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
efi_adjust_memory_range_protection(unsigned long start,unsigned long size)228 efi_status_t efi_adjust_memory_range_protection(unsigned long start,
229 unsigned long size)
230 {
231 efi_status_t status;
232 efi_gcd_memory_space_desc_t desc;
233 unsigned long end, next;
234 unsigned long rounded_start, rounded_end;
235 unsigned long unprotect_start, unprotect_size;
236
237 rounded_start = rounddown(start, EFI_PAGE_SIZE);
238 rounded_end = roundup(start + size, EFI_PAGE_SIZE);
239
240 if (memattr != NULL) {
241 status = efi_call_proto(memattr, set_memory_attributes,
242 rounded_start,
243 rounded_end - rounded_start,
244 EFI_MEMORY_RO);
245 if (status != EFI_SUCCESS) {
246 efi_warn("Failed to set EFI_MEMORY_RO attribute\n");
247 return status;
248 }
249
250 status = efi_call_proto(memattr, clear_memory_attributes,
251 rounded_start,
252 rounded_end - rounded_start,
253 EFI_MEMORY_XP);
254 if (status != EFI_SUCCESS)
255 efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
256 return status;
257 }
258
259 if (efi_dxe_table == NULL)
260 return EFI_SUCCESS;
261
262 /*
263 * Don't modify memory region attributes, they are
264 * already suitable, to lower the possibility to
265 * encounter firmware bugs.
266 */
267
268 for (end = start + size; start < end; start = next) {
269
270 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
271
272 if (status != EFI_SUCCESS)
273 break;
274
275 next = desc.base_address + desc.length;
276
277 /*
278 * Only system memory is suitable for trampoline/kernel image placement,
279 * so only this type of memory needs its attributes to be modified.
280 */
281
282 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
283 (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
284 continue;
285
286 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
287 unprotect_size = min(rounded_end, next) - unprotect_start;
288
289 status = efi_dxe_call(set_memory_space_attributes,
290 unprotect_start, unprotect_size,
291 EFI_MEMORY_WB);
292
293 if (status != EFI_SUCCESS) {
294 efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
295 unprotect_start,
296 unprotect_start + unprotect_size,
297 status);
298 break;
299 }
300 }
301 return EFI_SUCCESS;
302 }
303
setup_unaccepted_memory(void)304 static void setup_unaccepted_memory(void)
305 {
306 efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
307 sev_memory_acceptance_protocol_t *proto;
308 efi_status_t status;
309
310 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
311 return;
312
313 /*
314 * Enable unaccepted memory before calling exit boot services in order
315 * for the UEFI to not accept all memory on EBS.
316 */
317 status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
318 (void **)&proto);
319 if (status != EFI_SUCCESS)
320 return;
321
322 status = efi_call_proto(proto, allow_unaccepted_memory);
323 if (status != EFI_SUCCESS)
324 efi_err("Memory acceptance protocol failed\n");
325 }
326
efistub_fw_vendor(void)327 static efi_char16_t *efistub_fw_vendor(void)
328 {
329 unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
330
331 return (efi_char16_t *)vendor;
332 }
333
334 static const efi_char16_t apple[] = L"Apple";
335
setup_quirks(struct boot_params * boot_params)336 static void setup_quirks(struct boot_params *boot_params)
337 {
338 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) &&
339 !memcmp(efistub_fw_vendor(), apple, sizeof(apple)))
340 retrieve_apple_device_properties(boot_params);
341 }
342
343 /*
344 * See if we have Universal Graphics Adapter (UGA) protocol
345 */
346 static efi_status_t
setup_uga(struct screen_info * si,efi_guid_t * uga_proto,unsigned long size)347 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
348 {
349 efi_status_t status;
350 u32 width, height;
351 void **uga_handle = NULL;
352 efi_uga_draw_protocol_t *uga = NULL, *first_uga;
353 efi_handle_t handle;
354 int i;
355
356 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
357 (void **)&uga_handle);
358 if (status != EFI_SUCCESS)
359 return status;
360
361 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
362 uga_proto, NULL, &size, uga_handle);
363 if (status != EFI_SUCCESS)
364 goto free_handle;
365
366 height = 0;
367 width = 0;
368
369 first_uga = NULL;
370 for_each_efi_handle(handle, uga_handle, size, i) {
371 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
372 u32 w, h, depth, refresh;
373 void *pciio;
374
375 status = efi_bs_call(handle_protocol, handle, uga_proto,
376 (void **)&uga);
377 if (status != EFI_SUCCESS)
378 continue;
379
380 pciio = NULL;
381 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
382
383 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
384 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
385 width = w;
386 height = h;
387
388 /*
389 * Once we've found a UGA supporting PCIIO,
390 * don't bother looking any further.
