Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
a9499fa7 | 2 | * Originally from efivars.c |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com> | |
5 | * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com> | |
6 | * | |
1da177e4 LT |
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. | |
11 | * | |
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. | |
16 | * | |
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 | |
1da177e4 LT |
20 | */ |
21 | ||
c59ede7b | 22 | #include <linux/capability.h> |
1da177e4 LT |
23 | #include <linux/types.h> |
24 | #include <linux/errno.h> | |
25 | #include <linux/init.h> | |
1da177e4 LT |
26 | #include <linux/mm.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> | |
1da177e4 | 32 | #include <linux/device.h> |
5a0e3ad6 | 33 | #include <linux/slab.h> |
47f531e8 | 34 | #include <linux/ctype.h> |
a614e192 | 35 | #include <linux/ucs2_string.h> |
1da177e4 | 36 | |
4423d779 MF |
37 | /* Private pointer to registered efivars */ |
38 | static struct efivars *__efivars; | |
5d9db883 | 39 | |
e971318b | 40 | static bool efivar_wq_enabled = true; |
a9499fa7 TG |
41 | DECLARE_WORK(efivar_work, NULL); |
42 | EXPORT_SYMBOL_GPL(efivar_work); | |
a93bc0c6 | 43 | |
fec6c20b | 44 | static bool |
a5d92ad3 | 45 | validate_device_path(efi_char16_t *var_name, int match, u8 *buffer, |
54b3a4d3 | 46 | unsigned long len) |
fec6c20b MG |
47 | { |
48 | struct efi_generic_dev_path *node; | |
49 | int offset = 0; | |
50 | ||
51 | node = (struct efi_generic_dev_path *)buffer; | |
52 | ||
54b3a4d3 MG |
53 | if (len < sizeof(*node)) |
54 | return false; | |
fec6c20b | 55 | |
54b3a4d3 MG |
56 | while (offset <= len - sizeof(*node) && |
57 | node->length >= sizeof(*node) && | |
58 | node->length <= len - offset) { | |
59 | offset += node->length; | |
fec6c20b MG |
60 | |
61 | if ((node->type == EFI_DEV_END_PATH || | |
62 | node->type == EFI_DEV_END_PATH2) && | |
63 | node->sub_type == EFI_DEV_END_ENTIRE) | |
64 | return true; | |
65 | ||
66 | node = (struct efi_generic_dev_path *)(buffer + offset); | |
67 | } | |
68 | ||
69 | /* | |
70 | * If we're here then either node->length pointed past the end | |
71 | * of the buffer or we reached the end of the buffer without | |
72 | * finding a device path end node. | |
73 | */ | |
74 | return false; | |
75 | } | |
76 | ||
77 | static bool | |
a5d92ad3 | 78 | validate_boot_order(efi_char16_t *var_name, int match, u8 *buffer, |
54b3a4d3 | 79 | unsigned long len) |
fec6c20b MG |
80 | { |
81 | /* An array of 16-bit integers */ | |
82 | if ((len % 2) != 0) | |
83 | return false; | |
84 | ||
85 | return true; | |
86 | } | |
87 | ||
88 | static bool | |
a5d92ad3 | 89 | validate_load_option(efi_char16_t *var_name, int match, u8 *buffer, |
54b3a4d3 | 90 | unsigned long len) |
fec6c20b MG |
91 | { |
92 | u16 filepathlength; | |
54b3a4d3 MG |
93 | int i, desclength = 0, namelen; |
94 | ||
a5d92ad3 | 95 | namelen = ucs2_strnlen(var_name, EFI_VAR_NAME_LEN); |
fec6c20b MG |
96 | |
97 | /* Either "Boot" or "Driver" followed by four digits of hex */ | |
98 | for (i = match; i < match+4; i++) { | |
a5d92ad3 MF |
99 | if (var_name[i] > 127 || |
100 | hex_to_bin(var_name[i] & 0xff) < 0) | |
fec6c20b MG |
101 | return true; |
102 | } | |
103 | ||
54b3a4d3 MG |
104 | /* Reject it if there's 4 digits of hex and then further content */ |
105 | if (namelen > match + 4) | |
106 | return false; | |
107 | ||
108 | /* A valid entry must be at least 8 bytes */ | |
109 | if (len < 8) | |
fec6c20b MG |
110 | return false; |
111 | ||
112 | filepathlength = buffer[4] | buffer[5] << 8; | |
113 | ||
114 | /* | |
115 | * There's no stored length for the description, so it has to be | |
116 | * found by hand | |
117 | */ | |
a614e192 | 118 | desclength = ucs2_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2; |
fec6c20b MG |
119 | |
120 | /* Each boot entry must have a descriptor */ | |
121 | if (!desclength) | |
122 | return false; | |
123 | ||
124 | /* | |
125 | * If the sum of the length of the description, the claimed filepath | |
126 | * length and the original header are greater than the length of the | |
127 | * variable, it's malformed | |
128 | */ | |
129 | if ((desclength + filepathlength + 6) > len) | |
130 | return false; | |
131 | ||
132 | /* | |
133 | * And, finally, check the filepath | |
134 | */ | |
a5d92ad3 | 135 | return validate_device_path(var_name, match, buffer + desclength + 6, |
fec6c20b MG |
136 | filepathlength); |
137 | } | |
138 | ||
139 | static bool | |
a5d92ad3 | 140 | validate_uint16(efi_char16_t *var_name, int match, u8 *buffer, |
54b3a4d3 | 141 | unsigned long len) |
fec6c20b MG |
142 | { |
143 | /* A single 16-bit integer */ | |
