1 // SPDX-License-Identifier: GPL-2.0-only
2
3 /* -----------------------------------------------------------------------
4 *
5 * Copyright 2011 Intel Corporation; author Matt Fleming
6 *
7 * ----------------------------------------------------------------------- */
8
9 #include <linux/efi.h>
10 #include <linux/pci.h>
11 #include <linux/stddef.h>
12
13 #include <asm/efi.h>
14 #include <asm/e820/types.h>
15 #include <asm/setup.h>
16 #include <asm/desc.h>
17 #include <asm/boot.h>
18 #include <asm/kaslr.h>
19 #include <asm/sev.h>
20
21 #include "efistub.h"
22 #include "x86-stub.h"
23
24 extern char _bss[], _ebss[];
25
26 const efi_system_table_t *efi_system_table;
27 const efi_dxe_services_table_t *efi_dxe_table;
28 static efi_loaded_image_t *image = NULL;
29 static efi_memory_attribute_protocol_t *memattr;
30
31 typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t;
32 union sev_memory_acceptance_protocol {
33 struct {
34 efi_status_t (__efiapi * allow_unaccepted_memory)(
35 sev_memory_acceptance_protocol_t *);
36 };
37 struct {
38 u32 allow_unaccepted_memory;
39 } mixed_mode;
40 };
41
42 static efi_status_t
preserve_pci_rom_image(efi_pci_io_protocol_t * pci,struct pci_setup_rom ** __rom)43 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
44 {
45 struct pci_setup_rom *rom = NULL;
46 efi_status_t status;
47 unsigned long size;
48 uint64_t romsize;
49 void *romimage;
50
51 /*
52 * Some firmware images contain EFI function pointers at the place where
53 * the romimage and romsize fields are supposed to be. Typically the EFI
54 * code is mapped at high addresses, translating to an unrealistically
55 * large romsize. The UEFI spec limits the size of option ROMs to 16
56 * MiB so we reject any ROMs over 16 MiB in size to catch this.
57 */
58 romimage = efi_table_attr(pci, romimage);
59 romsize = efi_table_attr(pci, romsize);
60 if (!romimage || !romsize || romsize > SZ_16M)
61 return EFI_INVALID_PARAMETER;
62
63 size = romsize + sizeof(*rom);
64
65 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
66 (void **)&rom);
67 if (status != EFI_SUCCESS) {
68 efi_err("Failed to allocate memory for 'rom'\n");
69 return status;
70 }
71
72 memset(rom, 0, sizeof(*rom));
73
74 rom->data.type = SETUP_PCI;
75 rom->data.len = size - sizeof(struct setup_data);
76 rom->data.next = 0;
77 rom->pcilen = romsize;
78 *__rom = rom;
79
80 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
81 PCI_VENDOR_ID, 1, &rom->vendor);
82
83 if (status != EFI_SUCCESS) {
84 efi_err("Failed to read rom->vendor\n");
85 goto free_struct;
86 }
87
88 status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
89 PCI_DEVICE_ID, 1, &rom->devid);
90
91 if (status != EFI_SUCCESS) {
92 efi_err("Failed to read rom->devid\n");
93 goto free_struct;
94 }
95
96 status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
97 &rom->device, &rom->function);
98
99 if (status != EFI_SUCCESS)
100 goto free_struct;
101
102 memcpy(rom->romdata, romimage, romsize);
103 return status;
104
105 free_struct:
106 efi_bs_call(free_pool, rom);
107 return status;
108 }
109
110 /*
111 * There's no way to return an informative status from this function,
112 * because any analysis (and printing of error messages) needs to be
113 * done directly at the EFI function call-site.
114 *
115 * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
116 * just didn't find any PCI devices, but there's no way to tell outside
117 * the context of the call.
