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 |
44f21ed1 | 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 | |
44f21ed1 | 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 | |
44f21ed1 | 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 | ||
44f21ed1 | 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++) { | |
44f21ed1 PJ |
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 | */ | |
44f21ed1 | 135 | return validate_device_path(var_name, match, buffer + desclength + 6, |
fec6c20b MG |
136 | filepathlength); |
137 | } | |
138 | ||
139 | static bool | |
44f21ed1 | 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 | |
44f21ed1 | 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 { | |
d591b6da | 168 | efi_guid_t vendor; |
fec6c20b | 169 | char *name; |
44f21ed1 | 170 | bool (*validate)(efi_char16_t *var_name, int match, u8 *data, |
54b3a4d3 | 171 | unsigned long len); |
fec6c20b MG |
172 | }; |
173 | ||
d591b6da | 174 | /* |
7b35014c PJ |
175 | * This is the list of variables we need to validate, as well as the |
176 | * whitelist for what we think is safe not to default to immutable. | |
d591b6da PJ |
177 | * |
178 | * If it has a validate() method that's not NULL, it'll go into the | |
7b35014c PJ |
179 | * validation routine. If not, it is assumed valid, but still used for |
180 | * whitelisting. | |
d591b6da PJ |
181 | * |
182 | * Note that it's sorted by {vendor,name}, but globbed names must come after | |
183 | * any other name with the same prefix. | |
184 | */ | |
fec6c20b | 185 | static const struct variable_validate variable_validate[] = { |
d591b6da PJ |
186 | { EFI_GLOBAL_VARIABLE_GUID, "BootNext", validate_uint16 }, |
187 | { EFI_GLOBAL_VARIABLE_GUID, "BootOrder", validate_boot_order }, | |
188 | { EFI_GLOBAL_VARIABLE_GUID, "Boot*", validate_load_option }, | |
189 | { EFI_GLOBAL_VARIABLE_GUID, "DriverOrder", validate_boot_order }, | |
190 | { EFI_GLOBAL_VARIABLE_GUID, "Driver*", validate_load_option }, | |
191 | { EFI_GLOBAL_VARIABLE_GUID, "ConIn", validate_device_path }, | |
192 | { EFI_GLOBAL_VARIABLE_GUID, "ConInDev", validate_device_path }, | |
193 | { EFI_GLOBAL_VARIABLE_GUID, "ConOut", validate_device_path }, | |
194 | { EFI_GLOBAL_VARIABLE_GUID, "ConOutDev", validate_device_path }, | |
195 | { EFI_GLOBAL_VARIABLE_GUID, "ErrOut", validate_device_path }, | |
196 | { EFI_GLOBAL_VARIABLE_GUID, "ErrOutDev", validate_device_path }, | |
197 | { EFI_GLOBAL_VARIABLE_GUID, "Lang", validate_ascii_string }, | |
7b35014c | 198 | { EFI_GLOBAL_VARIABLE_GUID, "OsIndications", NULL }, |
d591b6da PJ |
199 | { EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string }, |
200 | { EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 }, | |
15b988cf | 201 | { LINUX_EFI_CRASH_GUID, "*", NULL }, |
d591b6da | 202 | { NULL_GUID, "", NULL }, |
fec6c20b MG |
203 | }; |
204 | ||
7b35014c PJ |
205 | static bool |
206 | variable_matches(const char *var_name, size_t len, const char *match_name, | |
207 | int *match) | |
208 | { | |
209 | for (*match = 0; ; (*match)++) { | |
210 | char c = match_name[*match]; | |
211 | char u = var_name[*match]; | |
212 | ||
213 | /* Wildcard in the matching name means we've matched */ | |
214 | if (c == '*') | |
215 | return true; | |
216 | ||
217 | /* Case sensitive match */ | |
218 | if (!c && *match == len) | |
219 | return true; | |
220 | ||
221 | if (c != u) | |
222 | return false; | |
223 | ||
224 | if (!c) | |
225 | return true; | |
226 | } | |
227 | return true; | |
228 | } | |
229 | ||
e14ab23d | 230 | bool |
d591b6da PJ |
231 | efivar_validate(efi_guid_t vendor, efi_char16_t *var_name, u8 *data, |
232 | unsigned long data_size) | |
fec6c20b MG |
233 | { |
234 | int i; | |
44f21ed1 PJ |
235 | unsigned long utf8_size; |
236 | u8 *utf8_name; | |
237 | ||
238 | utf8_size = ucs2_utf8size(var_name); | |
239 | utf8_name = kmalloc(utf8_size + 1, GFP_KERNEL); | |
240 | if (!utf8_name) | |
241 | return false; | |
242 | ||
243 | ucs2_as_utf8(utf8_name, var_name, utf8_size); | |
244 | utf8_name[utf8_size] = '\0'; | |
fec6c20b | 245 | |
d591b6da | 246 | for (i = 0; variable_validate[i].name[0] != '\0'; i++) { |
fec6c20b | 247 | const char *name = variable_validate[i].name; |
d591b6da PJ |
248 | int match = 0; |
249 | ||
250 | if (efi_guidcmp(vendor, variable_validate[i].vendor)) | |
251 | continue; | |
fec6c20b | 252 | |
7b35014c PJ |
253 | if (variable_matches(utf8_name, utf8_size+1, name, &match)) { |