144 | if (len != 2) | |
145 | return false; | |
146 | ||
147 | return true; | |
148 | } | |
149 | ||
150 | static bool | |
a5d92ad3 | 151 | validate_ascii_string(efi_char16_t *var_name, int match, u8 *buffer, |
54b3a4d3 | 152 | unsigned long len) |
fec6c20b MG |
153 | { |
154 | int i; | |
155 | ||
156 | for (i = 0; i < len; i++) { | |
157 | if (buffer[i] > 127) | |
158 | return false; | |
159 | ||
160 | if (buffer[i] == 0) | |
161 | return true; | |
162 | } | |
163 | ||
164 | return false; | |
165 | } | |
166 | ||
167 | struct variable_validate { | |
168 | char *name; | |
a5d92ad3 | 169 | bool (*validate)(efi_char16_t *var_name, int match, u8 *data, |
54b3a4d3 | 170 | unsigned long len); |
fec6c20b MG |
171 | }; |
172 | ||
173 | static const struct variable_validate variable_validate[] = { | |
174 | { "BootNext", validate_uint16 }, | |
175 | { "BootOrder", validate_boot_order }, | |
176 | { "DriverOrder", validate_boot_order }, | |
177 | { "Boot*", validate_load_option }, | |
178 | { "Driver*", validate_load_option }, | |
179 | { "ConIn", validate_device_path }, | |
180 | { "ConInDev", validate_device_path }, | |
181 | { "ConOut", validate_device_path }, | |
182 | { "ConOutDev", validate_device_path }, | |
183 | { "ErrOut", validate_device_path }, | |
184 | { "ErrOutDev", validate_device_path }, | |
185 | { "Timeout", validate_uint16 }, | |
186 | { "Lang", validate_ascii_string }, | |
187 | { "PlatformLang", validate_ascii_string }, | |
188 | { "", NULL }, | |
189 | }; | |
190 | ||
e14ab23d | 191 | bool |
a5d92ad3 | 192 | efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len) |
fec6c20b MG |
193 | { |
194 | int i; | |
a5d92ad3 | 195 | u16 *unicode_name = var_name; |
fec6c20b MG |
196 | |
197 | for (i = 0; variable_validate[i].validate != NULL; i++) { | |
198 | const char *name = variable_validate[i].name; | |
199 | int match; | |
200 | ||
201 | for (match = 0; ; match++) { | |
202 | char c = name[match]; | |
203 | u16 u = unicode_name[match]; | |
204 | ||
205 | /* All special variables are plain ascii */ | |
206 | if (u > 127) | |
207 | return true; | |
208 | ||
209 | /* Wildcard in the matching name means we've matched */ | |
210 | if (c == '*') | |
a5d92ad3 | 211 | return variable_validate[i].validate(var_name, |
fec6c20b MG |
212 | match, data, len); |
213 | ||
214 | /* Case sensitive match */ | |
215 | if (c != u) | |
216 | break; | |
217 | ||
218 | /* Reached the end of the string while matching */ | |
219 | if (!c) | |
a5d92ad3 | 220 | return variable_validate[i].validate(var_name, |
fec6c20b MG |
221 | match, data, len); |
222 | } | |
223 | } | |
224 | ||
225 | return true; | |
226 | } | |
e14ab23d | 227 | EXPORT_SYMBOL_GPL(efivar_validate); |
fec6c20b | 228 | |
1da177e4 | 229 | static efi_status_t |
e14ab23d | 230 | check_var_size(u32 attributes, unsigned long size) |
68d92986 | 231 | { |
e14ab23d | 232 | const struct efivar_operations *fops = __efivars->ops; |
68d92986 | 233 | |
a614e192 | 234 | if (!fops->query_variable_store) |
68d92986 MG |
235 | return EFI_UNSUPPORTED; |
236 | ||
a614e192 | 237 | return fops->query_variable_store(attributes, size); |
68d92986 MG |
238 | } |
239 | ||
7253eaba MF |
240 | static int efi_status_to_err(efi_status_t status) |
241 | { | |
242 | int err; | |
243 | ||
244 | switch (status) { | |
e14ab23d MF |
245 | case EFI_SUCCESS: |
246 | err = 0; | |
247 | break; | |
7253eaba MF |
248 | case EFI_INVALID_PARAMETER: |
249 | err = -EINVAL; | |
250 | break; | |
251 | case EFI_OUT_OF_RESOURCES: | |
252 | err = -ENOSPC; | |
253 | break; | |
254 | case EFI_DEVICE_ERROR: | |
255 | err = -EIO; | |
256 | break; | |
257 | case EFI_WRITE_PROTECTED: | |
258 | err = -EROFS; | |
259 | break; | |
260 | case EFI_SECURITY_VIOLATION: | |
261 | err = -EACCES; | |
262 | break; | |
263 | case EFI_NOT_FOUND: | |
e14ab23d | 264 | err = -ENOENT; |
7253eaba MF |
265 | break; |
266 | default: | |
267 | err = -EINVAL; | |
268 | } | |
269 | ||
270 | return err; | |
271 | } | |
272 | ||
e14ab23d MF |
273 | static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor, |
274 | struct list_head *head) | |
a93bc0c6 SA |
275 | { |
276 | struct efivar_entry *entry, *n; | |
a93bc0c6 SA |
277 | unsigned long strsize1, strsize2; |
278 | bool found = false; | |
279 | ||
a614e192 | 280 | strsize1 = ucs2_strsize(variable_name, 1024); |
e14ab23d | 281 | list_for_each_entry_safe(entry, n, head, list) { |
a614e192 | 282 | strsize2 = ucs2_strsize(entry->var.VariableName, 1024); |
a93bc0c6 SA |
283 | if (strsize1 == strsize2 && |
284 | !memcmp(variable_name, &(entry->var.VariableName), | |
285 | strsize2) && | |
286 | !efi_guidcmp(entry->var.VendorGuid, | |
287 | *vendor)) { | |
