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 { | |
8282f5d9 | 168 | efi_guid_t vendor; |
fec6c20b | 169 | char *name; |
a5d92ad3 | 170 | bool (*validate)(efi_char16_t *var_name, int match, u8 *data, |
54b3a4d3 | 171 | unsigned long len); |
fec6c20b MG |
172 | }; |
173 | ||
8282f5d9 PJ |
174 | /* |
175 | * This is the list of variables we need to validate. | |
176 | * | |
177 | * If it has a validate() method that's not NULL, it'll go into the | |
178 | * validation routine. If not, it is assumed valid. | |
179 | * | |
180 | * Note that it's sorted by {vendor,name}, but globbed names must come after | |
181 | * any other name with the same prefix. | |
182 | */ | |
fec6c20b | 183 | static const struct variable_validate variable_validate[] = { |
8282f5d9 PJ |
184 | { EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 }, |
185 | { EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order }, | |
186 | { EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option }, | |
187 | { EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order }, | |
188 | { EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option }, | |
189 | { EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path }, | |
190 | { EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path }, | |
191 | { EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path }, | |
192 | { EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path }, | |
193 | { EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path }, | |
194 | { EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path }, | |
195 | { EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string }, | |
196 | { EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string }, | |
197 | { EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 }, | |
198 | { NULL_GUID, "", NULL }, | |
fec6c20b MG |
199 | }; |
200 | ||
e14ab23d | 201 | bool |
8282f5d9 PJ |
202 | efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data, |
203 | unsigned long data_size) | |
fec6c20b MG |
204 | { |
205 | int i; | |
3dcb1f55 PJ |
206 | unsigned long utf8_size; |
207 | u8 *utf8_name; | |
208 | ||
209 | utf8_size = ucs2_utf8size(var_name); | |
210 | utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL); | |
211 | if (!utf8_name) | |
212 | return false; | |
213 | ||
214 | ucs2_as_utf8(utf8_name, var_name, utf8_size); | |
215 | utf8_name[utf8_size] = '\0'; | |
fec6c20b | 216 | |
8282f5d9 | 217 | for (i = 0; variable_validate[i].name[0] != '\0'; i++) { |
fec6c20b | 218 | const char *name = variable_validate[i].name; |
8282f5d9 PJ |
219 | int match = 0; |
220 | ||
221 | if (efi_guidcmp(vendor, variable_validate[i].vendor)) | |
222 | continue; | |
fec6c20b MG |
223 | |
224 | for (match = 0; ; match++) { | |
225 | char c = name[match]; | |
3dcb1f55 | 226 | char u = utf8_name[match]; |
fec6c20b MG |
227 | |
228 | /* Wildcard in the matching name means we've matched */ | |
3dcb1f55 PJ |
229 | if (c == '*') { |
230 | kfree(utf8_name); | |
a5d92ad3 | 231 | return variable_validate[i].validate(var_name, |
3dcb1f55 PJ |
232 | match, data, data_size); |
233 | } | |
fec6c20b MG |
234 | |
235 | /* Case sensitive match */ | |
236 | if (c != u) | |
237 | break; | |
238 | ||
239 | /* Reached the end of the string while matching */ | |
3dcb1f55 PJ |
240 | if (!c) { |
241 | kfree(utf8_name); | |
a5d92ad3 | 242 | return variable_validate[i].validate(var_name, |
3dcb1f55 PJ |
243 | match, data, data_size); |
244 | } | |
fec6c20b MG |
245 | } |
246 | } | |
247 | ||
3dcb1f55 | 248 | kfree(utf8_name); |
fec6c20b MG |
249 | return true; |
250 | } | |
e14ab23d | 251 | EXPORT_SYMBOL_GPL(efivar_validate); |
fec6c20b | 252 | |
1da177e4 | 253 | static efi_status_t |
e14ab23d | 254 | check_var_size(u32 attributes, unsigned long size) |
68d92986 | 255 | { |
e14ab23d | 256 | const struct efivar_operations *fops = __efivars->ops; |
68d92986 | 257 | |
a614e192 | 258 | if (!fops->query_variable_store) |
68d92986 MG |
259 | return EFI_UNSUPPORTED; |
260 | ||
a614e192 | 261 | return fops->query_variable_store(attributes, size); |
68d92986 MG |
262 | } |
263 | ||
7253eaba MF |
264 | static int efi_status_to_err(efi_status_t status) |
265 | { | |
266 | int err; | |
267 | ||
268 | switch (status) { | |
e14ab23d MF |
269 | case EFI_SUCCESS: |
270 | err = 0; | |
271 | break; | |
7253eaba MF |
272 | case EFI_INVALID_PARAMETER: |
273 | err = -EINVAL; | |
274 | break; | |
275 | case EFI_OUT_OF_RESOURCES: | |
