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staging: rtl8723bs: os_dep: change return type of rtw_suspend_ap_wow
[linux/fpc-iii.git] / fs / proc / vmcore.c
blob7bcc92add72c1f1559e48eed956a58ec91ac824e
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/uaccess.h>
29 #include <linux/mem_encrypt.h>
30 #include <asm/pgtable.h>
31 #include <asm/io.h>
32 #include "internal.h"
33
34 /* List representing chunks of contiguous memory areas and their offsets in
35 * vmcore file.
36 */
37 static LIST_HEAD(vmcore_list);
38
39 /* Stores the pointer to the buffer containing kernel elf core headers. */
40 static char *elfcorebuf;
41 static size_t elfcorebuf_sz;
42 static size_t elfcorebuf_sz_orig;
43
44 static char *elfnotes_buf;
45 static size_t elfnotes_sz;
46 /* Size of all notes minus the device dump notes */
47 static size_t elfnotes_orig_sz;
48
49 /* Total size of vmcore file. */
50 static u64 vmcore_size;
51
52 static struct proc_dir_entry *proc_vmcore;
53
54 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
55 /* Device Dump list and mutex to synchronize access to list */
56 static LIST_HEAD(vmcoredd_list);
57 static DEFINE_MUTEX(vmcoredd_mutex);
58
59 static bool vmcoredd_disabled;
60 core_param(novmcoredd, vmcoredd_disabled, bool, 0);
61 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
62
63 /* Device Dump Size */
64 static size_t vmcoredd_orig_sz;
65
66 /*
67 * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
68 * The called function has to take care of module refcounting.
69 */
70 static int (*oldmem_pfn_is_ram)(unsigned long pfn);
71
72 int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
73 {
74 if (oldmem_pfn_is_ram)
75 return -EBUSY;
76 oldmem_pfn_is_ram = fn;
77 return 0;
78 }
79 EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
80
81 void unregister_oldmem_pfn_is_ram(void)
82 {
83 oldmem_pfn_is_ram = NULL;
84 wmb();
85 }
86 EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
87
88 static int pfn_is_ram(unsigned long pfn)
89 {
90 int (*fn)(unsigned long pfn);
91 /* pfn is ram unless fn() checks pagetype */
92 int ret = 1;
93
94 /*
95 * Ask hypervisor if the pfn is really ram.
96 * A ballooned page contains no data and reading from such a page
97 * will cause high load in the hypervisor.
98 */
99 fn = oldmem_pfn_is_ram;
100 if (fn)
101 ret = fn(pfn);
102
103 return ret;
104 }
105
106 /* Reads a page from the oldmem device from given offset. */
107 static ssize_t read_from_oldmem(char *buf, size_t count,
108 u64 *ppos, int userbuf,
109 bool encrypted)
110 {
111 unsigned long pfn, offset;
112 size_t nr_bytes;
113 ssize_t read = 0, tmp;
114
115 if (!count)
116 return 0;
117
118 offset = (unsigned long)(*ppos % PAGE_SIZE);
119 pfn = (unsigned long)(*ppos / PAGE_SIZE);
120
121 do {
122 if (count > (PAGE_SIZE - offset))
123 nr_bytes = PAGE_SIZE - offset;
124 else
125 nr_bytes = count;
126
127 /* If pfn is not ram, return zeros for sparse dump files */
128 if (pfn_is_ram(pfn) == 0)
129 memset(buf, 0, nr_bytes);
130 else {
131 if (encrypted)
132 tmp = copy_oldmem_page_encrypted(pfn, buf,
133 nr_bytes,
134 offset,
135 userbuf);
136 else
137 tmp = copy_oldmem_page(pfn, buf, nr_bytes,
138 offset, userbuf);
139
140 if (tmp < 0)
141 return tmp;
142 }
143 *ppos += nr_bytes;
144 count -= nr_bytes;
145 buf += nr_bytes;
146 read += nr_bytes;
147 ++pfn;
148 offset = 0;
149 } while (count);
150
151 return read;
152 }
153
154 /*
155 * Architectures may override this function to allocate ELF header in 2nd kernel
156 */
157 int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
158 {
159 return 0;
160 }
161
162 /*
163 * Architectures may override this function to free header
164 */
165 void __weak elfcorehdr_free(unsigned long long addr)
166 {}
167
168 /*
169 * Architectures may override this function to read from ELF header
170 */
171 ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
172 {
173 return read_from_oldmem(buf, count, ppos, 0, sev_active());
174 }
175
176 /*
177 * Architectures may override this function to read from notes sections
178 */
179 ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
180 {
181 return read_from_oldmem(buf, count, ppos, 0, mem_encrypt_active());
182 }
183
184 /*
185 * Architectures may override this function to map oldmem
186 */
187 int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
188 unsigned long from, unsigned long pfn,
189 unsigned long size, pgprot_t prot)
190 {
191 prot = pgprot_encrypted(prot);
192 return remap_pfn_range(vma, from, pfn, size, prot);
193 }
194
195 /*
196 * Architectures which support memory encryption override this.
