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a9499fa7 TG |
1 | /* |
2 | * Originally from efivars.c, | |
3 | * | |
4 | * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com> | |
5 | * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com> | |
6 | * | |
7 | * This code takes all variables accessible from EFI runtime and | |
8 | * exports them via sysfs | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License as published by | |
12 | * the Free Software Foundation; either version 2 of the License, or | |
13 | * (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | * GNU General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
23 | * | |
24 | * Changelog: | |
25 | * | |
26 | * 17 May 2004 - Matt Domsch <Matt_Domsch@dell.com> | |
27 | * remove check for efi_enabled in exit | |
28 | * add MODULE_VERSION | |
29 | * | |
30 | * 26 Apr 2004 - Matt Domsch <Matt_Domsch@dell.com> | |
31 | * minor bug fixes | |
32 | * | |
33 | * 21 Apr 2004 - Matt Tolentino <matthew.e.tolentino@intel.com) | |
34 | * converted driver to export variable information via sysfs | |
35 | * and moved to drivers/firmware directory | |
36 | * bumped revision number to v0.07 to reflect conversion & move | |
37 | * | |
38 | * 10 Dec 2002 - Matt Domsch <Matt_Domsch@dell.com> | |
39 | * fix locking per Peter Chubb's findings | |
40 | * | |
41 | * 25 Mar 2002 - Matt Domsch <Matt_Domsch@dell.com> | |
26e02272 | 42 | * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_to_str() |
a9499fa7 TG |
43 | * |
44 | * 12 Feb 2002 - Matt Domsch <Matt_Domsch@dell.com> | |
45 | * use list_for_each_safe when deleting vars. | |
46 | * remove ifdef CONFIG_SMP around include <linux/smp.h> | |
47 | * v0.04 release to linux-ia64@linuxia64.org | |
48 | * | |
49 | * 20 April 2001 - Matt Domsch <Matt_Domsch@dell.com> | |
50 | * Moved vars from /proc/efi to /proc/efi/vars, and made | |
51 | * efi.c own the /proc/efi directory. | |
52 | * v0.03 release to linux-ia64@linuxia64.org | |
53 | * | |
54 | * 26 March 2001 - Matt Domsch <Matt_Domsch@dell.com> | |
55 | * At the request of Stephane, moved ownership of /proc/efi | |
56 | * to efi.c, and now efivars lives under /proc/efi/vars. | |
57 | * | |
58 | * 12 March 2001 - Matt Domsch <Matt_Domsch@dell.com> | |
59 | * Feedback received from Stephane Eranian incorporated. | |
60 | * efivar_write() checks copy_from_user() return value. | |
61 | * efivar_read/write() returns proper errno. | |
62 | * v0.02 release to linux-ia64@linuxia64.org | |
63 | * | |
64 | * 26 February 2001 - Matt Domsch <Matt_Domsch@dell.com> | |
65 | * v0.01 release to linux-ia64@linuxia64.org | |
66 | */ | |
67 | ||
68 | #include <linux/efi.h> | |
69 | #include <linux/module.h> | |
20b4fb48 | 70 | #include <linux/slab.h> |
a614e192 | 71 | #include <linux/ucs2_string.h> |
e33655a3 | 72 | #include <linux/compat.h> |
a9499fa7 TG |
73 | |
74 | #define EFIVARS_VERSION "0.08" | |
75 | #define EFIVARS_DATE "2004-May-17" | |
76 | ||
77 | MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>"); | |
78 | MODULE_DESCRIPTION("sysfs interface to EFI Variables"); | |
79 | MODULE_LICENSE("GPL"); | |
80 | MODULE_VERSION(EFIVARS_VERSION); | |
28d54022 | 81 | MODULE_ALIAS("platform:efivars"); |
a9499fa7 TG |
82 | |
83 | LIST_HEAD(efivar_sysfs_list); | |
84 | EXPORT_SYMBOL_GPL(efivar_sysfs_list); | |
85 | ||
86 | static struct kset *efivars_kset; | |
87 | ||
88 | static struct bin_attribute *efivars_new_var; | |
89 | static struct bin_attribute *efivars_del_var; | |
90 | ||
e33655a3 MF |
91 | struct compat_efi_variable { |
92 | efi_char16_t VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)]; | |
93 | efi_guid_t VendorGuid; | |
94 | __u32 DataSize; | |
95 | __u8 Data[1024]; | |
96 | __u32 Status; | |
