == EFI_NOT_FOUND)
1039 efivar_entry_list_del_unlock(entry);
1043 if (status && status != EFI_BUFFER_TOO_SMALL)
1044 return efi_status_to_err(status);
1053 EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
1056 * efivar_entry_iter_begin - begin iterating the variable list
1058 * Lock the variable list to prevent entry insertion and removal until
1059 * efivar_entry_iter_end() is called. This function is usually used in
1060 * conjunction with __efivar_entry_iter() or efivar_entry_iter().
1062 int efivar_entry_iter_begin(void)
1064 return down_interruptible(&efivars_lock);
1066 EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
1069 * efivar_entry_iter_end - finish iterating the variable list
1071 * Unlock the variable list and allow modifications to the list again.
1073 void efivar_entry_iter_end(void)
1077 EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
1080 * __efivar_entry_iter - iterate over variable list
1081 * @func: callback function
1082 * @head: head of the variable list
1083 * @data: function-specific data to pass to callback
1084 * @prev: entry to begin iterating from
1086 * Iterate over the list of EFI variables and call @func with every
1087 * entry on the list. It is safe for @func to remove entries in the
1088 * list via efivar_entry_delete().
1090 * You MUST call efivar_enter_iter_begin() before this function, and
1091 * efivar_entry_iter_end() afterwards.
1093 * It is possible to begin iteration from an arbitrary entry within
1094 * the list by passing @prev. @prev is updated on return to point to
1095 * the last entry passed to @func. To begin iterating from the
1096 * beginning of the list @prev must be %NULL.
1098 * The restrictions for @func are the same as documented for
1099 * efivar_entry_iter().
1101 int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
1102 struct list_head *head, void *data,
1103 struct efivar_entry **prev)
1105 struct efivar_entry *entry, *n;
1108 if (!prev || !*prev) {
1109 list_for_each_entry_safe(entry, n, head, list) {
1110 err = func(entry, data);
1122 list_for_each_entry_safe_continue((*prev), n, head, list) {
1123 err = func(*prev, data);
1130 EXPORT_SYMBOL_GPL(__efivar_entry_iter);
1133 * efivar_entry_iter - iterate over variable list
1134 * @func: callback function
1135 * @head: head of variable list
1136 * @data: function-specific data to pass to callback
1138 * Iterate over the list of EFI variables and call @func with every
1139 * entry on the list. It is safe for @func to remove entries in the
1140 * list via efivar_entry_delete() while iterating.
1142 * Some notes for the callback function:
1143 * - a non-zero return value indicates an error and terminates the loop
1144 * - @func is called from atomic context
1146 int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
1147 struct list_head *head, void *data)
1151 err = efivar_entry_iter_begin();
1154 err = __efivar_entry_iter(func, head, data, NULL);
1155 efivar_entry_iter_end();
1159 EXPORT_SYMBOL_GPL(efivar_entry_iter);
1162 * efivars_kobject - get the kobject for the registered efivars
1164 * If efivars_register() has not been called we return NULL,
1165 * otherwise return the kobject used at registration time.
1167 struct kobject *efivars_kobject(void)
1172 return __efivars->kobject;
1174 EXPORT_SYMBOL_GPL(efivars_kobject);
1177 * efivar_run_worker - schedule the efivar worker thread
1179 void efivar_run_worker(void)
1181 if (efivar_wq_enabled)
1182 schedule_work(&efivar_work);
1184 EXPORT_SYMBOL_GPL(efivar_run_worker);
1187 * efivars_register - register an efivars
1188 * @efivars: efivars to register
1189 * @ops: efivars operations
1190 * @kobject: @efivars-specific kobject
1192 * Only a single efivars can be registered at any time.
1194 int efivars_register(struct efivars *efivars,
1195 const struct efivar_operations *ops,
1196 struct kobject *kobject)
1198 if (down_interruptible(&efivars_lock))
1202 efivars->kobject = kobject;
1204 __efivars = efivars;
1206 pr_info("Registered efivars operations\n");
1212 EXPORT_SYMBOL_GPL(efivars_register);
1215 * efivars_unregister - unregister an efivars
1216 * @efivars: efivars to unregister
1218 * The caller must have already removed every entry from the list,
1219 * failure to do so is an error.
1221 int efivars_unregister(struct efivars *efivars)
1225 if (down_interruptible(&efivars_lock))
1229 printk(KERN_ERR "efivars not registered\n");
1234 if (__efivars != efivars) {
1239 pr_info("Unregistered efivars operations\n");
1247 EXPORT_SYMBOL_GPL(efivars_unregister);