1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #define pr_fmt(fmt) "efi: " fmt |
3 | |
4 | #include <linux/init.h> |
5 | #include <linux/kernel.h> |
6 | #include <linux/string.h> |
7 | #include <linux/time.h> |
8 | #include <linux/types.h> |
9 | #include <linux/efi.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/memblock.h> |
12 | #include <linux/acpi.h> |
13 | #include <linux/dmi.h> |
14 | |
15 | #include <asm/e820/api.h> |
16 | #include <asm/efi.h> |
17 | #include <asm/uv/uv.h> |
18 | #include <asm/cpu_device_id.h> |
19 | #include <asm/realmode.h> |
20 | #include <asm/reboot.h> |
21 | |
22 | #define EFI_MIN_RESERVE 5120 |
23 | |
24 | #define EFI_DUMMY_GUID \ |
25 | EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9) |
26 | |
27 | #define QUARK_CSH_SIGNATURE 0x5f435348 /* _CSH */ |
28 | #define 0x400 |
29 | |
30 | /* |
31 | * Header prepended to the standard EFI capsule on Quark systems the are based |
32 | * on Intel firmware BSP. |
33 | * @csh_signature: Unique identifier to sanity check signed module |
34 | * presence ("_CSH"). |
35 | * @version: Current version of CSH used. Should be one for Quark A0. |
36 | * @modulesize: Size of the entire module including the module header |
37 | * and payload. |
38 | * @security_version_number_index: Index of SVN to use for validation of signed |
39 | * module. |
40 | * @security_version_number: Used to prevent against roll back of modules. |
41 | * @rsvd_module_id: Currently unused for Clanton (Quark). |
42 | * @rsvd_module_vendor: Vendor Identifier. For Intel products value is |
43 | * 0x00008086. |
44 | * @rsvd_date: BCD representation of build date as yyyymmdd, where |
45 | * yyyy=4 digit year, mm=1-12, dd=1-31. |
46 | * @headersize: Total length of the header including including any |
47 | * padding optionally added by the signing tool. |
48 | * @hash_algo: What Hash is used in the module signing. |
49 | * @cryp_algo: What Crypto is used in the module signing. |
50 | * @keysize: Total length of the key data including including any |
51 | * padding optionally added by the signing tool. |
52 | * @signaturesize: Total length of the signature including including any |
53 | * padding optionally added by the signing tool. |
54 | * @rsvd_next_header: 32-bit pointer to the next Secure Boot Module in the |
55 | * chain, if there is a next header. |
56 | * @rsvd: Reserved, padding structure to required size. |
57 | * |
58 | * See also QuartSecurityHeader_t in |
59 | * Quark_EDKII_v1.2.1.1/QuarkPlatformPkg/Include/QuarkBootRom.h |
60 | * from https://downloadcenter.intel.com/download/23197/Intel-Quark-SoC-X1000-Board-Support-Package-BSP |
61 | */ |
62 | struct { |
63 | u32 ; |
64 | u32 ; |
65 | u32 ; |
66 | u32 ; |
67 | u32 ; |
68 | u32 ; |
69 | u32 ; |
70 | u32 ; |
71 | u32 ; |
72 | u32 ; |
73 | u32 ; |
74 | u32 ; |
75 | u32 ; |
76 | u32 ; |
77 | u32 [2]; |
78 | }; |
79 | |
80 | static const efi_char16_t efi_dummy_name[] = L"DUMMY" ; |
81 | |
82 | static bool efi_no_storage_paranoia; |
83 | |
84 | /* |
85 | * Some firmware implementations refuse to boot if there's insufficient |
86 | * space in the variable store. The implementation of garbage collection |
87 | * in some FW versions causes stale (deleted) variables to take up space |
88 | * longer than intended and space is only freed once the store becomes |
89 | * almost completely full. |
90 | * |