118 */
setup_efi_pci(struct boot_params * params)119 static void setup_efi_pci(struct boot_params *params)
120 {
121 efi_status_t status;
122 void **pci_handle = NULL;
123 efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
124 unsigned long size = 0;
125 struct setup_data *data;
126 efi_handle_t h;
127 int i;
128
129 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
130 &pci_proto, NULL, &size, pci_handle);
131
132 if (status == EFI_BUFFER_TOO_SMALL) {
133 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
134 (void **)&pci_handle);
135
136 if (status != EFI_SUCCESS) {
137 efi_err("Failed to allocate memory for 'pci_handle'\n");
138 return;
139 }
140
141 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
142 &pci_proto, NULL, &size, pci_handle);
143 }
144
145 if (status != EFI_SUCCESS)
146 goto free_handle;
147
148 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
149
150 while (data && data->next)
151 data = (struct setup_data *)(unsigned long)data->next;
152
153 for_each_efi_handle(h, pci_handle, size, i) {
154 efi_pci_io_protocol_t *pci = NULL;
155 struct pci_setup_rom *rom;
156
157 status = efi_bs_call(handle_protocol, h, &pci_proto,
158 (void **)&pci);
159 if (status != EFI_SUCCESS || !pci)
160 continue;
161
162 status = preserve_pci_rom_image(pci, &rom);
163 if (status != EFI_SUCCESS)
164 continue;
165
166 if (data)
167 data->next = (unsigned long)rom;
168 else
169 params->hdr.setup_data = (unsigned long)rom;
170
171 data = (struct setup_data *)rom;
172 }
173
174 free_handle:
175 efi_bs_call(free_pool, pci_handle);
176 }
177
retrieve_apple_device_properties(struct boot_params * boot_params)178 static void retrieve_apple_device_properties(struct boot_params *boot_params)
179 {
180 efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
181 struct setup_data *data, *new;
182 efi_status_t status;
183 u32 size = 0;
184 apple_properties_protocol_t *p;
185
186 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
187 if (status != EFI_SUCCESS)
188 return;
189
190 if (efi_table_attr(p, version) != 0x10000) {
191 efi_err("Unsupported properties proto version\n");
192 return;
193 }
194
195 efi_call_proto(p, get_all, NULL, &size);
196 if (!size)
197 return;
198
199 do {
200 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
201 size + sizeof(struct setup_data),
202 (void **)&new);
203 if (status != EFI_SUCCESS) {
204 efi_err("Failed to allocate memory for 'properties'\n");
205 return;
206 }
207
208 status = efi_call_proto(p, get_all, new->data, &size);
209
210 if (status == EFI_BUFFER_TOO_SMALL)
211 efi_bs_call(free_pool, new);
212 } while (status == EFI_BUFFER_TOO_SMALL);
213
214 new->type = SETUP_APPLE_PROPERTIES;
215 new->len = size;
216 new->next = 0;
217
218 data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
219 if (!data) {
220 boot_params->hdr.setup_data = (unsigned long)new;
221 } else {
222 while (data->next)
223 data = (struct setup_data *)(unsigned long)data->next;
224 data->next = (unsigned long)new;
225 }
226 }
227
apple_match_product_name(void)228 static bool apple_match_product_name(void)
229 {
230 static const char type1_product_matches[][15] = {
231 "MacBookPro11,3",
232 "MacBookPro11,5",
233 "MacBookPro13,3",
234 "MacBookPro14,3",
235 "MacBookPro15,1",
236 "MacBookPro15,3",
237 "MacBookPro16,1",
238 "MacBookPro16,4",
239 };
240 const struct efi_smbios_type1_record *record;
241 const u8 *product;
242
243 record = (struct efi_smbios_type1_record *)efi_get_smbios_record(1);
244 if (!record)
245 return false;
246
247 product = efi_get_smbios_string(record, product_name);
248 if (!product)
249 return false;
250
251 for (int i = 0; i < ARRAY_SIZE(type1_product_matches); i++) {