288 | found = true; | |
289 | break; | |
290 | } | |
291 | } | |
292 | return found; | |
293 | } | |
294 | ||
ec50bd32 MF |
295 | /* |
296 | * Returns the size of variable_name, in bytes, including the | |
297 | * terminating NULL character, or variable_name_size if no NULL | |
298 | * character is found among the first variable_name_size bytes. | |
299 | */ | |
300 | static unsigned long var_name_strnsize(efi_char16_t *variable_name, | |
301 | unsigned long variable_name_size) | |
302 | { | |
303 | unsigned long len; | |
304 | efi_char16_t c; | |
305 | ||
306 | /* | |
307 | * The variable name is, by definition, a NULL-terminated | |
308 | * string, so make absolutely sure that variable_name_size is | |
309 | * the value we expect it to be. If not, return the real size. | |
310 | */ | |
311 | for (len = 2; len <= variable_name_size; len += sizeof(c)) { | |
312 | c = variable_name[(len / sizeof(c)) - 1]; | |
313 | if (!c) | |
314 | break; | |
315 | } | |
316 | ||
317 | return min(len, variable_name_size); | |
318 | } | |
319 | ||
e971318b MF |
320 | /* |
321 | * Print a warning when duplicate EFI variables are encountered and | |
322 | * disable the sysfs workqueue since the firmware is buggy. | |
323 | */ | |
b2fce819 | 324 | static void dup_variable_bug(efi_char16_t *str16, efi_guid_t *vendor_guid, |
e971318b MF |
325 | unsigned long len16) |
326 | { | |
327 | size_t i, len8 = len16 / sizeof(efi_char16_t); | |
b2fce819 | 328 | char *str8; |
e971318b MF |
329 | |
330 | /* | |
331 | * Disable the workqueue since the algorithm it uses for | |
332 | * detecting new variables won't work with this buggy | |
333 | * implementation of GetNextVariableName(). | |
334 | */ | |
335 | efivar_wq_enabled = false; | |
336 | ||
b2fce819 MR |
337 | str8 = kzalloc(len8, GFP_KERNEL); |
338 | if (!str8) | |
e971318b MF |
339 | return; |
340 | ||
341 | for (i = 0; i < len8; i++) | |
b2fce819 | 342 | str8[i] = str16[i]; |
e971318b MF |
343 | |
344 | printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", | |
b2fce819 MR |
345 | str8, vendor_guid); |
346 | kfree(str8); | |
e971318b MF |
347 | } |
348 | ||
e14ab23d MF |
349 | /** |
350 | * efivar_init - build the initial list of EFI variables | |
351 | * @func: callback function to invoke for every variable | |
352 | * @data: function-specific data to pass to @func | |
353 | * @atomic: do we need to execute the @func-loop atomically? | |
354 | * @duplicates: error if we encounter duplicates on @head? | |
355 | * @head: initialised head of variable list | |
356 | * | |
357 | * Get every EFI variable from the firmware and invoke @func. @func | |
358 | * should call efivar_entry_add() to build the list of variables. | |
359 | * | |
360 | * Returns 0 on success, or a kernel error code on failure. | |
361 | */ | |
362 | int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *), | |
363 | void *data, bool atomic, bool duplicates, | |
364 | struct list_head *head) | |
365 | { | |
366 | const struct efivar_operations *ops = __efivars->ops; | |
367 | unsigned long variable_name_size = 1024; | |
368 | efi_char16_t *variable_name; | |
369 | efi_status_t status; | |
370 | efi_guid_t vendor_guid; | |
371 | int err = 0; | |
372 | ||
373 | variable_name = kzalloc(variable_name_size, GFP_KERNEL); | |
374 | if (!variable_name) { | |
375 | printk(KERN_ERR "efivars: Memory allocation failed.\n"); | |
376 | return -ENOMEM; | |
605e70c7 LCY |
377 | } |
378 | ||
e14ab23d MF |
379 | spin_lock_irq(&__efivars->lock); |
380 | ||
1da177e4 LT |
381 | /* |
382 | * Per EFI spec, the maximum storage allocated for both | |
383 | * the variable name and variable data is 1024 bytes. | |
384 | */ | |
385 | ||
386 | do { | |
387 | variable_name_size = 1024; | |
388 | ||
3295814d | 389 | status = ops->get_next_variable(&variable_name_size, |
1da177e4 LT |
390 | variable_name, |
391 | &vendor_guid); | |
392 | switch (status) { | |
393 | case EFI_SUCCESS: | |
e14ab23d MF |
394 | if (!atomic) |
395 | spin_unlock_irq(&__efivars->lock); | |
396 | ||
ec50bd32 MF |
397 | variable_name_size = var_name_strnsize(variable_name, |
398 | variable_name_size); | |
e971318b MF |
399 | |
400 | /* | |
401 | * Some firmware implementations return the | |
402 | * same variable name on multiple calls to | |
403 | * get_next_variable(). Terminate the loop | |
404 | * immediately as there is no guarantee that | |
405 | * we'll ever see a different variable name, | |
406 | * and may end up looping here forever. | |
407 | */ | |
e14ab23d MF |
408 | if (duplicates && |
409 | variable_is_present(variable_name, &vendor_guid, head)) { | |
e971318b MF |
410 | dup_variable_bug(variable_name, &vendor_guid, |
411 | variable_name_size); | |