91 | * Enabling this option disables the space checks in |
92 | * efi_query_variable_store() and forces garbage collection. |
93 | * |
94 | * Only enable this option if deleting EFI variables does not free up |
95 | * space in your variable store, e.g. if despite deleting variables |
96 | * you're unable to create new ones. |
97 | */ |
98 | static int __init setup_storage_paranoia(char *arg) |
99 | { |
100 | efi_no_storage_paranoia = true; |
101 | return 0; |
102 | } |
103 | early_param("efi_no_storage_paranoia" , setup_storage_paranoia); |
104 | |
105 | /* |
106 | * Deleting the dummy variable which kicks off garbage collection |
107 | */ |
108 | void efi_delete_dummy_variable(void) |
109 | { |
110 | efi.set_variable_nonblocking((efi_char16_t *)efi_dummy_name, |
111 | &EFI_DUMMY_GUID, |
112 | EFI_VARIABLE_NON_VOLATILE | |
113 | EFI_VARIABLE_BOOTSERVICE_ACCESS | |
114 | EFI_VARIABLE_RUNTIME_ACCESS, 0, NULL); |
115 | } |
116 | |
117 | u64 efivar_reserved_space(void) |
118 | { |
119 | if (efi_no_storage_paranoia) |
120 | return 0; |
121 | return EFI_MIN_RESERVE; |
122 | } |
123 | EXPORT_SYMBOL_GPL(efivar_reserved_space); |
124 | |
125 | /* |
126 | * In the nonblocking case we do not attempt to perform garbage |
127 | * collection if we do not have enough free space. Rather, we do the |
128 | * bare minimum check and give up immediately if the available space |
129 | * is below EFI_MIN_RESERVE. |
130 | * |
131 | * This function is intended to be small and simple because it is |
132 | * invoked from crash handler paths. |
133 | */ |
134 | static efi_status_t |
135 | query_variable_store_nonblocking(u32 attributes, unsigned long size) |
136 | { |
137 | efi_status_t status; |
138 | u64 storage_size, remaining_size, max_size; |
139 | |
140 | status = efi.query_variable_info_nonblocking(attributes, &storage_size, |
141 | &remaining_size, |
142 | &max_size); |
143 | if (status != EFI_SUCCESS) |
144 | return status; |
145 | |
146 | if (remaining_size - size < EFI_MIN_RESERVE) |
147 | return EFI_OUT_OF_RESOURCES; |
148 | |
149 | return EFI_SUCCESS; |
150 | } |
151 | |
152 | /* |
153 | * Some firmware implementations refuse to boot if there's insufficient space |
154 | * in the variable store. Ensure that we never use more than a safe limit. |
155 | * |
156 | * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable |
157 | * store. |
158 | */ |
159 | efi_status_t efi_query_variable_store(u32 attributes, unsigned long size, |
160 | bool nonblocking) |
161 | { |
162 | efi_status_t status; |
163 | u64 storage_size, remaining_size, max_size; |
164 | |
165 | if (!(attributes & EFI_VARIABLE_NON_VOLATILE)) |
166 | return 0; |
167 | |
168 | if (nonblocking) |
169 | return query_variable_store_nonblocking(attributes, size); |
170 | |
171 | status = efi.query_variable_info(attributes, &storage_size, |
172 | &remaining_size, &max_size); |
173 | if (status != EFI_SUCCESS) |
174 | return status; |
175 | |
176 | /* |
177 | * We account for that by refusing the write if permitting it would |
178 | * reduce the available space to under 5KB. This figure was provided by |
179 | * Samsung, so should be safe. |
180 | */ |
181 | if ((remaining_size - size < EFI_MIN_RESERVE) && |
182 | !efi_no_storage_paranoia) { |
183 | |
184 | /* |
185 | * Triggering garbage collection may require that the firmware |
186 | * generate a real EFI_OUT_OF_RESOURCES error. We can force |