197 */
198 ssize_t __weak
199 copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
200 unsigned long offset, int userbuf)
201 {
202 return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
203 }
204
205 /*
206 * Copy to either kernel or user space
207 */
208 static int copy_to(void *target, void *src, size_t size, int userbuf)
209 {
210 if (userbuf) {
211 if (copy_to_user((char __user *) target, src, size))
212 return -EFAULT;
213 } else {
214 memcpy(target, src, size);
215 }
216 return 0;
217 }
218
219 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
220 static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf)
221 {
222 struct vmcoredd_node *dump;
223 u64 offset = 0;
224 int ret = 0;
225 size_t tsz;
226 char *buf;
227
228 mutex_lock(&vmcoredd_mutex);
229 list_for_each_entry(dump, &vmcoredd_list, list) {
230 if (start < offset + dump->size) {
231 tsz = min(offset + (u64)dump->size - start, (u64)size);
232 buf = dump->buf + start - offset;
233 if (copy_to(dst, buf, tsz, userbuf)) {
234 ret = -EFAULT;
235 goto out_unlock;
236 }
237
238 size -= tsz;
239 start += tsz;
240 dst += tsz;
241
242 /* Leave now if buffer filled already */
243 if (!size)
244 goto out_unlock;
245 }
246 offset += dump->size;
247 }
248
249 out_unlock:
250 mutex_unlock(&vmcoredd_mutex);
251 return ret;
252 }
253
254 #ifdef CONFIG_MMU
255 static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst,
256 u64 start, size_t size)
257 {
258 struct vmcoredd_node *dump;
259 u64 offset = 0;
260 int ret = 0;
261 size_t tsz;
262 char *buf;
263
264 mutex_lock(&vmcoredd_mutex);
265 list_for_each_entry(dump, &vmcoredd_list, list) {
266 if (start < offset + dump->size) {
267 tsz = min(offset + (u64)dump->size - start, (u64)size);
268 buf = dump->buf + start - offset;
269 if (remap_vmalloc_range_partial(vma, dst, buf, tsz)) {
270 ret = -EFAULT;
271 goto out_unlock;
272 }
273
274 size -= tsz;
275 start += tsz;
276 dst += tsz;
277
278 /* Leave now if buffer filled already */
279 if (!size)
280 goto out_unlock;
281 }
282 offset += dump->size;
283 }
284
285 out_unlock:
286 mutex_unlock(&vmcoredd_mutex);
287 return ret;
288 }
289 #endif /* CONFIG_MMU */
290 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
291
292 /* Read from the ELF header and then the crash dump. On error, negative value is
293 * returned otherwise number of bytes read are returned.
294 */
295 static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
296 int userbuf)
297 {
298 ssize_t acc = 0, tmp;
299 size_t tsz;
300 u64 start;
301 struct vmcore *m = NULL;
302
303 if (buflen == 0 || *fpos >= vmcore_size)
304 return 0;
305
306 /* trim buflen to not go beyond EOF */
307 if (buflen > vmcore_size - *fpos)
308 buflen = vmcore_size - *fpos;
309
310 /* Read ELF core header */
311 if (*fpos < elfcorebuf_sz) {
312 tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
313 if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
314 return -EFAULT;
315 buflen -= tsz;
316 *fpos += tsz;
317 buffer += tsz;
318 acc += tsz;
319
320 /* leave now if filled buffer already */
321 if (buflen == 0)
322 return acc;
323 }
324
325 /* Read Elf note segment */
326 if (*fpos < elfcorebuf_sz + elfnotes_sz) {
327 void *kaddr;
328
329 /* We add device dumps before other elf notes because the
330 * other elf notes may not fill the elf notes buffer
331 * completely and we will end up with zero-filled data
332 * between the elf notes and the device dumps. Tools will
333 * then try to decode this zero-filled data as valid notes
334 * and we don't want that. Hence, adding device dumps before
335 * the other elf notes ensure that zero-filled data can be
336 * avoided.
337 */
338 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
339 /* Read device dumps */
340 if (*fpos < elfcorebuf_sz + vmcoredd_orig_sz) {
341 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
342 (size_t)*fpos, buflen);
343 start = *fpos - elfcorebuf_sz;
344 if (vmcoredd_copy_dumps(buffer, start, tsz, userbuf))
345 return -EFAULT;
346
347 buflen -= tsz;
348 *fpos += tsz;
349 buffer += tsz;
350 acc += tsz;
351
352 /* leave now if filled buffer already */
353 if (!buflen)
354 return acc;
355 }
356 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
357
358 /* Read remaining elf notes */
359 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
360 kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz;
361 if (copy_to(buffer, kaddr, tsz, userbuf))
362 return -EFAULT;
363
364 buflen -= tsz;
365 *fpos += tsz;
366 buffer += tsz;
367 acc += tsz;
368
369 /* leave now if filled buffer already */
370 if (buflen == 0)
371 return acc;
372 }
373
374 list_for_each_entry(m, &vmcore_list, list) {
375 if (*fpos < m->offset + m->size) {
376 tsz = (size_t)min_t(unsigned long long,
377 m->offset + m->size - *fpos,
378 buflen);
379 start = m->paddr + *fpos - m->offset;
380 tmp = read_from_oldmem(buffer, tsz, &start,
381 userbuf, mem_encrypt_active());
382 if (tmp < 0)
383 return tmp;
384 buflen -= tsz;
385 *fpos += tsz;
386 buffer += tsz;
387 acc += tsz;
388
389 /* leave now if filled buffer already */
390 if (buflen == 0)
391 return acc;
392 }
393 }
394
395 return acc;
396 }
397
398 static ssize_t read_vmcore(struct file *file, char __user *buffer,
399 size_t buflen, loff_t *fpos)
400 {
401 return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
402 }
403
404 /*
405 * The vmcore fault handler uses the page cache and fills data using the
406 * standard __vmcore_read() function.
407 *
408 * On s390 the fault handler is used for memory regions that can't be mapped
409 * directly with remap_pfn_range().
410 */
411 static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
412 {
413 #ifdef CONFIG_S390
414 struct address_space *mapping = vmf->vma->vm_file->f_mapping;
415 pgoff_t index = vmf->pgoff;
416 struct page *page;
417 loff_t offset;
418 char *buf;
419 int rc;
420
421 page = find_or_create_page(mapping, index, GFP_KERNEL);
422 if (!page)
423 return VM_FAULT_OOM;
424 if (!PageUptodate(page)) {
425 offset = (loff_t) index << PAGE_SHIFT;
426 buf = __va((page_to_pfn(page) << PAGE_SHIFT));
427 rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0);
428 if (rc < 0) {
429 unlock_page(page);
430 put_page(page);
431 return vmf_error(rc);
432 }
433 SetPageUptodate(page);
434 }
435 unlock_page(page);
436 vmf->page = page;
437 return 0;
438 #else
439 return VM_FAULT_SIGBUS;
440 #endif
441 }
442
443 static const struct vm_operations_struct vmcore_mmap_ops = {
444 .fault = mmap_vmcore_fault,
445 };
446
447 /**
448 * vmcore_alloc_buf - allocate buffer in vmalloc memory
449 * @sizez: size of buffer
450 *
451 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
452 * the buffer to user-space by means of remap_vmalloc_range().
