GNU Linux-libre 4.4.299-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/verify_pefile.h>
23 #include <keys/system_keyring.h>
24
25 #include <asm/bootparam.h>
26 #include <asm/setup.h>
27 #include <asm/crash.h>
28 #include <asm/efi.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_saved.nr_map;
104
105         /* TODO: Pass entries more than E820MAX in bootparams setup data */
106         if (nr_e820_entries > E820MAX)
107                 nr_e820_entries = E820MAX;
108
109         params->e820_entries = nr_e820_entries;
110         memcpy(&params->e820_map, &e820_saved.map,
111                nr_e820_entries * sizeof(struct e820entry));
112
113         return 0;
114 }
115
116 #ifdef CONFIG_EFI
117 static int setup_efi_info_memmap(struct boot_params *params,
118                                   unsigned long params_load_addr,
119                                   unsigned int efi_map_offset,
120                                   unsigned int efi_map_sz)
121 {
122         void *efi_map = (void *)params + efi_map_offset;
123         unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
124         struct efi_info *ei = &params->efi_info;
125
126         if (!efi_map_sz)
127                 return 0;
128
129         efi_runtime_map_copy(efi_map, efi_map_sz);
130
131         ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
132         ei->efi_memmap_hi = efi_map_phys_addr >> 32;
133         ei->efi_memmap_size = efi_map_sz;
134
135         return 0;
136 }
137
138 static int
139 prepare_add_efi_setup_data(struct boot_params *params,
140                        unsigned long params_load_addr,
141                        unsigned int efi_setup_data_offset)
142 {
143         unsigned long setup_data_phys;
144         struct setup_data *sd = (void *)params + efi_setup_data_offset;
145         struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);
146
147         esd->fw_vendor = efi.fw_vendor;
148         esd->runtime = efi.runtime;
149         esd->tables = efi.config_table;
150         esd->smbios = efi.smbios;
151
152         sd->type = SETUP_EFI;
153         sd->len = sizeof(struct efi_setup_data);
154
155         /* Add setup data */
156         setup_data_phys = params_load_addr + efi_setup_data_offset;
157         sd->next = params->hdr.setup_data;
158         params->hdr.setup_data = setup_data_phys;
159
160         return 0;
161 }
162
163 static int
164 setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
165                 unsigned int efi_map_offset, unsigned int efi_map_sz,
166                 unsigned int efi_setup_data_offset)
167 {
168         struct efi_info *current_ei = &boot_params.efi_info;
169         struct efi_info *ei = &params->efi_info;
170
171         if (!efi_enabled(EFI_RUNTIME_SERVICES))
172                 return 0;
173
174         if (!current_ei->efi_memmap_size)
175                 return 0;
176
177         /*
178          * If 1:1 mapping is not enabled, second kernel can not setup EFI
179          * and use EFI run time services. User space will have to pass
180          * acpi_rsdp=<addr> on kernel command line to make second kernel boot
181          * without efi.
182          */
183         if (efi_enabled(EFI_OLD_MEMMAP))
184                 return 0;
185
186         ei->efi_loader_signature = current_ei->efi_loader_signature;
187         ei->efi_systab = current_ei->efi_systab;
188         ei->efi_systab_hi = current_ei->efi_systab_hi;
189
190         ei->efi_memdesc_version = current_ei->efi_memdesc_version;
191         ei->efi_memdesc_size = efi_get_runtime_map_desc_size();
192
193         setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
194                               efi_map_sz);
195         prepare_add_efi_setup_data(params, params_load_addr,
196                                    efi_setup_data_offset);
197         return 0;
198 }
199 #endif /* CONFIG_EFI */
200
201 static int
202 setup_boot_parameters(struct kimage *image, struct boot_params *params,
203                       unsigned long params_load_addr,
204                       unsigned int efi_map_offset, unsigned int efi_map_sz,
205                       unsigned int efi_setup_data_offset)
206 {
207         unsigned int nr_e820_entries;
208         unsigned long long mem_k, start, end;
209         int i, ret = 0;
210
211         /* Get subarch from existing bootparams */
212         params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;
213
214         /* Copying screen_info will do? */
215         memcpy(&params->screen_info, &screen_info, sizeof(struct screen_info));
216
217         /* Fill in memsize later */
218         params->screen_info.ext_mem_k = 0;
219         params->alt_mem_k = 0;
220
221         /* Default APM info */
222         memset(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));
223
224         /* Default drive info */
225         memset(&params->hd0_info, 0, sizeof(params->hd0_info));
226         memset(&params->hd1_info, 0, sizeof(params->hd1_info));
227
228         if (image->type == KEXEC_TYPE_CRASH) {
229                 ret = crash_setup_memmap_entries(image, params);
230                 if (ret)
231                         return ret;
232         } else
233                 setup_e820_entries(params);
234
235         nr_e820_entries = params->e820_entries;
236
237         for (i = 0; i < nr_e820_entries; i++) {
238                 if (params->e820_map[i].type != E820_RAM)
239                         continue;
240                 start = params->e820_map[i].addr;
241                 end = params->e820_map[i].addr + params->e820_map[i].size - 1;
242
243                 if ((start <= 0x100000) && end > 0x100000) {
244                         mem_k = (end >> 10) - (0x100000 >> 10);