276 | err = -ENOSPC; | |
277 | break; | |
278 | case EFI_DEVICE_ERROR: | |
279 | err = -EIO; | |
280 | break; | |
281 | case EFI_WRITE_PROTECTED: | |
282 | err = -EROFS; | |
283 | break; | |
284 | case EFI_SECURITY_VIOLATION: | |
285 | err = -EACCES; | |
286 | break; | |
287 | case EFI_NOT_FOUND: | |
e14ab23d | 288 | err = -ENOENT; |
7253eaba MF |
289 | break; |
290 | default: | |
291 | err = -EINVAL; | |
292 | } | |
293 | ||
294 | return err; | |
295 | } | |
296 | ||
e14ab23d MF |
297 | static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor, |
298 | struct list_head *head) | |
a93bc0c6 SA |
299 | { |
300 | struct efivar_entry *entry, *n; | |
a93bc0c6 SA |
301 | unsigned long strsize1, strsize2; |
302 | bool found = false; | |
303 | ||
a614e192 | 304 | strsize1 = ucs2_strsize(variable_name, 1024); |
e14ab23d | 305 | list_for_each_entry_safe(entry, n, head, list) { |
a614e192 | 306 | strsize2 = ucs2_strsize(entry->var.VariableName, 1024); |
a93bc0c6 SA |
307 | if (strsize1 == strsize2 && |
308 | !memcmp(variable_name, &(entry->var.VariableName), | |
309 | strsize2) && | |
310 | !efi_guidcmp(entry->var.VendorGuid, | |
311 | *vendor)) { | |
312 | found = true; | |
313 | break; | |
314 | } | |
315 | } | |
316 | return found; | |
317 | } | |
318 | ||
ec50bd32 MF |
319 | /* |
320 | * Returns the size of variable_name, in bytes, including the | |
321 | * terminating NULL character, or variable_name_size if no NULL | |
322 | * character is found among the first variable_name_size bytes. | |
323 | */ | |
324 | static unsigned long var_name_strnsize(efi_char16_t *variable_name, | |
325 | unsigned long variable_name_size) | |
326 | { | |
327 | unsigned long len; | |
328 | efi_char16_t c; | |
329 | ||
330 | /* | |
331 | * The variable name is, by definition, a NULL-terminated | |
332 | * string, so make absolutely sure that variable_name_size is | |
333 | * the value we expect it to be. If not, return the real size. | |
334 | */ | |
335 | for (len = 2; len <= variable_name_size; len += sizeof(c)) { | |
336 | c = variable_name[(len / sizeof(c)) - 1]; | |
337 | if (!c) | |
338 | break; | |
339 | } | |
340 | ||
341 | return min(len, variable_name_size); | |
342 | } | |
343 | ||
e971318b MF |
344 | /* |
345 | * Print a warning when duplicate EFI variables are encountered and | |
346 | * disable the sysfs workqueue since the firmware is buggy. | |
347 | */ | |
b2fce819 | 348 | static void dup_variable_bug(efi_char16_t *str16, efi_guid_t *vendor_guid, |
e971318b MF |
349 | unsigned long len16) |
350 | { | |
351 | size_t i, len8 = len16 / sizeof(efi_char16_t); | |
b2fce819 | 352 | char *str8; |
e971318b MF |
353 | |
354 | /* | |
355 | * Disable the workqueue since the algorithm it uses for | |
356 | * detecting new variables won't work with this buggy | |
357 | * implementation of GetNextVariableName(). | |
358 | */ | |
359 | efivar_wq_enabled = false; | |
360 | ||
b2fce819 MR |
361 | str8 = kzalloc(len8, GFP_KERNEL); |
362 | if (!str8) | |
e971318b MF |
363 | return; |
364 | ||
365 | for (i = 0; i < len8; i++) | |
b2fce819 | 366 | str8[i] = str16[i]; |
e971318b MF |
367 | |
368 | printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", | |
b2fce819 MR |
369 | str8, vendor_guid); |
370 | kfree(str8); | |
e971318b MF |
371 | } |
372 | ||
e14ab23d MF |
373 | /** |
374 | * efivar_init - build the initial list of EFI variables | |
375 | * @func: callback function to invoke for every variable | |
376 | * @data: function-specific data to pass to @func | |
377 | * @atomic: do we need to execute the @func-loop atomically? | |
378 | * @duplicates: error if we encounter duplicates on @head? | |
379 | * @head: initialised head of variable list | |
380 | * | |
381 | * Get every EFI variable from the firmware and invoke @func. @func | |
382 | * should call efivar_entry_add() to build the list of variables. | |
383 | * | |
384 | * Returns 0 on success, or a kernel error code on failure. | |
385 | */ | |
386 | int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *), | |
387 | void *data, bool atomic, bool duplicates, | |
388 | struct list_head *head) | |
389 | { | |
390 | const struct efivar_operations *ops = __efivars->ops; | |
391 | unsigned long variable_name_size = 1024; | |
392 | efi_char16_t *variable_name; | |
393 | efi_status_t status; | |
394 | efi_guid_t vendor_guid; | |
395 | int err = 0; | |
396 | ||
397 | variable_name = kzalloc(variable_name_size, GFP_KERNEL); | |
398 | if (!variable_name) { | |