252 if (!strcmp(product, type1_product_matches[i]))
253 return true;
254 }
255
256 return false;
257 }
258
apple_set_os(void)259 static void apple_set_os(void)
260 {
261 struct {
262 unsigned long version;
263 efi_status_t (__efiapi *set_os_version)(const char *);
264 efi_status_t (__efiapi *set_os_vendor)(const char *);
265 } *set_os;
266 efi_status_t status;
267
268 if (!efi_is_64bit() || !apple_match_product_name())
269 return;
270
271 status = efi_bs_call(locate_protocol, &APPLE_SET_OS_PROTOCOL_GUID, NULL,
272 (void **)&set_os);
273 if (status != EFI_SUCCESS)
274 return;
275
276 if (set_os->version >= 2) {
277 status = set_os->set_os_vendor("Apple Inc.");
278 if (status != EFI_SUCCESS)
279 efi_err("Failed to set OS vendor via apple_set_os\n");
280 }
281
282 if (set_os->version > 0) {
283 /* The version being set doesn't seem to matter */
284 status = set_os->set_os_version("Mac OS X 10.9");
285 if (status != EFI_SUCCESS)
286 efi_err("Failed to set OS version via apple_set_os\n");
287 }
288 }
289
efi_adjust_memory_range_protection(unsigned long start,unsigned long size)290 efi_status_t efi_adjust_memory_range_protection(unsigned long start,
291 unsigned long size)
292 {
293 efi_status_t status;
294 efi_gcd_memory_space_desc_t desc;
295 unsigned long end, next;
296 unsigned long rounded_start, rounded_end;
297 unsigned long unprotect_start, unprotect_size;
298
299 rounded_start = rounddown(start, EFI_PAGE_SIZE);
300 rounded_end = roundup(start + size, EFI_PAGE_SIZE);
301
302 if (memattr != NULL) {
303 status = efi_call_proto(memattr, set_memory_attributes,
304 rounded_start,
305 rounded_end - rounded_start,
306 EFI_MEMORY_RO);
307 if (status != EFI_SUCCESS) {
308 efi_warn("Failed to set EFI_MEMORY_RO attribute\n");
309 return status;
310 }
311
312 status = efi_call_proto(memattr, clear_memory_attributes,
313 rounded_start,
314 rounded_end - rounded_start,
315 EFI_MEMORY_XP);
316 if (status != EFI_SUCCESS)
317 efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
318 return status;
319 }
320
321 if (efi_dxe_table == NULL)
322 return EFI_SUCCESS;
323
324 /*
325 * Don't modify memory region attributes, they are
326 * already suitable, to lower the possibility to
327 * encounter firmware bugs.
328 */
329
330 for (end = start + size; start < end; start = next) {
331
332 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
333
334 if (status != EFI_SUCCESS)
335 break;
336
337 next = desc.base_address + desc.length;
338
339 /*
340 * Only system memory is suitable for trampoline/kernel image placement,
341 * so only this type of memory needs its attributes to be modified.
342 */
343
344 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
345 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
346 continue;
347
348 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
349 unprotect_size = min(rounded_end, next) - unprotect_start;
350
351 status = efi_dxe_call(set_memory_space_attributes,
352 unprotect_start, unprotect_size,
353 EFI_MEMORY_WB);
354
355 if (status != EFI_SUCCESS) {
356 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
357 unprotect_start,
358 unprotect_start + unprotect_size,
359 status);
360 break;
361 }
362 }
363 return EFI_SUCCESS;
364 }
365
setup_unaccepted_memory(void)366 static void setup_unaccepted_memory(void)
367 {
368 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
369 sev_memory_acceptance_protocol_t *proto;
370 efi_status_t status;
371
372 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
373 return;
374
375 /*
376 * Enable unaccepted memory before calling exit boot services in order
377 * for the UEFI to not accept all memory on EBS.