254 | if (variable_validate[i].validate == NULL) | |
fec6c20b | 255 | break; |
7b35014c PJ |
256 | kfree(utf8_name); |
257 | return variable_validate[i].validate(var_name, match, | |
258 | data, data_size); | |
fec6c20b MG |
259 | } |
260 | } | |
44f21ed1 | 261 | kfree(utf8_name); |
fec6c20b MG |
262 | return true; |
263 | } | |
e14ab23d | 264 | EXPORT_SYMBOL_GPL(efivar_validate); |
fec6c20b | 265 | |
7b35014c PJ |
266 | bool |
267 | efivar_variable_is_removable(efi_guid_t vendor, const char *var_name, | |
268 | size_t len) | |
269 | { | |
270 | int i; | |
271 | bool found = false; | |
272 | int match = 0; | |
273 | ||
274 | /* | |
275 | * Check if our variable is in the validated variables list | |
276 | */ | |
277 | for (i = 0; variable_validate[i].name[0] != '\0'; i++) { | |
278 | if (efi_guidcmp(variable_validate[i].vendor, vendor)) | |
279 | continue; | |
280 | ||
281 | if (variable_matches(var_name, len, | |
282 | variable_validate[i].name, &match)) { | |
283 | found = true; | |
284 | break; | |
285 | } | |
286 | } | |
287 | ||
288 | /* | |
289 | * If it's in our list, it is removable. | |
290 | */ | |
291 | return found; | |
292 | } | |
293 | EXPORT_SYMBOL_GPL(efivar_variable_is_removable); | |
294 | ||
1da177e4 | 295 | static efi_status_t |
e14ab23d | 296 | check_var_size(u32 attributes, unsigned long size) |
68d92986 | 297 | { |
e14ab23d | 298 | const struct efivar_operations *fops = __efivars->ops; |
68d92986 | 299 | |
a614e192 | 300 | if (!fops->query_variable_store) |
68d92986 MG |
301 | return EFI_UNSUPPORTED; |
302 | ||
a614e192 | 303 | return fops->query_variable_store(attributes, size); |
68d92986 MG |
304 | } |
305 | ||
7253eaba MF |
306 | static int efi_status_to_err(efi_status_t status) |
307 | { | |
308 | int err; | |
309 | ||
310 | switch (status) { | |
e14ab23d MF |
311 | case EFI_SUCCESS: |
312 | err = 0; | |
313 | break; | |
7253eaba MF |
314 | case EFI_INVALID_PARAMETER: |
315 | err = -EINVAL; | |
316 | break; | |
317 | case EFI_OUT_OF_RESOURCES: | |
318 | err = -ENOSPC; | |
319 | break; | |
320 | case EFI_DEVICE_ERROR: | |
321 | err = -EIO; | |
322 | break; | |
323 | case EFI_WRITE_PROTECTED: | |
324 | err = -EROFS; | |
325 | break; | |
326 | case EFI_SECURITY_VIOLATION: | |
327 | err = -EACCES; | |
328 | break; | |
329 | case EFI_NOT_FOUND: | |
e14ab23d | 330 | err = -ENOENT; |
7253eaba MF |
331 | break; |
332 | default: | |
333 | err = -EINVAL; | |
334 | } | |
335 | ||
336 | return err; | |
337 | } | |
338 | ||
e14ab23d MF |
339 | static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor, |
340 | struct list_head *head) | |
a93bc0c6 SA |
341 | { |
342 | struct efivar_entry *entry, *n; | |
a93bc0c6 SA |
343 | unsigned long strsize1, strsize2; |
344 | bool found = false; | |
345 | ||
a614e192 | 346 | strsize1 = ucs2_strsize(variable_name, 1024); |
e14ab23d | 347 | list_for_each_entry_safe(entry, n, head, list) { |
a614e192 | 348 | strsize2 = ucs2_strsize(entry->var.VariableName, 1024); |
a93bc0c6 SA |
349 | if (strsize1 == strsize2 && |
350 | !memcmp(variable_name, &(entry->var.VariableName), | |
351 | strsize2) && | |
352 | !efi_guidcmp(entry->var.VendorGuid, | |
353 | *vendor)) { | |
354 | found = true; | |
355 | break; | |
356 | } | |
357 | } | |
358 | return found; | |
359 | } | |
360 | ||
ec50bd32 MF |
361 | /* |
362 | * Returns the size of variable_name, in bytes, including the | |
363 | * terminating NULL character, or variable_name_size if no NULL | |
364 | * character is found among the first variable_name_size bytes. | |
365 | */ | |
366 | static unsigned long var_name_strnsize(efi_char16_t *variable_name, | |
367 | unsigned long variable_name_size) | |
368 | { | |
369 | unsigned long len; | |
370 | efi_char16_t c; | |
371 | ||
372 | /* | |
373 | * The variable name is, by definition, a NULL-terminated | |
374 | * string, so make absolutely sure that variable_name_size is | |
375 | * the value we expect it to be. If not, return the real size. | |
376 | */ | |
377 | for (len = 2; len <= variable_name_size; len += sizeof(c)) { | |
378 | c = variable_name[(len / sizeof(c)) - 1]; | |
379 | if (!c) | |
380 | break; | |
381 | } | |
382 | ||
383 | return min(len, variable_name_size); | |
384 | } | |
385 | ||
e971318b MF |
386 | /* |
387 | * Print a warning when duplicate EFI variables are encountered and | |
388 | * disable the sysfs workqueue since the firmware is buggy. | |
389 | */ | |
