Linux 6.10-rc1
[sfrench/cifs-2.6.git] / arch / x86 / kernel / kexec-bzimage64.c
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/random.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  */
47 struct 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
55 static 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
67 static 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->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         kexec_dprintk("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
97 static 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(&params->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry));
109
110         return 0;
111 }
112
113 enum { RNG_SEED_LENGTH = 32 };
114
115 static void
116 setup_rng_seed(struct boot_params *params, unsigned long params_load_addr,
117                unsigned int rng_seed_setup_data_offset)
118 {
119         struct setup_data *sd = (void *)params + rng_seed_setup_data_offset;
120         unsigned long setup_data_phys;
121
122         if (!rng_is_initialized())
123                 return;
124
125         sd->type = SETUP_RNG_SEED;
126         sd->len = RNG_SEED_LENGTH;
127         get_random_bytes(sd->data, RNG_SEED_LENGTH);
128         setup_data_phys = params_load_addr + rng_seed_setup_data_offset;
129         sd->next = params->hdr.setup_data;
130         params->hdr.setup_data = setup_data_phys;
131 }
132
133 #ifdef CONFIG_EFI
134 static int setup_efi_info_memmap(struct boot_params *params,
135                                   unsigned long params_load_addr,
136                                   unsigned int efi_map_offset,
137                                   unsigned int efi_map_sz)
138 {
139         void *efi_map = (void *)params + efi_map_offset;
140         unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
141         struct efi_info *ei = &params->efi_info;
142
143         if (!efi_map_sz)
144                 return 0;
145
146         efi_runtime_map_copy(efi_map, efi_map_sz);
147
148         ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
149         ei->efi_memmap_hi = efi_map_phys_addr >> 32;
150         ei->efi_memmap_size = efi_map_sz;
151
152         return 0;
153 }
154
155 static int
156 prepare_add_efi_setup_data(struct boot_params *params,
157                        unsigned long params_load_addr,
158                        unsigned int efi_setup_data_offset)
159 {
160         unsigned long setup_data_phys;
161         struct setup_data *sd = (void *)params + efi_setup_data_offset;
162         struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
163
164         esd->fw_vendor = efi_fw_vendor;
165         esd->tables = efi_config_table;
166         esd->smbios = efi.smbios;
167
168         sd->type = SETUP_EFI;
169         sd->len = sizeof(struct efi_setup_data);
170
171         /* Add setup data */
172         setup_data_phys = params_load_addr + efi_setup_data_offset;
173         sd->next = params->hdr.setup_data;
174         params->hdr.setup_data = setup_data_phys;
175
176         return 0;
177 }
178
179 static int
180 setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
181                 unsigned int efi_map_offset, unsigned int efi_map_sz,
182                 unsigned int efi_setup_data_offset)
183 {
184         struct efi_info *current_ei = &boot_params.efi_info;
185         struct efi_info *ei = &params->efi_info;
186
187         if (!efi_enabled(EFI_RUNTIME_SERVICES))
188                 return 0;
189
190         if (!current_ei->efi_memmap_size)
191                 return 0;
192
193         params->secure_boot = boot_params.secure_boot;
194         ei->efi_loader_signature = current_ei->efi_loader_signature;
195         ei->efi_systab = current_ei->efi_systab;
196         ei->efi_systab_hi = current_ei->efi_systab_hi;
197
198         ei->efi_memdesc_version = current_ei->efi_memdesc_version;
199         ei->efi_memdesc_size = efi_get_runtime_map_desc_size();
200
201         setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
202                               efi_map_sz);
203         prepare_add_efi_setup_data(params, params_load_addr,
204                                    efi_setup_data_offset);
205         return 0;
206 }
207 #endif /* CONFIG_EFI */
208
209 static void
210 setup_ima_state(const struct kimage *image, struct boot_params *params,
211                 unsigned long params_load_addr,
212                 unsigned int ima_setup_data_offset)
213 {
214 #ifdef CONFIG_IMA_KEXEC
215         struct setup_data *sd = (void *)params + ima_setup_data_offset;
216         unsigned long setup_data_phys;
217         struct ima_setup_data *ima;
218
219         if (!image->ima_buffer_size)
220                 return;
