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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 */
36static LIST_HEAD(vmcore_list);
37
38/* Stores the pointer to the buffer containing kernel elf core headers. */
39static char *elfcorebuf;
40static size_t elfcorebuf_sz;
41static size_t elfcorebuf_sz_orig;
42
43static char *elfnotes_buf;
44static size_t elfnotes_sz;
45/* Size of all notes minus the device dump notes */
46static size_t elfnotes_orig_sz;
47
48/* Total size of vmcore file. */
49static u64 vmcore_size;
50
51static 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 */
55static LIST_HEAD(vmcoredd_list);
56static DEFINE_MUTEX(vmcoredd_mutex);
57
58static bool vmcoredd_disabled;
59core_param(novmcoredd, vmcoredd_disabled, bool, 0);
60#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
61
62/* Device Dump Size */
63static size_t vmcoredd_orig_sz;
64
65static DEFINE_SPINLOCK(vmcore_cb_lock);
66DEFINE_STATIC_SRCU(vmcore_cb_srcu);
67/* List of registered vmcore callbacks. */
68static LIST_HEAD(vmcore_cb_list);
69/* Whether the vmcore has been opened once. */
70static bool vmcore_opened;
71
72void register_vmcore_cb(struct vmcore_cb *cb)
73{
74 INIT_LIST_HEAD(&cb->next);
75 spin_lock(&vmcore_cb_lock);
76 list_add_tail(&cb->next, &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(&vmcore_cb_lock);
84}
85EXPORT_SYMBOL_GPL(register_vmcore_cb);
86
87void unregister_vmcore_cb(struct vmcore_cb *cb)
88{
89 spin_lock(&vmcore_cb_lock);
90 list_del_rcu(&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(&vmcore_cb_lock);
99
100 synchronize_srcu(&vmcore_cb_srcu);
101}
102EXPORT_SYMBOL_GPL(unregister_vmcore_cb);
103
104static 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
121static int open_vmcore(struct inode *inode, struct file *file)
122{
123 spin_lock(&vmcore_cb_lock);
124 vmcore_opened = true;
125 spin_unlock(&vmcore_cb_lock);
126
127 return 0;
128}
129
130/* Reads a page from the oldmem device from given offset. */
131ssize_t read_from_oldmem(struct iov_iter *iter, size_t count,
132 u64 *ppos, bool encrypted)
133{
134 unsigned long pfn, offset;
135 size_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(&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(nr_bytes, iter);
155 } else {
156 if (encrypted)
157 tmp = copy_oldmem_page_encrypted(iter, pfn,
158 nr_bytes,
159 offset);
160 else
161 tmp = copy_oldmem_page(iter, pfn, nr_bytes,
162 offset);
163 }
164 if (tmp < nr_bytes) {
165 srcu_read_unlock(&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(&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 */
183int __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 */
191void __weak elfcorehdr_free(unsigned long long addr)
192{}
193
194/*
195 * Architectures may override this function to read from ELF header
196 */
197ssize_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(&iter, ITER_DEST, &kvec, 1, count);
203
204 return read_from_oldmem(&iter, count, ppos, false);
205}
206
207/*
208 * Architectures may override this function to read from notes sections
209 */
210ssize_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(&iter, ITER_DEST, &kvec, 1, count);
216
217 return read_from_oldmem(&iter, count, ppos,
218 cc_platform_has(CC_ATTR_MEM_ENCRYPT));
219}
220
221/*
222 * Architectures may override this function to map oldmem
223 */
224int __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, from, pfn, size, prot);
230}
231
232/*
233 * Architectures which support memory encryption override this.
234 */
235ssize_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(iter, pfn, csize, offset);
239}
240
241#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
242static 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(buf, tsz, 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
270out_unlock:
271 mutex_unlock(&vmcoredd_mutex);
272 return ret;
273}
274
275#ifdef CONFIG_MMU
276static 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, dst, buf, 0,
291 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
307out_unlock:
308 mutex_unlock(&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 */
317static 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(iter) || *fpos >= vmcore_size)
325 return 0;
326
327 iov_iter_truncate(iter, 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(elfcorebuf + *fpos, tsz, iter) < tsz)
333 return -EFAULT;
334 *fpos += tsz;
335 acc += tsz;
336
337 /* leave now if filled buffer already */
338 if (!iov_iter_count(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, tsz))
362 return -EFAULT;
363
364 *fpos += tsz;
365 acc += tsz;
366
367 /* leave now if filled buffer already */
368 if (!iov_iter_count(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(kaddr, tsz, 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(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, tsz, &start,
395 cc_platform_has(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(iter))
403 return acc;
404 }
405 }
406
407 return acc;
408}
409
410static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter)
411{
412 return __read_vmcore(iter, &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 */
422static 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
458static 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 */
472static 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 */
501static 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(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(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 + len,
524 pos_start, 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 + len,
531 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 + len, pos_start,
542 map_size, prot))
543 goto fail;
544 }
545 return 0;
546fail:
547 do_munmap(vma->vm_mm, from, len, NULL);
548 return -EAGAIN;
549}
550
551static 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(&vmcore_cb_srcu);
562 if (!list_empty(&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(&vmcore_cb_srcu, idx);
567 return ret;
568}
569
570static 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 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
586 vma->vm_flags |= VM_MIXEDMAP;
587 vma->vm_ops = &vmcore_mmap_ops;
588
589 len = 0;
590
591 if (start < elfcorebuf_sz) {
592 u64 pfn;
593
594 tsz = min(elfcorebuf_sz - (size_t)start, size);
595 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
596 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
597 vma->vm_page_prot))
598 return -EAGAIN;
599 size -= tsz;
600 start += tsz;
601 len += tsz;
602
603 if (size == 0)
604 return 0;
605 }
606
607 if (start < elfcorebuf_sz + elfnotes_sz) {
608 void *kaddr;
609
610 /* We add device dumps before other elf notes because the
611 * other elf notes may not fill the elf notes buffer
612 * completely and we will end up with zero-filled data
613 * between the elf notes and the device dumps. Tools will
614 * then try to decode this zero-filled data as valid notes
615 * and we don't want that. Hence, adding device dumps before
616 * the other elf notes ensure that zero-filled data can be
617 * avoided. This also ensures that the device dumps and
618 * other elf notes can be properly mmaped at page aligned
619 * address.
620 */
621#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
622 /* Read device dumps */
623 if (start < elfcorebuf_sz + vmcoredd_orig_sz) {
624 u64 start_off;
625
626 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
627 (size_t)start, size);
628 start_off = start - elfcorebuf_sz;
629 if (vmcoredd_mmap_dumps(vma, vma->vm_start + len,
630 start_off, tsz))
631 goto fail;
632
633 size -= tsz;
634 start += tsz;
635 len += tsz;
636
637 /* leave now if filled buffer already */
638 if (!size)
639 return 0;
640 }
641#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
642
643 /* Read remaining elf notes */
644 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
645 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz;
646 if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
647 kaddr, 0, tsz))
648 goto fail;
649
650 size -= tsz;
651 start += tsz;
652 len += tsz;
653
654 if (size == 0)
655 return 0;
656 }
657
658 list_for_each_entry(m, &vmcore_list, list) {
659 if (start < m->offset + m->size) {
660 u64 paddr = 0;
661
662 tsz = (size_t)min_t(unsigned long long,
663 m->offset + m->size - start, size);
664 paddr = m->paddr + start - m->offset;
665 if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len,
666 paddr >> PAGE_SHIFT, tsz,
667 vma->vm_page_prot))
668 goto fail;
669 size -= tsz;
670 start += tsz;
671 len += tsz;
672
673 if (size == 0)
674 return 0;
675 }
676 }
677
678 return 0;
679fail:
680 do_munmap(vma->vm_mm, vma->vm_start, len, NULL);
681 return -EAGAIN;
682}
683#else
684static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
685{
686 return -ENOSYS;
687}
688#endif
689
690static const struct proc_ops vmcore_proc_ops = {
691 .proc_open = open_vmcore,
692 .proc_read_iter = read_vmcore,
693 .proc_lseek = default_llseek,
694 .proc_mmap = mmap_vmcore,
695};
696
697static struct vmcore* __init get_new_element(void)
698{
699 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
700}
701
702static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
703 struct list_head *vc_list)
704{
705 u64 size;
706 struct vmcore *m;
707
708 size = elfsz + elfnotesegsz;
709 list_for_each_entry(m, vc_list, list) {
710 size += m->size;
711 }
712 return size;
713}
714
715/**
716 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
717 *
718 * @ehdr_ptr: ELF header
719 *
720 * This function updates p_memsz member of each PT_NOTE entry in the
721 * program header table pointed to by @ehdr_ptr to real size of ELF
722 * note segment.
