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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Helper functions used by the EFI stub on multiple
4 * architectures. This should be #included by the EFI stub
5 * implementation files.
6 *
7 * Copyright 2011 Intel Corporation; author Matt Fleming
8 */
9
10#include <linux/stdarg.h>
11
12#include <linux/efi.h>
13#include <linux/kernel.h>
14#include <linux/overflow.h>
15#include <asm/efi.h>
16#include <asm/setup.h>
17
18#include "efistub.h"
19
20bool efi_nochunk;
21bool efi_nokaslr = !IS_ENABLED(CONFIG_RANDOMIZE_BASE);
22bool efi_novamap;
23
24static bool efi_noinitrd;
25static bool efi_nosoftreserve;
26static bool efi_disable_pci_dma = IS_ENABLED(CONFIG_EFI_DISABLE_PCI_DMA);
27
28int efi_mem_encrypt;
29
30bool __pure __efi_soft_reserve_enabled(void)
31{
32 return !efi_nosoftreserve;
33}
34
35/**
36 * efi_parse_options() - Parse EFI command line options
37 * @cmdline: kernel command line
38 *
39 * Parse the ASCII string @cmdline for EFI options, denoted by the efi=
40 * option, e.g. efi=nochunk.
41 *
42 * It should be noted that efi= is parsed in two very different
43 * environments, first in the early boot environment of the EFI boot
44 * stub, and subsequently during the kernel boot.
45 *
46 * Return: status code
47 */
48efi_status_t efi_parse_options(char const *cmdline)
49{
50 size_t len;
51 efi_status_t status;
52 char *str, *buf;
53
54 if (!cmdline)
55 return EFI_SUCCESS;
56
57 len = strnlen(cmdline, COMMAND_LINE_SIZE - 1) + 1;
58 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, len, (void **)&buf);
59 if (status != EFI_SUCCESS)
60 return status;
61
62 memcpy(buf, cmdline, len - 1);
63 buf[len - 1] = '\0';
64 str = skip_spaces(buf);
65
66 while (*str) {
67 char *param, *val;
68
69 str = next_arg(str, ¶m, &val);
70 if (!val && !strcmp(param, "--"))
71 break;
72
73 if (!strcmp(param, "nokaslr")) {
74 efi_nokaslr = true;
75 } else if (!strcmp(param, "quiet")) {
76 efi_loglevel = CONSOLE_LOGLEVEL_QUIET;
77 } else if (!strcmp(param, "noinitrd")) {
78 efi_noinitrd = true;
79 } else if (IS_ENABLED(CONFIG_X86_64) && !strcmp(param, "no5lvl")) {
80 efi_no5lvl = true;
81 } else if (IS_ENABLED(CONFIG_ARCH_HAS_MEM_ENCRYPT) &&
82 !strcmp(param, "mem_encrypt") && val) {
83 if (parse_option_str(val, "on"))
84 efi_mem_encrypt = 1;
85 else if (parse_option_str(val, "off"))
86 efi_mem_encrypt = -1;
87 } else if (!strcmp(param, "efi") && val) {
88 efi_nochunk = parse_option_str(val, "nochunk");
89 efi_novamap |= parse_option_str(val, "novamap");
90
91 efi_nosoftreserve = IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) &&
92 parse_option_str(val, "nosoftreserve");
93
94 if (parse_option_str(val, "disable_early_pci_dma"))
95 efi_disable_pci_dma = true;
96 if (parse_option_str(val, "no_disable_early_pci_dma"))
97 efi_disable_pci_dma = false;
98 if (parse_option_str(val, "debug"))
99 efi_loglevel = CONSOLE_LOGLEVEL_DEBUG;
100 } else if (!strcmp(param, "video") &&
101 val && strstarts(val, "efifb:")) {
102 efi_parse_option_graphics(val + strlen("efifb:"));
103 }
104 }
105 efi_bs_call(free_pool, buf);
106 return EFI_SUCCESS;
107}
108
109/*
110 * The EFI_LOAD_OPTION descriptor has the following layout:
111 * u32 Attributes;
112 * u16 FilePathListLength;
113 * u16 Description[];
114 * efi_device_path_protocol_t FilePathList[];
115 * u8 OptionalData[];
116 *
117 * This function validates and unpacks the variable-size data fields.
118 */
119static
120bool efi_load_option_unpack(efi_load_option_unpacked_t *dest,
121 const efi_load_option_t *src, size_t size)
122{
123 const void *pos;
124 u16 c;
125 efi_device_path_protocol_t header;
126 const efi_char16_t *description;
127 const efi_device_path_protocol_t *file_path_list;
128
129 if (size < offsetof(efi_load_option_t, variable_data))
130 return false;
131 pos = src->variable_data;
132 size -= offsetof(efi_load_option_t, variable_data);
133
134 if ((src->attributes & ~EFI_LOAD_OPTION_MASK) != 0)
135 return false;
136
137 /* Scan description. */
138 description = pos;
139 do {
140 if (size < sizeof(c))
141 return false;
142 c = *(const u16 *)pos;
143 pos += sizeof(c);
144 size -= sizeof(c);
145 } while (c != L'\0');
146
147 /* Scan file_path_list. */
148 file_path_list = pos;
149 do {
150 if (size < sizeof(header))
151 return false;
152 header = *(const efi_device_path_protocol_t *)pos;
153 if (header.length < sizeof(header))
154 return false;
155 if (size < header.length)
156 return false;
157 pos += header.length;
158 size -= header.length;
159 } while ((header.type != EFI_DEV_END_PATH && header.type != EFI_DEV_END_PATH2) ||
160 (header.sub_type != EFI_DEV_END_ENTIRE));
161 if (pos != (const void *)file_path_list + src->file_path_list_length)
162 return false;
163
164 dest->attributes = src->attributes;
165 dest->file_path_list_length = src->file_path_list_length;
166 dest->description = description;
167 dest->file_path_list = file_path_list;
168 dest->optional_data_size = size;
169 dest->optional_data = size ? pos : NULL;
170
171 return true;
172}
173
174/*
175 * At least some versions of Dell firmware pass the entire contents of the
176 * Boot#### variable, i.e. the EFI_LOAD_OPTION descriptor, rather than just the
177 * OptionalData field.
178 *
179 * Detect this case and extract OptionalData.