187 | * that by attempting to use more space than is available. |
188 | */ |
189 | unsigned long dummy_size = remaining_size + 1024; |
190 | void *dummy = kzalloc(size: dummy_size, GFP_KERNEL); |
191 | |
192 | if (!dummy) |
193 | return EFI_OUT_OF_RESOURCES; |
194 | |
195 | status = efi.set_variable((efi_char16_t *)efi_dummy_name, |
196 | &EFI_DUMMY_GUID, |
197 | EFI_VARIABLE_NON_VOLATILE | |
198 | EFI_VARIABLE_BOOTSERVICE_ACCESS | |
199 | EFI_VARIABLE_RUNTIME_ACCESS, |
200 | dummy_size, dummy); |
201 | |
202 | if (status == EFI_SUCCESS) { |
203 | /* |
204 | * This should have failed, so if it didn't make sure |
205 | * that we delete it... |
206 | */ |
207 | efi_delete_dummy_variable(); |
208 | } |
209 | |
210 | kfree(objp: dummy); |
211 | |
212 | /* |
213 | * The runtime code may now have triggered a garbage collection |
214 | * run, so check the variable info again |
215 | */ |
216 | status = efi.query_variable_info(attributes, &storage_size, |
217 | &remaining_size, &max_size); |
218 | |
219 | if (status != EFI_SUCCESS) |
220 | return status; |
221 | |
222 | /* |
223 | * There still isn't enough room, so return an error |
224 | */ |
225 | if (remaining_size - size < EFI_MIN_RESERVE) |
226 | return EFI_OUT_OF_RESOURCES; |
227 | } |
228 | |
229 | return EFI_SUCCESS; |
230 | } |
231 | EXPORT_SYMBOL_GPL(efi_query_variable_store); |
232 | |
233 | /* |
234 | * The UEFI specification makes it clear that the operating system is |
235 | * free to do whatever it wants with boot services code after |
236 | * ExitBootServices() has been called. Ignoring this recommendation a |
237 | * significant bunch of EFI implementations continue calling into boot |
238 | * services code (SetVirtualAddressMap). In order to work around such |
239 | * buggy implementations we reserve boot services region during EFI |
240 | * init and make sure it stays executable. Then, after |
241 | * SetVirtualAddressMap(), it is discarded. |
242 | * |
243 | * However, some boot services regions contain data that is required |
244 | * by drivers, so we need to track which memory ranges can never be |
245 | * freed. This is done by tagging those regions with the |
246 | * EFI_MEMORY_RUNTIME attribute. |
247 | * |
248 | * Any driver that wants to mark a region as reserved must use |
249 | * efi_mem_reserve() which will insert a new EFI memory descriptor |
250 | * into efi.memmap (splitting existing regions if necessary) and tag |
251 | * it with EFI_MEMORY_RUNTIME. |
252 | */ |
253 | void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size) |
254 | { |
255 | struct efi_memory_map_data data = { 0 }; |
256 | struct efi_mem_range mr; |
257 | efi_memory_desc_t md; |
258 | int num_entries; |
259 | void *new; |
260 | |
261 | if (efi_mem_desc_lookup(phys_addr: addr, out_md: &md) || |
262 | md.type != EFI_BOOT_SERVICES_DATA) { |
263 | pr_err("Failed to lookup EFI memory descriptor for %pa\n" , &addr); |
264 | return; |
265 | } |
266 | |
267 | if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) { |
268 | pr_err("Region spans EFI memory descriptors, %pa\n" , &addr); |
269 | return; |
270 | } |
271 | |
272 | size += addr % EFI_PAGE_SIZE; |
273 | size = round_up(size, EFI_PAGE_SIZE); |
274 | addr = round_down(addr, EFI_PAGE_SIZE); |
275 | |
276 | mr.range.start = addr; |
277 | mr.range.end = addr + size - 1; |
278 | mr.attribute = md.attribute | EFI_MEMORY_RUNTIME; |
