GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / kernel / kexec-bzimage64.c
1 /*
2  * Kexec bzImage loader
3  *
4  * Copyright (C) 2014 Red Hat Inc.
5  * Authors:
6  *      Vivek Goyal <vgoyal@redhat.com>
7  *
8  * This source code is licensed under the GNU General Public License,
9  * Version 2.  See the file COPYING for more details.
10  */
11
12 #define pr_fmt(fmt)     "kexec-bzImage64: " fmt
13
14 #include <linux/string.h>
15 #include <linux/printk.h>
16 #include <linux/errno.h>
17 #include <linux/slab.h>
18 #include <linux/kexec.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/efi.h>
22 #include <linux/verification.h>
23
24 #include <asm/bootparam.h>
25 #include <asm/setup.h>
26 #include <asm/crash.h>
27 #include <asm/efi.h>
28 #include <asm/e820/api.h>
29 #include <asm/kexec-bzimage64.h>
30
31 #define MAX_ELFCOREHDR_STR_LEN  30      /* elfcorehdr=0x<64bit-value> */
32
33 /*
34  * Defines lowest physical address for various segments. Not sure where
35  * exactly these limits came from. Current bzimage64 loader in kexec-tools
36  * uses these so I am retaining it. It can be changed over time as we gain
37  * more insight.
38  */
39 #define MIN_PURGATORY_ADDR      0x3000
40 #define MIN_BOOTPARAM_ADDR      0x3000
41 #define MIN_KERNEL_LOAD_ADDR    0x100000
42 #define MIN_INITRD_LOAD_ADDR    0x1000000
43
44 /*
45  * This is a place holder for all boot loader specific data structure which
46  * gets allocated in one call but gets freed much later during cleanup
47  * time. Right now there is only one field but it can grow as need be.
48  */
49 struct bzimage64_data {
50         /*
51          * Temporary buffer to hold bootparams buffer. This should be
52          * freed once the bootparam segment has been loaded.
53          */
54         void *bootparams_buf;
55 };
56
57 static int setup_initrd(struct boot_params *params,
58                 unsigned long initrd_load_addr, unsigned long initrd_len)
59 {
60         params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL;
61         params->hdr.ramdisk_size = initrd_len & 0xffffffffUL;
62
63         params->ext_ramdisk_image = initrd_load_addr >> 32;
64         params->ext_ramdisk_size = initrd_len >> 32;
65
66         return 0;
67 }
68
69 static int setup_cmdline(struct kimage *image, struct boot_params *params,
70                          unsigned long bootparams_load_addr,
71                          unsigned long cmdline_offset, char *cmdline,
72                          unsigned long cmdline_len)
73 {
74         char *cmdline_ptr = ((char *)params) + cmdline_offset;
75         unsigned long cmdline_ptr_phys, len = 0;
76         uint32_t cmdline_low_32, cmdline_ext_32;
77
78         if (image->type == KEXEC_TYPE_CRASH) {
79                 len = sprintf(cmdline_ptr,
80                         "elfcorehdr=0x%lx ", image->arch.elf_load_addr);
81         }
82         memcpy(cmdline_ptr + len, cmdline, cmdline_len);
83         cmdline_len += len;
84
85         cmdline_ptr[cmdline_len - 1] = '\0';
86
87         pr_debug("Final command line is: %s\n", cmdline_ptr);
88         cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
89         cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
90         cmdline_ext_32 = cmdline_ptr_phys >> 32;
91
92         params->hdr.cmd_line_ptr = cmdline_low_32;
93         if (cmdline_ext_32)
94                 params->ext_cmd_line_ptr = cmdline_ext_32;
95
96         return 0;
97 }
98
99 static int setup_e820_entries(struct boot_params *params)
100 {
101         unsigned int nr_e820_entries;
102
103         nr_e820_entries = e820_table_kexec->nr_entries;
104
105         /* TODO: Pass entries more than E820_MAX_ENTRIES_ZEROPAGE in bootparams setup data */
106         if (nr_e820_entries > E820_MAX_ENTRIES_ZEROPAGE)
107                 nr_e820_entries = E820_MAX_ENTRIES_ZEROPAGE;
108
109         params->e820_entries = nr_e820_entries;
110         memcpy(&params->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry));
111
112         return 0;
113 }
114
115 #ifdef CONFIG_EFI
116 static int setup_efi_info_memmap(struct boot_params *params,
117                                   unsigned long params_load_addr,
118                                   unsigned int efi_map_offset,
119                                   unsigned int efi_map_sz)
120 {
121         void *efi_map = (void *)params + efi_map_offset;
122         unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
123         struct efi_info *ei = &params->efi_info;
124
125         if (!efi_map_sz)
126                 return 0;
127
128         efi_runtime_map_copy(efi_map, efi_map_sz);
129
130         ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
131         ei->efi_memmap_hi = efi_map_phys_addr >> 32;
132         ei->efi_memmap_size = efi_map_sz;
133
134         return 0;
135 }
136
137 static int
138 prepare_add_efi_setup_data(struct boot_params *params,
139                        unsigned long params_load_addr,
