1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * fs/proc/vmcore.c Interface for accessing the crash |
4 | * dump from the system's previous life. |
5 | * Heavily borrowed from fs/proc/kcore.c |
6 | * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) |
7 | * Copyright (C) IBM Corporation, 2004. All rights reserved |
8 | * |
9 | */ |
10 | |
11 | #include <linux/mm.h> |
12 | #include <linux/kcore.h> |
13 | #include <linux/user.h> |
14 | #include <linux/elf.h> |
15 | #include <linux/elfcore.h> |
16 | #include <linux/export.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/highmem.h> |
19 | #include <linux/printk.h> |
20 | #include <linux/memblock.h> |
21 | #include <linux/init.h> |
22 | #include <linux/crash_dump.h> |
23 | #include <linux/list.h> |
24 | #include <linux/moduleparam.h> |
25 | #include <linux/mutex.h> |
26 | #include <linux/vmalloc.h> |
27 | #include <linux/pagemap.h> |
28 | #include <linux/uio.h> |
29 | #include <linux/cc_platform.h> |
30 | #include <asm/io.h> |
31 | #include "internal.h" |
32 | |
33 | /* List representing chunks of contiguous memory areas and their offsets in |
34 | * vmcore file. |
35 | */ |
36 | static LIST_HEAD(vmcore_list); |
37 | |
38 | /* Stores the pointer to the buffer containing kernel elf core headers. */ |
39 | static char *elfcorebuf; |
40 | static size_t elfcorebuf_sz; |
41 | static size_t elfcorebuf_sz_orig; |
42 | |
43 | static char *elfnotes_buf; |
44 | static size_t elfnotes_sz; |
45 | /* Size of all notes minus the device dump notes */ |
46 | static size_t elfnotes_orig_sz; |
47 | |
48 | /* Total size of vmcore file. */ |
49 | static u64 vmcore_size; |
50 | |
51 | static struct proc_dir_entry *proc_vmcore; |
52 | |
53 | #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP |
54 | /* Device Dump list and mutex to synchronize access to list */ |
55 | static LIST_HEAD(vmcoredd_list); |
56 | static DEFINE_MUTEX(vmcoredd_mutex); |
57 | |
58 | static bool vmcoredd_disabled; |
59 | core_param(novmcoredd, vmcoredd_disabled, bool, 0); |
60 | #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ |
61 | |
62 | /* Device Dump Size */ |
63 | static size_t vmcoredd_orig_sz; |
64 | |
65 | static DEFINE_SPINLOCK(vmcore_cb_lock); |
66 | DEFINE_STATIC_SRCU(vmcore_cb_srcu); |
67 | /* List of registered vmcore callbacks. */ |
68 | static LIST_HEAD(vmcore_cb_list); |
69 | /* Whether the vmcore has been opened once. */ |
70 | static bool vmcore_opened; |
71 | |
72 | void register_vmcore_cb(struct vmcore_cb *cb) |
73 | { |
74 | INIT_LIST_HEAD(list: &cb->next); |
75 | spin_lock(lock: &vmcore_cb_lock); |
76 | list_add_tail(new: &cb->next, head: &vmcore_cb_list); |
77 | /* |
78 | * Registering a vmcore callback after the vmcore was opened is |
79 | * very unusual (e.g., manual driver loading). |
80 | */ |
81 | if (vmcore_opened) |
82 | pr_warn_once("Unexpected vmcore callback registration\n" ); |
83 | spin_unlock(lock: &vmcore_cb_lock); |
84 | } |
85 | EXPORT_SYMBOL_GPL(register_vmcore_cb); |
86 | |
87 | void unregister_vmcore_cb(struct vmcore_cb *cb) |
88 | { |
89 | spin_lock(lock: &vmcore_cb_lock); |
90 | list_del_rcu(entry: &cb->next); |
91 | /* |
92 | * Unregistering a vmcore callback after the vmcore was opened is |
93 | * very unusual (e.g., forced driver removal), but we cannot stop |
94 | * unregistering. |
95 | */ |
96 | if (vmcore_opened) |
97 | pr_warn_once("Unexpected vmcore callback unregistration\n" ); |
98 | spin_unlock(lock: &vmcore_cb_lock); |
99 | |
100 | synchronize_srcu(ssp: &vmcore_cb_srcu); |
101 | } |
102 | EXPORT_SYMBOL_GPL(unregister_vmcore_cb); |
103 | |
104 | static bool pfn_is_ram(unsigned long pfn) |
105 | { |
106 | struct vmcore_cb *cb; |
107 | bool ret = true; |
108 | |
109 | list_for_each_entry_srcu(cb, &vmcore_cb_list, next, |
110 | srcu_read_lock_held(&vmcore_cb_srcu)) { |
111 | if (unlikely(!cb->pfn_is_ram)) |
112 | continue; |
113 | ret = cb->pfn_is_ram(cb, pfn); |
114 | if (!ret) |
115 | break; |
116 | } |
117 | |
118 | return ret; |
119 | } |
120 | |
121 | static int open_vmcore(struct inode *inode, struct file *file) |
122 | { |
123 | spin_lock(lock: &vmcore_cb_lock); |
124 | vmcore_opened = true; |
125 | spin_unlock(lock: &vmcore_cb_lock); |
126 | |
127 | return 0; |
128 | } |
129 | |
130 | /* Reads a page from the oldmem device from given offset. */ |
131 | ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, |
132 | u64 *ppos, bool encrypted) |
133 | { |
134 | unsigned long pfn, offset; |
135 | ssize_t nr_bytes; |
136 | ssize_t read = 0, tmp; |
137 | int idx; |
138 | |
139 | if (!count) |
140 | return 0; |
141 | |
142 | offset = (unsigned long)(*ppos % PAGE_SIZE); |
143 | pfn = (unsigned long)(*ppos / PAGE_SIZE); |
144 | |
145 | idx = srcu_read_lock(ssp: &vmcore_cb_srcu); |
146 | do { |
147 | if (count > (PAGE_SIZE - offset)) |
148 | nr_bytes = PAGE_SIZE - offset; |
149 | else |
150 | nr_bytes = count; |
151 | |
152 | /* If pfn is not ram, return zeros for sparse dump files */ |
153 | if (!pfn_is_ram(pfn)) { |
154 | tmp = iov_iter_zero(bytes: nr_bytes, iter); |
155 | } else { |
156 | if (encrypted) |
157 | tmp = copy_oldmem_page_encrypted(iter, pfn, |
158 | csize: nr_bytes, |
159 | offset); |
160 | else |
161 | tmp = copy_oldmem_page(i: iter, pfn, csize: nr_bytes, |
162 | offset); |
163 | } |
164 | if (tmp < nr_bytes) { |
165 | srcu_read_unlock(ssp: &vmcore_cb_srcu, idx); |
166 | return -EFAULT; |
167 | } |
168 | |
169 | *ppos += nr_bytes; |
170 | count -= nr_bytes; |
171 | read += nr_bytes; |
172 | ++pfn; |
173 | offset = 0; |
174 | } while (count); |
175 | srcu_read_unlock(ssp: &vmcore_cb_srcu, idx); |
176 | |
177 | return read; |
178 | } |
179 | |
180 | /* |
181 | * Architectures may override this function to allocate ELF header in 2nd kernel |
182 | */ |
183 | int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size) |
184 | { |
185 | return 0; |
186 | } |
187 | |
188 | /* |
189 | * Architectures may override this function to free header |
190 | */ |
191 | void __weak elfcorehdr_free(unsigned long long addr) |
192 | {} |
193 | |
194 | /* |
195 | * Architectures may override this function to read from ELF header |
196 | */ |
197 | ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) |
198 | { |
199 | struct kvec kvec = { .iov_base = buf, .iov_len = count }; |
200 | struct iov_iter iter; |
201 | |
202 | iov_iter_kvec(i: &iter, ITER_DEST, kvec: &kvec, nr_segs: 1, count); |
203 | |
204 | return read_from_oldmem(iter: &iter, count, ppos, encrypted: false); |
205 | } |
206 | |
207 | /* |
208 | * Architectures may override this function to read from notes sections |
209 | */ |
210 | ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) |
211 | { |
212 | struct kvec kvec = { .iov_base = buf, .iov_len = count }; |
