x86/efistub: Give up if memory attribute protocol returns an error
[sfrench/cifs-2.6.git] / drivers / firmware / efi / libstub / x86-stub.c
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 const efi_system_table_t *efi_system_table;
25 const efi_dxe_services_table_t *efi_dxe_table;
26 static efi_loaded_image_t *image = NULL;
27 static efi_memory_attribute_protocol_t *memattr;
28
29 typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t;
30 union sev_memory_acceptance_protocol {
31         struct {
32                 efi_status_t (__efiapi * allow_unaccepted_memory)(
33                         sev_memory_acceptance_protocol_t *);
34         };
35         struct {
36                 u32 allow_unaccepted_memory;
37         } mixed_mode;
38 };
39
40 static efi_status_t
41 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
42 {
43         struct pci_setup_rom *rom = NULL;
44         efi_status_t status;
45         unsigned long size;
46         uint64_t romsize;
47         void *romimage;
48
49         /*
50          * Some firmware images contain EFI function pointers at the place where
51          * the romimage and romsize fields are supposed to be. Typically the EFI
52          * code is mapped at high addresses, translating to an unrealistically
53          * large romsize. The UEFI spec limits the size of option ROMs to 16
54          * MiB so we reject any ROMs over 16 MiB in size to catch this.
55          */
56         romimage = efi_table_attr(pci, romimage);
57         romsize = efi_table_attr(pci, romsize);
58         if (!romimage || !romsize || romsize > SZ_16M)
59                 return EFI_INVALID_PARAMETER;
60
61         size = romsize + sizeof(*rom);
62
63         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
64                              (void **)&rom);
65         if (status != EFI_SUCCESS) {
66                 efi_err("Failed to allocate memory for 'rom'\n");
67                 return status;
68         }
69
70         memset(rom, 0, sizeof(*rom));
71
72         rom->data.type  = SETUP_PCI;
73         rom->data.len   = size - sizeof(struct setup_data);
74         rom->data.next  = 0;
75         rom->pcilen     = romsize;
76         *__rom = rom;
77
78         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
79                                 PCI_VENDOR_ID, 1, &rom->vendor);
80
81         if (status != EFI_SUCCESS) {
82                 efi_err("Failed to read rom->vendor\n");
83                 goto free_struct;
84         }
85
86         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
87                                 PCI_DEVICE_ID, 1, &rom->devid);
88
89         if (status != EFI_SUCCESS) {
90                 efi_err("Failed to read rom->devid\n");
91                 goto free_struct;
92         }
93
94         status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
95                                 &rom->device, &rom->function);
96
97         if (status != EFI_SUCCESS)
98                 goto free_struct;
99
100         memcpy(rom->romdata, romimage, romsize);
101         return status;
102
103 free_struct:
104         efi_bs_call(free_pool, rom);
105         return status;
106 }
107
108 /*
109  * There's no way to return an informative status from this function,
110  * because any analysis (and printing of error messages) needs to be
111  * done directly at the EFI function call-site.
112  *
113  * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
114  * just didn't find any PCI devices, but there's no way to tell outside
115  * the context of the call.