140                        unsigned int efi_setup_data_offset)
141 {
142         unsigned long setup_data_phys;
143         struct setup_data *sd = (void *)params + efi_setup_data_offset;
144         struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
145
146         esd->fw_vendor = efi.fw_vendor;
147         esd->runtime = efi.runtime;
148         esd->tables = efi.config_table;
149         esd->smbios = efi.smbios;
150
151         sd->type = SETUP_EFI;
152         sd->len = sizeof(struct efi_setup_data);
153
154         /* Add setup data */
155         setup_data_phys = params_load_addr + efi_setup_data_offset;
156         sd->next = params->hdr.setup_data;
157         params->hdr.setup_data = setup_data_phys;
158
159         return 0;
160 }
161
162 static int
163 setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
164                 unsigned int efi_map_offset, unsigned int efi_map_sz,
165                 unsigned int efi_setup_data_offset)
166 {
167         struct efi_info *current_ei = &boot_params.efi_info;
168         struct efi_info *ei = &params->efi_info;
169
170         if (!efi_enabled(EFI_RUNTIME_SERVICES))
171                 return 0;
172
173         if (!current_ei->efi_memmap_size)
174                 return 0;
175
176         /*
177          * If 1:1 mapping is not enabled, second kernel can not setup EFI
178          * and use EFI run time services. User space will have to pass
179          * acpi_rsdp=<addr> on kernel command line to make second kernel boot
180          * without efi.
181          */
182         if (efi_enabled(EFI_OLD_MEMMAP))
183                 return 0;
184
185         ei->efi_loader_signature = current_ei->efi_loader_signature;
186         ei->efi_systab = current_ei->efi_systab;
187         ei->efi_systab_hi = current_ei->efi_systab_hi;
188
189         ei->efi_memdesc_version = current_ei->efi_memdesc_version;
190         ei->efi_memdesc_size = efi_get_runtime_map_desc_size();
191
192         setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
193                               efi_map_sz);
194         prepare_add_efi_setup_data(params, params_load_addr,
195                                    efi_setup_data_offset);
196         return 0;
197 }
198 #endif /* CONFIG_EFI */
199
200 static int
201 setup_boot_parameters(struct kimage *image, struct boot_params *params,
202                       unsigned long params_load_addr,
203                       unsigned int efi_map_offset, unsigned int efi_map_sz,
204                       unsigned int efi_setup_data_offset)
205 {
206         unsigned int nr_e820_entries;
207         unsigned long long mem_k, start, end;
208         int i, ret = 0;
209
210         /* Get subarch from existing bootparams */
211         params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
212
213         /* Copying screen_info will do? */
214         memcpy(&params->screen_info, &screen_info, sizeof(struct screen_info));
215
216         /* Fill in memsize later */
217         params->screen_info.ext_mem_k = 0;
218         params->alt_mem_k = 0;
219
220         /* Default APM info */
221         memset(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));
222
223         /* Default drive info */
224         memset(&params->hd0_info, 0, sizeof(params->hd0_info));
225         memset(&params->hd1_info, 0, sizeof(params->hd1_info));
226
227         if (image->type == KEXEC_TYPE_CRASH) {
228                 ret = crash_setup_memmap_entries(image, params);
229                 if (ret)
230                         return ret;
231         } else
232                 setup_e820_entries(params);
233
234         nr_e820_entries = params->e820_entries;
235
236         for (i = 0; i < nr_e820_entries; i++) {
237                 if (params->e820_table[i].type != E820_TYPE_RAM)
238                         continue;
239                 start = params->e820_table[i].addr;
240                 end = params->e820_table[i].addr + params->e820_table[i].size - 1;
241
242                 if ((start <= 0x100000) && end > 0x100000) {
243                         mem_k = (end >> 10) - (0x100000 >> 10);
244                         params->screen_info.ext_mem_k = mem_k;
245                         params->alt_mem_k = mem_k;
246                         if (mem_k > 0xfc00)
247                                 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
248                         if (mem_k > 0xffffffff)
249                                 params->alt_mem_k = 0xffffffff;
250                 }
251         }
252
253 #ifdef CONFIG_EFI
254         /* Setup EFI state */
255         setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
256                         efi_setup_data_offset);
257 #endif
258
259         /* Setup EDD info */
260         memcpy(params->eddbuf, boot_params.eddbuf,
261                                 EDDMAXNR * sizeof(struct edd_info));