213 | struct iov_iter iter; |
214 | |
215 | iov_iter_kvec(i: &iter, ITER_DEST, kvec: &kvec, nr_segs: 1, count); |
216 | |
217 | return read_from_oldmem(iter: &iter, count, ppos, |
218 | encrypted: cc_platform_has(attr: CC_ATTR_MEM_ENCRYPT)); |
219 | } |
220 | |
221 | /* |
222 | * Architectures may override this function to map oldmem |
223 | */ |
224 | int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma, |
225 | unsigned long from, unsigned long pfn, |
226 | unsigned long size, pgprot_t prot) |
227 | { |
228 | prot = pgprot_encrypted(prot); |
229 | return remap_pfn_range(vma, addr: from, pfn, size, prot); |
230 | } |
231 | |
232 | /* |
233 | * Architectures which support memory encryption override this. |
234 | */ |
235 | ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter, |
236 | unsigned long pfn, size_t csize, unsigned long offset) |
237 | { |
238 | return copy_oldmem_page(i: iter, pfn, csize, offset); |
239 | } |
240 | |
241 | #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP |
242 | static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size) |
243 | { |
244 | struct vmcoredd_node *dump; |
245 | u64 offset = 0; |
246 | int ret = 0; |
247 | size_t tsz; |
248 | char *buf; |
249 | |
250 | mutex_lock(&vmcoredd_mutex); |
251 | list_for_each_entry(dump, &vmcoredd_list, list) { |
252 | if (start < offset + dump->size) { |
253 | tsz = min(offset + (u64)dump->size - start, (u64)size); |
254 | buf = dump->buf + start - offset; |
255 | if (copy_to_iter(addr: buf, bytes: tsz, i: iter) < tsz) { |
256 | ret = -EFAULT; |
257 | goto out_unlock; |
258 | } |
259 | |
260 | size -= tsz; |
261 | start += tsz; |
262 | |
263 | /* Leave now if buffer filled already */ |
264 | if (!size) |
265 | goto out_unlock; |
266 | } |
267 | offset += dump->size; |
268 | } |
269 | |
270 | out_unlock: |
271 | mutex_unlock(lock: &vmcoredd_mutex); |
272 | return ret; |
273 | } |
274 | |
275 | #ifdef CONFIG_MMU |
276 | static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, |
277 | u64 start, size_t size) |
278 | { |
279 | struct vmcoredd_node *dump; |
280 | u64 offset = 0; |
281 | int ret = 0; |
282 | size_t tsz; |
283 | char *buf; |
284 | |
285 | mutex_lock(&vmcoredd_mutex); |
286 | list_for_each_entry(dump, &vmcoredd_list, list) { |
287 | if (start < offset + dump->size) { |
288 | tsz = min(offset + (u64)dump->size - start, (u64)size); |
289 | buf = dump->buf + start - offset; |
290 | if (remap_vmalloc_range_partial(vma, uaddr: dst, kaddr: buf, pgoff: 0, |
291 | size: tsz)) { |
292 | ret = -EFAULT; |
293 | goto out_unlock; |
294 | } |
295 | |
296 | size -= tsz; |
297 | start += tsz; |
298 | dst += tsz; |
299 | |
300 | /* Leave now if buffer filled already */ |
301 | if (!size) |
302 | goto out_unlock; |
303 | } |
304 | offset += dump->size; |
305 | } |
306 | |
307 | out_unlock: |
308 | mutex_unlock(lock: &vmcoredd_mutex); |
309 | return ret; |
310 | } |
311 | #endif /* CONFIG_MMU */ |
312 | #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ |
313 | |
314 | /* Read from the ELF header and then the crash dump. On error, negative value is |
315 | * returned otherwise number of bytes read are returned. |
316 | */ |
317 | static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos) |
318 | { |
319 | ssize_t acc = 0, tmp; |
320 | size_t tsz; |
321 | u64 start; |
322 | struct vmcore *m = NULL; |
323 | |
324 | if (!iov_iter_count(i: iter) || *fpos >= vmcore_size) |
325 | return 0; |
326 | |
327 | iov_iter_truncate(i: iter, count: vmcore_size - *fpos); |
328 | |
329 | /* Read ELF core header */ |
330 | if (*fpos < elfcorebuf_sz) { |
331 | tsz = min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter)); |
332 | if (copy_to_iter(addr: elfcorebuf + *fpos, bytes: tsz, i: iter) < tsz) |
333 | return -EFAULT; |
334 | *fpos += tsz; |
335 | acc += tsz; |
336 | |
337 | /* leave now if filled buffer already */ |
338 | if (!iov_iter_count(i: iter)) |
339 | return acc; |
340 | } |
341 | |
342 | /* Read ELF note segment */ |
343 | if (*fpos < elfcorebuf_sz + elfnotes_sz) { |
344 | void *kaddr; |
345 | |
346 | /* We add device dumps before other elf notes because the |
347 | * other elf notes may not fill the elf notes buffer |
348 | * completely and we will end up with zero-filled data |
349 | * between the elf notes and the device dumps. Tools will |
350 | * then try to decode this zero-filled data as valid notes |
351 | * and we don't want that. Hence, adding device dumps before |
352 | * the other elf notes ensure that zero-filled data can be |
353 | * avoided. |
354 | */ |
355 | #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP |
356 | /* Read device dumps */ |
357 | if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) { |
358 | tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - |
359 | (size_t)*fpos, iov_iter_count(iter)); |
360 | start = *fpos - elfcorebuf_sz; |
361 | if (vmcoredd_copy_dumps(iter, start, size: tsz)) |
362 | return -EFAULT; |
363 | |
364 | *fpos += tsz; |
365 | acc += tsz; |
366 | |
367 | /* leave now if filled buffer already */ |
368 | if (!iov_iter_count(i: iter)) |
369 | return acc; |
370 | } |
371 | #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ |
372 | |
373 | /* Read remaining elf notes */ |
374 | tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, |
375 | iov_iter_count(iter)); |
376 | kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz; |
377 | if (copy_to_iter(addr: kaddr, bytes: tsz, i: iter) < tsz) |
378 | return -EFAULT; |
379 | |
380 | *fpos += tsz; |
381 | acc += tsz; |
382 | |
383 | /* leave now if filled buffer already */ |
384 | if (!iov_iter_count(i: iter)) |
385 | return acc; |
386 | } |
387 | |
388 | list_for_each_entry(m, &vmcore_list, list) { |
389 | if (*fpos < m->offset + m->size) { |
390 | tsz = (size_t)min_t(unsigned long long, |
391 | m->offset + m->size - *fpos, |
392 | iov_iter_count(iter)); |
393 | start = m->paddr + *fpos - m->offset; |
394 | tmp = read_from_oldmem(iter, count: tsz, ppos: &start, |
395 | encrypted: cc_platform_has(attr: CC_ATTR_MEM_ENCRYPT)); |
396 | if (tmp < 0) |
397 | return tmp; |
398 | *fpos += tsz; |
399 | acc += tsz; |
400 | |
401 | /* leave now if filled buffer already */ |
402 | if (!iov_iter_count(i: iter)) |
403 | return acc; |
404 | } |
405 | } |
406 | |
407 | return acc; |
408 | } |
409 | |
410 | static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter) |
411 | { |
412 | return __read_vmcore(iter, fpos: &iocb->ki_pos); |
413 | } |
414 | |
415 | /* |
416 | * The vmcore fault handler uses the page cache and fills data using the |
417 | * standard __read_vmcore() function. |
418 | * |
419 | * On s390 the fault handler is used for memory regions that can't be mapped |
