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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Kexec bzImage loader
4 *
5 * Copyright (C) 2014 Red Hat Inc.
6 * Authors:
7 * Vivek Goyal <vgoyal@redhat.com>
8 */
9
10#define pr_fmt(fmt) "kexec-bzImage64: " fmt
11
12#include <linux/string.h>
13#include <linux/printk.h>
14#include <linux/errno.h>
15#include <linux/slab.h>
16#include <linux/kexec.h>
17#include <linux/kernel.h>
18#include <linux/mm.h>
19#include <linux/efi.h>
20#include <linux/verification.h>
21
22#include <asm/bootparam.h>
23#include <asm/setup.h>
24#include <asm/crash.h>
25#include <asm/efi.h>
26#include <asm/e820/api.h>
27#include <asm/kexec-bzimage64.h>
28
29#define MAX_ELFCOREHDR_STR_LEN 30 /* elfcorehdr=0x<64bit-value> */
30
31/*
32 * Defines lowest physical address for various segments. Not sure where
33 * exactly these limits came from. Current bzimage64 loader in kexec-tools
34 * uses these so I am retaining it. It can be changed over time as we gain
35 * more insight.
36 */
37#define MIN_PURGATORY_ADDR 0x3000
38#define MIN_BOOTPARAM_ADDR 0x3000
39#define MIN_KERNEL_LOAD_ADDR 0x100000
40#define MIN_INITRD_LOAD_ADDR 0x1000000
41
42/*
43 * This is a place holder for all boot loader specific data structure which
44 * gets allocated in one call but gets freed much later during cleanup
45 * time. Right now there is only one field but it can grow as need be.
46 */
47struct bzimage64_data {
48 /*
49 * Temporary buffer to hold bootparams buffer. This should be
50 * freed once the bootparam segment has been loaded.
51 */
52 void *bootparams_buf;
53};
54
55static int setup_initrd(struct boot_params *params,
56 unsigned long initrd_load_addr, unsigned long initrd_len)
57{
58 params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL;
59 params->hdr.ramdisk_size = initrd_len & 0xffffffffUL;
60
61 params->ext_ramdisk_image = initrd_load_addr >> 32;
62 params->ext_ramdisk_size = initrd_len >> 32;
63
64 return 0;
65}
66
67static int setup_cmdline(struct kimage *image, struct boot_params *params,
68 unsigned long bootparams_load_addr,
69 unsigned long cmdline_offset, char *cmdline,
70 unsigned long cmdline_len)
71{
72 char *cmdline_ptr = ((char *)params) + cmdline_offset;
73 unsigned long cmdline_ptr_phys, len = 0;
74 uint32_t cmdline_low_32, cmdline_ext_32;
75
76 if (image->type == KEXEC_TYPE_CRASH) {
77 len = sprintf(cmdline_ptr,
78 "elfcorehdr=0x%lx ", image->arch.elf_load_addr);
79 }
80 memcpy(cmdline_ptr + len, cmdline, cmdline_len);
81 cmdline_len += len;
82
83 cmdline_ptr[cmdline_len - 1] = '\0';
84
85 pr_debug("Final command line is: %s\n", cmdline_ptr);
86 cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
87 cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
88 cmdline_ext_32 = cmdline_ptr_phys >> 32;
89
90 params->hdr.cmd_line_ptr = cmdline_low_32;
91 if (cmdline_ext_32)
92 params->ext_cmd_line_ptr = cmdline_ext_32;
93
94 return 0;
95}
96
97static int setup_e820_entries(struct boot_params *params)
98{
99 unsigned int nr_e820_entries;
100
101 nr_e820_entries = e820_table_kexec->nr_entries;
102
103 /* TODO: Pass entries more than E820_MAX_ENTRIES_ZEROPAGE in bootparams setup data */
104 if (nr_e820_entries > E820_MAX_ENTRIES_ZEROPAGE)
105 nr_e820_entries = E820_MAX_ENTRIES_ZEROPAGE;
106
107 params->e820_entries = nr_e820_entries;
108 memcpy(¶ms->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry));
109
110 return 0;
111}
112
113#ifdef CONFIG_EFI
114static int setup_efi_info_memmap(struct boot_params *params,
115 unsigned long params_load_addr,
116 unsigned int efi_map_offset,
117 unsigned int efi_map_sz)
118{
119 void *efi_map = (void *)params + efi_map_offset;
120 unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
121 struct efi_info *ei = ¶ms->efi_info;
122
123 if (!efi_map_sz)
124 return 0;
125
126 efi_runtime_map_copy(efi_map, efi_map_sz);
127
128 ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