723 */
724static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
725{
726 int i, rc=0;
727 Elf64_Phdr *phdr_ptr;
728 Elf64_Nhdr *nhdr_ptr;
729
730 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
731 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
732 void *notes_section;
733 u64 offset, max_sz, sz, real_sz = 0;
734 if (phdr_ptr->p_type != PT_NOTE)
735 continue;
736 max_sz = phdr_ptr->p_memsz;
737 offset = phdr_ptr->p_offset;
738 notes_section = kmalloc(max_sz, GFP_KERNEL);
739 if (!notes_section)
740 return -ENOMEM;
741 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
742 if (rc < 0) {
743 kfree(notes_section);
744 return rc;
745 }
746 nhdr_ptr = notes_section;
747 while (nhdr_ptr->n_namesz != 0) {
748 sz = sizeof(Elf64_Nhdr) +
749 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
750 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
751 if ((real_sz + sz) > max_sz) {
752 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
753 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
754 break;
755 }
756 real_sz += sz;
757 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
758 }
759 kfree(notes_section);
760 phdr_ptr->p_memsz = real_sz;
761 if (real_sz == 0) {
762 pr_warn("Warning: Zero PT_NOTE entries found\n");
763 }
764 }
765
766 return 0;
767}
768
769/**
770 * get_note_number_and_size_elf64 - get the number of PT_NOTE program
771 * headers and sum of real size of their ELF note segment headers and
772 * data.
773 *
774 * @ehdr_ptr: ELF header
775 * @nr_ptnote: buffer for the number of PT_NOTE program headers
776 * @sz_ptnote: buffer for size of unique PT_NOTE program header
777 *
778 * This function is used to merge multiple PT_NOTE program headers
779 * into a unique single one. The resulting unique entry will have
780 * @sz_ptnote in its phdr->p_mem.
781 *
782 * It is assumed that program headers with PT_NOTE type pointed to by
783 * @ehdr_ptr has already been updated by update_note_header_size_elf64
784 * and each of PT_NOTE program headers has actual ELF note segment
785 * size in its p_memsz member.
786 */
787static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
788 int *nr_ptnote, u64 *sz_ptnote)
789{
790 int i;
791 Elf64_Phdr *phdr_ptr;
792
793 *nr_ptnote = *sz_ptnote = 0;
794
795 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
796 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
797 if (phdr_ptr->p_type != PT_NOTE)
798 continue;
799 *nr_ptnote += 1;
800 *sz_ptnote += phdr_ptr->p_memsz;
801 }
802
803 return 0;
804}
805
806/**
807 * copy_notes_elf64 - copy ELF note segments in a given buffer
808 *
809 * @ehdr_ptr: ELF header
810 * @notes_buf: buffer into which ELF note segments are copied
811 *
812 * This function is used to copy ELF note segment in the 1st kernel
813 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
814 * size of the buffer @notes_buf is equal to or larger than sum of the
815 * real ELF note segment headers and data.
816 *
817 * It is assumed that program headers with PT_NOTE type pointed to by
818 * @ehdr_ptr has already been updated by update_note_header_size_elf64
819 * and each of PT_NOTE program headers has actual ELF note segment
820 * size in its p_memsz member.
821 */
822static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
823{
824 int i, rc=0;
825 Elf64_Phdr *phdr_ptr;
826
827 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
828
829 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
830 u64 offset;
831 if (phdr_ptr->p_type != PT_NOTE)
832 continue;
833 offset = phdr_ptr->p_offset;
834 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
835 &offset);
836 if (rc < 0)
837 return rc;
838 notes_buf += phdr_ptr->p_memsz;
839 }
840
841 return 0;
842}
843
844/* Merges all the PT_NOTE headers into one. */
845static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
846 char **notes_buf, size_t *notes_sz)
847{
848 int i, nr_ptnote=0, rc=0;
849 char *tmp;
850 Elf64_Ehdr *ehdr_ptr;
851 Elf64_Phdr phdr;
852 u64 phdr_sz = 0, note_off;
853
854 ehdr_ptr = (Elf64_Ehdr *)elfptr;
855
856 rc = update_note_header_size_elf64(ehdr_ptr);
857 if (rc < 0)
858 return rc;
859
860 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
861 if (rc < 0)
862 return rc;
863
864 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
865 *notes_buf = vmcore_alloc_buf(*notes_sz);
866 if (!*notes_buf)
867 return -ENOMEM;
868
869 rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
870 if (rc < 0)
871 return rc;
872
873 /* Prepare merged PT_NOTE program header. */
874 phdr.p_type = PT_NOTE;
875 phdr.p_flags = 0;
876 note_off = sizeof(Elf64_Ehdr) +
877 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
878 phdr.p_offset = roundup(note_off, PAGE_SIZE);
879 phdr.p_vaddr = phdr.p_paddr = 0;
880 phdr.p_filesz = phdr.p_memsz = phdr_sz;
881 phdr.p_align = 0;
882
883 /* Add merged PT_NOTE program header*/
884 tmp = elfptr + sizeof(Elf64_Ehdr);
885 memcpy(tmp, &phdr, sizeof(phdr));
886 tmp += sizeof(phdr);
887
888 /* Remove unwanted PT_NOTE program headers. */
889 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
890 *elfsz = *elfsz - i;
891 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
892 memset(elfptr + *elfsz, 0, i);
893 *elfsz = roundup(*elfsz, PAGE_SIZE);
894
895 /* Modify e_phnum to reflect merged headers. */
896 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
897
898 /* Store the size of all notes. We need this to update the note
899 * header when the device dumps will be added.
900 */
901 elfnotes_orig_sz = phdr.p_memsz;
902
903 return 0;
904}
905
906/**
907 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
908 *
909 * @ehdr_ptr: ELF header
910 *
911 * This function updates p_memsz member of each PT_NOTE entry in the
912 * program header table pointed to by @ehdr_ptr to real size of ELF
913 * note segment.
914 */
915static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
916{
917 int i, rc=0;
918 Elf32_Phdr *phdr_ptr;
919 Elf32_Nhdr *nhdr_ptr;
920
921 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
922 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
923 void *notes_section;
924 u64 offset, max_sz, sz, real_sz = 0;
925 if (phdr_ptr->p_type != PT_NOTE)
926 continue;
927 max_sz = phdr_ptr->p_memsz;
928 offset = phdr_ptr->p_offset;
929 notes_section = kmalloc(max_sz, GFP_KERNEL);
930 if (!notes_section)
931 return -ENOMEM;
932 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
933 if (rc < 0) {
934 kfree(notes_section);
935 return rc;
936 }
937 nhdr_ptr = notes_section;
938 while (nhdr_ptr->n_namesz != 0) {
939 sz = sizeof(Elf32_Nhdr) +
940 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
941 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
942 if ((real_sz + sz) > max_sz) {
943 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
944 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
945 break;
946 }
947 real_sz += sz;
948 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
949 }
950 kfree(notes_section);
951 phdr_ptr->p_memsz = real_sz;
952 if (real_sz == 0) {
953 pr_warn("Warning: Zero PT_NOTE entries found\n");
954 }
955 }
956
957 return 0;
958}
959
960/**
961 * get_note_number_and_size_elf32 - get the number of PT_NOTE program
962 * headers and sum of real size of their ELF note segment headers and
963 * data.
964 *
965 * @ehdr_ptr: ELF header
966 * @nr_ptnote: buffer for the number of PT_NOTE program headers
967 * @sz_ptnote: buffer for size of unique PT_NOTE program header
968 *
969 * This function is used to merge multiple PT_NOTE program headers
970 * into a unique single one. The resulting unique entry will have
971 * @sz_ptnote in its phdr->p_mem.
972 *
973 * It is assumed that program headers with PT_NOTE type pointed to by
974 * @ehdr_ptr has already been updated by update_note_header_size_elf32
975 * and each of PT_NOTE program headers has actual ELF note segment
976 * size in its p_memsz member.
977 */
978static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
979 int *nr_ptnote, u64 *sz_ptnote)
980{
981 int i;
982 Elf32_Phdr *phdr_ptr;
983
984 *nr_ptnote = *sz_ptnote = 0;
985
986 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
987 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
988 if (phdr_ptr->p_type != PT_NOTE)
989 continue;
990 *nr_ptnote += 1;
991 *sz_ptnote += phdr_ptr->p_memsz;
992 }
993
994 return 0;
995}
996
997/**
998 * copy_notes_elf32 - copy ELF note segments in a given buffer
999 *
1000 * @ehdr_ptr: ELF header
1001 * @notes_buf: buffer into which ELF note segments are copied
1002 *
1003 * This function is used to copy ELF note segment in the 1st kernel
1004 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
1005 * size of the buffer @notes_buf is equal to or larger than sum of the
1006 * real ELF note segment headers and data.