378 */
379 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
380 (void **)&proto);
381 if (status != EFI_SUCCESS)
382 return;
383
384 status = efi_call_proto(proto, allow_unaccepted_memory);
385 if (status != EFI_SUCCESS)
386 efi_err("Memory acceptance protocol failed\n");
387 }
388
efistub_fw_vendor(void)389 static efi_char16_t *efistub_fw_vendor(void)
390 {
391 unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
392
393 return (efi_char16_t *)vendor;
394 }
395
396 static const efi_char16_t apple[] = L"Apple";
397
setup_quirks(struct boot_params * boot_params)398 static void setup_quirks(struct boot_params *boot_params)
399 {
400 if (!memcmp(efistub_fw_vendor(), apple, sizeof(apple))) {
401 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
402 retrieve_apple_device_properties(boot_params);
403
404 apple_set_os();
405 }
406 }
407
408 /*
409 * See if we have Universal Graphics Adapter (UGA) protocol
410 */
411 static efi_status_t
setup_uga(struct screen_info * si,efi_guid_t * uga_proto,unsigned long size)412 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
413 {
414 efi_status_t status;
415 u32 width, height;
416 void **uga_handle = NULL;
417 efi_uga_draw_protocol_t *uga = NULL, *first_uga;
418 efi_handle_t handle;
419 int i;
420
421 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
422 (void **)&uga_handle);
423 if (status != EFI_SUCCESS)
424 return status;
425
426 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
427 uga_proto, NULL, &size, uga_handle);
428 if (status != EFI_SUCCESS)
429 goto free_handle;
430
431 height = 0;
432 width = 0;
433
434 first_uga = NULL;
435 for_each_efi_handle(handle, uga_handle, size, i) {
436 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
437 u32 w, h, depth, refresh;
438 void *pciio;
439
440 status = efi_bs_call(handle_protocol, handle, uga_proto,
441 (void **)&uga);
442 if (status != EFI_SUCCESS)
443 continue;
444
445 pciio = NULL;
446 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
447
448 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
449 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
450 width = w;
451 height = h;
452
453 /*
454 * Once we've found a UGA supporting PCIIO,
455 * don't bother looking any further.
456 */
457 if (pciio)
458 break;
459
460 first_uga = uga;
461 }
462 }
463
464 if (!width && !height)
465 goto free_handle;
466
467 /* EFI framebuffer */
468 si->orig_video_isVGA = VIDEO_TYPE_EFI;
469
470 si->lfb_depth = 32;
471 si->lfb_width = width;
472 si->lfb_height = height;
473
474 si->red_size = 8;
475 si->red_pos = 16;
476 si->green_size = 8;
477 si->green_pos = 8;
478 si->blue_size = 8;
479 si->blue_pos = 0;
480 si->rsvd_size = 8;
481 si->rsvd_pos = 24;
482
483 free_handle:
484 efi_bs_call(free_pool, uga_handle);
485
486 return status;
487 }
488
setup_graphics(struct boot_params * boot_params)489 static void setup_graphics(struct boot_params *boot_params)
490 {
491 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
492 struct screen_info *si;
493 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
494 efi_status_t status;
495 unsigned long size;
496 void **gop_handle = NULL;
497 void **uga_handle = NULL;
498
499 si = &boot_params->screen_info;
500 memset(si, 0, sizeof(*si));
501
502 size = 0;
503 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
504 &graphics_proto, NULL, &size, gop_handle);
505 if (status == EFI_BUFFER_TOO_SMALL)
506 status = efi_setup_gop(si, &graphics_proto, size);
507
508 if (status != EFI_SUCCESS) {
509 size = 0;
510 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
511 &uga_proto, NULL, &size, uga_handle);
512 if (status == EFI_BUFFER_TOO_SMALL)
513 setup_uga(si, &uga_proto, size);
514 }
515 }
516
517
efi_exit(efi_handle_t handle,efi_status_t status)518 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
519 {
520 efi_bs_call(exit, handle, status, 0, NULL);
521 for(;;)
522 asm("hlt");
523 }
524
525 void __noreturn efi_stub_entry(efi_handle_t handle,
526 efi_system_table_t *sys_table_arg,
527 struct boot_params *boot_params);
528
529 /*
530 * Because the x86 boot code expects to be passed a boot_params we
531 * need to create one ourselves (usually the bootloader would create
532 * one for us).