129 ei->efi_memmap_hi = efi_map_phys_addr >> 32;
130 ei->efi_memmap_size = efi_map_sz;
131
132 return 0;
133}
134
135static int
136prepare_add_efi_setup_data(struct boot_params *params,
137 unsigned long params_load_addr,
138 unsigned int efi_setup_data_offset)
139{
140 unsigned long setup_data_phys;
141 struct setup_data *sd = (void *)params + efi_setup_data_offset;
142 struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
143
144 esd->fw_vendor = efi_fw_vendor;
145 esd->tables = efi_config_table;
146 esd->smbios = efi.smbios;
147
148 sd->type = SETUP_EFI;
149 sd->len = sizeof(struct efi_setup_data);
150
151 /* Add setup data */
152 setup_data_phys = params_load_addr + efi_setup_data_offset;
153 sd->next = params->hdr.setup_data;
154 params->hdr.setup_data = setup_data_phys;
155
156 return 0;
157}
158
159static int
160setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
161 unsigned int efi_map_offset, unsigned int efi_map_sz,
162 unsigned int efi_setup_data_offset)
163{
164 struct efi_info *current_ei = &boot_params.efi_info;
165 struct efi_info *ei = ¶ms->efi_info;
166
167 if (!efi_enabled(EFI_RUNTIME_SERVICES))
168 return 0;
169
170 if (!current_ei->efi_memmap_size)
171 return 0;
172
173 params->secure_boot = boot_params.secure_boot;
174 ei->efi_loader_signature = current_ei->efi_loader_signature;
175 ei->efi_systab = current_ei->efi_systab;
176 ei->efi_systab_hi = current_ei->efi_systab_hi;
177
178 ei->efi_memdesc_version = current_ei->efi_memdesc_version;
179 ei->efi_memdesc_size = efi_get_runtime_map_desc_size();
180
181 setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
182 efi_map_sz);
183 prepare_add_efi_setup_data(params, params_load_addr,
184 efi_setup_data_offset);
185 return 0;
186}
187#endif /* CONFIG_EFI */
188
189static int
190setup_boot_parameters(struct kimage *image, struct boot_params *params,
191 unsigned long params_load_addr,
192 unsigned int efi_map_offset, unsigned int efi_map_sz,
193 unsigned int efi_setup_data_offset)
194{
195 unsigned int nr_e820_entries;
196 unsigned long long mem_k, start, end;
197 int i, ret = 0;
198
199 /* Get subarch from existing bootparams */
200 params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
201
202 /* Copying screen_info will do? */
203 memcpy(¶ms->screen_info, &boot_params.screen_info,
204 sizeof(struct screen_info));
205
206 /* Fill in memsize later */
207 params->screen_info.ext_mem_k = 0;
208 params->alt_mem_k = 0;
209
210 /* Always fill in RSDP: it is either 0 or a valid value */
211 params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr;
212
213 /* Default APM info */
214 memset(¶ms->apm_bios_info, 0, sizeof(params->apm_bios_info));
215
216 /* Default drive info */
217 memset(¶ms->hd0_info, 0, sizeof(params->hd0_info));
218 memset(¶ms->hd1_info, 0, sizeof(params->hd1_info));
219
220 if (image->type == KEXEC_TYPE_CRASH) {
221 ret = crash_setup_memmap_entries(image, params);
222 if (ret)
223 return ret;
224 } else
225 setup_e820_entries(params);
226
227 nr_e820_entries = params->e820_entries;
228
229 for (i = 0; i < nr_e820_entries; i++) {
230 if (params->e820_table[i].type != E820_TYPE_RAM)
231 continue;
232 start = params->e820_table[i].addr;
233 end = params->e820_table[i].addr + params->e820_table[i].size - 1;
234
235 if ((start <= 0x100000) && end > 0x100000) {
236 mem_k = (end >> 10) - (0x100000 >> 10);
237 params->screen_info.ext_mem_k = mem_k;
238 params->alt_mem_k = mem_k;
239 if (mem_k > 0xfc00)
240 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
241 if (mem_k > 0xffffffff)
242 params->alt_mem_k = 0xffffffff;
243 }
244 }
245
246#ifdef CONFIG_EFI
247 /* Setup EFI state */
248 setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
249 efi_setup_data_offset);
250#endif
251 /* Setup EDD info */
252 memcpy(params->eddbuf, boot_params.eddbuf,
253 EDDMAXNR * sizeof(struct edd_info));
254 params->eddbuf_entries = boot_params.eddbuf_entries;