453 *
454 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
455 * disabled and there's no need to allow users to mmap the buffer.
456 */
457 static inline char *vmcore_alloc_buf(size_t size)
458 {
459 #ifdef CONFIG_MMU
460 return vmalloc_user(size);
461 #else
462 return vzalloc(size);
463 #endif
464 }
465
466 /*
467 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
468 * essential for mmap_vmcore() in order to map physically
469 * non-contiguous objects (ELF header, ELF note segment and memory
470 * regions in the 1st kernel pointed to by PT_LOAD entries) into
471 * virtually contiguous user-space in ELF layout.
472 */
473 #ifdef CONFIG_MMU
474 /*
475 * remap_oldmem_pfn_checked - do remap_oldmem_pfn_range replacing all pages
476 * reported as not being ram with the zero page.
477 *
478 * @vma: vm_area_struct describing requested mapping
479 * @from: start remapping from
480 * @pfn: page frame number to start remapping to
481 * @size: remapping size
482 * @prot: protection bits
483 *
484 * Returns zero on success, -EAGAIN on failure.
485 */
486 static int remap_oldmem_pfn_checked(struct vm_area_struct *vma,
487 unsigned long from, unsigned long pfn,
488 unsigned long size, pgprot_t prot)
489 {
490 unsigned long map_size;
491 unsigned long pos_start, pos_end, pos;
492 unsigned long zeropage_pfn = my_zero_pfn(0);
493 size_t len = 0;
494
495 pos_start = pfn;
496 pos_end = pfn + (size >> PAGE_SHIFT);
497
498 for (pos = pos_start; pos < pos_end; ++pos) {
499 if (!pfn_is_ram(pos)) {
500 /*
501 * We hit a page which is not ram. Remap the continuous
502 * region between pos_start and pos-1 and replace
503 * the non-ram page at pos with the zero page.
504 */
505 if (pos > pos_start) {
506 /* Remap continuous region */
507 map_size = (pos - pos_start) << PAGE_SHIFT;
508 if (remap_oldmem_pfn_range(vma, from + len,
509 pos_start, map_size,
510 prot))
511 goto fail;
512 len += map_size;
513 }
514 /* Remap the zero page */
515 if (remap_oldmem_pfn_range(vma, from + len,
516 zeropage_pfn,
517 PAGE_SIZE, prot))
518 goto fail;
519 len += PAGE_SIZE;
520 pos_start = pos + 1;
521 }
522 }
523 if (pos > pos_start) {
524 /* Remap the rest */
525 map_size = (pos - pos_start) << PAGE_SHIFT;
526 if (remap_oldmem_pfn_range(vma, from + len, pos_start,
527 map_size, prot))
528 goto fail;
529 }
530 return 0;
531 fail:
532 do_munmap(vma->vm_mm, from, len, NULL);
533 return -EAGAIN;
534 }
535
536 static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma,
537 unsigned long from, unsigned long pfn,
538 unsigned long size, pgprot_t prot)
539 {
540 /*
541 * Check if oldmem_pfn_is_ram was registered to avoid
542 * looping over all pages without a reason.
543 */
544 if (oldmem_pfn_is_ram)
545 return remap_oldmem_pfn_checked(vma, from, pfn, size, prot);
546 else
547 return remap_oldmem_pfn_range(vma, from, pfn, size, prot);
548 }
549
550 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
551 {
552 size_t size = vma->vm_end - vma->vm_start;
553 u64 start, end, len, tsz;
554 struct vmcore *m;
555
556 start = (u64)vma->vm_pgoff << PAGE_SHIFT;
557 end = start + size;
558
559 if (size > vmcore_size || end > vmcore_size)
560 return -EINVAL;
561
562 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
563 return -EPERM;
564
565 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
566 vma->vm_flags |= VM_MIXEDMAP;
567 vma->vm_ops = &vmcore_mmap_ops;
568
569 len = 0;
570
571 if (start < elfcorebuf_sz) {
572 u64 pfn;
573
574 tsz = min(elfcorebuf_sz - (size_t)start, size);
575 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
576 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
577 vma->vm_page_prot))
578 return -EAGAIN;
579 size -= tsz;
580 start += tsz;
581 len += tsz;
582
583 if (size == 0)
584 return 0;
585 }
586
587 if (start < elfcorebuf_sz + elfnotes_sz) {
588 void *kaddr;
589
590 /* We add device dumps before other elf notes because the
591 * other elf notes may not fill the elf notes buffer
592 * completely and we will end up with zero-filled data
593 * between the elf notes and the device dumps. Tools will
594 * then try to decode this zero-filled data as valid notes
595 * and we don't want that. Hence, adding device dumps before
596 * the other elf notes ensure that zero-filled data can be
597 * avoided. This also ensures that the device dumps and
598 * other elf notes can be properly mmaped at page aligned
599 * address.