221
222         sd->type = SETUP_IMA;
223         sd->len = sizeof(*ima);
224
225         ima = (void *)sd + sizeof(struct setup_data);
226         ima->addr = image->ima_buffer_addr;
227         ima->size = image->ima_buffer_size;
228
229         /* Add setup data */
230         setup_data_phys = params_load_addr + ima_setup_data_offset;
231         sd->next = params->hdr.setup_data;
232         params->hdr.setup_data = setup_data_phys;
233 #endif /* CONFIG_IMA_KEXEC */
234 }
235
236 static int
237 setup_boot_parameters(struct kimage *image, struct boot_params *params,
238                       unsigned long params_load_addr,
239                       unsigned int efi_map_offset, unsigned int efi_map_sz,
240                       unsigned int setup_data_offset)
241 {
242         unsigned int nr_e820_entries;
243         unsigned long long mem_k, start, end;
244         int i, ret = 0;
245
246         /* Get subarch from existing bootparams */
247         params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
248
249         /* Copying screen_info will do? */
250         memcpy(&params->screen_info, &screen_info, sizeof(struct screen_info));
251
252         /* Fill in memsize later */
253         params->screen_info.ext_mem_k = 0;
254         params->alt_mem_k = 0;
255
256         /* Always fill in RSDP: it is either 0 or a valid value */
257         params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr;
258
259         /* Default APM info */
260         memset(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));
261
262         /* Default drive info */
263         memset(&params->hd0_info, 0, sizeof(params->hd0_info));
264         memset(&params->hd1_info, 0, sizeof(params->hd1_info));
265
266 #ifdef CONFIG_CRASH_DUMP
267         if (image->type == KEXEC_TYPE_CRASH) {
268                 ret = crash_setup_memmap_entries(image, params);
269                 if (ret)
270                         return ret;
271         } else
272 #endif
273                 setup_e820_entries(params);
274
275         nr_e820_entries = params->e820_entries;
276
277         kexec_dprintk("E820 memmap:\n");
278         for (i = 0; i < nr_e820_entries; i++) {
279                 kexec_dprintk("%016llx-%016llx (%d)\n",
280                               params->e820_table[i].addr,
281                               params->e820_table[i].addr + params->e820_table[i].size - 1,
282                               params->e820_table[i].type);
283                 if (params->e820_table[i].type != E820_TYPE_RAM)
284                         continue;
285                 start = params->e820_table[i].addr;
286                 end = params->e820_table[i].addr + params->e820_table[i].size - 1;
287
288                 if ((start <= 0x100000) && end > 0x100000) {
289                         mem_k = (end >> 10) - (0x100000 >> 10);
290                         params->screen_info.ext_mem_k = mem_k;
291                         params->alt_mem_k = mem_k;
292                         if (mem_k > 0xfc00)
293                                 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
294                         if (mem_k > 0xffffffff)
295                                 params->alt_mem_k = 0xffffffff;
296                 }
297         }
298
299 #ifdef CONFIG_EFI
300         /* Setup EFI state */
301         setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
302                         setup_data_offset);
303         setup_data_offset += sizeof(struct setup_data) +
304                         sizeof(struct efi_setup_data);
305 #endif
306
307         if (IS_ENABLED(CONFIG_IMA_KEXEC)) {
308                 /* Setup IMA log buffer state */
309                 setup_ima_state(image, params, params_load_addr,
310                                 setup_data_offset);
311                 setup_data_offset += sizeof(struct setup_data) +
312                                      sizeof(struct ima_setup_data);
313         }
314
315         /* Setup RNG seed */
316         setup_rng_seed(params, params_load_addr, setup_data_offset);
317
318         /* Setup EDD info */
319         memcpy(params->eddbuf, boot_params.eddbuf,
320                                 EDDMAXNR * sizeof(struct edd_info));
321         params->eddbuf_entries = boot_params.eddbuf_entries;
322
323         memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
324                EDD_MBR_SIG_MAX * sizeof(unsigned int));
325
326         return ret;
327 }
328
329 static int bzImage64_probe(const char *buf, unsigned long len)
330 {
331         int ret = -ENOEXEC;
332         struct setup_header *header;
333
334         /* kernel should be at least two sectors long */
335         if (len < 2 * 512) {