245                         params->screen_info.ext_mem_k = mem_k;
246                         params->alt_mem_k = mem_k;
247                         if (mem_k > 0xfc00)
248                                 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
249                         if (mem_k > 0xffffffff)
250                                 params->alt_mem_k = 0xffffffff;
251                 }
252         }
253
254 #ifdef CONFIG_EFI
255         /* Setup EFI state */
256         setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
257                         efi_setup_data_offset);
258 #endif
259
260         /* Setup EDD info */
261         memcpy(params->eddbuf, boot_params.eddbuf,
262                                 EDDMAXNR * sizeof(struct edd_info));
263         params->eddbuf_entries = boot_params.eddbuf_entries;
264
265         memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
266                EDD_MBR_SIG_MAX * sizeof(unsigned int));
267
268         return ret;
269 }
270
271 static int bzImage64_probe(const char *buf, unsigned long len)
272 {
273         int ret = -ENOEXEC;
274         struct setup_header *header;
275
276         /* kernel should be atleast two sectors long */
277         if (len < 2 * 512) {
278                 pr_err("File is too short to be a bzImage\n");
279                 return ret;
280         }
281
282         header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
283         if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
284                 pr_err("Not a bzImage\n");
285                 return ret;
286         }
287
288         if (header->boot_flag != 0xAA55) {
289                 pr_err("No x86 boot sector present\n");
290                 return ret;
291         }
292
293         if (header->version < 0x020C) {
294                 pr_err("Must be at least protocol version 2.12\n");
295                 return ret;
296         }
297
298         if (!(header->loadflags & LOADED_HIGH)) {
299                 pr_err("zImage not a bzImage\n");
300                 return ret;
301         }
302
303         if (!(header->xloadflags & XLF_KERNEL_64)) {
304                 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
305                 return ret;
306         }
307
308         if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
309                 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
310                 return ret;
311         }
312
313         /*
314          * Can't handle 32bit EFI as it does not allow loading kernel
315          * above 4G. This should be handled by 32bit bzImage loader
316          */
317         if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
318                 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
319                 return ret;
320         }
321
322         /* I've got a bzImage */
323         pr_debug("It's a relocatable bzImage64\n");
324         ret = 0;
325
326         return ret;
327 }
328
329 static void *bzImage64_load(struct kimage *image, char *kernel,
330                             unsigned long kernel_len, char *initrd,
331                             unsigned long initrd_len, char *cmdline,
332                             unsigned long cmdline_len)
333 {
334
335         struct setup_header *header;
336         int setup_sects, kern16_size, ret = 0;
337         unsigned long setup_header_size, params_cmdline_sz, params_misc_sz;
338         struct boot_params *params;
339         unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
340         unsigned long purgatory_load_addr;
341         unsigned long kernel_bufsz, kernel_memsz, kernel_align;
342         char *kernel_buf;
343         struct bzimage64_data *ldata;
344         struct kexec_entry64_regs regs64;
345         void *stack;
346         unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
347         unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
348
349         header = (struct setup_header *)(kernel + setup_hdr_offset);
350         setup_sects = header->setup_sects;
351         if (setup_sects == 0)
352                 setup_sects = 4;
353
354         kern16_size = (setup_sects + 1) * 512;
355         if (kernel_len < kern16_size) {
356                 pr_err("bzImage truncated\n");
357                 return ERR_PTR(-ENOEXEC);
358         }
359
360         if (cmdline_len > header->cmdline_size) {
361                 pr_err("Kernel command line too long\n");
362                 return ERR_PTR(-EINVAL);
363         }
364
365         /*
366          * In case of crash dump, we will append elfcorehdr=<addr> to
367          * command line. Make sure it does not overflow
368          */
369         if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
370                 pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
371                 return ERR_PTR(-EINVAL);
372         }
373
374         /* Allocate and load backup region */
375         if (image->type == KEXEC_TYPE_CRASH) {
376                 ret = crash_load_segments(image);
377                 if (ret)
378                         return ERR_PTR(ret);
379         }
380
381         /*
382          * Load purgatory. For 64bit entry point, purgatory  code can be
383          * anywhere.
384          */
385         ret = kexec_load_purgatory(image, MIN_PURGATORY_ADDR, ULONG_MAX, 1,
386                                    &purgatory_load_addr);
387         if (ret) {
388                 pr_err("Loading purgatory failed\n");
389                 return ERR_PTR(ret);
390         }
391
392         pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
393
394
395         /*
396          * Load Bootparams and cmdline and space for efi stuff.