116  */
117 static void setup_efi_pci(struct boot_params *params)
118 {
119         efi_status_t status;
120         void **pci_handle = NULL;
121         efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
122         unsigned long size = 0;
123         struct setup_data *data;
124         efi_handle_t h;
125         int i;
126
127         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
128                              &pci_proto, NULL, &size, pci_handle);
129
130         if (status == EFI_BUFFER_TOO_SMALL) {
131                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
132                                      (void **)&pci_handle);
133
134                 if (status != EFI_SUCCESS) {
135                         efi_err("Failed to allocate memory for 'pci_handle'\n");
136                         return;
137                 }
138
139                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
140                                      &pci_proto, NULL, &size, pci_handle);
141         }
142
143         if (status != EFI_SUCCESS)
144                 goto free_handle;
145
146         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
147
148         while (data && data->next)
149                 data = (struct setup_data *)(unsigned long)data->next;
150
151         for_each_efi_handle(h, pci_handle, size, i) {
152                 efi_pci_io_protocol_t *pci = NULL;
153                 struct pci_setup_rom *rom;
154
155                 status = efi_bs_call(handle_protocol, h, &pci_proto,
156                                      (void **)&pci);
157                 if (status != EFI_SUCCESS || !pci)
158                         continue;
159
160                 status = preserve_pci_rom_image(pci, &rom);
161                 if (status != EFI_SUCCESS)
162                         continue;
163
164                 if (data)
165                         data->next = (unsigned long)rom;
166                 else
167                         params->hdr.setup_data = (unsigned long)rom;
168
169                 data = (struct setup_data *)rom;
170         }
171
172 free_handle:
173         efi_bs_call(free_pool, pci_handle);
174 }
175
176 static void retrieve_apple_device_properties(struct boot_params *boot_params)
177 {
178         efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
179         struct setup_data *data, *new;
180         efi_status_t status;
181         u32 size = 0;
182         apple_properties_protocol_t *p;
183
184         status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
185         if (status != EFI_SUCCESS)
186                 return;
187
188         if (efi_table_attr(p, version) != 0x10000) {
189                 efi_err("Unsupported properties proto version\n");
190                 return;
191         }
192
193         efi_call_proto(p, get_all, NULL, &size);
194         if (!size)
195                 return;
196
197         do {
198                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
199                                      size + sizeof(struct setup_data),
200                                      (void **)&new);
201                 if (status != EFI_SUCCESS) {
202                         efi_err("Failed to allocate memory for 'properties'\n");
203                         return;
204                 }
205
206                 status = efi_call_proto(p, get_all, new->data, &size);
207
208                 if (status == EFI_BUFFER_TOO_SMALL)
209                         efi_bs_call(free_pool, new);
210         } while (status == EFI_BUFFER_TOO_SMALL);
211
212         new->type = SETUP_APPLE_PROPERTIES;
213         new->len  = size;
214         new->next = 0;
215
216         data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
217         if (!data) {
218                 boot_params->hdr.setup_data = (unsigned long)new;
219         } else {
220                 while (data->next)
221                         data = (struct setup_data *)(unsigned long)data->next;
222                 data->next = (unsigned long)new;
223         }
224 }
225
226 efi_status_t efi_adjust_memory_range_protection(unsigned long start,
227                                                 unsigned long size)
228 {
229         efi_status_t status;
230         efi_gcd_memory_space_desc_t desc;
231         unsigned long end, next;
232         unsigned long rounded_start, rounded_end;
233         unsigned long unprotect_start, unprotect_size;
234
235         rounded_start = rounddown(start, EFI_PAGE_SIZE);
236         rounded_end = roundup(start + size, EFI_PAGE_SIZE);
237
238         if (memattr != NULL) {
239                 status = efi_call_proto(memattr, clear_memory_attributes,
240                                         rounded_start,
241                                         rounded_end - rounded_start,
242                                         EFI_MEMORY_XP);
243                 if (status != EFI_SUCCESS)
244                         efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
245                 return status;
246         }
247
248         if (efi_dxe_table == NULL)
249                 return EFI_SUCCESS;
250
251         /*
252          * Don't modify memory region attributes, they are
253          * already suitable, to lower the possibility to
254          * encounter firmware bugs.
255          */
256
257         for (end = start + size; start < end; start = next) {
258
259                 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
260
261                 if (status != EFI_SUCCESS)
262                         break;
263
264                 next = desc.base_address + desc.length;
265
266                 /*
267                  * Only system memory is suitable for trampoline/kernel image placement,
268                  * so only this type of memory needs its attributes to be modified.