180 */
181void efi_apply_loadoptions_quirk(const void **load_options, u32 *load_options_size)
182{
183 const efi_load_option_t *load_option = *load_options;
184 efi_load_option_unpacked_t load_option_unpacked;
185
186 if (!IS_ENABLED(CONFIG_X86))
187 return;
188 if (!load_option)
189 return;
190 if (*load_options_size < sizeof(*load_option))
191 return;
192 if ((load_option->attributes & ~EFI_LOAD_OPTION_BOOT_MASK) != 0)
193 return;
194
195 if (!efi_load_option_unpack(&load_option_unpacked, load_option, *load_options_size))
196 return;
197
198 efi_warn_once(FW_BUG "LoadOptions is an EFI_LOAD_OPTION descriptor\n");
199 efi_warn_once(FW_BUG "Using OptionalData as a workaround\n");
200
201 *load_options = load_option_unpacked.optional_data;
202 *load_options_size = load_option_unpacked.optional_data_size;
203}
204
205enum efistub_event_type {
206 EFISTUB_EVT_INITRD,
207 EFISTUB_EVT_LOAD_OPTIONS,
208 EFISTUB_EVT_COUNT,
209};
210
211#define STR_WITH_SIZE(s) sizeof(s), s
212
213static const struct {
214 u32 pcr_index;
215 u32 event_id;
216 u32 event_data_len;
217 u8 event_data[52];
218} events[] = {
219 [EFISTUB_EVT_INITRD] = {
220 9,
221 INITRD_EVENT_TAG_ID,
222 STR_WITH_SIZE("Linux initrd")
223 },
224 [EFISTUB_EVT_LOAD_OPTIONS] = {
225 9,
226 LOAD_OPTIONS_EVENT_TAG_ID,
227 STR_WITH_SIZE("LOADED_IMAGE::LoadOptions")
228 },
229};
230
231static_assert(sizeof(efi_tcg2_event_t) == sizeof(efi_cc_event_t));
232
233union efistub_event {
234 efi_tcg2_event_t tcg2_data;
235 efi_cc_event_t cc_data;
236};
237
238struct efistub_measured_event {
239 union efistub_event event_data;
240 TCG_PCClientTaggedEvent tagged_event __packed;
241};
242
243static efi_status_t efi_measure_tagged_event(unsigned long load_addr,
244 unsigned long load_size,
245 enum efistub_event_type event)
246{
247 union {
248 efi_status_t
249 (__efiapi *hash_log_extend_event)(void *, u64, efi_physical_addr_t,
250 u64, const union efistub_event *);
251 struct { u32 hash_log_extend_event; } mixed_mode;
252 } method;
253 struct efistub_measured_event *evt;
254 int size = struct_size(evt, tagged_event.tagged_event_data,
255 events[event].event_data_len);
256 efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID;
257 efi_tcg2_protocol_t *tcg2 = NULL;
258 union efistub_event ev;
259 efi_status_t status;
260 void *protocol;
261
262 efi_bs_call(locate_protocol, &tcg2_guid, NULL, (void **)&tcg2);
263 if (tcg2) {
264 ev.tcg2_data = (struct efi_tcg2_event){
265 .event_size = size,
266 .event_header.header_size = sizeof(ev.tcg2_data.event_header),
267 .event_header.header_version = EFI_TCG2_EVENT_HEADER_VERSION,
268 .event_header.pcr_index = events[event].pcr_index,
269 .event_header.event_type = EV_EVENT_TAG,
270 };
271 protocol = tcg2;
272 method.hash_log_extend_event =
273 (void *)efi_table_attr(tcg2, hash_log_extend_event);
274 } else {
275 efi_guid_t cc_guid = EFI_CC_MEASUREMENT_PROTOCOL_GUID;
276 efi_cc_protocol_t *cc = NULL;
277
278 efi_bs_call(locate_protocol, &cc_guid, NULL, (void **)&cc);
279 if (!cc)
280 return EFI_UNSUPPORTED;
281
282 ev.cc_data = (struct efi_cc_event){
283 .event_size = size,
284 .event_header.header_size = sizeof(ev.cc_data.event_header),
285 .event_header.header_version = EFI_CC_EVENT_HEADER_VERSION,
286 .event_header.event_type = EV_EVENT_TAG,
287 };
288
289 status = efi_call_proto(cc, map_pcr_to_mr_index,
290 events[event].pcr_index,
291 &ev.cc_data.event_header.mr_index);
292 if (status != EFI_SUCCESS)
293 goto fail;
294
295 protocol = cc;
296 method.hash_log_extend_event =
297 (void *)efi_table_attr(cc, hash_log_extend_event);
298 }
299
300 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size, (void **)&evt);
301 if (status != EFI_SUCCESS)
302 goto fail;
303
304 *evt = (struct efistub_measured_event) {
305 .event_data = ev,
306 .tagged_event.tagged_event_id = events[event].event_id,
307 .tagged_event.tagged_event_data_size = events[event].event_data_len,
308 };
309
310 memcpy(evt->tagged_event.tagged_event_data, events[event].event_data,
311 events[event].event_data_len);
312
313 status = efi_fn_call(&method, hash_log_extend_event, protocol, 0,
314 load_addr, load_size, &evt->event_data);
315 efi_bs_call(free_pool, evt);
316
317 if (status == EFI_SUCCESS)
318 return EFI_SUCCESS;
319
320fail:
321 efi_warn("Failed to measure data for event %d: 0x%lx\n", event, status);
322 return status;
323}
324
325/*
326 * Convert the unicode UEFI command line to ASCII to pass to kernel.
327 * Size of memory allocated return in *cmd_line_len.
328 * Returns NULL on error.
329 */
330char *efi_convert_cmdline(efi_loaded_image_t *image, int *cmd_line_len)
331{
332 const efi_char16_t *options = efi_table_attr(image, load_options);
333 u32 options_size = efi_table_attr(image, load_options_size);
334 int options_bytes = 0, safe_options_bytes = 0; /* UTF-8 bytes */
335 unsigned long cmdline_addr = 0;
336 const efi_char16_t *s2;
337 bool in_quote = false;
338 efi_status_t status;
339 u32 options_chars;
340
341 if (options_size > 0)
342 efi_measure_tagged_event((unsigned long)options, options_size,
343 EFISTUB_EVT_LOAD_OPTIONS);
344
345 efi_apply_loadoptions_quirk((const void **)&options, &options_size);
346 options_chars = options_size / sizeof(efi_char16_t);
347
348 if (options) {
349 s2 = options;
350 while (options_bytes < COMMAND_LINE_SIZE && options_chars--) {
351 efi_char16_t c = *s2++;
352
353 if (c < 0x80) {
354 if (c == L'\0' || c == L'\n')
355 break;
356 if (c == L'"')
357 in_quote = !in_quote;
358 else if (!in_quote && isspace((char)c))
359 safe_options_bytes = options_bytes;
360
361 options_bytes++;
362 continue;
363 }
364
365 /*
366 * Get the number of UTF-8 bytes corresponding to a
367 * UTF-16 character.
368 * The first part handles everything in the BMP.
369 */
370 options_bytes += 2 + (c >= 0x800);
371 /*
372 * Add one more byte for valid surrogate pairs. Invalid
373 * surrogates will be replaced with 0xfffd and take up
374 * only 3 bytes.
375 */
376 if ((c & 0xfc00) == 0xd800) {
377 /*
378 * If the very last word is a high surrogate,
379 * we must ignore it since we can't access the
380 * low surrogate.