279 | |
280 | num_entries = efi_memmap_split_count(md: &md, range: &mr.range); |
281 | num_entries += efi.memmap.nr_map; |
282 | |
283 | if (efi_memmap_alloc(num_entries, data: &data) != 0) { |
284 | pr_err("Could not allocate boot services memmap\n" ); |
285 | return; |
286 | } |
287 | |
288 | new = early_memremap_prot(phys_addr: data.phys_map, size: data.size, |
289 | pgprot_val(pgprot_encrypted(FIXMAP_PAGE_NORMAL))); |
290 | if (!new) { |
291 | pr_err("Failed to map new boot services memmap\n" ); |
292 | return; |
293 | } |
294 | |
295 | efi_memmap_insert(old_memmap: &efi.memmap, buf: new, mem: &mr); |
296 | early_memunmap(addr: new, size: data.size); |
297 | |
298 | efi_memmap_install(data: &data); |
299 | e820__range_update(start: addr, size, old_type: E820_TYPE_RAM, new_type: E820_TYPE_RESERVED); |
300 | e820__update_table(table: e820_table); |
301 | } |
302 | |
303 | /* |
304 | * Helper function for efi_reserve_boot_services() to figure out if we |
305 | * can free regions in efi_free_boot_services(). |
306 | * |
307 | * Use this function to ensure we do not free regions owned by somebody |
308 | * else. We must only reserve (and then free) regions: |
309 | * |
310 | * - Not within any part of the kernel |
311 | * - Not the BIOS reserved area (E820_TYPE_RESERVED, E820_TYPE_NVS, etc) |
312 | */ |
313 | static __init bool can_free_region(u64 start, u64 size) |
314 | { |
315 | if (start + size > __pa_symbol(_text) && start <= __pa_symbol(_end)) |
316 | return false; |
317 | |
318 | if (!e820__mapped_all(start, end: start+size, type: E820_TYPE_RAM)) |
319 | return false; |
320 | |
321 | return true; |
322 | } |
323 | |
324 | void __init efi_reserve_boot_services(void) |
325 | { |
326 | efi_memory_desc_t *md; |
327 | |
328 | if (!efi_enabled(EFI_MEMMAP)) |
329 | return; |
330 | |
331 | for_each_efi_memory_desc(md) { |
332 | u64 start = md->phys_addr; |
333 | u64 size = md->num_pages << EFI_PAGE_SHIFT; |
334 | bool already_reserved; |
335 | |
336 | if (md->type != EFI_BOOT_SERVICES_CODE && |
337 | md->type != EFI_BOOT_SERVICES_DATA) |
338 | continue; |
339 | |
340 | already_reserved = memblock_is_region_reserved(base: start, size); |
341 | |
342 | /* |
343 | * Because the following memblock_reserve() is paired |
344 | * with memblock_free_late() for this region in |
345 | * efi_free_boot_services(), we must be extremely |
346 | * careful not to reserve, and subsequently free, |
347 | * critical regions of memory (like the kernel image) or |
348 | * those regions that somebody else has already |
349 | * reserved. |
350 | * |
351 | * A good example of a critical region that must not be |
352 | * freed is page zero (first 4Kb of memory), which may |
353 | * contain boot services code/data but is marked |
354 | * E820_TYPE_RESERVED by trim_bios_range(). |
355 | */ |
356 | if (!already_reserved) { |
357 | memblock_reserve(base: start, size); |
358 | |
359 | /* |
360 | * If we are the first to reserve the region, no |
361 | * one else cares about it. We own it and can |
362 | * free it later. |
363 | */ |
364 | if (can_free_region(start, size)) |
365 | continue; |
366 | } |
367 | |
368 | /* |
369 | * We don't own the region. We must not free it. |
370 | * |
371 | * Setting this bit for a boot services region really |
372 | * doesn't make sense as far as the firmware is |
373 | * concerned, but it does provide us with a way to tag |