269                  */
270
271                 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
272                     (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
273                         continue;
274
275                 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
276                 unprotect_size = min(rounded_end, next) - unprotect_start;
277
278                 status = efi_dxe_call(set_memory_space_attributes,
279                                       unprotect_start, unprotect_size,
280                                       EFI_MEMORY_WB);
281
282                 if (status != EFI_SUCCESS) {
283                         efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
284                                  unprotect_start,
285                                  unprotect_start + unprotect_size,
286                                  status);
287                         break;
288                 }
289         }
290         return EFI_SUCCESS;
291 }
292
293 static void setup_unaccepted_memory(void)
294 {
295         efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
296         sev_memory_acceptance_protocol_t *proto;
297         efi_status_t status;
298
299         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
300                 return;
301
302         /*
303          * Enable unaccepted memory before calling exit boot services in order
304          * for the UEFI to not accept all memory on EBS.
305          */
306         status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
307                              (void **)&proto);
308         if (status != EFI_SUCCESS)
309                 return;
310
311         status = efi_call_proto(proto, allow_unaccepted_memory);
312         if (status != EFI_SUCCESS)
313                 efi_err("Memory acceptance protocol failed\n");
314 }
315
316 static efi_char16_t *efistub_fw_vendor(void)
317 {
318         unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
319
320         return (efi_char16_t *)vendor;
321 }
322
323 static const efi_char16_t apple[] = L"Apple";
324
325 static void setup_quirks(struct boot_params *boot_params)
326 {
327         if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) &&
328             !memcmp(efistub_fw_vendor(), apple, sizeof(apple)))
329                 retrieve_apple_device_properties(boot_params);
330 }
331
332 /*
333  * See if we have Universal Graphics Adapter (UGA) protocol
334  */
335 static efi_status_t
336 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
337 {
338         efi_status_t status;
339         u32 width, height;
340         void **uga_handle = NULL;
341         efi_uga_draw_protocol_t *uga = NULL, *first_uga;
342         efi_handle_t handle;
343         int i;
344
345         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
346                              (void **)&uga_handle);
347         if (status != EFI_SUCCESS)
348                 return status;
349
350         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
351                              uga_proto, NULL, &size, uga_handle);
352         if (status != EFI_SUCCESS)
353                 goto free_handle;
354
355         height = 0;
356         width = 0;
357
358         first_uga = NULL;
359         for_each_efi_handle(handle, uga_handle, size, i) {
360                 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
361                 u32 w, h, depth, refresh;
362                 void *pciio;
363
364                 status = efi_bs_call(handle_protocol, handle, uga_proto,
365                                      (void **)&uga);
366                 if (status != EFI_SUCCESS)
367                         continue;
368
369                 pciio = NULL;
370                 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
371
372                 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
373                 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
374                         width = w;
375                         height = h;
376
377                         /*
378                          * Once we've found a UGA supporting PCIIO,
379                          * don't bother looking any further.
380                          */
381                         if (pciio)
382                                 break;
383
384                         first_uga = uga;
385                 }
386         }
387
388         if (!width && !height)
389                 goto free_handle;
390
391         /* EFI framebuffer */
392         si->orig_video_isVGA    = VIDEO_TYPE_EFI;
393
394         si->lfb_depth           = 32;
395         si->lfb_width           = width;
396         si->lfb_height          = height;
397
398         si->red_size            = 8;
399         si->red_pos             = 16;
400         si->green_size          = 8;
401         si->green_pos           = 8;
402         si->blue_size           = 8;
403         si->blue_pos            = 0;
404         si->rsvd_size           = 8;
405         si->rsvd_pos            = 24;
406
407 free_handle:
408         efi_bs_call(free_pool, uga_handle);
409
410         return status;
411 }
412
413 static void setup_graphics(struct boot_params *boot_params)
414 {
415         efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
416         struct screen_info *si;
417         efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
418         efi_status_t status;
419         unsigned long size;
420         void **gop_handle = NULL;
421         void **uga_handle = NULL;
422
423         si = &boot_params->screen_info;
424         memset(si, 0, sizeof(*si));
425
426         size = 0;
427         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
428                              &graphics_proto, NULL, &size, gop_handle);
429         if (status == EFI_BUFFER_TOO_SMALL)
430                 status = efi_setup_gop(si, &graphics_proto, size);
431
432         if (status != EFI_SUCCESS) {
433                 size = 0;
434                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
435                                      &uga_proto, NULL, &size, uga_handle);
436                 if (status == EFI_BUFFER_TOO_SMALL)
437                         setup_uga(si, &uga_proto, size);
438         }
439 }
440
441
442 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
443 {
444         efi_bs_call(exit, handle, status, 0, NULL);
445         for(;;)
446                 asm("hlt");
447 }
448
449 void __noreturn efi_stub_entry(efi_handle_t handle,
450                                efi_system_table_t *sys_table_arg,
451                                struct boot_params *boot_params);
452
453 /*
454  * Because the x86 boot code expects to be passed a boot_params we
455  * need to create one ourselves (usually the bootloader would create
456  * one for us).
