Commit | Line | Data |
---|---|---|
5234f5eb | 1 | /* |
835c34a1 | 2 | * handle transition of Linux booting another kernel |
5234f5eb EB |
3 | * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> |
4 | * | |
5 | * This source code is licensed under the GNU General Public License, | |
6 | * Version 2. See the file COPYING for more details. | |
7 | */ | |
8 | ||
12db5562 VG |
9 | #define pr_fmt(fmt) "kexec: " fmt |
10 | ||
5234f5eb EB |
11 | #include <linux/mm.h> |
12 | #include <linux/kexec.h> | |
5234f5eb | 13 | #include <linux/string.h> |
5a0e3ad6 | 14 | #include <linux/gfp.h> |
5234f5eb | 15 | #include <linux/reboot.h> |
fd59d231 | 16 | #include <linux/numa.h> |
f43fdad8 | 17 | #include <linux/ftrace.h> |
fef3a7a1 | 18 | #include <linux/io.h> |
fee7b0d8 | 19 | #include <linux/suspend.h> |
f43fdad8 | 20 | |
9ebdc79f | 21 | #include <asm/init.h> |
5234f5eb | 22 | #include <asm/pgtable.h> |
5234f5eb EB |
23 | #include <asm/tlbflush.h> |
24 | #include <asm/mmu_context.h> | |
17f557e5 | 25 | #include <asm/debugreg.h> |
27f48d3e | 26 | #include <asm/kexec-bzimage64.h> |
8bf27556 | 27 | |
74ca317c | 28 | #ifdef CONFIG_KEXEC_FILE |
cb105258 | 29 | static struct kexec_file_ops *kexec_file_loaders[] = { |
27f48d3e | 30 | &kexec_bzImage64_ops, |
cb105258 | 31 | }; |
74ca317c | 32 | #endif |
cb105258 | 33 | |
f5deb796 HY |
34 | static void free_transition_pgtable(struct kimage *image) |
35 | { | |
36 | free_page((unsigned long)image->arch.pud); | |
37 | free_page((unsigned long)image->arch.pmd); | |
38 | free_page((unsigned long)image->arch.pte); | |
39 | } | |
40 | ||
41 | static int init_transition_pgtable(struct kimage *image, pgd_t *pgd) | |
42 | { | |
43 | pud_t *pud; | |
44 | pmd_t *pmd; | |
45 | pte_t *pte; | |
46 | unsigned long vaddr, paddr; | |
47 | int result = -ENOMEM; | |
48 | ||
49 | vaddr = (unsigned long)relocate_kernel; | |
50 | paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE); | |
51 | pgd += pgd_index(vaddr); | |
52 | if (!pgd_present(*pgd)) { | |
53 | pud = (pud_t *)get_zeroed_page(GFP_KERNEL); | |
54 | if (!pud) | |
55 | goto err; | |
56 | image->arch.pud = pud; | |
57 | set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); | |
58 | } | |
59 | pud = pud_offset(pgd, vaddr); | |
60 | if (!pud_present(*pud)) { | |
61 | pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL); | |
62 | if (!pmd) | |
63 | goto err; | |
64 | image->arch.pmd = pmd; | |
65 | set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); | |
66 | } | |
67 | pmd = pmd_offset(pud, vaddr); | |
68 | if (!pmd_present(*pmd)) { | |
69 | pte = (pte_t *)get_zeroed_page(GFP_KERNEL); | |
70 | if (!pte) | |
71 | goto err; | |
72 | image->arch.pte = pte; | |
73 | set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE)); | |
74 | } | |
75 | pte = pte_offset_kernel(pmd, vaddr); | |
76 | set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC)); | |
77 | return 0; | |
78 | err: | |
79 | free_transition_pgtable(image); | |
80 | return result; | |
81 | } | |
82 | ||
9ebdc79f YL |
83 | static void *alloc_pgt_page(void *data) |
84 | { | |
85 | struct kimage *image = (struct kimage *)data; | |
86 | struct page *page; | |