420 | * directly with remap_pfn_range(). |
421 | */ |
422 | static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf) |
423 | { |
424 | #ifdef CONFIG_S390 |
425 | struct address_space *mapping = vmf->vma->vm_file->f_mapping; |
426 | pgoff_t index = vmf->pgoff; |
427 | struct iov_iter iter; |
428 | struct kvec kvec; |
429 | struct page *page; |
430 | loff_t offset; |
431 | int rc; |
432 | |
433 | page = find_or_create_page(mapping, index, GFP_KERNEL); |
434 | if (!page) |
435 | return VM_FAULT_OOM; |
436 | if (!PageUptodate(page)) { |
437 | offset = (loff_t) index << PAGE_SHIFT; |
438 | kvec.iov_base = page_address(page); |
439 | kvec.iov_len = PAGE_SIZE; |
440 | iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE); |
441 | |
442 | rc = __read_vmcore(&iter, &offset); |
443 | if (rc < 0) { |
444 | unlock_page(page); |
445 | put_page(page); |
446 | return vmf_error(rc); |
447 | } |
448 | SetPageUptodate(page); |
449 | } |
450 | unlock_page(page); |
451 | vmf->page = page; |
452 | return 0; |
453 | #else |
454 | return VM_FAULT_SIGBUS; |
455 | #endif |
456 | } |
457 | |
458 | static const struct vm_operations_struct vmcore_mmap_ops = { |
459 | .fault = mmap_vmcore_fault, |
460 | }; |
461 | |
462 | /** |
463 | * vmcore_alloc_buf - allocate buffer in vmalloc memory |
464 | * @size: size of buffer |
465 | * |
466 | * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap |
467 | * the buffer to user-space by means of remap_vmalloc_range(). |
468 | * |
469 | * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is |
470 | * disabled and there's no need to allow users to mmap the buffer. |
471 | */ |
472 | static inline char *vmcore_alloc_buf(size_t size) |
473 | { |
474 | #ifdef CONFIG_MMU |
475 | return vmalloc_user(size); |
476 | #else |
477 | return vzalloc(size); |
478 | #endif |
479 | } |
480 | |
481 | /* |
482 | * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is |
483 | * essential for mmap_vmcore() in order to map physically |
484 | * non-contiguous objects (ELF header, ELF note segment and memory |
485 | * regions in the 1st kernel pointed to by PT_LOAD entries) into |
486 | * virtually contiguous user-space in ELF layout. |
487 | */ |
488 | #ifdef CONFIG_MMU |
489 | /* |
490 | * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages |
491 | * reported as not being ram with the zero page. |
492 | * |
493 | * @vma: vm_area_struct describing requested mapping |
494 | * @from: start remapping from |
495 | * @pfn: page frame number to start remapping to |
496 | * @size: remapping size |
497 | * @prot: protection bits |
498 | * |
499 | * Returns zero on success, -EAGAIN on failure. |
500 | */ |
501 | static int remap_oldmem_pfn_checked(struct vm_area_struct *vma, |
502 | unsigned long from, unsigned long pfn, |
503 | unsigned long size, pgprot_t prot) |
504 | { |
505 | unsigned long map_size; |
506 | unsigned long pos_start, pos_end, pos; |
507 | unsigned long zeropage_pfn = my_zero_pfn(addr: 0); |
508 | size_t len = 0; |
509 | |
510 | pos_start = pfn; |
511 | pos_end = pfn + (size >> PAGE_SHIFT); |
512 | |
513 | for (pos = pos_start; pos < pos_end; ++pos) { |
514 | if (!pfn_is_ram(pfn: pos)) { |
515 | /* |
516 | * We hit a page which is not ram. Remap the continuous |
517 | * region between pos_start and pos-1 and replace |
518 | * the non-ram page at pos with the zero page. |
519 | */ |
520 | if (pos > pos_start) { |
521 | /* Remap continuous region */ |
522 | map_size = (pos - pos_start) << PAGE_SHIFT; |
523 | if (remap_oldmem_pfn_range(vma, from: from + len, |
524 | pfn: pos_start, size: map_size, |
525 | prot)) |
526 | goto fail; |
527 | len += map_size; |
528 | } |
529 | /* Remap the zero page */ |
530 | if (remap_oldmem_pfn_range(vma, from: from + len, |
531 | pfn: zeropage_pfn, |
532 | PAGE_SIZE, prot)) |
533 | goto fail; |
534 | len += PAGE_SIZE; |
535 | pos_start = pos + 1; |
536 | } |
537 | } |
538 | if (pos > pos_start) { |
539 | /* Remap the rest */ |
540 | map_size = (pos - pos_start) << PAGE_SHIFT; |
541 | if (remap_oldmem_pfn_range(vma, from: from + len, pfn: pos_start, |
542 | size: map_size, prot)) |
543 | goto fail; |
544 | } |
545 | return 0; |
546 | fail: |
547 | do_munmap(vma->vm_mm, from, len, NULL); |
548 | return -EAGAIN; |
549 | } |
550 | |
551 | static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma, |
552 | unsigned long from, unsigned long pfn, |
553 | unsigned long size, pgprot_t prot) |
554 | { |
555 | int ret, idx; |
556 | |
557 | /* |
558 | * Check if a callback was registered to avoid looping over all |
559 | * pages without a reason. |
560 | */ |
561 | idx = srcu_read_lock(ssp: &vmcore_cb_srcu); |
562 | if (!list_empty(head: &vmcore_cb_list)) |
563 | ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot); |
564 | else |
565 | ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot); |
566 | srcu_read_unlock(ssp: &vmcore_cb_srcu, idx); |
567 | return ret; |
568 | } |
569 | |
570 | static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) |
571 | { |
572 | size_t size = vma->vm_end - vma->vm_start; |
573 | u64 start, end, len, tsz; |
574 | struct vmcore *m; |
575 | |
576 | start = (u64)vma->vm_pgoff << PAGE_SHIFT; |
577 | end = start + size; |
578 | |
579 | if (size > vmcore_size || end > vmcore_size) |
580 | return -EINVAL; |
581 | |
582 | if (vma->vm_flags & (VM_WRITE | VM_EXEC)) |
583 | return -EPERM; |
584 | |
585 | vm_flags_mod(vma, VM_MIXEDMAP, VM_MAYWRITE | VM_MAYEXEC); |
586 | vma->vm_ops = &vmcore_mmap_ops; |
587 | |
588 | len = 0; |
589 | |
590 | if (start < elfcorebuf_sz) { |
591 | u64 pfn; |
592 | |
593 | tsz = min(elfcorebuf_sz - (size_t)start, size); |
594 | pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT; |
595 | if (remap_pfn_range(vma, addr: vma->vm_start, pfn, size: tsz, |
596 | vma->vm_page_prot)) |
597 | return -EAGAIN; |
598 | size -= tsz; |
599 | start += tsz; |
600 | len += tsz; |
601 | |
602 | if (size == 0) |
603 | return 0; |
604 | } |
605 | |
606 | if (start < elfcorebuf_sz + elfnotes_sz) { |
607 | void *kaddr; |
608 | |
609 | /* We add device dumps before other elf notes because the |
610 | * other elf notes may not fill the elf notes buffer |
611 | * completely and we will end up with zero-filled data |
612 | * between the elf notes and the device dumps. Tools will |
613 | * then try to decode this zero-filled data as valid notes |
614 | * and we don't want that. Hence, adding device dumps before |
615 | * the other elf notes ensure that zero-filled data can be |
616 | * avoided. This also ensures that the device dumps and |
617 | * other elf notes can be properly mmaped at page aligned |
618 | * address. |
619 | */ |
620 | #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP |
621 | /* Read device dumps */ |