457  */
458 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
459                                    efi_system_table_t *sys_table_arg)
460 {
461         static struct boot_params boot_params __page_aligned_bss;
462         struct setup_header *hdr = &boot_params.hdr;
463         efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
464         int options_size = 0;
465         efi_status_t status;
466         char *cmdline_ptr;
467
468         efi_system_table = sys_table_arg;
469
470         /* Check if we were booted by the EFI firmware */
471         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
472                 efi_exit(handle, EFI_INVALID_PARAMETER);
473
474         status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
475         if (status != EFI_SUCCESS) {
476                 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
477                 efi_exit(handle, status);
478         }
479
480         /* Assign the setup_header fields that the kernel actually cares about */
481         hdr->root_flags = 1;
482         hdr->vid_mode   = 0xffff;
483
484         hdr->type_of_loader = 0x21;
485
486         /* Convert unicode cmdline to ascii */
487         cmdline_ptr = efi_convert_cmdline(image, &options_size);
488         if (!cmdline_ptr)
489                 goto fail;
490
491         efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
492                           &boot_params.ext_cmd_line_ptr);
493
494         efi_stub_entry(handle, sys_table_arg, &boot_params);
495         /* not reached */
496
497 fail:
498         efi_exit(handle, status);
499 }
500
501 static void add_e820ext(struct boot_params *params,
502                         struct setup_data *e820ext, u32 nr_entries)
503 {
504         struct setup_data *data;
505
506         e820ext->type = SETUP_E820_EXT;
507         e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
508         e820ext->next = 0;
509
510         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
511
512         while (data && data->next)
513                 data = (struct setup_data *)(unsigned long)data->next;
514
515         if (data)
516                 data->next = (unsigned long)e820ext;
517         else
518                 params->hdr.setup_data = (unsigned long)e820ext;
519 }
520
521 static efi_status_t
522 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
523 {
524         struct boot_e820_entry *entry = params->e820_table;
525         struct efi_info *efi = &params->efi_info;
526         struct boot_e820_entry *prev = NULL;
527         u32 nr_entries;
528         u32 nr_desc;
529         int i;
530
531         nr_entries = 0;
532         nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
533
534         for (i = 0; i < nr_desc; i++) {
535                 efi_memory_desc_t *d;
536                 unsigned int e820_type = 0;
537                 unsigned long m = efi->efi_memmap;
538
539 #ifdef CONFIG_X86_64
540                 m |= (u64)efi->efi_memmap_hi << 32;
541 #endif
542
543                 d = efi_early_memdesc_ptr(m, efi->efi_memdesc_size, i);
544                 switch (d->type) {
545                 case EFI_RESERVED_TYPE:
546                 case EFI_RUNTIME_SERVICES_CODE:
547                 case EFI_RUNTIME_SERVICES_DATA:
548                 case EFI_MEMORY_MAPPED_IO:
549                 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
550                 case EFI_PAL_CODE:
551                         e820_type = E820_TYPE_RESERVED;
552                         break;
553
554                 case EFI_UNUSABLE_MEMORY:
555                         e820_type = E820_TYPE_UNUSABLE;
556                         break;
557
558                 case EFI_ACPI_RECLAIM_MEMORY:
559                         e820_type = E820_TYPE_ACPI;
560                         break;
561
562                 case EFI_LOADER_CODE:
563                 case EFI_LOADER_DATA:
564                 case EFI_BOOT_SERVICES_CODE:
565                 case EFI_BOOT_SERVICES_DATA:
566                 case EFI_CONVENTIONAL_MEMORY:
567                         if (efi_soft_reserve_enabled() &&
568                             (d->attribute & EFI_MEMORY_SP))
569                                 e820_type = E820_TYPE_SOFT_RESERVED;
570                         else
571                                 e820_type = E820_TYPE_RAM;
572                         break;
573
574                 case EFI_ACPI_MEMORY_NVS:
575                         e820_type = E820_TYPE_NVS;
576                         break;
577
578                 case EFI_PERSISTENT_MEMORY:
579                         e820_type = E820_TYPE_PMEM;
580                         break;