600 */
601 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
602 /* Read device dumps */
603 if (start < elfcorebuf_sz + vmcoredd_orig_sz) {
604 u64 start_off;
605
606 tsz = min(elfcorebuf_sz + vmcoredd_orig_sz -
607 (size_t)start, size);
608 start_off = start - elfcorebuf_sz;
609 if (vmcoredd_mmap_dumps(vma, vma->vm_start + len,
610 start_off, tsz))
611 goto fail;
612
613 size -= tsz;
614 start += tsz;
615 len += tsz;
616
617 /* leave now if filled buffer already */
618 if (!size)
619 return 0;
620 }
621 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
622
623 /* Read remaining elf notes */
624 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
625 kaddr = elfnotes_buf + start - elfcorebuf_sz - vmcoredd_orig_sz;
626 if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
627 kaddr, tsz))
628 goto fail;
629
630 size -= tsz;
631 start += tsz;
632 len += tsz;
633
634 if (size == 0)
635 return 0;
636 }
637
638 list_for_each_entry(m, &vmcore_list, list) {
639 if (start < m->offset + m->size) {
640 u64 paddr = 0;
641
642 tsz = (size_t)min_t(unsigned long long,
643 m->offset + m->size - start, size);
644 paddr = m->paddr + start - m->offset;
645 if (vmcore_remap_oldmem_pfn(vma, vma->vm_start + len,
646 paddr >> PAGE_SHIFT, tsz,
647 vma->vm_page_prot))
648 goto fail;
649 size -= tsz;
650 start += tsz;
651 len += tsz;
652
653 if (size == 0)
654 return 0;
655 }
656 }
657
658 return 0;
659 fail:
660 do_munmap(vma->vm_mm, vma->vm_start, len, NULL);
661 return -EAGAIN;
662 }
663 #else
664 static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
665 {
666 return -ENOSYS;
667 }
668 #endif
669
670 static const struct file_operations proc_vmcore_operations = {
671 .read = read_vmcore,
672 .llseek = default_llseek,
673 .mmap = mmap_vmcore,
674 };
675
676 static struct vmcore* __init get_new_element(void)
677 {
678 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
679 }
680
681 static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
682 struct list_head *vc_list)
683 {
684 u64 size;
685 struct vmcore *m;
686
687 size = elfsz + elfnotesegsz;
688 list_for_each_entry(m, vc_list, list) {
689 size += m->size;
690 }
691 return size;
692 }
693
694 /**
695 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
696 *
697 * @ehdr_ptr: ELF header
698 *
699 * This function updates p_memsz member of each PT_NOTE entry in the
700 * program header table pointed to by @ehdr_ptr to real size of ELF
701 * note segment.
702 */
703 static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
704 {
705 int i, rc=0;
706 Elf64_Phdr *phdr_ptr;
707 Elf64_Nhdr *nhdr_ptr;
708
709 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
710 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
711 void *notes_section;
712 u64 offset, max_sz, sz, real_sz = 0;
713 if (phdr_ptr->p_type != PT_NOTE)
714 continue;
715 max_sz = phdr_ptr->p_memsz;
716 offset = phdr_ptr->p_offset;
717 notes_section = kmalloc(max_sz, GFP_KERNEL);
718 if (!notes_section)
719 return -ENOMEM;
720 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
721 if (rc < 0) {
722 kfree(notes_section);
723 return rc;
724 }
725 nhdr_ptr = notes_section;
726 while (nhdr_ptr->n_namesz != 0) {
727 sz = sizeof(Elf64_Nhdr) +
728 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
729 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
730 if ((real_sz + sz) > max_sz) {
731 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
732 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
733 break;
734 }
735 real_sz += sz;
736 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
737 }
738 kfree(notes_section);
739 phdr_ptr->p_memsz = real_sz;
740 if (real_sz == 0) {
741 pr_warn("Warning: Zero PT_NOTE entries found\n");
742 }
743 }
744
745 return 0;
746 }
747
748 /**
749 * get_note_number_and_size_elf64 - get the number of PT_NOTE program
750 * headers and sum of real size of their ELF note segment headers and
751 * data.
752 *
753 * @ehdr_ptr: ELF header
754 * @nr_ptnote: buffer for the number of PT_NOTE program headers
755 * @sz_ptnote: buffer for size of unique PT_NOTE program header
756 *
757 * This function is used to merge multiple PT_NOTE program headers
758 * into a unique single one. The resulting unique entry will have
759 * @sz_ptnote in its phdr->p_mem.
760 *
761 * It is assumed that program headers with PT_NOTE type pointed to by
762 * @ehdr_ptr has already been updated by update_note_header_size_elf64
763 * and each of PT_NOTE program headers has actual ELF note segment
764 * size in its p_memsz member.
765 */
766 static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
767 int *nr_ptnote, u64 *sz_ptnote)
768 {
769 int i;
770 Elf64_Phdr *phdr_ptr;
771
772 *nr_ptnote = *sz_ptnote = 0;
773
774 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
775 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
776 if (phdr_ptr->p_type != PT_NOTE)
777 continue;
778 *nr_ptnote += 1;
779 *sz_ptnote += phdr_ptr->p_memsz;
780 }
781
782 return 0;
783 }
784
785 /**
786 * copy_notes_elf64 - copy ELF note segments in a given buffer
787 *
788 * @ehdr_ptr: ELF header
789 * @notes_buf: buffer into which ELF note segments are copied
790 *
791 * This function is used to copy ELF note segment in the 1st kernel
792 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
793 * size of the buffer @notes_buf is equal to or larger than sum of the
794 * real ELF note segment headers and data.
795 *
796 * It is assumed that program headers with PT_NOTE type pointed to by
797 * @ehdr_ptr has already been updated by update_note_header_size_elf64
798 * and each of PT_NOTE program headers has actual ELF note segment
799 * size in its p_memsz member.
800 */
801 static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
802 {
803 int i, rc=0;
804 Elf64_Phdr *phdr_ptr;
805
806 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
807
808 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
809 u64 offset;
810 if (phdr_ptr->p_type != PT_NOTE)
811 continue;
812 offset = phdr_ptr->p_offset;
813 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
814 &offset);
815 if (rc < 0)
816 return rc;
817 notes_buf += phdr_ptr->p_memsz;
818 }
819
820 return 0;
821 }
822
823 /* Merges all the PT_NOTE headers into one. */
824 static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
825 char **notes_buf, size_t *notes_sz)
826 {
827 int i, nr_ptnote=0, rc=0;
828 char *tmp;
829 Elf64_Ehdr *ehdr_ptr;
830 Elf64_Phdr phdr;
831 u64 phdr_sz = 0, note_off;
832
833 ehdr_ptr = (Elf64_Ehdr *)elfptr;
834
835 rc = update_note_header_size_elf64(ehdr_ptr);
836 if (rc < 0)
837 return rc;
838
839 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
840 if (rc < 0)
841 return rc;
842
843 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
844 *notes_buf = vmcore_alloc_buf(*notes_sz);
845 if (!*notes_buf)
846 return -ENOMEM;
847
848 rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
849 if (rc < 0)
850 return rc;
851
852 /* Prepare merged PT_NOTE program header. */
853 phdr.p_type = PT_NOTE;
854 phdr.p_flags = 0;
855 note_off = sizeof(Elf64_Ehdr) +
856 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
857 phdr.p_offset = roundup(note_off, PAGE_SIZE);
858 phdr.p_vaddr = phdr.p_paddr = 0;
859 phdr.p_filesz = phdr.p_memsz = phdr_sz;
860 phdr.p_align = 0;
861
862 /* Add merged PT_NOTE program header*/
863 tmp = elfptr + sizeof(Elf64_Ehdr);
864 memcpy(tmp, &phdr, sizeof(phdr));
865 tmp += sizeof(phdr);
866
867 /* Remove unwanted PT_NOTE program headers. */
868 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
869 *elfsz = *elfsz - i;
870 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
871 memset(elfptr + *elfsz, 0, i);
872 *elfsz = roundup(*elfsz, PAGE_SIZE);
873
874 /* Modify e_phnum to reflect merged headers. */
875 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
876
877 /* Store the size of all notes. We need this to update the note
878 * header when the device dumps will be added.
