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#define pr_fmt(fmt) "vmcore: " fmt
12
13#include <linux/mm.h>
14#include <linux/kcore.h>
15#include <linux/user.h>
16#include <linux/elf.h>
17#include <linux/elfcore.h>
18#include <linux/export.h>
19#include <linux/slab.h>
20#include <linux/highmem.h>
21#include <linux/printk.h>
22#include <linux/memblock.h>
23#include <linux/init.h>
24#include <linux/crash_dump.h>
25#include <linux/list.h>
26#include <linux/moduleparam.h>
27#include <linux/mutex.h>
28#include <linux/vmalloc.h>
29#include <linux/pagemap.h>
30#include <linux/uio.h>
31#include <linux/cc_platform.h>
32#include <asm/io.h>
33#include "internal.h"
34
35/* List representing chunks of contiguous memory areas and their offsets in
36 * vmcore file.
37 */
38static LIST_HEAD(vmcore_list);
39
40/* Stores the pointer to the buffer containing kernel elf core headers. */
41static char *elfcorebuf;
42static size_t elfcorebuf_sz;
43static size_t elfcorebuf_sz_orig;
44
45static char *elfnotes_buf;
46static size_t elfnotes_sz;
47/* Size of all notes minus the device dump notes */
48static size_t elfnotes_orig_sz;
49
50/* Total size of vmcore file. */
51static u64 vmcore_size;
52
53static struct proc_dir_entry *proc_vmcore;
54
55#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
56struct vmcoredd_node {
57 struct list_head list; /* List of dumps */
58 void *buf; /* Buffer containing device's dump */
59 unsigned int size; /* Size of the buffer */
60};
61
62/* Device Dump list and mutex to synchronize access to list */
63static LIST_HEAD(vmcoredd_list);
64
65static bool vmcoredd_disabled;
66core_param(novmcoredd, vmcoredd_disabled, bool, 0);
67#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
68
69/* Device Dump Size */
70static size_t vmcoredd_orig_sz;
71
72static DEFINE_MUTEX(vmcore_mutex);
73
74DEFINE_STATIC_SRCU(vmcore_cb_srcu);
75/* List of registered vmcore callbacks. */
76static LIST_HEAD(vmcore_cb_list);
77/* Whether the vmcore has been opened once. */
78static bool vmcore_opened;
79/* Whether the vmcore is currently open. */
80static unsigned int vmcore_open;
81
82static void vmcore_process_device_ram(struct vmcore_cb *cb);
83
84void register_vmcore_cb(struct vmcore_cb *cb)
85{
86 INIT_LIST_HEAD(list: &cb->next);
87 mutex_lock(&vmcore_mutex);
88 list_add_tail(new: &cb->next, head: &vmcore_cb_list);
89 /*
90 * Registering a vmcore callback after the vmcore was opened is
91 * very unusual (e.g., manual driver loading).
92 */
93 if (vmcore_opened)
94 pr_warn_once("Unexpected vmcore callback registration\n");
95 if (!vmcore_open && cb->get_device_ram)
96 vmcore_process_device_ram(cb);
97 mutex_unlock(lock: &vmcore_mutex);
98}
99EXPORT_SYMBOL_GPL(register_vmcore_cb);
100
101void unregister_vmcore_cb(struct vmcore_cb *cb)
102{
103 mutex_lock(&vmcore_mutex);
104 list_del_rcu(entry: &cb->next);
105 /*
106 * Unregistering a vmcore callback after the vmcore was opened is
107 * very unusual (e.g., forced driver removal), but we cannot stop
108 * unregistering.
109 */
110 if (vmcore_opened)
111 pr_warn_once("Unexpected vmcore callback unregistration\n");
112 mutex_unlock(lock: &vmcore_mutex);
113
114 synchronize_srcu(ssp: &vmcore_cb_srcu);
115}
116EXPORT_SYMBOL_GPL(unregister_vmcore_cb);
117
118static bool pfn_is_ram(unsigned long pfn)
119{
120 struct vmcore_cb *cb;
121 bool ret = true;
122
123 list_for_each_entry_srcu(cb, &vmcore_cb_list, next,
124 srcu_read_lock_held(&vmcore_cb_srcu)) {
125 if (unlikely(!cb->pfn_is_ram))
126 continue;
127 ret = cb->pfn_is_ram(cb, pfn);
128 if (!ret)
129 break;
130 }
131
132 return ret;
133}
134
135static int open_vmcore(struct inode *inode, struct file *file)
136{
137 mutex_lock(&vmcore_mutex);
138 vmcore_opened = true;
139 if (vmcore_open + 1 == 0) {
140 mutex_unlock(lock: &vmcore_mutex);
141 return -EBUSY;
142 }
143 vmcore_open++;
144 mutex_unlock(lock: &vmcore_mutex);
145
146 return 0;
147}
148
149static int release_vmcore(struct inode *inode, struct file *file)
150{
151 mutex_lock(&vmcore_mutex);
152 vmcore_open--;
153 mutex_unlock(lock: &vmcore_mutex);
154
155 return 0;
156}
157
158/* Reads a page from the oldmem device from given offset. */
159ssize_t read_from_oldmem(struct iov_iter *iter, size_t count,
160 u64 *ppos, bool encrypted)
161{
162 unsigned long pfn, offset;
163 ssize_t nr_bytes;
164 ssize_t read = 0, tmp;
165 int idx;
166
167 if (!count)
168 return 0;
169
170 offset = (unsigned long)(*ppos % PAGE_SIZE);
171 pfn = (unsigned long)(*ppos / PAGE_SIZE);
172
173 idx = srcu_read_lock(ssp: &vmcore_cb_srcu);
174 do {
175 if (count > (PAGE_SIZE - offset))
176 nr_bytes = PAGE_SIZE - offset;
177 else
178 nr_bytes = count;
179
180 /* If pfn is not ram, return zeros for sparse dump files */
181 if (!pfn_is_ram(pfn)) {
182 tmp = iov_iter_zero(bytes: nr_bytes, iter);
183 } else {
184 if (encrypted)
185 tmp = copy_oldmem_page_encrypted(iter, pfn,
186 csize: nr_bytes,
187 offset);
188 else
189 tmp = copy_oldmem_page(i: iter, pfn, csize: nr_bytes,
190 offset);
191 }
192 if (tmp < nr_bytes) {
193 srcu_read_unlock(ssp: &vmcore_cb_srcu, idx);
194 return -EFAULT;
195 }
196
197 *ppos += nr_bytes;
198 count -= nr_bytes;
199 read += nr_bytes;
200 ++pfn;
201 offset = 0;
202 } while (count);
203 srcu_read_unlock(ssp: &vmcore_cb_srcu, idx);
204
205 return read;
206}
207
208/*
209 * Architectures may override this function to allocate ELF header in 2nd kernel
210 */
211int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
212{
213 return 0;
214}
215
216/*
217 * Architectures may override this function to free header
218 */
219void __weak elfcorehdr_free(unsigned long long addr)
220{}
221
222/*
223 * Architectures may override this function to read from ELF header
224 */
225ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
226{
227 struct kvec kvec = { .iov_base = buf, .iov_len = count };
228 struct iov_iter iter;
229
230 iov_iter_kvec(i: &iter, ITER_DEST, kvec: &kvec, nr_segs: 1, count);
231
232 return read_from_oldmem(iter: &iter, count, ppos, encrypted: false);
233}
234
235/*
236 * Architectures may override this function to read from notes sections
237 */
238ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
239{
240 struct kvec kvec = { .iov_base = buf, .iov_len = count };
241 struct iov_iter iter;
242
243 iov_iter_kvec(i: &iter, ITER_DEST, kvec: &kvec, nr_segs: 1, count);
244
245 return read_from_oldmem(iter: &iter, count, ppos,
246 encrypted: cc_platform_has(attr: CC_ATTR_MEM_ENCRYPT));
247}
248
249/*
250 * Architectures may override this function to map oldmem
251 */
252int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
253 unsigned long from, unsigned long pfn,
254 unsigned long size, pgprot_t prot)
255{
256 prot = pgprot_encrypted(prot);
257 return remap_pfn_range(vma, addr: from, pfn, size, pgprot: prot);
258}
259
260/*
261 * Architectures which support memory encryption override this.