581
582                 case EFI_UNACCEPTED_MEMORY:
583                         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
584                                 continue;
585                         e820_type = E820_TYPE_RAM;
586                         process_unaccepted_memory(d->phys_addr,
587                                                   d->phys_addr + PAGE_SIZE * d->num_pages);
588                         break;
589                 default:
590                         continue;
591                 }
592
593                 /* Merge adjacent mappings */
594                 if (prev && prev->type == e820_type &&
595                     (prev->addr + prev->size) == d->phys_addr) {
596                         prev->size += d->num_pages << 12;
597                         continue;
598                 }
599
600                 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
601                         u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
602                                    sizeof(struct setup_data);
603
604                         if (!e820ext || e820ext_size < need)
605                                 return EFI_BUFFER_TOO_SMALL;
606
607                         /* boot_params map full, switch to e820 extended */
608                         entry = (struct boot_e820_entry *)e820ext->data;
609                 }
610
611                 entry->addr = d->phys_addr;
612                 entry->size = d->num_pages << PAGE_SHIFT;
613                 entry->type = e820_type;
614                 prev = entry++;
615                 nr_entries++;
616         }
617
618         if (nr_entries > ARRAY_SIZE(params->e820_table)) {
619                 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
620
621                 add_e820ext(params, e820ext, nr_e820ext);
622                 nr_entries -= nr_e820ext;
623         }
624
625         params->e820_entries = (u8)nr_entries;
626
627         return EFI_SUCCESS;
628 }
629
630 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
631                                   u32 *e820ext_size)
632 {
633         efi_status_t status;
634         unsigned long size;
635
636         size = sizeof(struct setup_data) +
637                 sizeof(struct e820_entry) * nr_desc;
638
639         if (*e820ext) {
640                 efi_bs_call(free_pool, *e820ext);
641                 *e820ext = NULL;
642                 *e820ext_size = 0;
643         }
644
645         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
646                              (void **)e820ext);
647         if (status == EFI_SUCCESS)
648                 *e820ext_size = size;
649
650         return status;
651 }
652
653 static efi_status_t allocate_e820(struct boot_params *params,
654                                   struct setup_data **e820ext,
655                                   u32 *e820ext_size)
656 {
657         struct efi_boot_memmap *map;
658         efi_status_t status;
659         __u32 nr_desc;
660
661         status = efi_get_memory_map(&map, false);
662         if (status != EFI_SUCCESS)
663                 return status;
664
665         nr_desc = map->map_size / map->desc_size;
666         if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
667                 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
668                                  EFI_MMAP_NR_SLACK_SLOTS;
669
670                 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
671         }
672
673         if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS)
674                 status = allocate_unaccepted_bitmap(nr_desc, map);
675
676         efi_bs_call(free_pool, map);
677         return status;
678 }
679
680 struct exit_boot_struct {
681         struct boot_params      *boot_params;
682         struct efi_info         *efi;
683 };
684
685 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
686                                    void *priv)
687 {
688         const char *signature;
689         struct exit_boot_struct *p = priv;
690
691         signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
692                                    : EFI32_LOADER_SIGNATURE;
693         memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
694
695         efi_set_u64_split((unsigned long)efi_system_table,
696                           &p->efi->efi_systab, &p->efi->efi_systab_hi);
697         p->efi->efi_memdesc_size        = map->desc_size;
698         p->efi->efi_memdesc_version     = map->desc_ver;
699         efi_set_u64_split((unsigned long)map->map,
700                           &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
