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Commit | Line | Data |
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666bfddb VG |
1 | /* |
2 | * fs/proc/vmcore.c Interface for accessing the crash | |
3 | * dump from the system's previous life. | |
4 | * Heavily borrowed from fs/proc/kcore.c | |
5 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) | |
6 | * Copyright (C) IBM Corporation, 2004. All rights reserved | |
7 | * | |
8 | */ | |
9 | ||
666bfddb VG |
10 | #include <linux/mm.h> |
11 | #include <linux/proc_fs.h> | |
12 | #include <linux/user.h> | |
666bfddb VG |
13 | #include <linux/elf.h> |
14 | #include <linux/elfcore.h> | |
afeacc8c | 15 | #include <linux/export.h> |
5a0e3ad6 | 16 | #include <linux/slab.h> |
666bfddb | 17 | #include <linux/highmem.h> |
87ebdc00 | 18 | #include <linux/printk.h> |
666bfddb VG |
19 | #include <linux/bootmem.h> |
20 | #include <linux/init.h> | |
21 | #include <linux/crash_dump.h> | |
22 | #include <linux/list.h> | |
23 | #include <asm/uaccess.h> | |
24 | #include <asm/io.h> | |
25 | ||
26 | /* List representing chunks of contiguous memory areas and their offsets in | |
27 | * vmcore file. | |
28 | */ | |
29 | static LIST_HEAD(vmcore_list); | |
30 | ||
31 | /* Stores the pointer to the buffer containing kernel elf core headers. */ | |
32 | static char *elfcorebuf; | |
33 | static size_t elfcorebuf_sz; | |
34 | ||
35 | /* Total size of vmcore file. */ | |
36 | static u64 vmcore_size; | |
37 | ||
5aa140c2 | 38 | static struct proc_dir_entry *proc_vmcore = NULL; |
666bfddb | 39 | |
997c136f OH |
40 | /* |
41 | * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error | |
42 | * The called function has to take care of module refcounting. | |
43 | */ | |
44 | static int (*oldmem_pfn_is_ram)(unsigned long pfn); | |
45 | ||
46 | int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)) | |
47 | { | |
48 | if (oldmem_pfn_is_ram) | |
49 | return -EBUSY; | |
50 | oldmem_pfn_is_ram = fn; | |
51 | return 0; | |
52 | } | |
53 | EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram); | |
54 | ||
55 | void unregister_oldmem_pfn_is_ram(void) | |
56 | { | |
57 | oldmem_pfn_is_ram = NULL; | |
58 | wmb(); | |
59 | } | |
60 | EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram); | |
61 | ||
62 | static int pfn_is_ram(unsigned long pfn) | |
63 | { | |
64 | int (*fn)(unsigned long pfn); | |
65 | /* pfn is ram unless fn() checks pagetype */ | |
66 | int ret = 1; | |
67 | ||
68 | /* | |
69 | * Ask hypervisor if the pfn is really ram. | |
70 | * A ballooned page contains no data and reading from such a page | |
71 | * will cause high load in the hypervisor. | |
72 | */ | |
73 | fn = oldmem_pfn_is_ram; | |
74 | if (fn) | |
75 | ret = fn(pfn); | |
76 | ||
77 | return ret; | |
78 | } | |
79 | ||
666bfddb VG |
80 | /* Reads a page from the oldmem device from given offset. */ |
81 | static ssize_t read_from_oldmem(char *buf, size_t count, | |
9e9e3941 | 82 | u64 *ppos, int userbuf) |
666bfddb VG |
83 | { |
84 | unsigned long pfn, offset; | |
85 | size_t nr_bytes; | |
86 | ssize_t read = 0, tmp; | |
87 | ||
88 | if (!count) | |
89 | return 0; | |
90 | ||
91 | offset = (unsigned long)(*ppos % PAGE_SIZE); | |
92 | pfn = (unsigned long)(*ppos / PAGE_SIZE); | |
666bfddb VG |
93 | |
94 | do { | |
95 | if (count > (PAGE_SIZE - offset)) | |
96 | nr_bytes = PAGE_SIZE - offset; | |
97 | else | |
98 | nr_bytes = count; | |
99 | ||
997c136f OH |
100 | /* If pfn is not ram, return zeros for sparse dump files */ |