390 | static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, | |
391 | unsigned long len16) | |
392 | { | |
393 | size_t i, len8 = len16 / sizeof(efi_char16_t); | |
394 | char *s8; | |
395 | ||
396 | /* | |
397 | * Disable the workqueue since the algorithm it uses for | |
398 | * detecting new variables won't work with this buggy | |
399 | * implementation of GetNextVariableName(). | |
400 | */ | |
401 | efivar_wq_enabled = false; | |
402 | ||
403 | s8 = kzalloc(len8, GFP_KERNEL); | |
404 | if (!s8) | |
405 | return; | |
406 | ||
407 | for (i = 0; i < len8; i++) | |
408 | s8[i] = s16[i]; | |
409 | ||
410 | printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", | |
411 | s8, vendor_guid); | |
412 | kfree(s8); | |
413 | } | |
414 | ||
e14ab23d MF |
415 | /** |
416 | * efivar_init - build the initial list of EFI variables | |
417 | * @func: callback function to invoke for every variable | |
418 | * @data: function-specific data to pass to @func | |
419 | * @atomic: do we need to execute the @func-loop atomically? | |
420 | * @duplicates: error if we encounter duplicates on @head? | |
421 | * @head: initialised head of variable list | |
422 | * | |
423 | * Get every EFI variable from the firmware and invoke @func. @func | |
424 | * should call efivar_entry_add() to build the list of variables. | |
425 | * | |
426 | * Returns 0 on success, or a kernel error code on failure. | |
427 | */ | |
428 | int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *), | |
429 | void *data, bool atomic, bool duplicates, | |
430 | struct list_head *head) | |
431 | { | |
432 | const struct efivar_operations *ops = __efivars->ops; | |
433 | unsigned long variable_name_size = 1024; | |
434 | efi_char16_t *variable_name; | |
435 | efi_status_t status; | |
436 | efi_guid_t vendor_guid; | |
437 | int err = 0; | |
438 | ||
439 | variable_name = kzalloc(variable_name_size, GFP_KERNEL); | |
440 | if (!variable_name) { | |
441 | printk(KERN_ERR "efivars: Memory allocation failed.\n"); | |
442 | return -ENOMEM; | |
605e70c7 LCY |
443 | } |
444 | ||
e14ab23d MF |
445 | spin_lock_irq(&__efivars->lock); |
446 | ||
1da177e4 LT |
447 | /* |
448 | * Per EFI spec, the maximum storage allocated for both | |
449 | * the variable name and variable data is 1024 bytes. | |
450 | */ | |
451 | ||
452 | do { | |
453 | variable_name_size = 1024; | |
454 | ||
3295814d | 455 | status = ops->get_next_variable(&variable_name_size, |
1da177e4 LT |
456 | variable_name, |
457 | &vendor_guid); | |
458 | switch (status) { | |
459 | case EFI_SUCCESS: | |
e14ab23d MF |
460 | if (!atomic) |
461 | spin_unlock_irq(&__efivars->lock); | |
462 | ||
ec50bd32 MF |
463 | variable_name_size = var_name_strnsize(variable_name, |
464 | variable_name_size); | |
e971318b MF |
465 | |
466 | /* | |
467 | * Some firmware implementations return the | |
468 | * same variable name on multiple calls to | |
469 | * get_next_variable(). Terminate the loop | |
470 | * immediately as there is no guarantee that | |
471 | * we'll ever see a different variable name, | |
472 | * and may end up looping here forever. | |
473 | */ | |
e14ab23d MF |
474 | if (duplicates && |
475 | variable_is_present(variable_name, &vendor_guid, head)) { | |
e971318b MF |
476 | dup_variable_bug(variable_name, &vendor_guid, |
477 | variable_name_size); | |
e14ab23d MF |
478 | if (!atomic) |
479 | spin_lock_irq(&__efivars->lock); | |
480 | ||
e971318b MF |
481 | status = EFI_NOT_FOUND; |
482 | break; | |
483 | } | |
484 | ||
e14ab23d MF |
485 | err = func(variable_name, vendor_guid, variable_name_size, data); |
486 | if (err) | |
487 | status = EFI_NOT_FOUND; | |
488 | ||
489 | if (!atomic) | |
490 | spin_lock_irq(&__efivars->lock); | |
491 | ||
1da177e4 LT |
492 | break; |
493 | case EFI_NOT_FOUND: | |
494 | break; | |
495 | default: | |
496 | printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", | |
497 | status); | |
498 | status = EFI_NOT_FOUND; | |
499 | break; | |
500 | } | |
e14ab23d | 501 | |
1da177e4 LT |
502 | } while (status != EFI_NOT_FOUND); |
503 | ||
e14ab23d MF |
504 | spin_unlock_irq(&__efivars->lock); |
505 | ||
506 | kfree(variable_name); | |
507 | ||
508 | return err; | |
509 | } | |
510 | EXPORT_SYMBOL_GPL(efivar_init); | |
511 | ||
512 | /** | |
513 | * efivar_entry_add - add entry to variable list | |
514 | * @entry: entry to add to list | |
515 | * @head: list head | |
516 | */ | |
517 | void efivar_entry_add(struct efivar_entry *entry, struct list_head *head) | |