97 | __u32 Attributes; | |
98 | } __packed; | |
99 | ||
a9499fa7 TG |
100 | struct efivar_attribute { |
101 | struct attribute attr; | |
102 | ssize_t (*show) (struct efivar_entry *entry, char *buf); | |
103 | ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); | |
104 | }; | |
105 | ||
106 | #define EFIVAR_ATTR(_name, _mode, _show, _store) \ | |
107 | struct efivar_attribute efivar_attr_##_name = { \ | |
108 | .attr = {.name = __stringify(_name), .mode = _mode}, \ | |
109 | .show = _show, \ | |
110 | .store = _store, \ | |
111 | }; | |
112 | ||
113 | #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr) | |
114 | #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj) | |
115 | ||
116 | /* | |
117 | * Prototype for sysfs creation function | |
118 | */ | |
119 | static int | |
120 | efivar_create_sysfs_entry(struct efivar_entry *new_var); | |
121 | ||
122 | static ssize_t | |
123 | efivar_guid_read(struct efivar_entry *entry, char *buf) | |
124 | { | |
125 | struct efi_variable *var = &entry->var; | |
126 | char *str = buf; | |
127 | ||
128 | if (!entry || !buf) | |
129 | return 0; | |
130 | ||
26e02272 | 131 | efi_guid_to_str(&var->VendorGuid, str); |
a9499fa7 TG |
132 | str += strlen(str); |
133 | str += sprintf(str, "\n"); | |
134 | ||
135 | return str - buf; | |
136 | } | |
137 | ||
138 | static ssize_t | |
139 | efivar_attr_read(struct efivar_entry *entry, char *buf) | |
140 | { | |
141 | struct efi_variable *var = &entry->var; | |
142 | char *str = buf; | |
143 | ||
144 | if (!entry || !buf) | |
145 | return -EINVAL; | |
146 | ||
147 | var->DataSize = 1024; | |
148 | if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) | |
149 | return -EIO; | |
150 | ||
151 | if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) | |
152 | str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n"); | |
153 | if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) | |
154 | str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n"); | |
155 | if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) | |
156 | str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n"); | |
157 | if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) | |
158 | str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n"); | |
159 | if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) | |
160 | str += sprintf(str, | |
161 | "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n"); | |
162 | if (var->Attributes & | |
163 | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) | |
164 | str += sprintf(str, | |
165 | "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n"); | |
166 | if (var->Attributes & EFI_VARIABLE_APPEND_WRITE) | |
167 | str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n"); | |
168 | return str - buf; | |
169 | } | |
170 | ||
171 | static ssize_t | |
172 | efivar_size_read(struct efivar_entry *entry, char *buf) | |
173 | { | |
174 | struct efi_variable *var = &entry->var; | |
175 | char *str = buf; | |
176 | ||
177 | if (!entry || !buf) | |
178 | return -EINVAL; | |
179 | ||
180 | var->DataSize = 1024; | |
181 | if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) | |
182 | return -EIO; | |
183 | ||
184 | str += sprintf(str, "0x%lx\n", var->DataSize); | |
185 | return str - buf; | |
186 | } | |
187 | ||
188 | static ssize_t | |
189 | efivar_data_read(struct efivar_entry *entry, char *buf) | |
190 | { | |
191 | struct efi_variable *var = &entry->var; | |
192 | ||
193 | if (!entry || !buf) | |
194 | return -EINVAL; | |
195 | ||
196 | var->DataSize = 1024; | |
197 | if (efivar_entry_get(entry, &var->Attributes, &var->DataSize, var->Data)) | |
198 | return -EIO; | |
199 | ||
200 | memcpy(buf, var->Data, var->DataSize); | |
201 | return var->DataSize; | |
202 | } | |