879 */
880 elfnotes_orig_sz = phdr.p_memsz;
881
882 return 0;
883 }
884
885 /**
886 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
887 *
888 * @ehdr_ptr: ELF header
889 *
890 * This function updates p_memsz member of each PT_NOTE entry in the
891 * program header table pointed to by @ehdr_ptr to real size of ELF
892 * note segment.
893 */
894 static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
895 {
896 int i, rc=0;
897 Elf32_Phdr *phdr_ptr;
898 Elf32_Nhdr *nhdr_ptr;
899
900 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
901 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
902 void *notes_section;
903 u64 offset, max_sz, sz, real_sz = 0;
904 if (phdr_ptr->p_type != PT_NOTE)
905 continue;
906 max_sz = phdr_ptr->p_memsz;
907 offset = phdr_ptr->p_offset;
908 notes_section = kmalloc(max_sz, GFP_KERNEL);
909 if (!notes_section)
910 return -ENOMEM;
911 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
912 if (rc < 0) {
913 kfree(notes_section);
914 return rc;
915 }
916 nhdr_ptr = notes_section;
917 while (nhdr_ptr->n_namesz != 0) {
918 sz = sizeof(Elf32_Nhdr) +
919 (((u64)nhdr_ptr->n_namesz + 3) & ~3) +
920 (((u64)nhdr_ptr->n_descsz + 3) & ~3);
921 if ((real_sz + sz) > max_sz) {
922 pr_warn("Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x%x, n_descsz=0x%x\n",
923 nhdr_ptr->n_namesz, nhdr_ptr->n_descsz);
924 break;
925 }
926 real_sz += sz;
927 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
928 }
929 kfree(notes_section);
930 phdr_ptr->p_memsz = real_sz;
931 if (real_sz == 0) {
932 pr_warn("Warning: Zero PT_NOTE entries found\n");
933 }
934 }
935
936 return 0;
937 }
938
939 /**
940 * get_note_number_and_size_elf32 - get the number of PT_NOTE program
941 * headers and sum of real size of their ELF note segment headers and
942 * data.
943 *
944 * @ehdr_ptr: ELF header
945 * @nr_ptnote: buffer for the number of PT_NOTE program headers
946 * @sz_ptnote: buffer for size of unique PT_NOTE program header
947 *
948 * This function is used to merge multiple PT_NOTE program headers
949 * into a unique single one. The resulting unique entry will have
950 * @sz_ptnote in its phdr->p_mem.
951 *
952 * It is assumed that program headers with PT_NOTE type pointed to by
953 * @ehdr_ptr has already been updated by update_note_header_size_elf32
954 * and each of PT_NOTE program headers has actual ELF note segment
955 * size in its p_memsz member.
956 */
957 static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
958 int *nr_ptnote, u64 *sz_ptnote)
959 {
960 int i;
961 Elf32_Phdr *phdr_ptr;
962
963 *nr_ptnote = *sz_ptnote = 0;
964
965 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
966 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
967 if (phdr_ptr->p_type != PT_NOTE)
968 continue;
969 *nr_ptnote += 1;
970 *sz_ptnote += phdr_ptr->p_memsz;
971 }
972
973 return 0;
974 }
975
976 /**
977 * copy_notes_elf32 - copy ELF note segments in a given buffer
978 *
979 * @ehdr_ptr: ELF header
980 * @notes_buf: buffer into which ELF note segments are copied
981 *
982 * This function is used to copy ELF note segment in the 1st kernel
983 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
984 * size of the buffer @notes_buf is equal to or larger than sum of the
985 * real ELF note segment headers and data.
986 *
987 * It is assumed that program headers with PT_NOTE type pointed to by
988 * @ehdr_ptr has already been updated by update_note_header_size_elf32
989 * and each of PT_NOTE program headers has actual ELF note segment
990 * size in its p_memsz member.
991 */
992 static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
993 {
994 int i, rc=0;
995 Elf32_Phdr *phdr_ptr;
996
997 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
998
999 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1000 u64 offset;
1001 if (phdr_ptr->p_type != PT_NOTE)
1002 continue;
1003 offset = phdr_ptr->p_offset;
1004 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
1005 &offset);
1006 if (rc < 0)
1007 return rc;
1008 notes_buf += phdr_ptr->p_memsz;
1009 }
1010
1011 return 0;
1012 }
1013
1014 /* Merges all the PT_NOTE headers into one. */
1015 static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
1016 char **notes_buf, size_t *notes_sz)
1017 {
1018 int i, nr_ptnote=0, rc=0;
1019 char *tmp;
1020 Elf32_Ehdr *ehdr_ptr;
1021 Elf32_Phdr phdr;
1022 u64 phdr_sz = 0, note_off;
1023
1024 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1025
1026 rc = update_note_header_size_elf32(ehdr_ptr);
1027 if (rc < 0)
1028 return rc;
1029
1030 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
1031 if (rc < 0)
1032 return rc;
1033
1034 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
1035 *notes_buf = vmcore_alloc_buf(*notes_sz);
1036 if (!*notes_buf)
1037 return -ENOMEM;
1038
1039 rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
1040 if (rc < 0)
1041 return rc;
1042
1043 /* Prepare merged PT_NOTE program header. */
1044 phdr.p_type = PT_NOTE;
1045 phdr.p_flags = 0;
1046 note_off = sizeof(Elf32_Ehdr) +
1047 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
1048 phdr.p_offset = roundup(note_off, PAGE_SIZE);
1049 phdr.p_vaddr = phdr.p_paddr = 0;
1050 phdr.p_filesz = phdr.p_memsz = phdr_sz;
1051 phdr.p_align = 0;
1052
1053 /* Add merged PT_NOTE program header*/
1054 tmp = elfptr + sizeof(Elf32_Ehdr);
1055 memcpy(tmp, &phdr, sizeof(phdr));
1056 tmp += sizeof(phdr);
1057
1058 /* Remove unwanted PT_NOTE program headers. */
1059 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
1060 *elfsz = *elfsz - i;
1061 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
1062 memset(elfptr + *elfsz, 0, i);
1063 *elfsz = roundup(*elfsz, PAGE_SIZE);
1064
1065 /* Modify e_phnum to reflect merged headers. */
1066 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
1067
1068 /* Store the size of all notes. We need this to update the note
1069 * header when the device dumps will be added.