262 */
263ssize_t __weak copy_oldmem_page_encrypted(struct iov_iter *iter,
264 unsigned long pfn, size_t csize, unsigned long offset)
265{
266 return copy_oldmem_page(i: iter, pfn, csize, offset);
267}
268
269#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
270static int vmcoredd_copy_dumps(struct iov_iter *iter, u64 start, size_t size)
271{
272 struct vmcoredd_node *dump;
273 u64 offset = 0;
274 size_t tsz;
275 char *buf;
276
277 list_for_each_entry(dump, &vmcoredd_list, list) {
278 if (start < offset + dump->size) {
279 tsz = min(offset + (u64)dump->size - start, (u64)size);
280 buf = dump->buf + start - offset;
281 if (copy_to_iter(addr: buf, bytes: tsz, i: iter) < tsz)
282 return -EFAULT;
283
284 size -= tsz;
285 start += tsz;
286
287 /* Leave now if buffer filled already */
288 if (!size)
289 return 0;
290 }
291 offset += dump->size;
292 }
293
294 return 0;
295}
296
297#ifdef CONFIG_MMU
298static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst,
299 u64 start, size_t size)
300{
301 struct vmcoredd_node *dump;
302 u64 offset = 0;
303 size_t tsz;
304 char *buf;
305
306 list_for_each_entry(dump, &vmcoredd_list, list) {
307 if (start < offset + dump->size) {
308 tsz = min(offset + (u64)dump->size - start, (u64)size);
309 buf = dump->buf + start - offset;
310 if (remap_vmalloc_range_partial(vma, uaddr: dst, kaddr: buf, pgoff: 0,
311 size: tsz))
312 return -EFAULT;
313
314 size -= tsz;
315 start += tsz;
316 dst += tsz;
317
318 /* Leave now if buffer filled already */
319 if (!size)
320 return 0;
321 }
322 offset += dump->size;
323 }
324
325 return 0;
326}
327#endif /* CONFIG_MMU */
328#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
329
330/* Read from the ELF header and then the crash dump. On error, negative value is
331 * returned otherwise number of bytes read are returned.
332 */
333static ssize_t __read_vmcore(struct iov_iter *iter, loff_t *fpos)
334{
335 struct vmcore_range *m = NULL;
336 ssize_t acc = 0, tmp;
337 size_t tsz;
338 u64 start;
339
340 if (!iov_iter_count(i: iter) || *fpos >= vmcore_size)
341 return 0;
342
343 iov_iter_truncate(i: iter, count: vmcore_size - *fpos);
344
345 /* Read ELF core header */
346 if (*fpos < elfcorebuf_sz) {
347 tsz = min(elfcorebuf_sz - (size_t)*fpos, iov_iter_count(iter));
348 if (copy_to_iter(addr: elfcorebuf + *fpos, bytes: tsz, i: iter) < tsz)
349 return -EFAULT;
350 *fpos += tsz;
351 acc += tsz;
352
353 /* leave now if filled buffer already */
354 if (!iov_iter_count(i: iter))
355 return acc;
356 }
357
358 /* Read ELF note segment */
359 if (*fpos < elfcorebuf_sz + elfnotes_sz) {
360 void *kaddr;
361
362 /* We add device dumps before other elf notes because the
363 * other elf notes may not fill the elf notes buffer
364 * completely and we will end up with zero-filled data
365 * between the elf notes and the device dumps. Tools will
366 * then try to decode this zero-filled data as valid notes
367 * and we don't want that. Hence, adding device dumps before
368 * the other elf notes ensure that zero-filled data can be
369 * avoided.
370 */
371#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
372 /* Read device dumps */
373 if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) {
374 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
375 (size_t)*fpos, iov_iter_count(iter));
376 start = *fpos - elfcorebuf_sz;
377 if (vmcoredd_copy_dumps(iter, start, size: 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#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
388
389 /* Read remaining elf notes */
390 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos,
391 iov_iter_count(iter));
392 kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz;
393 if (copy_to_iter(addr: kaddr, bytes: tsz, i: iter) < tsz)
394 return -EFAULT;
395
396 *fpos += tsz;
397 acc += tsz;
398
399 /* leave now if filled buffer already */
400 if (!iov_iter_count(i: iter))
401 return acc;
402
403 cond_resched();
404 }
405
406 list_for_each_entry(m, &vmcore_list, list) {
407 if (*fpos < m->offset + m->size) {
408 tsz = (size_t)min_t(unsigned long long,
409 m->offset + m->size - *fpos,
410 iov_iter_count(iter));
411 start = m->paddr + *fpos - m->offset;
412 tmp = read_from_oldmem(iter, count: tsz, ppos: &start,
413 encrypted: cc_platform_has(attr: CC_ATTR_MEM_ENCRYPT));
414 if (tmp < 0)
415 return tmp;
416 *fpos += tsz;
417 acc += tsz;
418
419 /* leave now if filled buffer already */
420 if (!iov_iter_count(i: iter))
421 return acc;
422 }
423
424 cond_resched();
425 }
426
427 return acc;
428}
429
430static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter)
431{
432 return __read_vmcore(iter, fpos: &iocb->ki_pos);
433}
434
435/**
436 * vmcore_alloc_buf - allocate buffer in vmalloc memory
437 * @size: size of buffer
438 *
439 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
440 * the buffer to user-space by means of remap_vmalloc_range().
441 *
442 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
443 * disabled and there's no need to allow users to mmap the buffer.
444 */
445static inline char *vmcore_alloc_buf(size_t size)
446{
447#ifdef CONFIG_MMU
448 return vmalloc_user(size);
449#else
450 return vzalloc(size);
451#endif
452}
453
454/*
455 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
456 * essential for mmap_vmcore() in order to map physically
457 * non-contiguous objects (ELF header, ELF note segment and memory
458 * regions in the 1st kernel pointed to by PT_LOAD entries) into
459 * virtually contiguous user-space in ELF layout.
460 */
461#ifdef CONFIG_MMU
462
463/*
464 * The vmcore fault handler uses the page cache and fills data using the
465 * standard __read_vmcore() function.
466 *
467 * On s390 the fault handler is used for memory regions that can't be mapped
468 * directly with remap_pfn_range().