391 */
392 if (pciio)
393 break;
394
395 first_uga = uga;
396 }
397 }
398
399 if (!width && !height)
400 goto free_handle;
401
402 /* EFI framebuffer */
403 si->orig_video_isVGA = VIDEO_TYPE_EFI;
404
405 si->lfb_depth = 32;
406 si->lfb_width = width;
407 si->lfb_height = height;
408
409 si->red_size = 8;
410 si->red_pos = 16;
411 si->green_size = 8;
412 si->green_pos = 8;
413 si->blue_size = 8;
414 si->blue_pos = 0;
415 si->rsvd_size = 8;
416 si->rsvd_pos = 24;
417
418 free_handle:
419 efi_bs_call(free_pool, uga_handle);
420
421 return status;
422 }
423
setup_graphics(struct boot_params * boot_params)424 static void setup_graphics(struct boot_params *boot_params)
425 {
426 efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
427 struct screen_info *si;
428 efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
429 efi_status_t status;
430 unsigned long size;
431 void **gop_handle = NULL;
432 void **uga_handle = NULL;
433
434 si = &boot_params->screen_info;
435 memset(si, 0, sizeof(*si));
436
437 size = 0;
438 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
439 &graphics_proto, NULL, &size, gop_handle);
440 if (status == EFI_BUFFER_TOO_SMALL)
441 status = efi_setup_gop(si, &graphics_proto, size);
442
443 if (status != EFI_SUCCESS) {
444 size = 0;
445 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
446 &uga_proto, NULL, &size, uga_handle);
447 if (status == EFI_BUFFER_TOO_SMALL)
448 setup_uga(si, &uga_proto, size);
449 }
450 }
451
452
efi_exit(efi_handle_t handle,efi_status_t status)453 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
454 {
455 efi_bs_call(exit, handle, status, 0, NULL);
456 for(;;)
457 asm("hlt");
458 }
459
460 void __noreturn efi_stub_entry(efi_handle_t handle,
461 efi_system_table_t *sys_table_arg,
462 struct boot_params *boot_params);
463
464 /*
465 * Because the x86 boot code expects to be passed a boot_params we
466 * need to create one ourselves (usually the bootloader would create
467 * one for us).