255
256 memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
257 EDD_MBR_SIG_MAX * sizeof(unsigned int));
258
259 return ret;
260}
261
262static int bzImage64_probe(const char *buf, unsigned long len)
263{
264 int ret = -ENOEXEC;
265 struct setup_header *header;
266
267 /* kernel should be at least two sectors long */
268 if (len < 2 * 512) {
269 pr_err("File is too short to be a bzImage\n");
270 return ret;
271 }
272
273 header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
274 if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
275 pr_err("Not a bzImage\n");
276 return ret;
277 }
278
279 if (header->boot_flag != 0xAA55) {
280 pr_err("No x86 boot sector present\n");
281 return ret;
282 }
283
284 if (header->version < 0x020C) {
285 pr_err("Must be at least protocol version 2.12\n");
286 return ret;
287 }
288
289 if (!(header->loadflags & LOADED_HIGH)) {
290 pr_err("zImage not a bzImage\n");
291 return ret;
292 }
293
294 if (!(header->xloadflags & XLF_KERNEL_64)) {
295 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
296 return ret;
297 }
298
299 if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
300 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
301 return ret;
302 }
303
304 /*
305 * Can't handle 32bit EFI as it does not allow loading kernel
306 * above 4G. This should be handled by 32bit bzImage loader
307 */
308 if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
309 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
310 return ret;
311 }
312
313 if (!(header->xloadflags & XLF_5LEVEL) && pgtable_l5_enabled()) {
314 pr_err("bzImage cannot handle 5-level paging mode.\n");
315 return ret;
316 }
317
318 /* I've got a bzImage */
319 pr_debug("It's a relocatable bzImage64\n");
320 ret = 0;
321
322 return ret;
323}
324
325static void *bzImage64_load(struct kimage *image, char *kernel,
326 unsigned long kernel_len, char *initrd,
327 unsigned long initrd_len, char *cmdline,
328 unsigned long cmdline_len)
329{
330
331 struct setup_header *header;
332 int setup_sects, kern16_size, ret = 0;
333 unsigned long setup_header_size, params_cmdline_sz;
334 struct boot_params *params;
335 unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
336 struct bzimage64_data *ldata;
337 struct kexec_entry64_regs regs64;
338 void *stack;
339 unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
340 unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
341 struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
342 .top_down = true };
343 struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR,
344 .buf_max = ULONG_MAX, .top_down = true };
345
346 header = (struct setup_header *)(kernel + setup_hdr_offset);
347 setup_sects = header->setup_sects;
348 if (setup_sects == 0)
349 setup_sects = 4;
350
351 kern16_size = (setup_sects + 1) * 512;
352 if (kernel_len < kern16_size) {
353 pr_err("bzImage truncated\n");
354 return ERR_PTR(-ENOEXEC);
355 }
356
357 if (cmdline_len > header->cmdline_size) {
358 pr_err("Kernel command line too long\n");
359 return ERR_PTR(-EINVAL);
360 }
361
362 /*
363 * In case of crash dump, we will append elfcorehdr=<addr> to
364 * command line. Make sure it does not overflow
365 */
366 if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
367 pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
368 return ERR_PTR(-EINVAL);
369 }
370
371 /* Allocate and load backup region */
372 if (image->type == KEXEC_TYPE_CRASH) {
373 ret = crash_load_segments(image);
374 if (ret)
375 return ERR_PTR(ret);
376 }
377
378 /*
379 * Load purgatory. For 64bit entry point, purgatory code can be
380 * anywhere.
381 */
382 ret = kexec_load_purgatory(image, &pbuf);
383 if (ret) {
384 pr_err("Loading purgatory failed\n");
385 return ERR_PTR(ret);
386 }
387
388 pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem);
389
390
391 /*
392 * Load Bootparams and cmdline and space for efi stuff.