469 */
470static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
471{
472#ifdef CONFIG_S390
473 struct address_space *mapping = vmf->vma->vm_file->f_mapping;
474 pgoff_t index = vmf->pgoff;
475 struct iov_iter iter;
476 struct kvec kvec;
477 struct page *page;
478 loff_t offset;
479 int rc;
480
481 page = find_or_create_page(mapping, index, GFP_KERNEL);
482 if (!page)
483 return VM_FAULT_OOM;
484 if (!PageUptodate(page)) {
485 offset = (loff_t) index << PAGE_SHIFT;
486 kvec.iov_base = page_address(page);
487 kvec.iov_len = PAGE_SIZE;
488 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE);
489
490 rc = __read_vmcore(&iter, &offset);
491 if (rc < 0) {
492 unlock_page(page);
493 put_page(page);
494 return vmf_error(rc);
495 }
496 SetPageUptodate(page);
497 }
498 unlock_page(page);
499 vmf->page = page;
500 return 0;
501#else
502 return VM_FAULT_SIGBUS;
503#endif
504}
505
506static const struct vm_operations_struct vmcore_mmap_ops = {
507 .fault = mmap_vmcore_fault,
508};
509
510/*
511 * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages
512 * reported as not being ram with the zero page.
513 *
514 * @vma: vm_area_struct describing requested mapping
515 * @from: start remapping from
516 * @pfn: page frame number to start remapping to
517 * @size: remapping size
518 * @prot: protection bits
519 *
520 * Returns zero on success, -EAGAIN on failure.
521 */
522static int remap_oldmem_pfn_checked(struct vm_area_struct *vma,
523 unsigned long from, unsigned long pfn,
524 unsigned long size, pgprot_t prot)
525{
526 unsigned long map_size;
527 unsigned long pos_start, pos_end, pos;
528 unsigned long zeropage_pfn = my_zero_pfn(addr: 0);
529 size_t len = 0;
530
531 pos_start = pfn;
532 pos_end = pfn + (size >> PAGE_SHIFT);
533
534 for (pos = pos_start; pos < pos_end; ++pos) {
535 if (!pfn_is_ram(pfn: pos)) {
536 /*
537 * We hit a page which is not ram. Remap the continuous
538 * region between pos_start and pos-1 and replace
539 * the non-ram page at pos with the zero page.
540 */
541 if (pos > pos_start) {
542 /* Remap continuous region */
543 map_size = (pos - pos_start) << PAGE_SHIFT;
544 if (remap_oldmem_pfn_range(vma, from: from + len,
545 pfn: pos_start, size: map_size,
546 prot))
547 goto fail;
548 len += map_size;
549 }
550 /* Remap the zero page */
551 if (remap_oldmem_pfn_range(vma, from: from + len,
552 pfn: zeropage_pfn,
553 PAGE_SIZE, prot))
554 goto fail;
555 len += PAGE_SIZE;
556 pos_start = pos + 1;
557 }
558 }
559 if (pos > pos_start) {
560 /* Remap the rest */
561 map_size = (pos - pos_start) << PAGE_SHIFT;
562 if (remap_oldmem_pfn_range(vma, from: from + len, pfn: pos_start,
563 size: map_size, prot))
564 goto fail;
565 }
566 return 0;
567fail:
568 do_munmap(vma->vm_mm, from, len, NULL);
569 return -EAGAIN;
570}
571
572static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,
573 unsigned long from, unsigned long pfn,
574 unsigned long size, pgprot_t prot)
575{
576 int ret, idx;
577
578 /*
579 * Check if a callback was registered to avoid looping over all
580 * pages without a reason.
581 */
582 idx = srcu_read_lock(ssp: &vmcore_cb_srcu);
583 if (!list_empty(head: &vmcore_cb_list))
584 ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
585 else
586 ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot);
587 srcu_read_unlock(ssp: &vmcore_cb_srcu, idx);
588 return ret;
589}
590
591static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
592{
593 size_t size = vma->vm_end - vma->vm_start;
594 u64 start, end, len, tsz;
595 struct vmcore_range *m;
596
597 start = (u64)vma->vm_pgoff << PAGE_SHIFT;
598 end = start + size;
599
600 if (size > vmcore_size || end > vmcore_size)
601 return -EINVAL;
602
603 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
604 return -EPERM;
605
606 vm_flags_mod(vma, VM_MIXEDMAP, VM_MAYWRITE | VM_MAYEXEC);
607 vma->vm_ops = &vmcore_mmap_ops;
608
609 len = 0;
610
611 if (start < elfcorebuf_sz) {
612 u64 pfn;
613
614 tsz = min(elfcorebuf_sz - (size_t)start, size);
615 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
616 if (remap_pfn_range(vma, addr: vma->vm_start, pfn, size: tsz,
617 pgprot: vma->vm_page_prot))
618 return -EAGAIN;
619 size -= tsz;
620 start += tsz;
621 len += tsz;
622
623 if (size == 0)
624 return 0;
625 }
626
627 if (start < elfcorebuf_sz + elfnotes_sz) {
628 void *kaddr;
629
630 /* We add device dumps before other elf notes because the
631 * other elf notes may not fill the elf notes buffer
632 * completely and we will end up with zero-filled data
633 * between the elf notes and the device dumps. Tools will
634 * then try to decode this zero-filled data as valid notes
635 * and we don't want that. Hence, adding device dumps before
636 * the other elf notes ensure that zero-filled data can be
637 * avoided. This also ensures that the device dumps and
638 * other elf notes can be properly mmaped at page aligned
639 * address.
640 */
641#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
642 /* Read device dumps */
643 if (start < elfcorebuf_sz + vmcoredd_orig_sz) {
644 u64 start_off;
645
646 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
647 (size_t)start, size);
648 start_off = start - elfcorebuf_sz;
649 if (vmcoredd_mmap_dumps(vma, dst: vma->vm_start + len,
650 start: start_off, size: tsz))
651 goto fail;
652
653 size -= tsz;
654 start += tsz;
655 len += tsz;
656
657 /* leave now if filled buffer already */
658 if (!size)
659 return 0;
660 }
661#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
662
663 /* Read remaining elf notes */
664 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
665 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz;
666 if (remap_vmalloc_range_partial(vma, uaddr: vma->vm_start + len,
667 kaddr, pgoff: 0, size: tsz))
668 goto fail;
669
670 size -= tsz;
671 start += tsz;
672 len += tsz;
673
674 if (size == 0)
675 return 0;
676 }
677
678 list_for_each_entry(m, &vmcore_list, list) {
679 if (start < m->offset + m->size) {
680 u64 paddr = 0;
681
682 tsz = (size_t)min_t(unsigned long long,
683 m->offset + m->size - start, size);
684 paddr = m->paddr + start - m->offset;
685 if (vmcore_remap_oldmem_pfn(vma, from: vma->vm_start + len,
686 pfn: paddr >> PAGE_SHIFT, size: tsz,
687 prot: vma->vm_page_prot))
688 goto fail;
689 size -= tsz;
690 start += tsz;
691 len += tsz;
692
693 if (size == 0)
694 return 0;
695 }
696 }
697
698 return 0;
699fail:
700 do_munmap(vma->vm_mm, vma->vm_start, len, NULL);
701 return -EAGAIN;
702}
703#else
704static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
705{
706 return -ENOSYS;
707}
708#endif
709
710static const struct proc_ops vmcore_proc_ops = {
711 .proc_open = open_vmcore,
712 .proc_release = release_vmcore,
713 .proc_read_iter = read_vmcore,
714 .proc_lseek = default_llseek,
715 .proc_mmap = mmap_vmcore,
716};
717
718static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
719 struct list_head *vc_list)
720{
721 struct vmcore_range *m;
722 u64 size;
723
724 size = elfsz + elfnotesegsz;
725 list_for_each_entry(m, vc_list, list) {
726 size += m->size;
727 }
728 return size;
729}
730
731/**
732 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
733 *
734 * @ehdr_ptr: ELF header
735 *
736 * This function updates p_memsz member of each PT_NOTE entry in the
737 * program header table pointed to by @ehdr_ptr to real size of ELF
738 * note segment.