533 */
efi_pe_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg)534 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
535 efi_system_table_t *sys_table_arg)
536 {
537 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
538 struct boot_params *boot_params;
539 struct setup_header *hdr;
540 int options_size = 0;
541 efi_status_t status;
542 unsigned long alloc;
543 char *cmdline_ptr;
544
545 efi_system_table = sys_table_arg;
546
547 /* Check if we were booted by the EFI firmware */
548 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
549 efi_exit(handle, EFI_INVALID_PARAMETER);
550
551 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
552 if (status != EFI_SUCCESS) {
553 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
554 efi_exit(handle, status);
555 }
556
557 status = efi_allocate_pages(PARAM_SIZE, &alloc, ULONG_MAX);
558 if (status != EFI_SUCCESS)
559 efi_exit(handle, status);
560
561 boot_params = memset((void *)alloc, 0x0, PARAM_SIZE);
562 hdr = &boot_params->hdr;
563
564 /* Assign the setup_header fields that the kernel actually cares about */
565 hdr->root_flags = 1;
566 hdr->vid_mode = 0xffff;
567
568 hdr->type_of_loader = 0x21;
569 hdr->initrd_addr_max = INT_MAX;
570
571 /* Convert unicode cmdline to ascii */
572 cmdline_ptr = efi_convert_cmdline(image, &options_size);
573 if (!cmdline_ptr) {
574 efi_free(PARAM_SIZE, alloc);
575 efi_exit(handle, EFI_OUT_OF_RESOURCES);
576 }
577
578 efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
579 &boot_params->ext_cmd_line_ptr);
580
581 efi_stub_entry(handle, sys_table_arg, boot_params);
582 /* not reached */
583 }
584
add_e820ext(struct boot_params * params,struct setup_data * e820ext,u32 nr_entries)585 static void add_e820ext(struct boot_params *params,
586 struct setup_data *e820ext, u32 nr_entries)
587 {
588 struct setup_data *data;
589
590 e820ext->type = SETUP_E820_EXT;
591 e820ext->len = nr_entries * sizeof(struct boot_e820_entry);
592 e820ext->next = 0;
593
594 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
595
596 while (data && data->next)
597 data = (struct setup_data *)(unsigned long)data->next;
598
599 if (data)
600 data->next = (unsigned long)e820ext;
601 else
602 params->hdr.setup_data = (unsigned long)e820ext;
603 }
604
605 static efi_status_t
setup_e820(struct boot_params * params,struct setup_data * e820ext,u32 e820ext_size)606 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
607 {
608 struct boot_e820_entry *entry = params->e820_table;
609 struct efi_info *efi = ¶ms->efi_info;
610 struct boot_e820_entry *prev = NULL;
611 u32 nr_entries;
612 u32 nr_desc;
613 int i;
614
615 nr_entries = 0;
616 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
617
618 for (i = 0; i < nr_desc; i++) {
619 efi_memory_desc_t *d;
620 unsigned int e820_type = 0;
621 unsigned long m = efi->efi_memmap;
622
623 #ifdef CONFIG_X86_64
624 m |= (u64)efi->efi_memmap_hi << 32;
625 #endif
626
627 d = efi_memdesc_ptr(m, efi->efi_memdesc_size, i);
628 switch (d->type) {
629 case EFI_RESERVED_TYPE:
630 case EFI_RUNTIME_SERVICES_CODE:
631 case EFI_RUNTIME_SERVICES_DATA:
632 case EFI_MEMORY_MAPPED_IO:
633 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
634 case EFI_PAL_CODE:
635 e820_type = E820_TYPE_RESERVED;
636 break;
637
638 case EFI_UNUSABLE_MEMORY:
639 e820_type = E820_TYPE_UNUSABLE;
640 break;
641
642 case EFI_ACPI_RECLAIM_MEMORY:
643 e820_type = E820_TYPE_ACPI;
644 break;
645
646 case EFI_LOADER_CODE:
647 case EFI_LOADER_DATA:
648 case EFI_BOOT_SERVICES_CODE:
649 case EFI_BOOT_SERVICES_DATA:
650 case EFI_CONVENTIONAL_MEMORY:
651 if (efi_soft_reserve_enabled() &&
652 (d->attribute & EFI_MEMORY_SP))
653 e820_type = E820_TYPE_SOFT_RESERVED;
654 else
655 e820_type = E820_TYPE_RAM;
656 break;
657
658 case EFI_ACPI_MEMORY_NVS:
659 e820_type = E820_TYPE_NVS;
660 break;
661
662 case EFI_PERSISTENT_MEMORY:
663 e820_type = E820_TYPE_PMEM;
664 break;
665
666 case EFI_UNACCEPTED_MEMORY:
667 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