262         params->eddbuf_entries = boot_params.eddbuf_entries;
263
264         memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
265                EDD_MBR_SIG_MAX * sizeof(unsigned int));
266
267         return ret;
268 }
269
270 static int bzImage64_probe(const char *buf, unsigned long len)
271 {
272         int ret = -ENOEXEC;
273         struct setup_header *header;
274
275         /* kernel should be at least two sectors long */
276         if (len < 2 * 512) {
277                 pr_err("File is too short to be a bzImage\n");
278                 return ret;
279         }
280
281         header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
282         if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
283                 pr_err("Not a bzImage\n");
284                 return ret;
285         }
286
287         if (header->boot_flag != 0xAA55) {
288                 pr_err("No x86 boot sector present\n");
289                 return ret;
290         }
291
292         if (header->version < 0x020C) {
293                 pr_err("Must be at least protocol version 2.12\n");
294                 return ret;
295         }
296
297         if (!(header->loadflags & LOADED_HIGH)) {
298                 pr_err("zImage not a bzImage\n");
299                 return ret;
300         }
301
302         if (!(header->xloadflags & XLF_KERNEL_64)) {
303                 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
304                 return ret;
305         }
306
307         if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
308                 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
309                 return ret;
310         }
311
312         /*
313          * Can't handle 32bit EFI as it does not allow loading kernel
314          * above 4G. This should be handled by 32bit bzImage loader
315          */
316         if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
317                 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
318                 return ret;
319         }
320
321         /* I've got a bzImage */
322         pr_debug("It's a relocatable bzImage64\n");
323         ret = 0;
324
325         return ret;
326 }
327
328 static void *bzImage64_load(struct kimage *image, char *kernel,
329                             unsigned long kernel_len, char *initrd,
330                             unsigned long initrd_len, char *cmdline,
331                             unsigned long cmdline_len)
332 {
333
334         struct setup_header *header;
335         int setup_sects, kern16_size, ret = 0;
336         unsigned long setup_header_size, params_cmdline_sz;
337         struct boot_params *params;
338         unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
339         unsigned long purgatory_load_addr;
340         struct bzimage64_data *ldata;
341         struct kexec_entry64_regs regs64;
342         void *stack;
343         unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
344         unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
345         struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
346                                   .top_down = true };
347
348         header = (struct setup_header *)(kernel + setup_hdr_offset);
349         setup_sects = header->setup_sects;
350         if (setup_sects == 0)
351                 setup_sects = 4;
352
353         kern16_size = (setup_sects + 1) * 512;
354         if (kernel_len < kern16_size) {
355                 pr_err("bzImage truncated\n");
356                 return ERR_PTR(-ENOEXEC);
357         }
358
359         if (cmdline_len > header->cmdline_size) {
360                 pr_err("Kernel command line too long\n");
361                 return ERR_PTR(-EINVAL);
362         }
363
364         /*
365          * In case of crash dump, we will append elfcorehdr=<addr> to
366          * command line. Make sure it does not overflow
367          */
368         if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
369                 pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
370                 return ERR_PTR(-EINVAL);
371         }
372
373         /* Allocate and load backup region */
374         if (image->type == KEXEC_TYPE_CRASH) {
375                 ret = crash_load_segments(image);
376                 if (ret)
377                         return ERR_PTR(ret);
378         }
379
380         /*
381          * Load purgatory. For 64bit entry point, purgatory  code can be
382          * anywhere.
383          */
384         ret = kexec_load_purgatory(image, MIN_PURGATORY_ADDR, ULONG_MAX, 1,
385                                    &purgatory_load_addr);
386         if (ret) {
387                 pr_err("Loading purgatory failed\n");
388                 return ERR_PTR(ret);
389         }
390
391         pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
392
393
394         /*
395          * Load Bootparams and cmdline and space for efi stuff.