101 | if (pfn_is_ram(pfn) == 0) | |
102 | memset(buf, 0, nr_bytes); | |
103 | else { | |
104 | tmp = copy_oldmem_page(pfn, buf, nr_bytes, | |
105 | offset, userbuf); | |
106 | if (tmp < 0) | |
107 | return tmp; | |
108 | } | |
666bfddb VG |
109 | *ppos += nr_bytes; |
110 | count -= nr_bytes; | |
111 | buf += nr_bytes; | |
112 | read += nr_bytes; | |
113 | ++pfn; | |
114 | offset = 0; | |
115 | } while (count); | |
116 | ||
117 | return read; | |
118 | } | |
119 | ||
120 | /* Maps vmcore file offset to respective physical address in memroy. */ | |
121 | static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list, | |
122 | struct vmcore **m_ptr) | |
123 | { | |
124 | struct vmcore *m; | |
125 | u64 paddr; | |
126 | ||
127 | list_for_each_entry(m, vc_list, list) { | |
128 | u64 start, end; | |
129 | start = m->offset; | |
130 | end = m->offset + m->size - 1; | |
131 | if (offset >= start && offset <= end) { | |
132 | paddr = m->paddr + offset - start; | |
133 | *m_ptr = m; | |
134 | return paddr; | |
135 | } | |
136 | } | |
137 | *m_ptr = NULL; | |
138 | return 0; | |
139 | } | |
140 | ||
141 | /* Read from the ELF header and then the crash dump. On error, negative value is | |
142 | * returned otherwise number of bytes read are returned. | |
143 | */ | |
144 | static ssize_t read_vmcore(struct file *file, char __user *buffer, | |
145 | size_t buflen, loff_t *fpos) | |
146 | { | |
147 | ssize_t acc = 0, tmp; | |
80e8ff63 VG |
148 | size_t tsz; |
149 | u64 start, nr_bytes; | |
666bfddb VG |
150 | struct vmcore *curr_m = NULL; |
151 | ||
152 | if (buflen == 0 || *fpos >= vmcore_size) | |
153 | return 0; | |
154 | ||
155 | /* trim buflen to not go beyond EOF */ | |
156 | if (buflen > vmcore_size - *fpos) | |
157 | buflen = vmcore_size - *fpos; | |
158 | ||
159 | /* Read ELF core header */ | |
160 | if (*fpos < elfcorebuf_sz) { | |
161 | tsz = elfcorebuf_sz - *fpos; | |
162 | if (buflen < tsz) | |
163 | tsz = buflen; | |
164 | if (copy_to_user(buffer, elfcorebuf + *fpos, tsz)) | |
165 | return -EFAULT; | |
166 | buflen -= tsz; | |
167 | *fpos += tsz; | |
168 | buffer += tsz; | |
169 | acc += tsz; | |
170 | ||
171 | /* leave now if filled buffer already */ | |
172 | if (buflen == 0) | |
173 | return acc; | |
174 | } | |
175 | ||
176 | start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m); | |
177 | if (!curr_m) | |
178 | return -EINVAL; | |
666bfddb VG |
179 | |
180 | while (buflen) { | |
c2c1b089 ZY |
181 | tsz = min_t(size_t, buflen, PAGE_SIZE - (start & ~PAGE_MASK)); |
182 | ||
183 | /* Calculate left bytes in current memory segment. */ | |
184 | nr_bytes = (curr_m->size - (start - curr_m->paddr)); | |
185 | if (tsz > nr_bytes) | |
186 | tsz = nr_bytes; | |
187 | ||
666bfddb VG |
188 | tmp = read_from_oldmem(buffer, tsz, &start, 1); |
189 | if (tmp < 0) | |
190 | return tmp; | |
191 | buflen -= tsz; | |
192 | *fpos += tsz; | |
193 | buffer += tsz; | |
194 | acc += tsz; | |
195 | if (start >= (curr_m->paddr + curr_m->size)) { | |
196 | if (curr_m->list.next == &vmcore_list) | |
197 | return acc; /*EOF*/ | |
198 | curr_m = list_entry(curr_m->list.next, | |
199 | struct vmcore, list); | |
200 | start = curr_m->paddr; | |
201 | } | |
666bfddb VG |
202 | } |
203 | return acc; | |
204 | } | |
205 | ||
5aa140c2 | 206 | static const struct file_operations proc_vmcore_operations = { |
666bfddb | 207 | .read = read_vmcore, |
c227e690 | 208 | .llseek = default_llseek, |
666bfddb VG |
209 | }; |
210 | ||