87 | void *p = NULL; | |
88 | ||
89 | page = kimage_alloc_control_pages(image, 0); | |
90 | if (page) { | |
91 | p = page_address(page); | |
92 | clear_page(p); | |
93 | } | |
94 | ||
95 | return p; | |
96 | } | |
97 | ||
5234f5eb EB |
98 | static int init_pgtable(struct kimage *image, unsigned long start_pgtable) |
99 | { | |
9ebdc79f YL |
100 | struct x86_mapping_info info = { |
101 | .alloc_pgt_page = alloc_pgt_page, | |
102 | .context = image, | |
103 | .pmd_flag = __PAGE_KERNEL_LARGE_EXEC, | |
104 | }; | |
084d1283 | 105 | unsigned long mstart, mend; |
8bf27556 | 106 | pgd_t *level4p; |
f5deb796 | 107 | int result; |
084d1283 YL |
108 | int i; |
109 | ||
8bf27556 | 110 | level4p = (pgd_t *)__va(start_pgtable); |
9ebdc79f | 111 | clear_page(level4p); |
0e691cf8 YL |
112 | for (i = 0; i < nr_pfn_mapped; i++) { |
113 | mstart = pfn_mapped[i].start << PAGE_SHIFT; | |
114 | mend = pfn_mapped[i].end << PAGE_SHIFT; | |
115 | ||
116 | result = kernel_ident_mapping_init(&info, | |
117 | level4p, mstart, mend); | |
118 | if (result) | |
119 | return result; | |
120 | } | |
084d1283 | 121 | |
53594547 | 122 | /* |
084d1283 YL |
123 | * segments's mem ranges could be outside 0 ~ max_pfn, |
124 | * for example when jump back to original kernel from kexeced kernel. | |
125 | * or first kernel is booted with user mem map, and second kernel | |
126 | * could be loaded out of that range. | |
53594547 | 127 | */ |
084d1283 YL |
128 | for (i = 0; i < image->nr_segments; i++) { |
129 | mstart = image->segment[i].mem; | |
130 | mend = mstart + image->segment[i].memsz; | |
131 | ||
9ebdc79f YL |
132 | result = kernel_ident_mapping_init(&info, |
133 | level4p, mstart, mend); | |
084d1283 YL |
134 | |
135 | if (result) | |
136 | return result; | |
137 | } | |
138 | ||
f5deb796 | 139 | return init_transition_pgtable(image, level4p); |
5234f5eb EB |
140 | } |
141 | ||
142 | static void set_idt(void *newidt, u16 limit) | |
143 | { | |
36c4fd23 | 144 | struct desc_ptr curidt; |
5234f5eb EB |
145 | |
146 | /* x86-64 supports unaliged loads & stores */ | |
36c4fd23 EB |
147 | curidt.size = limit; |
148 | curidt.address = (unsigned long)newidt; | |
5234f5eb EB |
149 | |
150 | __asm__ __volatile__ ( | |
36c4fd23 EB |
151 | "lidtq %0\n" |
152 | : : "m" (curidt) | |
5234f5eb EB |
153 | ); |
154 | }; | |
155 | ||
156 | ||
157 | static void set_gdt(void *newgdt, u16 limit) | |
158 | { | |
36c4fd23 | 159 | struct desc_ptr curgdt; |
5234f5eb EB |
160 | |
161 | /* x86-64 supports unaligned loads & stores */ | |
36c4fd23 EB |
162 | curgdt.size = limit; |
163 | curgdt.address = (unsigned long)newgdt; | |
5234f5eb EB |
164 | |
165 | __asm__ __volatile__ ( | |
36c4fd23 EB |
166 | "lgdtq %0\n" |
167 | : : "m" (curgdt) | |
5234f5eb EB |
168 | ); |
169 | }; | |
170 | ||
171 | static void load_segments(void) | |
172 | { | |
173 | __asm__ __volatile__ ( | |
36c4fd23 EB |
174 | "\tmovl %0,%%ds\n" |
175 | "\tmovl %0,%%es\n" | |
176 | "\tmovl %0,%%ss\n" | |
177 | "\tmovl %0,%%fs\n" | |
178 | "\tmovl %0,%%gs\n" | |
2ec5e3a8 | 179 | : : "a" (__KERNEL_DS) : "memory" |
5234f5eb | 180 | ); |
5234f5eb EB |
181 | } |
182 | ||