622 | if (start < elfcorebuf_sz + vmcoredd_orig_sz) { |
623 | u64 start_off; |
624 | |
625 | tsz = min(elfcorebuf_sz + vmcoredd_orig_sz - |
626 | (size_t)start, size); |
627 | start_off = start - elfcorebuf_sz; |
628 | if (vmcoredd_mmap_dumps(vma, dst: vma->vm_start + len, |
629 | start: start_off, size: tsz)) |
630 | goto fail; |
631 | |
632 | size -= tsz; |
633 | start += tsz; |
634 | len += tsz; |
635 | |
636 | /* leave now if filled buffer already */ |
637 | if (!size) |
638 | return 0; |
639 | } |
640 | #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ |
641 | |
642 | /* Read remaining elf notes */ |
643 | tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size); |
644 | kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz; |
645 | if (remap_vmalloc_range_partial(vma, uaddr: vma->vm_start + len, |
646 | kaddr, pgoff: 0, size: tsz)) |
647 | goto fail; |
648 | |
649 | size -= tsz; |
650 | start += tsz; |
651 | len += tsz; |
652 | |
653 | if (size == 0) |
654 | return 0; |
655 | } |
656 | |
657 | list_for_each_entry(m, &vmcore_list, list) { |
658 | if (start < m->offset + m->size) { |
659 | u64 paddr = 0; |
660 | |
661 | tsz = (size_t)min_t(unsigned long long, |
662 | m->offset + m->size - start, size); |
663 | paddr = m->paddr + start - m->offset; |
664 | if (vmcore_remap_oldmem_pfn(vma, from: vma->vm_start + len, |
665 | pfn: paddr >> PAGE_SHIFT, size: tsz, |
666 | prot: vma->vm_page_prot)) |
667 | goto fail; |
668 | size -= tsz; |
669 | start += tsz; |
670 | len += tsz; |
671 | |
672 | if (size == 0) |
673 | return 0; |
674 | } |
675 | } |
676 | |
677 | return 0; |
678 | fail: |
679 | do_munmap(vma->vm_mm, vma->vm_start, len, NULL); |
680 | return -EAGAIN; |
681 | } |
682 | #else |
683 | static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) |
684 | { |
685 | return -ENOSYS; |
686 | } |
687 | #endif |
688 | |
689 | static const struct proc_ops vmcore_proc_ops = { |
690 | .proc_open = open_vmcore, |
691 | .proc_read_iter = read_vmcore, |
692 | .proc_lseek = default_llseek, |
693 | .proc_mmap = mmap_vmcore, |
694 | }; |
695 | |
696 | static struct vmcore* __init get_new_element(void) |
697 | { |
698 | return kzalloc(size: sizeof(struct vmcore), GFP_KERNEL); |
699 | } |
700 | |
701 | static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz, |
702 | struct list_head *vc_list) |
703 | { |
704 | u64 size; |
705 | struct vmcore *m; |
706 | |
707 | size = elfsz + elfnotesegsz; |
708 | list_for_each_entry(m, vc_list, list) { |
709 | size += m->size; |
710 | } |
711 | return size; |
712 | } |
713 | |
714 | /** |
715 | * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry |
716 | * |
717 | * @ehdr_ptr: ELF header |
718 | * |
719 | * This function updates p_memsz member of each PT_NOTE entry in the |
720 | * program header table pointed to by @ehdr_ptr to real size of ELF |
721 | * note segment. |
722 | */ |
723 | static int __init (const Elf64_Ehdr *ehdr_ptr) |
724 | { |
725 | int i, rc=0; |
726 | Elf64_Phdr *phdr_ptr; |
727 | Elf64_Nhdr *nhdr_ptr; |
728 | |
729 | phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); |
730 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
731 | void *notes_section; |
732 | u64 offset, max_sz, sz, real_sz = 0; |
733 | if (phdr_ptr->p_type != PT_NOTE) |
734 | continue; |
735 | max_sz = phdr_ptr->p_memsz; |
736 | offset = phdr_ptr->p_offset; |
737 | notes_section = kmalloc(size: max_sz, GFP_KERNEL); |
738 | if (!notes_section) |
739 | return -ENOMEM; |
740 | rc = elfcorehdr_read_notes(buf: notes_section, count: max_sz, ppos: &offset); |
741 | if (rc < 0) { |
742 | kfree(objp: notes_section); |
743 | return rc; |
744 | } |
745 | nhdr_ptr = notes_section; |
746 | while (nhdr_ptr->n_namesz != 0) { |
747 | sz = sizeof(Elf64_Nhdr) + |
748 | (((u64)nhdr_ptr->n_namesz + 3) & ~3) + |
749 | (((u64)nhdr_ptr->n_descsz + 3) & ~3); |
750 | if ((real_sz + sz) > max_sz) { |
751 | pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n" , |
752 | nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); |
753 | break; |
754 | } |
755 | real_sz += sz; |
756 | nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz); |
757 | } |
758 | kfree(objp: notes_section); |
759 | phdr_ptr->p_memsz = real_sz; |
760 | if (real_sz == 0) { |
761 | pr_warn("Warning: Zero PT_NOTE entries found\n" ); |
762 | } |
763 | } |
764 | |
765 | return 0; |
766 | } |
767 | |
768 | /** |
769 | * get_note_number_and_size_elf64 - get the number of PT_NOTE program |
770 | * headers and sum of real size of their ELF note segment headers and |
771 | * data. |
772 | * |
773 | * @ehdr_ptr: ELF header |
774 | * @nr_ptnote: buffer for the number of PT_NOTE program headers |
775 | * @sz_ptnote: buffer for size of unique PT_NOTE program header |
776 | * |
777 | * This function is used to merge multiple PT_NOTE program headers |
778 | * into a unique single one. The resulting unique entry will have |
779 | * @sz_ptnote in its phdr->p_mem. |
780 | * |
781 | * It is assumed that program headers with PT_NOTE type pointed to by |
782 | * @ehdr_ptr has already been updated by update_note_header_size_elf64 |
783 | * and each of PT_NOTE program headers has actual ELF note segment |
784 | * size in its p_memsz member. |
785 | */ |
786 | static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr, |
787 | int *nr_ptnote, u64 *sz_ptnote) |
788 | { |
789 | int i; |
790 | Elf64_Phdr *phdr_ptr; |
791 | |
792 | *nr_ptnote = *sz_ptnote = 0; |
793 | |
794 | phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); |
795 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
796 | if (phdr_ptr->p_type != PT_NOTE) |
797 | continue; |
798 | *nr_ptnote += 1; |
799 | *sz_ptnote += phdr_ptr->p_memsz; |
800 | } |
801 | |
802 | return 0; |
803 | } |
804 | |
805 | /** |
806 | * copy_notes_elf64 - copy ELF note segments in a given buffer |
807 | * |
808 | * @ehdr_ptr: ELF header |
809 | * @notes_buf: buffer into which ELF note segments are copied |
810 | * |
811 | * This function is used to copy ELF note segment in the 1st kernel |
812 | * into the buffer @notes_buf in the 2nd kernel. It is assumed that |
813 | * size of the buffer @notes_buf is equal to or larger than sum of the |
814 | * real ELF note segment headers and data. |
815 | * |
816 | * It is assumed that program headers with PT_NOTE type pointed to by |
817 | * @ehdr_ptr has already been updated by update_note_header_size_elf64 |
818 | * and each of PT_NOTE program headers has actual ELF note segment |
819 | * size in its p_memsz member. |
820 | */ |
821 | static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf) |
822 | { |
823 | int i, rc=0; |
824 | Elf64_Phdr *phdr_ptr; |
825 | |
826 | phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1); |