518 | { | |
519 | spin_lock_irq(&__efivars->lock); | |
520 | list_add(&entry->list, head); | |
521 | spin_unlock_irq(&__efivars->lock); | |
522 | } | |
523 | EXPORT_SYMBOL_GPL(efivar_entry_add); | |
524 | ||
525 | /** | |
526 | * efivar_entry_remove - remove entry from variable list | |
527 | * @entry: entry to remove from list | |
528 | */ | |
529 | void efivar_entry_remove(struct efivar_entry *entry) | |
530 | { | |
531 | spin_lock_irq(&__efivars->lock); | |
532 | list_del(&entry->list); | |
533 | spin_unlock_irq(&__efivars->lock); | |
534 | } | |
535 | EXPORT_SYMBOL_GPL(efivar_entry_remove); | |
536 | ||
537 | /* | |
538 | * efivar_entry_list_del_unlock - remove entry from variable list | |
539 | * @entry: entry to remove | |
540 | * | |
541 | * Remove @entry from the variable list and release the list lock. | |
542 | * | |
543 | * NOTE: slightly weird locking semantics here - we expect to be | |
544 | * called with the efivars lock already held, and we release it before | |
545 | * returning. This is because this function is usually called after | |
546 | * set_variable() while the lock is still held. | |
547 | */ | |
548 | static void efivar_entry_list_del_unlock(struct efivar_entry *entry) | |
549 | { | |
79943632 | 550 | lockdep_assert_held(&__efivars->lock); |
e14ab23d MF |
551 | |
552 | list_del(&entry->list); | |
553 | spin_unlock_irq(&__efivars->lock); | |
554 | } | |
555 | ||
556 | /** | |
557 | * __efivar_entry_delete - delete an EFI variable | |
558 | * @entry: entry containing EFI variable to delete | |
559 | * | |
a9499fa7 TG |
560 | * Delete the variable from the firmware but leave @entry on the |
561 | * variable list. | |
e14ab23d | 562 | * |
a9499fa7 TG |
563 | * This function differs from efivar_entry_delete() because it does |
564 | * not remove @entry from the variable list. Also, it is safe to be | |
565 | * called from within a efivar_entry_iter_begin() and | |
e14ab23d MF |
566 | * efivar_entry_iter_end() region, unlike efivar_entry_delete(). |
567 | * | |
568 | * Returns 0 on success, or a converted EFI status code if | |
a9499fa7 | 569 | * set_variable() fails. |
e14ab23d MF |
570 | */ |
571 | int __efivar_entry_delete(struct efivar_entry *entry) | |
572 | { | |
573 | const struct efivar_operations *ops = __efivars->ops; | |
574 | efi_status_t status; | |
575 | ||
79943632 | 576 | lockdep_assert_held(&__efivars->lock); |
e14ab23d MF |
577 | |
578 | status = ops->set_variable(entry->var.VariableName, | |
579 | &entry->var.VendorGuid, | |
580 | 0, 0, NULL); | |
e14ab23d | 581 | |
a9499fa7 | 582 | return efi_status_to_err(status); |
e14ab23d MF |
583 | } |
584 | EXPORT_SYMBOL_GPL(__efivar_entry_delete); | |
585 | ||
586 | /** | |
587 | * efivar_entry_delete - delete variable and remove entry from list | |
588 | * @entry: entry containing variable to delete | |
589 | * | |
590 | * Delete the variable from the firmware and remove @entry from the | |
591 | * variable list. It is the caller's responsibility to free @entry | |
592 | * once we return. | |
593 | * | |
594 | * Returns 0 on success, or a converted EFI status code if | |
595 | * set_variable() fails. | |
596 | */ | |
597 | int efivar_entry_delete(struct efivar_entry *entry) | |
598 | { | |
599 | const struct efivar_operations *ops = __efivars->ops; | |
600 | efi_status_t status; | |
601 | ||
602 | spin_lock_irq(&__efivars->lock); | |
603 | status = ops->set_variable(entry->var.VariableName, | |
604 | &entry->var.VendorGuid, | |
605 | 0, 0, NULL); | |
606 | if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) { | |
607 | spin_unlock_irq(&__efivars->lock); | |
608 | return efi_status_to_err(status); | |
609 | } | |
610 | ||
611 | efivar_entry_list_del_unlock(entry); | |
612 | return 0; | |
613 | } | |
614 | EXPORT_SYMBOL_GPL(efivar_entry_delete); | |
615 | ||
616 | /** | |
617 | * efivar_entry_set - call set_variable() | |
618 | * @entry: entry containing the EFI variable to write | |
619 | * @attributes: variable attributes | |
620 | * @size: size of @data buffer | |
621 | * @data: buffer containing variable data | |
622 | * @head: head of variable list | |
623 | * | |
624 | * Calls set_variable() for an EFI variable. If creating a new EFI | |
625 | * variable, this function is usually followed by efivar_entry_add(). | |
626 | * | |
627 | * Before writing the variable, the remaining EFI variable storage | |
