kexec-bzimage64.c 15 KB

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