1007 *
1008 * It is assumed that program headers with PT_NOTE type pointed to by
1009 * @ehdr_ptr has already been updated by update_note_header_size_elf32
1010 * and each of PT_NOTE program headers has actual ELF note segment
1011 * size in its p_memsz member.
1012 */
1013static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
1014{
1015 int i, rc=0;
1016 Elf32_Phdr *phdr_ptr;
1017
1018 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
1019
1020 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1021 u64 offset;
1022 if (phdr_ptr->p_type != PT_NOTE)
1023 continue;
1024 offset = phdr_ptr->p_offset;
1025 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
1026 &offset);
1027 if (rc < 0)
1028 return rc;
1029 notes_buf += phdr_ptr->p_memsz;
1030 }
1031
1032 return 0;
1033}
1034
1035/* Merges all the PT_NOTE headers into one. */
1036static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
1037 char **notes_buf, size_t *notes_sz)
1038{
1039 int i, nr_ptnote=0, rc=0;
1040 char *tmp;
1041 Elf32_Ehdr *ehdr_ptr;
1042 Elf32_Phdr phdr;
1043 u64 phdr_sz = 0, note_off;
1044
1045 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1046
1047 rc = update_note_header_size_elf32(ehdr_ptr);
1048 if (rc < 0)
1049 return rc;
1050
1051 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
1052 if (rc < 0)
1053 return rc;
1054
1055 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
1056 *notes_buf = vmcore_alloc_buf(*notes_sz);
1057 if (!*notes_buf)
1058 return -ENOMEM;
1059
1060 rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
1061 if (rc < 0)
1062 return rc;
1063
1064 /* Prepare merged PT_NOTE program header. */
1065 phdr.p_type = PT_NOTE;
1066 phdr.p_flags = 0;
1067 note_off = sizeof(Elf32_Ehdr) +
1068 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
1069 phdr.p_offset = roundup(note_off, PAGE_SIZE);
1070 phdr.p_vaddr = phdr.p_paddr = 0;
1071 phdr.p_filesz = phdr.p_memsz = phdr_sz;
1072 phdr.p_align = 0;
1073
1074 /* Add merged PT_NOTE program header*/
1075 tmp = elfptr + sizeof(Elf32_Ehdr);
1076 memcpy(tmp, &phdr, sizeof(phdr));
1077 tmp += sizeof(phdr);
1078
1079 /* Remove unwanted PT_NOTE program headers. */
1080 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
1081 *elfsz = *elfsz - i;
1082 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
1083 memset(elfptr + *elfsz, 0, i);
1084 *elfsz = roundup(*elfsz, PAGE_SIZE);
1085
1086 /* Modify e_phnum to reflect merged headers. */
1087 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
1088
1089 /* Store the size of all notes. We need this to update the note
1090 * header when the device dumps will be added.
1091 */
1092 elfnotes_orig_sz = phdr.p_memsz;
1093
1094 return 0;
1095}
1096
1097/* Add memory chunks represented by program headers to vmcore list. Also update
1098 * the new offset fields of exported program headers. */
1099static int __init process_ptload_program_headers_elf64(char *elfptr,
1100 size_t elfsz,
1101 size_t elfnotes_sz,
1102 struct list_head *vc_list)
1103{
1104 int i;
1105 Elf64_Ehdr *ehdr_ptr;
1106 Elf64_Phdr *phdr_ptr;
1107 loff_t vmcore_off;
1108 struct vmcore *new;
1109
1110 ehdr_ptr = (Elf64_Ehdr *)elfptr;
1111 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
1112
1113 /* Skip Elf header, program headers and Elf note segment. */
1114 vmcore_off = elfsz + elfnotes_sz;
1115
1116 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1117 u64 paddr, start, end, size;
1118
1119 if (phdr_ptr->p_type != PT_LOAD)
1120 continue;
1121
1122 paddr = phdr_ptr->p_offset;
1123 start = rounddown(paddr, PAGE_SIZE);
1124 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1125 size = end - start;
1126
1127 /* Add this contiguous chunk of memory to vmcore list.*/
1128 new = get_new_element();
1129 if (!new)
1130 return -ENOMEM;
1131 new->paddr = start;
1132 new->size = size;
1133 list_add_tail(&new->list, vc_list);
1134
1135 /* Update the program header offset. */
1136 phdr_ptr->p_offset = vmcore_off + (paddr - start);
1137 vmcore_off = vmcore_off + size;
1138 }
1139 return 0;
1140}
1141
1142static int __init process_ptload_program_headers_elf32(char *elfptr,
1143 size_t elfsz,
1144 size_t elfnotes_sz,
1145 struct list_head *vc_list)
1146{
1147 int i;
1148 Elf32_Ehdr *ehdr_ptr;
1149 Elf32_Phdr *phdr_ptr;
1150 loff_t vmcore_off;
1151 struct vmcore *new;
1152
1153 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1154 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
1155
1156 /* Skip Elf header, program headers and Elf note segment. */
1157 vmcore_off = elfsz + elfnotes_sz;
1158
1159 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1160 u64 paddr, start, end, size;
1161
1162 if (phdr_ptr->p_type != PT_LOAD)
1163 continue;
1164
1165 paddr = phdr_ptr->p_offset;
1166 start = rounddown(paddr, PAGE_SIZE);
1167 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1168 size = end - start;
1169
1170 /* Add this contiguous chunk of memory to vmcore list.*/
1171 new = get_new_element();
1172 if (!new)
1173 return -ENOMEM;
1174 new->paddr = start;
1175 new->size = size;
1176 list_add_tail(&new->list, vc_list);
1177
1178 /* Update the program header offset */
1179 phdr_ptr->p_offset = vmcore_off + (paddr - start);
1180 vmcore_off = vmcore_off + size;
1181 }
1182 return 0;
1183}
1184
1185/* Sets offset fields of vmcore elements. */
1186static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
1187 struct list_head *vc_list)
1188{
1189 loff_t vmcore_off;
1190 struct vmcore *m;
1191
1192 /* Skip Elf header, program headers and Elf note segment. */
1193 vmcore_off = elfsz + elfnotes_sz;
1194
1195 list_for_each_entry(m, vc_list, list) {
1196 m->offset = vmcore_off;
1197 vmcore_off += m->size;
1198 }
1199}
1200
1201static void free_elfcorebuf(void)
1202{
1203 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
1204 elfcorebuf = NULL;
1205 vfree(elfnotes_buf);
1206 elfnotes_buf = NULL;
1207}
1208
1209static int __init parse_crash_elf64_headers(void)
1210{
1211 int rc=0;
1212 Elf64_Ehdr ehdr;
1213 u64 addr;
1214
1215 addr = elfcorehdr_addr;
1216
1217 /* Read Elf header */
1218 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
1219 if (rc < 0)
1220 return rc;
1221
1222 /* Do some basic Verification. */
1223 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
1224 (ehdr.e_type != ET_CORE) ||
1225 !vmcore_elf64_check_arch(&ehdr) ||
1226 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
1227 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
1228 ehdr.e_version != EV_CURRENT ||
1229 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
1230 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
1231 ehdr.e_phnum == 0) {
1232 pr_warn("Warning: Core image elf header is not sane\n");
1233 return -EINVAL;
1234 }
1235
1236 /* Read in all elf headers. */
1237 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
1238 ehdr.e_phnum * sizeof(Elf64_Phdr);
1239 elfcorebuf_sz = elfcorebuf_sz_orig;
1240 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1241 get_order(elfcorebuf_sz_orig));
1242 if (!elfcorebuf)
1243 return -ENOMEM;
1244 addr = elfcorehdr_addr;
1245 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
1246 if (rc < 0)
1247 goto fail;
1248
1249 /* Merge all PT_NOTE headers into one. */
1250 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
1251 &elfnotes_buf, &elfnotes_sz);
1252 if (rc)
1253 goto fail;
1254 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
1255 elfnotes_sz, &vmcore_list);
1256 if (rc)
1257 goto fail;
1258 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1259 return 0;
1260fail:
1261 free_elfcorebuf();
1262 return rc;
1263}
1264
1265static int __init parse_crash_elf32_headers(void)
1266{
1267 int rc=0;
1268 Elf32_Ehdr ehdr;
1269 u64 addr;
1270
1271 addr = elfcorehdr_addr;
1272
1273 /* Read Elf header */
1274 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
1275 if (rc < 0)
1276 return rc;
1277
1278 /* Do some basic Verification. */
1279 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
1280 (ehdr.e_type != ET_CORE) ||
1281 !vmcore_elf32_check_arch(&ehdr) ||
1282 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
1283 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
1284 ehdr.e_version != EV_CURRENT ||
1285 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
1286 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
1287 ehdr.e_phnum == 0) {
1288 pr_warn("Warning: Core image elf header is not sane\n");
1289 return -EINVAL;
1290 }
1291
1292 /* Read in all elf headers. */
1293 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
1294 elfcorebuf_sz = elfcorebuf_sz_orig;
1295 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1296 get_order(elfcorebuf_sz_orig));
1297 if (!elfcorebuf)
1298 return -ENOMEM;
1299 addr = elfcorehdr_addr;
1300 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
1301 if (rc < 0)
1302 goto fail;
1303
1304 /* Merge all PT_NOTE headers into one. */
1305 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
1306 &elfnotes_buf, &elfnotes_sz);
1307 if (rc)
1308 goto fail;
1309 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
1310 elfnotes_sz, &vmcore_list);
1311 if (rc)
1312 goto fail;
1313 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1314 return 0;
1315fail:
1316 free_elfcorebuf();
1317 return rc;
1318}
1319
1320static int __init parse_crash_elf_headers(void)
1321{
1322 unsigned char e_ident[EI_NIDENT];
1323 u64 addr;
1324 int rc=0;
1325
1326 addr = elfcorehdr_addr;
1327 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
1328 if (rc < 0)
1329 return rc;
1330 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
1331 pr_warn("Warning: Core image elf header not found\n");
1332 return -EINVAL;
1333 }
1334
1335 if (e_ident[EI_CLASS] == ELFCLASS64) {
1336 rc = parse_crash_elf64_headers();
1337 if (rc)
1338 return rc;
1339 } else if (e_ident[EI_CLASS] == ELFCLASS32) {
1340 rc = parse_crash_elf32_headers();
1341 if (rc)
1342 return rc;
1343 } else {
1344 pr_warn("Warning: Core image elf header is not sane\n");
1345 return -EINVAL;
1346 }
1347
1348 /* Determine vmcore size. */
1349 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
1350 &vmcore_list);
1351
1352 return 0;
1353}
1354
1355#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
1356/**
1357 * vmcoredd_write_header - Write vmcore device dump header at the
1358 * beginning of the dump's buffer.
