Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorri...
[sfrench/cifs-2.6.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, &boot_params.screen_info,
215                                 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         /* Always fill in RSDP: it is either 0 or a valid value */
222         params->acpi_rsdp_addr = boot_params.acpi_rsdp_addr;
223
224         /* Default APM info */
225         memset(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));
226
227         /* Default drive info */
228         memset(&params->hd0_info, 0, sizeof(params->hd0_info));
229         memset(&params->hd1_info, 0, sizeof(params->hd1_info));
230
231         if (image->type == KEXEC_TYPE_CRASH) {
232                 ret = crash_setup_memmap_entries(image, params);
233                 if (ret)
234                         return ret;
235         } else
236                 setup_e820_entries(params);
237
238         nr_e820_entries = params->e820_entries;
239
240         for (i = 0; i < nr_e820_entries; i++) {
241                 if (params->e820_table[i].type != E820_TYPE_RAM)
242                         continue;
243                 start = params->e820_table[i].addr;
244                 end = params->e820_table[i].addr + params->e820_table[i].size - 1;
245
246                 if ((start <= 0x100000) && end > 0x100000) {
247                         mem_k = (end >> 10) - (0x100000 >> 10);
248                         params->screen_info.ext_mem_k = mem_k;
249                         params->alt_mem_k = mem_k;
250                         if (mem_k > 0xfc00)
251                                 params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
252                         if (mem_k > 0xffffffff)
253                                 params->alt_mem_k = 0xffffffff;
254                 }
255         }
256
257 #ifdef CONFIG_EFI
258         /* Setup EFI state */
259         setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
260                         efi_setup_data_offset);
261 #endif
262         /* Setup EDD info */
263         memcpy(params->eddbuf, boot_params.eddbuf,
264                                 EDDMAXNR * sizeof(struct edd_info));
265         params->eddbuf_entries = boot_params.eddbuf_entries;
266
267         memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
268                EDD_MBR_SIG_MAX * sizeof(unsigned int));
269
270         return ret;
271 }
272
273 static int bzImage64_probe(const char *buf, unsigned long len)
274 {
275         int ret = -ENOEXEC;
276         struct setup_header *header;
277
278         /* kernel should be at least two sectors long */
279         if (len < 2 * 512) {
280                 pr_err("File is too short to be a bzImage\n");
281                 return ret;
282         }
283
284         header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
285         if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
286                 pr_err("Not a bzImage\n");
287                 return ret;
288         }
289
290         if (header->boot_flag != 0xAA55) {
291                 pr_err("No x86 boot sector present\n");
292                 return ret;
293         }
294
295         if (header->version < 0x020C) {
296                 pr_err("Must be at least protocol version 2.12\n");
297                 return ret;
298         }
299
300         if (!(header->loadflags & LOADED_HIGH)) {
301                 pr_err("zImage not a bzImage\n");
302                 return ret;
303         }
304
305         if (!(header->xloadflags & XLF_KERNEL_64)) {
306                 pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
307                 return ret;
308         }
309
310         if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
311                 pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
312                 return ret;
313         }
314
315         /*
316          * Can't handle 32bit EFI as it does not allow loading kernel
317          * above 4G. This should be handled by 32bit bzImage loader
318          */
319         if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
320                 pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
321                 return ret;
322         }
323
324         /* I've got a bzImage */
325         pr_debug("It's a relocatable bzImage64\n");
326         ret = 0;
327
328         return ret;
329 }
330
331 static void *bzImage64_load(struct kimage *image, char *kernel,
332                             unsigned long kernel_len, char *initrd,
333                             unsigned long initrd_len, char *cmdline,
334                             unsigned long cmdline_len)
335 {
336
337         struct setup_header *header;
338         int setup_sects, kern16_size, ret = 0;
339         unsigned long setup_header_size, params_cmdline_sz;
340         struct boot_params *params;
341         unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
342         struct bzimage64_data *ldata;
343         struct kexec_entry64_regs regs64;
344         void *stack;
345         unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
346         unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
347         struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
348                                   .top_down = true };
349         struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR,
350                                   .buf_max = ULONG_MAX, .top_down = true };
351
352         header = (struct setup_header *)(kernel + setup_hdr_offset);
353         setup_sects = header->setup_sects;
354         if (setup_sects == 0)
355                 setup_sects = 4;
356
357         kern16_size = (setup_sects + 1) * 512;
358         if (kernel_len < kern16_size) {
359                 pr_err("bzImage truncated\n");
360                 return ERR_PTR(-ENOEXEC);
361         }
362
363         if (cmdline_len > header->cmdline_size) {
364                 pr_err("Kernel command line too long\n");
365                 return ERR_PTR(-EINVAL);
366         }
367
368         /*
369          * In case of crash dump, we will append elfcorehdr=<addr> to
370          * command line. Make sure it does not overflow
371          */
372         if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
373                 pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
374                 return ERR_PTR(-EINVAL);
375         }
376
377         /* Allocate and load backup region */
378         if (image->type == KEXEC_TYPE_CRASH) {
379                 ret = crash_load_segments(image);
380                 if (ret)
381                         return ERR_PTR(ret);
382         }
383
384         /*
385          * Load purgatory. For 64bit entry point, purgatory  code can be
386          * anywhere.
387          */
388         ret = kexec_load_purgatory(image, &pbuf);
389         if (ret) {
390                 pr_err("Loading purgatory failed\n");
391                 return ERR_PTR(ret);
392         }
393
394         pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem);
395
396
397         /*
398          * Load Bootparams and cmdline and space for efi stuff.