399 | printk(KERN_ERR "efivars: Memory allocation failed.\n"); | |
400 | return -ENOMEM; | |
605e70c7 LCY |
401 | } |
402 | ||
e14ab23d MF |
403 | spin_lock_irq(&__efivars->lock); |
404 | ||
1da177e4 LT |
405 | /* |
406 | * Per EFI spec, the maximum storage allocated for both | |
407 | * the variable name and variable data is 1024 bytes. | |
408 | */ | |
409 | ||
410 | do { | |
411 | variable_name_size = 1024; | |
412 | ||
3295814d | 413 | status = ops->get_next_variable(&variable_name_size, |
1da177e4 LT |
414 | variable_name, |
415 | &vendor_guid); | |
416 | switch (status) { | |
417 | case EFI_SUCCESS: | |
e14ab23d MF |
418 | if (!atomic) |
419 | spin_unlock_irq(&__efivars->lock); | |
420 | ||
ec50bd32 MF |
421 | variable_name_size = var_name_strnsize(variable_name, |
422 | variable_name_size); | |
e971318b MF |
423 | |
424 | /* | |
425 | * Some firmware implementations return the | |
426 | * same variable name on multiple calls to | |
427 | * get_next_variable(). Terminate the loop | |
428 | * immediately as there is no guarantee that | |
429 | * we'll ever see a different variable name, | |
430 | * and may end up looping here forever. | |
431 | */ | |
e14ab23d MF |
432 | if (duplicates && |
433 | variable_is_present(variable_name, &vendor_guid, head)) { | |
e971318b MF |
434 | dup_variable_bug(variable_name, &vendor_guid, |
435 | variable_name_size); | |
e14ab23d MF |
436 | if (!atomic) |
437 | spin_lock_irq(&__efivars->lock); | |
438 | ||
e971318b MF |
439 | status = EFI_NOT_FOUND; |
440 | break; | |
441 | } | |
442 | ||
e14ab23d MF |
443 | err = func(variable_name, vendor_guid, variable_name_size, data); |
444 | if (err) | |
445 | status = EFI_NOT_FOUND; | |
446 | ||
447 | if (!atomic) | |
448 | spin_lock_irq(&__efivars->lock); | |
449 | ||
1da177e4 LT |
450 | break; |
451 | case EFI_NOT_FOUND: | |
452 | break; | |
453 | default: | |
454 | printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", | |
455 | status); | |
456 | status = EFI_NOT_FOUND; | |
457 | break; | |
458 | } | |
e14ab23d | 459 | |
1da177e4 LT |
460 | } while (status != EFI_NOT_FOUND); |
461 | ||
e14ab23d MF |
462 | spin_unlock_irq(&__efivars->lock); |
463 | ||
464 | kfree(variable_name); | |
465 | ||
466 | return err; | |
467 | } | |
468 | EXPORT_SYMBOL_GPL(efivar_init); | |
469 | ||
470 | /** | |
471 | * efivar_entry_add - add entry to variable list | |
472 | * @entry: entry to add to list | |
473 | * @head: list head | |
474 | */ | |
475 | void efivar_entry_add(struct efivar_entry *entry, struct list_head *head) | |
476 | { | |
477 | spin_lock_irq(&__efivars->lock); | |
478 | list_add(&entry->list, head); | |
479 | spin_unlock_irq(&__efivars->lock); | |
480 | } | |
481 | EXPORT_SYMBOL_GPL(efivar_entry_add); | |
482 | ||
483 | /** | |
484 | * efivar_entry_remove - remove entry from variable list | |
485 | * @entry: entry to remove from list | |
486 | */ | |
487 | void efivar_entry_remove(struct efivar_entry *entry) | |
488 | { | |
489 | spin_lock_irq(&__efivars->lock); | |
490 | list_del(&entry->list); | |
491 | spin_unlock_irq(&__efivars->lock); | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(efivar_entry_remove); | |
494 | ||
495 | /* | |
496 | * efivar_entry_list_del_unlock - remove entry from variable list | |
497 | * @entry: entry to remove | |
498 | * | |
499 | * Remove @entry from the variable list and release the list lock. | |
500 | * | |
501 | * NOTE: slightly weird locking semantics here - we expect to be | |
502 | * called with the efivars lock already held, and we release it before | |
503 | * returning. This is because this function is usually called after | |
504 | * set_variable() while the lock is still held. | |
505 | */ | |
506 | static void efivar_entry_list_del_unlock(struct efivar_entry *entry) | |
507 | { | |
aee530cf | 508 | lockdep_assert_held(&__efivars->lock); |
e14ab23d MF |
509 | |
510 | list_del(&entry->list); | |
511 | spin_unlock_irq(&__efivars->lock); | |
512 | } | |
513 | ||
514 | /** | |
515 | * __efivar_entry_delete - delete an EFI variable | |
516 | * @entry: entry containing EFI variable to delete | |
517 | * | |
a9499fa7 TG |
518 | * Delete the variable from the firmware but leave @entry on the |
519 | * variable list. | |
e14ab23d | 520 | * |
a9499fa7 TG |
521 | * This function differs from efivar_entry_delete() because it does |
522 | * not remove @entry from the variable list. Also, it is safe to be | |
523 | * called from within a efivar_entry_iter_begin() and | |