54d2fbfb MF |
203 | |
204 | static inline int | |
205 | sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor, | |
206 | unsigned long size, u32 attributes, u8 *data) | |
207 | { | |
208 | /* | |
209 | * If only updating the variable data, then the name | |
210 | * and guid should remain the same | |
211 | */ | |
212 | if (memcmp(name, var->VariableName, sizeof(var->VariableName)) || | |
213 | efi_guidcmp(vendor, var->VendorGuid)) { | |
214 | printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); | |
215 | return -EINVAL; | |
216 | } | |
217 | ||
218 | if ((size <= 0) || (attributes == 0)){ | |
219 | printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); | |
220 | return -EINVAL; | |
221 | } | |
222 | ||
223 | if ((attributes & ~EFI_VARIABLE_MASK) != 0 || | |
8282f5d9 | 224 | efivar_validate(vendor, name, data, size) == false) { |
54d2fbfb MF |
225 | printk(KERN_ERR "efivars: Malformed variable content\n"); |
226 | return -EINVAL; | |
227 | } | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
e33655a3 MF |
232 | static inline bool is_compat(void) |
233 | { | |
4f01ed22 | 234 | if (IS_ENABLED(CONFIG_COMPAT) && in_compat_syscall()) |
e33655a3 MF |
235 | return true; |
236 | ||
237 | return false; | |
238 | } | |
239 | ||
240 | static void | |
241 | copy_out_compat(struct efi_variable *dst, struct compat_efi_variable *src) | |
242 | { | |
243 | memcpy(dst->VariableName, src->VariableName, EFI_VAR_NAME_LEN); | |
244 | memcpy(dst->Data, src->Data, sizeof(src->Data)); | |
245 | ||
246 | dst->VendorGuid = src->VendorGuid; | |
247 | dst->DataSize = src->DataSize; | |
248 | dst->Attributes = src->Attributes; | |
249 | } | |
250 | ||
a9499fa7 TG |
251 | /* |
252 | * We allow each variable to be edited via rewriting the | |
253 | * entire efi variable structure. | |
254 | */ | |
255 | static ssize_t | |
256 | efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) | |
257 | { | |
258 | struct efi_variable *new_var, *var = &entry->var; | |
bafc84d5 MF |
259 | efi_char16_t *name; |
260 | unsigned long size; | |
261 | efi_guid_t vendor; | |
262 | u32 attributes; | |
263 | u8 *data; | |
a9499fa7 TG |
264 | int err; |
265 | ||
e33655a3 MF |
266 | if (is_compat()) { |
267 | struct compat_efi_variable *compat; | |
a9499fa7 | 268 | |
e33655a3 MF |
269 | if (count != sizeof(*compat)) |
270 | return -EINVAL; | |
bafc84d5 | 271 | |
e33655a3 MF |
272 | compat = (struct compat_efi_variable *)buf; |
273 | attributes = compat->Attributes; | |
274 | vendor = compat->VendorGuid; | |
275 | name = compat->VariableName; | |
276 | size = compat->DataSize; | |
277 | data = compat->Data; | |
bafc84d5 | 278 | |
e33655a3 MF |
279 | err = sanity_check(var, name, vendor, size, attributes, data); |
280 | if (err) | |
281 | return err; | |
282 | ||
283 | copy_out_compat(&entry->var, compat); | |
284 | } else { | |
285 | if (count != sizeof(struct efi_variable)) | |
286 | return -EINVAL; | |
287 | ||
288 | new_var = (struct efi_variable *)buf; | |
a9499fa7 | 289 | |
e33655a3 MF |
290 | attributes = new_var->Attributes; |
291 | vendor = new_var->VendorGuid; | |
292 | name = new_var->VariableName; | |
293 | size = new_var->DataSize; | |
294 | data = new_var->Data; | |
295 | ||
296 | err = sanity_check(var, name, vendor, size, attributes, data); | |
297 | if (err) | |
298 | return err; | |
299 | ||
300 | memcpy(&entry->var, new_var, count); | |
301 | } | |
a9499fa7 | 302 | |
bafc84d5 | 303 | err = efivar_entry_set(entry, attributes, size, data, NULL); |
a9499fa7 TG |
304 | if (err) { |
305 | printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err); | |
306 | return -EIO; | |
307 | } | |
308 | ||
309 | return count; | |
310 | } | |
311 | ||
312 | static ssize_t | |
313 | efivar_show_raw(struct efivar_entry *entry, char *buf) | |