374 | * those regions that must not be paired with |
375 | * memblock_free_late(). |
376 | */ |
377 | md->attribute |= EFI_MEMORY_RUNTIME; |
378 | } |
379 | } |
380 | |
381 | /* |
382 | * Apart from having VA mappings for EFI boot services code/data regions, |
383 | * (duplicate) 1:1 mappings were also created as a quirk for buggy firmware. So, |
384 | * unmap both 1:1 and VA mappings. |
385 | */ |
386 | static void __init efi_unmap_pages(efi_memory_desc_t *md) |
387 | { |
388 | pgd_t *pgd = efi_mm.pgd; |
389 | u64 pa = md->phys_addr; |
390 | u64 va = md->virt_addr; |
391 | |
392 | /* |
393 | * EFI mixed mode has all RAM mapped to access arguments while making |
394 | * EFI runtime calls, hence don't unmap EFI boot services code/data |
395 | * regions. |
396 | */ |
397 | if (efi_is_mixed()) |
398 | return; |
399 | |
400 | if (kernel_unmap_pages_in_pgd(pgd, address: pa, numpages: md->num_pages)) |
401 | pr_err("Failed to unmap 1:1 mapping for 0x%llx\n" , pa); |
402 | |
403 | if (kernel_unmap_pages_in_pgd(pgd, address: va, numpages: md->num_pages)) |
404 | pr_err("Failed to unmap VA mapping for 0x%llx\n" , va); |
405 | } |
406 | |
407 | void __init efi_free_boot_services(void) |
408 | { |
409 | struct efi_memory_map_data data = { 0 }; |
410 | efi_memory_desc_t *md; |
411 | int num_entries = 0; |
412 | void *new, *new_md; |
413 | |
414 | /* Keep all regions for /sys/kernel/debug/efi */ |
415 | if (efi_enabled(EFI_DBG)) |
416 | return; |
417 | |
418 | for_each_efi_memory_desc(md) { |
419 | unsigned long long start = md->phys_addr; |
420 | unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; |
421 | size_t rm_size; |
422 | |
423 | if (md->type != EFI_BOOT_SERVICES_CODE && |
424 | md->type != EFI_BOOT_SERVICES_DATA) { |
425 | num_entries++; |
426 | continue; |
427 | } |
428 | |
429 | /* Do not free, someone else owns it: */ |
430 | if (md->attribute & EFI_MEMORY_RUNTIME) { |
431 | num_entries++; |
432 | continue; |
433 | } |
434 | |
435 | /* |
436 | * Before calling set_virtual_address_map(), EFI boot services |
437 | * code/data regions were mapped as a quirk for buggy firmware. |
438 | * Unmap them from efi_pgd before freeing them up. |
439 | */ |
440 | efi_unmap_pages(md); |
441 | |
442 | /* |
443 | * Nasty quirk: if all sub-1MB memory is used for boot |
444 | * services, we can get here without having allocated the |
445 | * real mode trampoline. It's too late to hand boot services |
446 | * memory back to the memblock allocator, so instead |
447 | * try to manually allocate the trampoline if needed. |
448 | * |
449 | * I've seen this on a Dell XPS 13 9350 with firmware |
450 | * 1.4.4 with SGX enabled booting Linux via Fedora 24's |
451 | * grub2-efi on a hard disk. (And no, I don't know why |
452 | * this happened, but Linux should still try to boot rather |
453 | * panicking early.) |
454 | */ |
455 | rm_size = real_mode_size_needed(); |
456 | if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) { |
457 | set_real_mode_mem(start); |
458 | start += rm_size; |
459 | size -= rm_size; |
460 | } |
461 | |
462 | /* |
463 | * Don't free memory under 1M for two reasons: |
464 | * - BIOS might clobber it |
465 | * - Crash kernel needs it to be reserved |
466 | */ |
467 | if (start + size < SZ_1M) |
468 | continue; |
469 | if (start < SZ_1M) { |
470 | size -= (SZ_1M - start); |
471 | start = SZ_1M; |
472 | } |
473 | |