74ca317c | 183 | #ifdef CONFIG_KEXEC_FILE |
dd5f7260 VG |
184 | /* Update purgatory as needed after various image segments have been prepared */ |
185 | static int arch_update_purgatory(struct kimage *image) | |
186 | { | |
187 | int ret = 0; | |
188 | ||
189 | if (!image->file_mode) | |
190 | return 0; | |
191 | ||
192 | /* Setup copying of backup region */ | |
193 | if (image->type == KEXEC_TYPE_CRASH) { | |
194 | ret = kexec_purgatory_get_set_symbol(image, "backup_dest", | |
195 | &image->arch.backup_load_addr, | |
196 | sizeof(image->arch.backup_load_addr), 0); | |
197 | if (ret) | |
198 | return ret; | |
199 | ||
200 | ret = kexec_purgatory_get_set_symbol(image, "backup_src", | |
201 | &image->arch.backup_src_start, | |
202 | sizeof(image->arch.backup_src_start), 0); | |
203 | if (ret) | |
204 | return ret; | |
205 | ||
206 | ret = kexec_purgatory_get_set_symbol(image, "backup_sz", | |
207 | &image->arch.backup_src_sz, | |
208 | sizeof(image->arch.backup_src_sz), 0); | |
209 | if (ret) | |
210 | return ret; | |
211 | } | |
212 | ||
213 | return ret; | |
214 | } | |
74ca317c VG |
215 | #else /* !CONFIG_KEXEC_FILE */ |
216 | static inline int arch_update_purgatory(struct kimage *image) | |
217 | { | |
218 | return 0; | |
219 | } | |
220 | #endif /* CONFIG_KEXEC_FILE */ | |
dd5f7260 | 221 | |
5234f5eb EB |
222 | int machine_kexec_prepare(struct kimage *image) |
223 | { | |
4bfaaef0 | 224 | unsigned long start_pgtable; |
5234f5eb EB |
225 | int result; |
226 | ||
227 | /* Calculate the offsets */ | |
72414d3f | 228 | start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT; |
5234f5eb EB |
229 | |
230 | /* Setup the identity mapped 64bit page table */ | |
231 | result = init_pgtable(image, start_pgtable); | |
72414d3f | 232 | if (result) |
5234f5eb | 233 | return result; |
5234f5eb | 234 | |
dd5f7260 VG |
235 | /* update purgatory as needed */ |
236 | result = arch_update_purgatory(image); | |
237 | if (result) | |
238 | return result; | |
239 | ||
5234f5eb EB |
240 | return 0; |
241 | } | |
242 | ||
243 | void machine_kexec_cleanup(struct kimage *image) | |
244 | { | |
f5deb796 | 245 | free_transition_pgtable(image); |
5234f5eb EB |
246 | } |
247 | ||
248 | /* | |
249 | * Do not allocate memory (or fail in any way) in machine_kexec(). | |
250 | * We are past the point of no return, committed to rebooting now. | |
251 | */ | |
3ab83521 | 252 | void machine_kexec(struct kimage *image) |
5234f5eb | 253 | { |
4bfaaef0 MD |
254 | unsigned long page_list[PAGES_NR]; |
255 | void *control_page; | |
fee7b0d8 | 256 | int save_ftrace_enabled; |
5234f5eb | 257 | |
fee7b0d8 | 258 | #ifdef CONFIG_KEXEC_JUMP |
6407df5c | 259 | if (image->preserve_context) |
fee7b0d8 HY |
260 | save_processor_state(); |
261 | #endif | |
262 | ||
263 | save_ftrace_enabled = __ftrace_enabled_save(); | |
f43fdad8 | 264 | |
5234f5eb EB |
265 | /* Interrupts aren't acceptable while we reboot */ |
266 | local_irq_disable(); | |
17f557e5 | 267 | hw_breakpoint_disable(); |
5234f5eb | 268 | |
fee7b0d8 HY |
269 | if (image->preserve_context) { |
270 | #ifdef CONFIG_X86_IO_APIC | |
271 | /* | |
272 | * We need to put APICs in legacy mode so that we can | |