668 continue;
669 e820_type = E820_TYPE_RAM;
670 process_unaccepted_memory(d->phys_addr,
671 d->phys_addr + PAGE_SIZE * d->num_pages);
672 break;
673 default:
674 continue;
675 }
676
677 /* Merge adjacent mappings */
678 if (prev && prev->type == e820_type &&
679 (prev->addr + prev->size) == d->phys_addr) {
680 prev->size += d->num_pages << 12;
681 continue;
682 }
683
684 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
685 u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
686 sizeof(struct setup_data);
687
688 if (!e820ext || e820ext_size < need)
689 return EFI_BUFFER_TOO_SMALL;
690
691 /* boot_params map full, switch to e820 extended */
692 entry = (struct boot_e820_entry *)e820ext->data;
693 }
694
695 entry->addr = d->phys_addr;
696 entry->size = d->num_pages << PAGE_SHIFT;
697 entry->type = e820_type;
698 prev = entry++;
699 nr_entries++;
700 }
701
702 if (nr_entries > ARRAY_SIZE(params->e820_table)) {
703 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
704
705 add_e820ext(params, e820ext, nr_e820ext);
706 nr_entries -= nr_e820ext;
707 }
708
709 params->e820_entries = (u8)nr_entries;
710
711 return EFI_SUCCESS;
712 }
713
alloc_e820ext(u32 nr_desc,struct setup_data ** e820ext,u32 * e820ext_size)714 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
715 u32 *e820ext_size)
716 {
717 efi_status_t status;
718 unsigned long size;
719
720 size = sizeof(struct setup_data) +
721 sizeof(struct e820_entry) * nr_desc;
722
723 if (*e820ext) {
724 efi_bs_call(free_pool, *e820ext);
725 *e820ext = NULL;
726 *e820ext_size = 0;
727 }
728
729 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
730 (void **)e820ext);
731 if (status == EFI_SUCCESS)
732 *e820ext_size = size;
733
734 return status;
735 }
736
allocate_e820(struct boot_params * params,struct setup_data ** e820ext,u32 * e820ext_size)737 static efi_status_t allocate_e820(struct boot_params *params,
738 struct setup_data **e820ext,
739 u32 *e820ext_size)
740 {
741 struct efi_boot_memmap *map;
742 efi_status_t status;
743 __u32 nr_desc;
744
745 status = efi_get_memory_map(&map, false);
746 if (status != EFI_SUCCESS)
747 return status;
748
749 nr_desc = map->map_size / map->desc_size;
750 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
751 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
752 EFI_MMAP_NR_SLACK_SLOTS;
753
754 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
755 }
756
757 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS)
758 status = allocate_unaccepted_bitmap(nr_desc, map);
759
760 efi_bs_call(free_pool, map);
761 return status;
762 }
763
764 struct exit_boot_struct {
765 struct boot_params *boot_params;
766 struct efi_info *efi;
767 };
768
exit_boot_func(struct efi_boot_memmap * map,void * priv)769 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
770 void *priv)
771 {
772 const char *signature;
773 struct exit_boot_struct *p = priv;
774
775 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
776 : EFI32_LOADER_SIGNATURE;
777 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
778
779 efi_set_u64_split((unsigned long)efi_system_table,
780 &p->efi->efi_systab, &p->efi->efi_systab_hi);
781 p->efi->efi_memdesc_size = map->desc_size;
782 p->efi->efi_memdesc_version = map->desc_ver;
783 efi_set_u64_split((unsigned long)map->map,
784 &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
785 p->efi->efi_memmap_size = map->map_size;
786
787 return EFI_SUCCESS;
788 }
789
exit_boot(struct boot_params * boot_params,void * handle)790 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
791 {
792 struct setup_data *e820ext = NULL;
793 __u32 e820ext_size = 0;
794 efi_status_t status;
795 struct exit_boot_struct priv;
796
797 priv.boot_params = boot_params;
798 priv.efi = &boot_params->efi_info;
799
800 status = allocate_e820(boot_params, &e820ext, &e820ext_size);
801 if (status != EFI_SUCCESS)
802 return status;
803
804 /* Might as well exit boot services now */
805 status = efi_exit_boot_services(handle, &priv, exit_boot_func);