739 */
740static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
741{
742 int i, rc=0;
743 Elf64_Phdr *phdr_ptr;
744 Elf64_Nhdr *nhdr_ptr;
745
746 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
747 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
748 void *notes_section;
749 u64 offset, max_sz, sz, real_sz = 0;
750 if (phdr_ptr->p_type != PT_NOTE)
751 continue;
752 max_sz = phdr_ptr->p_memsz;
753 offset = phdr_ptr->p_offset;
754 notes_section = kmalloc(max_sz, GFP_KERNEL);
755 if (!notes_section)
756 return -ENOMEM;
757 rc = elfcorehdr_read_notes(buf: notes_section, count: max_sz, ppos: &offset);
758 if (rc < 0) {
759 kfree(objp: notes_section);
760 return rc;
761 }
762 nhdr_ptr = notes_section;
763 while (nhdr_ptr->n_namesz != 0) {
764 sz = sizeof(Elf64_Nhdr) +
765 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
766 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
767 if ((real_sz + sz) > max_sz) {
768 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
769 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
770 break;
771 }
772 real_sz += sz;
773 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
774 }
775 kfree(objp: notes_section);
776 phdr_ptr->p_memsz = real_sz;
777 if (real_sz == 0) {
778 pr_warn("Warning: Zero PT_NOTE entries found\n");
779 }
780 }
781
782 return 0;
783}
784
785/**
786 * get_note_number_and_size_elf64 - get the number of PT_NOTE program
787 * headers and sum of real size of their ELF note segment headers and
788 * data.
789 *
790 * @ehdr_ptr: ELF header
791 * @nr_ptnote: buffer for the number of PT_NOTE program headers
792 * @sz_ptnote: buffer for size of unique PT_NOTE program header
793 *
794 * This function is used to merge multiple PT_NOTE program headers
795 * into a unique single one. The resulting unique entry will have
796 * @sz_ptnote in its phdr->p_mem.
797 *
798 * It is assumed that program headers with PT_NOTE type pointed to by
799 * @ehdr_ptr has already been updated by update_note_header_size_elf64
800 * and each of PT_NOTE program headers has actual ELF note segment
801 * size in its p_memsz member.
802 */
803static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
804 int *nr_ptnote, u64 *sz_ptnote)
805{
806 int i;
807 Elf64_Phdr *phdr_ptr;
808
809 *nr_ptnote = *sz_ptnote = 0;
810
811 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
812 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
813 if (phdr_ptr->p_type != PT_NOTE)
814 continue;
815 *nr_ptnote += 1;
816 *sz_ptnote += phdr_ptr->p_memsz;
817 }
818
819 return 0;
820}
821
822/**
823 * copy_notes_elf64 - copy ELF note segments in a given buffer
824 *
825 * @ehdr_ptr: ELF header
826 * @notes_buf: buffer into which ELF note segments are copied
827 *
828 * This function is used to copy ELF note segment in the 1st kernel
829 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
830 * size of the buffer @notes_buf is equal to or larger than sum of the
831 * real ELF note segment headers and data.
832 *
833 * It is assumed that program headers with PT_NOTE type pointed to by
834 * @ehdr_ptr has already been updated by update_note_header_size_elf64
835 * and each of PT_NOTE program headers has actual ELF note segment
836 * size in its p_memsz member.
837 */
838static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
839{
840 int i, rc=0;
841 Elf64_Phdr *phdr_ptr;
842
843 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
844
845 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
846 u64 offset;
847 if (phdr_ptr->p_type != PT_NOTE)
848 continue;
849 offset = phdr_ptr->p_offset;
850 rc = elfcorehdr_read_notes(buf: notes_buf, count: phdr_ptr->p_memsz,
851 ppos: &offset);
852 if (rc < 0)
853 return rc;
854 notes_buf += phdr_ptr->p_memsz;
855 }
856
857 return 0;
858}
859
860/* Merges all the PT_NOTE headers into one. */
861static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
862 char **notes_buf, size_t *notes_sz)
863{
864 int i, nr_ptnote=0, rc=0;
865 char *tmp;
866 Elf64_Ehdr *ehdr_ptr;
867 Elf64_Phdr phdr;
868 u64 phdr_sz = 0, note_off;
869
870 ehdr_ptr = (Elf64_Ehdr *)elfptr;
871
872 rc = update_note_header_size_elf64(ehdr_ptr);
873 if (rc < 0)
874 return rc;
875
876 rc = get_note_number_and_size_elf64(ehdr_ptr, nr_ptnote: &nr_ptnote, sz_ptnote: &phdr_sz);
877 if (rc < 0)
878 return rc;
879
880 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
881 *notes_buf = vmcore_alloc_buf(size: *notes_sz);
882 if (!*notes_buf)
883 return -ENOMEM;
884
885 rc = copy_notes_elf64(ehdr_ptr, notes_buf: *notes_buf);
886 if (rc < 0)
887 return rc;
888
889 /* Prepare merged PT_NOTE program header. */
890 phdr.p_type = PT_NOTE;
891 phdr.p_flags = 0;
892 note_off = sizeof(Elf64_Ehdr) +
893 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
894 phdr.p_offset = roundup(note_off, PAGE_SIZE);
895 phdr.p_vaddr = phdr.p_paddr = 0;
896 phdr.p_filesz = phdr.p_memsz = phdr_sz;
897 phdr.p_align = 4;
898
899 /* Add merged PT_NOTE program header*/
900 tmp = elfptr + sizeof(Elf64_Ehdr);
901 memcpy(tmp, &phdr, sizeof(phdr));
902 tmp += sizeof(phdr);
903
904 /* Remove unwanted PT_NOTE program headers. */
905 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
906 *elfsz = *elfsz - i;
907 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
908 memset(elfptr + *elfsz, 0, i);
909 *elfsz = roundup(*elfsz, PAGE_SIZE);
910
911 /* Modify e_phnum to reflect merged headers. */
912 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
913
914 /* Store the size of all notes. We need this to update the note
915 * header when the device dumps will be added.
916 */
917 elfnotes_orig_sz = phdr.p_memsz;
918
919 return 0;
920}
921
922/**
923 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
924 *
925 * @ehdr_ptr: ELF header
926 *
927 * This function updates p_memsz member of each PT_NOTE entry in the
928 * program header table pointed to by @ehdr_ptr to real size of ELF
929 * note segment.