273 | * get timer interrupts in second kernel. kexec/kdump | |
274 | * paths already have calls to disable_IO_APIC() in | |
275 | * one form or other. kexec jump path also need | |
276 | * one. | |
277 | */ | |
278 | disable_IO_APIC(); | |
279 | #endif | |
280 | } | |
281 | ||
4bfaaef0 | 282 | control_page = page_address(image->control_code_page) + PAGE_SIZE; |
fee7b0d8 | 283 | memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE); |
4bfaaef0 | 284 | |
e3ebadd9 | 285 | page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page); |
fee7b0d8 | 286 | page_list[VA_CONTROL_PAGE] = (unsigned long)control_page; |
4bfaaef0 MD |
287 | page_list[PA_TABLE_PAGE] = |
288 | (unsigned long)__pa(page_address(image->control_code_page)); | |
5234f5eb | 289 | |
fee7b0d8 HY |
290 | if (image->type == KEXEC_TYPE_DEFAULT) |
291 | page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page) | |
292 | << PAGE_SHIFT); | |
293 | ||
fef3a7a1 HY |
294 | /* |
295 | * The segment registers are funny things, they have both a | |
2a8a3d5b EB |
296 | * visible and an invisible part. Whenever the visible part is |
297 | * set to a specific selector, the invisible part is loaded | |
298 | * with from a table in memory. At no other time is the | |
299 | * descriptor table in memory accessed. | |
5234f5eb EB |
300 | * |
301 | * I take advantage of this here by force loading the | |
302 | * segments, before I zap the gdt with an invalid value. | |
303 | */ | |
304 | load_segments(); | |
fef3a7a1 HY |
305 | /* |
306 | * The gdt & idt are now invalid. | |
5234f5eb EB |
307 | * If you want to load them you must set up your own idt & gdt. |
308 | */ | |
fef3a7a1 HY |
309 | set_gdt(phys_to_virt(0), 0); |
310 | set_idt(phys_to_virt(0), 0); | |
4bfaaef0 | 311 | |
5234f5eb | 312 | /* now call it */ |
fee7b0d8 HY |
313 | image->start = relocate_kernel((unsigned long)image->head, |
314 | (unsigned long)page_list, | |
315 | image->start, | |
316 | image->preserve_context); | |
317 | ||
318 | #ifdef CONFIG_KEXEC_JUMP | |
6407df5c | 319 | if (image->preserve_context) |
fee7b0d8 HY |
320 | restore_processor_state(); |
321 | #endif | |
322 | ||
323 | __ftrace_enabled_restore(save_ftrace_enabled); | |
5234f5eb | 324 | } |
2c8c0e6b | 325 | |
fd59d231 KO |
326 | void arch_crash_save_vmcoreinfo(void) |
327 | { | |
629c8b4c | 328 | VMCOREINFO_SYMBOL(phys_base); |
69243f91 | 329 | VMCOREINFO_SYMBOL(init_level4_pgt); |
92df5c3e KO |
330 | |
331 | #ifdef CONFIG_NUMA | |
332 | VMCOREINFO_SYMBOL(node_data); | |
333 | VMCOREINFO_LENGTH(node_data, MAX_NUMNODES); | |
334 | #endif | |
b6085a86 ES |
335 | vmcoreinfo_append_str("KERNELOFFSET=%lx\n", |
336 | (unsigned long)&_text - __START_KERNEL); | |
fd59d231 KO |
337 | } |
338 | ||
cb105258 VG |
339 | /* arch-dependent functionality related to kexec file-based syscall */ |
340 | ||
74ca317c | 341 | #ifdef CONFIG_KEXEC_FILE |
cb105258 VG |
342 | int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, |
343 | unsigned long buf_len) | |
344 | { | |
345 | int i, ret = -ENOEXEC; | |
346 | struct kexec_file_ops *fops; | |
347 | ||
348 | for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) { | |