827 | |
828 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
829 | u64 offset; |
830 | if (phdr_ptr->p_type != PT_NOTE) |
831 | continue; |
832 | offset = phdr_ptr->p_offset; |
833 | rc = elfcorehdr_read_notes(buf: notes_buf, count: phdr_ptr->p_memsz, |
834 | ppos: &offset); |
835 | if (rc < 0) |
836 | return rc; |
837 | notes_buf += phdr_ptr->p_memsz; |
838 | } |
839 | |
840 | return 0; |
841 | } |
842 | |
843 | /* Merges all the PT_NOTE headers into one. */ |
844 | static int __init (char *elfptr, size_t *elfsz, |
845 | char **notes_buf, size_t *notes_sz) |
846 | { |
847 | int i, nr_ptnote=0, rc=0; |
848 | char *tmp; |
849 | Elf64_Ehdr *ehdr_ptr; |
850 | Elf64_Phdr phdr; |
851 | u64 phdr_sz = 0, note_off; |
852 | |
853 | ehdr_ptr = (Elf64_Ehdr *)elfptr; |
854 | |
855 | rc = update_note_header_size_elf64(ehdr_ptr); |
856 | if (rc < 0) |
857 | return rc; |
858 | |
859 | rc = get_note_number_and_size_elf64(ehdr_ptr, nr_ptnote: &nr_ptnote, sz_ptnote: &phdr_sz); |
860 | if (rc < 0) |
861 | return rc; |
862 | |
863 | *notes_sz = roundup(phdr_sz, PAGE_SIZE); |
864 | *notes_buf = vmcore_alloc_buf(size: *notes_sz); |
865 | if (!*notes_buf) |
866 | return -ENOMEM; |
867 | |
868 | rc = copy_notes_elf64(ehdr_ptr, notes_buf: *notes_buf); |
869 | if (rc < 0) |
870 | return rc; |
871 | |
872 | /* Prepare merged PT_NOTE program header. */ |
873 | phdr.p_type = PT_NOTE; |
874 | phdr.p_flags = 0; |
875 | note_off = sizeof(Elf64_Ehdr) + |
876 | (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); |
877 | phdr.p_offset = roundup(note_off, PAGE_SIZE); |
878 | phdr.p_vaddr = phdr.p_paddr = 0; |
879 | phdr.p_filesz = phdr.p_memsz = phdr_sz; |
880 | phdr.p_align = 4; |
881 | |
882 | /* Add merged PT_NOTE program header*/ |
883 | tmp = elfptr + sizeof(Elf64_Ehdr); |
884 | memcpy(tmp, &phdr, sizeof(phdr)); |
885 | tmp += sizeof(phdr); |
886 | |
887 | /* Remove unwanted PT_NOTE program headers. */ |
888 | i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); |
889 | *elfsz = *elfsz - i; |
890 | memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); |
891 | memset(elfptr + *elfsz, 0, i); |
892 | *elfsz = roundup(*elfsz, PAGE_SIZE); |
893 | |
894 | /* Modify e_phnum to reflect merged headers. */ |
895 | ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; |
896 | |
897 | /* Store the size of all notes. We need this to update the note |
898 | * header when the device dumps will be added. |
899 | */ |
900 | elfnotes_orig_sz = phdr.p_memsz; |
901 | |
902 | return 0; |
903 | } |
904 | |
905 | /** |
906 | * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry |
907 | * |
908 | * @ehdr_ptr: ELF header |
909 | * |
910 | * This function updates p_memsz member of each PT_NOTE entry in the |
911 | * program header table pointed to by @ehdr_ptr to real size of ELF |
912 | * note segment. |
913 | */ |
914 | static int __init (const Elf32_Ehdr *ehdr_ptr) |
915 | { |
916 | int i, rc=0; |
917 | Elf32_Phdr *phdr_ptr; |
918 | Elf32_Nhdr *nhdr_ptr; |
919 | |
920 | phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); |
921 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
922 | void *notes_section; |
923 | u64 offset, max_sz, sz, real_sz = 0; |
924 | if (phdr_ptr->p_type != PT_NOTE) |
925 | continue; |
926 | max_sz = phdr_ptr->p_memsz; |
927 | offset = phdr_ptr->p_offset; |
928 | notes_section = kmalloc(size: max_sz, GFP_KERNEL); |
929 | if (!notes_section) |
930 | return -ENOMEM; |
931 | rc = elfcorehdr_read_notes(buf: notes_section, count: max_sz, ppos: &offset); |
932 | if (rc < 0) { |
933 | kfree(objp: notes_section); |
934 | return rc; |
935 | } |
936 | nhdr_ptr = notes_section; |
937 | while (nhdr_ptr->n_namesz != 0) { |
938 | sz = sizeof(Elf32_Nhdr) + |
939 | (((u64)nhdr_ptr->n_namesz + 3) & ~3) + |
940 | (((u64)nhdr_ptr->n_descsz + 3) & ~3); |
941 | if ((real_sz + sz) > max_sz) { |
942 | pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n" , |
943 | nhdr_ptr->n_namesz, nhdr_ptr->n_descsz); |
944 | break; |
945 | } |
946 | real_sz += sz; |
947 | nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz); |
948 | } |
949 | kfree(objp: notes_section); |
950 | phdr_ptr->p_memsz = real_sz; |
951 | if (real_sz == 0) { |
952 | pr_warn("Warning: Zero PT_NOTE entries found\n" ); |
953 | } |
954 | } |
955 | |
956 | return 0; |
957 | } |
958 | |
959 | /** |
960 | * get_note_number_and_size_elf32 - get the number of PT_NOTE program |
961 | * headers and sum of real size of their ELF note segment headers and |
962 | * data. |
963 | * |
964 | * @ehdr_ptr: ELF header |
965 | * @nr_ptnote: buffer for the number of PT_NOTE program headers |
966 | * @sz_ptnote: buffer for size of unique PT_NOTE program header |
967 | * |
968 | * This function is used to merge multiple PT_NOTE program headers |
969 | * into a unique single one. The resulting unique entry will have |
970 | * @sz_ptnote in its phdr->p_mem. |
971 | * |
972 | * It is assumed that program headers with PT_NOTE type pointed to by |
973 | * @ehdr_ptr has already been updated by update_note_header_size_elf32 |
974 | * and each of PT_NOTE program headers has actual ELF note segment |
975 | * size in its p_memsz member. |
976 | */ |
977 | static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr, |
978 | int *nr_ptnote, u64 *sz_ptnote) |
979 | { |
980 | int i; |
981 | Elf32_Phdr *phdr_ptr; |
982 | |
983 | *nr_ptnote = *sz_ptnote = 0; |
984 | |
985 | phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); |
986 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
987 | if (phdr_ptr->p_type != PT_NOTE) |
988 | continue; |
989 | *nr_ptnote += 1; |
990 | *sz_ptnote += phdr_ptr->p_memsz; |
991 | } |
992 | |
993 | return 0; |
994 | } |
995 | |
996 | /** |
997 | * copy_notes_elf32 - copy ELF note segments in a given buffer |
998 | * |
999 | * @ehdr_ptr: ELF header |
1000 | * @notes_buf: buffer into which ELF note segments are copied |
1001 | * |
1002 | * This function is used to copy ELF note segment in the 1st kernel |
1003 | * into the buffer @notes_buf in the 2nd kernel. It is assumed that |
1004 | * size of the buffer @notes_buf is equal to or larger than sum of the |
1005 | * real ELF note segment headers and data. |
1006 | * |
1007 | * It is assumed that program headers with PT_NOTE type pointed to by |
1008 | * @ehdr_ptr has already been updated by update_note_header_size_elf32 |
1009 | * and each of PT_NOTE program headers has actual ELF note segment |
1010 | * size in its p_memsz member. |
1011 | */ |
1012 | static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf) |
1013 | { |
1014 | int i, rc=0; |
1015 | Elf32_Phdr *phdr_ptr; |
1016 | |
1017 | phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1); |
1018 | |