701         p->efi->efi_memmap_size         = map->map_size;
702
703         return EFI_SUCCESS;
704 }
705
706 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
707 {
708         struct setup_data *e820ext = NULL;
709         __u32 e820ext_size = 0;
710         efi_status_t status;
711         struct exit_boot_struct priv;
712
713         priv.boot_params        = boot_params;
714         priv.efi                = &boot_params->efi_info;
715
716         status = allocate_e820(boot_params, &e820ext, &e820ext_size);
717         if (status != EFI_SUCCESS)
718                 return status;
719
720         /* Might as well exit boot services now */
721         status = efi_exit_boot_services(handle, &priv, exit_boot_func);
722         if (status != EFI_SUCCESS)
723                 return status;
724
725         /* Historic? */
726         boot_params->alt_mem_k  = 32 * 1024;
727
728         status = setup_e820(boot_params, e820ext, e820ext_size);
729         if (status != EFI_SUCCESS)
730                 return status;
731
732         return EFI_SUCCESS;
733 }
734
735 static bool have_unsupported_snp_features(void)
736 {
737         u64 unsupported;
738
739         unsupported = snp_get_unsupported_features(sev_get_status());
740         if (unsupported) {
741                 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
742                         unsupported);
743                 return true;
744         }
745         return false;
746 }
747
748 static void efi_get_seed(void *seed, int size)
749 {
750         efi_get_random_bytes(size, seed);
751
752         /*
753          * This only updates seed[0] when running on 32-bit, but in that case,
754          * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
755          */
756         *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
757 }
758
759 static void error(char *str)
760 {
761         efi_warn("Decompression failed: %s\n", str);
762 }
763
764 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
765 {
766         unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
767         unsigned long addr, alloc_size, entry;
768         efi_status_t status;
769         u32 seed[2] = {};
770
771         /* determine the required size of the allocation */
772         alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
773                            MIN_KERNEL_ALIGN);
774
775         if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
776                 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
777                 static const efi_char16_t ami[] = L"American Megatrends";
778
779                 efi_get_seed(seed, sizeof(seed));
780
781                 virt_addr += (range * seed[1]) >> 32;
782                 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
783
784                 /*
785                  * Older Dell systems with AMI UEFI firmware v2.0 may hang
786                  * while decompressing the kernel if physical address
787                  * randomization is enabled.
788                  *
789                  * https://bugzilla.kernel.org/show_bug.cgi?id=218173
790                  */
791                 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
792                     !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
793                         efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
794                         seed[0] = 0;
795                 }
796
797                 boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
798         }
799
800         status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
801                                   seed[0], EFI_LOADER_CODE,
802                                   EFI_X86_KERNEL_ALLOC_LIMIT);
803         if (status != EFI_SUCCESS)
804                 return status;
805
806         entry = decompress_kernel((void *)addr, virt_addr, error);
807         if (entry == ULONG_MAX) {
808                 efi_free(alloc_size, addr);
809                 return EFI_LOAD_ERROR;
810         }
811
812         *kernel_entry = addr + entry;
813
814         return efi_adjust_memory_range_protection(addr, kernel_total_size);
815 }
816
817 static void __noreturn enter_kernel(unsigned long kernel_addr,
818                                     struct boot_params *boot_params)
819 {
820         /* enter decompressed kernel with boot_params pointer in RSI/ESI */
821         asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
822
823         unreachable();
824 }
825
826 /*
827  * On success, this routine will jump to the relocated image directly and never
828  * return.  On failure, it will exit to the firmware via efi_exit() instead of
829  * returning.