1359 * @buf: Output buffer where the note is written
1360 * @data: Dump info
1361 * @size: Size of the dump
1362 *
1363 * Fills beginning of the dump's buffer with vmcore device dump header.
1364 */
1365static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data,
1366 u32 size)
1367{
1368 struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf;
1369
1370 vdd_hdr->n_namesz = sizeof(vdd_hdr->name);
1371 vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name);
1372 vdd_hdr->n_type = NT_VMCOREDD;
1373
1374 strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME,
1375 sizeof(vdd_hdr->name));
1376 memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name));
1377}
1378
1379/**
1380 * vmcoredd_update_program_headers - Update all Elf program headers
1381 * @elfptr: Pointer to elf header
1382 * @elfnotesz: Size of elf notes aligned to page size
1383 * @vmcoreddsz: Size of device dumps to be added to elf note header
1384 *
1385 * Determine type of Elf header (Elf64 or Elf32) and update the elf note size.
1386 * Also update the offsets of all the program headers after the elf note header.
1387 */
1388static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz,
1389 size_t vmcoreddsz)
1390{
1391 unsigned char *e_ident = (unsigned char *)elfptr;
1392 u64 start, end, size;
1393 loff_t vmcore_off;
1394 u32 i;
1395
1396 vmcore_off = elfcorebuf_sz + elfnotesz;
1397
1398 if (e_ident[EI_CLASS] == ELFCLASS64) {
1399 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr;
1400 Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr));
1401
1402 /* Update all program headers */
1403 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
1404 if (phdr->p_type == PT_NOTE) {
1405 /* Update note size */
1406 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
1407 phdr->p_filesz = phdr->p_memsz;
1408 continue;
1409 }
1410
1411 start = rounddown(phdr->p_offset, PAGE_SIZE);
1412 end = roundup(phdr->p_offset + phdr->p_memsz,
1413 PAGE_SIZE);
1414 size = end - start;
1415 phdr->p_offset = vmcore_off + (phdr->p_offset - start);
1416 vmcore_off += size;
1417 }
1418 } else {
1419 Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr;
1420 Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr));
1421
1422 /* Update all program headers */
1423 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
1424 if (phdr->p_type == PT_NOTE) {
1425 /* Update note size */
1426 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
1427 phdr->p_filesz = phdr->p_memsz;
1428 continue;
1429 }
1430
1431 start = rounddown(phdr->p_offset, PAGE_SIZE);
1432 end = roundup(phdr->p_offset + phdr->p_memsz,
1433 PAGE_SIZE);
1434 size = end - start;
1435 phdr->p_offset = vmcore_off + (phdr->p_offset - start);
1436 vmcore_off += size;
1437 }
1438 }
1439}
1440
1441/**
1442 * vmcoredd_update_size - Update the total size of the device dumps and update
1443 * Elf header
1444 * @dump_size: Size of the current device dump to be added to total size
1445 *
1446 * Update the total size of all the device dumps and update the Elf program
1447 * headers. Calculate the new offsets for the vmcore list and update the
1448 * total vmcore size.
1449 */
1450static void vmcoredd_update_size(size_t dump_size)
1451{
1452 vmcoredd_orig_sz += dump_size;
1453 elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz;
1454 vmcoredd_update_program_headers(elfcorebuf, elfnotes_sz,
1455 vmcoredd_orig_sz);
1456
1457 /* Update vmcore list offsets */
1458 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1459
1460 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
1461 &vmcore_list);
1462 proc_vmcore->size = vmcore_size;
1463}
1464
1465/**
1466 * vmcore_add_device_dump - Add a buffer containing device dump to vmcore
1467 * @data: dump info.
1468 *
1469 * Allocate a buffer and invoke the calling driver's dump collect routine.
1470 * Write Elf note at the beginning of the buffer to indicate vmcore device
1471 * dump and add the dump to global list.
1472 */
1473int vmcore_add_device_dump(struct vmcoredd_data *data)
1474{
1475 struct vmcoredd_node *dump;
1476 void *buf = NULL;
1477 size_t data_size;
1478 int ret;
1479
1480 if (vmcoredd_disabled) {
1481 pr_err_once("Device dump is disabled\n");
1482 return -EINVAL;
1483 }
1484
1485 if (!data || !strlen(data->dump_name) ||
1486 !data->vmcoredd_callback || !data->size)
1487 return -EINVAL;
1488
1489 dump = vzalloc(sizeof(*dump));
1490 if (!dump) {
1491 ret = -ENOMEM;
1492 goto out_err;
1493 }
1494
1495 /* Keep size of the buffer page aligned so that it can be mmaped */
1496 data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
1497 PAGE_SIZE);
1498
1499 /* Allocate buffer for driver's to write their dumps */
1500 buf = vmcore_alloc_buf(data_size);
1501 if (!buf) {
1502 ret = -ENOMEM;
1503 goto out_err;
1504 }
1505
1506 vmcoredd_write_header(buf, data, data_size -
1507 sizeof(struct vmcoredd_header));
1508
1509 /* Invoke the driver's dump collection routing */
1510 ret = data->vmcoredd_callback(data, buf +
1511 sizeof(struct vmcoredd_header));
1512 if (ret)
1513 goto out_err;
1514
1515 dump->buf = buf;
1516 dump->size = data_size;
1517
1518 /* Add the dump to driver sysfs list */
1519 mutex_lock(&vmcoredd_mutex);
1520 list_add_tail(&dump->list, &vmcoredd_list);
1521 mutex_unlock(&vmcoredd_mutex);
1522
1523 vmcoredd_update_size(data_size);
1524 return 0;
1525
1526out_err:
1527 vfree(buf);
1528 vfree(dump);
1529
1530 return ret;
1531}
1532EXPORT_SYMBOL(vmcore_add_device_dump);
1533#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1534
1535/* Free all dumps in vmcore device dump list */
1536static void vmcore_free_device_dumps(void)
1537{
1538#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
1539 mutex_lock(&vmcoredd_mutex);
1540 while (!list_empty(&vmcoredd_list)) {
1541 struct vmcoredd_node *dump;
1542
1543 dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node,
1544 list);
1545 list_del(&dump->list);
1546 vfree(dump->buf);
1547 vfree(dump);
1548 }
1549 mutex_unlock(&vmcoredd_mutex);
1550#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1551}
1552
1553/* Init function for vmcore module. */
1554static int __init vmcore_init(void)
1555{
1556 int rc = 0;
1557
1558 /* Allow architectures to allocate ELF header in 2nd kernel */
1559 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
1560 if (rc)
1561 return rc;
1562 /*
1563 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
1564 * then capture the dump.