211 | static struct vmcore* __init get_new_element(void) | |
212 | { | |
2f6d3110 | 213 | return kzalloc(sizeof(struct vmcore), GFP_KERNEL); |
666bfddb VG |
214 | } |
215 | ||
216 | static u64 __init get_vmcore_size_elf64(char *elfptr) | |
217 | { | |
218 | int i; | |
219 | u64 size; | |
220 | Elf64_Ehdr *ehdr_ptr; | |
221 | Elf64_Phdr *phdr_ptr; | |
222 | ||
223 | ehdr_ptr = (Elf64_Ehdr *)elfptr; | |
224 | phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); | |
225 | size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr)); | |
226 | for (i = 0; i < ehdr_ptr->e_phnum; i++) { | |
227 | size += phdr_ptr->p_memsz; | |
228 | phdr_ptr++; | |
229 | } | |
230 | return size; | |
231 | } | |
232 | ||
72658e9d VG |
233 | static u64 __init get_vmcore_size_elf32(char *elfptr) |
234 | { | |
235 | int i; | |
236 | u64 size; | |
237 | Elf32_Ehdr *ehdr_ptr; | |
238 | Elf32_Phdr *phdr_ptr; | |
239 | ||
240 | ehdr_ptr = (Elf32_Ehdr *)elfptr; | |
241 | phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); | |
242 | size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr)); | |
243 | for (i = 0; i < ehdr_ptr->e_phnum; i++) { | |
244 | size += phdr_ptr->p_memsz; | |
245 | phdr_ptr++; | |
246 | } | |
247 | return size; | |
248 | } | |
249 | ||
666bfddb VG |
250 | /* Merges all the PT_NOTE headers into one. */ |
251 | static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, | |
252 | struct list_head *vc_list) | |
253 | { | |
254 | int i, nr_ptnote=0, rc=0; | |
255 | char *tmp; | |
256 | Elf64_Ehdr *ehdr_ptr; | |
257 | Elf64_Phdr phdr, *phdr_ptr; | |
258 | Elf64_Nhdr *nhdr_ptr; | |
259 | u64 phdr_sz = 0, note_off; | |
260 | ||
261 | ehdr_ptr = (Elf64_Ehdr *)elfptr; | |
262 | phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); | |
263 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { | |
264 | int j; | |
265 | void *notes_section; | |
266 | struct vmcore *new; | |
267 | u64 offset, max_sz, sz, real_sz = 0; | |
268 | if (phdr_ptr->p_type != PT_NOTE) | |
269 | continue; | |
270 | nr_ptnote++; | |
271 | max_sz = phdr_ptr->p_memsz; | |
272 | offset = phdr_ptr->p_offset; | |
273 | notes_section = kmalloc(max_sz, GFP_KERNEL); | |
274 | if (!notes_section) | |
275 | return -ENOMEM; | |
276 | rc = read_from_oldmem(notes_section, max_sz, &offset, 0); | |
277 | if (rc < 0) { | |
278 | kfree(notes_section); | |
279 | return rc; | |
280 | } | |
281 | nhdr_ptr = notes_section; | |
282 | for (j = 0; j < max_sz; j += sz) { | |
283 | if (nhdr_ptr->n_namesz == 0) | |
284 | break; | |
285 | sz = sizeof(Elf64_Nhdr) + | |
286 | ((nhdr_ptr->n_namesz + 3) & ~3) + | |
287 | ((nhdr_ptr->n_descsz + 3) & ~3); | |
288 | real_sz += sz; | |
289 | nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz); | |
290 | } | |
291 | ||
292 | /* Add this contiguous chunk of notes section to vmcore list.*/ | |
293 | new = get_new_element(); | |
294 | if (!new) { | |
295 | kfree(notes_section); | |
296 | return -ENOMEM; | |
297 | } | |
298 | new->paddr = phdr_ptr->p_offset; | |
299 | new->size = real_sz; | |
300 | list_add_tail(&new->list, vc_list); | |
301 | phdr_sz += real_sz; | |
302 | kfree(notes_section); | |
303 | } | |
304 | ||
305 | /* Prepare merged PT_NOTE program header. */ | |
306 | phdr.p_type = PT_NOTE; | |
307 | phdr.p_flags = 0; | |
308 | note_off = sizeof(Elf64_Ehdr) + | |
309 | (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); | |
310 | phdr.p_offset = note_off; | |
311 | phdr.p_vaddr = phdr.p_paddr = 0; | |