930 */
931static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
932{
933 int i, rc=0;
934 Elf32_Phdr *phdr_ptr;
935 Elf32_Nhdr *nhdr_ptr;
936
937 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
938 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
939 void *notes_section;
940 u64 offset, max_sz, sz, real_sz = 0;
941 if (phdr_ptr->p_type != PT_NOTE)
942 continue;
943 max_sz = phdr_ptr->p_memsz;
944 offset = phdr_ptr->p_offset;
945 notes_section = kmalloc(max_sz, GFP_KERNEL);
946 if (!notes_section)
947 return -ENOMEM;
948 rc = elfcorehdr_read_notes(buf: notes_section, count: max_sz, ppos: &offset);
949 if (rc < 0) {
950 kfree(objp: notes_section);
951 return rc;
952 }
953 nhdr_ptr = notes_section;
954 while (nhdr_ptr->n_namesz != 0) {
955 sz = sizeof(Elf32_Nhdr) +
956 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
957 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
958 if ((real_sz + sz) > max_sz) {
959 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
960 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
961 break;
962 }
963 real_sz += sz;
964 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
965 }
966 kfree(objp: notes_section);
967 phdr_ptr->p_memsz = real_sz;
968 if (real_sz == 0) {
969 pr_warn("Warning: Zero PT_NOTE entries found\n");
970 }
971 }
972
973 return 0;
974}
975
976/**
977 * get_note_number_and_size_elf32 - get the number of PT_NOTE program
978 * headers and sum of real size of their ELF note segment headers and
979 * data.
980 *
981 * @ehdr_ptr: ELF header
982 * @nr_ptnote: buffer for the number of PT_NOTE program headers
983 * @sz_ptnote: buffer for size of unique PT_NOTE program header
984 *
985 * This function is used to merge multiple PT_NOTE program headers
986 * into a unique single one. The resulting unique entry will have
987 * @sz_ptnote in its phdr->p_mem.
988 *
989 * It is assumed that program headers with PT_NOTE type pointed to by
990 * @ehdr_ptr has already been updated by update_note_header_size_elf32
991 * and each of PT_NOTE program headers has actual ELF note segment
992 * size in its p_memsz member.
993 */
994static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
995 int *nr_ptnote, u64 *sz_ptnote)
996{
997 int i;
998 Elf32_Phdr *phdr_ptr;
999
1000 *nr_ptnote = *sz_ptnote = 0;
1001
1002 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
1003 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1004 if (phdr_ptr->p_type != PT_NOTE)
1005 continue;
1006 *nr_ptnote += 1;
1007 *sz_ptnote += phdr_ptr->p_memsz;
1008 }
1009
1010 return 0;
1011}
1012
1013/**
1014 * copy_notes_elf32 - copy ELF note segments in a given buffer
1015 *
1016 * @ehdr_ptr: ELF header
1017 * @notes_buf: buffer into which ELF note segments are copied
1018 *
1019 * This function is used to copy ELF note segment in the 1st kernel
1020 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
1021 * size of the buffer @notes_buf is equal to or larger than sum of the
1022 * real ELF note segment headers and data.
1023 *
1024 * It is assumed that program headers with PT_NOTE type pointed to by
1025 * @ehdr_ptr has already been updated by update_note_header_size_elf32
1026 * and each of PT_NOTE program headers has actual ELF note segment
1027 * size in its p_memsz member.
1028 */
1029static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
1030{
1031 int i, rc=0;
1032 Elf32_Phdr *phdr_ptr;
1033
1034 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
1035
1036 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1037 u64 offset;
1038 if (phdr_ptr->p_type != PT_NOTE)
1039 continue;
1040 offset = phdr_ptr->p_offset;
1041 rc = elfcorehdr_read_notes(buf: notes_buf, count: phdr_ptr->p_memsz,
1042 ppos: &offset);
1043 if (rc < 0)
1044 return rc;
1045 notes_buf += phdr_ptr->p_memsz;
1046 }
1047
1048 return 0;
1049}
1050
1051/* Merges all the PT_NOTE headers into one. */
1052static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
1053 char **notes_buf, size_t *notes_sz)
1054{
1055 int i, nr_ptnote=0, rc=0;
1056 char *tmp;
1057 Elf32_Ehdr *ehdr_ptr;
1058 Elf32_Phdr phdr;
1059 u64 phdr_sz = 0, note_off;
1060
1061 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1062
1063 rc = update_note_header_size_elf32(ehdr_ptr);
1064 if (rc < 0)
1065 return rc;
1066
1067 rc = get_note_number_and_size_elf32(ehdr_ptr, nr_ptnote: &nr_ptnote, sz_ptnote: &phdr_sz);
1068 if (rc < 0)
1069 return rc;
1070
1071 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
1072 *notes_buf = vmcore_alloc_buf(size: *notes_sz);
1073 if (!*notes_buf)
1074 return -ENOMEM;
1075
1076 rc = copy_notes_elf32(ehdr_ptr, notes_buf: *notes_buf);
1077 if (rc < 0)
1078 return rc;
1079
1080 /* Prepare merged PT_NOTE program header. */
1081 phdr.p_type = PT_NOTE;
1082 phdr.p_flags = 0;
1083 note_off = sizeof(Elf32_Ehdr) +
1084 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
1085 phdr.p_offset = roundup(note_off, PAGE_SIZE);
1086 phdr.p_vaddr = phdr.p_paddr = 0;
1087 phdr.p_filesz = phdr.p_memsz = phdr_sz;
1088 phdr.p_align = 4;
1089
1090 /* Add merged PT_NOTE program header*/
1091 tmp = elfptr + sizeof(Elf32_Ehdr);
1092 memcpy(tmp, &phdr, sizeof(phdr));
1093 tmp += sizeof(phdr);
1094
1095 /* Remove unwanted PT_NOTE program headers. */
1096 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
1097 *elfsz = *elfsz - i;
1098 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
1099 memset(elfptr + *elfsz, 0, i);
1100 *elfsz = roundup(*elfsz, PAGE_SIZE);
1101
1102 /* Modify e_phnum to reflect merged headers. */
1103 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
1104
1105 /* Store the size of all notes. We need this to update the note
1106 * header when the device dumps will be added.