1565 */
1566 if (!(is_vmcore_usable()))
1567 return rc;
1568 rc = parse_crash_elf_headers();
1569 if (rc) {
1570 elfcorehdr_free(elfcorehdr_addr);
1571 pr_warn("Kdump: vmcore not initialized\n");
1572 return rc;
1573 }
1574 elfcorehdr_free(elfcorehdr_addr);
1575 elfcorehdr_addr = ELFCORE_ADDR_ERR;
1576
1577 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops);
1578 if (proc_vmcore)
1579 proc_vmcore->size = vmcore_size;
1580 return 0;
1581}
1582fs_initcall(vmcore_init);
1583
1584/* Cleanup function for vmcore module. */
1585void vmcore_cleanup(void)
1586{
1587 if (proc_vmcore) {
1588 proc_remove(proc_vmcore);
1589 proc_vmcore = NULL;
1590 }
1591
1592 /* clear the vmcore list. */
1593 while (!list_empty(&vmcore_list)) {
1594 struct vmcore *m;
1595
1596 m = list_first_entry(&vmcore_list, struct vmcore, list);
1597 list_del(&m->list);
1598 kfree(m);
1599 }
1600 free_elfcorebuf();
1601
1602 /* clear vmcore device dump list */
1603 vmcore_free_device_dumps();
1604}
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 */
36static LIST_HEAD(vmcore_list);
37
38/* Stores the pointer to the buffer containing kernel elf core headers. */
39static char *elfcorebuf;
40static size_t elfcorebuf_sz;
41static size_t elfcorebuf_sz_orig;
42
43static char *elfnotes_buf;
44static size_t elfnotes_sz;
45/* Size of all notes minus the device dump notes */
46static size_t elfnotes_orig_sz;
47
48/* Total size of vmcore file. */
49static u64 vmcore_size;
50
51static 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 */
55static LIST_HEAD(vmcoredd_list);
56static DEFINE_MUTEX(vmcoredd_mutex);
57
58static bool vmcoredd_disabled;
59core_param(novmcoredd, vmcoredd_disabled, bool, 0);
60#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
61
62/* Device Dump Size */
63static size_t vmcoredd_orig_sz;
64
65static DEFINE_SPINLOCK(vmcore_cb_lock);
66DEFINE_STATIC_SRCU(vmcore_cb_srcu);
67/* List of registered vmcore callbacks. */
68static LIST_HEAD(vmcore_cb_list);
69/* Whether the vmcore has been opened once. */
70static bool vmcore_opened;
71
72void register_vmcore_cb(struct vmcore_cb *cb)
73{
74 INIT_LIST_HEAD(&cb->next);
75 spin_lock(&vmcore_cb_lock);
76 list_add_tail(&cb->next, &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(&vmcore_cb_lock);
84}
85EXPORT_SYMBOL_GPL(register_vmcore_cb);
86
87void unregister_vmcore_cb(struct vmcore_cb *cb)
88{
89 spin_lock(&vmcore_cb_lock);
90 list_del_rcu(&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(&vmcore_cb_lock);
99
100 synchronize_srcu(&vmcore_cb_srcu);
101}
102EXPORT_SYMBOL_GPL(unregister_vmcore_cb);
103
104static 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
121static int open_vmcore(struct inode *inode, struct file *file)
122{
123 spin_lock(&vmcore_cb_lock);
124 vmcore_opened = true;
125 spin_unlock(&vmcore_cb_lock);
126
127 return 0;
128}
129
130/* Reads a page from the oldmem device from given offset. */
131ssize_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(&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(nr_bytes, iter);
155 } else {
156 if (encrypted)
157 tmp = copy_oldmem_page_encrypted(iter, pfn,
158 nr_bytes,
159 offset);
160 else
161 tmp = copy_oldmem_page(iter, pfn, nr_bytes,
162 offset);
163 }
164 if (tmp < nr_bytes) {
165 srcu_read_unlock(&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(&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 */
183int __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 */
191void __weak elfcorehdr_free(unsigned long long addr)
192{}
193
194/*
195 * Architectures may override this function to read from ELF header
196 */
197ssize_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(&iter, ITER_DEST, &kvec, 1, count);
203
204 return read_from_oldmem(&iter, count, ppos, false);
205}
206
207/*
208 * Architectures may override this function to read from notes sections
209 */
210ssize_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(&iter, ITER_DEST, &kvec, 1, count);
216
217 return read_from_oldmem(&iter, count, ppos,
218 cc_platform_has(CC_ATTR_MEM_ENCRYPT));
219}
220
221/*
222 * Architectures may override this function to map oldmem
223 */
224int __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, from, pfn, size, prot);
230}
231
232/*
233 * Architectures which support memory encryption override this.
234 */
235ssize_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(iter, pfn, csize, offset);
239}
240
241#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
242static 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(buf, tsz, 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
270out_unlock:
271 mutex_unlock(&vmcoredd_mutex);
272 return ret;
273}
274
275#ifdef CONFIG_MMU
276static 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, dst, buf, 0,
291 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
307out_unlock:
308 mutex_unlock(&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 */
317static 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(iter) || *fpos >= vmcore_size)
325 return 0;
326
327 iov_iter_truncate(iter, 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(elfcorebuf + *fpos, tsz, iter) < tsz)
333 return -EFAULT;
334 *fpos += tsz;
335 acc += tsz;
336
337 /* leave now if filled buffer already */
338 if (!iov_iter_count(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, tsz))
362 return -EFAULT;
363
364 *fpos += tsz;
365 acc += tsz;
366
367 /* leave now if filled buffer already */
368 if (!iov_iter_count(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(kaddr, tsz, 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(iter))
385 return acc;
386
387 cond_resched();
388 }
389
390 list_for_each_entry(m, &vmcore_list, list) {
391 if (*fpos < m->offset + m->size) {
392 tsz = (size_t)min_t(unsigned long long,
393 m->offset + m->size - *fpos,
394 iov_iter_count(iter));
395 start = m->paddr + *fpos - m->offset;
396 tmp = read_from_oldmem(iter, tsz, &start,
397 cc_platform_has(CC_ATTR_MEM_ENCRYPT));
398 if (tmp < 0)
399 return tmp;
400 *fpos += tsz;
401 acc += tsz;
402
403 /* leave now if filled buffer already */
404 if (!iov_iter_count(iter))
405 return acc;
406 }
407
408 cond_resched();
409 }
410
411 return acc;
412}
413
414static ssize_t read_vmcore(struct kiocb *iocb, struct iov_iter *iter)
415{
416 return __read_vmcore(iter, &iocb->ki_pos);
417}
418
419/**
420 * vmcore_alloc_buf - allocate buffer in vmalloc memory
421 * @size: size of buffer
422 *
423 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
424 * the buffer to user-space by means of remap_vmalloc_range().
425 *
426 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
427 * disabled and there's no need to allow users to mmap the buffer.
428 */
429static inline char *vmcore_alloc_buf(size_t size)
430{
431#ifdef CONFIG_MMU
432 return vmalloc_user(size);
433#else
434 return vzalloc(size);
435#endif
436}
437
438/*
439 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
440 * essential for mmap_vmcore() in order to map physically
441 * non-contiguous objects (ELF header, ELF note segment and memory
442 * regions in the 1st kernel pointed to by PT_LOAD entries) into
443 * virtually contiguous user-space in ELF layout.
444 */
445#ifdef CONFIG_MMU
446
447/*
448 * The vmcore fault handler uses the page cache and fills data using the
449 * standard __read_vmcore() function.
450 *
451 * On s390 the fault handler is used for memory regions that can't be mapped
452 * directly with remap_pfn_range().
453 */
454static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
455{
456#ifdef CONFIG_S390
457 struct address_space *mapping = vmf->vma->vm_file->f_mapping;
458 pgoff_t index = vmf->pgoff;
459 struct iov_iter iter;
460 struct kvec kvec;
461 struct page *page;
462 loff_t offset;
463 int rc;
464
465 page = find_or_create_page(mapping, index, GFP_KERNEL);
466 if (!page)
467 return VM_FAULT_OOM;
468 if (!PageUptodate(page)) {
469 offset = (loff_t) index << PAGE_SHIFT;
470 kvec.iov_base = page_address(page);
471 kvec.iov_len = PAGE_SIZE;
472 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, PAGE_SIZE);
473
474 rc = __read_vmcore(&iter, &offset);
475 if (rc < 0) {
476 unlock_page(page);
477 put_page(page);
478 return vmf_error(rc);
479 }
480 SetPageUptodate(page);
481 }
482 unlock_page(page);
483 vmf->page = page;
484 return 0;
485#else
486 return VM_FAULT_SIGBUS;
487#endif
488}
489
490static const struct vm_operations_struct vmcore_mmap_ops = {
491 .fault = mmap_vmcore_fault,
492};
493
494/*
495 * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages
496 * reported as not being ram with the zero page.