349 | fops = kexec_file_loaders[i]; | |
350 | if (!fops || !fops->probe) | |
351 | continue; | |
352 | ||
353 | ret = fops->probe(buf, buf_len); | |
354 | if (!ret) { | |
355 | image->fops = fops; | |
356 | return ret; | |
357 | } | |
358 | } | |
359 | ||
360 | return ret; | |
361 | } | |
362 | ||
363 | void *arch_kexec_kernel_image_load(struct kimage *image) | |
364 | { | |
dd5f7260 VG |
365 | vfree(image->arch.elf_headers); |
366 | image->arch.elf_headers = NULL; | |
367 | ||
cb105258 VG |
368 | if (!image->fops || !image->fops->load) |
369 | return ERR_PTR(-ENOEXEC); | |
370 | ||
371 | return image->fops->load(image, image->kernel_buf, | |
372 | image->kernel_buf_len, image->initrd_buf, | |
373 | image->initrd_buf_len, image->cmdline_buf, | |
374 | image->cmdline_buf_len); | |
375 | } | |
376 | ||
377 | int arch_kimage_file_post_load_cleanup(struct kimage *image) | |
378 | { | |
379 | if (!image->fops || !image->fops->cleanup) | |
380 | return 0; | |
381 | ||
27f48d3e | 382 | return image->fops->cleanup(image->image_loader_data); |
cb105258 | 383 | } |
12db5562 | 384 | |
8e7d8381 VG |
385 | int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel, |
386 | unsigned long kernel_len) | |
387 | { | |
388 | if (!image->fops || !image->fops->verify_sig) { | |
389 | pr_debug("kernel loader does not support signature verification."); | |
390 | return -EKEYREJECTED; | |
391 | } | |
392 | ||
393 | return image->fops->verify_sig(kernel, kernel_len); | |
394 | } | |
395 | ||
12db5562 VG |
396 | /* |
397 | * Apply purgatory relocations. | |
398 | * | |
399 | * ehdr: Pointer to elf headers | |
400 | * sechdrs: Pointer to section headers. | |
401 | * relsec: section index of SHT_RELA section. | |
402 | * | |
403 | * TODO: Some of the code belongs to generic code. Move that in kexec.c. | |
404 | */ | |
405 | int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr, | |
406 | Elf64_Shdr *sechdrs, unsigned int relsec) | |
407 | { | |
408 | unsigned int i; | |
409 | Elf64_Rela *rel; | |
410 | Elf64_Sym *sym; | |
411 | void *location; | |
412 | Elf64_Shdr *section, *symtabsec; | |
413 | unsigned long address, sec_base, value; | |
414 | const char *strtab, *name, *shstrtab; | |
415 | ||
416 | /* | |
417 | * ->sh_offset has been modified to keep the pointer to section | |
418 | * contents in memory | |
419 | */ | |
420 | rel = (void *)sechdrs[relsec].sh_offset; | |
421 | ||
422 | /* Section to which relocations apply */ | |
423 | section = &sechdrs[sechdrs[relsec].sh_info]; | |
424 | ||
425 | pr_debug("Applying relocate section %u to %u\n", relsec, | |
426 | sechdrs[relsec].sh_info); | |
427 | ||
428 | /* Associated symbol table */ | |
429 | symtabsec = &sechdrs[sechdrs[relsec].sh_link]; | |
430 | ||
431 | /* String table */ | |
432 | if (symtabsec->sh_link >= ehdr->e_shnum) { | |
433 | /* Invalid strtab section number */ | |
434 | pr_err("Invalid string table section index %d\n", | |
435 | symtabsec->sh_link); | |
436 | return -ENOEXEC; | |
437 | } | |
438 | ||
439 | strtab = (char *)sechdrs[symtabsec->sh_link].sh_offset; | |
440 | ||
441 | /* section header string table */ | |
442 | shstrtab = (char *)sechdrs[ehdr->e_shstrndx].sh_offset; | |