1070 */
1071 elfnotes_orig_sz = phdr.p_memsz;
1072
1073 return 0;
1074 }
1075
1076 /* Add memory chunks represented by program headers to vmcore list. Also update
1077 * the new offset fields of exported program headers. */
1078 static int __init process_ptload_program_headers_elf64(char *elfptr,
1079 size_t elfsz,
1080 size_t elfnotes_sz,
1081 struct list_head *vc_list)
1082 {
1083 int i;
1084 Elf64_Ehdr *ehdr_ptr;
1085 Elf64_Phdr *phdr_ptr;
1086 loff_t vmcore_off;
1087 struct vmcore *new;
1088
1089 ehdr_ptr = (Elf64_Ehdr *)elfptr;
1090 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
1091
1092 /* Skip Elf header, program headers and Elf note segment. */
1093 vmcore_off = elfsz + elfnotes_sz;
1094
1095 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1096 u64 paddr, start, end, size;
1097
1098 if (phdr_ptr->p_type != PT_LOAD)
1099 continue;
1100
1101 paddr = phdr_ptr->p_offset;
1102 start = rounddown(paddr, PAGE_SIZE);
1103 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1104 size = end - start;
1105
1106 /* Add this contiguous chunk of memory to vmcore list.*/
1107 new = get_new_element();
1108 if (!new)
1109 return -ENOMEM;
1110 new->paddr = start;
1111 new->size = size;
1112 list_add_tail(&new->list, vc_list);
1113
1114 /* Update the program header offset. */
1115 phdr_ptr->p_offset = vmcore_off + (paddr - start);
1116 vmcore_off = vmcore_off + size;
1117 }
1118 return 0;
1119 }
1120
1121 static int __init process_ptload_program_headers_elf32(char *elfptr,
1122 size_t elfsz,
1123 size_t elfnotes_sz,
1124 struct list_head *vc_list)
1125 {
1126 int i;
1127 Elf32_Ehdr *ehdr_ptr;
1128 Elf32_Phdr *phdr_ptr;
1129 loff_t vmcore_off;
1130 struct vmcore *new;
1131
1132 ehdr_ptr = (Elf32_Ehdr *)elfptr;
1133 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
1134
1135 /* Skip Elf header, program headers and Elf note segment. */
1136 vmcore_off = elfsz + elfnotes_sz;
1137
1138 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
1139 u64 paddr, start, end, size;
1140
1141 if (phdr_ptr->p_type != PT_LOAD)
1142 continue;
1143
1144 paddr = phdr_ptr->p_offset;
1145 start = rounddown(paddr, PAGE_SIZE);
1146 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
1147 size = end - start;
1148
1149 /* Add this contiguous chunk of memory to vmcore list.*/
1150 new = get_new_element();
1151 if (!new)
1152 return -ENOMEM;
1153 new->paddr = start;
1154 new->size = size;
1155 list_add_tail(&new->list, vc_list);
1156
1157 /* Update the program header offset */
1158 phdr_ptr->p_offset = vmcore_off + (paddr - start);
1159 vmcore_off = vmcore_off + size;
1160 }
1161 return 0;
1162 }
1163
1164 /* Sets offset fields of vmcore elements. */
1165 static void set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
1166 struct list_head *vc_list)
1167 {
1168 loff_t vmcore_off;
1169 struct vmcore *m;
1170
1171 /* Skip Elf header, program headers and Elf note segment. */
1172 vmcore_off = elfsz + elfnotes_sz;
1173
1174 list_for_each_entry(m, vc_list, list) {
1175 m->offset = vmcore_off;
1176 vmcore_off += m->size;
1177 }
1178 }
1179
1180 static void free_elfcorebuf(void)
1181 {
1182 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
1183 elfcorebuf = NULL;
1184 vfree(elfnotes_buf);
1185 elfnotes_buf = NULL;
1186 }
1187
1188 static int __init parse_crash_elf64_headers(void)
1189 {
1190 int rc=0;
1191 Elf64_Ehdr ehdr;
1192 u64 addr;
1193
1194 addr = elfcorehdr_addr;
1195
1196 /* Read Elf header */
1197 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
1198 if (rc < 0)
1199 return rc;
1200
1201 /* Do some basic Verification. */
1202 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
1203 (ehdr.e_type != ET_CORE) ||
1204 !vmcore_elf64_check_arch(&ehdr) ||
1205 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
1206 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
1207 ehdr.e_version != EV_CURRENT ||
1208 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
1209 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
1210 ehdr.e_phnum == 0) {
1211 pr_warn("Warning: Core image elf header is not sane\n");
1212 return -EINVAL;
1213 }
1214
1215 /* Read in all elf headers. */
1216 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
1217 ehdr.e_phnum * sizeof(Elf64_Phdr);
1218 elfcorebuf_sz = elfcorebuf_sz_orig;
1219 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1220 get_order(elfcorebuf_sz_orig));
1221 if (!elfcorebuf)
1222 return -ENOMEM;
1223 addr = elfcorehdr_addr;
1224 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
1225 if (rc < 0)
1226 goto fail;
1227
1228 /* Merge all PT_NOTE headers into one. */
1229 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
1230 &elfnotes_buf, &elfnotes_sz);
1231 if (rc)
1232 goto fail;
1233 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
1234 elfnotes_sz, &vmcore_list);
1235 if (rc)
1236 goto fail;
1237 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1238 return 0;
1239 fail:
1240 free_elfcorebuf();
1241 return rc;
1242 }
1243
1244 static int __init parse_crash_elf32_headers(void)
1245 {
1246 int rc=0;
1247 Elf32_Ehdr ehdr;
1248 u64 addr;
1249
1250 addr = elfcorehdr_addr;
1251
1252 /* Read Elf header */
1253 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
1254 if (rc < 0)
1255 return rc;
1256
1257 /* Do some basic Verification. */
1258 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
1259 (ehdr.e_type != ET_CORE) ||
1260 !vmcore_elf32_check_arch(&ehdr) ||