312 | phdr.p_filesz = phdr.p_memsz = phdr_sz; | |
313 | phdr.p_align = 0; | |
314 | ||
315 | /* Add merged PT_NOTE program header*/ | |
316 | tmp = elfptr + sizeof(Elf64_Ehdr); | |
317 | memcpy(tmp, &phdr, sizeof(phdr)); | |
318 | tmp += sizeof(phdr); | |
319 | ||
320 | /* Remove unwanted PT_NOTE program headers. */ | |
321 | i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); | |
322 | *elfsz = *elfsz - i; | |
323 | memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); | |
324 | ||
325 | /* Modify e_phnum to reflect merged headers. */ | |
326 | ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; | |
327 | ||
328 | return 0; | |
329 | } | |
330 | ||
72658e9d VG |
331 | /* Merges all the PT_NOTE headers into one. */ |
332 | static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, | |
333 | struct list_head *vc_list) | |
334 | { | |
335 | int i, nr_ptnote=0, rc=0; | |
336 | char *tmp; | |
337 | Elf32_Ehdr *ehdr_ptr; | |
338 | Elf32_Phdr phdr, *phdr_ptr; | |
339 | Elf32_Nhdr *nhdr_ptr; | |
340 | u64 phdr_sz = 0, note_off; | |
341 | ||
342 | ehdr_ptr = (Elf32_Ehdr *)elfptr; | |
343 | phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); | |
344 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { | |
345 | int j; | |
346 | void *notes_section; | |
347 | struct vmcore *new; | |
348 | u64 offset, max_sz, sz, real_sz = 0; | |
349 | if (phdr_ptr->p_type != PT_NOTE) | |
350 | continue; | |
351 | nr_ptnote++; | |
352 | max_sz = phdr_ptr->p_memsz; | |
353 | offset = phdr_ptr->p_offset; | |
354 | notes_section = kmalloc(max_sz, GFP_KERNEL); | |
355 | if (!notes_section) | |
356 | return -ENOMEM; | |
357 | rc = read_from_oldmem(notes_section, max_sz, &offset, 0); | |
358 | if (rc < 0) { | |
359 | kfree(notes_section); | |
360 | return rc; | |
361 | } | |
362 | nhdr_ptr = notes_section; | |
363 | for (j = 0; j < max_sz; j += sz) { | |
364 | if (nhdr_ptr->n_namesz == 0) | |
365 | break; | |
366 | sz = sizeof(Elf32_Nhdr) + | |
367 | ((nhdr_ptr->n_namesz + 3) & ~3) + | |
368 | ((nhdr_ptr->n_descsz + 3) & ~3); | |
369 | real_sz += sz; | |
370 | nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz); | |
371 | } | |
372 | ||
373 | /* Add this contiguous chunk of notes section to vmcore list.*/ | |
374 | new = get_new_element(); | |
375 | if (!new) { | |
376 | kfree(notes_section); | |
377 | return -ENOMEM; | |
378 | } | |
379 | new->paddr = phdr_ptr->p_offset; | |
380 | new->size = real_sz; | |
381 | list_add_tail(&new->list, vc_list); | |
382 | phdr_sz += real_sz; | |
383 | kfree(notes_section); | |
384 | } | |
385 | ||
386 | /* Prepare merged PT_NOTE program header. */ | |
387 | phdr.p_type = PT_NOTE; | |
388 | phdr.p_flags = 0; | |
389 | note_off = sizeof(Elf32_Ehdr) + | |
390 | (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); | |
391 | phdr.p_offset = note_off; | |
392 | phdr.p_vaddr = phdr.p_paddr = 0; | |
393 | phdr.p_filesz = phdr.p_memsz = phdr_sz; | |
394 | phdr.p_align = 0; | |
395 | ||
396 | /* Add merged PT_NOTE program header*/ | |
397 | tmp = elfptr + sizeof(Elf32_Ehdr); | |
398 | memcpy(tmp, &phdr, sizeof(phdr)); | |
399 | tmp += sizeof(phdr); | |
400 | ||
401 | /* Remove unwanted PT_NOTE program headers. */ | |
402 | i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); | |
403 | *elfsz = *elfsz - i; | |
404 | memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); | |
405 | ||
406 | /* Modify e_phnum to reflect merged headers. */ | |
407 | ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; | |
408 | ||