468 */
efi_pe_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg)469 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
470 efi_system_table_t *sys_table_arg)
471 {
472 efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
473 struct boot_params *boot_params;
474 struct setup_header *hdr;
475 int options_size = 0;
476 efi_status_t status;
477 unsigned long alloc;
478 char *cmdline_ptr;
479
480 if (efi_is_native())
481 memset(_bss, 0, _ebss - _bss);
482
483 efi_system_table = sys_table_arg;
484
485 /* Check if we were booted by the EFI firmware */
486 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
487 efi_exit(handle, EFI_INVALID_PARAMETER);
488
489 status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
490 if (status != EFI_SUCCESS) {
491 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
492 efi_exit(handle, status);
493 }
494
495 status = efi_allocate_pages(PARAM_SIZE, &alloc, ULONG_MAX);
496 if (status != EFI_SUCCESS)
497 efi_exit(handle, status);
498
499 boot_params = memset((void *)alloc, 0x0, PARAM_SIZE);
500 hdr = &boot_params->hdr;
501
502 /* Assign the setup_header fields that the kernel actually cares about */
503 hdr->root_flags = 1;
504 hdr->vid_mode = 0xffff;
505
506 hdr->type_of_loader = 0x21;
507 hdr->initrd_addr_max = INT_MAX;
508
509 /* Convert unicode cmdline to ascii */
510 cmdline_ptr = efi_convert_cmdline(image, &options_size);
511 if (!cmdline_ptr) {
512 efi_free(PARAM_SIZE, alloc);
513 efi_exit(handle, EFI_OUT_OF_RESOURCES);
514 }
515
516 efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
517 &boot_params->ext_cmd_line_ptr);
518
519 efi_stub_entry(handle, sys_table_arg, boot_params);
520 /* not reached */
521 }
522
add_e820ext(struct boot_params * params,struct setup_data * e820ext,u32 nr_entries)523 static void add_e820ext(struct boot_params *params,
524 struct setup_data *e820ext, u32 nr_entries)
525 {
526 struct setup_data *data;
527
528 e820ext->type = SETUP_E820_EXT;
529 e820ext->len = nr_entries * sizeof(struct boot_e820_entry);
530 e820ext->next = 0;
531
532 data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
533
534 while (data && data->next)
535 data = (struct setup_data *)(unsigned long)data->next;
536
537 if (data)
538 data->next = (unsigned long)e820ext;
539 else
540 params->hdr.setup_data = (unsigned long)e820ext;
541 }
542
543 static efi_status_t
setup_e820(struct boot_params * params,struct setup_data * e820ext,u32 e820ext_size)544 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
545 {
546 struct boot_e820_entry *entry = params->e820_table;
547 struct efi_info *efi = ¶ms->efi_info;
548 struct boot_e820_entry *prev = NULL;
549 u32 nr_entries;
550 u32 nr_desc;
551 int i;
552
553 nr_entries = 0;
554 nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
555
556 for (i = 0; i < nr_desc; i++) {
557 efi_memory_desc_t *d;
558 unsigned int e820_type = 0;
559 unsigned long m = efi->efi_memmap;
560
561 #ifdef CONFIG_X86_64
562 m |= (u64)efi->efi_memmap_hi << 32;
563 #endif
564
565 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
566 switch (d->type) {
567 case EFI_RESERVED_TYPE:
568 case EFI_RUNTIME_SERVICES_CODE:
569 case EFI_RUNTIME_SERVICES_DATA:
570 case EFI_MEMORY_MAPPED_IO:
571 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
572 case EFI_PAL_CODE:
573 e820_type = E820_TYPE_RESERVED;
574 break;
575
576 case EFI_UNUSABLE_MEMORY:
577 e820_type = E820_TYPE_UNUSABLE;
578 break;
579
580 case EFI_ACPI_RECLAIM_MEMORY:
581 e820_type = E820_TYPE_ACPI;
582 break;
583
584 case EFI_LOADER_CODE:
585 case EFI_LOADER_DATA:
586 case EFI_BOOT_SERVICES_CODE:
587 case EFI_BOOT_SERVICES_DATA:
588 case EFI_CONVENTIONAL_MEMORY:
589 if (efi_soft_reserve_enabled() &&
590 (d->attribute & EFI_MEMORY_SP))
591 e820_type = E820_TYPE_SOFT_RESERVED;
592 else
593 e820_type = E820_TYPE_RAM;
594 break;
595
596 case EFI_ACPI_MEMORY_NVS:
597 e820_type = E820_TYPE_NVS;
598 break;
599
600 case EFI_PERSISTENT_MEMORY:
601 e820_type = E820_TYPE_PMEM;
602 break;
603
604 case EFI_UNACCEPTED_MEMORY:
605 if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
606 continue;
607 e820_type = E820_TYPE_RAM;
608 process_unaccepted_memory(d->phys_addr,
609 d->phys_addr + PAGE_SIZE * d->num_pages);
610 break;
611 default:
612 continue;
613 }
614
615 /* Merge adjacent mappings */
616 if (prev && prev->type == e820_type &&
617 (prev->addr + prev->size) == d->phys_addr) {
618 prev->size += d->num_pages << 12;
619 continue;
620 }
621
622 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
623 u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
624 sizeof(struct setup_data);
625
626 if (!e820ext || e820ext_size < need)
627 return EFI_BUFFER_TOO_SMALL;
628
629 /* boot_params map full, switch to e820 extended */
630 entry = (struct boot_e820_entry *)e820ext->data;
631 }
632
633 entry->addr = d->phys_addr;
634 entry->size = d->num_pages << PAGE_SHIFT;
635 entry->type = e820_type;
636 prev = entry++;
637 nr_entries++;
638 }
639
640 if (nr_entries > ARRAY_SIZE(params->e820_table)) {
641 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
642
643 add_e820ext(params, e820ext, nr_e820ext);
644 nr_entries -= nr_e820ext;
645 }
646
647 params->e820_entries = (u8)nr_entries;
648
649 return EFI_SUCCESS;
650 }
651
alloc_e820ext(u32 nr_desc,struct setup_data ** e820ext,u32 * e820ext_size)652 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
653 u32 *e820ext_size)
654 {
655 efi_status_t status;
656 unsigned long size;
657
658 size = sizeof(struct setup_data) +
659 sizeof(struct e820_entry) * nr_desc;
660
661 if (*e820ext) {
662 efi_bs_call(free_pool, *e820ext);
663 *e820ext = NULL;
664 *e820ext_size = 0;
665 }
666
667 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
668 (void **)e820ext);
669 if (status == EFI_SUCCESS)
670 *e820ext_size = size;
671
672 return status;
673 }
674
allocate_e820(struct boot_params * params,struct setup_data ** e820ext,u32 * e820ext_size)675 static efi_status_t allocate_e820(struct boot_params *params,
676 struct setup_data **e820ext,
677 u32 *e820ext_size)
678 {
679 struct efi_boot_memmap *map;
680 efi_status_t status;
681 __u32 nr_desc;
682
683 status = efi_get_memory_map(&map, false);
684 if (status != EFI_SUCCESS)
685 return status;
686
687 nr_desc = map->map_size / map->desc_size;
688 if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
689 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
690 EFI_MMAP_NR_SLACK_SLOTS;
691
692 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
693 }
694
695 if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS)
696 status = allocate_unaccepted_bitmap(nr_desc, map);
697
698 efi_bs_call(free_pool, map);
699 return status;
700 }
701
702 struct exit_boot_struct {
703 struct boot_params *boot_params;
704 struct efi_info *efi;
705 };
706
exit_boot_func(struct efi_boot_memmap * map,void * priv)707 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
708 void *priv)
709 {
710 const char *signature;
711 struct exit_boot_struct *p = priv;
712
713 signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
714 : EFI32_LOADER_SIGNATURE;
715 memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
716
717 efi_set_u64_split((unsigned long)efi_system_table,
718 &p->efi->efi_systab, &p->efi->efi_systab_hi);
719 p->efi->efi_memdesc_size = map->desc_size;
720 p->efi->efi_memdesc_version = map->desc_ver;
721 efi_set_u64_split((unsigned long)map->map,
722 &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
723 p->efi->efi_memmap_size = map->map_size;
724
725 return EFI_SUCCESS;
726 }
727
exit_boot(struct boot_params * boot_params,void * handle)728 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
729 {
730 struct setup_data *e820ext = NULL;
731 __u32 e820ext_size = 0;
732 efi_status_t status;
733 struct exit_boot_struct priv;
734
735 priv.boot_params = boot_params;
736 priv.efi = &boot_params->efi_info;
737
738 status = allocate_e820(boot_params, &e820ext, &e820ext_size);
739 if (status != EFI_SUCCESS)
740 return status;
741
742 /* Might as well exit boot services now */