381 */
382 if (!options_chars) {
383 options_bytes -= 3;
384 } else if ((*s2 & 0xfc00) == 0xdc00) {
385 options_bytes++;
386 options_chars--;
387 s2++;
388 }
389 }
390 }
391 if (options_bytes >= COMMAND_LINE_SIZE) {
392 options_bytes = safe_options_bytes;
393 efi_err("Command line is too long: truncated to %d bytes\n",
394 options_bytes);
395 }
396 }
397
398 options_bytes++; /* NUL termination */
399
400 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, options_bytes,
401 (void **)&cmdline_addr);
402 if (status != EFI_SUCCESS)
403 return NULL;
404
405 snprintf((char *)cmdline_addr, options_bytes, "%.*ls",
406 options_bytes - 1, options);
407
408 *cmd_line_len = options_bytes;
409 return (char *)cmdline_addr;
410}
411
412/**
413 * efi_exit_boot_services() - Exit boot services
414 * @handle: handle of the exiting image
415 * @priv: argument to be passed to @priv_func
416 * @priv_func: function to process the memory map before exiting boot services
417 *
418 * Handle calling ExitBootServices according to the requirements set out by the
419 * spec. Obtains the current memory map, and returns that info after calling
420 * ExitBootServices. The client must specify a function to perform any
421 * processing of the memory map data prior to ExitBootServices. A client
422 * specific structure may be passed to the function via priv. The client
423 * function may be called multiple times.
424 *
425 * Return: status code
426 */
427efi_status_t efi_exit_boot_services(void *handle, void *priv,
428 efi_exit_boot_map_processing priv_func)
429{
430 struct efi_boot_memmap *map;
431 efi_status_t status;
432
433 if (efi_disable_pci_dma)
434 efi_pci_disable_bridge_busmaster();
435
436 status = efi_get_memory_map(&map, true);
437 if (status != EFI_SUCCESS)
438 return status;
439
440 status = priv_func(map, priv);
441 if (status != EFI_SUCCESS) {
442 efi_bs_call(free_pool, map);
443 return status;
444 }
445
446 status = efi_bs_call(exit_boot_services, handle, map->map_key);
447
448 if (status == EFI_INVALID_PARAMETER) {
449 /*
450 * The memory map changed between efi_get_memory_map() and
451 * exit_boot_services(). Per the UEFI Spec v2.6, Section 6.4:
452 * EFI_BOOT_SERVICES.ExitBootServices we need to get the
453 * updated map, and try again. The spec implies one retry
454 * should be sufficent, which is confirmed against the EDK2
455 * implementation. Per the spec, we can only invoke
456 * get_memory_map() and exit_boot_services() - we cannot alloc
457 * so efi_get_memory_map() cannot be used, and we must reuse
458 * the buffer. For all practical purposes, the headroom in the
459 * buffer should account for any changes in the map so the call
460 * to get_memory_map() is expected to succeed here.
461 */
462 map->map_size = map->buff_size;
463 status = efi_bs_call(get_memory_map,
464 &map->map_size,
465 &map->map,
466 &map->map_key,
467 &map->desc_size,
468 &map->desc_ver);
469
470 /* exit_boot_services() was called, thus cannot free */
471 if (status != EFI_SUCCESS)
472 return status;
473
474 status = priv_func(map, priv);
475 /* exit_boot_services() was called, thus cannot free */
476 if (status != EFI_SUCCESS)
477 return status;
478
479 status = efi_bs_call(exit_boot_services, handle, map->map_key);
480 }
481
482 return status;
483}
484
485/**
486 * get_efi_config_table() - retrieve UEFI configuration table
487 * @guid: GUID of the configuration table to be retrieved
488 * Return: pointer to the configuration table or NULL
489 */
490void *get_efi_config_table(efi_guid_t guid)
491{
492 unsigned long tables = efi_table_attr(efi_system_table, tables);
493 int nr_tables = efi_table_attr(efi_system_table, nr_tables);
494 int i;
495
496 for (i = 0; i < nr_tables; i++) {
497 efi_config_table_t *t = (void *)tables;
498
499 if (efi_guidcmp(t->guid, guid) == 0)
500 return efi_table_attr(t, table);
501
502 tables += efi_is_native() ? sizeof(efi_config_table_t)
503 : sizeof(efi_config_table_32_t);
504 }
505 return NULL;
506}
507
508/*
509 * The LINUX_EFI_INITRD_MEDIA_GUID vendor media device path below provides a way
510 * for the firmware or bootloader to expose the initrd data directly to the stub
511 * via the trivial LoadFile2 protocol, which is defined in the UEFI spec, and is
512 * very easy to implement. It is a simple Linux initrd specific conduit between
513 * kernel and firmware, allowing us to put the EFI stub (being part of the
514 * kernel) in charge of where and when to load the initrd, while leaving it up
515 * to the firmware to decide whether it needs to expose its filesystem hierarchy
516 * via EFI protocols.
517 */
518static const struct {
519 struct efi_vendor_dev_path vendor;
520 struct efi_generic_dev_path end;
521} __packed initrd_dev_path = {
522 {
523 {
524 EFI_DEV_MEDIA,
525 EFI_DEV_MEDIA_VENDOR,
526 sizeof(struct efi_vendor_dev_path),
527 },
528 LINUX_EFI_INITRD_MEDIA_GUID
529 }, {
530 EFI_DEV_END_PATH,
531 EFI_DEV_END_ENTIRE,
532 sizeof(struct efi_generic_dev_path)
533 }
534};
535
536/**
537 * efi_load_initrd_dev_path() - load the initrd from the Linux initrd device path
538 * @initrd: pointer of struct to store the address where the initrd was loaded
539 * and the size of the loaded initrd
540 * @max: upper limit for the initrd memory allocation
541 *
542 * Return:
543 * * %EFI_SUCCESS if the initrd was loaded successfully, in which
544 * case @load_addr and @load_size are assigned accordingly
545 * * %EFI_NOT_FOUND if no LoadFile2 protocol exists on the initrd device path
546 * * %EFI_OUT_OF_RESOURCES if memory allocation failed
547 * * %EFI_LOAD_ERROR in all other cases
548 */
549static
550efi_status_t efi_load_initrd_dev_path(struct linux_efi_initrd *initrd,
551 unsigned long max)
552{
553 efi_guid_t lf2_proto_guid = EFI_LOAD_FILE2_PROTOCOL_GUID;
554 efi_device_path_protocol_t *dp;
555 efi_load_file2_protocol_t *lf2;
556 efi_handle_t handle;
557 efi_status_t status;
558
559 dp = (efi_device_path_protocol_t *)&initrd_dev_path;
560 status = efi_bs_call(locate_device_path, &lf2_proto_guid, &dp, &handle);
561 if (status != EFI_SUCCESS)
562 return status;
563
564 status = efi_bs_call(handle_protocol, handle, &lf2_proto_guid,
565 (void **)&lf2);
566 if (status != EFI_SUCCESS)
567 return status;
568
569 initrd->size = 0;
570 status = efi_call_proto(lf2, load_file, dp, false, &initrd->size, NULL);
571 if (status != EFI_BUFFER_TOO_SMALL)
572 return EFI_LOAD_ERROR;
573
574 status = efi_allocate_pages(initrd->size, &initrd->base, max);
575 if (status != EFI_SUCCESS)
576 return status;
577
578 status = efi_call_proto(lf2, load_file, dp, false, &initrd->size,