e14ab23d MF |
524 | * efivar_entry_iter_end() region, unlike efivar_entry_delete(). |
525 | * | |
526 | * Returns 0 on success, or a converted EFI status code if | |
a9499fa7 | 527 | * set_variable() fails. |
e14ab23d MF |
528 | */ |
529 | int __efivar_entry_delete(struct efivar_entry *entry) | |
530 | { | |
531 | const struct efivar_operations *ops = __efivars->ops; | |
532 | efi_status_t status; | |
533 | ||
aee530cf | 534 | lockdep_assert_held(&__efivars->lock); |
e14ab23d MF |
535 | |
536 | status = ops->set_variable(entry->var.VariableName, | |
537 | &entry->var.VendorGuid, | |
538 | 0, 0, NULL); | |
e14ab23d | 539 | |
a9499fa7 | 540 | return efi_status_to_err(status); |
e14ab23d MF |
541 | } |
542 | EXPORT_SYMBOL_GPL(__efivar_entry_delete); | |
543 | ||
544 | /** | |
545 | * efivar_entry_delete - delete variable and remove entry from list | |
546 | * @entry: entry containing variable to delete | |
547 | * | |
548 | * Delete the variable from the firmware and remove @entry from the | |
549 | * variable list. It is the caller's responsibility to free @entry | |
550 | * once we return. | |
551 | * | |
552 | * Returns 0 on success, or a converted EFI status code if | |
553 | * set_variable() fails. | |
554 | */ | |
555 | int efivar_entry_delete(struct efivar_entry *entry) | |
556 | { | |
557 | const struct efivar_operations *ops = __efivars->ops; | |
558 | efi_status_t status; | |
559 | ||
560 | spin_lock_irq(&__efivars->lock); | |
561 | status = ops->set_variable(entry->var.VariableName, | |
562 | &entry->var.VendorGuid, | |
563 | 0, 0, NULL); | |
564 | if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) { | |
565 | spin_unlock_irq(&__efivars->lock); | |
566 | return efi_status_to_err(status); | |
567 | } | |
568 | ||
569 | efivar_entry_list_del_unlock(entry); | |
570 | return 0; | |
571 | } | |
572 | EXPORT_SYMBOL_GPL(efivar_entry_delete); | |
573 | ||
574 | /** | |
575 | * efivar_entry_set - call set_variable() | |
576 | * @entry: entry containing the EFI variable to write | |
577 | * @attributes: variable attributes | |
578 | * @size: size of @data buffer | |
579 | * @data: buffer containing variable data | |
580 | * @head: head of variable list | |
581 | * | |
582 | * Calls set_variable() for an EFI variable. If creating a new EFI | |
583 | * variable, this function is usually followed by efivar_entry_add(). | |
584 | * | |
585 | * Before writing the variable, the remaining EFI variable storage | |
586 | * space is checked to ensure there is enough room available. | |
587 | * | |
588 | * If @head is not NULL a lookup is performed to determine whether | |
589 | * the entry is already on the list. | |
590 | * | |
591 | * Returns 0 on success, -EEXIST if a lookup is performed and the entry | |
592 | * already exists on the list, or a converted EFI status code if | |
593 | * set_variable() fails. | |
594 | */ | |
595 | int efivar_entry_set(struct efivar_entry *entry, u32 attributes, | |
596 | unsigned long size, void *data, struct list_head *head) | |
597 | { | |
598 | const struct efivar_operations *ops = __efivars->ops; | |
599 | efi_status_t status; | |
600 | efi_char16_t *name = entry->var.VariableName; | |
601 | efi_guid_t vendor = entry->var.VendorGuid; | |
602 | ||
603 | spin_lock_irq(&__efivars->lock); | |
604 | ||
605 | if (head && efivar_entry_find(name, vendor, head, false)) { | |
606 | spin_unlock_irq(&__efivars->lock); | |
607 | return -EEXIST; | |
608 | } | |
609 | ||
a614e192 | 610 | status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
611 | if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) |
612 | status = ops->set_variable(name, &vendor, | |
613 | attributes, size, data); | |
614 | ||
615 | spin_unlock_irq(&__efivars->lock); | |
616 | ||
617 | return efi_status_to_err(status); | |
a9499fa7 | 618 | |
e14ab23d MF |
619 | } |
620 | EXPORT_SYMBOL_GPL(efivar_entry_set); | |
621 | ||
6d80dba1 MF |
622 | /* |
623 | * efivar_entry_set_nonblocking - call set_variable_nonblocking() | |
624 | * | |
625 | * This function is guaranteed to not block and is suitable for calling | |
626 | * from crash/panic handlers. | |
627 | * | |
628 | * Crucially, this function will not block if it cannot acquire | |
629 | * __efivars->lock. Instead, it returns -EBUSY. | |
630 | */ | |
631 | static int | |
632 | efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor, | |
633 | u32 attributes, unsigned long size, void *data) | |
634 | { | |