474 | memblock_free_late(base: start, size); |
475 | } |
476 | |
477 | if (!num_entries) |
478 | return; |
479 | |
480 | if (efi_memmap_alloc(num_entries, data: &data) != 0) { |
481 | pr_err("Failed to allocate new EFI memmap\n" ); |
482 | return; |
483 | } |
484 | |
485 | new = memremap(offset: data.phys_map, size: data.size, flags: MEMREMAP_WB); |
486 | if (!new) { |
487 | pr_err("Failed to map new EFI memmap\n" ); |
488 | return; |
489 | } |
490 | |
491 | /* |
492 | * Build a new EFI memmap that excludes any boot services |
493 | * regions that are not tagged EFI_MEMORY_RUNTIME, since those |
494 | * regions have now been freed. |
495 | */ |
496 | new_md = new; |
497 | for_each_efi_memory_desc(md) { |
498 | if (!(md->attribute & EFI_MEMORY_RUNTIME) && |
499 | (md->type == EFI_BOOT_SERVICES_CODE || |
500 | md->type == EFI_BOOT_SERVICES_DATA)) |
501 | continue; |
502 | |
503 | memcpy(new_md, md, efi.memmap.desc_size); |
504 | new_md += efi.memmap.desc_size; |
505 | } |
506 | |
507 | memunmap(addr: new); |
508 | |
509 | if (efi_memmap_install(data: &data) != 0) { |
510 | pr_err("Could not install new EFI memmap\n" ); |
511 | return; |
512 | } |
513 | } |
514 | |
515 | /* |
516 | * A number of config table entries get remapped to virtual addresses |
517 | * after entering EFI virtual mode. However, the kexec kernel requires |
518 | * their physical addresses therefore we pass them via setup_data and |
519 | * correct those entries to their respective physical addresses here. |
520 | * |
521 | * Currently only handles smbios which is necessary for some firmware |
522 | * implementation. |
523 | */ |
524 | int __init efi_reuse_config(u64 tables, int nr_tables) |
525 | { |
526 | int i, sz, ret = 0; |
527 | void *p, *tablep; |
528 | struct efi_setup_data *data; |
529 | |
530 | if (nr_tables == 0) |
531 | return 0; |
532 | |
533 | if (!efi_setup) |
534 | return 0; |
535 | |
536 | if (!efi_enabled(EFI_64BIT)) |
537 | return 0; |
538 | |
539 | data = early_memremap(phys_addr: efi_setup, size: sizeof(*data)); |
540 | if (!data) { |
541 | ret = -ENOMEM; |
542 | goto out; |
543 | } |
544 | |
545 | if (!data->smbios) |
546 | goto out_memremap; |
547 | |
548 | sz = sizeof(efi_config_table_64_t); |
549 | |
550 | p = tablep = early_memremap(phys_addr: tables, size: nr_tables * sz); |
551 | if (!p) { |
552 | pr_err("Could not map Configuration table!\n" ); |
553 | ret = -ENOMEM; |
554 | goto out_memremap; |
555 | } |
556 | |
557 | for (i = 0; i < nr_tables; i++) { |
558 | efi_guid_t guid; |
559 | |
560 | guid = ((efi_config_table_64_t *)p)->guid; |
561 | |
562 | if (!efi_guidcmp(left: guid, SMBIOS_TABLE_GUID)) |
563 | ((efi_config_table_64_t *)p)->table = data->smbios; |
564 | p += sz; |
565 | } |
566 | early_memunmap(addr: tablep, size: nr_tables * sz); |
567 | |
568 | out_memremap: |
569 | early_memunmap(addr: data, size: sizeof(*data)); |
570 | out: |
571 | return ret; |
572 | } |
573 | |
574 | void __init efi_apply_memmap_quirks(void) |
575 | { |
576 | /* |
577 | * Once setup is done earlier, unmap the EFI memory map on mismatched |
578 | * firmware/kernel architectures since there is no support for runtime |
579 | * services. |
580 | */ |
581 | if (!efi_runtime_supported()) { |
582 | pr_info("Setup done, disabling due to 32/64-bit mismatch\n" ); |
583 | efi_memmap_unmap(); |
584 | } |
585 | } |
586 | |
587 | /* |