1019 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
1020 | u64 offset; |
1021 | if (phdr_ptr->p_type != PT_NOTE) |
1022 | continue; |
1023 | offset = phdr_ptr->p_offset; |
1024 | rc = elfcorehdr_read_notes(buf: notes_buf, count: phdr_ptr->p_memsz, |
1025 | ppos: &offset); |
1026 | if (rc < 0) |
1027 | return rc; |
1028 | notes_buf += phdr_ptr->p_memsz; |
1029 | } |
1030 | |
1031 | return 0; |
1032 | } |
1033 | |
1034 | /* Merges all the PT_NOTE headers into one. */ |
1035 | static int __init (char *elfptr, size_t *elfsz, |
1036 | char **notes_buf, size_t *notes_sz) |
1037 | { |
1038 | int i, nr_ptnote=0, rc=0; |
1039 | char *tmp; |
1040 | Elf32_Ehdr *ehdr_ptr; |
1041 | Elf32_Phdr phdr; |
1042 | u64 phdr_sz = 0, note_off; |
1043 | |
1044 | ehdr_ptr = (Elf32_Ehdr *)elfptr; |
1045 | |
1046 | rc = update_note_header_size_elf32(ehdr_ptr); |
1047 | if (rc < 0) |
1048 | return rc; |
1049 | |
1050 | rc = get_note_number_and_size_elf32(ehdr_ptr, nr_ptnote: &nr_ptnote, sz_ptnote: &phdr_sz); |
1051 | if (rc < 0) |
1052 | return rc; |
1053 | |
1054 | *notes_sz = roundup(phdr_sz, PAGE_SIZE); |
1055 | *notes_buf = vmcore_alloc_buf(size: *notes_sz); |
1056 | if (!*notes_buf) |
1057 | return -ENOMEM; |
1058 | |
1059 | rc = copy_notes_elf32(ehdr_ptr, notes_buf: *notes_buf); |
1060 | if (rc < 0) |
1061 | return rc; |
1062 | |
1063 | /* Prepare merged PT_NOTE program header. */ |
1064 | phdr.p_type = PT_NOTE; |
1065 | phdr.p_flags = 0; |
1066 | note_off = sizeof(Elf32_Ehdr) + |
1067 | (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); |
1068 | phdr.p_offset = roundup(note_off, PAGE_SIZE); |
1069 | phdr.p_vaddr = phdr.p_paddr = 0; |
1070 | phdr.p_filesz = phdr.p_memsz = phdr_sz; |
1071 | phdr.p_align = 4; |
1072 | |
1073 | /* Add merged PT_NOTE program header*/ |
1074 | tmp = elfptr + sizeof(Elf32_Ehdr); |
1075 | memcpy(tmp, &phdr, sizeof(phdr)); |
1076 | tmp += sizeof(phdr); |
1077 | |
1078 | /* Remove unwanted PT_NOTE program headers. */ |
1079 | i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); |
1080 | *elfsz = *elfsz - i; |
1081 | memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); |
1082 | memset(elfptr + *elfsz, 0, i); |
1083 | *elfsz = roundup(*elfsz, PAGE_SIZE); |
1084 | |
1085 | /* Modify e_phnum to reflect merged headers. */ |
1086 | ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; |
1087 | |
1088 | /* Store the size of all notes. We need this to update the note |
1089 | * header when the device dumps will be added. |
1090 | */ |
1091 | elfnotes_orig_sz = phdr.p_memsz; |
1092 | |
1093 | return 0; |
1094 | } |
1095 | |
1096 | /* Add memory chunks represented by program headers to vmcore list. Also update |
1097 | * the new offset fields of exported program headers. */ |
1098 | static int __init (char *elfptr, |
1099 | size_t elfsz, |
1100 | size_t elfnotes_sz, |
1101 | struct list_head *vc_list) |
1102 | { |
1103 | int i; |
1104 | Elf64_Ehdr *ehdr_ptr; |
1105 | Elf64_Phdr *phdr_ptr; |
1106 | loff_t vmcore_off; |
1107 | struct vmcore *new; |
1108 | |
1109 | ehdr_ptr = (Elf64_Ehdr *)elfptr; |
1110 | phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ |
1111 | |
1112 | /* Skip ELF header, program headers and ELF note segment. */ |
1113 | vmcore_off = elfsz + elfnotes_sz; |
1114 | |
1115 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
1116 | u64 paddr, start, end, size; |
1117 | |
1118 | if (phdr_ptr->p_type != PT_LOAD) |
1119 | continue; |
1120 | |
1121 | paddr = phdr_ptr->p_offset; |
1122 | start = rounddown(paddr, PAGE_SIZE); |
1123 | end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); |
1124 | size = end - start; |
1125 | |
1126 | /* Add this contiguous chunk of memory to vmcore list.*/ |
1127 | new = get_new_element(); |
1128 | if (!new) |
1129 | return -ENOMEM; |
1130 | new->paddr = start; |
1131 | new->size = size; |
1132 | list_add_tail(new: &new->list, head: vc_list); |
1133 | |
1134 | /* Update the program header offset. */ |
1135 | phdr_ptr->p_offset = vmcore_off + (paddr - start); |
1136 | vmcore_off = vmcore_off + size; |
1137 | } |
1138 | return 0; |
1139 | } |
1140 | |
1141 | static int __init (char *elfptr, |
1142 | size_t elfsz, |
1143 | size_t elfnotes_sz, |
1144 | struct list_head *vc_list) |
1145 | { |
1146 | int i; |
1147 | Elf32_Ehdr *ehdr_ptr; |
1148 | Elf32_Phdr *phdr_ptr; |
1149 | loff_t vmcore_off; |
1150 | struct vmcore *new; |
1151 | |
1152 | ehdr_ptr = (Elf32_Ehdr *)elfptr; |
1153 | phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ |
1154 | |
1155 | /* Skip ELF header, program headers and ELF note segment. */ |
1156 | vmcore_off = elfsz + elfnotes_sz; |
1157 | |
1158 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
1159 | u64 paddr, start, end, size; |
1160 | |
1161 | if (phdr_ptr->p_type != PT_LOAD) |
1162 | continue; |
1163 | |
1164 | paddr = phdr_ptr->p_offset; |
1165 | start = rounddown(paddr, PAGE_SIZE); |
1166 | end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); |
1167 | size = end - start; |
1168 | |
1169 | /* Add this contiguous chunk of memory to vmcore list.*/ |
1170 | new = get_new_element(); |
1171 | if (!new) |
1172 | return -ENOMEM; |
1173 | new->paddr = start; |
1174 | new->size = size; |
1175 | list_add_tail(new: &new->list, head: vc_list); |
1176 | |
1177 | /* Update the program header offset */ |
1178 | phdr_ptr->p_offset = vmcore_off + (paddr - start); |
1179 | vmcore_off = vmcore_off + size; |
1180 | } |
1181 | return 0; |
1182 | } |
1183 | |
1184 | /* Sets offset fields of vmcore elements. */ |
1185 | static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz, |
1186 | struct list_head *vc_list) |
1187 | { |
1188 | loff_t vmcore_off; |
1189 | struct vmcore *m; |
1190 | |
1191 | /* Skip ELF header, program headers and ELF note segment. */ |
1192 | vmcore_off = elfsz + elfnotes_sz; |
1193 | |
1194 | list_for_each_entry(m, vc_list, list) { |
1195 | m->offset = vmcore_off; |
1196 | vmcore_off += m->size; |
1197 | } |
1198 | } |
1199 | |
1200 | static void free_elfcorebuf(void) |
1201 | { |
1202 | free_pages(addr: (unsigned long)elfcorebuf, order: get_order(size: elfcorebuf_sz_orig)); |
1203 | elfcorebuf = NULL; |
1204 | vfree(addr: elfnotes_buf); |
1205 | elfnotes_buf = NULL; |
1206 | } |
1207 | |
1208 | static int __init (void) |
1209 | { |
1210 | int rc=0; |
1211 | Elf64_Ehdr ehdr; |
1212 | u64 addr; |
1213 | |
1214 | addr = elfcorehdr_addr; |
1215 | |
1216 | /* Read ELF header */ |
1217 | rc = elfcorehdr_read(buf: (char *)&ehdr, count: sizeof(Elf64_Ehdr), ppos: &addr); |
1218 | if (rc < 0) |
1219 | return rc; |
1220 | |
1221 | /* Do some basic Verification. */ |
1222 | if (memcmp(p: ehdr.e_ident, ELFMAG, SELFMAG) != 0 || |
1223 | (ehdr.e_type != ET_CORE) || |
1224 | !vmcore_elf64_check_arch(&ehdr) || |