635 | const struct efivar_operations *ops = __efivars->ops; | |
636 | unsigned long flags; | |
637 | efi_status_t status; | |
638 | ||
639 | if (!spin_trylock_irqsave(&__efivars->lock, flags)) | |
640 | return -EBUSY; | |
641 | ||
642 | status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); | |
643 | if (status != EFI_SUCCESS) { | |
644 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
645 | return -ENOSPC; | |
646 | } | |
647 | ||
648 | status = ops->set_variable_nonblocking(name, &vendor, attributes, | |
649 | size, data); | |
650 | ||
651 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
652 | return efi_status_to_err(status); | |
653 | } | |
654 | ||
e14ab23d MF |
655 | /** |
656 | * efivar_entry_set_safe - call set_variable() if enough space in firmware | |
657 | * @name: buffer containing the variable name | |
658 | * @vendor: variable vendor guid | |
659 | * @attributes: variable attributes | |
660 | * @block: can we block in this context? | |
661 | * @size: size of @data buffer | |
662 | * @data: buffer containing variable data | |
663 | * | |
664 | * Ensures there is enough free storage in the firmware for this variable, and | |
665 | * if so, calls set_variable(). If creating a new EFI variable, this function | |
666 | * is usually followed by efivar_entry_add(). | |
667 | * | |
668 | * Returns 0 on success, -ENOSPC if the firmware does not have enough | |
669 | * space for set_variable() to succeed, or a converted EFI status code | |
670 | * if set_variable() fails. | |
671 | */ | |
672 | int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, | |
673 | bool block, unsigned long size, void *data) | |
674 | { | |
675 | const struct efivar_operations *ops = __efivars->ops; | |
676 | unsigned long flags; | |
677 | efi_status_t status; | |
678 | ||
a614e192 | 679 | if (!ops->query_variable_store) |
e14ab23d MF |
680 | return -ENOSYS; |
681 | ||
6d80dba1 MF |
682 | /* |
683 | * If the EFI variable backend provides a non-blocking | |
684 | * ->set_variable() operation and we're in a context where we | |
685 | * cannot block, then we need to use it to avoid live-locks, | |
686 | * since the implication is that the regular ->set_variable() | |
687 | * will block. | |
688 | * | |
689 | * If no ->set_variable_nonblocking() is provided then | |
690 | * ->set_variable() is assumed to be non-blocking. | |
691 | */ | |
692 | if (!block && ops->set_variable_nonblocking) | |
693 | return efivar_entry_set_nonblocking(name, vendor, attributes, | |
694 | size, data); | |
695 | ||
85c90716 DC |
696 | if (!block) { |
697 | if (!spin_trylock_irqsave(&__efivars->lock, flags)) | |
698 | return -EBUSY; | |
699 | } else { | |
e14ab23d | 700 | spin_lock_irqsave(&__efivars->lock, flags); |
85c90716 | 701 | } |
e14ab23d | 702 | |
a614e192 | 703 | status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
704 | if (status != EFI_SUCCESS) { |
705 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
706 | return -ENOSPC; | |
707 | } | |
708 | ||
709 | status = ops->set_variable(name, &vendor, attributes, size, data); | |
710 | ||
711 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
712 | ||
713 | return efi_status_to_err(status); | |
714 | } | |
715 | EXPORT_SYMBOL_GPL(efivar_entry_set_safe); | |
716 | ||
717 | /** | |
718 | * efivar_entry_find - search for an entry | |
719 | * @name: the EFI variable name | |
720 | * @guid: the EFI variable vendor's guid | |
721 | * @head: head of the variable list | |
722 | * @remove: should we remove the entry from the list? | |
723 | * | |
724 | * Search for an entry on the variable list that has the EFI variable | |
725 | * name @name and vendor guid @guid. If an entry is found on the list | |
726 | * and @remove is true, the entry is removed from the list. | |
727 | * | |
728 | * The caller MUST call efivar_entry_iter_begin() and | |
729 | * efivar_entry_iter_end() before and after the invocation of this | |
730 | * function, respectively. | |
731 | * | |
732 | * Returns the entry if found on the list, %NULL otherwise. | |
733 | */ | |
734 | struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, | |
735 | struct list_head *head, bool remove) | |
736 | { | |
737 | struct efivar_entry *entry, *n; | |
738 | int strsize1, strsize2; | |
739 | bool found = false; | |
740 | ||
aee530cf | 741 | lockdep_assert_held(&__efivars->lock); |
e14ab23d MF |
742 | |
743 | list_for_each_entry_safe(entry, n, head, list) { | |
a614e192 MF |
744 | strsize1 = ucs2_strsize(name, 1024); |