628 | * space is checked to ensure there is enough room available. | |
629 | * | |
630 | * If @head is not NULL a lookup is performed to determine whether | |
631 | * the entry is already on the list. | |
632 | * | |
633 | * Returns 0 on success, -EEXIST if a lookup is performed and the entry | |
634 | * already exists on the list, or a converted EFI status code if | |
635 | * set_variable() fails. | |
636 | */ | |
637 | int efivar_entry_set(struct efivar_entry *entry, u32 attributes, | |
638 | unsigned long size, void *data, struct list_head *head) | |
639 | { | |
640 | const struct efivar_operations *ops = __efivars->ops; | |
641 | efi_status_t status; | |
642 | efi_char16_t *name = entry->var.VariableName; | |
643 | efi_guid_t vendor = entry->var.VendorGuid; | |
644 | ||
645 | spin_lock_irq(&__efivars->lock); | |
646 | ||
647 | if (head && efivar_entry_find(name, vendor, head, false)) { | |
648 | spin_unlock_irq(&__efivars->lock); | |
649 | return -EEXIST; | |
650 | } | |
651 | ||
a614e192 | 652 | status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
653 | if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) |
654 | status = ops->set_variable(name, &vendor, | |
655 | attributes, size, data); | |
656 | ||
657 | spin_unlock_irq(&__efivars->lock); | |
658 | ||
659 | return efi_status_to_err(status); | |
a9499fa7 | 660 | |
e14ab23d MF |
661 | } |
662 | EXPORT_SYMBOL_GPL(efivar_entry_set); | |
663 | ||
664 | /** | |
665 | * efivar_entry_set_safe - call set_variable() if enough space in firmware | |
666 | * @name: buffer containing the variable name | |
667 | * @vendor: variable vendor guid | |
668 | * @attributes: variable attributes | |
669 | * @block: can we block in this context? | |
670 | * @size: size of @data buffer | |
671 | * @data: buffer containing variable data | |
672 | * | |
673 | * Ensures there is enough free storage in the firmware for this variable, and | |
674 | * if so, calls set_variable(). If creating a new EFI variable, this function | |
675 | * is usually followed by efivar_entry_add(). | |
676 | * | |
677 | * Returns 0 on success, -ENOSPC if the firmware does not have enough | |
678 | * space for set_variable() to succeed, or a converted EFI status code | |
679 | * if set_variable() fails. | |
680 | */ | |
681 | int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes, | |
682 | bool block, unsigned long size, void *data) | |
683 | { | |
684 | const struct efivar_operations *ops = __efivars->ops; | |
685 | unsigned long flags; | |
686 | efi_status_t status; | |
687 | ||
a614e192 | 688 | if (!ops->query_variable_store) |
e14ab23d MF |
689 | return -ENOSYS; |
690 | ||
85c90716 DC |
691 | if (!block) { |
692 | if (!spin_trylock_irqsave(&__efivars->lock, flags)) | |
693 | return -EBUSY; | |
694 | } else { | |
e14ab23d | 695 | spin_lock_irqsave(&__efivars->lock, flags); |
85c90716 | 696 | } |
e14ab23d | 697 | |
a614e192 | 698 | status = check_var_size(attributes, size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
699 | if (status != EFI_SUCCESS) { |
700 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
701 | return -ENOSPC; | |
702 | } | |
703 | ||
704 | status = ops->set_variable(name, &vendor, attributes, size, data); | |
705 | ||
706 | spin_unlock_irqrestore(&__efivars->lock, flags); | |
707 | ||
708 | return efi_status_to_err(status); | |
709 | } | |
710 | EXPORT_SYMBOL_GPL(efivar_entry_set_safe); | |
711 | ||
712 | /** | |
713 | * efivar_entry_find - search for an entry | |
714 | * @name: the EFI variable name | |
715 | * @guid: the EFI variable vendor's guid | |
716 | * @head: head of the variable list | |
717 | * @remove: should we remove the entry from the list? | |
718 | * | |
719 | * Search for an entry on the variable list that has the EFI variable | |
720 | * name @name and vendor guid @guid. If an entry is found on the list | |
721 | * and @remove is true, the entry is removed from the list. | |
722 | * | |
723 | * The caller MUST call efivar_entry_iter_begin() and | |
724 | * efivar_entry_iter_end() before and after the invocation of this | |
725 | * function, respectively. | |
726 | * | |
727 | * Returns the entry if found on the list, %NULL otherwise. | |
728 | */ | |
729 | struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid, | |
730 | struct list_head *head, bool remove) | |
731 | { | |
732 | struct efivar_entry *entry, *n; | |
733 | int strsize1, strsize2; | |
734 | bool found = false; | |
735 | ||