497 *
498 * @vma: vm_area_struct describing requested mapping
499 * @from: start remapping from
500 * @pfn: page frame number to start remapping to
501 * @size: remapping size
502 * @prot: protection bits
503 *
504 * Returns zero on success, -EAGAIN on failure.
505 */
506static int remap_oldmem_pfn_checked(struct vm_area_struct *vma,
507 unsigned long from, unsigned long pfn,
508 unsigned long size, pgprot_t prot)
509{
510 unsigned long map_size;
511 unsigned long pos_start, pos_end, pos;
512 unsigned long zeropage_pfn = my_zero_pfn(0);
513 size_t len = 0;
514
515 pos_start = pfn;
516 pos_end = pfn + (size >> PAGE_SHIFT);
517
518 for (pos = pos_start; pos < pos_end; ++pos) {
519 if (!pfn_is_ram(pos)) {
520 /*
521 * We hit a page which is not ram. Remap the continuous
522 * region between pos_start and pos-1 and replace
523 * the non-ram page at pos with the zero page.
524 */
525 if (pos > pos_start) {
526 /* Remap continuous region */
527 map_size = (pos - pos_start) << PAGE_SHIFT;
528 if (remap_oldmem_pfn_range(vma, from + len,
529 pos_start, map_size,
530 prot))
531 goto fail;
532 len += map_size;
533 }
534 /* Remap the zero page */
535 if (remap_oldmem_pfn_range(vma, from + len,
536 zeropage_pfn,
537 PAGE_SIZE, prot))
538 goto fail;
539 len += PAGE_SIZE;
540 pos_start = pos + 1;
541 }
542 }
543 if (pos > pos_start) {
544 /* Remap the rest */
545 map_size = (pos - pos_start) << PAGE_SHIFT;
546 if (remap_oldmem_pfn_range(vma, from + len, pos_start,
547 map_size, prot))
548 goto fail;
549 }
550 return 0;
551fail:
552 do_munmap(vma->vm_mm, from, len, NULL);
553 return -EAGAIN;
554}
555
556static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,
557 unsigned long from, unsigned long pfn,
558 unsigned long size, pgprot_t prot)
559{
560 int ret, idx;
561
562 /*
563 * Check if a callback was registered to avoid looping over all
564 * pages without a reason.
565 */
566 idx = srcu_read_lock(&vmcore_cb_srcu);
567 if (!list_empty(&vmcore_cb_list))
568 ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
569 else
570 ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot);
571 srcu_read_unlock(&vmcore_cb_srcu, idx);
572 return ret;
573}
574
575static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
576{
577 size_t size = vma->vm_end - vma->vm_start;
578 u64 start, end, len, tsz;
579 struct vmcore *m;
580
581 start = (u64)vma->vm_pgoff << PAGE_SHIFT;
582 end = start + size;
583
584 if (size > vmcore_size || end > vmcore_size)
585 return -EINVAL;
586
587 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
588 return -EPERM;
589
590 vm_flags_mod(vma, VM_MIXEDMAP, VM_MAYWRITE | VM_MAYEXEC);
591 vma->vm_ops = &vmcore_mmap_ops;
592
593 len = 0;
594
595 if (start < elfcorebuf_sz) {
596 u64 pfn;
597
598 tsz = min(elfcorebuf_sz - (size_t)start, size);
599 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
600 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
601 vma->vm_page_prot))
602 return -EAGAIN;
603 size -= tsz;
604 start += tsz;
605 len += tsz;
606
607 if (size == 0)
608 return 0;
609 }
610
611 if (start < elfcorebuf_sz + elfnotes_sz) {
612 void *kaddr;
613
614 /* We add device dumps before other elf notes because the
615 * other elf notes may not fill the elf notes buffer
616 * completely and we will end up with zero-filled data
617 * between the elf notes and the device dumps. Tools will
618 * then try to decode this zero-filled data as valid notes
619 * and we don't want that. Hence, adding device dumps before
620 * the other elf notes ensure that zero-filled data can be
621 * avoided. This also ensures that the device dumps and
622 * other elf notes can be properly mmaped at page aligned
623 * address.
624 */
625#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
626 /* Read device dumps */
627 if (start < elfcorebuf_sz + vmcoredd_orig_sz) {
628 u64 start_off;
629
630 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
631 (size_t)start, size);
632 start_off = start - elfcorebuf_sz;
633 if (vmcoredd_mmap_dumps(vma, vma->vm_start + len,
634 start_off, tsz))
635 goto fail;
636
637 size -= tsz;
638 start += tsz;
639 len += tsz;
640
641 /* leave now if filled buffer already */
642 if (!size)
643 return 0;
644 }
645#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
646
647 /* Read remaining elf notes */
648 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
649 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz;
650 if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
651 kaddr, 0, tsz))
652 goto fail;
653
654 size -= tsz;
655 start += tsz;
656 len += tsz;
657
658 if (size == 0)
659 return 0;
660 }
661
662 list_for_each_entry(m, &vmcore_list, list) {
663 if (start < m->offset + m->size) {
664 u64 paddr = 0;
665
666 tsz = (size_t)min_t(unsigned long long,
667 m->offset + m->size - start, size);
668 paddr = m->paddr + start - m->offset;
669 if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len,
670 paddr >> PAGE_SHIFT, tsz,
671 vma->vm_page_prot))
672 goto fail;
673 size -= tsz;
674 start += tsz;
675 len += tsz;
676
677 if (size == 0)
678 return 0;
679 }
680 }
681
682 return 0;
683fail:
684 do_munmap(vma->vm_mm, vma->vm_start, len, NULL);
685 return -EAGAIN;
686}
687#else
688static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
689{
690 return -ENOSYS;
691}
692#endif
693
694static const struct proc_ops vmcore_proc_ops = {
695 .proc_open = open_vmcore,
696 .proc_read_iter = read_vmcore,
697 .proc_lseek = default_llseek,
698 .proc_mmap = mmap_vmcore,
699};
700
701static struct vmcore* __init get_new_element(void)
702{
703 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
704}
705
706static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
707 struct list_head *vc_list)
708{
709 u64 size;
710 struct vmcore *m;
711
712 size = elfsz + elfnotesegsz;
713 list_for_each_entry(m, vc_list, list) {
714 size += m->size;
715 }
716 return size;
717}
718
719/**
720 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
721 *
722 * @ehdr_ptr: ELF header
723 *
724 * This function updates p_memsz member of each PT_NOTE entry in the
725 * program header table pointed to by @ehdr_ptr to real size of ELF
726 * note segment.
727 */
728static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
729{
730 int i, rc=0;
731 Elf64_Phdr *phdr_ptr;
732 Elf64_Nhdr *nhdr_ptr;
733
734 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
735 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
736 void *notes_section;
737 u64 offset, max_sz, sz, real_sz = 0;
738 if (phdr_ptr->p_type != PT_NOTE)
739 continue;
740 max_sz = phdr_ptr->p_memsz;
741 offset = phdr_ptr->p_offset;
742 notes_section = kmalloc(max_sz, GFP_KERNEL);
743 if (!notes_section)
744 return -ENOMEM;
745 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
746 if (rc < 0) {
747 kfree(notes_section);
748 return rc;
749 }
750 nhdr_ptr = notes_section;
751 while (nhdr_ptr->n_namesz != 0) {
752 sz = sizeof(Elf64_Nhdr) +
753 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
754 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
755 if ((real_sz + sz) > max_sz) {
756 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
757 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
758 break;
759 }
760 real_sz += sz;
761 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
762 }
763 kfree(notes_section);
764 phdr_ptr->p_memsz = real_sz;
765 if (real_sz == 0) {
766 pr_warn("Warning: Zero PT_NOTE entries found\n");
767 }
768 }
769
770 return 0;
771}
772
773/**
774 * get_note_number_and_size_elf64 - get the number of PT_NOTE program
775 * headers and sum of real size of their ELF note segment headers and
776 * data.
777 *
778 * @ehdr_ptr: ELF header
779 * @nr_ptnote: buffer for the number of PT_NOTE program headers
780 * @sz_ptnote: buffer for size of unique PT_NOTE program header
781 *
782 * This function is used to merge multiple PT_NOTE program headers
783 * into a unique single one. The resulting unique entry will have
784 * @sz_ptnote in its phdr->p_mem.
785 *
786 * It is assumed that program headers with PT_NOTE type pointed to by
787 * @ehdr_ptr has already been updated by update_note_header_size_elf64
788 * and each of PT_NOTE program headers has actual ELF note segment
789 * size in its p_memsz member.