579 (void *)initrd->base);
580 if (status != EFI_SUCCESS) {
581 efi_free(initrd->size, initrd->base);
582 return EFI_LOAD_ERROR;
583 }
584 return EFI_SUCCESS;
585}
586
587static
588efi_status_t efi_load_initrd_cmdline(efi_loaded_image_t *image,
589 struct linux_efi_initrd *initrd,
590 unsigned long soft_limit,
591 unsigned long hard_limit)
592{
593 if (image == NULL)
594 return EFI_UNSUPPORTED;
595
596 return handle_cmdline_files(image, L"initrd=", sizeof(L"initrd=") - 2,
597 soft_limit, hard_limit,
598 &initrd->base, &initrd->size);
599}
600
601/**
602 * efi_load_initrd() - Load initial RAM disk
603 * @image: EFI loaded image protocol
604 * @soft_limit: preferred address for loading the initrd
605 * @hard_limit: upper limit address for loading the initrd
606 *
607 * Return: status code
608 */
609efi_status_t efi_load_initrd(efi_loaded_image_t *image,
610 unsigned long soft_limit,
611 unsigned long hard_limit,
612 const struct linux_efi_initrd **out)
613{
614 efi_guid_t tbl_guid = LINUX_EFI_INITRD_MEDIA_GUID;
615 efi_status_t status = EFI_SUCCESS;
616 struct linux_efi_initrd initrd, *tbl;
617
618 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD) || efi_noinitrd)
619 return EFI_SUCCESS;
620
621 status = efi_load_initrd_dev_path(&initrd, hard_limit);
622 if (status == EFI_SUCCESS) {
623 efi_info("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
624 if (initrd.size > 0 &&
625 efi_measure_tagged_event(initrd.base, initrd.size,
626 EFISTUB_EVT_INITRD) == EFI_SUCCESS)
627 efi_info("Measured initrd data into PCR 9\n");
628 } else if (status == EFI_NOT_FOUND) {
629 status = efi_load_initrd_cmdline(image, &initrd, soft_limit,
630 hard_limit);
631 /* command line loader disabled or no initrd= passed? */
632 if (status == EFI_UNSUPPORTED || status == EFI_NOT_READY)
633 return EFI_SUCCESS;
634 if (status == EFI_SUCCESS)
635 efi_info("Loaded initrd from command line option\n");
636 }
637 if (status != EFI_SUCCESS)
638 goto failed;
639
640 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(initrd),
641 (void **)&tbl);
642 if (status != EFI_SUCCESS)
643 goto free_initrd;
644
645 *tbl = initrd;
646 status = efi_bs_call(install_configuration_table, &tbl_guid, tbl);
647 if (status != EFI_SUCCESS)
648 goto free_tbl;
649
650 if (out)
651 *out = tbl;
652 return EFI_SUCCESS;
653
654free_tbl:
655 efi_bs_call(free_pool, tbl);
656free_initrd:
657 efi_free(initrd.size, initrd.base);
658failed:
659 efi_err("Failed to load initrd: 0x%lx\n", status);
660 return status;
661}
662
663/**
664 * efi_wait_for_key() - Wait for key stroke
665 * @usec: number of microseconds to wait for key stroke
666 * @key: key entered
667 *
668 * Wait for up to @usec microseconds for a key stroke.
669 *
670 * Return: status code, EFI_SUCCESS if key received
671 */
672efi_status_t efi_wait_for_key(unsigned long usec, efi_input_key_t *key)
673{
674 efi_event_t events[2], timer;
675 unsigned long index;
676 efi_simple_text_input_protocol_t *con_in;
677 efi_status_t status;
678
679 con_in = efi_table_attr(efi_system_table, con_in);
680 if (!con_in)
681 return EFI_UNSUPPORTED;
682 efi_set_event_at(events, 0, efi_table_attr(con_in, wait_for_key));
683
684 status = efi_bs_call(create_event, EFI_EVT_TIMER, 0, NULL, NULL, &timer);
685 if (status != EFI_SUCCESS)
686 return status;
687
688 status = efi_bs_call(set_timer, timer, EfiTimerRelative,
689 EFI_100NSEC_PER_USEC * usec);
690 if (status != EFI_SUCCESS)
691 return status;
692 efi_set_event_at(events, 1, timer);
693
694 status = efi_bs_call(wait_for_event, 2, events, &index);
695 if (status == EFI_SUCCESS) {
696 if (index == 0)
697 status = efi_call_proto(con_in, read_keystroke, key);
698 else
699 status = EFI_TIMEOUT;
700 }
701
702 efi_bs_call(close_event, timer);
703
704 return status;
705}
706
707/**
708 * efi_remap_image - Remap a loaded image with the appropriate permissions
709 * for code and data
710 *
711 * @image_base: the base of the image in memory
712 * @alloc_size: the size of the area in memory occupied by the image
713 * @code_size: the size of the leading part of the image containing code
714 * and read-only data
715 *
716 * efi_remap_image() uses the EFI memory attribute protocol to remap the code
717 * region of the loaded image read-only/executable, and the remainder
718 * read-write/non-executable. The code region is assumed to start at the base
719 * of the image, and will therefore cover the PE/COFF header as well.
720 */
721void efi_remap_image(unsigned long image_base, unsigned alloc_size,
722 unsigned long code_size)
723{
724 efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
725 efi_memory_attribute_protocol_t *memattr;
726 efi_status_t status;
727 u64 attr;
728
729 /*
730 * If the firmware implements the EFI_MEMORY_ATTRIBUTE_PROTOCOL, let's
731 * invoke it to remap the text/rodata region of the decompressed image
732 * as read-only and the data/bss region as non-executable.
733 */
734 status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
735 if (status != EFI_SUCCESS)
736 return;
737
738 // Get the current attributes for the entire region
739 status = memattr->get_memory_attributes(memattr, image_base,
740 alloc_size, &attr);
741 if (status != EFI_SUCCESS) {
742 efi_warn("Failed to retrieve memory attributes for image region: 0x%lx\n",
743 status);
744 return;
745 }
746
747 // Mark the code region as read-only
748 status = memattr->set_memory_attributes(memattr, image_base, code_size,
749 EFI_MEMORY_RO);
750 if (status != EFI_SUCCESS) {
751 efi_warn("Failed to remap code region read-only\n");
752 return;
753 }
754
755 // If the entire region was already mapped as non-exec, clear the
756 // attribute from the code region. Otherwise, set it on the data
757 // region.
758 if (attr & EFI_MEMORY_XP) {
759 status = memattr->clear_memory_attributes(memattr, image_base,
760 code_size,
761 EFI_MEMORY_XP);
762 if (status != EFI_SUCCESS)
763 efi_warn("Failed to remap code region executable\n");
764 } else {
765 status = memattr->set_memory_attributes(memattr,
766 image_base + code_size,
767 alloc_size - code_size,
768 EFI_MEMORY_XP);
769 if (status != EFI_SUCCESS)
770 efi_warn("Failed to remap data region non-executable\n");
771 }
772}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Helper functions used by the EFI stub on multiple
4 * architectures. This should be #included by the EFI stub
5 * implementation files.
6 *
7 * Copyright 2011 Intel Corporation; author Matt Fleming
8 */
9
10#include <linux/efi.h>
11#include <asm/efi.h>
12
13#include "efistub.h"
14
15/*
16 * Some firmware implementations have problems reading files in one go.