1107 */
1108 elfnotes_orig_sz = phdr.p_memsz;
1109
1110 return 0;
1111}
1112
1113/* Add memory chunks represented by program headers to vmcore list. Also update
1114 * the new offset fields of exported program headers. */
1115static int __init process_ptload_program_headers_elf64(char *elfptr,
1116 size_t elfsz,
1117 size_t elfnotes_sz,
1118 struct list_head *vc_list)
1119{
1120 int i;
1121 Elf64_Ehdr *ehdr_ptr;
1122 Elf64_Phdr *phdr_ptr;
1123 loff_t vmcore_off;
1124
1125 ehdr_ptr = (Elf64_Ehdr *)elfptr;
1126 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
1127
1128 /* Skip ELF header, program headers and ELF note segment. */
1129 vmcore_off = elfsz + elfnotes_sz;
1130
1131 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1132 u64 paddr, start, end, size;
1133
1134 if (phdr_ptr->p_type != PT_LOAD)
1135 continue;
1136
1137 paddr = phdr_ptr->p_offset;
1138 start = rounddown(paddr, PAGE_SIZE);
1139 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1140 size = end - start;
1141
1142 if (vmcore_alloc_add_range(list: vc_list, paddr: start, size))
1143 return -ENOMEM;
1144
1145 /* Update the program header offset. */
1146 phdr_ptr->p_offset = vmcore_off + (paddr - start);
1147 vmcore_off = vmcore_off + size;
1148 }
1149 return 0;
1150}
1151
1152static int __init process_ptload_program_headers_elf32(char *elfptr,
1153 size_t elfsz,
1154 size_t elfnotes_sz,
1155 struct list_head *vc_list)
1156{
1157 int i;
1158 Elf32_Ehdr *ehdr_ptr;
1159 Elf32_Phdr *phdr_ptr;
1160 loff_t vmcore_off;
1161
1162 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1163 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
1164
1165 /* Skip ELF header, program headers and ELF note segment. */
1166 vmcore_off = elfsz + elfnotes_sz;
1167
1168 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1169 u64 paddr, start, end, size;
1170
1171 if (phdr_ptr->p_type != PT_LOAD)
1172 continue;
1173
1174 paddr = phdr_ptr->p_offset;
1175 start = rounddown(paddr, PAGE_SIZE);
1176 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1177 size = end - start;
1178
1179 if (vmcore_alloc_add_range(list: vc_list, paddr: start, size))
1180 return -ENOMEM;
1181
1182 /* Update the program header offset */
1183 phdr_ptr->p_offset = vmcore_off + (paddr - start);
1184 vmcore_off = vmcore_off + size;
1185 }
1186 return 0;
1187}
1188
1189/* Sets offset fields of vmcore elements. */
1190static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
1191 struct list_head *vc_list)
1192{
1193 struct vmcore_range *m;
1194 loff_t vmcore_off;
1195
1196 /* Skip ELF header, program headers and ELF note segment. */
1197 vmcore_off = elfsz + elfnotes_sz;
1198
1199 list_for_each_entry(m, vc_list, list) {
1200 m->offset = vmcore_off;
1201 vmcore_off += m->size;
1202 }
1203}
1204
1205static void free_elfcorebuf(void)
1206{
1207 free_pages(addr: (unsigned long)elfcorebuf, order: get_order(size: elfcorebuf_sz_orig));
1208 elfcorebuf = NULL;
1209 vfree(addr: elfnotes_buf);
1210 elfnotes_buf = NULL;
1211}
1212
1213static int __init parse_crash_elf64_headers(void)
1214{
1215 int rc=0;
1216 Elf64_Ehdr ehdr;
1217 u64 addr;
1218
1219 addr = elfcorehdr_addr;
1220
1221 /* Read ELF header */
1222 rc = elfcorehdr_read(buf: (char *)&ehdr, count: sizeof(Elf64_Ehdr), ppos: &addr);
1223 if (rc < 0)
1224 return rc;
1225
1226 /* Do some basic Verification. */
1227 if (memcmp(p: ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
1228 (ehdr.e_type != ET_CORE) ||
1229 !vmcore_elf64_check_arch(&ehdr) ||
1230 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
1231 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
1232 ehdr.e_version != EV_CURRENT ||
1233 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
1234 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
1235 ehdr.e_phnum == 0) {
1236 pr_warn("Warning: Core image elf header is not sane\n");
1237 return -EINVAL;
1238 }
1239
1240 /* Read in all elf headers. */
1241 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
1242 ehdr.e_phnum * sizeof(Elf64_Phdr);
1243 elfcorebuf_sz = elfcorebuf_sz_orig;
1244 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1245 get_order(elfcorebuf_sz_orig));
1246 if (!elfcorebuf)
1247 return -ENOMEM;
1248 addr = elfcorehdr_addr;
1249 rc = elfcorehdr_read(buf: elfcorebuf, count: elfcorebuf_sz_orig, ppos: &addr);
1250 if (rc < 0)
1251 goto fail;
1252
1253 /* Merge all PT_NOTE headers into one. */
1254 rc = merge_note_headers_elf64(elfptr: elfcorebuf, elfsz: &elfcorebuf_sz,
1255 notes_buf: &elfnotes_buf, notes_sz: &elfnotes_sz);
1256 if (rc)
1257 goto fail;
1258 rc = process_ptload_program_headers_elf64(elfptr: elfcorebuf, elfsz: elfcorebuf_sz,
1259 elfnotes_sz, vc_list: &vmcore_list);
1260 if (rc)
1261 goto fail;
1262 set_vmcore_list_offsets(elfsz: elfcorebuf_sz, elfnotes_sz, vc_list: &vmcore_list);
1263 return 0;
1264fail:
1265 free_elfcorebuf();
1266 return rc;
1267}
1268
1269static int __init parse_crash_elf32_headers(void)
1270{
1271 int rc=0;
1272 Elf32_Ehdr ehdr;
1273 u64 addr;
1274
1275 addr = elfcorehdr_addr;
1276
1277 /* Read ELF header */
1278 rc = elfcorehdr_read(buf: (char *)&ehdr, count: sizeof(Elf32_Ehdr), ppos: &addr);
1279 if (rc < 0)
1280 return rc;
1281
1282 /* Do some basic Verification. */
1283 if (memcmp(p: ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
1284 (ehdr.e_type != ET_CORE) ||
1285 !vmcore_elf32_check_arch(&ehdr) ||
1286 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
1287 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
1288 ehdr.e_version != EV_CURRENT ||
1289 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
1290 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
1291 ehdr.e_phnum == 0) {
1292 pr_warn("Warning: Core image elf header is not sane\n");
1293 return -EINVAL;
1294 }
1295
1296 /* Read in all elf headers. */
1297 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
1298 elfcorebuf_sz = elfcorebuf_sz_orig;
1299 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1300 get_order(elfcorebuf_sz_orig));
1301 if (!elfcorebuf)
1302 return -ENOMEM;
1303 addr = elfcorehdr_addr;
1304 rc = elfcorehdr_read(buf: elfcorebuf, count: elfcorebuf_sz_orig, ppos: &addr);
1305 if (rc < 0)
1306 goto fail;
1307
1308 /* Merge all PT_NOTE headers into one. */
1309 rc = merge_note_headers_elf32(elfptr: elfcorebuf, elfsz: &elfcorebuf_sz,
1310 notes_buf: &elfnotes_buf, notes_sz: &elfnotes_sz);
1311 if (rc)
1312 goto fail;
1313 rc = process_ptload_program_headers_elf32(elfptr: elfcorebuf, elfsz: elfcorebuf_sz,
1314 elfnotes_sz, vc_list: &vmcore_list);
1315 if (rc)
1316 goto fail;
1317 set_vmcore_list_offsets(elfsz: elfcorebuf_sz, elfnotes_sz, vc_list: &vmcore_list);
1318 return 0;
1319fail:
1320 free_elfcorebuf();
1321 return rc;
1322}
1323
1324static int __init parse_crash_elf_headers(void)
1325{
1326 unsigned char e_ident[EI_NIDENT];
1327 u64 addr;
1328 int rc=0;
1329
1330 addr = elfcorehdr_addr;
1331 rc = elfcorehdr_read(buf: e_ident, EI_NIDENT, ppos: &addr);
1332 if (rc < 0)
1333 return rc;
1334 if (memcmp(p: e_ident, ELFMAG, SELFMAG) != 0) {
1335 pr_warn("Warning: Core image elf header not found\n");
1336 return -EINVAL;
1337 }
1338
1339 if (e_ident[EI_CLASS] == ELFCLASS64) {
1340 rc = parse_crash_elf64_headers();
1341 if (rc)
1342 return rc;
1343 } else if (e_ident[EI_CLASS] == ELFCLASS32) {
1344 rc = parse_crash_elf32_headers();
1345 if (rc)
1346 return rc;
1347 } else {
1348 pr_warn("Warning: Core image elf header is not sane\n");
1349 return -EINVAL;
1350 }
1351
1352 /* Determine vmcore size. */
1353 vmcore_size = get_vmcore_size(elfsz: elfcorebuf_sz, elfnotesegsz: elfnotes_sz,
1354 vc_list: &vmcore_list);
1355
1356 return 0;
1357}
1358
1359#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
1360/**
1361 * vmcoredd_write_header - Write vmcore device dump header at the
1362 * beginning of the dump's buffer.