e14ab23d MF |
412 | if (!atomic) |
413 | spin_lock_irq(&__efivars->lock); | |
414 | ||
e971318b MF |
415 | status = EFI_NOT_FOUND; |
416 | break; | |
417 | } | |
418 | ||
e14ab23d MF |
419 | err = func(variable_name, vendor_guid, variable_name_size, data); |
420 | if (err) | |
421 | status = EFI_NOT_FOUND; | |
422 | ||
423 | if (!atomic) | |
424 | spin_lock_irq(&__efivars->lock); | |
425 | ||
1da177e4 LT |
426 | break; |
427 | case EFI_NOT_FOUND: | |
428 | break; | |
429 | default: | |
430 | printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", | |
431 | status); | |
432 | status = EFI_NOT_FOUND; | |
433 | break; | |
434 | } | |
e14ab23d | 435 | |
1da177e4 LT |
436 | } while (status != EFI_NOT_FOUND); |
437 | ||
e14ab23d MF |
438 | spin_unlock_irq(&__efivars->lock); |
439 | ||
440 | kfree(variable_name); | |
441 | ||
442 | return err; | |
443 | } | |
444 | EXPORT_SYMBOL_GPL(efivar_init); | |
445 | ||
446 | /** | |
447 | * efivar_entry_add - add entry to variable list | |
448 | * @entry: entry to add to list | |
449 | * @head: list head | |
450 | */ | |
451 | void efivar_entry_add(struct efivar_entry *entry, struct list_head *head) | |
452 | { | |
453 | spin_lock_irq(&__efivars->lock); | |
454 | list_add(&entry->list, head); | |
455 | spin_unlock_irq(&__efivars->lock); | |
456 | } | |
457 | EXPORT_SYMBOL_GPL(efivar_entry_add); | |
458 | ||
459 | /** | |
460 | * efivar_entry_remove - remove entry from variable list | |
461 | * @entry: entry to remove from list | |
462 | */ | |
463 | void efivar_entry_remove(struct efivar_entry *entry) | |
464 | { | |
465 | spin_lock_irq(&__efivars->lock); | |
466 | list_del(&entry->list); | |
467 | spin_unlock_irq(&__efivars->lock); | |
468 | } | |
469 | EXPORT_SYMBOL_GPL(efivar_entry_remove); | |
470 | ||
471 | /* | |
472 | * efivar_entry_list_del_unlock - remove entry from variable list | |
473 | * @entry: entry to remove | |
474 | * | |
475 | * Remove @entry from the variable list and release the list lock. | |
476 | * | |
477 | * NOTE: slightly weird locking semantics here - we expect to be | |
478 | * called with the efivars lock already held, and we release it before | |
479 | * returning. This is because this function is usually called after | |
480 | * set_variable() while the lock is still held. | |
481 | */ | |
482 | static void efivar_entry_list_del_unlock(struct efivar_entry *entry) | |
483 | { | |
484 | WARN_ON(!spin_is_locked(&__efivars->lock)); | |
485 | ||
486 | list_del(&entry->list); | |
487 | spin_unlock_irq(&__efivars->lock); | |
488 | } | |
489 | ||
490 | /** | |
491 | * __efivar_entry_delete - delete an EFI variable | |
492 | * @entry: entry containing EFI variable to delete | |
493 | * | |
a9499fa7 TG |
494 | * Delete the variable from the firmware but leave @entry on the |
495 | * variable list. | |
e14ab23d | 496 | * |
a9499fa7 TG |
497 | * This function differs from efivar_entry_delete() because it does |
498 | * not remove @entry from the variable list. Also, it is safe to be | |
499 | * called from within a efivar_entry_iter_begin() and | |
e14ab23d MF |
500 | * efivar_entry_iter_end() region, unlike efivar_entry_delete(). |
501 | * | |
502 | * Returns 0 on success, or a converted EFI status code if | |
a9499fa7 | 503 | * set_variable() fails. |
e14ab23d MF |
504 | */ |
505 | int __efivar_entry_delete(struct efivar_entry *entry) | |
506 | { | |
507 | const struct efivar_operations *ops = __efivars->ops; | |
508 | efi_status_t status; | |
509 | ||
510 | WARN_ON(!spin_is_locked(&__efivars->lock)); | |
511 | ||
512 | status = ops->set_variable(entry->var.VariableName, | |
513 | &entry->var.VendorGuid, | |
514 | 0, 0, NULL); | |
e14ab23d | 515 | |
a9499fa7 | 516 | return efi_status_to_err(status); |
e14ab23d MF |
517 | } |
518 | EXPORT_SYMBOL_GPL(__efivar_entry_delete); | |
519 | ||
520 | /** | |
521 | * efivar_entry_delete - delete variable and remove entry from list | |
522 | * @entry: entry containing variable to delete | |
523 | * | |
524 | * Delete the variable from the firmware and remove @entry from the | |
525 | * variable list. It is the caller's responsibility to free @entry | |
526 | * once we return. | |
527 | * | |
528 | * Returns 0 on success, or a converted EFI status code if | |
529 | * set_variable() fails. | |
530 | */ | |
531 | int efivar_entry_delete(struct efivar_entry *entry) | |
532 | { | |
533 | const struct efivar_operations *ops = __efivars->ops; | |
534 | efi_status_t status; | |
535 | ||
536 | spin_lock_irq(&__efivars->lock); | |
537 | status = ops->set_variable(entry->var.VariableName, | |
538 | &entry->var.VendorGuid, | |
539 | 0, 0, NULL); | |
540 | if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) { | |