396          *
397          * Allocate memory together for multiple data structures so
398          * that they all can go in single area/segment and we don't
399          * have to create separate segment for each. Keeps things
400          * little bit simple
401          */
402         efi_map_sz = efi_get_runtime_map_size();
403         params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
404                                 MAX_ELFCOREHDR_STR_LEN;
405         params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
406         kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
407                                 sizeof(struct setup_data) +
408                                 sizeof(struct efi_setup_data);
409
410         params = kzalloc(kbuf.bufsz, GFP_KERNEL);
411         if (!params)
412                 return ERR_PTR(-ENOMEM);
413         efi_map_offset = params_cmdline_sz;
414         efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);
415
416         /* Copy setup header onto bootparams. Documentation/x86/boot.txt */
417         setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
418
419         /* Is there a limit on setup header size? */
420         memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);
421
422         kbuf.buffer = params;
423         kbuf.memsz = kbuf.bufsz;
424         kbuf.buf_align = 16;
425         kbuf.buf_min = MIN_BOOTPARAM_ADDR;
426         ret = kexec_add_buffer(&kbuf);
427         if (ret)
428                 goto out_free_params;
429         bootparam_load_addr = kbuf.mem;
430         pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
431                  bootparam_load_addr, kbuf.bufsz, kbuf.bufsz);
432
433         /* Load kernel */
434         kbuf.buffer = kernel + kern16_size;
435         kbuf.bufsz =  kernel_len - kern16_size;
436         kbuf.memsz = PAGE_ALIGN(header->init_size);
437         kbuf.buf_align = header->kernel_alignment;
438         kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
439         ret = kexec_add_buffer(&kbuf);
440         if (ret)
441                 goto out_free_params;
442         kernel_load_addr = kbuf.mem;
443
444         pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
445                  kernel_load_addr, kbuf.bufsz, kbuf.memsz);
446
447         /* Load initrd high */
448         if (initrd) {
449                 kbuf.buffer = initrd;
450                 kbuf.bufsz = kbuf.memsz = initrd_len;
451                 kbuf.buf_align = PAGE_SIZE;
452                 kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
453                 ret = kexec_add_buffer(&kbuf);
454                 if (ret)
455                         goto out_free_params;
456                 initrd_load_addr = kbuf.mem;
457
458                 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
459                                 initrd_load_addr, initrd_len, initrd_len);
460
461                 setup_initrd(params, initrd_load_addr, initrd_len);
462         }
463
464         setup_cmdline(image, params, bootparam_load_addr,
465                       sizeof(struct boot_params), cmdline, cmdline_len);
466
467         /* bootloader info. Do we need a separate ID for kexec kernel loader? */
468         params->hdr.type_of_loader = 0x0D << 4;
469         params->hdr.loadflags = 0;
470
471         /* Setup purgatory regs for entry */
472         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
473                                              sizeof(regs64), 1);
474         if (ret)
475                 goto out_free_params;
476
477         regs64.rbx = 0; /* Bootstrap Processor */
478         regs64.rsi = bootparam_load_addr;
479         regs64.rip = kernel_load_addr + 0x200;
480         stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
481         if (IS_ERR(stack)) {
482                 pr_err("Could not find address of symbol stack_end\n");
483                 ret = -EINVAL;
484                 goto out_free_params;
485         }
486
487         regs64.rsp = (unsigned long)stack;
488         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
489                                              sizeof(regs64), 0);
490         if (ret)
491                 goto out_free_params;
492
493         ret = setup_boot_parameters(image, params, bootparam_load_addr,
494                                     efi_map_offset, efi_map_sz,
495                                     efi_setup_data_offset);
496         if (ret)
497                 goto out_free_params;
498
499         /* Allocate loader specific data */
500         ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
501         if (!ldata) {
502                 ret = -ENOMEM;
503                 goto out_free_params;
504         }
505
506         /*
507          * Store pointer to params so that it could be freed after loading
508          * params segment has been loaded and contents have been copied
509          * somewhere else.
510          */
511         ldata->bootparams_buf = params;
512         return ldata;
513
514 out_free_params:
515         kfree(params);
516         return ERR_PTR(ret);
517 }
518
519 /* This cleanup function is called after various segments have been loaded */
520 static int bzImage64_cleanup(void *loader_data)
521 {
522         struct bzimage64_data *ldata = loader_data;
523
524         if (!ldata)
525                 return 0;
526
527         kfree(ldata->bootparams_buf);
528         ldata->bootparams_buf = NULL;
529
530         return 0;
531 }
532
533 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
534 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
535 {
536         return verify_pefile_signature(kernel, kernel_len,
537                                        VERIFY_USE_SECONDARY_KEYRING,
538                                        VERIFYING_KEXEC_PE_SIGNATURE);
539 }
540 #endif
541
542 struct kexec_file_ops kexec_bzImage64_ops = {
543         .probe = bzImage64_probe,
544         .load = bzImage64_load,
545         .cleanup = bzImage64_cleanup,
546 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
547         .verify_sig = bzImage64_verify_sig,
548 #endif
549 };