17 * A read chunk size of 1MB seems to work for most platforms.
18 *
19 * Unfortunately, reading files in chunks triggers *other* bugs on some
20 * platforms, so we provide a way to disable this workaround, which can
21 * be done by passing "efi=nochunk" on the EFI boot stub command line.
22 *
23 * If you experience issues with initrd images being corrupt it's worth
24 * trying efi=nochunk, but chunking is enabled by default because there
25 * are far more machines that require the workaround than those that
26 * break with it enabled.
27 */
28#define EFI_READ_CHUNK_SIZE (1024 * 1024)
29
30static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE;
31
32static int __section(.data) __nokaslr;
33static int __section(.data) __quiet;
34static int __section(.data) __novamap;
35
36int __pure nokaslr(void)
37{
38 return __nokaslr;
39}
40int __pure is_quiet(void)
41{
42 return __quiet;
43}
44int __pure novamap(void)
45{
46 return __novamap;
47}
48
49#define EFI_MMAP_NR_SLACK_SLOTS 8
50
51struct file_info {
52 efi_file_handle_t *handle;
53 u64 size;
54};
55
56void efi_printk(efi_system_table_t *sys_table_arg, char *str)
57{
58 char *s8;
59
60 for (s8 = str; *s8; s8++) {
61 efi_char16_t ch[2] = { 0 };
62
63 ch[0] = *s8;
64 if (*s8 == '\n') {
65 efi_char16_t nl[2] = { '\r', 0 };
66 efi_char16_printk(sys_table_arg, nl);
67 }
68
69 efi_char16_printk(sys_table_arg, ch);
70 }
71}
72
73static inline bool mmap_has_headroom(unsigned long buff_size,
74 unsigned long map_size,
75 unsigned long desc_size)
76{
77 unsigned long slack = buff_size - map_size;
78
79 return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;
80}
81
82efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
83 struct efi_boot_memmap *map)
84{
85 efi_memory_desc_t *m = NULL;
86 efi_status_t status;
87 unsigned long key;
88 u32 desc_version;
89
90 *map->desc_size = sizeof(*m);
91 *map->map_size = *map->desc_size * 32;
92 *map->buff_size = *map->map_size;
93again:
94 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
95 *map->map_size, (void **)&m);
96 if (status != EFI_SUCCESS)
97 goto fail;
98
99 *map->desc_size = 0;
100 key = 0;
101 status = efi_call_early(get_memory_map, map->map_size, m,
102 &key, map->desc_size, &desc_version);
103 if (status == EFI_BUFFER_TOO_SMALL ||
104 !mmap_has_headroom(*map->buff_size, *map->map_size,
105 *map->desc_size)) {
106 efi_call_early(free_pool, m);
107 /*
108 * Make sure there is some entries of headroom so that the
109 * buffer can be reused for a new map after allocations are
110 * no longer permitted. Its unlikely that the map will grow to
111 * exceed this headroom once we are ready to trigger
112 * ExitBootServices()
113 */
114 *map->map_size += *map->desc_size * EFI_MMAP_NR_SLACK_SLOTS;
115 *map->buff_size = *map->map_size;
116 goto again;
117 }
118
119 if (status != EFI_SUCCESS)
120 efi_call_early(free_pool, m);
121
122 if (map->key_ptr && status == EFI_SUCCESS)
123 *map->key_ptr = key;
124 if (map->desc_ver && status == EFI_SUCCESS)
125 *map->desc_ver = desc_version;
126
127fail:
128 *map->map = m;
129 return status;
130}
131
132
133unsigned long get_dram_base(efi_system_table_t *sys_table_arg)
134{
135 efi_status_t status;
136 unsigned long map_size, buff_size;
137 unsigned long membase = EFI_ERROR;
138 struct efi_memory_map map;
139 efi_memory_desc_t *md;
140 struct efi_boot_memmap boot_map;
141
142 boot_map.map = (efi_memory_desc_t **)&map.map;
143 boot_map.map_size = &map_size;
144 boot_map.desc_size = &map.desc_size;
145 boot_map.desc_ver = NULL;
146 boot_map.key_ptr = NULL;
147 boot_map.buff_size = &buff_size;
148
149 status = efi_get_memory_map(sys_table_arg, &boot_map);
150 if (status != EFI_SUCCESS)
151 return membase;
152
153 map.map_end = map.map + map_size;
154
155 for_each_efi_memory_desc_in_map(&map, md) {
156 if (md->attribute & EFI_MEMORY_WB) {
157 if (membase > md->phys_addr)
158 membase = md->phys_addr;
159 }
160 }
161
162 efi_call_early(free_pool, map.map);
163
164 return membase;
165}
166
167/*
168 * Allocate at the highest possible address that is not above 'max'.
169 */
170efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
171 unsigned long size, unsigned long align,
172 unsigned long *addr, unsigned long max)
173{
174 unsigned long map_size, desc_size, buff_size;
175 efi_memory_desc_t *map;
176 efi_status_t status;
177 unsigned long nr_pages;
178 u64 max_addr = 0;
179 int i;
180 struct efi_boot_memmap boot_map;
181
182 boot_map.map = ↦
183 boot_map.map_size = &map_size;
184 boot_map.desc_size = &desc_size;
185 boot_map.desc_ver = NULL;
186 boot_map.key_ptr = NULL;
187 boot_map.buff_size = &buff_size;
188
189 status = efi_get_memory_map(sys_table_arg, &boot_map);
190 if (status != EFI_SUCCESS)
191 goto fail;
192
193 /*
194 * Enforce minimum alignment that EFI or Linux requires when
195 * requesting a specific address. We are doing page-based (or
196 * larger) allocations, and both the address and size must meet
197 * alignment constraints.
198 */
199 if (align < EFI_ALLOC_ALIGN)
200 align = EFI_ALLOC_ALIGN;
201
202 size = round_up(size, EFI_ALLOC_ALIGN);
203 nr_pages = size / EFI_PAGE_SIZE;
204again:
205 for (i = 0; i < map_size / desc_size; i++) {
206 efi_memory_desc_t *desc;
207 unsigned long m = (unsigned long)map;
208 u64 start, end;
209
210 desc = efi_early_memdesc_ptr(m, desc_size, i);
211 if (desc->type != EFI_CONVENTIONAL_MEMORY)
212 continue;
213
214 if (desc->num_pages < nr_pages)
215 continue;
216
217 start = desc->phys_addr;
218 end = start + desc->num_pages * EFI_PAGE_SIZE;
219
220 if (end > max)
221 end = max;
222
223 if ((start + size) > end)
224 continue;
225
226 if (round_down(end - size, align) < start)
227 continue;
228
229 start = round_down(end - size, align);
230
231 /*
232 * Don't allocate at 0x0. It will confuse code that
233 * checks pointers against NULL.