1225 | ehdr.e_ident[EI_CLASS] != ELFCLASS64 || |
1226 | ehdr.e_ident[EI_VERSION] != EV_CURRENT || |
1227 | ehdr.e_version != EV_CURRENT || |
1228 | ehdr.e_ehsize != sizeof(Elf64_Ehdr) || |
1229 | ehdr.e_phentsize != sizeof(Elf64_Phdr) || |
1230 | ehdr.e_phnum == 0) { |
1231 | pr_warn("Warning: Core image elf header is not sane\n" ); |
1232 | return -EINVAL; |
1233 | } |
1234 | |
1235 | /* Read in all elf headers. */ |
1236 | elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) + |
1237 | ehdr.e_phnum * sizeof(Elf64_Phdr); |
1238 | elfcorebuf_sz = elfcorebuf_sz_orig; |
1239 | elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, |
1240 | order: get_order(size: elfcorebuf_sz_orig)); |
1241 | if (!elfcorebuf) |
1242 | return -ENOMEM; |
1243 | addr = elfcorehdr_addr; |
1244 | rc = elfcorehdr_read(buf: elfcorebuf, count: elfcorebuf_sz_orig, ppos: &addr); |
1245 | if (rc < 0) |
1246 | goto fail; |
1247 | |
1248 | /* Merge all PT_NOTE headers into one. */ |
1249 | rc = merge_note_headers_elf64(elfptr: elfcorebuf, elfsz: &elfcorebuf_sz, |
1250 | notes_buf: &elfnotes_buf, notes_sz: &elfnotes_sz); |
1251 | if (rc) |
1252 | goto fail; |
1253 | rc = process_ptload_program_headers_elf64(elfptr: elfcorebuf, elfsz: elfcorebuf_sz, |
1254 | elfnotes_sz, vc_list: &vmcore_list); |
1255 | if (rc) |
1256 | goto fail; |
1257 | set_vmcore_list_offsets(elfsz: elfcorebuf_sz, elfnotes_sz, vc_list: &vmcore_list); |
1258 | return 0; |
1259 | fail: |
1260 | free_elfcorebuf(); |
1261 | return rc; |
1262 | } |
1263 | |
1264 | static int __init (void) |
1265 | { |
1266 | int rc=0; |
1267 | Elf32_Ehdr ehdr; |
1268 | u64 addr; |
1269 | |
1270 | addr = elfcorehdr_addr; |
1271 | |
1272 | /* Read ELF header */ |
1273 | rc = elfcorehdr_read(buf: (char *)&ehdr, count: sizeof(Elf32_Ehdr), ppos: &addr); |
1274 | if (rc < 0) |
1275 | return rc; |
1276 | |
1277 | /* Do some basic Verification. */ |
1278 | if (memcmp(p: ehdr.e_ident, ELFMAG, SELFMAG) != 0 || |
1279 | (ehdr.e_type != ET_CORE) || |
1280 | !vmcore_elf32_check_arch(&ehdr) || |
1281 | ehdr.e_ident[EI_CLASS] != ELFCLASS32|| |
1282 | ehdr.e_ident[EI_VERSION] != EV_CURRENT || |
1283 | ehdr.e_version != EV_CURRENT || |
1284 | ehdr.e_ehsize != sizeof(Elf32_Ehdr) || |
1285 | ehdr.e_phentsize != sizeof(Elf32_Phdr) || |
1286 | ehdr.e_phnum == 0) { |
1287 | pr_warn("Warning: Core image elf header is not sane\n" ); |
1288 | return -EINVAL; |
1289 | } |
1290 | |
1291 | /* Read in all elf headers. */ |
1292 | elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); |
1293 | elfcorebuf_sz = elfcorebuf_sz_orig; |
1294 | elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, |
1295 | order: get_order(size: elfcorebuf_sz_orig)); |
1296 | if (!elfcorebuf) |
1297 | return -ENOMEM; |
1298 | addr = elfcorehdr_addr; |
1299 | rc = elfcorehdr_read(buf: elfcorebuf, count: elfcorebuf_sz_orig, ppos: &addr); |
1300 | if (rc < 0) |
1301 | goto fail; |
1302 | |
1303 | /* Merge all PT_NOTE headers into one. */ |
1304 | rc = merge_note_headers_elf32(elfptr: elfcorebuf, elfsz: &elfcorebuf_sz, |
1305 | notes_buf: &elfnotes_buf, notes_sz: &elfnotes_sz); |
1306 | if (rc) |
1307 | goto fail; |
1308 | rc = process_ptload_program_headers_elf32(elfptr: elfcorebuf, elfsz: elfcorebuf_sz, |
1309 | elfnotes_sz, vc_list: &vmcore_list); |
1310 | if (rc) |
1311 | goto fail; |
1312 | set_vmcore_list_offsets(elfsz: elfcorebuf_sz, elfnotes_sz, vc_list: &vmcore_list); |
1313 | return 0; |
1314 | fail: |
1315 | free_elfcorebuf(); |
1316 | return rc; |
1317 | } |
1318 | |
1319 | static int __init (void) |
1320 | { |
1321 | unsigned char e_ident[EI_NIDENT]; |
1322 | u64 addr; |
1323 | int rc=0; |
1324 | |
1325 | addr = elfcorehdr_addr; |
1326 | rc = elfcorehdr_read(buf: e_ident, EI_NIDENT, ppos: &addr); |
1327 | if (rc < 0) |
1328 | return rc; |
1329 | if (memcmp(p: e_ident, ELFMAG, SELFMAG) != 0) { |
1330 | pr_warn("Warning: Core image elf header not found\n" ); |
1331 | return -EINVAL; |
1332 | } |
1333 | |
1334 | if (e_ident[EI_CLASS] == ELFCLASS64) { |
1335 | rc = parse_crash_elf64_headers(); |
1336 | if (rc) |
1337 | return rc; |
1338 | } else if (e_ident[EI_CLASS] == ELFCLASS32) { |
1339 | rc = parse_crash_elf32_headers(); |
1340 | if (rc) |
1341 | return rc; |
1342 | } else { |
1343 | pr_warn("Warning: Core image elf header is not sane\n" ); |
1344 | return -EINVAL; |
1345 | } |
1346 | |
1347 | /* Determine vmcore size. */ |
1348 | vmcore_size = get_vmcore_size(elfsz: elfcorebuf_sz, elfnotesegsz: elfnotes_sz, |
1349 | vc_list: &vmcore_list); |
1350 | |
1351 | return 0; |
1352 | } |
1353 | |
1354 | #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP |
1355 | /** |
1356 | * vmcoredd_write_header - Write vmcore device dump header at the |
1357 | * beginning of the dump's buffer. |
1358 | * @buf: Output buffer where the note is written |
1359 | * @data: Dump info |
1360 | * @size: Size of the dump |
1361 | * |
1362 | * Fills beginning of the dump's buffer with vmcore device dump header. |
1363 | */ |
1364 | static void (void *buf, struct vmcoredd_data *data, |
1365 | u32 size) |
1366 | { |
1367 | struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf; |
1368 | |
1369 | vdd_hdr->n_namesz = sizeof(vdd_hdr->name); |
1370 | vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name); |
1371 | vdd_hdr->n_type = NT_VMCOREDD; |
1372 | |
1373 | strncpy(p: (char *)vdd_hdr->name, VMCOREDD_NOTE_NAME, |
1374 | size: sizeof(vdd_hdr->name)); |
1375 | memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name)); |
1376 | } |
1377 | |
1378 | /** |
1379 | * vmcoredd_update_program_headers - Update all ELF program headers |
1380 | * @elfptr: Pointer to elf header |
1381 | * @elfnotesz: Size of elf notes aligned to page size |
1382 | * @vmcoreddsz: Size of device dumps to be added to elf note header |
1383 | * |
1384 | * Determine type of ELF header (Elf64 or Elf32) and update the elf note size. |
1385 | * Also update the offsets of all the program headers after the elf note header. |
1386 | */ |
1387 | static void (char *elfptr, size_t elfnotesz, |
1388 | size_t vmcoreddsz) |
1389 | { |
1390 | unsigned char *e_ident = (unsigned char *)elfptr; |
1391 | u64 start, end, size; |
1392 | loff_t vmcore_off; |
1393 | u32 i; |
1394 | |
1395 | vmcore_off = elfcorebuf_sz + elfnotesz; |
1396 | |
1397 | if (e_ident[EI_CLASS] == ELFCLASS64) { |
1398 | Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr; |
1399 | Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr)); |
1400 | |
1401 | /* Update all program headers */ |
1402 | for (i = 0; i < ehdr->e_phnum; i++, phdr++) { |
1403 | if (phdr->p_type == PT_NOTE) { |
1404 | /* Update note size */ |
1405 | phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; |