409 | return 0; | |
410 | } | |
411 | ||
666bfddb VG |
412 | /* Add memory chunks represented by program headers to vmcore list. Also update |
413 | * the new offset fields of exported program headers. */ | |
414 | static int __init process_ptload_program_headers_elf64(char *elfptr, | |
415 | size_t elfsz, | |
416 | struct list_head *vc_list) | |
417 | { | |
418 | int i; | |
419 | Elf64_Ehdr *ehdr_ptr; | |
420 | Elf64_Phdr *phdr_ptr; | |
421 | loff_t vmcore_off; | |
422 | struct vmcore *new; | |
423 | ||
424 | ehdr_ptr = (Elf64_Ehdr *)elfptr; | |
425 | phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ | |
426 | ||
427 | /* First program header is PT_NOTE header. */ | |
428 | vmcore_off = sizeof(Elf64_Ehdr) + | |
429 | (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) + | |
430 | phdr_ptr->p_memsz; /* Note sections */ | |
431 | ||
432 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { | |
433 | if (phdr_ptr->p_type != PT_LOAD) | |
434 | continue; | |
435 | ||
436 | /* Add this contiguous chunk of memory to vmcore list.*/ | |
437 | new = get_new_element(); | |
438 | if (!new) | |
439 | return -ENOMEM; | |
440 | new->paddr = phdr_ptr->p_offset; | |
441 | new->size = phdr_ptr->p_memsz; | |
442 | list_add_tail(&new->list, vc_list); | |
443 | ||
444 | /* Update the program header offset. */ | |
445 | phdr_ptr->p_offset = vmcore_off; | |
446 | vmcore_off = vmcore_off + phdr_ptr->p_memsz; | |
447 | } | |
448 | return 0; | |
449 | } | |
450 | ||
72658e9d VG |
451 | static int __init process_ptload_program_headers_elf32(char *elfptr, |
452 | size_t elfsz, | |
453 | struct list_head *vc_list) | |
454 | { | |
455 | int i; | |
456 | Elf32_Ehdr *ehdr_ptr; | |
457 | Elf32_Phdr *phdr_ptr; | |
458 | loff_t vmcore_off; | |
459 | struct vmcore *new; | |
460 | ||
461 | ehdr_ptr = (Elf32_Ehdr *)elfptr; | |
462 | phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ | |
463 | ||
464 | /* First program header is PT_NOTE header. */ | |
465 | vmcore_off = sizeof(Elf32_Ehdr) + | |
466 | (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) + | |
467 | phdr_ptr->p_memsz; /* Note sections */ | |
468 | ||
469 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { | |
470 | if (phdr_ptr->p_type != PT_LOAD) | |
471 | continue; | |
472 | ||
473 | /* Add this contiguous chunk of memory to vmcore list.*/ | |
474 | new = get_new_element(); | |
475 | if (!new) | |
476 | return -ENOMEM; | |
477 | new->paddr = phdr_ptr->p_offset; | |
478 | new->size = phdr_ptr->p_memsz; | |
479 | list_add_tail(&new->list, vc_list); | |
480 | ||
481 | /* Update the program header offset */ | |
482 | phdr_ptr->p_offset = vmcore_off; | |
483 | vmcore_off = vmcore_off + phdr_ptr->p_memsz; | |
484 | } | |
485 | return 0; | |
486 | } | |
487 | ||
666bfddb VG |
488 | /* Sets offset fields of vmcore elements. */ |
489 | static void __init set_vmcore_list_offsets_elf64(char *elfptr, | |
490 | struct list_head *vc_list) | |
491 | { | |
492 | loff_t vmcore_off; | |
493 | Elf64_Ehdr *ehdr_ptr; | |
494 | struct vmcore *m; | |
495 | ||
496 | ehdr_ptr = (Elf64_Ehdr *)elfptr; | |
497 | ||
498 | /* Skip Elf header and program headers. */ | |
499 | vmcore_off = sizeof(Elf64_Ehdr) + | |
500 | (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr); | |
501 | ||
502 | list_for_each_entry(m, vc_list, list) { | |
503 | m->offset = vmcore_off; | |
504 | vmcore_off += m->size; | |
505 | } | |
506 | } | |
507 | ||
72658e9d VG |
508 | /* Sets offset fields of vmcore elements. */ |