588 | * For most modern platforms the preferred method of powering off is via |
589 | * ACPI. However, there are some that are known to require the use of |
590 | * EFI runtime services and for which ACPI does not work at all. |
591 | * |
592 | * Using EFI is a last resort, to be used only if no other option |
593 | * exists. |
594 | */ |
595 | bool efi_reboot_required(void) |
596 | { |
597 | if (!acpi_gbl_reduced_hardware) |
598 | return false; |
599 | |
600 | efi_reboot_quirk_mode = EFI_RESET_WARM; |
601 | return true; |
602 | } |
603 | |
604 | bool efi_poweroff_required(void) |
605 | { |
606 | return acpi_gbl_reduced_hardware || acpi_no_s5; |
607 | } |
608 | |
609 | #ifdef CONFIG_EFI_CAPSULE_QUIRK_QUARK_CSH |
610 | |
611 | static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff, |
612 | size_t hdr_bytes) |
613 | { |
614 | struct quark_security_header *csh = *pkbuff; |
615 | |
616 | /* Only process data block that is larger than the security header */ |
617 | if (hdr_bytes < sizeof(struct quark_security_header)) |
618 | return 0; |
619 | |
620 | if (csh->csh_signature != QUARK_CSH_SIGNATURE || |
621 | csh->headersize != QUARK_SECURITY_HEADER_SIZE) |
622 | return 1; |
623 | |
624 | /* Only process data block if EFI header is included */ |
625 | if (hdr_bytes < QUARK_SECURITY_HEADER_SIZE + |
626 | sizeof(efi_capsule_header_t)) |
627 | return 0; |
628 | |
629 | pr_debug("Quark security header detected\n" ); |
630 | |
631 | if (csh->rsvd_next_header != 0) { |
632 | pr_err("multiple Quark security headers not supported\n" ); |
633 | return -EINVAL; |
634 | } |
635 | |
636 | *pkbuff += csh->headersize; |
637 | cap_info->total_size = csh->headersize; |
638 | |
639 | /* |
640 | * Update the first page pointer to skip over the CSH header. |
641 | */ |
642 | cap_info->phys[0] += csh->headersize; |
643 | |
644 | /* |
645 | * cap_info->capsule should point at a virtual mapping of the entire |
646 | * capsule, starting at the capsule header. Our image has the Quark |
647 | * security header prepended, so we cannot rely on the default vmap() |
648 | * mapping created by the generic capsule code. |
649 | * Given that the Quark firmware does not appear to care about the |
650 | * virtual mapping, let's just point cap_info->capsule at our copy |
651 | * of the capsule header. |
652 | */ |
653 | cap_info->capsule = &cap_info->header; |
654 | |
655 | return 1; |
656 | } |
657 | |
658 | static const struct x86_cpu_id efi_capsule_quirk_ids[] = { |
659 | X86_MATCH_VENDOR_FAM_MODEL(INTEL, 5, INTEL_FAM5_QUARK_X1000, |
660 | &qrk_capsule_setup_info), |
661 | { } |
662 | }; |
663 | |
664 | int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff, |
665 | size_t hdr_bytes) |
666 | { |
667 | int (*quirk_handler)(struct capsule_info *, void **, size_t); |
668 | const struct x86_cpu_id *id; |
669 | int ret; |
670 | |
671 | if (hdr_bytes < sizeof(efi_capsule_header_t)) |
672 | return 0; |
673 | |
674 | cap_info->total_size = 0; |
675 | |
676 | id = x86_match_cpu(efi_capsule_quirk_ids); |
677 | if (id) { |
678 | /* |
679 | * The quirk handler is supposed to return |
680 | * - a value > 0 if the setup should continue, after advancing |
681 | * kbuff as needed |
682 | * - 0 if not enough hdr_bytes are available yet |
683 | * - a negative error code otherwise |
684 | */ |
685 | quirk_handler = (typeof(quirk_handler))id->driver_data; |
686 | ret = quirk_handler(cap_info, &kbuff, hdr_bytes); |