790 */
791static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
792 int *nr_ptnote, u64 *sz_ptnote)
793{
794 int i;
795 Elf64_Phdr *phdr_ptr;
796
797 *nr_ptnote = *sz_ptnote = 0;
798
799 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
800 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
801 if (phdr_ptr->p_type != PT_NOTE)
802 continue;
803 *nr_ptnote += 1;
804 *sz_ptnote += phdr_ptr->p_memsz;
805 }
806
807 return 0;
808}
809
810/**
811 * copy_notes_elf64 - copy ELF note segments in a given buffer
812 *
813 * @ehdr_ptr: ELF header
814 * @notes_buf: buffer into which ELF note segments are copied
815 *
816 * This function is used to copy ELF note segment in the 1st kernel
817 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
818 * size of the buffer @notes_buf is equal to or larger than sum of the
819 * real ELF note segment headers and data.
820 *
821 * It is assumed that program headers with PT_NOTE type pointed to by
822 * @ehdr_ptr has already been updated by update_note_header_size_elf64
823 * and each of PT_NOTE program headers has actual ELF note segment
824 * size in its p_memsz member.
825 */
826static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
827{
828 int i, rc=0;
829 Elf64_Phdr *phdr_ptr;
830
831 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
832
833 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
834 u64 offset;
835 if (phdr_ptr->p_type != PT_NOTE)
836 continue;
837 offset = phdr_ptr->p_offset;
838 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
839 &offset);
840 if (rc < 0)
841 return rc;
842 notes_buf += phdr_ptr->p_memsz;
843 }
844
845 return 0;
846}
847
848/* Merges all the PT_NOTE headers into one. */
849static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
850 char **notes_buf, size_t *notes_sz)
851{
852 int i, nr_ptnote=0, rc=0;
853 char *tmp;
854 Elf64_Ehdr *ehdr_ptr;
855 Elf64_Phdr phdr;
856 u64 phdr_sz = 0, note_off;
857
858 ehdr_ptr = (Elf64_Ehdr *)elfptr;
859
860 rc = update_note_header_size_elf64(ehdr_ptr);
861 if (rc < 0)
862 return rc;
863
864 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
865 if (rc < 0)
866 return rc;
867
868 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
869 *notes_buf = vmcore_alloc_buf(*notes_sz);
870 if (!*notes_buf)
871 return -ENOMEM;
872
873 rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
874 if (rc < 0)
875 return rc;
876
877 /* Prepare merged PT_NOTE program header. */
878 phdr.p_type = PT_NOTE;
879 phdr.p_flags = 0;
880 note_off = sizeof(Elf64_Ehdr) +
881 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
882 phdr.p_offset = roundup(note_off, PAGE_SIZE);
883 phdr.p_vaddr = phdr.p_paddr = 0;
884 phdr.p_filesz = phdr.p_memsz = phdr_sz;
885 phdr.p_align = 4;
886
887 /* Add merged PT_NOTE program header*/
888 tmp = elfptr + sizeof(Elf64_Ehdr);
889 memcpy(tmp, &phdr, sizeof(phdr));
890 tmp += sizeof(phdr);
891
892 /* Remove unwanted PT_NOTE program headers. */
893 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
894 *elfsz = *elfsz - i;
895 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
896 memset(elfptr + *elfsz, 0, i);
897 *elfsz = roundup(*elfsz, PAGE_SIZE);
898
899 /* Modify e_phnum to reflect merged headers. */
900 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
901
902 /* Store the size of all notes. We need this to update the note
903 * header when the device dumps will be added.
904 */
905 elfnotes_orig_sz = phdr.p_memsz;
906
907 return 0;
908}
909
910/**
911 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
912 *
913 * @ehdr_ptr: ELF header
914 *
915 * This function updates p_memsz member of each PT_NOTE entry in the
916 * program header table pointed to by @ehdr_ptr to real size of ELF
917 * note segment.
918 */
919static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
920{
921 int i, rc=0;
922 Elf32_Phdr *phdr_ptr;
923 Elf32_Nhdr *nhdr_ptr;
924
925 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
926 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
927 void *notes_section;
928 u64 offset, max_sz, sz, real_sz = 0;
929 if (phdr_ptr->p_type != PT_NOTE)
930 continue;
931 max_sz = phdr_ptr->p_memsz;
932 offset = phdr_ptr->p_offset;
933 notes_section = kmalloc(max_sz, GFP_KERNEL);
934 if (!notes_section)
935 return -ENOMEM;
936 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
937 if (rc < 0) {
938 kfree(notes_section);
939 return rc;
940 }
941 nhdr_ptr = notes_section;
942 while (nhdr_ptr->n_namesz != 0) {
943 sz = sizeof(Elf32_Nhdr) +
944 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
945 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
946 if ((real_sz + sz) > max_sz) {
947 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
948 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
949 break;
950 }
951 real_sz += sz;
952 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
953 }
954 kfree(notes_section);
955 phdr_ptr->p_memsz = real_sz;
956 if (real_sz == 0) {
957 pr_warn("Warning: Zero PT_NOTE entries found\n");
958 }
959 }
960
961 return 0;
962}
963
964/**
965 * get_note_number_and_size_elf32 - get the number of PT_NOTE program
966 * headers and sum of real size of their ELF note segment headers and
967 * data.
968 *
969 * @ehdr_ptr: ELF header
970 * @nr_ptnote: buffer for the number of PT_NOTE program headers
971 * @sz_ptnote: buffer for size of unique PT_NOTE program header
972 *
973 * This function is used to merge multiple PT_NOTE program headers
974 * into a unique single one. The resulting unique entry will have
975 * @sz_ptnote in its phdr->p_mem.
976 *
977 * It is assumed that program headers with PT_NOTE type pointed to by
978 * @ehdr_ptr has already been updated by update_note_header_size_elf32
979 * and each of PT_NOTE program headers has actual ELF note segment
980 * size in its p_memsz member.
981 */
982static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
983 int *nr_ptnote, u64 *sz_ptnote)
984{
985 int i;
986 Elf32_Phdr *phdr_ptr;
987
988 *nr_ptnote = *sz_ptnote = 0;
989
990 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
991 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
992 if (phdr_ptr->p_type != PT_NOTE)
993 continue;
994 *nr_ptnote += 1;
995 *sz_ptnote += phdr_ptr->p_memsz;
996 }
997
998 return 0;
999}
1000
1001/**
1002 * copy_notes_elf32 - copy ELF note segments in a given buffer
1003 *
1004 * @ehdr_ptr: ELF header
1005 * @notes_buf: buffer into which ELF note segments are copied
1006 *
1007 * This function is used to copy ELF note segment in the 1st kernel
1008 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
1009 * size of the buffer @notes_buf is equal to or larger than sum of the
1010 * real ELF note segment headers and data.
1011 *
1012 * It is assumed that program headers with PT_NOTE type pointed to by
1013 * @ehdr_ptr has already been updated by update_note_header_size_elf32
1014 * and each of PT_NOTE program headers has actual ELF note segment
1015 * size in its p_memsz member.
1016 */
1017static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
1018{
1019 int i, rc=0;
1020 Elf32_Phdr *phdr_ptr;
1021
1022 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
1023
1024 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1025 u64 offset;
1026 if (phdr_ptr->p_type != PT_NOTE)
1027 continue;
1028 offset = phdr_ptr->p_offset;
1029 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
1030 &offset);
1031 if (rc < 0)
1032 return rc;
1033 notes_buf += phdr_ptr->p_memsz;
1034 }
1035
1036 return 0;
1037}
1038
1039/* Merges all the PT_NOTE headers into one. */
1040static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
1041 char **notes_buf, size_t *notes_sz)
1042{
1043 int i, nr_ptnote=0, rc=0;
1044 char *tmp;
1045 Elf32_Ehdr *ehdr_ptr;
1046 Elf32_Phdr phdr;
1047 u64 phdr_sz = 0, note_off;
1048
1049 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1050
1051 rc = update_note_header_size_elf32(ehdr_ptr);
1052 if (rc < 0)
1053 return rc;
1054
1055 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
1056 if (rc < 0)
1057 return rc;
1058
1059 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
1060 *notes_buf = vmcore_alloc_buf(*notes_sz);
1061 if (!*notes_buf)
1062 return -ENOMEM;
1063
1064 rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
1065 if (rc < 0)
1066 return rc;
1067
1068 /* Prepare merged PT_NOTE program header. */
1069 phdr.p_type = PT_NOTE;
1070 phdr.p_flags = 0;
1071 note_off = sizeof(Elf32_Ehdr) +
1072 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
1073 phdr.p_offset = roundup(note_off, PAGE_SIZE);
1074 phdr.p_vaddr = phdr.p_paddr = 0;
1075 phdr.p_filesz = phdr.p_memsz = phdr_sz;
1076 phdr.p_align = 4;
1077
1078 /* Add merged PT_NOTE program header*/
1079 tmp = elfptr + sizeof(Elf32_Ehdr);
1080 memcpy(tmp, &phdr, sizeof(phdr));
1081 tmp += sizeof(phdr);
1082
1083 /* Remove unwanted PT_NOTE program headers. */
1084 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
1085 *elfsz = *elfsz - i;
1086 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
1087 memset(elfptr + *elfsz, 0, i);
1088 *elfsz = roundup(*elfsz, PAGE_SIZE);
1089
1090 /* Modify e_phnum to reflect merged headers. */
1091 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
1092
1093 /* Store the size of all notes. We need this to update the note
1094 * header when the device dumps will be added.