509 | static void __init set_vmcore_list_offsets_elf32(char *elfptr, | |
510 | struct list_head *vc_list) | |
511 | { | |
512 | loff_t vmcore_off; | |
513 | Elf32_Ehdr *ehdr_ptr; | |
514 | struct vmcore *m; | |
515 | ||
516 | ehdr_ptr = (Elf32_Ehdr *)elfptr; | |
517 | ||
518 | /* Skip Elf header and program headers. */ | |
519 | vmcore_off = sizeof(Elf32_Ehdr) + | |
520 | (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr); | |
521 | ||
522 | list_for_each_entry(m, vc_list, list) { | |
523 | m->offset = vmcore_off; | |
524 | vmcore_off += m->size; | |
525 | } | |
526 | } | |
527 | ||
666bfddb VG |
528 | static int __init parse_crash_elf64_headers(void) |
529 | { | |
530 | int rc=0; | |
531 | Elf64_Ehdr ehdr; | |
532 | u64 addr; | |
533 | ||
534 | addr = elfcorehdr_addr; | |
535 | ||
536 | /* Read Elf header */ | |
537 | rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0); | |
538 | if (rc < 0) | |
539 | return rc; | |
540 | ||
541 | /* Do some basic Verification. */ | |
542 | if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || | |
543 | (ehdr.e_type != ET_CORE) || | |
9833c394 | 544 | !vmcore_elf64_check_arch(&ehdr) || |
666bfddb VG |
545 | ehdr.e_ident[EI_CLASS] != ELFCLASS64 || |
546 | ehdr.e_ident[EI_VERSION] != EV_CURRENT || | |
547 | ehdr.e_version != EV_CURRENT || | |
548 | ehdr.e_ehsize != sizeof(Elf64_Ehdr) || | |
549 | ehdr.e_phentsize != sizeof(Elf64_Phdr) || | |
550 | ehdr.e_phnum == 0) { | |
87ebdc00 | 551 | pr_warn("Warning: Core image elf header is not sane\n"); |
666bfddb VG |
552 | return -EINVAL; |
553 | } | |
554 | ||
555 | /* Read in all elf headers. */ | |
556 | elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr); | |
557 | elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL); | |
558 | if (!elfcorebuf) | |
559 | return -ENOMEM; | |
560 | addr = elfcorehdr_addr; | |
561 | rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0); | |
562 | if (rc < 0) { | |
563 | kfree(elfcorebuf); | |
564 | return rc; | |
565 | } | |
566 | ||
567 | /* Merge all PT_NOTE headers into one. */ | |
568 | rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list); | |
569 | if (rc) { | |
570 | kfree(elfcorebuf); | |
571 | return rc; | |
572 | } | |
573 | rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz, | |
574 | &vmcore_list); | |
575 | if (rc) { | |
576 | kfree(elfcorebuf); | |
577 | return rc; | |
578 | } | |
579 | set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list); | |
580 | return 0; | |
581 | } | |
582 | ||
72658e9d VG |
583 | static int __init parse_crash_elf32_headers(void) |
584 | { | |
585 | int rc=0; | |
586 | Elf32_Ehdr ehdr; | |
587 | u64 addr; | |
588 | ||
589 | addr = elfcorehdr_addr; | |
590 | ||
591 | /* Read Elf header */ | |
592 | rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0); | |
593 | if (rc < 0) | |
594 | return rc; | |
595 | ||
596 | /* Do some basic Verification. */ | |
597 | if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || | |
598 | (ehdr.e_type != ET_CORE) || | |
599 | !elf_check_arch(&ehdr) || | |
600 | ehdr.e_ident[EI_CLASS] != ELFCLASS32|| | |
601 | ehdr.e_ident[EI_VERSION] != EV_CURRENT || | |
602 | ehdr.e_version != EV_CURRENT || | |
603 | ehdr.e_ehsize != sizeof(Elf32_Ehdr) || | |
604 | ehdr.e_phentsize != sizeof(Elf32_Phdr) || | |
605 | ehdr.e_phnum == 0) { | |
87ebdc00 | 606 | pr_warn("Warning: Core image elf header is not sane\n"); |
72658e9d VG |
607 | return -EINVAL; |
608 | } | |
609 | ||
610 | /* Read in all elf headers. */ | |