541 | spin_unlock_irq(&__efivars->lock); | |
542 | return efi_status_to_err(status); | |
543 | } | |
544 | ||
545 | efivar_entry_list_del_unlock(entry); | |
546 | return 0; | |
547 | } | |
548 | EXPORT_SYMBOL_GPL(efivar_entry_delete); | |
549 | ||
550 | /** | |
551 | * efivar_entry_set - call set_variable() | |
552 | * @entry: entry containing the EFI variable to write | |
553 | * @attributes: variable attributes | |
554 | * @size: size of @data buffer | |
555 | * @data: buffer containing variable data | |
556 | * @head: head of variable list | |
557 | * | |
558 | * Calls set_variable() for an EFI variable. If creating a new EFI | |
559 | * variable, this function is usually followed by efivar_entry_add(). | |
560 | * | |
561 | * Before writing the variable, the remaining EFI variable storage | |
562 | * space is checked to ensure there is enough room available. | |
563 | * | |
564 | * If @head is not NULL a lookup is performed to determine whether | |
565 | * the entry is already on the list. | |
566 | * | |
567 | * Returns 0 on success, -EEXIST if a lookup is performed and the entry | |
568 | * already exists on the list, or a converted EFI status code if | |
569 | * set_variable() fails. | |
570 | */ | |
571 | int efivar_entry_set(struct efivar_entry *entry, u32 attributes, | |
572 | unsigned long size, void *data, struct list_head *head) | |
573 | { | |
574 | const struct efivar_operations *ops = __efivars->ops; | |
575 | efi_status_t status; | |
576 | efi_char16_t *name = entry->var.VariableName; | |
577 | efi_guid_t vendor = entry->var.VendorGuid; | |
578 | ||
579 | spin_lock_irq(&__efivars->lock); | |
580 | ||
581 | if (head && efivar_entry_find(name, vendor, head, false)) { | |
582 | spin_unlock_irq(&__efivars->lock); | |
583 | return -EEXIST; | |
584 | } | |
585 | ||
a614e192 | 586 | status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
587 | if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) |
588 | status = ops->set_variable(name, &vendor, | |
589 | attributes, size, data); | |
590 | ||
591 | spin_unlock_irq(&__efivars->lock); | |
592 | ||
593 | return efi_status_to_err(status); | |
a9499fa7 | 594 | |
e14ab23d MF |
595 | } |
596 | EXPORT_SYMBOL_GPL(efivar_entry_set); | |
597 | ||
598 | /** | |
599 | * efivar_entry_set_safe - call set_variable() if enough space in firmware | |
600 | * @name: buffer containing the variable name | |
601 | * @vendor: variable vendor guid | |
602 | * @attributes: variable attributes | |
603 | * @block: can we block in this context? | |
604 | * @size: size of @data buffer | |
605 | * @data: buffer containing variable data | |
606 | * | |
607 | * Ensures there is enough free storage in the firmware for this variable, and | |
608 | * if so, calls set_variable(). If creating a new EFI variable, this function | |
609 | * is usually followed by efivar_entry_add(). | |
610 | * | |
611 | * Returns 0 on success, -ENOSPC if the firmware does not have enough | |
612 | * space for set_variable() to succeed, or a converted EFI status code | |
613 | * if set_variable() fails. | |
614 | */ | |
615 | int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, | |
616 | bool block, unsigned long size, void *data) | |
617 | { | |
618 | const struct efivar_operations *ops = __efivars->ops; | |
619 | unsigned long flags; | |
620 | efi_status_t status; | |
621 | ||
a614e192 | 622 | if (!ops->query_variable_store) |
e14ab23d MF |
623 | return -ENOSYS; |
624 | ||
85c90716 DC |
625 | if (!block) { |
626 | if (!spin_trylock_irqsave(&__efivars->lock, flags)) | |
627 | return -EBUSY; | |
628 | } else { | |
e14ab23d | 629 | spin_lock_irqsave(&__efivars->lock, flags); |
85c90716 | 630 | } |
e14ab23d | 631 | |
a614e192 | 632 | status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
633 | if (status != EFI_SUCCESS) { |
634 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
635 | return -ENOSPC; | |
636 | } | |
637 | ||
638 | status = ops->set_variable(name, &vendor, attributes, size, data); | |
639 | ||
640 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
641 | ||
642 | return efi_status_to_err(status); | |
643 | } | |
644 | EXPORT_SYMBOL_GPL(efivar_entry_set_safe); | |
645 | ||
646 | /** | |
647 | * efivar_entry_find - search for an entry | |
648 | * @name: the EFI variable name | |
649 | * @guid: the EFI variable vendor's guid | |
650 | * @head: head of the variable list | |
651 | * @remove: should we remove the entry from the list? | |
652 | * | |
653 | * Search for an entry on the variable list that has the EFI variable | |
654 | * name @name and vendor guid @guid. If an entry is found on the list | |
655 | * and @remove is true, the entry is removed from the list. | |