234 */
235 if (start == 0x0)
236 continue;
237
238 if (start > max_addr)
239 max_addr = start;
240 }
241
242 if (!max_addr)
243 status = EFI_NOT_FOUND;
244 else {
245 status = efi_call_early(allocate_pages,
246 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
247 nr_pages, &max_addr);
248 if (status != EFI_SUCCESS) {
249 max = max_addr;
250 max_addr = 0;
251 goto again;
252 }
253
254 *addr = max_addr;
255 }
256
257 efi_call_early(free_pool, map);
258fail:
259 return status;
260}
261
262/*
263 * Allocate at the lowest possible address that is not below 'min'.
264 */
265efi_status_t efi_low_alloc_above(efi_system_table_t *sys_table_arg,
266 unsigned long size, unsigned long align,
267 unsigned long *addr, unsigned long min)
268{
269 unsigned long map_size, desc_size, buff_size;
270 efi_memory_desc_t *map;
271 efi_status_t status;
272 unsigned long nr_pages;
273 int i;
274 struct efi_boot_memmap boot_map;
275
276 boot_map.map = ↦
277 boot_map.map_size = &map_size;
278 boot_map.desc_size = &desc_size;
279 boot_map.desc_ver = NULL;
280 boot_map.key_ptr = NULL;
281 boot_map.buff_size = &buff_size;
282
283 status = efi_get_memory_map(sys_table_arg, &boot_map);
284 if (status != EFI_SUCCESS)
285 goto fail;
286
287 /*
288 * Enforce minimum alignment that EFI or Linux requires when
289 * requesting a specific address. We are doing page-based (or
290 * larger) allocations, and both the address and size must meet
291 * alignment constraints.
292 */
293 if (align < EFI_ALLOC_ALIGN)
294 align = EFI_ALLOC_ALIGN;
295
296 size = round_up(size, EFI_ALLOC_ALIGN);
297 nr_pages = size / EFI_PAGE_SIZE;
298 for (i = 0; i < map_size / desc_size; i++) {
299 efi_memory_desc_t *desc;
300 unsigned long m = (unsigned long)map;
301 u64 start, end;
302
303 desc = efi_early_memdesc_ptr(m, desc_size, i);
304
305 if (desc->type != EFI_CONVENTIONAL_MEMORY)
306 continue;
307
308 if (desc->num_pages < nr_pages)
309 continue;
310
311 start = desc->phys_addr;
312 end = start + desc->num_pages * EFI_PAGE_SIZE;
313
314 if (start < min)
315 start = min;
316
317 start = round_up(start, align);
318 if ((start + size) > end)
319 continue;
320
321 status = efi_call_early(allocate_pages,
322 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
323 nr_pages, &start);
324 if (status == EFI_SUCCESS) {
325 *addr = start;
326 break;
327 }
328 }
329
330 if (i == map_size / desc_size)
331 status = EFI_NOT_FOUND;
332
333 efi_call_early(free_pool, map);
334fail:
335 return status;
336}
337
338void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
339 unsigned long addr)
340{
341 unsigned long nr_pages;
342
343 if (!size)
344 return;
345
346 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
347 efi_call_early(free_pages, addr, nr_pages);
348}
349
350static efi_status_t efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
351 efi_char16_t *filename_16, void **handle,
352 u64 *file_sz)
353{
354 efi_file_handle_t *h, *fh = __fh;
355 efi_file_info_t *info;
356 efi_status_t status;
357 efi_guid_t info_guid = EFI_FILE_INFO_ID;
358 unsigned long info_sz;
359
360 status = efi_call_proto(efi_file_handle, open, fh, &h, filename_16,
361 EFI_FILE_MODE_READ, (u64)0);
362 if (status != EFI_SUCCESS) {
363 efi_printk(sys_table_arg, "Failed to open file: ");
364 efi_char16_printk(sys_table_arg, filename_16);
365 efi_printk(sys_table_arg, "\n");
366 return status;
367 }
368
369 *handle = h;
370
371 info_sz = 0;
372 status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
373 &info_sz, NULL);
374 if (status != EFI_BUFFER_TOO_SMALL) {
375 efi_printk(sys_table_arg, "Failed to get file info size\n");
376 return status;
377 }
378
379grow:
380 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
381 info_sz, (void **)&info);
382 if (status != EFI_SUCCESS) {
383 efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
384 return status;
385 }
386
387 status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
388 &info_sz, info);
389 if (status == EFI_BUFFER_TOO_SMALL) {
390 efi_call_early(free_pool, info);
391 goto grow;
392 }
393
394 *file_sz = info->file_size;
395 efi_call_early(free_pool, info);
396
397 if (status != EFI_SUCCESS)
398 efi_printk(sys_table_arg, "Failed to get initrd info\n");
399
400 return status;
401}
402
403static efi_status_t efi_file_read(void *handle, unsigned long *size, void *addr)
404{
405 return efi_call_proto(efi_file_handle, read, handle, size, addr);
406}
407
408static efi_status_t efi_file_close(void *handle)
409{
410 return efi_call_proto(efi_file_handle, close, handle);
411}
412
413static efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
414 efi_loaded_image_t *image,
415 efi_file_handle_t **__fh)
416{
417 efi_file_io_interface_t *io;
418 efi_file_handle_t *fh;
419 efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
420 efi_status_t status;
421 void *handle = (void *)(unsigned long)efi_table_attr(efi_loaded_image,
422 device_handle,
423 image);
424
425 status = efi_call_early(handle_protocol, handle,
426 &fs_proto, (void **)&io);
427 if (status != EFI_SUCCESS) {
428 efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
429 return status;
430 }
431
432 status = efi_call_proto(efi_file_io_interface, open_volume, io, &fh);
433 if (status != EFI_SUCCESS)
434 efi_printk(sys_table_arg, "Failed to open volume\n");
435 else
436 *__fh = fh;
437
438 return status;
439}
440
441/*
442 * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
443 * option, e.g. efi=nochunk.
444 *
445 * It should be noted that efi= is parsed in two very different
446 * environments, first in the early boot environment of the EFI boot
447 * stub, and subsequently during the kernel boot.
448 */
449efi_status_t efi_parse_options(char const *cmdline)
450{
451 char *str;
452
453 str = strstr(cmdline, "nokaslr");
454 if (str == cmdline || (str && str > cmdline && *(str - 1) == ' '))
455 __nokaslr = 1;
456
457 str = strstr(cmdline, "quiet");
458 if (str == cmdline || (str && str > cmdline && *(str - 1) == ' '))
459 __quiet = 1;
460
461 /*
462 * If no EFI parameters were specified on the cmdline we've got
463 * nothing to do.
464 */
465 str = strstr(cmdline, "efi=");
466 if (!str)
467 return EFI_SUCCESS;
468
469 /* Skip ahead to first argument */
470 str += strlen("efi=");
471
472 /*
473 * Remember, because efi= is also used by the kernel we need to
474 * skip over arguments we don't understand.
475 */
476 while (*str && *str != ' ') {
477 if (!strncmp(str, "nochunk", 7)) {
478 str += strlen("nochunk");
479 __chunk_size = -1UL;
480 }
481
482 if (!strncmp(str, "novamap", 7)) {
483 str += strlen("novamap");
484 __novamap = 1;
485 }
486
487 /* Group words together, delimited by "," */
488 while (*str && *str != ' ' && *str != ',')
489 str++;
490
491 if (*str == ',')
492 str++;
493 }
494
495 return EFI_SUCCESS;
496}
497
498/*
499 * Check the cmdline for a LILO-style file= arguments.