79943632 | 736 | lockdep_assert_held(&__efivars->lock); |
e14ab23d MF |
737 | |
738 | list_for_each_entry_safe(entry, n, head, list) { | |
a614e192 MF |
739 | strsize1 = ucs2_strsize(name, 1024); |
740 | strsize2 = ucs2_strsize(entry->var.VariableName, 1024); | |
e14ab23d MF |
741 | if (strsize1 == strsize2 && |
742 | !memcmp(name, &(entry->var.VariableName), strsize1) && | |
743 | !efi_guidcmp(guid, entry->var.VendorGuid)) { | |
744 | found = true; | |
745 | break; | |
746 | } | |
747 | } | |
748 | ||
749 | if (!found) | |
750 | return NULL; | |
751 | ||
752 | if (remove) | |
753 | list_del(&entry->list); | |
754 | ||
755 | return entry; | |
756 | } | |
757 | EXPORT_SYMBOL_GPL(efivar_entry_find); | |
758 | ||
759 | /** | |
8a415b8c | 760 | * efivar_entry_size - obtain the size of a variable |
e14ab23d MF |
761 | * @entry: entry for this variable |
762 | * @size: location to store the variable's size | |
e14ab23d | 763 | */ |
8a415b8c | 764 | int efivar_entry_size(struct efivar_entry *entry, unsigned long *size) |
e14ab23d MF |
765 | { |
766 | const struct efivar_operations *ops = __efivars->ops; | |
767 | efi_status_t status; | |
768 | ||
e14ab23d | 769 | *size = 0; |
8a415b8c MF |
770 | |
771 | spin_lock_irq(&__efivars->lock); | |
e14ab23d MF |
772 | status = ops->get_variable(entry->var.VariableName, |
773 | &entry->var.VendorGuid, NULL, size, NULL); | |
8a415b8c MF |
774 | spin_unlock_irq(&__efivars->lock); |
775 | ||
e14ab23d MF |
776 | if (status != EFI_BUFFER_TOO_SMALL) |
777 | return efi_status_to_err(status); | |
778 | ||
779 | return 0; | |
780 | } | |
8a415b8c | 781 | EXPORT_SYMBOL_GPL(efivar_entry_size); |
e14ab23d MF |
782 | |
783 | /** | |
8a415b8c MF |
784 | * __efivar_entry_get - call get_variable() |
785 | * @entry: read data for this variable | |
786 | * @attributes: variable attributes | |
787 | * @size: size of @data buffer | |
788 | * @data: buffer to store variable data | |
789 | * | |
790 | * The caller MUST call efivar_entry_iter_begin() and | |
791 | * efivar_entry_iter_end() before and after the invocation of this | |
792 | * function, respectively. | |
e14ab23d | 793 | */ |
8a415b8c MF |
794 | int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes, |
795 | unsigned long *size, void *data) | |
e14ab23d MF |
796 | { |
797 | const struct efivar_operations *ops = __efivars->ops; | |
798 | efi_status_t status; | |
799 | ||
79943632 | 800 | lockdep_assert_held(&__efivars->lock); |
e14ab23d | 801 | |
e14ab23d | 802 | status = ops->get_variable(entry->var.VariableName, |
8a415b8c MF |
803 | &entry->var.VendorGuid, |
804 | attributes, size, data); | |
e14ab23d | 805 | |
8a415b8c | 806 | return efi_status_to_err(status); |
e14ab23d | 807 | } |
8a415b8c | 808 | EXPORT_SYMBOL_GPL(__efivar_entry_get); |
e14ab23d MF |
809 | |
810 | /** | |
811 | * efivar_entry_get - call get_variable() | |
812 | * @entry: read data for this variable | |
813 | * @attributes: variable attributes | |
814 | * @size: size of @data buffer | |
815 | * @data: buffer to store variable data | |
816 | */ | |
817 | int efivar_entry_get(struct efivar_entry *entry, u32 *attributes, | |
818 | unsigned long *size, void *data) | |
819 | { | |
820 | const struct efivar_operations *ops = __efivars->ops; | |
821 | efi_status_t status; | |
822 | ||
823 | spin_lock_irq(&__efivars->lock); | |
824 | status = ops->get_variable(entry->var.VariableName, | |
825 | &entry->var.VendorGuid, | |
826 | attributes, size, data); | |
827 | spin_unlock_irq(&__efivars->lock); | |
828 | ||
829 | return efi_status_to_err(status); | |
830 | } | |
831 | EXPORT_SYMBOL_GPL(efivar_entry_get); | |
832 | ||
833 | /** | |
834 | * efivar_entry_set_get_size - call set_variable() and get new size (atomic) | |
835 | * @entry: entry containing variable to set and get | |
836 | * @attributes: attributes of variable to be written | |
837 | * @size: size of data buffer | |
838 | * @data: buffer containing data to write | |
839 | * @set: did the set_variable() call succeed? | |
840 | * | |
841 | * This is a pretty special (complex) function. See efivarfs_file_write(). | |
842 | * | |
843 | * Atomically call set_variable() for @entry and if the call is | |
844 | * successful, return the new size of the variable from get_variable() | |
845 | * in @size. The success of set_variable() is indicated by @set. | |
846 | * | |
847 | * Returns 0 on success, -EINVAL if the variable data is invalid, | |