611 | elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); | |
612 | elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL); | |
613 | if (!elfcorebuf) | |
614 | return -ENOMEM; | |
615 | addr = elfcorehdr_addr; | |
616 | rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0); | |
617 | if (rc < 0) { | |
618 | kfree(elfcorebuf); | |
619 | return rc; | |
620 | } | |
621 | ||
622 | /* Merge all PT_NOTE headers into one. */ | |
623 | rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list); | |
624 | if (rc) { | |
625 | kfree(elfcorebuf); | |
626 | return rc; | |
627 | } | |
628 | rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz, | |
629 | &vmcore_list); | |
630 | if (rc) { | |
631 | kfree(elfcorebuf); | |
632 | return rc; | |
633 | } | |
634 | set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list); | |
635 | return 0; | |
636 | } | |
637 | ||
666bfddb VG |
638 | static int __init parse_crash_elf_headers(void) |
639 | { | |
640 | unsigned char e_ident[EI_NIDENT]; | |
641 | u64 addr; | |
642 | int rc=0; | |
643 | ||
644 | addr = elfcorehdr_addr; | |
645 | rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0); | |
646 | if (rc < 0) | |
647 | return rc; | |
648 | if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) { | |
87ebdc00 | 649 | pr_warn("Warning: Core image elf header not found\n"); |
666bfddb VG |
650 | return -EINVAL; |
651 | } | |
652 | ||
653 | if (e_ident[EI_CLASS] == ELFCLASS64) { | |
654 | rc = parse_crash_elf64_headers(); | |
655 | if (rc) | |
656 | return rc; | |
657 | ||
658 | /* Determine vmcore size. */ | |
659 | vmcore_size = get_vmcore_size_elf64(elfcorebuf); | |
72658e9d VG |
660 | } else if (e_ident[EI_CLASS] == ELFCLASS32) { |
661 | rc = parse_crash_elf32_headers(); | |
662 | if (rc) | |
663 | return rc; | |
664 | ||
665 | /* Determine vmcore size. */ | |
666 | vmcore_size = get_vmcore_size_elf32(elfcorebuf); | |
666bfddb | 667 | } else { |
87ebdc00 | 668 | pr_warn("Warning: Core image elf header is not sane\n"); |
666bfddb VG |
669 | return -EINVAL; |
670 | } | |
671 | return 0; | |
672 | } | |
673 | ||
674 | /* Init function for vmcore module. */ | |
675 | static int __init vmcore_init(void) | |
676 | { | |
677 | int rc = 0; | |
678 | ||
679 | /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/ | |
85a0ee34 | 680 | if (!(is_vmcore_usable())) |
666bfddb VG |
681 | return rc; |
682 | rc = parse_crash_elf_headers(); | |
683 | if (rc) { | |
87ebdc00 | 684 | pr_warn("Kdump: vmcore not initialized\n"); |
666bfddb VG |
685 | return rc; |
686 | } | |
687 | ||
5aa140c2 | 688 | proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations); |
666bfddb VG |
689 | if (proc_vmcore) |
690 | proc_vmcore->size = vmcore_size; | |
691 | return 0; | |
692 | } | |
693 | module_init(vmcore_init) | |
16257393 MS |
694 | |
695 | /* Cleanup function for vmcore module. */ | |
696 | void vmcore_cleanup(void) | |
697 | { | |
698 | struct list_head *pos, *next; | |
699 | ||
700 | if (proc_vmcore) { | |
701 | remove_proc_entry(proc_vmcore->name, proc_vmcore->parent); | |
702 | proc_vmcore = NULL; | |
703 | } | |
704 | ||
705 | /* clear the vmcore list. */ | |
706 | list_for_each_safe(pos, next, &vmcore_list) { | |
707 | struct vmcore *m; | |
708 | ||
709 | m = list_entry(pos, struct vmcore, list); | |
710 | list_del(&m->list); | |
711 | kfree(m); | |
712 | } | |
713 | kfree(elfcorebuf); | |
714 | elfcorebuf = NULL; | |
715 | } | |
716 | EXPORT_SYMBOL_GPL(vmcore_cleanup); |