1363 * @buf: Output buffer where the note is written
1364 * @data: Dump info
1365 * @size: Size of the dump
1366 *
1367 * Fills beginning of the dump's buffer with vmcore device dump header.
1368 */
1369static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data,
1370 u32 size)
1371{
1372 struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf;
1373
1374 vdd_hdr->n_namesz = sizeof(vdd_hdr->name);
1375 vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name);
1376 vdd_hdr->n_type = NT_VMCOREDD;
1377
1378 strscpy_pad(vdd_hdr->name, VMCOREDD_NOTE_NAME);
1379 strscpy_pad(vdd_hdr->dump_name, data->dump_name);
1380}
1381
1382/**
1383 * vmcoredd_update_program_headers - Update all ELF program headers
1384 * @elfptr: Pointer to elf header
1385 * @elfnotesz: Size of elf notes aligned to page size
1386 * @vmcoreddsz: Size of device dumps to be added to elf note header
1387 *
1388 * Determine type of ELF header (Elf64 or Elf32) and update the elf note size.
1389 * Also update the offsets of all the program headers after the elf note header.
1390 */
1391static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz,
1392 size_t vmcoreddsz)
1393{
1394 unsigned char *e_ident = (unsigned char *)elfptr;
1395 u64 start, end, size;
1396 loff_t vmcore_off;
1397 u32 i;
1398
1399 vmcore_off = elfcorebuf_sz + elfnotesz;
1400
1401 if (e_ident[EI_CLASS] == ELFCLASS64) {
1402 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr;
1403 Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr));
1404
1405 /* Update all program headers */
1406 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
1407 if (phdr->p_type == PT_NOTE) {
1408 /* Update note size */
1409 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
1410 phdr->p_filesz = phdr->p_memsz;
1411 continue;
1412 }
1413
1414 start = rounddown(phdr->p_offset, PAGE_SIZE);
1415 end = roundup(phdr->p_offset + phdr->p_memsz,
1416 PAGE_SIZE);
1417 size = end - start;
1418 phdr->p_offset = vmcore_off + (phdr->p_offset - start);
1419 vmcore_off += size;
1420 }
1421 } else {
1422 Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr;
1423 Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr));
1424
1425 /* Update all program headers */
1426 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
1427 if (phdr->p_type == PT_NOTE) {
1428 /* Update note size */
1429 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
1430 phdr->p_filesz = phdr->p_memsz;
1431 continue;
1432 }
1433
1434 start = rounddown(phdr->p_offset, PAGE_SIZE);
1435 end = roundup(phdr->p_offset + phdr->p_memsz,
1436 PAGE_SIZE);
1437 size = end - start;
1438 phdr->p_offset = vmcore_off + (phdr->p_offset - start);
1439 vmcore_off += size;
1440 }
1441 }
1442}
1443
1444/**
1445 * vmcoredd_update_size - Update the total size of the device dumps and update
1446 * ELF header
1447 * @dump_size: Size of the current device dump to be added to total size
1448 *
1449 * Update the total size of all the device dumps and update the ELF program
1450 * headers. Calculate the new offsets for the vmcore list and update the
1451 * total vmcore size.
1452 */
1453static void vmcoredd_update_size(size_t dump_size)
1454{
1455 vmcoredd_orig_sz += dump_size;
1456 elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz;
1457 vmcoredd_update_program_headers(elfptr: elfcorebuf, elfnotesz: elfnotes_sz,
1458 vmcoreddsz: vmcoredd_orig_sz);
1459
1460 /* Update vmcore list offsets */
1461 set_vmcore_list_offsets(elfsz: elfcorebuf_sz, elfnotes_sz, vc_list: &vmcore_list);
1462
1463 vmcore_size = get_vmcore_size(elfsz: elfcorebuf_sz, elfnotesegsz: elfnotes_sz,
1464 vc_list: &vmcore_list);
1465 proc_vmcore->size = vmcore_size;
1466}
1467
1468/**
1469 * vmcore_add_device_dump - Add a buffer containing device dump to vmcore
1470 * @data: dump info.
1471 *
1472 * Allocate a buffer and invoke the calling driver's dump collect routine.
1473 * Write ELF note at the beginning of the buffer to indicate vmcore device
1474 * dump and add the dump to global list.
1475 */
1476int vmcore_add_device_dump(struct vmcoredd_data *data)
1477{
1478 struct vmcoredd_node *dump;
1479 void *buf = NULL;
1480 size_t data_size;
1481 int ret;
1482
1483 if (vmcoredd_disabled) {
1484 pr_err_once("Device dump is disabled\n");
1485 return -EINVAL;
1486 }
1487
1488 if (!data || !strlen(data->dump_name) ||
1489 !data->vmcoredd_callback || !data->size)
1490 return -EINVAL;
1491
1492 dump = vzalloc(sizeof(*dump));
1493 if (!dump)
1494 return -ENOMEM;
1495
1496 /* Keep size of the buffer page aligned so that it can be mmaped */
1497 data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
1498 PAGE_SIZE);
1499
1500 /* Allocate buffer for driver's to write their dumps */
1501 buf = vmcore_alloc_buf(size: data_size);
1502 if (!buf) {
1503 ret = -ENOMEM;
1504 goto out_err;
1505 }
1506
1507 vmcoredd_write_header(buf, data, size: data_size -
1508 sizeof(struct vmcoredd_header));
1509
1510 /* Invoke the driver's dump collection routing */
1511 ret = data->vmcoredd_callback(data, buf +
1512 sizeof(struct vmcoredd_header));
1513 if (ret)
1514 goto out_err;
1515
1516 dump->buf = buf;
1517 dump->size = data_size;
1518
1519 /* Add the dump to driver sysfs list and update the elfcore hdr */
1520 scoped_guard(mutex, &vmcore_mutex) {
1521 if (vmcore_opened)
1522 pr_warn_once("Unexpected adding of device dump\n");
1523 if (vmcore_open) {
1524 ret = -EBUSY;
1525 goto out_err;
1526 }
1527
1528 list_add_tail(new: &dump->list, head: &vmcoredd_list);
1529 vmcoredd_update_size(dump_size: data_size);
1530 }
1531 return 0;
1532
1533out_err:
1534 vfree(addr: buf);
1535 vfree(addr: dump);
1536
1537 return ret;
1538}
1539EXPORT_SYMBOL(vmcore_add_device_dump);
1540#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1541
1542#ifdef CONFIG_PROC_VMCORE_DEVICE_RAM
1543static int vmcore_realloc_elfcore_buffer_elf64(size_t new_size)
1544{
1545 char *elfcorebuf_new;
1546
1547 if (WARN_ON_ONCE(new_size < elfcorebuf_sz))
1548 return -EINVAL;
1549 if (get_order(elfcorebuf_sz_orig) == get_order(new_size)) {
1550 elfcorebuf_sz_orig = new_size;
1551 return 0;
1552 }
1553
1554 elfcorebuf_new = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1555 get_order(new_size));
1556 if (!elfcorebuf_new)
1557 return -ENOMEM;
1558 memcpy(elfcorebuf_new, elfcorebuf, elfcorebuf_sz);
1559 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
1560 elfcorebuf = elfcorebuf_new;
1561 elfcorebuf_sz_orig = new_size;
1562 return 0;
1563}
1564
1565static void vmcore_reset_offsets_elf64(void)
1566{
1567 Elf64_Phdr *phdr_start = (Elf64_Phdr *)(elfcorebuf + sizeof(Elf64_Ehdr));
1568 loff_t vmcore_off = elfcorebuf_sz + elfnotes_sz;
1569 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfcorebuf;
1570 Elf64_Phdr *phdr;
1571 int i;
1572
1573 for (i = 0, phdr = phdr_start; i < ehdr->e_phnum; i++, phdr++) {
1574 u64 start, end;
1575
1576 /*
1577 * After merge_note_headers_elf64() we should only have a single
1578 * PT_NOTE entry that starts immediately after elfcorebuf_sz.