848 | * -ENOSPC if the firmware does not have enough available space, or a | |
849 | * converted EFI status code if either of set_variable() or | |
850 | * get_variable() fail. | |
851 | * | |
852 | * If the EFI variable does not exist when calling set_variable() | |
853 | * (EFI_NOT_FOUND), @entry is removed from the variable list. | |
854 | */ | |
855 | int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, | |
856 | unsigned long *size, void *data, bool *set) | |
857 | { | |
858 | const struct efivar_operations *ops = __efivars->ops; | |
859 | efi_char16_t *name = entry->var.VariableName; | |
860 | efi_guid_t *vendor = &entry->var.VendorGuid; | |
861 | efi_status_t status; | |
862 | int err; | |
863 | ||
864 | *set = false; | |
865 | ||
d591b6da | 866 | if (efivar_validate(*vendor, name, data, *size) == false) |
e14ab23d MF |
867 | return -EINVAL; |
868 | ||
869 | /* | |
870 | * The lock here protects the get_variable call, the conditional | |
871 | * set_variable call, and removal of the variable from the efivars | |
872 | * list (in the case of an authenticated delete). | |
873 | */ | |
874 | spin_lock_irq(&__efivars->lock); | |
875 | ||
876 | /* | |
877 | * Ensure that the available space hasn't shrunk below the safe level | |
878 | */ | |
a614e192 | 879 | status = check_var_size(attributes, *size + ucs2_strsize(name, 1024)); |
e14ab23d MF |
880 | if (status != EFI_SUCCESS) { |
881 | if (status != EFI_UNSUPPORTED) { | |
882 | err = efi_status_to_err(status); | |
883 | goto out; | |
884 | } | |
885 | ||
886 | if (*size > 65536) { | |
887 | err = -ENOSPC; | |
888 | goto out; | |
889 | } | |
890 | } | |
891 | ||
892 | status = ops->set_variable(name, vendor, attributes, *size, data); | |
893 | if (status != EFI_SUCCESS) { | |
894 | err = efi_status_to_err(status); | |
895 | goto out; | |
896 | } | |
897 | ||
898 | *set = true; | |
899 | ||
900 | /* | |
901 | * Writing to the variable may have caused a change in size (which | |
902 | * could either be an append or an overwrite), or the variable to be | |
903 | * deleted. Perform a GetVariable() so we can tell what actually | |
904 | * happened. | |
905 | */ | |
906 | *size = 0; | |
907 | status = ops->get_variable(entry->var.VariableName, | |
908 | &entry->var.VendorGuid, | |
909 | NULL, size, NULL); | |
910 | ||
911 | if (status == EFI_NOT_FOUND) | |
912 | efivar_entry_list_del_unlock(entry); | |
913 | else | |
914 | spin_unlock_irq(&__efivars->lock); | |
915 | ||
916 | if (status && status != EFI_BUFFER_TOO_SMALL) | |
917 | return efi_status_to_err(status); | |
918 | ||
919 | return 0; | |
920 | ||
921 | out: | |
922 | spin_unlock_irq(&__efivars->lock); | |
923 | return err; | |
924 | ||
925 | } | |
926 | EXPORT_SYMBOL_GPL(efivar_entry_set_get_size); | |
927 | ||
928 | /** | |
929 | * efivar_entry_iter_begin - begin iterating the variable list | |
930 | * | |
931 | * Lock the variable list to prevent entry insertion and removal until | |
932 | * efivar_entry_iter_end() is called. This function is usually used in | |
933 | * conjunction with __efivar_entry_iter() or efivar_entry_iter(). | |
934 | */ | |
935 | void efivar_entry_iter_begin(void) | |
936 | { | |
937 | spin_lock_irq(&__efivars->lock); | |
938 | } | |
939 | EXPORT_SYMBOL_GPL(efivar_entry_iter_begin); | |
940 | ||
941 | /** | |
942 | * efivar_entry_iter_end - finish iterating the variable list | |
943 | * | |
944 | * Unlock the variable list and allow modifications to the list again. | |
945 | */ | |
946 | void efivar_entry_iter_end(void) | |
947 | { | |
948 | spin_unlock_irq(&__efivars->lock); | |
949 | } | |
950 | EXPORT_SYMBOL_GPL(efivar_entry_iter_end); | |
951 | ||
952 | /** | |
953 | * __efivar_entry_iter - iterate over variable list | |
954 | * @func: callback function | |
955 | * @head: head of the variable list | |
956 | * @data: function-specific data to pass to callback | |
957 | * @prev: entry to begin iterating from | |
958 | * | |
959 | * Iterate over the list of EFI variables and call @func with every | |
960 | * entry on the list. It is safe for @func to remove entries in the | |
961 | * list via efivar_entry_delete(). | |
962 | * | |
963 | * You MUST call efivar_enter_iter_begin() before this function, and | |
964 | * efivar_entry_iter_end() afterwards. | |
965 | * | |
966 | * It is possible to begin iteration from an arbitrary entry within | |
967 | * the list by passing @prev. @prev is updated on return to point to | |