393 *
394 * Allocate memory together for multiple data structures so
395 * that they all can go in single area/segment and we don't
396 * have to create separate segment for each. Keeps things
397 * little bit simple
398 */
399 efi_map_sz = efi_get_runtime_map_size();
400 params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
401 MAX_ELFCOREHDR_STR_LEN;
402 params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
403 kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
404 sizeof(struct setup_data) +
405 sizeof(struct efi_setup_data);
406
407 params = kzalloc(kbuf.bufsz, GFP_KERNEL);
408 if (!params)
409 return ERR_PTR(-ENOMEM);
410 efi_map_offset = params_cmdline_sz;
411 efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);
412
413 /* Copy setup header onto bootparams. Documentation/x86/boot.rst */
414 setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
415
416 /* Is there a limit on setup header size? */
417 memcpy(¶ms->hdr, (kernel + setup_hdr_offset), setup_header_size);
418
419 kbuf.buffer = params;
420 kbuf.memsz = kbuf.bufsz;
421 kbuf.buf_align = 16;
422 kbuf.buf_min = MIN_BOOTPARAM_ADDR;
423 ret = kexec_add_buffer(&kbuf);
424 if (ret)
425 goto out_free_params;
426 bootparam_load_addr = kbuf.mem;
427 pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
428 bootparam_load_addr, kbuf.bufsz, kbuf.bufsz);
429
430 /* Load kernel */
431 kbuf.buffer = kernel + kern16_size;
432 kbuf.bufsz = kernel_len - kern16_size;
433 kbuf.memsz = PAGE_ALIGN(header->init_size);
434 kbuf.buf_align = header->kernel_alignment;
435 kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
436 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
437 ret = kexec_add_buffer(&kbuf);
438 if (ret)
439 goto out_free_params;
440 kernel_load_addr = kbuf.mem;
441
442 pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
443 kernel_load_addr, kbuf.bufsz, kbuf.memsz);
444
445 /* Load initrd high */
446 if (initrd) {
447 kbuf.buffer = initrd;
448 kbuf.bufsz = kbuf.memsz = initrd_len;
449 kbuf.buf_align = PAGE_SIZE;
450 kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
451 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
452 ret = kexec_add_buffer(&kbuf);
453 if (ret)
454 goto out_free_params;
455 initrd_load_addr = kbuf.mem;
456
457 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
458 initrd_load_addr, initrd_len, initrd_len);
459
460 setup_initrd(params, initrd_load_addr, initrd_len);
461 }
462
463 setup_cmdline(image, params, bootparam_load_addr,
464 sizeof(struct boot_params), cmdline, cmdline_len);
465
466 /* bootloader info. Do we need a separate ID for kexec kernel loader? */
467 params->hdr.type_of_loader = 0x0D << 4;
468 params->hdr.loadflags = 0;
469
470 /* Setup purgatory regs for entry */
471 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64,
472 sizeof(regs64), 1);
473 if (ret)
474 goto out_free_params;
475
476 regs64.rbx = 0; /* Bootstrap Processor */
477 regs64.rsi = bootparam_load_addr;
478 regs64.rip = kernel_load_addr + 0x200;
479 stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
480 if (IS_ERR(stack)) {
481 pr_err("Could not find address of symbol stack_end\n");
482 ret = -EINVAL;
483 goto out_free_params;
484 }
485
486 regs64.rsp = (unsigned long)stack;
487 ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", ®s64,
488 sizeof(regs64), 0);
489 if (ret)
490 goto out_free_params;
491
492 ret = setup_boot_parameters(image, params, bootparam_load_addr,
493 efi_map_offset, efi_map_sz,
494 efi_setup_data_offset);
495 if (ret)
496 goto out_free_params;
497
498 /* Allocate loader specific data */
499 ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
500 if (!ldata) {
501 ret = -ENOMEM;
502 goto out_free_params;
503 }
504
505 /*
506 * Store pointer to params so that it could be freed after loading
507 * params segment has been loaded and contents have been copied
508 * somewhere else.
509 */
510 ldata->bootparams_buf = params;
511 return ldata;
512
513out_free_params:
514 kfree(params);
515 return ERR_PTR(ret);
516}
517
518/* This cleanup function is called after various segments have been loaded */
519static int bzImage64_cleanup(void *loader_data)
520{
521 struct bzimage64_data *ldata = loader_data;
522
523 if (!ldata)
524 return 0;
525
526 kfree(ldata->bootparams_buf);
527 ldata->bootparams_buf = NULL;
528
529 return 0;
530}
531
532#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
533static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
534{
535 int ret;
536
537 ret = verify_pefile_signature(kernel, kernel_len,
538 VERIFY_USE_SECONDARY_KEYRING,
539 VERIFYING_KEXEC_PE_SIGNATURE);
540 if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
541 ret = verify_pefile_signature(kernel, kernel_len,
542 VERIFY_USE_PLATFORM_KEYRING,
543 VERIFYING_KEXEC_PE_SIGNATURE);
544 }
545 return ret;
546}
547#endif
548
549const struct kexec_file_ops kexec_bzImage64_ops = {
550 .probe = bzImage64_probe,
551 .load = bzImage64_load,
552 .cleanup = bzImage64_cleanup,
553#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
554 .verify_sig = bzImage64_verify_sig,
555#endif
556};