1406 | phdr->p_filesz = phdr->p_memsz; |
1407 | continue; |
1408 | } |
1409 | |
1410 | start = rounddown(phdr->p_offset, PAGE_SIZE); |
1411 | end = roundup(phdr->p_offset + phdr->p_memsz, |
1412 | PAGE_SIZE); |
1413 | size = end - start; |
1414 | phdr->p_offset = vmcore_off + (phdr->p_offset - start); |
1415 | vmcore_off += size; |
1416 | } |
1417 | } else { |
1418 | Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr; |
1419 | Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr)); |
1420 | |
1421 | /* Update all program headers */ |
1422 | for (i = 0; i < ehdr->e_phnum; i++, phdr++) { |
1423 | if (phdr->p_type == PT_NOTE) { |
1424 | /* Update note size */ |
1425 | phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz; |
1426 | phdr->p_filesz = phdr->p_memsz; |
1427 | continue; |
1428 | } |
1429 | |
1430 | start = rounddown(phdr->p_offset, PAGE_SIZE); |
1431 | end = roundup(phdr->p_offset + phdr->p_memsz, |
1432 | PAGE_SIZE); |
1433 | size = end - start; |
1434 | phdr->p_offset = vmcore_off + (phdr->p_offset - start); |
1435 | vmcore_off += size; |
1436 | } |
1437 | } |
1438 | } |
1439 | |
1440 | /** |
1441 | * vmcoredd_update_size - Update the total size of the device dumps and update |
1442 | * ELF header |
1443 | * @dump_size: Size of the current device dump to be added to total size |
1444 | * |
1445 | * Update the total size of all the device dumps and update the ELF program |
1446 | * headers. Calculate the new offsets for the vmcore list and update the |
1447 | * total vmcore size. |
1448 | */ |
1449 | static void vmcoredd_update_size(size_t dump_size) |
1450 | { |
1451 | vmcoredd_orig_sz += dump_size; |
1452 | elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz; |
1453 | vmcoredd_update_program_headers(elfptr: elfcorebuf, elfnotesz: elfnotes_sz, |
1454 | vmcoreddsz: vmcoredd_orig_sz); |
1455 | |
1456 | /* Update vmcore list offsets */ |
1457 | set_vmcore_list_offsets(elfsz: elfcorebuf_sz, elfnotes_sz, vc_list: &vmcore_list); |
1458 | |
1459 | vmcore_size = get_vmcore_size(elfsz: elfcorebuf_sz, elfnotesegsz: elfnotes_sz, |
1460 | vc_list: &vmcore_list); |
1461 | proc_vmcore->size = vmcore_size; |
1462 | } |
1463 | |
1464 | /** |
1465 | * vmcore_add_device_dump - Add a buffer containing device dump to vmcore |
1466 | * @data: dump info. |
1467 | * |
1468 | * Allocate a buffer and invoke the calling driver's dump collect routine. |
1469 | * Write ELF note at the beginning of the buffer to indicate vmcore device |
1470 | * dump and add the dump to global list. |
1471 | */ |
1472 | int vmcore_add_device_dump(struct vmcoredd_data *data) |
1473 | { |
1474 | struct vmcoredd_node *dump; |
1475 | void *buf = NULL; |
1476 | size_t data_size; |
1477 | int ret; |
1478 | |
1479 | if (vmcoredd_disabled) { |
1480 | pr_err_once("Device dump is disabled\n" ); |
1481 | return -EINVAL; |
1482 | } |
1483 | |
1484 | if (!data || !strlen(data->dump_name) || |
1485 | !data->vmcoredd_callback || !data->size) |
1486 | return -EINVAL; |
1487 | |
1488 | dump = vzalloc(size: sizeof(*dump)); |
1489 | if (!dump) { |
1490 | ret = -ENOMEM; |
1491 | goto out_err; |
1492 | } |
1493 | |
1494 | /* Keep size of the buffer page aligned so that it can be mmaped */ |
1495 | data_size = roundup(sizeof(struct vmcoredd_header) + data->size, |
1496 | PAGE_SIZE); |
1497 | |
1498 | /* Allocate buffer for driver's to write their dumps */ |
1499 | buf = vmcore_alloc_buf(size: data_size); |
1500 | if (!buf) { |
1501 | ret = -ENOMEM; |
1502 | goto out_err; |
1503 | } |
1504 | |
1505 | vmcoredd_write_header(buf, data, size: data_size - |
1506 | sizeof(struct vmcoredd_header)); |
1507 | |
1508 | /* Invoke the driver's dump collection routing */ |
1509 | ret = data->vmcoredd_callback(data, buf + |
1510 | sizeof(struct vmcoredd_header)); |
1511 | if (ret) |
1512 | goto out_err; |
1513 | |
1514 | dump->buf = buf; |
1515 | dump->size = data_size; |
1516 | |
1517 | /* Add the dump to driver sysfs list */ |
1518 | mutex_lock(&vmcoredd_mutex); |
1519 | list_add_tail(new: &dump->list, head: &vmcoredd_list); |
1520 | mutex_unlock(lock: &vmcoredd_mutex); |
1521 | |
1522 | vmcoredd_update_size(dump_size: data_size); |
1523 | return 0; |
1524 | |
1525 | out_err: |
1526 | vfree(addr: buf); |
1527 | vfree(addr: dump); |
1528 | |
1529 | return ret; |
1530 | } |
1531 | EXPORT_SYMBOL(vmcore_add_device_dump); |
1532 | #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ |
1533 | |
1534 | /* Free all dumps in vmcore device dump list */ |
1535 | static void vmcore_free_device_dumps(void) |
1536 | { |
1537 | #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP |
1538 | mutex_lock(&vmcoredd_mutex); |
1539 | while (!list_empty(head: &vmcoredd_list)) { |
1540 | struct vmcoredd_node *dump; |
1541 | |
1542 | dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node, |
1543 | list); |
1544 | list_del(entry: &dump->list); |
1545 | vfree(addr: dump->buf); |
1546 | vfree(addr: dump); |
1547 | } |
1548 | mutex_unlock(lock: &vmcoredd_mutex); |
1549 | #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ |
1550 | } |
1551 | |
1552 | /* Init function for vmcore module. */ |
1553 | static int __init vmcore_init(void) |
1554 | { |
1555 | int rc = 0; |
1556 | |
1557 | /* Allow architectures to allocate ELF header in 2nd kernel */ |
1558 | rc = elfcorehdr_alloc(addr: &elfcorehdr_addr, size: &elfcorehdr_size); |
1559 | if (rc) |
1560 | return rc; |
1561 | /* |
1562 | * If elfcorehdr= has been passed in cmdline or created in 2nd kernel, |
1563 | * then capture the dump. |
1564 | */ |
1565 | if (!(is_vmcore_usable())) |
1566 | return rc; |
1567 | rc = parse_crash_elf_headers(); |
1568 | if (rc) { |
1569 | elfcorehdr_free(addr: elfcorehdr_addr); |
1570 | pr_warn("Kdump: vmcore not initialized\n" ); |
1571 | return rc; |
1572 | } |
1573 | elfcorehdr_free(addr: elfcorehdr_addr); |
1574 | elfcorehdr_addr = ELFCORE_ADDR_ERR; |
1575 | |
1576 | proc_vmcore = proc_create(name: "vmcore" , S_IRUSR, NULL, proc_ops: &vmcore_proc_ops); |
1577 | if (proc_vmcore) |
1578 | proc_vmcore->size = vmcore_size; |
1579 | return 0; |
1580 | } |
1581 | fs_initcall(vmcore_init); |
1582 | |
1583 | /* Cleanup function for vmcore module. */ |
1584 | void vmcore_cleanup(void) |
1585 | { |
1586 | if (proc_vmcore) { |
1587 | proc_remove(proc_vmcore); |
1588 | proc_vmcore = NULL; |
1589 | } |
1590 | |
1591 | /* clear the vmcore list. */ |
1592 | while (!list_empty(head: &vmcore_list)) { |
1593 | struct vmcore *m; |
1594 | |
1595 | m = list_first_entry(&vmcore_list, struct vmcore, list); |
1596 | list_del(entry: &m->list); |
1597 | kfree(objp: m); |
1598 | } |
1599 | free_elfcorebuf(); |
1600 | |
1601 | /* clear vmcore device dump list */ |
1602 | vmcore_free_device_dumps(); |
1603 | } |
1604 | |