968 | * the last entry passed to @func. To begin iterating from the | |
969 | * beginning of the list @prev must be %NULL. | |
970 | * | |
971 | * The restrictions for @func are the same as documented for | |
972 | * efivar_entry_iter(). | |
973 | */ | |
974 | int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *), | |
975 | struct list_head *head, void *data, | |
976 | struct efivar_entry **prev) | |
977 | { | |
978 | struct efivar_entry *entry, *n; | |
979 | int err = 0; | |
980 | ||
981 | if (!prev || !*prev) { | |
982 | list_for_each_entry_safe(entry, n, head, list) { | |
983 | err = func(entry, data); | |
984 | if (err) | |
985 | break; | |
986 | } | |
987 | ||
988 | if (prev) | |
989 | *prev = entry; | |
990 | ||
991 | return err; | |
992 | } | |
993 | ||
994 | ||
995 | list_for_each_entry_safe_continue((*prev), n, head, list) { | |
996 | err = func(*prev, data); | |
997 | if (err) | |
998 | break; | |
999 | } | |
1000 | ||
1001 | return err; | |
1002 | } | |
1003 | EXPORT_SYMBOL_GPL(__efivar_entry_iter); | |
1004 | ||
1005 | /** | |
1006 | * efivar_entry_iter - iterate over variable list | |
1007 | * @func: callback function | |
1008 | * @head: head of variable list | |
1009 | * @data: function-specific data to pass to callback | |
1010 | * | |
1011 | * Iterate over the list of EFI variables and call @func with every | |
1012 | * entry on the list. It is safe for @func to remove entries in the | |
1013 | * list via efivar_entry_delete() while iterating. | |
1014 | * | |
1015 | * Some notes for the callback function: | |
1016 | * - a non-zero return value indicates an error and terminates the loop | |
1017 | * - @func is called from atomic context | |
1018 | */ | |
1019 | int efivar_entry_iter(int (*func)(struct efivar_entry *, void *), | |
1020 | struct list_head *head, void *data) | |
1021 | { | |
1022 | int err = 0; | |
1023 | ||
1024 | efivar_entry_iter_begin(); | |
1025 | err = __efivar_entry_iter(func, head, data, NULL); | |
1026 | efivar_entry_iter_end(); | |
1027 | ||
1028 | return err; | |
1029 | } | |
1030 | EXPORT_SYMBOL_GPL(efivar_entry_iter); | |
1031 | ||
1032 | /** | |
1033 | * efivars_kobject - get the kobject for the registered efivars | |
1034 | * | |
1035 | * If efivars_register() has not been called we return NULL, | |
1036 | * otherwise return the kobject used at registration time. | |
1037 | */ | |
1038 | struct kobject *efivars_kobject(void) | |
1039 | { | |
1040 | if (!__efivars) | |
1041 | return NULL; | |
1042 | ||
1043 | return __efivars->kobject; | |
1044 | } | |
1045 | EXPORT_SYMBOL_GPL(efivars_kobject); | |
1046 | ||
04851772 MF |
1047 | /** |
1048 | * efivar_run_worker - schedule the efivar worker thread | |
1049 | */ | |
1050 | void efivar_run_worker(void) | |
1051 | { | |
1052 | if (efivar_wq_enabled) | |
1053 | schedule_work(&efivar_work); | |
1054 | } | |
1055 | EXPORT_SYMBOL_GPL(efivar_run_worker); | |
1056 | ||
e14ab23d MF |
1057 | /** |
1058 | * efivars_register - register an efivars | |
1059 | * @efivars: efivars to register | |
1060 | * @ops: efivars operations | |
1061 | * @kobject: @efivars-specific kobject | |
1062 | * | |
1063 | * Only a single efivars can be registered at any time. | |
1064 | */ | |
1065 | int efivars_register(struct efivars *efivars, | |
1066 | const struct efivar_operations *ops, | |
1067 | struct kobject *kobject) | |
1068 | { | |
1069 | spin_lock_init(&efivars->lock); | |
1070 | efivars->ops = ops; | |
1071 | efivars->kobject = kobject; | |
1072 | ||
1073 | __efivars = efivars; | |
1da177e4 | 1074 | |
e14ab23d MF |
1075 | return 0; |
1076 | } | |
1077 | EXPORT_SYMBOL_GPL(efivars_register); | |
1da177e4 | 1078 | |
e14ab23d MF |
1079 | /** |
1080 | * efivars_unregister - unregister an efivars | |
1081 | * @efivars: efivars to unregister | |
1082 | * | |
1083 | * The caller must have already removed every entry from the list, | |
1084 | * failure to do so is an error. | |
1085 | */ | |
1086 | int efivars_unregister(struct efivars *efivars) | |
1087 | { | |
1088 | int rv; | |
1089 | ||
1090 | if (!__efivars) { | |
1091 | printk(KERN_ERR "efivars not registered\n"); | |
1092 | rv = -EINVAL; | |
1093 | goto out; | |
1094 | } | |
1095 | ||
1096 | if (__efivars != efivars) { | |
1097 | rv = -EINVAL; | |
1098 | goto out; | |
1099 | } | |
1100 | ||
1101 | __efivars = NULL; | |
1102 | ||
1103 | rv = 0; | |
1104 | out: | |
1105 | return rv; | |
76b53f7c | 1106 | } |
e14ab23d | 1107 | EXPORT_SYMBOL_GPL(efivars_unregister); |