806 if (status != EFI_SUCCESS)
807 return status;
808
809 /* Historic? */
810 boot_params->alt_mem_k = 32 * 1024;
811
812 status = setup_e820(boot_params, e820ext, e820ext_size);
813 if (status != EFI_SUCCESS)
814 return status;
815
816 return EFI_SUCCESS;
817 }
818
have_unsupported_snp_features(void)819 static bool have_unsupported_snp_features(void)
820 {
821 u64 unsupported;
822
823 unsupported = snp_get_unsupported_features(sev_get_status());
824 if (unsupported) {
825 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
826 unsupported);
827 return true;
828 }
829 return false;
830 }
831
efi_get_seed(void * seed,int size)832 static void efi_get_seed(void *seed, int size)
833 {
834 efi_get_random_bytes(size, seed);
835
836 /*
837 * This only updates seed[0] when running on 32-bit, but in that case,
838 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
839 */
840 *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
841 }
842
error(char * str)843 static void error(char *str)
844 {
845 efi_warn("Decompression failed: %s\n", str);
846 }
847
848 static const char *cmdline_memmap_override;
849
parse_options(const char * cmdline)850 static efi_status_t parse_options(const char *cmdline)
851 {
852 static const char opts[][14] = {
853 "mem=", "memmap=", "hugepages="
854 };
855
856 for (int i = 0; i < ARRAY_SIZE(opts); i++) {
857 const char *p = strstr(cmdline, opts[i]);
858
859 if (p == cmdline || (p > cmdline && isspace(p[-1]))) {
860 cmdline_memmap_override = opts[i];
861 break;
862 }
863 }
864
865 return efi_parse_options(cmdline);
866 }
867
efi_decompress_kernel(unsigned long * kernel_entry)868 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
869 {
870 unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
871 unsigned long addr, alloc_size, entry;
872 efi_status_t status;
873 u32 seed[2] = {};
874
875 /* determine the required size of the allocation */
876 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
877 MIN_KERNEL_ALIGN);
878
879 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
880 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
881 static const efi_char16_t ami[] = L"American Megatrends";
882
883 efi_get_seed(seed, sizeof(seed));
884
885 virt_addr += (range * seed[1]) >> 32;
886 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
887
888 /*
889 * Older Dell systems with AMI UEFI firmware v2.0 may hang
890 * while decompressing the kernel if physical address
891 * randomization is enabled.
892 *
893 * https://bugzilla.kernel.org/show_bug.cgi?id=218173
894 */
895 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
896 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
897 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
898 seed[0] = 0;
899 } else if (cmdline_memmap_override) {
900 efi_info("%s detected on the kernel command line - disabling physical KASLR\n",
901 cmdline_memmap_override);
902 seed[0] = 0;
903 }
904
905 boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
906 }
907
908 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
909 seed[0], EFI_LOADER_CODE,
910 LOAD_PHYSICAL_ADDR,
911 EFI_X86_KERNEL_ALLOC_LIMIT);
912 if (status != EFI_SUCCESS)
913 return status;
914
915 entry = decompress_kernel((void *)addr, virt_addr, error);
916 if (entry == ULONG_MAX) {
917 efi_free(alloc_size, addr);
918 return EFI_LOAD_ERROR;
919 }
920
921 *kernel_entry = addr + entry;
922
923 return efi_adjust_memory_range_protection(addr, kernel_text_size);
924 }
925
enter_kernel(unsigned long kernel_addr,struct boot_params * boot_params)926 static void __noreturn enter_kernel(unsigned long kernel_addr,
927 struct boot_params *boot_params)
928 {
929 /* enter decompressed kernel with boot_params pointer in RSI/ESI */
930 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
931
932 unreachable();
933 }
934
935 /*
936 * On success, this routine will jump to the relocated image directly and never
937 * return. On failure, it will exit to the firmware via efi_exit() instead of
938 * returning.