656 | * | |
657 | * The caller MUST call efivar_entry_iter_begin() and | |
658 | * efivar_entry_iter_end() before and after the invocation of this | |
659 | * function, respectively. | |
660 | * | |
661 | * Returns the entry if found on the list, %NULL otherwise. | |
662 | */ | |
663 | struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, | |
664 | struct list_head *head, bool remove) | |
665 | { | |
666 | struct efivar_entry *entry, *n; | |
667 | int strsize1, strsize2; | |
668 | bool found = false; | |
669 | ||
670 | WARN_ON(!spin_is_locked(&__efivars->lock)); | |
671 | ||
672 | list_for_each_entry_safe(entry, n, head, list) { | |
a614e192 MF |
673 | strsize1 = ucs2_strsize(name, 1024); |
674 | strsize2 = ucs2_strsize(entry->var.VariableName, 1024); | |
e14ab23d MF |
675 | if (strsize1 == strsize2 && |
676 | !memcmp(name, &(entry->var.VariableName), strsize1) && | |
677 | !efi_guidcmp(guid, entry->var.VendorGuid)) { | |
678 | found = true; | |
679 | break; | |
680 | } | |
681 | } | |
682 | ||
683 | if (!found) | |
684 | return NULL; | |
685 | ||
e0d59733 SA |
686 | if (remove) { |
687 | if (entry->scanning) { | |
688 | /* | |
689 | * The entry will be deleted | |
690 | * after scanning is completed. | |
691 | */ | |
692 | entry->deleting = true; | |
693 | } else | |
694 | list_del(&entry->list); | |
695 | } | |
e14ab23d MF |
696 | |
697 | return entry; | |
698 | } | |
699 | EXPORT_SYMBOL_GPL(efivar_entry_find); | |
700 | ||
701 | /** | |
8a415b8c | 702 | * efivar_entry_size - obtain the size of a variable |
e14ab23d MF |
703 | * @entry: entry for this variable |
704 | * @size: location to store the variable's size | |
e14ab23d | 705 | */ |
8a415b8c | 706 | int efivar_entry_size(struct efivar_entry *entry, unsigned long *size) |
e14ab23d MF |
707 | { |
708 | const struct efivar_operations *ops = __efivars->ops; | |
709 | efi_status_t status; | |
710 | ||
e14ab23d | 711 | *size = 0; |
8a415b8c MF |
712 | |
713 | spin_lock_irq(&__efivars->lock); | |
e14ab23d MF |
714 | status = ops->get_variable(entry->var.VariableName, |
715 | &entry->var.VendorGuid, NULL, size, NULL); | |
8a415b8c MF |
716 | spin_unlock_irq(&__efivars->lock); |
717 | ||
e14ab23d MF |
718 | if (status != EFI_BUFFER_TOO_SMALL) |
719 | return efi_status_to_err(status); | |
720 | ||
721 | return 0; | |
722 | } | |
8a415b8c | 723 | EXPORT_SYMBOL_GPL(efivar_entry_size); |
e14ab23d MF |
724 | |
725 | /** | |
8a415b8c MF |
726 | * __efivar_entry_get - call get_variable() |
727 | * @entry: read data for this variable | |
728 | * @attributes: variable attributes | |
729 | * @size: size of @data buffer | |
730 | * @data: buffer to store variable data | |
731 | * | |
732 | * The caller MUST call efivar_entry_iter_begin() and | |
733 | * efivar_entry_iter_end() before and after the invocation of this | |
734 | * function, respectively. | |
e14ab23d | 735 | */ |
8a415b8c MF |
736 | int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes, |
737 | unsigned long *size, void *data) | |
e14ab23d MF |
738 | { |
739 | const struct efivar_operations *ops = __efivars->ops; | |
740 | efi_status_t status; | |
741 | ||
8a415b8c | 742 | WARN_ON(!spin_is_locked(&__efivars->lock)); |
e14ab23d | 743 | |
e14ab23d | 744 | status = ops->get_variable(entry->var.VariableName, |
8a415b8c MF |
745 | &entry->var.VendorGuid, |
746 | attributes, size, data); | |
e14ab23d | 747 | |
8a415b8c | 748 | return efi_status_to_err(status); |
e14ab23d | 749 | } |
8a415b8c | 750 | EXPORT_SYMBOL_GPL(__efivar_entry_get); |
e14ab23d MF |
751 | |
752 | /** | |
753 | * efivar_entry_get - call get_variable() | |
754 | * @entry: read data for this variable | |
755 | * @attributes: variable attributes | |
756 | * @size: size of @data buffer | |
757 | * @data: buffer to store variable data | |
758 | */ | |
759 | int efivar_entry_get(struct efivar_entry *entry, u32 *attributes, | |
760 | unsigned long *size, void *data) | |
761 | { | |
762 | const struct efivar_operations *ops = __efivars->ops; | |
763 | efi_status_t status; | |
764 | ||
765 | spin_lock_irq(&__efivars->lock); | |
766 | status = ops->get_variable(entry->var.VariableName, | |
767 | &entry->var.VendorGuid, | |
768 | attributes, size, data); | |
769 | spin_unlock_irq(&__efivars->lock); | |
770 | ||
771 | return efi_status_to_err(status); | |
772 | } | |
773 | EXPORT_SYMBOL_GPL(efivar_entry_get); | |
774 | ||
775 | /** | |
776 | * efivar_entry_set_get_size - call set_variable() and get new size (atomic) | |
777 | * @entry: entry containing variable to set and get | |
778 | * @attributes: attributes of variable to be written | |
779 | * @size: size of data buffer | |