687 | if (ret <= 0) |
688 | return ret; |
689 | } |
690 | |
691 | memcpy(&cap_info->header, kbuff, sizeof(cap_info->header)); |
692 | |
693 | cap_info->total_size += cap_info->header.imagesize; |
694 | |
695 | return __efi_capsule_setup_info(cap_info); |
696 | } |
697 | |
698 | #endif |
699 | |
700 | /* |
701 | * If any access by any efi runtime service causes a page fault, then, |
702 | * 1. If it's efi_reset_system(), reboot through BIOS. |
703 | * 2. If any other efi runtime service, then |
704 | * a. Return error status to the efi caller process. |
705 | * b. Disable EFI Runtime Services forever and |
706 | * c. Freeze efi_rts_wq and schedule new process. |
707 | * |
708 | * @return: Returns, if the page fault is not handled. This function |
709 | * will never return if the page fault is handled successfully. |
710 | */ |
711 | void efi_crash_gracefully_on_page_fault(unsigned long phys_addr) |
712 | { |
713 | if (!IS_ENABLED(CONFIG_X86_64)) |
714 | return; |
715 | |
716 | /* |
717 | * If we get an interrupt/NMI while processing an EFI runtime service |
718 | * then this is a regular OOPS, not an EFI failure. |
719 | */ |
720 | if (in_interrupt()) |
721 | return; |
722 | |
723 | /* |
724 | * Make sure that an efi runtime service caused the page fault. |
725 | * READ_ONCE() because we might be OOPSing in a different thread, |
726 | * and we don't want to trip KTSAN while trying to OOPS. |
727 | */ |
728 | if (READ_ONCE(efi_rts_work.efi_rts_id) == EFI_NONE || |
729 | current_work() != &efi_rts_work.work) |
730 | return; |
731 | |
732 | /* |
733 | * Address range 0x0000 - 0x0fff is always mapped in the efi_pgd, so |
734 | * page faulting on these addresses isn't expected. |
735 | */ |
736 | if (phys_addr <= 0x0fff) |
737 | return; |
738 | |
739 | /* |
740 | * Print stack trace as it might be useful to know which EFI Runtime |
741 | * Service is buggy. |
742 | */ |
743 | WARN(1, FW_BUG "Page fault caused by firmware at PA: 0x%lx\n" , |
744 | phys_addr); |
745 | |
746 | /* |
747 | * Buggy efi_reset_system() is handled differently from other EFI |
748 | * Runtime Services as it doesn't use efi_rts_wq. Although, |
749 | * native_machine_emergency_restart() says that machine_real_restart() |
750 | * could fail, it's better not to complicate this fault handler |
751 | * because this case occurs *very* rarely and hence could be improved |
752 | * on a need by basis. |
753 | */ |
754 | if (efi_rts_work.efi_rts_id == EFI_RESET_SYSTEM) { |
755 | pr_info("efi_reset_system() buggy! Reboot through BIOS\n" ); |
756 | machine_real_restart(MRR_BIOS); |
757 | return; |
758 | } |
759 | |
760 | /* |
761 | * Before calling EFI Runtime Service, the kernel has switched the |
762 | * calling process to efi_mm. Hence, switch back to task_mm. |
763 | */ |
764 | arch_efi_call_virt_teardown(); |
765 | |
766 | /* Signal error status to the efi caller process */ |
767 | efi_rts_work.status = EFI_ABORTED; |
768 | complete(&efi_rts_work.efi_rts_comp); |
769 | |
770 | clear_bit(EFI_RUNTIME_SERVICES, addr: &efi.flags); |
771 | pr_info("Froze efi_rts_wq and disabled EFI Runtime Services\n" ); |
772 | |
773 | /* |
774 | * Call schedule() in an infinite loop, so that any spurious wake ups |
775 | * will never run efi_rts_wq again. |
776 | */ |
777 | for (;;) { |
778 | set_current_state(TASK_IDLE); |
779 | schedule(); |
780 | } |
781 | } |
782 | |