397          *
398          * Allocate memory together for multiple data structures so
399          * that they all can go in single area/segment and we don't
400          * have to create separate segment for each. Keeps things
401          * little bit simple
402          */
403         efi_map_sz = efi_get_runtime_map_size();
404         efi_map_sz = ALIGN(efi_map_sz, 16);
405         params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
406                                 MAX_ELFCOREHDR_STR_LEN;
407         params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
408         params_misc_sz = params_cmdline_sz + efi_map_sz +
409                                 sizeof(struct setup_data) +
410                                 sizeof(struct efi_setup_data);
411
412         params = kzalloc(params_misc_sz, GFP_KERNEL);
413         if (!params)
414                 return ERR_PTR(-ENOMEM);
415         efi_map_offset = params_cmdline_sz;
416         efi_setup_data_offset = efi_map_offset + efi_map_sz;
417
418         /* Copy setup header onto bootparams. Documentation/x86/boot.txt */
419         setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
420
421         /* Is there a limit on setup header size? */
422         memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);
423
424         ret = kexec_add_buffer(image, (char *)params, params_misc_sz,
425                                params_misc_sz, 16, MIN_BOOTPARAM_ADDR,
426                                ULONG_MAX, 1, &bootparam_load_addr);
427         if (ret)
428                 goto out_free_params;
429         pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
430                  bootparam_load_addr, params_misc_sz, params_misc_sz);
431
432         /* Load kernel */
433         kernel_buf = kernel + kern16_size;
434         kernel_bufsz =  kernel_len - kern16_size;
435         kernel_memsz = PAGE_ALIGN(header->init_size);
436         kernel_align = header->kernel_alignment;
437
438         ret = kexec_add_buffer(image, kernel_buf,
439                                kernel_bufsz, kernel_memsz, kernel_align,
440                                MIN_KERNEL_LOAD_ADDR, ULONG_MAX, 1,
441                                &kernel_load_addr);
442         if (ret)
443                 goto out_free_params;
444
445         pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
446                  kernel_load_addr, kernel_memsz, kernel_memsz);
447
448         /* Load initrd high */
449         if (initrd) {
450                 ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len,
451                                        PAGE_SIZE, MIN_INITRD_LOAD_ADDR,
452                                        ULONG_MAX, 1, &initrd_load_addr);
453                 if (ret)
454                         goto out_free_params;
455
456                 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
457                                 initrd_load_addr, initrd_len, initrd_len);
458
459                 setup_initrd(params, initrd_load_addr, initrd_len);
460         }
461
462         setup_cmdline(image, params, bootparam_load_addr,
463                       sizeof(struct boot_params), cmdline, cmdline_len);
464
465         /* bootloader info. Do we need a separate ID for kexec kernel loader? */
466         params->hdr.type_of_loader = 0x0D << 4;
467         params->hdr.loadflags = 0;
468
469         /* Setup purgatory regs for entry */
470         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
471                                              sizeof(regs64), 1);
472         if (ret)
473                 goto out_free_params;
474
475         regs64.rbx = 0; /* Bootstrap Processor */
476         regs64.rsi = bootparam_load_addr;
477         regs64.rip = kernel_load_addr + 0x200;
478         stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
479         if (IS_ERR(stack)) {
480                 pr_err("Could not find address of symbol stack_end\n");
481                 ret = -EINVAL;
482                 goto out_free_params;
483         }
484
485         regs64.rsp = (unsigned long)stack;
486         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
487                                              sizeof(regs64), 0);
488         if (ret)
489                 goto out_free_params;
490
491         ret = setup_boot_parameters(image, params, bootparam_load_addr,
492                                     efi_map_offset, efi_map_sz,
493                                     efi_setup_data_offset);
494         if (ret)
495                 goto out_free_params;
496
497         /* Allocate loader specific data */
498         ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
499         if (!ldata) {
500                 ret = -ENOMEM;
501                 goto out_free_params;
502         }
503
504         /*
505          * Store pointer to params so that it could be freed after loading
506          * params segment has been loaded and contents have been copied
507          * somewhere else.
508          */
509         ldata->bootparams_buf = params;
510         return ldata;
511
512 out_free_params:
513         kfree(params);
514         return ERR_PTR(ret);
515 }
516
517 /* This cleanup function is called after various segments have been loaded */
518 static int bzImage64_cleanup(void *loader_data)
519 {
520         struct bzimage64_data *ldata = loader_data;
521
522         if (!ldata)
523                 return 0;
524
525         kfree(ldata->bootparams_buf);
526         ldata->bootparams_buf = NULL;
527
528         return 0;
529 }
530
531 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
532 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
533 {
534         bool trusted;
535         int ret;
536
537         ret = verify_pefile_signature(kernel, kernel_len,
538                                       system_trusted_keyring,
539                                       VERIFYING_KEXEC_PE_SIGNATURE,
540                                       &trusted);
541         if (ret < 0)
542                 return ret;
543         if (!trusted)
544                 return -EKEYREJECTED;
545         return 0;
546 }
547 #endif
548
549 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 };