780 | * @data: buffer containing data to write | |
781 | * @set: did the set_variable() call succeed? | |
782 | * | |
783 | * This is a pretty special (complex) function. See efivarfs_file_write(). | |
784 | * | |
785 | * Atomically call set_variable() for @entry and if the call is | |
786 | * successful, return the new size of the variable from get_variable() | |
787 | * in @size. The success of set_variable() is indicated by @set. | |
788 | * | |
789 | * Returns 0 on success, -EINVAL if the variable data is invalid, | |
790 | * -ENOSPC if the firmware does not have enough available space, or a | |
791 | * converted EFI status code if either of set_variable() or | |
792 | * get_variable() fail. | |
793 | * | |
794 | * If the EFI variable does not exist when calling set_variable() | |
795 | * (EFI_NOT_FOUND), @entry is removed from the variable list. | |
796 | */ | |
797 | int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, | |
798 | unsigned long *size, void *data, bool *set) | |
799 | { | |
800 | const struct efivar_operations *ops = __efivars->ops; | |
801 | efi_char16_t *name = entry->var.VariableName; | |
802 | efi_guid_t *vendor = &entry->var.VendorGuid; | |
803 | efi_status_t status; | |
804 | int err; | |
805 | ||
806 | *set = false; | |
807 | ||
a5d92ad3 | 808 | if (efivar_validate(name, data, *size) == false) |
e14ab23d MF |
809 | return -EINVAL; |
810 | ||
811 | /* | |
812 | * The lock here protects the get_variable call, the conditional | |
813 | * set_variable call, and removal of the variable from the efivars | |
814 | * list (in the case of an authenticated delete). | |
815 | */ | |
816 | spin_lock_irq(&__efivars->lock); | |
817 | ||
818 | /* | |
819 | * Ensure that the available space hasn't shrunk below the safe level | |
820 | */ | |
a614e192 | 821 | status = check_var_size(attributes, *size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
822 | if (status != EFI_SUCCESS) { |
823 | if (status != EFI_UNSUPPORTED) { | |
824 | err = efi_status_to_err(status); | |
825 | goto out; | |
826 | } | |
827 | ||
828 | if (*size > 65536) { | |
829 | err = -ENOSPC; | |
830 | goto out; | |
831 | } | |
832 | } | |
833 | ||
834 | status = ops->set_variable(name, vendor, attributes, *size, data); | |
835 | if (status != EFI_SUCCESS) { | |
836 | err = efi_status_to_err(status); | |
837 | goto out; | |
838 | } | |
839 | ||
840 | *set = true; | |
841 | ||
842 | /* | |
843 | * Writing to the variable may have caused a change in size (which | |
844 | * could either be an append or an overwrite), or the variable to be | |
845 | * deleted. Perform a GetVariable() so we can tell what actually | |
846 | * happened. | |
847 | */ | |
848 | *size = 0; | |
849 | status = ops->get_variable(entry->var.VariableName, | |
850 | &entry->var.VendorGuid, | |
851 | NULL, size, NULL); | |
852 | ||
853 | if (status == EFI_NOT_FOUND) | |
854 | efivar_entry_list_del_unlock(entry); | |
855 | else | |
856 | spin_unlock_irq(&__efivars->lock); | |
857 | ||
858 | if (status && status != EFI_BUFFER_TOO_SMALL) | |
859 | return efi_status_to_err(status); | |
860 | ||
861 | return 0; | |
862 | ||
863 | out: | |
864 | spin_unlock_irq(&__efivars->lock); | |
865 | return err; | |
866 | ||
867 | } | |
868 | EXPORT_SYMBOL_GPL(efivar_entry_set_get_size); | |
869 | ||
870 | /** | |
871 | * efivar_entry_iter_begin - begin iterating the variable list | |
872 | * | |
873 | * Lock the variable list to prevent entry insertion and removal until | |
874 | * efivar_entry_iter_end() is called. This function is usually used in | |
875 | * conjunction with __efivar_entry_iter() or efivar_entry_iter(). | |
876 | */ | |
877 | void efivar_entry_iter_begin(void) | |
878 | { | |
879 | spin_lock_irq(&__efivars->lock); | |
880 | } | |
881 | EXPORT_SYMBOL_GPL(efivar_entry_iter_begin); | |
882 | ||
883 | /** | |
884 | * efivar_entry_iter_end - finish iterating the variable list | |
885 | * | |
886 | * Unlock the variable list and allow modifications to the list again. | |
887 | */ | |
888 | void efivar_entry_iter_end(void) | |
889 | { | |
890 | spin_unlock_irq(&__efivars->lock); | |
891 | } | |
892 | EXPORT_SYMBOL_GPL(efivar_entry_iter_end); | |
893 | ||
894 | /** | |
895 | * __efivar_entry_iter - iterate over variable list | |
896 | * @func: callback function | |
897 | * @head: head of the variable list | |
898 | * @data: function-specific data to pass to callback | |
899 | * @prev: entry to begin iterating from | |
900 | * | |
901 | * Iterate over the list of EFI variables and call @func with every | |
902 | * entry on the list. It is safe for @func to remove entries in the | |
903 | * list via efivar_entry_delete(). | |
904 | * | |