743 status = efi_exit_boot_services(handle, &priv, exit_boot_func);
744 if (status != EFI_SUCCESS)
745 return status;
746
747 /* Historic? */
748 boot_params->alt_mem_k = 32 * 1024;
749
750 status = setup_e820(boot_params, e820ext, e820ext_size);
751 if (status != EFI_SUCCESS)
752 return status;
753
754 return EFI_SUCCESS;
755 }
756
have_unsupported_snp_features(void)757 static bool have_unsupported_snp_features(void)
758 {
759 u64 unsupported;
760
761 unsupported = snp_get_unsupported_features(sev_get_status());
762 if (unsupported) {
763 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
764 unsupported);
765 return true;
766 }
767 return false;
768 }
769
efi_get_seed(void * seed,int size)770 static void efi_get_seed(void *seed, int size)
771 {
772 efi_get_random_bytes(size, seed);
773
774 /*
775 * This only updates seed[0] when running on 32-bit, but in that case,
776 * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
777 */
778 *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
779 }
780
error(char * str)781 static void error(char *str)
782 {
783 efi_warn("Decompression failed: %s\n", str);
784 }
785
786 static const char *cmdline_memmap_override;
787
parse_options(const char * cmdline)788 static efi_status_t parse_options(const char *cmdline)
789 {
790 static const char opts[][14] = {
791 "mem=", "memmap=", "efi_fake_mem=", "hugepages="
792 };
793
794 for (int i = 0; i < ARRAY_SIZE(opts); i++) {
795 const char *p = strstr(cmdline, opts[i]);
796
797 if (p == cmdline || (p > cmdline && isspace(p[-1]))) {
798 cmdline_memmap_override = opts[i];
799 break;
800 }
801 }
802
803 return efi_parse_options(cmdline);
804 }
805
efi_decompress_kernel(unsigned long * kernel_entry)806 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
807 {
808 unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
809 unsigned long addr, alloc_size, entry;
810 efi_status_t status;
811 u32 seed[2] = {};
812
813 /* determine the required size of the allocation */
814 alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
815 MIN_KERNEL_ALIGN);
816
817 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
818 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
819 static const efi_char16_t ami[] = L"American Megatrends";
820
821 efi_get_seed(seed, sizeof(seed));
822
823 virt_addr += (range * seed[1]) >> 32;
824 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
825
826 /*
827 * Older Dell systems with AMI UEFI firmware v2.0 may hang
828 * while decompressing the kernel if physical address
829 * randomization is enabled.
830 *
831 * https://bugzilla.kernel.org/show_bug.cgi?id=218173
832 */
833 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
834 !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
835 efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
836 seed[0] = 0;
837 } else if (cmdline_memmap_override) {
838 efi_info("%s detected on the kernel command line - disabling physical KASLR\n",
839 cmdline_memmap_override);
840 seed[0] = 0;
841 }
842 }
843
844 status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
845 seed[0], EFI_LOADER_CODE,
846 LOAD_PHYSICAL_ADDR,
847 EFI_X86_KERNEL_ALLOC_LIMIT);
848 if (status != EFI_SUCCESS)
849 return status;
850
851 entry = decompress_kernel((void *)addr, virt_addr, error);
852 if (entry == ULONG_MAX) {
853 efi_free(alloc_size, addr);
854 return EFI_LOAD_ERROR;
855 }
856
857 *kernel_entry = addr + entry;
858
859 return efi_adjust_memory_range_protection(addr, kernel_text_size);
860 }
861
enter_kernel(unsigned long kernel_addr,struct boot_params * boot_params)862 static void __noreturn enter_kernel(unsigned long kernel_addr,
863 struct boot_params *boot_params)
864 {
865 /* enter decompressed kernel with boot_params pointer in RSI/ESI */
866 asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
867
868 unreachable();
869 }
870
871 /*
872 * On success, this routine will jump to the relocated image directly and never
873 * return. On failure, it will exit to the firmware via efi_exit() instead of
874 * returning.