1095 */
1096 elfnotes_orig_sz = phdr.p_memsz;
1097
1098 return 0;
1099}
1100
1101/* Add memory chunks represented by program headers to vmcore list. Also update
1102 * the new offset fields of exported program headers. */
1103static int __init process_ptload_program_headers_elf64(char *elfptr,
1104 size_t elfsz,
1105 size_t elfnotes_sz,
1106 struct list_head *vc_list)
1107{
1108 int i;
1109 Elf64_Ehdr *ehdr_ptr;
1110 Elf64_Phdr *phdr_ptr;
1111 loff_t vmcore_off;
1112 struct vmcore *new;
1113
1114 ehdr_ptr = (Elf64_Ehdr *)elfptr;
1115 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
1116
1117 /* Skip ELF header, program headers and ELF note segment. */
1118 vmcore_off = elfsz + elfnotes_sz;
1119
1120 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1121 u64 paddr, start, end, size;
1122
1123 if (phdr_ptr->p_type != PT_LOAD)
1124 continue;
1125
1126 paddr = phdr_ptr->p_offset;
1127 start = rounddown(paddr, PAGE_SIZE);
1128 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1129 size = end - start;
1130
1131 /* Add this contiguous chunk of memory to vmcore list.*/
1132 new = get_new_element();
1133 if (!new)
1134 return -ENOMEM;
1135 new->paddr = start;
1136 new->size = size;
1137 list_add_tail(&new->list, vc_list);
1138
1139 /* Update the program header offset. */
1140 phdr_ptr->p_offset = vmcore_off + (paddr - start);
1141 vmcore_off = vmcore_off + size;
1142 }
1143 return 0;
1144}
1145
1146static int __init process_ptload_program_headers_elf32(char *elfptr,
1147 size_t elfsz,
1148 size_t elfnotes_sz,
1149 struct list_head *vc_list)
1150{
1151 int i;
1152 Elf32_Ehdr *ehdr_ptr;
1153 Elf32_Phdr *phdr_ptr;
1154 loff_t vmcore_off;
1155 struct vmcore *new;
1156
1157 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1158 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
1159
1160 /* Skip ELF header, program headers and ELF note segment. */
1161 vmcore_off = elfsz + elfnotes_sz;
1162
1163 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1164 u64 paddr, start, end, size;
1165
1166 if (phdr_ptr->p_type != PT_LOAD)
1167 continue;
1168
1169 paddr = phdr_ptr->p_offset;
1170 start = rounddown(paddr, PAGE_SIZE);
1171 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1172 size = end - start;
1173
1174 /* Add this contiguous chunk of memory to vmcore list.*/
1175 new = get_new_element();
1176 if (!new)
1177 return -ENOMEM;
1178 new->paddr = start;
1179 new->size = size;
1180 list_add_tail(&new->list, vc_list);
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 loff_t vmcore_off;
1194 struct vmcore *m;
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((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
1208 elfcorebuf = NULL;
1209 vfree(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((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
1223 if (rc < 0)
1224 return rc;
1225
1226 /* Do some basic Verification. */
1227 if (memcmp(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(elfcorebuf, elfcorebuf_sz_orig, &addr);
1250 if (rc < 0)
1251 goto fail;
1252
1253 /* Merge all PT_NOTE headers into one. */
1254 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
1255 &elfnotes_buf, &elfnotes_sz);
1256 if (rc)
1257 goto fail;
1258 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
1259 elfnotes_sz, &vmcore_list);
1260 if (rc)
1261 goto fail;
1262 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &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((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
1279 if (rc < 0)
1280 return rc;
1281
1282 /* Do some basic Verification. */
1283 if (memcmp(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(elfcorebuf, elfcorebuf_sz_orig, &addr);
1305 if (rc < 0)
1306 goto fail;
1307
1308 /* Merge all PT_NOTE headers into one. */
1309 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
1310 &elfnotes_buf, &elfnotes_sz);
1311 if (rc)
1312 goto fail;
1313 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
1314 elfnotes_sz, &vmcore_list);
1315 if (rc)
1316 goto fail;
1317 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &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(e_ident, EI_NIDENT, &addr);
1332 if (rc < 0)
1333 return rc;
1334 if (memcmp(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(elfcorebuf_sz, elfnotes_sz,
1354 &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(elfcorebuf, elfnotes_sz,
1458 vmcoredd_orig_sz);
1459
1460 /* Update vmcore list offsets */
1461 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1462
1463 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
1464 &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 ret = -ENOMEM;
1495 goto out_err;
1496 }
1497
1498 /* Keep size of the buffer page aligned so that it can be mmaped */
1499 data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
1500 PAGE_SIZE);
1501
1502 /* Allocate buffer for driver's to write their dumps */
1503 buf = vmcore_alloc_buf(data_size);
1504 if (!buf) {
1505 ret = -ENOMEM;
1506 goto out_err;
1507 }
1508
1509 vmcoredd_write_header(buf, data, data_size -
1510 sizeof(struct vmcoredd_header));
1511
1512 /* Invoke the driver's dump collection routing */
1513 ret = data->vmcoredd_callback(data, buf +
1514 sizeof(struct vmcoredd_header));
1515 if (ret)
1516 goto out_err;
1517
1518 dump->buf = buf;
1519 dump->size = data_size;
1520
1521 /* Add the dump to driver sysfs list */
1522 mutex_lock(&vmcoredd_mutex);
1523 list_add_tail(&dump->list, &vmcoredd_list);
1524 mutex_unlock(&vmcoredd_mutex);
1525
1526 vmcoredd_update_size(data_size);
1527 return 0;
1528
1529out_err:
1530 vfree(buf);
1531 vfree(dump);
1532
1533 return ret;
1534}
1535EXPORT_SYMBOL(vmcore_add_device_dump);
1536#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1537
1538/* Free all dumps in vmcore device dump list */
1539static void vmcore_free_device_dumps(void)
1540{
1541#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
1542 mutex_lock(&vmcoredd_mutex);
1543 while (!list_empty(&vmcoredd_list)) {
1544 struct vmcoredd_node *dump;
1545
1546 dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node,
1547 list);
1548 list_del(&dump->list);
1549 vfree(dump->buf);
1550 vfree(dump);
1551 }
1552 mutex_unlock(&vmcoredd_mutex);
1553#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1554}
1555
1556/* Init function for vmcore module. */
1557static int __init vmcore_init(void)
1558{
1559 int rc = 0;
1560
1561 /* Allow architectures to allocate ELF header in 2nd kernel */
1562 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
1563 if (rc)
1564 return rc;
1565 /*
1566 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
1567 * then capture the dump.
1568 */
1569 if (!(is_vmcore_usable()))
1570 return rc;
1571 rc = parse_crash_elf_headers();
1572 if (rc) {
1573 elfcorehdr_free(elfcorehdr_addr);
1574 pr_warn("Kdump: vmcore not initialized\n");
1575 return rc;
1576 }
1577 elfcorehdr_free(elfcorehdr_addr);
1578 elfcorehdr_addr = ELFCORE_ADDR_ERR;
1579
1580 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &vmcore_proc_ops);
1581 if (proc_vmcore)
1582 proc_vmcore->size = vmcore_size;
1583 return 0;
1584}
1585fs_initcall(vmcore_init);
1586
1587/* Cleanup function for vmcore module. */
1588void vmcore_cleanup(void)
1589{
1590 if (proc_vmcore) {
1591 proc_remove(proc_vmcore);
1592 proc_vmcore = NULL;
1593 }
1594
1595 /* clear the vmcore list. */
1596 while (!list_empty(&vmcore_list)) {
1597 struct vmcore *m;
1598
1599 m = list_first_entry(&vmcore_list, struct vmcore, list);
1600 list_del(&m->list);
1601 kfree(m);
1602 }
1603 free_elfcorebuf();
1604
1605 /* clear vmcore device dump list */
1606 vmcore_free_device_dumps();
1607}