1261 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
1262 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
1263 ehdr.e_version != EV_CURRENT ||
1264 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
1265 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
1266 ehdr.e_phnum == 0) {
1267 pr_warn("Warning: Core image elf header is not sane\n");
1268 return -EINVAL;
1269 }
1270
1271 /* Read in all elf headers. */
1272 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
1273 elfcorebuf_sz = elfcorebuf_sz_orig;
1274 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1275 get_order(elfcorebuf_sz_orig));
1276 if (!elfcorebuf)
1277 return -ENOMEM;
1278 addr = elfcorehdr_addr;
1279 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
1280 if (rc < 0)
1281 goto fail;
1282
1283 /* Merge all PT_NOTE headers into one. */
1284 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
1285 &elfnotes_buf, &elfnotes_sz);
1286 if (rc)
1287 goto fail;
1288 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
1289 elfnotes_sz, &vmcore_list);
1290 if (rc)
1291 goto fail;
1292 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1293 return 0;
1294 fail:
1295 free_elfcorebuf();
1296 return rc;
1297 }
1298
1299 static int __init parse_crash_elf_headers(void)
1300 {
1301 unsigned char e_ident[EI_NIDENT];
1302 u64 addr;
1303 int rc=0;
1304
1305 addr = elfcorehdr_addr;
1306 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
1307 if (rc < 0)
1308 return rc;
1309 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
1310 pr_warn("Warning: Core image elf header not found\n");
1311 return -EINVAL;
1312 }
1313
1314 if (e_ident[EI_CLASS] == ELFCLASS64) {
1315 rc = parse_crash_elf64_headers();
1316 if (rc)
1317 return rc;
1318 } else if (e_ident[EI_CLASS] == ELFCLASS32) {
1319 rc = parse_crash_elf32_headers();
1320 if (rc)
1321 return rc;
1322 } else {
1323 pr_warn("Warning: Core image elf header is not sane\n");
1324 return -EINVAL;
1325 }
1326
1327 /* Determine vmcore size. */
1328 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
1329 &vmcore_list);
1330
1331 return 0;
1332 }
1333
1334 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
1335 /**
1336 * vmcoredd_write_header - Write vmcore device dump header at the
1337 * beginning of the dump's buffer.
1338 * @buf: Output buffer where the note is written
1339 * @data: Dump info
1340 * @size: Size of the dump
1341 *
1342 * Fills beginning of the dump's buffer with vmcore device dump header.
1343 */
1344 static void vmcoredd_write_header(void *buf, struct vmcoredd_data *data,
1345 u32 size)
1346 {
1347 struct vmcoredd_header *vdd_hdr = (struct vmcoredd_header *)buf;
1348
1349 vdd_hdr->n_namesz = sizeof(vdd_hdr->name);
1350 vdd_hdr->n_descsz = size + sizeof(vdd_hdr->dump_name);
1351 vdd_hdr->n_type = NT_VMCOREDD;
1352
1353 strncpy((char *)vdd_hdr->name, VMCOREDD_NOTE_NAME,
1354 sizeof(vdd_hdr->name));
1355 memcpy(vdd_hdr->dump_name, data->dump_name, sizeof(vdd_hdr->dump_name));
1356 }
1357
1358 /**
1359 * vmcoredd_update_program_headers - Update all Elf program headers
1360 * @elfptr: Pointer to elf header
1361 * @elfnotesz: Size of elf notes aligned to page size
1362 * @vmcoreddsz: Size of device dumps to be added to elf note header
1363 *
1364 * Determine type of Elf header (Elf64 or Elf32) and update the elf note size.
1365 * Also update the offsets of all the program headers after the elf note header.
1366 */
1367 static void vmcoredd_update_program_headers(char *elfptr, size_t elfnotesz,
1368 size_t vmcoreddsz)
1369 {
1370 unsigned char *e_ident = (unsigned char *)elfptr;
1371 u64 start, end, size;
1372 loff_t vmcore_off;
1373 u32 i;
1374
1375 vmcore_off = elfcorebuf_sz + elfnotesz;
1376
1377 if (e_ident[EI_CLASS] == ELFCLASS64) {
1378 Elf64_Ehdr *ehdr = (Elf64_Ehdr *)elfptr;
1379 Elf64_Phdr *phdr = (Elf64_Phdr *)(elfptr + sizeof(Elf64_Ehdr));
1380
1381 /* Update all program headers */
1382 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
1383 if (phdr->p_type == PT_NOTE) {
1384 /* Update note size */
1385 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
1386 phdr->p_filesz = phdr->p_memsz;
1387 continue;
1388 }
1389
1390 start = rounddown(phdr->p_offset, PAGE_SIZE);
1391 end = roundup(phdr->p_offset + phdr->p_memsz,
1392 PAGE_SIZE);
1393 size = end - start;
1394 phdr->p_offset = vmcore_off + (phdr->p_offset - start);
1395 vmcore_off += size;
1396 }
1397 } else {
1398 Elf32_Ehdr *ehdr = (Elf32_Ehdr *)elfptr;
1399 Elf32_Phdr *phdr = (Elf32_Phdr *)(elfptr + sizeof(Elf32_Ehdr));
1400
1401 /* Update all program headers */
1402 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
1403 if (phdr->p_type == PT_NOTE) {
1404 /* Update note size */
1405 phdr->p_memsz = elfnotes_orig_sz + vmcoreddsz;
1406 phdr->p_filesz = phdr->p_memsz;
1407 continue;
1408 }
1409
1410 start = rounddown(phdr->p_offset, PAGE_SIZE);
1411 end = roundup(phdr->p_offset + phdr->p_memsz,
1412 PAGE_SIZE);
1413 size = end - start;
1414 phdr->p_offset = vmcore_off + (phdr->p_offset - start);
1415 vmcore_off += size;
1416 }
1417 }
1418 }
1419
1420 /**
1421 * vmcoredd_update_size - Update the total size of the device dumps and update
1422 * Elf header
1423 * @dump_size: Size of the current device dump to be added to total size
1424 *
1425 * Update the total size of all the device dumps and update the Elf program
1426 * headers. Calculate the new offsets for the vmcore list and update the
1427 * total vmcore size.