443 | ||
444 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { | |
445 | ||
446 | /* | |
447 | * rel[i].r_offset contains byte offset from beginning | |
448 | * of section to the storage unit affected. | |
449 | * | |
450 | * This is location to update (->sh_offset). This is temporary | |
451 | * buffer where section is currently loaded. This will finally | |
452 | * be loaded to a different address later, pointed to by | |
453 | * ->sh_addr. kexec takes care of moving it | |
454 | * (kexec_load_segment()). | |
455 | */ | |
456 | location = (void *)(section->sh_offset + rel[i].r_offset); | |
457 | ||
458 | /* Final address of the location */ | |
459 | address = section->sh_addr + rel[i].r_offset; | |
460 | ||
461 | /* | |
462 | * rel[i].r_info contains information about symbol table index | |
463 | * w.r.t which relocation must be made and type of relocation | |
464 | * to apply. ELF64_R_SYM() and ELF64_R_TYPE() macros get | |
465 | * these respectively. | |
466 | */ | |
467 | sym = (Elf64_Sym *)symtabsec->sh_offset + | |
468 | ELF64_R_SYM(rel[i].r_info); | |
469 | ||
470 | if (sym->st_name) | |
471 | name = strtab + sym->st_name; | |
472 | else | |
473 | name = shstrtab + sechdrs[sym->st_shndx].sh_name; | |
474 | ||
475 | pr_debug("Symbol: %s info: %02x shndx: %02x value=%llx size: %llx\n", | |
476 | name, sym->st_info, sym->st_shndx, sym->st_value, | |
477 | sym->st_size); | |
478 | ||
479 | if (sym->st_shndx == SHN_UNDEF) { | |
480 | pr_err("Undefined symbol: %s\n", name); | |
481 | return -ENOEXEC; | |
482 | } | |
483 | ||
484 | if (sym->st_shndx == SHN_COMMON) { | |
485 | pr_err("symbol '%s' in common section\n", name); | |
486 | return -ENOEXEC; | |
487 | } | |
488 | ||
489 | if (sym->st_shndx == SHN_ABS) | |
490 | sec_base = 0; | |
491 | else if (sym->st_shndx >= ehdr->e_shnum) { | |
492 | pr_err("Invalid section %d for symbol %s\n", | |
493 | sym->st_shndx, name); | |
494 | return -ENOEXEC; | |
495 | } else | |
496 | sec_base = sechdrs[sym->st_shndx].sh_addr; | |
497 | ||
498 | value = sym->st_value; | |
499 | value += sec_base; | |
500 | value += rel[i].r_addend; | |
501 | ||
502 | switch (ELF64_R_TYPE(rel[i].r_info)) { | |
503 | case R_X86_64_NONE: | |
504 | break; | |
505 | case R_X86_64_64: | |
506 | *(u64 *)location = value; | |
507 | break; | |
508 | case R_X86_64_32: | |
509 | *(u32 *)location = value; | |
510 | if (value != *(u32 *)location) | |
511 | goto overflow; | |
512 | break; | |
513 | case R_X86_64_32S: | |
514 | *(s32 *)location = value; | |
515 | if ((s64)value != *(s32 *)location) | |
516 | goto overflow; | |
517 | break; | |
518 | case R_X86_64_PC32: | |
519 | value -= (u64)address; | |
520 | *(u32 *)location = value; | |
521 | break; | |
522 | default: | |
523 | pr_err("Unknown rela relocation: %llu\n", | |
524 | ELF64_R_TYPE(rel[i].r_info)); | |
525 | return -ENOEXEC; | |
526 | } | |
527 | } | |
528 | return 0; | |
529 | ||
530 | overflow: | |
531 | pr_err("Overflow in relocation type %d value 0x%lx\n", | |
532 | (int)ELF64_R_TYPE(rel[i].r_info), value); | |
533 | return -ENOEXEC; | |
534 | } | |
74ca317c | 535 | #endif /* CONFIG_KEXEC_FILE */ |