314 | { | |
315 | struct efi_variable *var = &entry->var; | |
e33655a3 MF |
316 | struct compat_efi_variable *compat; |
317 | size_t size; | |
a9499fa7 TG |
318 | |
319 | if (!entry || !buf) | |
320 | return 0; | |
321 | ||
322 | var->DataSize = 1024; | |
323 | if (efivar_entry_get(entry, &entry->var.Attributes, | |
324 | &entry->var.DataSize, entry->var.Data)) | |
325 | return -EIO; | |
326 | ||
e33655a3 MF |
327 | if (is_compat()) { |
328 | compat = (struct compat_efi_variable *)buf; | |
329 | ||
330 | size = sizeof(*compat); | |
331 | memcpy(compat->VariableName, var->VariableName, | |
332 | EFI_VAR_NAME_LEN); | |
333 | memcpy(compat->Data, var->Data, sizeof(compat->Data)); | |
334 | ||
335 | compat->VendorGuid = var->VendorGuid; | |
336 | compat->DataSize = var->DataSize; | |
337 | compat->Attributes = var->Attributes; | |
338 | } else { | |
339 | size = sizeof(*var); | |
340 | memcpy(buf, var, size); | |
341 | } | |
a9499fa7 | 342 | |
e33655a3 | 343 | return size; |
a9499fa7 TG |
344 | } |
345 | ||
346 | /* | |
347 | * Generic read/write functions that call the specific functions of | |
348 | * the attributes... | |
349 | */ | |
350 | static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr, | |
351 | char *buf) | |
352 | { | |
353 | struct efivar_entry *var = to_efivar_entry(kobj); | |
354 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); | |
355 | ssize_t ret = -EIO; | |
356 | ||
357 | if (!capable(CAP_SYS_ADMIN)) | |
358 | return -EACCES; | |
359 | ||
360 | if (efivar_attr->show) { | |
361 | ret = efivar_attr->show(var, buf); | |
362 | } | |
363 | return ret; | |
364 | } | |
365 | ||
366 | static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr, | |
367 | const char *buf, size_t count) | |
368 | { | |
369 | struct efivar_entry *var = to_efivar_entry(kobj); | |
370 | struct efivar_attribute *efivar_attr = to_efivar_attr(attr); | |
371 | ssize_t ret = -EIO; | |
372 | ||
373 | if (!capable(CAP_SYS_ADMIN)) | |
374 | return -EACCES; | |
375 | ||
376 | if (efivar_attr->store) | |
377 | ret = efivar_attr->store(var, buf, count); | |
378 | ||
379 | return ret; | |
380 | } | |
381 | ||
382 | static const struct sysfs_ops efivar_attr_ops = { | |
383 | .show = efivar_attr_show, | |
384 | .store = efivar_attr_store, | |
385 | }; | |
386 | ||
387 | static void efivar_release(struct kobject *kobj) | |
388 | { | |
9c09a342 | 389 | struct efivar_entry *var = to_efivar_entry(kobj); |
a9499fa7 TG |
390 | kfree(var); |
391 | } | |
392 | ||
393 | static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); | |
394 | static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); | |
395 | static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); | |
396 | static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); | |
397 | static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); | |
398 | ||
399 | static struct attribute *def_attrs[] = { | |
400 | &efivar_attr_guid.attr, | |
401 | &efivar_attr_size.attr, | |
402 | &efivar_attr_attributes.attr, | |
403 | &efivar_attr_data.attr, | |
404 | &efivar_attr_raw_var.attr, | |
405 | NULL, | |
406 | }; | |
407 | ||
408 | static struct kobj_type efivar_ktype = { | |
409 | .release = efivar_release, | |
410 | .sysfs_ops = &efivar_attr_ops, | |
411 | .default_attrs = def_attrs, | |
412 | }; | |
413 | ||
414 | static ssize_t efivar_create(struct file *filp, struct kobject *kobj, | |
415 | struct bin_attribute *bin_attr, | |
416 | char *buf, loff_t pos, size_t count) | |
417 | { | |
e33655a3 | 418 | struct compat_efi_variable *compat = (struct compat_efi_variable *)buf; |
a9499fa7 TG |
419 | struct efi_variable *new_var = (struct efi_variable *)buf; |
420 | struct efivar_entry *new_entry; | |