745 | strsize2 = ucs2_strsize(entry->var.VariableName, 1024); | |
e14ab23d MF |
746 | if (strsize1 == strsize2 && |
747 | !memcmp(name, &(entry->var.VariableName), strsize1) && | |
748 | !efi_guidcmp(guid, entry->var.VendorGuid)) { | |
749 | found = true; | |
750 | break; | |
751 | } | |
752 | } | |
753 | ||
754 | if (!found) | |
755 | return NULL; | |
756 | ||
e0d59733 SA |
757 | if (remove) { |
758 | if (entry->scanning) { | |
759 | /* | |
760 | * The entry will be deleted | |
761 | * after scanning is completed. | |
762 | */ | |
763 | entry->deleting = true; | |
764 | } else | |
765 | list_del(&entry->list); | |
766 | } | |
e14ab23d MF |
767 | |
768 | return entry; | |
769 | } | |
770 | EXPORT_SYMBOL_GPL(efivar_entry_find); | |
771 | ||
772 | /** | |
8a415b8c | 773 | * efivar_entry_size - obtain the size of a variable |
e14ab23d MF |
774 | * @entry: entry for this variable |
775 | * @size: location to store the variable's size | |
e14ab23d | 776 | */ |
8a415b8c | 777 | int efivar_entry_size(struct efivar_entry *entry, unsigned long *size) |
e14ab23d MF |
778 | { |
779 | const struct efivar_operations *ops = __efivars->ops; | |
780 | efi_status_t status; | |
781 | ||
e14ab23d | 782 | *size = 0; |
8a415b8c MF |
783 | |
784 | spin_lock_irq(&__efivars->lock); | |
e14ab23d MF |
785 | status = ops->get_variable(entry->var.VariableName, |
786 | &entry->var.VendorGuid, NULL, size, NULL); | |
8a415b8c MF |
787 | spin_unlock_irq(&__efivars->lock); |
788 | ||
e14ab23d MF |
789 | if (status != EFI_BUFFER_TOO_SMALL) |
790 | return efi_status_to_err(status); | |
791 | ||
792 | return 0; | |
793 | } | |
8a415b8c | 794 | EXPORT_SYMBOL_GPL(efivar_entry_size); |
e14ab23d MF |
795 | |
796 | /** | |
8a415b8c MF |
797 | * __efivar_entry_get - call get_variable() |
798 | * @entry: read data for this variable | |
799 | * @attributes: variable attributes | |
800 | * @size: size of @data buffer | |
801 | * @data: buffer to store variable data | |
802 | * | |
803 | * The caller MUST call efivar_entry_iter_begin() and | |
804 | * efivar_entry_iter_end() before and after the invocation of this | |
805 | * function, respectively. | |
e14ab23d | 806 | */ |
8a415b8c MF |
807 | int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes, |
808 | unsigned long *size, void *data) | |
e14ab23d MF |
809 | { |
810 | const struct efivar_operations *ops = __efivars->ops; | |
811 | efi_status_t status; | |
812 | ||
aee530cf | 813 | lockdep_assert_held(&__efivars->lock); |
e14ab23d | 814 | |
e14ab23d | 815 | status = ops->get_variable(entry->var.VariableName, |
8a415b8c MF |
816 | &entry->var.VendorGuid, |
817 | attributes, size, data); | |
e14ab23d | 818 | |
8a415b8c | 819 | return efi_status_to_err(status); |
e14ab23d | 820 | } |
8a415b8c | 821 | EXPORT_SYMBOL_GPL(__efivar_entry_get); |
e14ab23d MF |
822 | |
823 | /** | |
824 | * efivar_entry_get - call get_variable() | |
825 | * @entry: read data for this variable | |
826 | * @attributes: variable attributes | |
827 | * @size: size of @data buffer | |
828 | * @data: buffer to store variable data | |
829 | */ | |
830 | int efivar_entry_get(struct efivar_entry *entry, u32 *attributes, | |
831 | unsigned long *size, void *data) | |
832 | { | |
833 | const struct efivar_operations *ops = __efivars->ops; | |
834 | efi_status_t status; | |
835 | ||
836 | spin_lock_irq(&__efivars->lock); | |
837 | status = ops->get_variable(entry->var.VariableName, | |
838 | &entry->var.VendorGuid, | |
839 | attributes, size, data); | |
840 | spin_unlock_irq(&__efivars->lock); | |
841 | ||
842 | return efi_status_to_err(status); | |
843 | } | |
844 | EXPORT_SYMBOL_GPL(efivar_entry_get); | |
845 | ||
846 | /** | |
847 | * efivar_entry_set_get_size - call set_variable() and get new size (atomic) | |
848 | * @entry: entry containing variable to set and get | |
849 | * @attributes: attributes of variable to be written | |
850 | * @size: size of data buffer | |
851 | * @data: buffer containing data to write | |
852 | * @set: did the set_variable() call succeed? | |
853 | * | |
854 | * This is a pretty special (complex) function. See efivarfs_file_write(). | |
855 | * | |
856 | * Atomically call set_variable() for @entry and if the call is | |
857 | * successful, return the new size of the variable from get_variable() | |
858 | * in @size. The success of set_variable() is indicated by @set. | |
859 | * | |
860 | * Returns 0 on success, -EINVAL if the variable data is invalid, | |