399          *
400          * Allocate memory together for multiple data structures so
401          * that they all can go in single area/segment and we don't
402          * have to create separate segment for each. Keeps things
403          * little bit simple
404          */
405         efi_map_sz = efi_get_runtime_map_size();
406         params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
407                                 MAX_ELFCOREHDR_STR_LEN;
408         params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
409         kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
410                                 sizeof(struct setup_data) +
411                                 sizeof(struct efi_setup_data);
412
413         params = kzalloc(kbuf.bufsz, GFP_KERNEL);
414         if (!params)
415                 return ERR_PTR(-ENOMEM);
416         efi_map_offset = params_cmdline_sz;
417         efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);
418
419         /* Copy setup header onto bootparams. Documentation/x86/boot.txt */
420         setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;
421
422         /* Is there a limit on setup header size? */
423         memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);
424
425         kbuf.buffer = params;
426         kbuf.memsz = kbuf.bufsz;
427         kbuf.buf_align = 16;
428         kbuf.buf_min = MIN_BOOTPARAM_ADDR;
429         ret = kexec_add_buffer(&kbuf);
430         if (ret)
431                 goto out_free_params;
432         bootparam_load_addr = kbuf.mem;
433         pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
434                  bootparam_load_addr, kbuf.bufsz, kbuf.bufsz);
435
436         /* Load kernel */
437         kbuf.buffer = kernel + kern16_size;
438         kbuf.bufsz =  kernel_len - kern16_size;
439         kbuf.memsz = PAGE_ALIGN(header->init_size);
440         kbuf.buf_align = header->kernel_alignment;
441         kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
442         kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
443         ret = kexec_add_buffer(&kbuf);
444         if (ret)
445                 goto out_free_params;
446         kernel_load_addr = kbuf.mem;
447
448         pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
449                  kernel_load_addr, kbuf.bufsz, kbuf.memsz);
450
451         /* Load initrd high */
452         if (initrd) {
453                 kbuf.buffer = initrd;
454                 kbuf.bufsz = kbuf.memsz = initrd_len;
455                 kbuf.buf_align = PAGE_SIZE;
456                 kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
457                 kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
458                 ret = kexec_add_buffer(&kbuf);
459                 if (ret)
460                         goto out_free_params;
461                 initrd_load_addr = kbuf.mem;
462
463                 pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
464                                 initrd_load_addr, initrd_len, initrd_len);
465
466                 setup_initrd(params, initrd_load_addr, initrd_len);
467         }
468
469         setup_cmdline(image, params, bootparam_load_addr,
470                       sizeof(struct boot_params), cmdline, cmdline_len);
471
472         /* bootloader info. Do we need a separate ID for kexec kernel loader? */
473         params->hdr.type_of_loader = 0x0D << 4;
474         params->hdr.loadflags = 0;
475
476         /* Setup purgatory regs for entry */
477         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
478                                              sizeof(regs64), 1);
479         if (ret)
480                 goto out_free_params;
481
482         regs64.rbx = 0; /* Bootstrap Processor */
483         regs64.rsi = bootparam_load_addr;
484         regs64.rip = kernel_load_addr + 0x200;
485         stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
486         if (IS_ERR(stack)) {
487                 pr_err("Could not find address of symbol stack_end\n");
488                 ret = -EINVAL;
489                 goto out_free_params;
490         }
491
492         regs64.rsp = (unsigned long)stack;
493         ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
494                                              sizeof(regs64), 0);
495         if (ret)
496                 goto out_free_params;
497
498         ret = setup_boot_parameters(image, params, bootparam_load_addr,
499                                     efi_map_offset, efi_map_sz,
500                                     efi_setup_data_offset);
501         if (ret)
502                 goto out_free_params;
503
504         /* Allocate loader specific data */
505         ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
506         if (!ldata) {
507                 ret = -ENOMEM;
508                 goto out_free_params;
509         }
510
511         /*
512          * Store pointer to params so that it could be freed after loading
513          * params segment has been loaded and contents have been copied
514          * somewhere else.
515          */
516         ldata->bootparams_buf = params;
517         return ldata;
518
519 out_free_params:
520         kfree(params);
521         return ERR_PTR(ret);
522 }
523
524 /* This cleanup function is called after various segments have been loaded */
525 static int bzImage64_cleanup(void *loader_data)
526 {
527         struct bzimage64_data *ldata = loader_data;
528
529         if (!ldata)
530                 return 0;
531
532         kfree(ldata->bootparams_buf);
533         ldata->bootparams_buf = NULL;
534
535         return 0;
536 }
537
538 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
539 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
540 {
541         int ret;
542
543         ret = verify_pefile_signature(kernel, kernel_len,
544                                       VERIFY_USE_SECONDARY_KEYRING,
545                                       VERIFYING_KEXEC_PE_SIGNATURE);
546         if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
547                 ret = verify_pefile_signature(kernel, kernel_len,
548                                               VERIFY_USE_PLATFORM_KEYRING,
549                                               VERIFYING_KEXEC_PE_SIGNATURE);
550         }
551         return ret;
552 }
553 #endif
554
555 const struct kexec_file_ops kexec_bzImage64_ops = {
556         .probe = bzImage64_probe,
557         .load = bzImage64_load,
558         .cleanup = bzImage64_cleanup,
559 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
560         .verify_sig = bzImage64_verify_sig,
561 #endif
562 };