939 */
efi_stub_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg,struct boot_params * boot_params)940 void __noreturn efi_stub_entry(efi_handle_t handle,
941 efi_system_table_t *sys_table_arg,
942 struct boot_params *boot_params)
943 {
944 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
945 struct setup_header *hdr = &boot_params->hdr;
946 const struct linux_efi_initrd *initrd = NULL;
947 unsigned long kernel_entry;
948 efi_status_t status;
949
950 boot_params_ptr = boot_params;
951
952 efi_system_table = sys_table_arg;
953 /* Check if we were booted by the EFI firmware */
954 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
955 efi_exit(handle, EFI_INVALID_PARAMETER);
956
957 if (have_unsupported_snp_features())
958 efi_exit(handle, EFI_UNSUPPORTED);
959
960 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
961 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
962 if (efi_dxe_table &&
963 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
964 efi_warn("Ignoring DXE services table: invalid signature\n");
965 efi_dxe_table = NULL;
966 }
967 }
968
969 /* grab the memory attributes protocol if it exists */
970 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
971
972 status = efi_setup_5level_paging();
973 if (status != EFI_SUCCESS) {
974 efi_err("efi_setup_5level_paging() failed!\n");
975 goto fail;
976 }
977
978 #ifdef CONFIG_CMDLINE_BOOL
979 status = parse_options(CONFIG_CMDLINE);
980 if (status != EFI_SUCCESS) {
981 efi_err("Failed to parse options\n");
982 goto fail;
983 }
984 #endif
985 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
986 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
987 ((u64)boot_params->ext_cmd_line_ptr << 32));
988 status = parse_options((char *)cmdline_paddr);
989 if (status != EFI_SUCCESS) {
990 efi_err("Failed to parse options\n");
991 goto fail;
992 }
993 }
994
995 if (efi_mem_encrypt > 0)
996 hdr->xloadflags |= XLF_MEM_ENCRYPTION;
997
998 status = efi_decompress_kernel(&kernel_entry);
999 if (status != EFI_SUCCESS) {
1000 efi_err("Failed to decompress kernel\n");
1001 goto fail;
1002 }
1003
1004 /*
1005 * At this point, an initrd may already have been loaded by the
1006 * bootloader and passed via bootparams. We permit an initrd loaded
1007 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
1008 *
1009 * If the device path is not present, any command-line initrd=
1010 * arguments will be processed only if image is not NULL, which will be
1011 * the case only if we were loaded via the PE entry point.
1012 */
1013 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
1014 &initrd);
1015 if (status != EFI_SUCCESS)
1016 goto fail;
1017 if (initrd && initrd->size > 0) {
1018 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
1019 &boot_params->ext_ramdisk_image);
1020 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
1021 &boot_params->ext_ramdisk_size);
1022 }
1023
1024
1025 /*
1026 * If the boot loader gave us a value for secure_boot then we use that,
1027 * otherwise we ask the BIOS.
1028 */
1029 if (boot_params->secure_boot == efi_secureboot_mode_unset)
1030 boot_params->secure_boot = efi_get_secureboot();
1031
1032 /* Ask the firmware to clear memory on unclean shutdown */
1033 efi_enable_reset_attack_mitigation();
1034
1035 efi_random_get_seed();
1036
1037 efi_retrieve_eventlog();
1038
1039 setup_graphics(boot_params);
1040
1041 setup_efi_pci(boot_params);
1042
1043 setup_quirks(boot_params);
1044
1045 setup_unaccepted_memory();
1046
1047 status = exit_boot(boot_params, handle);
1048 if (status != EFI_SUCCESS) {
1049 efi_err("exit_boot() failed!\n");
1050 goto fail;
1051 }
1052
1053 /*
1054 * Call the SEV init code while still running with the firmware's
1055 * GDT/IDT, so #VC exceptions will be handled by EFI.
1056 */
1057 sev_enable(boot_params);
1058
1059 efi_5level_switch();
1060
1061 enter_kernel(kernel_entry, boot_params);
1062 fail:
1063 efi_err("efi_stub_entry() failed!\n");
1064
1065 efi_exit(handle, status);
1066 }
1067
1068 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
efi_handover_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg,struct boot_params * boot_params)1069 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1070 struct boot_params *boot_params)
1071 {
1072 memset(_bss, 0, _ebss - _bss);
1073 efi_stub_entry(handle, sys_table_arg, boot_params);
1074 }
1075
1076 #ifndef CONFIG_EFI_MIXED
1077 extern __alias(efi_handover_entry)
1078 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1079 struct boot_params *boot_params);
1080
1081 extern __alias(efi_handover_entry)
1082 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1083 struct boot_params *boot_params);
1084 #endif
1085 #endif
1086