861 | * -ENOSPC if the firmware does not have enough available space, or a | |
862 | * converted EFI status code if either of set_variable() or | |
863 | * get_variable() fail. | |
864 | * | |
865 | * If the EFI variable does not exist when calling set_variable() | |
866 | * (EFI_NOT_FOUND), @entry is removed from the variable list. | |
867 | */ | |
868 | int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, | |
869 | unsigned long *size, void *data, bool *set) | |
870 | { | |
871 | const struct efivar_operations *ops = __efivars->ops; | |
872 | efi_char16_t *name = entry->var.VariableName; | |
873 | efi_guid_t *vendor = &entry->var.VendorGuid; | |
874 | efi_status_t status; | |
875 | int err; | |
876 | ||
877 | *set = false; | |
878 | ||
8282f5d9 | 879 | if (efivar_validate(*vendor, name, data, *size) == false) |
e14ab23d MF |
880 | return -EINVAL; |
881 | ||
882 | /* | |
883 | * The lock here protects the get_variable call, the conditional | |
884 | * set_variable call, and removal of the variable from the efivars | |
885 | * list (in the case of an authenticated delete). | |
886 | */ | |
887 | spin_lock_irq(&__efivars->lock); | |
888 | ||
889 | /* | |
890 | * Ensure that the available space hasn't shrunk below the safe level | |
891 | */ | |
a614e192 | 892 | status = check_var_size(attributes, *size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
893 | if (status != EFI_SUCCESS) { |
894 | if (status != EFI_UNSUPPORTED) { | |
895 | err = efi_status_to_err(status); | |
896 | goto out; | |
897 | } | |
898 | ||
899 | if (*size > 65536) { | |
900 | err = -ENOSPC; | |
901 | goto out; | |
902 | } | |
903 | } | |
904 | ||
905 | status = ops->set_variable(name, vendor, attributes, *size, data); | |
906 | if (status != EFI_SUCCESS) { | |
907 | err = efi_status_to_err(status); | |
908 | goto out; | |
909 | } | |
910 | ||
911 | *set = true; | |
912 | ||
913 | /* | |
914 | * Writing to the variable may have caused a change in size (which | |
915 | * could either be an append or an overwrite), or the variable to be | |
916 | * deleted. Perform a GetVariable() so we can tell what actually | |
917 | * happened. | |
918 | */ | |
919 | *size = 0; | |
920 | status = ops->get_variable(entry->var.VariableName, | |
921 | &entry->var.VendorGuid, | |
922 | NULL, size, NULL); | |
923 | ||
924 | if (status == EFI_NOT_FOUND) | |
925 | efivar_entry_list_del_unlock(entry); | |
926 | else | |
927 | spin_unlock_irq(&__efivars->lock); | |
928 | ||
929 | if (status && status != EFI_BUFFER_TOO_SMALL) | |
930 | return efi_status_to_err(status); | |
931 | ||
932 | return 0; | |
933 | ||
934 | out: | |
935 | spin_unlock_irq(&__efivars->lock); | |
936 | return err; | |
937 | ||
938 | } | |
939 | EXPORT_SYMBOL_GPL(efivar_entry_set_get_size); | |
940 | ||
941 | /** | |
942 | * efivar_entry_iter_begin - begin iterating the variable list | |
943 | * | |
944 | * Lock the variable list to prevent entry insertion and removal until | |
945 | * efivar_entry_iter_end() is called. This function is usually used in | |
946 | * conjunction with __efivar_entry_iter() or efivar_entry_iter(). | |
947 | */ | |
948 | void efivar_entry_iter_begin(void) | |
949 | { | |
950 | spin_lock_irq(&__efivars->lock); | |
951 | } | |
952 | EXPORT_SYMBOL_GPL(efivar_entry_iter_begin); | |
953 | ||
954 | /** | |
955 | * efivar_entry_iter_end - finish iterating the variable list | |
956 | * | |
957 | * Unlock the variable list and allow modifications to the list again. | |
958 | */ | |
959 | void efivar_entry_iter_end(void) | |
960 | { | |
961 | spin_unlock_irq(&__efivars->lock); | |
962 | } | |
963 | EXPORT_SYMBOL_GPL(efivar_entry_iter_end); | |
964 | ||
965 | /** | |
966 | * __efivar_entry_iter - iterate over variable list | |
967 | * @func: callback function | |
968 | * @head: head of the variable list | |
969 | * @data: function-specific data to pass to callback | |
970 | * @prev: entry to begin iterating from | |
971 | * | |
972 | * Iterate over the list of EFI variables and call @func with every | |
973 | * entry on the list. It is safe for @func to remove entries in the | |
974 | * list via efivar_entry_delete(). | |
975 | * | |
976 | * You MUST call efivar_enter_iter_begin() before this function, and | |
977 | * efivar_entry_iter_end() afterwards. | |
978 | * | |
979 | * It is possible to begin iteration from an arbitrary entry within | |
980 | * the list by passing @prev. @prev is updated on return to point to | |
