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Vivek Goyal666bfdd2005-06-25 14:58:21 -07001/*
2 * fs/proc/vmcore.c Interface for accessing the crash
3 * dump from the system's previous life.
4 * Heavily borrowed from fs/proc/kcore.c
5 * Created by: Hariprasad Nellitheertha (hari@in.ibm.com)
6 * Copyright (C) IBM Corporation, 2004. All rights reserved
7 *
8 */
9
Vivek Goyal666bfdd2005-06-25 14:58:21 -070010#include <linux/mm.h>
David Howells2f96b8c2013-04-12 00:10:25 +010011#include <linux/kcore.h>
Vivek Goyal666bfdd2005-06-25 14:58:21 -070012#include <linux/user.h>
Vivek Goyal666bfdd2005-06-25 14:58:21 -070013#include <linux/elf.h>
14#include <linux/elfcore.h>
Paul Gortmakerafeacc82011-05-26 16:00:52 -040015#include <linux/export.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090016#include <linux/slab.h>
Vivek Goyal666bfdd2005-06-25 14:58:21 -070017#include <linux/highmem.h>
Andrew Morton87ebdc02013-02-27 17:03:16 -080018#include <linux/printk.h>
Vivek Goyal666bfdd2005-06-25 14:58:21 -070019#include <linux/bootmem.h>
20#include <linux/init.h>
21#include <linux/crash_dump.h>
22#include <linux/list.h>
HATAYAMA Daisuke83086972013-07-03 15:02:23 -070023#include <linux/vmalloc.h>
Michael Holzheu9cb21812013-09-11 14:24:51 -070024#include <linux/pagemap.h>
Vivek Goyal666bfdd2005-06-25 14:58:21 -070025#include <asm/uaccess.h>
26#include <asm/io.h>
David Howells2f96b8c2013-04-12 00:10:25 +010027#include "internal.h"
Vivek Goyal666bfdd2005-06-25 14:58:21 -070028
29/* List representing chunks of contiguous memory areas and their offsets in
30 * vmcore file.
31 */
32static LIST_HEAD(vmcore_list);
33
34/* Stores the pointer to the buffer containing kernel elf core headers. */
35static char *elfcorebuf;
36static size_t elfcorebuf_sz;
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -070037static size_t elfcorebuf_sz_orig;
Vivek Goyal666bfdd2005-06-25 14:58:21 -070038
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -070039static char *elfnotes_buf;
40static size_t elfnotes_sz;
41
Vivek Goyal666bfdd2005-06-25 14:58:21 -070042/* Total size of vmcore file. */
43static u64 vmcore_size;
44
Alexey Dobriyan5aa140c2008-10-06 14:36:31 +040045static struct proc_dir_entry *proc_vmcore = NULL;
Vivek Goyal666bfdd2005-06-25 14:58:21 -070046
Olaf Hering997c1362011-05-26 16:25:54 -070047/*
48 * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
49 * The called function has to take care of module refcounting.
50 */
51static int (*oldmem_pfn_is_ram)(unsigned long pfn);
52
53int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn))
54{
55 if (oldmem_pfn_is_ram)
56 return -EBUSY;
57 oldmem_pfn_is_ram = fn;
58 return 0;
59}
60EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram);
61
62void unregister_oldmem_pfn_is_ram(void)
63{
64 oldmem_pfn_is_ram = NULL;
65 wmb();
66}
67EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram);
68
69static int pfn_is_ram(unsigned long pfn)
70{
71 int (*fn)(unsigned long pfn);
72 /* pfn is ram unless fn() checks pagetype */
73 int ret = 1;
74
75 /*
76 * Ask hypervisor if the pfn is really ram.
77 * A ballooned page contains no data and reading from such a page
78 * will cause high load in the hypervisor.