500 *
501 * We only support loading a file from the same filesystem as
502 * the kernel image.
503 */
504efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
505 efi_loaded_image_t *image,
506 char *cmd_line, char *option_string,
507 unsigned long max_addr,
508 unsigned long *load_addr,
509 unsigned long *load_size)
510{
511 struct file_info *files;
512 unsigned long file_addr;
513 u64 file_size_total;
514 efi_file_handle_t *fh = NULL;
515 efi_status_t status;
516 int nr_files;
517 char *str;
518 int i, j, k;
519
520 file_addr = 0;
521 file_size_total = 0;
522
523 str = cmd_line;
524
525 j = 0; /* See close_handles */
526
527 if (!load_addr || !load_size)
528 return EFI_INVALID_PARAMETER;
529
530 *load_addr = 0;
531 *load_size = 0;
532
533 if (!str || !*str)
534 return EFI_SUCCESS;
535
536 for (nr_files = 0; *str; nr_files++) {
537 str = strstr(str, option_string);
538 if (!str)
539 break;
540
541 str += strlen(option_string);
542
543 /* Skip any leading slashes */
544 while (*str == '/' || *str == '\\')
545 str++;
546
547 while (*str && *str != ' ' && *str != '\n')
548 str++;
549 }
550
551 if (!nr_files)
552 return EFI_SUCCESS;
553
554 status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
555 nr_files * sizeof(*files), (void **)&files);
556 if (status != EFI_SUCCESS) {
557 pr_efi_err(sys_table_arg, "Failed to alloc mem for file handle list\n");
558 goto fail;
559 }
560
561 str = cmd_line;
562 for (i = 0; i < nr_files; i++) {
563 struct file_info *file;
564 efi_char16_t filename_16[256];
565 efi_char16_t *p;
566
567 str = strstr(str, option_string);
568 if (!str)
569 break;
570
571 str += strlen(option_string);
572
573 file = &files[i];
574 p = filename_16;
575
576 /* Skip any leading slashes */
577 while (*str == '/' || *str == '\\')
578 str++;
579
580 while (*str && *str != ' ' && *str != '\n') {
581 if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16))
582 break;
583
584 if (*str == '/') {
585 *p++ = '\\';
586 str++;
587 } else {
588 *p++ = *str++;
589 }
590 }
591
592 *p = '\0';
593
594 /* Only open the volume once. */
595 if (!i) {
596 status = efi_open_volume(sys_table_arg, image, &fh);
597 if (status != EFI_SUCCESS)
598 goto free_files;
599 }
600
601 status = efi_file_size(sys_table_arg, fh, filename_16,
602 (void **)&file->handle, &file->size);
603 if (status != EFI_SUCCESS)
604 goto close_handles;
605
606 file_size_total += file->size;
607 }
608
609 if (file_size_total) {
610 unsigned long addr;
611
612 /*
613 * Multiple files need to be at consecutive addresses in memory,
614 * so allocate enough memory for all the files. This is used
615 * for loading multiple files.
616 */
617 status = efi_high_alloc(sys_table_arg, file_size_total, 0x1000,
618 &file_addr, max_addr);
619 if (status != EFI_SUCCESS) {
620 pr_efi_err(sys_table_arg, "Failed to alloc highmem for files\n");
621 goto close_handles;
622 }
623
624 /* We've run out of free low memory. */
625 if (file_addr > max_addr) {
626 pr_efi_err(sys_table_arg, "We've run out of free low memory\n");
627 status = EFI_INVALID_PARAMETER;
628 goto free_file_total;
629 }
630
631 addr = file_addr;
632 for (j = 0; j < nr_files; j++) {
633 unsigned long size;
634
635 size = files[j].size;
636 while (size) {
637 unsigned long chunksize;
638
639 if (IS_ENABLED(CONFIG_X86) && size > __chunk_size)
640 chunksize = __chunk_size;
641 else
642 chunksize = size;
643
644 status = efi_file_read(files[j].handle,
645 &chunksize,
646 (void *)addr);
647 if (status != EFI_SUCCESS) {
648 pr_efi_err(sys_table_arg, "Failed to read file\n");
649 goto free_file_total;
650 }
651 addr += chunksize;
652 size -= chunksize;
653 }
654
655 efi_file_close(files[j].handle);
656 }
657
658 }
659
660 efi_call_early(free_pool, files);
661
662 *load_addr = file_addr;
663 *load_size = file_size_total;
664
665 return status;
666
667free_file_total:
668 efi_free(sys_table_arg, file_size_total, file_addr);
669
670close_handles:
671 for (k = j; k < i; k++)
672 efi_file_close(files[k].handle);
673free_files:
674 efi_call_early(free_pool, files);
675fail:
676 *load_addr = 0;
677 *load_size = 0;
678
679 return status;
680}
681/*
682 * Relocate a kernel image, either compressed or uncompressed.
683 * In the ARM64 case, all kernel images are currently
684 * uncompressed, and as such when we relocate it we need to
685 * allocate additional space for the BSS segment. Any low
686 * memory that this function should avoid needs to be
687 * unavailable in the EFI memory map, as if the preferred
688 * address is not available the lowest available address will
689 * be used.
690 */
691efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
692 unsigned long *image_addr,
693 unsigned long image_size,
694 unsigned long alloc_size,
695 unsigned long preferred_addr,
696 unsigned long alignment,
697 unsigned long min_addr)
698{
699 unsigned long cur_image_addr;
700 unsigned long new_addr = 0;
701 efi_status_t status;
702 unsigned long nr_pages;
703 efi_physical_addr_t efi_addr = preferred_addr;
704
705 if (!image_addr || !image_size || !alloc_size)
706 return EFI_INVALID_PARAMETER;
707 if (alloc_size < image_size)
708 return EFI_INVALID_PARAMETER;
709
710 cur_image_addr = *image_addr;
711
712 /*
713 * The EFI firmware loader could have placed the kernel image
714 * anywhere in memory, but the kernel has restrictions on the
715 * max physical address it can run at. Some architectures
716 * also have a prefered address, so first try to relocate
717 * to the preferred address. If that fails, allocate as low
718 * as possible while respecting the required alignment.
719 */
720 nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
721 status = efi_call_early(allocate_pages,
722 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
723 nr_pages, &efi_addr);
724 new_addr = efi_addr;
725 /*
726 * If preferred address allocation failed allocate as low as
727 * possible.
728 */
729 if (status != EFI_SUCCESS) {
730 status = efi_low_alloc_above(sys_table_arg, alloc_size,
731 alignment, &new_addr, min_addr);
732 }
733 if (status != EFI_SUCCESS) {
734 pr_efi_err(sys_table_arg, "Failed to allocate usable memory for kernel.\n");
735 return status;
736 }
737
738 /*
739 * We know source/dest won't overlap since both memory ranges
740 * have been allocated by UEFI, so we can safely use memcpy.