905 | * You MUST call efivar_enter_iter_begin() before this function, and | |
906 | * efivar_entry_iter_end() afterwards. | |
907 | * | |
908 | * It is possible to begin iteration from an arbitrary entry within | |
909 | * the list by passing @prev. @prev is updated on return to point to | |
910 | * the last entry passed to @func. To begin iterating from the | |
911 | * beginning of the list @prev must be %NULL. | |
912 | * | |
913 | * The restrictions for @func are the same as documented for | |
914 | * efivar_entry_iter(). | |
915 | */ | |
916 | int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *), | |
917 | struct list_head *head, void *data, | |
918 | struct efivar_entry **prev) | |
919 | { | |
920 | struct efivar_entry *entry, *n; | |
921 | int err = 0; | |
922 | ||
923 | if (!prev || !*prev) { | |
924 | list_for_each_entry_safe(entry, n, head, list) { | |
925 | err = func(entry, data); | |
926 | if (err) | |
927 | break; | |
928 | } | |
929 | ||
930 | if (prev) | |
931 | *prev = entry; | |
932 | ||
933 | return err; | |
934 | } | |
935 | ||
936 | ||
937 | list_for_each_entry_safe_continue((*prev), n, head, list) { | |
938 | err = func(*prev, data); | |
939 | if (err) | |
940 | break; | |
941 | } | |
942 | ||
943 | return err; | |
944 | } | |
945 | EXPORT_SYMBOL_GPL(__efivar_entry_iter); | |
946 | ||
947 | /** | |
948 | * efivar_entry_iter - iterate over variable list | |
949 | * @func: callback function | |
950 | * @head: head of variable list | |
951 | * @data: function-specific data to pass to callback | |
952 | * | |
953 | * Iterate over the list of EFI variables and call @func with every | |
954 | * entry on the list. It is safe for @func to remove entries in the | |
955 | * list via efivar_entry_delete() while iterating. | |
956 | * | |
957 | * Some notes for the callback function: | |
958 | * - a non-zero return value indicates an error and terminates the loop | |
959 | * - @func is called from atomic context | |
960 | */ | |
961 | int efivar_entry_iter(int (*func)(struct efivar_entry *, void *), | |
962 | struct list_head *head, void *data) | |
963 | { | |
964 | int err = 0; | |
965 | ||
966 | efivar_entry_iter_begin(); | |
967 | err = __efivar_entry_iter(func, head, data, NULL); | |
968 | efivar_entry_iter_end(); | |
969 | ||
970 | return err; | |
971 | } | |
972 | EXPORT_SYMBOL_GPL(efivar_entry_iter); | |
973 | ||
974 | /** | |
975 | * efivars_kobject - get the kobject for the registered efivars | |
976 | * | |
977 | * If efivars_register() has not been called we return NULL, | |
978 | * otherwise return the kobject used at registration time. | |
979 | */ | |
980 | struct kobject *efivars_kobject(void) | |
981 | { | |
982 | if (!__efivars) | |
983 | return NULL; | |
984 | ||
985 | return __efivars->kobject; | |
986 | } | |
987 | EXPORT_SYMBOL_GPL(efivars_kobject); | |
988 | ||
04851772 MF |
989 | /** |
990 | * efivar_run_worker - schedule the efivar worker thread | |
991 | */ | |
992 | void efivar_run_worker(void) | |
993 | { | |
994 | if (efivar_wq_enabled) | |
995 | schedule_work(&efivar_work); | |
996 | } | |
997 | EXPORT_SYMBOL_GPL(efivar_run_worker); | |
998 | ||
e14ab23d MF |
999 | /** |
1000 | * efivars_register - register an efivars | |
1001 | * @efivars: efivars to register | |
1002 | * @ops: efivars operations | |
1003 | * @kobject: @efivars-specific kobject | |
1004 | * | |
1005 | * Only a single efivars can be registered at any time. | |
1006 | */ | |
1007 | int efivars_register(struct efivars *efivars, | |
1008 | const struct efivar_operations *ops, | |
1009 | struct kobject *kobject) | |
1010 | { | |
1011 | spin_lock_init(&efivars->lock); | |
1012 | efivars->ops = ops; | |
1013 | efivars->kobject = kobject; | |
1014 | ||
1015 | __efivars = efivars; | |
1da177e4 | 1016 | |
e14ab23d MF |
1017 | return 0; |
1018 | } | |
1019 | EXPORT_SYMBOL_GPL(efivars_register); | |
1da177e4 | 1020 | |
e14ab23d MF |
1021 | /** |
1022 | * efivars_unregister - unregister an efivars | |
1023 | * @efivars: efivars to unregister | |
1024 | * | |
1025 | * The caller must have already removed every entry from the list, | |
1026 | * failure to do so is an error. | |
1027 | */ | |
1028 | int efivars_unregister(struct efivars *efivars) | |
1029 | { | |
1030 | int rv; | |
1031 | ||
1032 | if (!__efivars) { | |
1033 | printk(KERN_ERR "efivars not registered\n"); | |
1034 | rv = -EINVAL; | |
1035 | goto out; | |
1036 | } | |
1037 | ||
1038 | if (__efivars != efivars) { | |
1039 | rv = -EINVAL; | |
1040 | goto out; | |
1041 | } | |
1042 | ||
1043 | __efivars = NULL; | |
1044 | ||
1045 | rv = 0; | |
1046 | out: | |
1047 | return rv; | |
76b53f7c | 1048 | } |
e14ab23d | 1049 | EXPORT_SYMBOL_GPL(efivars_unregister); |