1579 */
1580 if (phdr->p_type == PT_NOTE) {
1581 phdr->p_offset = elfcorebuf_sz;
1582 continue;
1583 }
1584
1585 start = rounddown(phdr->p_offset, PAGE_SIZE);
1586 end = roundup(phdr->p_offset + phdr->p_memsz, PAGE_SIZE);
1587 phdr->p_offset = vmcore_off + (phdr->p_offset - start);
1588 vmcore_off = vmcore_off + end - start;
1589 }
1590 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1591}
1592
1593static int vmcore_add_device_ram_elf64(struct list_head *list, size_t count)
1594{
1595 Elf64_Phdr *phdr_start = (Elf64_Phdr *)(elfcorebuf + sizeof(Elf64_Ehdr));
1596 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfcorebuf;
1597 struct vmcore_range *cur;
1598 Elf64_Phdr *phdr;
1599 size_t new_size;
1600 int rc;
1601
1602 if ((Elf32_Half)(ehdr->e_phnum + count) != ehdr->e_phnum + count) {
1603 pr_err("too many device ram ranges\n");
1604 return -ENOSPC;
1605 }
1606
1607 /* elfcorebuf_sz must always cover full pages. */
1608 new_size = sizeof(Elf64_Ehdr) +
1609 (ehdr->e_phnum + count) * sizeof(Elf64_Phdr);
1610 new_size = roundup(new_size, PAGE_SIZE);
1611
1612 /*
1613 * Make sure we have sufficient space to include the new PT_LOAD
1614 * entries.
1615 */
1616 rc = vmcore_realloc_elfcore_buffer_elf64(new_size);
1617 if (rc) {
1618 pr_err("resizing elfcore failed\n");
1619 return rc;
1620 }
1621
1622 /* Modify our used elfcore buffer size to cover the new entries. */
1623 elfcorebuf_sz = new_size;
1624
1625 /* Fill the added PT_LOAD entries. */
1626 phdr = phdr_start + ehdr->e_phnum;
1627 list_for_each_entry(cur, list, list) {
1628 WARN_ON_ONCE(!IS_ALIGNED(cur->paddr | cur->size, PAGE_SIZE));
1629 elfcorehdr_fill_device_ram_ptload_elf64(phdr, cur->paddr, cur->size);
1630
1631 /* p_offset will be adjusted later. */
1632 phdr++;
1633 ehdr->e_phnum++;
1634 }
1635 list_splice_tail(list, &vmcore_list);
1636
1637 /* We changed elfcorebuf_sz and added new entries; reset all offsets. */
1638 vmcore_reset_offsets_elf64();
1639
1640 /* Finally, recalculate the total vmcore size. */
1641 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
1642 &vmcore_list);
1643 proc_vmcore->size = vmcore_size;
1644 return 0;
1645}
1646
1647static void vmcore_process_device_ram(struct vmcore_cb *cb)
1648{
1649 unsigned char *e_ident = (unsigned char *)elfcorebuf;
1650 struct vmcore_range *first, *m;
1651 LIST_HEAD(list);
1652 int count;
1653
1654 /* We only support Elf64 dumps for now. */
1655 if (WARN_ON_ONCE(e_ident[EI_CLASS] != ELFCLASS64)) {
1656 pr_err("device ram ranges only support Elf64\n");
1657 return;
1658 }
1659
1660 if (cb->get_device_ram(cb, &list)) {
1661 pr_err("obtaining device ram ranges failed\n");
1662 return;
1663 }
1664 count = list_count_nodes(&list);
1665 if (!count)
1666 return;
1667
1668 /*
1669 * For some reason these ranges are already know? Might happen
1670 * with unusual register->unregister->register sequences; we'll simply
1671 * sanity check using the first range.
1672 */
1673 first = list_first_entry(&list, struct vmcore_range, list);
1674 list_for_each_entry(m, &vmcore_list, list) {
1675 unsigned long long m_end = m->paddr + m->size;
1676 unsigned long long first_end = first->paddr + first->size;
1677
1678 if (first->paddr < m_end && m->paddr < first_end)
1679 goto out_free;
1680 }
1681
1682 /* If adding the mem nodes succeeds, they must not be freed. */
1683 if (!vmcore_add_device_ram_elf64(&list, count))
1684 return;
1685out_free:
1686 vmcore_free_ranges(&list);
1687}
1688#else /* !CONFIG_PROC_VMCORE_DEVICE_RAM */
1689static void vmcore_process_device_ram(struct vmcore_cb *cb)
1690{
1691}
1692#endif /* CONFIG_PROC_VMCORE_DEVICE_RAM */
1693
1694/* Free all dumps in vmcore device dump list */
1695static void vmcore_free_device_dumps(void)
1696{
1697#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
1698 mutex_lock(&vmcore_mutex);
1699 while (!list_empty(head: &vmcoredd_list)) {
1700 struct vmcoredd_node *dump;
1701
1702 dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node,
1703 list);
1704 list_del(entry: &dump->list);
1705 vfree(addr: dump->buf);
1706 vfree(addr: dump);
1707 }
1708 mutex_unlock(lock: &vmcore_mutex);
1709#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1710}
1711
1712/* Init function for vmcore module. */
1713static int __init vmcore_init(void)
1714{
1715 int rc = 0;
1716
1717 /* Allow architectures to allocate ELF header in 2nd kernel */
1718 rc = elfcorehdr_alloc(addr: &elfcorehdr_addr, size: &elfcorehdr_size);
1719 if (rc)
1720 return rc;
1721 /*
1722 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
1723 * then capture the dump.
1724 */
1725 if (!(is_vmcore_usable()))
1726 return rc;
1727 rc = parse_crash_elf_headers();
1728 if (rc) {
1729 elfcorehdr_free(addr: elfcorehdr_addr);
1730 pr_warn("not initialized\n");
1731 return rc;
1732 }
1733 elfcorehdr_free(addr: elfcorehdr_addr);
1734 elfcorehdr_addr = ELFCORE_ADDR_ERR;
1735
1736 proc_vmcore = proc_create(name: "vmcore", S_IRUSR, NULL, proc_ops: &vmcore_proc_ops);
1737 if (proc_vmcore)
1738 proc_vmcore->size = vmcore_size;
1739 return 0;
1740}
1741fs_initcall(vmcore_init);
1742
1743/* Cleanup function for vmcore module. */
1744void vmcore_cleanup(void)
1745{
1746 if (proc_vmcore) {
1747 proc_remove(proc_vmcore);
1748 proc_vmcore = NULL;
1749 }
1750
1751 vmcore_free_ranges(list: &vmcore_list);
1752 free_elfcorebuf();
1753
1754 /* clear vmcore device dump list */
1755 vmcore_free_device_dumps();
1756}
1757

source code of linux/fs/proc/vmcore.c