e33655a3 | 421 | bool need_compat = is_compat(); |
a5d92ad3 | 422 | efi_char16_t *name; |
bafc84d5 MF |
423 | unsigned long size; |
424 | u32 attributes; | |
425 | u8 *data; | |
a9499fa7 TG |
426 | int err; |
427 | ||
428 | if (!capable(CAP_SYS_ADMIN)) | |
429 | return -EACCES; | |
430 | ||
e33655a3 MF |
431 | if (need_compat) { |
432 | if (count != sizeof(*compat)) | |
433 | return -EINVAL; | |
434 | ||
435 | attributes = compat->Attributes; | |
436 | name = compat->VariableName; | |
437 | size = compat->DataSize; | |
438 | data = compat->Data; | |
439 | } else { | |
440 | if (count != sizeof(*new_var)) | |
441 | return -EINVAL; | |
442 | ||
443 | attributes = new_var->Attributes; | |
444 | name = new_var->VariableName; | |
445 | size = new_var->DataSize; | |
446 | data = new_var->Data; | |
447 | } | |
bafc84d5 MF |
448 | |
449 | if ((attributes & ~EFI_VARIABLE_MASK) != 0 || | |
8282f5d9 PJ |
450 | efivar_validate(new_var->VendorGuid, name, data, |
451 | size) == false) { | |
a9499fa7 TG |
452 | printk(KERN_ERR "efivars: Malformed variable content\n"); |
453 | return -EINVAL; | |
454 | } | |
455 | ||
456 | new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL); | |
457 | if (!new_entry) | |
458 | return -ENOMEM; | |
459 | ||
e33655a3 MF |
460 | if (need_compat) |
461 | copy_out_compat(&new_entry->var, compat); | |
462 | else | |
463 | memcpy(&new_entry->var, new_var, sizeof(*new_var)); | |
a9499fa7 | 464 | |
bafc84d5 MF |
465 | err = efivar_entry_set(new_entry, attributes, size, |
466 | data, &efivar_sysfs_list); | |
a9499fa7 TG |
467 | if (err) { |
468 | if (err == -EEXIST) | |
469 | err = -EINVAL; | |
470 | goto out; | |
471 | } | |
472 | ||
473 | if (efivar_create_sysfs_entry(new_entry)) { | |
474 | printk(KERN_WARNING "efivars: failed to create sysfs entry.\n"); | |
475 | kfree(new_entry); | |
476 | } | |
477 | return count; | |
478 | ||
479 | out: | |
480 | kfree(new_entry); | |
481 | return err; | |
482 | } | |
483 | ||
484 | static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, | |
485 | struct bin_attribute *bin_attr, | |
486 | char *buf, loff_t pos, size_t count) | |
487 | { | |
488 | struct efi_variable *del_var = (struct efi_variable *)buf; | |
e33655a3 | 489 | struct compat_efi_variable *compat; |
a9499fa7 | 490 | struct efivar_entry *entry; |
bafc84d5 MF |
491 | efi_char16_t *name; |
492 | efi_guid_t vendor; | |
a9499fa7 TG |
493 | int err = 0; |
494 | ||
495 | if (!capable(CAP_SYS_ADMIN)) | |
496 | return -EACCES; | |
497 | ||
e33655a3 MF |
498 | if (is_compat()) { |
499 | if (count != sizeof(*compat)) | |
500 | return -EINVAL; | |
501 | ||
502 | compat = (struct compat_efi_variable *)buf; | |
503 | name = compat->VariableName; | |
504 | vendor = compat->VendorGuid; | |
505 | } else { | |
506 | if (count != sizeof(*del_var)) | |
507 | return -EINVAL; | |
e003bbee | 508 | |
e33655a3 MF |
509 | name = del_var->VariableName; |
510 | vendor = del_var->VendorGuid; | |
511 | } | |
bafc84d5 | 512 | |
21b3ddd3 SC |
513 | if (efivar_entry_iter_begin()) |
514 | return -EINTR; | |
bafc84d5 | 515 | entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true); |
a9499fa7 TG |
516 | if (!entry) |
517 | err = -EINVAL; | |
518 | else if (__efivar_entry_delete(entry)) | |
519 | err = -EIO; | |
520 | ||
e0d59733 SA |
521 | if (err) { |
522 | efivar_entry_iter_end(); | |
a9499fa7 | 523 | return err; |
e0d59733 | 524 | } |
a9499fa7 | 525 | |
e0d59733 SA |
526 | if (!entry->scanning) { |
527 | efivar_entry_iter_end(); | |
528 | efivar_unregister(entry); | |
529 | } else | |
530 | efivar_entry_iter_end(); | |
a9499fa7 TG |
531 | |
532 | /* It's dead Jim.... */ | |
533 | return count; | |
534 | } | |
535 | ||
536 | /** | |
537 | * efivar_create_sysfs_entry - create a new entry in sysfs | |