336                 pr_err("File is too short to be a bzImage\n");
337                 return ret;
338         }
339
340         header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
341         if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
342                 pr_err("Not a bzImage\n");
343                 return ret;
344         }
345
346         if (header->boot_flag != 0xAA55) {
347                 pr_err("No x86 boot sector present\n");
348                 return ret;
349         }
350
351         if (header->version < 0x020C) {
352                 pr_err("Must be at least protocol version 2.12\n");
353                 return ret;
354         }
355
356         if (!(header->loadflags & LOADED_HIGH)) {
357                 pr_err("zImage not a bzImage\n");
358                 return ret;
359         }
360
361         if (!(header->xloadflags & XLF_KERNEL_64)) {
362                 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
363                 return ret;
364         }
365
366         if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
367                 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
368                 return ret;
369         }
370
371         /*
372          * Can't handle 32bit EFI as it does not allow loading kernel
373          * above 4G. This should be handled by 32bit bzImage loader
374          */
375         if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
376                 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
377                 return ret;
378         }
379
380         if (!(header->xloadflags & XLF_5LEVEL) && pgtable_l5_enabled()) {
381                 pr_err("bzImage cannot handle 5-level paging mode.\n");
382                 return ret;
383         }
384
385         /* I've got a bzImage */
386         pr_debug("It's a relocatable bzImage64\n");
387         ret = 0;
388
389         return ret;
390 }
391
392 static void *bzImage64_load(struct kimage *image, char *kernel,
393                             unsigned long kernel_len, char *initrd,
394                             unsigned long initrd_len, char *cmdline,
395                             unsigned long cmdline_len)
396 {
397
398         struct setup_header *header;
399         int setup_sects, kern16_size, ret = 0;
400         unsigned long setup_header_size, params_cmdline_sz;
401         struct boot_params *params;
402         unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
403         struct bzimage64_data *ldata;
404         struct kexec_entry64_regs regs64;
405         void *stack;
406         unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
407         unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
408         struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
409                                   .top_down = true };
410         struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR,
411                                   .buf_max = ULONG_MAX, .top_down = true };
412
413         header = (struct setup_header *)(kernel + setup_hdr_offset);
414         setup_sects = header->setup_sects;
415         if (setup_sects == 0)
416                 setup_sects = 4;
417
418         kern16_size = (setup_sects + 1) * 512;
419         if (kernel_len < kern16_size) {
420                 pr_err("bzImage truncated\n");
421                 return ERR_PTR(-ENOEXEC);
422         }
423
424         if (cmdline_len > header->cmdline_size) {
425                 pr_err("Kernel command line too long\n");
426                 return ERR_PTR(-EINVAL);
427         }
428
429         /*
430          * In case of crash dump, we will append elfcorehdr=<addr> to
431          * command line. Make sure it does not overflow
432          */
433         if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
434                 pr_err("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
435                 return ERR_PTR(-EINVAL);
436         }
437
438 #ifdef CONFIG_CRASH_DUMP
439         /* Allocate and load backup region */
440         if (image->type == KEXEC_TYPE_CRASH) {
441                 ret = crash_load_segments(image);
442                 if (ret)
443                         return ERR_PTR(ret);
444         }
445 #endif
446
447         /*
448          * Load purgatory. For 64bit entry point, purgatory  code can be
449          * anywhere.
450          */
451         ret = kexec_load_purgatory(image, &pbuf);
452         if (ret) {
453                 pr_err("Loading purgatory failed\n");
454                 return ERR_PTR(ret);
455         }
456
457         kexec_dprintk("Loaded purgatory at 0x%lx\n", pbuf.mem);
458
459
460         /*
461          * Load Bootparams and cmdline and space for efi stuff.