79 */
80 fn = oldmem_pfn_is_ram;
81 if (fn)
82 ret = fn(pfn);
83
84 return ret;
85}
86
Vivek Goyal666bfdd2005-06-25 14:58:21 -070087/* Reads a page from the oldmem device from given offset. */
88static ssize_t read_from_oldmem(char *buf, size_t count,
Vivek Goyal9e9e3942006-01-11 12:17:37 -080089 u64 *ppos, int userbuf)
Vivek Goyal666bfdd2005-06-25 14:58:21 -070090{
91 unsigned long pfn, offset;
92 size_t nr_bytes;
93 ssize_t read = 0, tmp;
94
95 if (!count)
96 return 0;
97
98 offset = (unsigned long)(*ppos % PAGE_SIZE);
99 pfn = (unsigned long)(*ppos / PAGE_SIZE);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700100
101 do {
102 if (count > (PAGE_SIZE - offset))
103 nr_bytes = PAGE_SIZE - offset;
104 else
105 nr_bytes = count;
106
Olaf Hering997c1362011-05-26 16:25:54 -0700107 /* If pfn is not ram, return zeros for sparse dump files */
108 if (pfn_is_ram(pfn) == 0)
109 memset(buf, 0, nr_bytes);
110 else {
111 tmp = copy_oldmem_page(pfn, buf, nr_bytes,
112 offset, userbuf);
113 if (tmp < 0)
114 return tmp;
115 }
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700116 *ppos += nr_bytes;
117 count -= nr_bytes;
118 buf += nr_bytes;
119 read += nr_bytes;
120 ++pfn;
121 offset = 0;
122 } while (count);
123
124 return read;
125}
126
Michael Holzheube8a8d02013-09-11 14:24:49 -0700127/*
128 * Architectures may override this function to allocate ELF header in 2nd kernel
129 */
130int __weak elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
131{
132 return 0;
133}
134
135/*
136 * Architectures may override this function to free header
137 */
138void __weak elfcorehdr_free(unsigned long long addr)
139{}
140
141/*
142 * Architectures may override this function to read from ELF header
143 */
144ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos)
145{
146 return read_from_oldmem(buf, count, ppos, 0);
147}
148
149/*
150 * Architectures may override this function to read from notes sections
151 */
152ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
153{
154 return read_from_oldmem(buf, count, ppos, 0);
155}
156
Michael Holzheu9cb21812013-09-11 14:24:51 -0700157/*
158 * Architectures may override this function to map oldmem
159 */
160int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
161 unsigned long from, unsigned long pfn,
162 unsigned long size, pgprot_t prot)
163{
164 return remap_pfn_range(vma, from, pfn, size, prot);
165}
166
167/*
168 * Copy to either kernel or user space
169 */
170static int copy_to(void *target, void *src, size_t size, int userbuf)
171{
172 if (userbuf) {
173 if (copy_to_user((char __user *) target, src, size))
174 return -EFAULT;
175 } else {
176 memcpy(target, src, size);
177 }
178 return 0;
179}
180
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700181/* Read from the ELF header and then the crash dump. On error, negative value is
182 * returned otherwise number of bytes read are returned.