830  */
831 void __noreturn efi_stub_entry(efi_handle_t handle,
832                                efi_system_table_t *sys_table_arg,
833                                struct boot_params *boot_params)
834 {
835         efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
836         struct setup_header *hdr = &boot_params->hdr;
837         const struct linux_efi_initrd *initrd = NULL;
838         unsigned long kernel_entry;
839         efi_status_t status;
840
841         boot_params_ptr = boot_params;
842
843         efi_system_table = sys_table_arg;
844         /* Check if we were booted by the EFI firmware */
845         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
846                 efi_exit(handle, EFI_INVALID_PARAMETER);
847
848         if (have_unsupported_snp_features())
849                 efi_exit(handle, EFI_UNSUPPORTED);
850
851         if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
852                 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
853                 if (efi_dxe_table &&
854                     efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
855                         efi_warn("Ignoring DXE services table: invalid signature\n");
856                         efi_dxe_table = NULL;
857                 }
858         }
859
860         /* grab the memory attributes protocol if it exists */
861         efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
862
863         status = efi_setup_5level_paging();
864         if (status != EFI_SUCCESS) {
865                 efi_err("efi_setup_5level_paging() failed!\n");
866                 goto fail;
867         }
868
869 #ifdef CONFIG_CMDLINE_BOOL
870         status = efi_parse_options(CONFIG_CMDLINE);
871         if (status != EFI_SUCCESS) {
872                 efi_err("Failed to parse options\n");
873                 goto fail;
874         }
875 #endif
876         if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
877                 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
878                                                ((u64)boot_params->ext_cmd_line_ptr << 32));
879                 status = efi_parse_options((char *)cmdline_paddr);
880                 if (status != EFI_SUCCESS) {
881                         efi_err("Failed to parse options\n");
882                         goto fail;
883                 }
884         }
885
886         status = efi_decompress_kernel(&kernel_entry);
887         if (status != EFI_SUCCESS) {
888                 efi_err("Failed to decompress kernel\n");
889                 goto fail;
890         }
891
892         /*
893          * At this point, an initrd may already have been loaded by the
894          * bootloader and passed via bootparams. We permit an initrd loaded
895          * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
896          *
897          * If the device path is not present, any command-line initrd=
898          * arguments will be processed only if image is not NULL, which will be
899          * the case only if we were loaded via the PE entry point.
900          */
901         status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
902                                  &initrd);
903         if (status != EFI_SUCCESS)
904                 goto fail;
905         if (initrd && initrd->size > 0) {
906                 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
907                                   &boot_params->ext_ramdisk_image);
908                 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
909                                   &boot_params->ext_ramdisk_size);
910         }
911
912
913         /*
914          * If the boot loader gave us a value for secure_boot then we use that,
915          * otherwise we ask the BIOS.
916          */
917         if (boot_params->secure_boot == efi_secureboot_mode_unset)
918                 boot_params->secure_boot = efi_get_secureboot();
919
920         /* Ask the firmware to clear memory on unclean shutdown */
921         efi_enable_reset_attack_mitigation();
922
923         efi_random_get_seed();
924
925         efi_retrieve_tpm2_eventlog();
926
927         setup_graphics(boot_params);
928
929         setup_efi_pci(boot_params);
930
931         setup_quirks(boot_params);
932
933         setup_unaccepted_memory();
934
935         status = exit_boot(boot_params, handle);
936         if (status != EFI_SUCCESS) {
937                 efi_err("exit_boot() failed!\n");
938                 goto fail;
939         }
940
941         /*
942          * Call the SEV init code while still running with the firmware's
943          * GDT/IDT, so #VC exceptions will be handled by EFI.
944          */
945         sev_enable(boot_params);
946
947         efi_5level_switch();
948
949         enter_kernel(kernel_entry, boot_params);
950 fail:
951         efi_err("efi_stub_entry() failed!\n");
952
953         efi_exit(handle, status);
954 }
955
956 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
957 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
958                         struct boot_params *boot_params)
959 {
960         extern char _bss[], _ebss[];
961
962         memset(_bss, 0, _ebss - _bss);
963         efi_stub_entry(handle, sys_table_arg, boot_params);
964 }
965
966 #ifndef CONFIG_EFI_MIXED
967 extern __alias(efi_handover_entry)
968 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
969                       struct boot_params *boot_params);
970
971 extern __alias(efi_handover_entry)
972 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
973                       struct boot_params *boot_params);
974 #endif
975 #endif