538 | * @new_var: efivar entry to create | |
539 | * | |
f7ef7e3e | 540 | * Returns 0 on success, negative error code on failure |
a9499fa7 TG |
541 | */ |
542 | static int | |
543 | efivar_create_sysfs_entry(struct efivar_entry *new_var) | |
544 | { | |
e0d64e6a | 545 | int short_name_size; |
a9499fa7 | 546 | char *short_name; |
e0d64e6a PJ |
547 | unsigned long utf8_name_size; |
548 | efi_char16_t *variable_name = new_var->var.VariableName; | |
f7ef7e3e | 549 | int ret; |
a9499fa7 | 550 | |
a9499fa7 | 551 | /* |
e0d64e6a | 552 | * Length of the variable bytes in UTF8, plus the '-' separator, |
a9499fa7 TG |
553 | * plus the GUID, plus trailing NUL |
554 | */ | |
e0d64e6a PJ |
555 | utf8_name_size = ucs2_utf8size(variable_name); |
556 | short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1; | |
a9499fa7 | 557 | |
e0d64e6a | 558 | short_name = kmalloc(short_name_size, GFP_KERNEL); |
7b2dd6d2 | 559 | if (!short_name) |
f7ef7e3e | 560 | return -ENOMEM; |
a9499fa7 | 561 | |
e0d64e6a PJ |
562 | ucs2_as_utf8(short_name, variable_name, short_name_size); |
563 | ||
a9499fa7 TG |
564 | /* This is ugly, but necessary to separate one vendor's |
565 | private variables from another's. */ | |
e0d64e6a | 566 | short_name[utf8_name_size] = '-'; |
26e02272 | 567 | efi_guid_to_str(&new_var->var.VendorGuid, |
e0d64e6a | 568 | short_name + utf8_name_size + 1); |
a9499fa7 TG |
569 | |
570 | new_var->kobj.kset = efivars_kset; | |
571 | ||
f7ef7e3e | 572 | ret = kobject_init_and_add(&new_var->kobj, &efivar_ktype, |
a9499fa7 TG |
573 | NULL, "%s", short_name); |
574 | kfree(short_name); | |
f7ef7e3e DC |
575 | if (ret) |
576 | return ret; | |
a9499fa7 TG |
577 | |
578 | kobject_uevent(&new_var->kobj, KOBJ_ADD); | |
21b3ddd3 SC |
579 | if (efivar_entry_add(new_var, &efivar_sysfs_list)) { |
580 | efivar_unregister(new_var); | |
581 | return -EINTR; | |
582 | } | |
a9499fa7 TG |
583 | |
584 | return 0; | |
585 | } | |
586 | ||
587 | static int | |
588 | create_efivars_bin_attributes(void) | |
589 | { | |
590 | struct bin_attribute *attr; | |
591 | int error; | |
592 | ||
593 | /* new_var */ | |
594 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
595 | if (!attr) | |
596 | return -ENOMEM; | |
597 | ||
598 | attr->attr.name = "new_var"; | |
599 | attr->attr.mode = 0200; | |
600 | attr->write = efivar_create; | |
601 | efivars_new_var = attr; | |
602 | ||
603 | /* del_var */ | |
604 | attr = kzalloc(sizeof(*attr), GFP_KERNEL); | |
605 | if (!attr) { | |
606 | error = -ENOMEM; | |
607 | goto out_free; | |
608 | } | |
609 | attr->attr.name = "del_var"; | |
610 | attr->attr.mode = 0200; | |
611 | attr->write = efivar_delete; | |
612 | efivars_del_var = attr; | |
613 | ||
614 | sysfs_bin_attr_init(efivars_new_var); | |
615 | sysfs_bin_attr_init(efivars_del_var); | |
616 | ||
617 | /* Register */ | |
618 | error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var); | |
619 | if (error) { | |
620 | printk(KERN_ERR "efivars: unable to create new_var sysfs file" | |
621 | " due to error %d\n", error); | |
622 | goto out_free; | |
623 | } | |
624 | ||
625 | error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var); | |
626 | if (error) { | |
627 | printk(KERN_ERR "efivars: unable to create del_var sysfs file" | |
628 | " due to error %d\n", error); | |
629 | sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); | |
630 | goto out_free; | |
631 | } | |
632 | ||
633 | return 0; | |
634 | out_free: | |
635 | kfree(efivars_del_var); | |
636 | efivars_del_var = NULL; | |
637 | kfree(efivars_new_var); | |
638 | efivars_new_var = NULL; | |
639 | return error; | |
640 | } | |
641 | ||
642 | static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor, | |
643 | unsigned long name_size, void *data) | |