183 */
Michael Holzheu9cb21812013-09-11 14:24:51 -0700184static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
185 int userbuf)
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700186{
187 ssize_t acc = 0, tmp;
Vivek Goyal80e8ff62006-04-10 22:54:10 -0700188 size_t tsz;
HATAYAMA Daisukeb27eb182013-07-03 15:02:13 -0700189 u64 start;
190 struct vmcore *m = NULL;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700191
192 if (buflen == 0 || *fpos >= vmcore_size)
193 return 0;
194
195 /* trim buflen to not go beyond EOF */
196 if (buflen > vmcore_size - *fpos)
197 buflen = vmcore_size - *fpos;
198
199 /* Read ELF core header */
200 if (*fpos < elfcorebuf_sz) {
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700201 tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
Michael Holzheu9cb21812013-09-11 14:24:51 -0700202 if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700203 return -EFAULT;
204 buflen -= tsz;
205 *fpos += tsz;
206 buffer += tsz;
207 acc += tsz;
208
209 /* leave now if filled buffer already */
210 if (buflen == 0)
211 return acc;
212 }
213
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700214 /* Read Elf note segment */
215 if (*fpos < elfcorebuf_sz + elfnotes_sz) {
216 void *kaddr;
217
218 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
219 kaddr = elfnotes_buf + *fpos - elfcorebuf_sz;
Michael Holzheu9cb21812013-09-11 14:24:51 -0700220 if (copy_to(buffer, kaddr, tsz, userbuf))
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700221 return -EFAULT;
222 buflen -= tsz;
223 *fpos += tsz;
224 buffer += tsz;
225 acc += tsz;
226
227 /* leave now if filled buffer already */
228 if (buflen == 0)
229 return acc;
230 }
231
HATAYAMA Daisukeb27eb182013-07-03 15:02:13 -0700232 list_for_each_entry(m, &vmcore_list, list) {
233 if (*fpos < m->offset + m->size) {
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700234 tsz = min_t(size_t, m->offset + m->size - *fpos, buflen);
HATAYAMA Daisukeb27eb182013-07-03 15:02:13 -0700235 start = m->paddr + *fpos - m->offset;
Michael Holzheu9cb21812013-09-11 14:24:51 -0700236 tmp = read_from_oldmem(buffer, tsz, &start, userbuf);
HATAYAMA Daisukeb27eb182013-07-03 15:02:13 -0700237 if (tmp < 0)
238 return tmp;
239 buflen -= tsz;
240 *fpos += tsz;
241 buffer += tsz;
242 acc += tsz;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700243
HATAYAMA Daisukeb27eb182013-07-03 15:02:13 -0700244 /* leave now if filled buffer already */
245 if (buflen == 0)
246 return acc;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700247 }
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700248 }
HATAYAMA Daisukeb27eb182013-07-03 15:02:13 -0700249
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700250 return acc;
251}
252
Michael Holzheu9cb21812013-09-11 14:24:51 -0700253static ssize_t read_vmcore(struct file *file, char __user *buffer,
254 size_t buflen, loff_t *fpos)
255{
256 return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
257}
258
259/*
260 * The vmcore fault handler uses the page cache and fills data using the
261 * standard __vmcore_read() function.
262 *
263 * On s390 the fault handler is used for memory regions that can't be mapped
264 * directly with remap_pfn_range().
265 */
266static int mmap_vmcore_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
267{
268#ifdef CONFIG_S390
269 struct address_space *mapping = vma->vm_file->f_mapping;
270 pgoff_t index = vmf->pgoff;
271 struct page *page;
272 loff_t offset;
273 char *buf;
274 int rc;
275
276 page = find_or_create_page(mapping, index, GFP_KERNEL);
277 if (!page)
278 return VM_FAULT_OOM;
279 if (!PageUptodate(page)) {
280 offset = (loff_t) index << PAGE_CACHE_SHIFT;
281 buf = __va((page_to_pfn(page) << PAGE_SHIFT));
282 rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0);
283 if (rc < 0) {
284 unlock_page(page);
285 page_cache_release(page);
286 return (rc == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
287 }
288 SetPageUptodate(page);
289 }
290 unlock_page(page);
291 vmf->page = page;
292 return 0;
293#else
294 return VM_FAULT_SIGBUS;
295#endif
296}
297
298static const struct vm_operations_struct vmcore_mmap_ops = {
299 .fault = mmap_vmcore_fault,
300};
301
HATAYAMA Daisuke83086972013-07-03 15:02:23 -0700302/**
303 * alloc_elfnotes_buf - allocate buffer for ELF note segment in
304 * vmalloc memory
305 *
306 * @notes_sz: size of buffer
307 *
308 * If CONFIG_MMU is defined, use vmalloc_user() to allow users to mmap
309 * the buffer to user-space by means of remap_vmalloc_range().