1428 */
1429 static void vmcoredd_update_size(size_t dump_size)
1430 {
1431 vmcoredd_orig_sz += dump_size;
1432 elfnotes_sz = roundup(elfnotes_orig_sz, PAGE_SIZE) + vmcoredd_orig_sz;
1433 vmcoredd_update_program_headers(elfcorebuf, elfnotes_sz,
1434 vmcoredd_orig_sz);
1435
1436 /* Update vmcore list offsets */
1437 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
1438
1439 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
1440 &vmcore_list);
1441 proc_vmcore->size = vmcore_size;
1442 }
1443
1444 /**
1445 * vmcore_add_device_dump - Add a buffer containing device dump to vmcore
1446 * @data: dump info.
1447 *
1448 * Allocate a buffer and invoke the calling driver's dump collect routine.
1449 * Write Elf note at the beginning of the buffer to indicate vmcore device
1450 * dump and add the dump to global list.
1451 */
1452 int vmcore_add_device_dump(struct vmcoredd_data *data)
1453 {
1454 struct vmcoredd_node *dump;
1455 void *buf = NULL;
1456 size_t data_size;
1457 int ret;
1458
1459 if (vmcoredd_disabled) {
1460 pr_err_once("Device dump is disabled\n");
1461 return -EINVAL;
1462 }
1463
1464 if (!data || !strlen(data->dump_name) ||
1465 !data->vmcoredd_callback || !data->size)
1466 return -EINVAL;
1467
1468 dump = vzalloc(sizeof(*dump));
1469 if (!dump) {
1470 ret = -ENOMEM;
1471 goto out_err;
1472 }
1473
1474 /* Keep size of the buffer page aligned so that it can be mmaped */
1475 data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
1476 PAGE_SIZE);
1477
1478 /* Allocate buffer for driver's to write their dumps */
1479 buf = vmcore_alloc_buf(data_size);
1480 if (!buf) {
1481 ret = -ENOMEM;
1482 goto out_err;
1483 }
1484
1485 vmcoredd_write_header(buf, data, data_size -
1486 sizeof(struct vmcoredd_header));
1487
1488 /* Invoke the driver's dump collection routing */
1489 ret = data->vmcoredd_callback(data, buf +
1490 sizeof(struct vmcoredd_header));
1491 if (ret)
1492 goto out_err;
1493
1494 dump->buf = buf;
1495 dump->size = data_size;
1496
1497 /* Add the dump to driver sysfs list */
1498 mutex_lock(&vmcoredd_mutex);
1499 list_add_tail(&dump->list, &vmcoredd_list);
1500 mutex_unlock(&vmcoredd_mutex);
1501
1502 vmcoredd_update_size(data_size);
1503 return 0;
1504
1505 out_err:
1506 if (buf)
1507 vfree(buf);
1508
1509 if (dump)
1510 vfree(dump);
1511
1512 return ret;
1513 }
1514 EXPORT_SYMBOL(vmcore_add_device_dump);
1515 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1516
1517 /* Free all dumps in vmcore device dump list */
1518 static void vmcore_free_device_dumps(void)
1519 {
1520 #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
1521 mutex_lock(&vmcoredd_mutex);
1522 while (!list_empty(&vmcoredd_list)) {
1523 struct vmcoredd_node *dump;
1524
1525 dump = list_first_entry(&vmcoredd_list, struct vmcoredd_node,
1526 list);
1527 list_del(&dump->list);
1528 vfree(dump->buf);
1529 vfree(dump);
1530 }
1531 mutex_unlock(&vmcoredd_mutex);
1532 #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
1533 }
1534
1535 /* Init function for vmcore module. */
1536 static int __init vmcore_init(void)
1537 {
1538 int rc = 0;
1539
1540 /* Allow architectures to allocate ELF header in 2nd kernel */
1541 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
1542 if (rc)
1543 return rc;
1544 /*
1545 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
1546 * then capture the dump.
1547 */
1548 if (!(is_vmcore_usable()))
1549 return rc;
1550 rc = parse_crash_elf_headers();
1551 if (rc) {
1552 pr_warn("Kdump: vmcore not initialized\n");
1553 return rc;
1554 }
1555 elfcorehdr_free(elfcorehdr_addr);
1556 elfcorehdr_addr = ELFCORE_ADDR_ERR;
1557
1558 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
1559 if (proc_vmcore)
1560 proc_vmcore->size = vmcore_size;
1561 return 0;
1562 }
1563 fs_initcall(vmcore_init);
1564
1565 /* Cleanup function for vmcore module. */
1566 void vmcore_cleanup(void)
1567 {
1568 if (proc_vmcore) {
1569 proc_remove(proc_vmcore);
1570 proc_vmcore = NULL;
1571 }
1572
1573 /* clear the vmcore list. */
1574 while (!list_empty(&vmcore_list)) {
1575 struct vmcore *m;
1576
1577 m = list_first_entry(&vmcore_list, struct vmcore, list);
1578 list_del(&m->list);
1579 kfree(m);
1580 }
1581 free_elfcorebuf();
1582
1583 /* clear vmcore device dump list */
1584 vmcore_free_device_dumps();
1585 }
Linux with added FPC-III support