981 | * the last entry passed to @func. To begin iterating from the | |
982 | * beginning of the list @prev must be %NULL. | |
983 | * | |
984 | * The restrictions for @func are the same as documented for | |
985 | * efivar_entry_iter(). | |
986 | */ | |
987 | int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *), | |
988 | struct list_head *head, void *data, | |
989 | struct efivar_entry **prev) | |
990 | { | |
991 | struct efivar_entry *entry, *n; | |
992 | int err = 0; | |
993 | ||
994 | if (!prev || !*prev) { | |
995 | list_for_each_entry_safe(entry, n, head, list) { | |
996 | err = func(entry, data); | |
997 | if (err) | |
998 | break; | |
999 | } | |
1000 | ||
1001 | if (prev) | |
1002 | *prev = entry; | |
1003 | ||
1004 | return err; | |
1005 | } | |
1006 | ||
1007 | ||
1008 | list_for_each_entry_safe_continue((*prev), n, head, list) { | |
1009 | err = func(*prev, data); | |
1010 | if (err) | |
1011 | break; | |
1012 | } | |
1013 | ||
1014 | return err; | |
1015 | } | |
1016 | EXPORT_SYMBOL_GPL(__efivar_entry_iter); | |
1017 | ||
1018 | /** | |
1019 | * efivar_entry_iter - iterate over variable list | |
1020 | * @func: callback function | |
1021 | * @head: head of variable list | |
1022 | * @data: function-specific data to pass to callback | |
1023 | * | |
1024 | * Iterate over the list of EFI variables and call @func with every | |
1025 | * entry on the list. It is safe for @func to remove entries in the | |
1026 | * list via efivar_entry_delete() while iterating. | |
1027 | * | |
1028 | * Some notes for the callback function: | |
1029 | * - a non-zero return value indicates an error and terminates the loop | |
1030 | * - @func is called from atomic context | |
1031 | */ | |
1032 | int efivar_entry_iter(int (*func)(struct efivar_entry *, void *), | |
1033 | struct list_head *head, void *data) | |
1034 | { | |
1035 | int err = 0; | |
1036 | ||
1037 | efivar_entry_iter_begin(); | |
1038 | err = __efivar_entry_iter(func, head, data, NULL); | |
1039 | efivar_entry_iter_end(); | |
1040 | ||
1041 | return err; | |
1042 | } | |
1043 | EXPORT_SYMBOL_GPL(efivar_entry_iter); | |
1044 | ||
1045 | /** | |
1046 | * efivars_kobject - get the kobject for the registered efivars | |
1047 | * | |
1048 | * If efivars_register() has not been called we return NULL, | |
1049 | * otherwise return the kobject used at registration time. | |
1050 | */ | |
1051 | struct kobject *efivars_kobject(void) | |
1052 | { | |
1053 | if (!__efivars) | |
1054 | return NULL; | |
1055 | ||
1056 | return __efivars->kobject; | |
1057 | } | |
1058 | EXPORT_SYMBOL_GPL(efivars_kobject); | |
1059 | ||
04851772 MF |
1060 | /** |
1061 | * efivar_run_worker - schedule the efivar worker thread | |
1062 | */ | |
1063 | void efivar_run_worker(void) | |
1064 | { | |
1065 | if (efivar_wq_enabled) | |
1066 | schedule_work(&efivar_work); | |
1067 | } | |
1068 | EXPORT_SYMBOL_GPL(efivar_run_worker); | |
1069 | ||
e14ab23d MF |
1070 | /** |
1071 | * efivars_register - register an efivars | |
1072 | * @efivars: efivars to register | |
1073 | * @ops: efivars operations | |
1074 | * @kobject: @efivars-specific kobject | |
1075 | * | |
1076 | * Only a single efivars can be registered at any time. | |
1077 | */ | |
1078 | int efivars_register(struct efivars *efivars, | |
1079 | const struct efivar_operations *ops, | |
1080 | struct kobject *kobject) | |
1081 | { | |
1082 | spin_lock_init(&efivars->lock); | |
1083 | efivars->ops = ops; | |
1084 | efivars->kobject = kobject; | |
1085 | ||
1086 | __efivars = efivars; | |
1da177e4 | 1087 | |
e14ab23d MF |
1088 | return 0; |
1089 | } | |
1090 | EXPORT_SYMBOL_GPL(efivars_register); | |
1da177e4 | 1091 | |
e14ab23d MF |
1092 | /** |
1093 | * efivars_unregister - unregister an efivars | |
1094 | * @efivars: efivars to unregister | |
1095 | * | |
1096 | * The caller must have already removed every entry from the list, | |
1097 | * failure to do so is an error. | |
1098 | */ | |
1099 | int efivars_unregister(struct efivars *efivars) | |
1100 | { | |
1101 | int rv; | |
1102 | ||
1103 | if (!__efivars) { | |
1104 | printk(KERN_ERR "efivars not registered\n"); | |
1105 | rv = -EINVAL; | |
1106 | goto out; | |
1107 | } | |
1108 | ||
1109 | if (__efivars != efivars) { | |
1110 | rv = -EINVAL; | |
1111 | goto out; | |
1112 | } | |
1113 | ||
1114 | __efivars = NULL; | |
1115 | ||
1116 | rv = 0; | |
1117 | out: | |
1118 | return rv; | |
76b53f7c | 1119 | } |
e14ab23d | 1120 | EXPORT_SYMBOL_GPL(efivars_unregister); |