644 | { | |
645 | struct efivar_entry *entry = data; | |
646 | ||
647 | if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false)) | |
648 | return 0; | |
649 | ||
650 | memcpy(entry->var.VariableName, name, name_size); | |
651 | memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); | |
652 | ||
653 | return 1; | |
654 | } | |
655 | ||
656 | static void efivar_update_sysfs_entries(struct work_struct *work) | |
657 | { | |
658 | struct efivar_entry *entry; | |
659 | int err; | |
660 | ||
a9499fa7 TG |
661 | /* Add new sysfs entries */ |
662 | while (1) { | |
d51df2c5 SA |
663 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
664 | if (!entry) | |
665 | return; | |
a9499fa7 TG |
666 | |
667 | err = efivar_init(efivar_update_sysfs_entry, entry, | |
1cfd6316 | 668 | false, &efivar_sysfs_list); |
a9499fa7 TG |
669 | if (!err) |
670 | break; | |
671 | ||
672 | efivar_create_sysfs_entry(entry); | |
673 | } | |
674 | ||
675 | kfree(entry); | |
676 | } | |
677 | ||
678 | static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor, | |
679 | unsigned long name_size, void *data) | |
680 | { | |
681 | struct efivar_entry *entry; | |
682 | ||
683 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); | |
684 | if (!entry) | |
685 | return -ENOMEM; | |
686 | ||
687 | memcpy(entry->var.VariableName, name, name_size); | |
688 | memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); | |
689 | ||
690 | efivar_create_sysfs_entry(entry); | |
691 | ||
692 | return 0; | |
693 | } | |
694 | ||
695 | static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data) | |
696 | { | |
21b3ddd3 SC |
697 | int err = efivar_entry_remove(entry); |
698 | ||
699 | if (err) | |
700 | return err; | |
a9499fa7 TG |
701 | efivar_unregister(entry); |
702 | return 0; | |
703 | } | |
704 | ||
6f9dd30c | 705 | static void efivars_sysfs_exit(void) |
a9499fa7 TG |
706 | { |
707 | /* Remove all entries and destroy */ | |
21b3ddd3 SC |
708 | int err; |
709 | ||
710 | err = __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, | |
711 | NULL, NULL); | |
712 | if (err) { | |
713 | pr_err("efivars: Failed to destroy sysfs entries\n"); | |
714 | return; | |
715 | } | |
a9499fa7 TG |
716 | |
717 | if (efivars_new_var) | |
718 | sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); | |
719 | if (efivars_del_var) | |
720 | sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var); | |
721 | kfree(efivars_new_var); | |
722 | kfree(efivars_del_var); | |
723 | kset_unregister(efivars_kset); | |
724 | } | |
725 | ||
726 | int efivars_sysfs_init(void) | |
727 | { | |
728 | struct kobject *parent_kobj = efivars_kobject(); | |
729 | int error = 0; | |
730 | ||
d320c079 MF |
731 | if (!efi_enabled(EFI_RUNTIME_SERVICES)) |
732 | return -ENODEV; | |
733 | ||
a9499fa7 TG |
734 | /* No efivars has been registered yet */ |
735 | if (!parent_kobj) | |
736 | return 0; | |
737 | ||
738 | printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, | |
739 | EFIVARS_DATE); | |
740 | ||
741 | efivars_kset = kset_create_and_add("vars", NULL, parent_kobj); | |
742 | if (!efivars_kset) { | |
743 | printk(KERN_ERR "efivars: Subsystem registration failed.\n"); | |
744 | return -ENOMEM; | |
745 | } | |
746 | ||
1cfd6316 | 747 | efivar_init(efivars_sysfs_callback, NULL, true, &efivar_sysfs_list); |
a9499fa7 TG |
748 | |
749 | error = create_efivars_bin_attributes(); | |
750 | if (error) { | |
751 | efivars_sysfs_exit(); | |
752 | return error; | |
753 | } | |
754 | ||
755 | INIT_WORK(&efivar_work, efivar_update_sysfs_entries); | |
756 | ||
757 | return 0; | |
758 | } | |
759 | EXPORT_SYMBOL_GPL(efivars_sysfs_init); | |
760 | ||
761 | module_init(efivars_sysfs_init); | |
762 | module_exit(efivars_sysfs_exit); |