875 */
efi_stub_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg,struct boot_params * boot_params)876 void __noreturn efi_stub_entry(efi_handle_t handle,
877 efi_system_table_t *sys_table_arg,
878 struct boot_params *boot_params)
879 {
880 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
881 struct setup_header *hdr = &boot_params->hdr;
882 const struct linux_efi_initrd *initrd = NULL;
883 unsigned long kernel_entry;
884 efi_status_t status;
885
886 boot_params_pointer = boot_params;
887
888 efi_system_table = sys_table_arg;
889 /* Check if we were booted by the EFI firmware */
890 if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
891 efi_exit(handle, EFI_INVALID_PARAMETER);
892
893 if (have_unsupported_snp_features())
894 efi_exit(handle, EFI_UNSUPPORTED);
895
896 if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
897 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
898 if (efi_dxe_table &&
899 efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
900 efi_warn("Ignoring DXE services table: invalid signature\n");
901 efi_dxe_table = NULL;
902 }
903 }
904
905 /* grab the memory attributes protocol if it exists */
906 efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
907
908 status = efi_setup_5level_paging();
909 if (status != EFI_SUCCESS) {
910 efi_err("efi_setup_5level_paging() failed!\n");
911 goto fail;
912 }
913
914 #ifdef CONFIG_CMDLINE_BOOL
915 status = parse_options(CONFIG_CMDLINE);
916 if (status != EFI_SUCCESS) {
917 efi_err("Failed to parse options\n");
918 goto fail;
919 }
920 #endif
921 if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
922 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
923 ((u64)boot_params->ext_cmd_line_ptr << 32));
924 status = parse_options((char *)cmdline_paddr);
925 if (status != EFI_SUCCESS) {
926 efi_err("Failed to parse options\n");
927 goto fail;
928 }
929 }
930
931 if (efi_mem_encrypt > 0)
932 hdr->xloadflags |= XLF_MEM_ENCRYPTION;
933
934 status = efi_decompress_kernel(&kernel_entry);
935 if (status != EFI_SUCCESS) {
936 efi_err("Failed to decompress kernel\n");
937 goto fail;
938 }
939
940 /*
941 * At this point, an initrd may already have been loaded by the
942 * bootloader and passed via bootparams. We permit an initrd loaded
943 * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
944 *
945 * If the device path is not present, any command-line initrd=
946 * arguments will be processed only if image is not NULL, which will be
947 * the case only if we were loaded via the PE entry point.
948 */
949 status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
950 &initrd);
951 if (status != EFI_SUCCESS)
952 goto fail;
953 if (initrd && initrd->size > 0) {
954 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
955 &boot_params->ext_ramdisk_image);
956 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
957 &boot_params->ext_ramdisk_size);
958 }
959
960
961 /*
962 * If the boot loader gave us a value for secure_boot then we use that,
963 * otherwise we ask the BIOS.
964 */
965 if (boot_params->secure_boot == efi_secureboot_mode_unset)
966 boot_params->secure_boot = efi_get_secureboot();
967
968 /* Ask the firmware to clear memory on unclean shutdown */
969 efi_enable_reset_attack_mitigation();
970
971 efi_random_get_seed();
972
973 efi_retrieve_tpm2_eventlog();
974
975 setup_graphics(boot_params);
976
977 setup_efi_pci(boot_params);
978
979 setup_quirks(boot_params);
980
981 setup_unaccepted_memory();
982
983 status = exit_boot(boot_params, handle);
984 if (status != EFI_SUCCESS) {
985 efi_err("exit_boot() failed!\n");
986 goto fail;
987 }
988
989 /*
990 * Call the SEV init code while still running with the firmware's
991 * GDT/IDT, so #VC exceptions will be handled by EFI.
992 */
993 sev_enable(boot_params);
994
995 efi_5level_switch();
996
997 enter_kernel(kernel_entry, boot_params);
998 fail:
999 efi_err("efi_stub_entry() failed!\n");
1000
1001 efi_exit(handle, status);
1002 }
1003
1004 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
efi_handover_entry(efi_handle_t handle,efi_system_table_t * sys_table_arg,struct boot_params * boot_params)1005 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1006 struct boot_params *boot_params)
1007 {
1008 memset(_bss, 0, _ebss - _bss);
1009 efi_stub_entry(handle, sys_table_arg, boot_params);
1010 }
1011
1012 #ifndef CONFIG_EFI_MIXED
1013 extern __alias(efi_handover_entry)
1014 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1015 struct boot_params *boot_params);
1016
1017 extern __alias(efi_handover_entry)
1018 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1019 struct boot_params *boot_params);
1020 #endif
1021 #endif
1022