462          *
463          * Allocate memory together for multiple data structures so
464          * that they all can go in single area/segment and we don't
465          * have to create separate segment for each. Keeps things
466          * little bit simple
467          */
468         efi_map_sz = efi_get_runtime_map_size();
469         params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
470                                 MAX_ELFCOREHDR_STR_LEN;
471         params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
472         kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
473                                 sizeof(struct setup_data) +
474                                 sizeof(struct efi_setup_data) +
475                                 sizeof(struct setup_data) +
476                                 RNG_SEED_LENGTH;
477
478         if (IS_ENABLED(CONFIG_IMA_KEXEC))
479                 kbuf.bufsz += sizeof(struct setup_data) +
480                               sizeof(struct ima_setup_data);
481
482         params = kzalloc(kbuf.bufsz, GFP_KERNEL);
483         if (!params)
484                 return ERR_PTR(-ENOMEM);
485         efi_map_offset = params_cmdline_sz;
486         efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);
487
488         /* Copy setup header onto bootparams. Documentation/arch/x86/boot.rst */
489         setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
490
491         /* Is there a limit on setup header size? */
492         memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);
493
494         kbuf.buffer = params;
495         kbuf.memsz = kbuf.bufsz;
496         kbuf.buf_align = 16;
497         kbuf.buf_min = MIN_BOOTPARAM_ADDR;
498         ret = kexec_add_buffer(&kbuf);
499         if (ret)
500                 goto out_free_params;
501         bootparam_load_addr = kbuf.mem;
502         kexec_dprintk("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
503                       bootparam_load_addr, kbuf.bufsz, kbuf.memsz);
504
505         /* Load kernel */
506         kbuf.buffer = kernel + kern16_size;
507         kbuf.bufsz =  kernel_len - kern16_size;
508         kbuf.memsz = PAGE_ALIGN(header->init_size);
509         kbuf.buf_align = header->kernel_alignment;
510         if (header->pref_address < MIN_KERNEL_LOAD_ADDR)
511                 kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
512         else
513                 kbuf.buf_min = header->pref_address;
514         kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
515         ret = kexec_add_buffer(&kbuf);
516         if (ret)
517                 goto out_free_params;
518         kernel_load_addr = kbuf.mem;
519
520         kexec_dprintk("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
521                       kernel_load_addr, kbuf.bufsz, kbuf.memsz);
522
523         /* Load initrd high */
524         if (initrd) {
525                 kbuf.buffer = initrd;
526                 kbuf.bufsz = kbuf.memsz = initrd_len;
527                 kbuf.buf_align = PAGE_SIZE;
528                 kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
529                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
530                 ret = kexec_add_buffer(&kbuf);
531                 if (ret)
532                         goto out_free_params;
533                 initrd_load_addr = kbuf.mem;
534
535                 kexec_dprintk("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
536                               initrd_load_addr, initrd_len, initrd_len);
537
538                 setup_initrd(params, initrd_load_addr, initrd_len);
539         }
540
541         setup_cmdline(image, params, bootparam_load_addr,
542                       sizeof(struct boot_params), cmdline, cmdline_len);
543
544         /* bootloader info. Do we need a separate ID for kexec kernel loader? */
545         params->hdr.type_of_loader = 0x0D << 4;
546         params->hdr.loadflags = 0;
547
548         /* Setup purgatory regs for entry */
549         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
550                                              sizeof(regs64), 1);
551         if (ret)
552                 goto out_free_params;
553
554         regs64.rbx = 0; /* Bootstrap Processor */
555         regs64.rsi = bootparam_load_addr;
556         regs64.rip = kernel_load_addr + 0x200;
557         stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
558         if (IS_ERR(stack)) {
559                 pr_err("Could not find address of symbol stack_end\n");
560                 ret = -EINVAL;
561                 goto out_free_params;
562         }
563
564         regs64.rsp = (unsigned long)stack;
565         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
566                                              sizeof(regs64), 0);
567         if (ret)
568                 goto out_free_params;
569
570         ret = setup_boot_parameters(image, params, bootparam_load_addr,
571                                     efi_map_offset, efi_map_sz,
572                                     efi_setup_data_offset);
573         if (ret)
574                 goto out_free_params;
575
576         /* Allocate loader specific data */
577         ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
578         if (!ldata) {
579                 ret = -ENOMEM;
580                 goto out_free_params;
581         }
582
583         /*
584          * Store pointer to params so that it could be freed after loading
585          * params segment has been loaded and contents have been copied
586          * somewhere else.
587          */
588         ldata->bootparams_buf = params;
589         return ldata;
590
591 out_free_params:
592         kfree(params);
593         return ERR_PTR(ret);
594 }
595
596 /* This cleanup function is called after various segments have been loaded */
597 static int bzImage64_cleanup(void *loader_data)
598 {
599         struct bzimage64_data *ldata = loader_data;
600
601         if (!ldata)
602                 return 0;
603
604         kfree(ldata->bootparams_buf);
605         ldata->bootparams_buf = NULL;
606
607         return 0;
608 }
609
610 const struct kexec_file_ops kexec_bzImage64_ops = {
611         .probe = bzImage64_probe,
612         .load = bzImage64_load,
613         .cleanup = bzImage64_cleanup,
614 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
615         .verify_sig = kexec_kernel_verify_pe_sig,
616 #endif
617 };