741 */
742 memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
743
744 /* Return the new address of the relocated image. */
745 *image_addr = new_addr;
746
747 return status;
748}
749
750/*
751 * Get the number of UTF-8 bytes corresponding to an UTF-16 character.
752 * This overestimates for surrogates, but that is okay.
753 */
754static int efi_utf8_bytes(u16 c)
755{
756 return 1 + (c >= 0x80) + (c >= 0x800);
757}
758
759/*
760 * Convert an UTF-16 string, not necessarily null terminated, to UTF-8.
761 */
762static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n)
763{
764 unsigned int c;
765
766 while (n--) {
767 c = *src++;
768 if (n && c >= 0xd800 && c <= 0xdbff &&
769 *src >= 0xdc00 && *src <= 0xdfff) {
770 c = 0x10000 + ((c & 0x3ff) << 10) + (*src & 0x3ff);
771 src++;
772 n--;
773 }
774 if (c >= 0xd800 && c <= 0xdfff)
775 c = 0xfffd; /* Unmatched surrogate */
776 if (c < 0x80) {
777 *dst++ = c;
778 continue;
779 }
780 if (c < 0x800) {
781 *dst++ = 0xc0 + (c >> 6);
782 goto t1;
783 }
784 if (c < 0x10000) {
785 *dst++ = 0xe0 + (c >> 12);
786 goto t2;
787 }
788 *dst++ = 0xf0 + (c >> 18);
789 *dst++ = 0x80 + ((c >> 12) & 0x3f);
790 t2:
791 *dst++ = 0x80 + ((c >> 6) & 0x3f);
792 t1:
793 *dst++ = 0x80 + (c & 0x3f);
794 }
795
796 return dst;
797}
798
799#ifndef MAX_CMDLINE_ADDRESS
800#define MAX_CMDLINE_ADDRESS ULONG_MAX
801#endif
802
803/*
804 * Convert the unicode UEFI command line to ASCII to pass to kernel.
805 * Size of memory allocated return in *cmd_line_len.
806 * Returns NULL on error.
807 */
808char *efi_convert_cmdline(efi_system_table_t *sys_table_arg,
809 efi_loaded_image_t *image,
810 int *cmd_line_len)
811{
812 const u16 *s2;
813 u8 *s1 = NULL;
814 unsigned long cmdline_addr = 0;
815 int load_options_chars = image->load_options_size / 2; /* UTF-16 */
816 const u16 *options = image->load_options;
817 int options_bytes = 0; /* UTF-8 bytes */
818 int options_chars = 0; /* UTF-16 chars */
819 efi_status_t status;
820 u16 zero = 0;
821
822 if (options) {
823 s2 = options;
824 while (*s2 && *s2 != '\n'
825 && options_chars < load_options_chars) {
826 options_bytes += efi_utf8_bytes(*s2++);
827 options_chars++;
828 }
829 }
830
831 if (!options_chars) {
832 /* No command line options, so return empty string*/
833 options = &zero;
834 }
835
836 options_bytes++; /* NUL termination */
837
838 status = efi_high_alloc(sys_table_arg, options_bytes, 0,
839 &cmdline_addr, MAX_CMDLINE_ADDRESS);
840 if (status != EFI_SUCCESS)
841 return NULL;
842
843 s1 = (u8 *)cmdline_addr;
844 s2 = (const u16 *)options;
845
846 s1 = efi_utf16_to_utf8(s1, s2, options_chars);
847 *s1 = '\0';
848
849 *cmd_line_len = options_bytes;
850 return (char *)cmdline_addr;
851}
852
853/*
854 * Handle calling ExitBootServices according to the requirements set out by the
855 * spec. Obtains the current memory map, and returns that info after calling
856 * ExitBootServices. The client must specify a function to perform any
857 * processing of the memory map data prior to ExitBootServices. A client
858 * specific structure may be passed to the function via priv. The client
859 * function may be called multiple times.
860 */
861efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table_arg,
862 void *handle,
863 struct efi_boot_memmap *map,
864 void *priv,
865 efi_exit_boot_map_processing priv_func)
866{
867 efi_status_t status;
868
869 status = efi_get_memory_map(sys_table_arg, map);
870
871 if (status != EFI_SUCCESS)
872 goto fail;
873
874 status = priv_func(sys_table_arg, map, priv);
875 if (status != EFI_SUCCESS)
876 goto free_map;
877
878 status = efi_call_early(exit_boot_services, handle, *map->key_ptr);
879
880 if (status == EFI_INVALID_PARAMETER) {
881 /*
882 * The memory map changed between efi_get_memory_map() and
883 * exit_boot_services(). Per the UEFI Spec v2.6, Section 6.4:
884 * EFI_BOOT_SERVICES.ExitBootServices we need to get the
885 * updated map, and try again. The spec implies one retry
886 * should be sufficent, which is confirmed against the EDK2
887 * implementation. Per the spec, we can only invoke
888 * get_memory_map() and exit_boot_services() - we cannot alloc
889 * so efi_get_memory_map() cannot be used, and we must reuse
890 * the buffer. For all practical purposes, the headroom in the
891 * buffer should account for any changes in the map so the call
892 * to get_memory_map() is expected to succeed here.
893 */
894 *map->map_size = *map->buff_size;
895 status = efi_call_early(get_memory_map,
896 map->map_size,
897 *map->map,
898 map->key_ptr,
899 map->desc_size,
900 map->desc_ver);
901
902 /* exit_boot_services() was called, thus cannot free */
903 if (status != EFI_SUCCESS)
904 goto fail;
905
906 status = priv_func(sys_table_arg, map, priv);
907 /* exit_boot_services() was called, thus cannot free */
908 if (status != EFI_SUCCESS)
909 goto fail;
910
911 status = efi_call_early(exit_boot_services, handle, *map->key_ptr);
912 }
913
914 /* exit_boot_services() was called, thus cannot free */
915 if (status != EFI_SUCCESS)
916 goto fail;
917
918 return EFI_SUCCESS;
919
920free_map:
921 efi_call_early(free_pool, *map->map);
922fail:
923 return status;
924}
925
926#define GET_EFI_CONFIG_TABLE(bits) \
927static void *get_efi_config_table##bits(efi_system_table_t *_sys_table, \
928 efi_guid_t guid) \
929{ \
930 efi_system_table_##bits##_t *sys_table; \
931 efi_config_table_##bits##_t *tables; \
932 int i; \
933 \
934 sys_table = (typeof(sys_table))_sys_table; \
935 tables = (typeof(tables))(unsigned long)sys_table->tables; \
936 \
937 for (i = 0; i < sys_table->nr_tables; i++) { \
938 if (efi_guidcmp(tables[i].guid, guid) != 0) \
939 continue; \
940 \
941 return (void *)(unsigned long)tables[i].table; \
942 } \
943 \
944 return NULL; \
945}
946GET_EFI_CONFIG_TABLE(32)
947GET_EFI_CONFIG_TABLE(64)
948
949void *get_efi_config_table(efi_system_table_t *sys_table, efi_guid_t guid)
950{
951 if (efi_is_64bit())
952 return get_efi_config_table64(sys_table, guid);
953 else
954 return get_efi_config_table32(sys_table, guid);
955}