310 *
311 * If CONFIG_MMU is not defined, use vzalloc() since mmap_vmcore() is
312 * disabled and there's no need to allow users to mmap the buffer.
313 */
314static inline char *alloc_elfnotes_buf(size_t notes_sz)
315{
316#ifdef CONFIG_MMU
317 return vmalloc_user(notes_sz);
318#else
319 return vzalloc(notes_sz);
320#endif
321}
322
323/*
324 * Disable mmap_vmcore() if CONFIG_MMU is not defined. MMU is
325 * essential for mmap_vmcore() in order to map physically
326 * non-contiguous objects (ELF header, ELF note segment and memory
327 * regions in the 1st kernel pointed to by PT_LOAD entries) into
328 * virtually contiguous user-space in ELF layout.
329 */
Michael Holzheu11e376a2013-09-11 14:24:53 -0700330#ifdef CONFIG_MMU
HATAYAMA Daisuke83086972013-07-03 15:02:23 -0700331static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
332{
333 size_t size = vma->vm_end - vma->vm_start;
334 u64 start, end, len, tsz;
335 struct vmcore *m;
336
337 start = (u64)vma->vm_pgoff << PAGE_SHIFT;
338 end = start + size;
339
340 if (size > vmcore_size || end > vmcore_size)
341 return -EINVAL;
342
343 if (vma->vm_flags & (VM_WRITE | VM_EXEC))
344 return -EPERM;
345
346 vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);
347 vma->vm_flags |= VM_MIXEDMAP;
Michael Holzheu9cb21812013-09-11 14:24:51 -0700348 vma->vm_ops = &vmcore_mmap_ops;
HATAYAMA Daisuke83086972013-07-03 15:02:23 -0700349
350 len = 0;
351
352 if (start < elfcorebuf_sz) {
353 u64 pfn;
354
355 tsz = min(elfcorebuf_sz - (size_t)start, size);
356 pfn = __pa(elfcorebuf + start) >> PAGE_SHIFT;
357 if (remap_pfn_range(vma, vma->vm_start, pfn, tsz,
358 vma->vm_page_prot))
359 return -EAGAIN;
360 size -= tsz;
361 start += tsz;
362 len += tsz;
363
364 if (size == 0)
365 return 0;
366 }
367
368 if (start < elfcorebuf_sz + elfnotes_sz) {
369 void *kaddr;
370
371 tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)start, size);
372 kaddr = elfnotes_buf + start - elfcorebuf_sz;
373 if (remap_vmalloc_range_partial(vma, vma->vm_start + len,
374 kaddr, tsz))
375 goto fail;
376 size -= tsz;
377 start += tsz;
378 len += tsz;
379
380 if (size == 0)
381 return 0;
382 }
383
384 list_for_each_entry(m, &vmcore_list, list) {
385 if (start < m->offset + m->size) {
386 u64 paddr = 0;
387
388 tsz = min_t(size_t, m->offset + m->size - start, size);
389 paddr = m->paddr + start - m->offset;
Michael Holzheu9cb21812013-09-11 14:24:51 -0700390 if (remap_oldmem_pfn_range(vma, vma->vm_start + len,
391 paddr >> PAGE_SHIFT, tsz,
392 vma->vm_page_prot))
HATAYAMA Daisuke83086972013-07-03 15:02:23 -0700393 goto fail;
394 size -= tsz;
395 start += tsz;
396 len += tsz;
397
398 if (size == 0)
399 return 0;
400 }
401 }
402
403 return 0;
404fail:
405 do_munmap(vma->vm_mm, vma->vm_start, len);
406 return -EAGAIN;
407}
408#else
409static int mmap_vmcore(struct file *file, struct vm_area_struct *vma)
410{
411 return -ENOSYS;
412}
413#endif
414
Alexey Dobriyan5aa140c2008-10-06 14:36:31 +0400415static const struct file_operations proc_vmcore_operations = {
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700416 .read = read_vmcore,
Arnd Bergmannc227e692010-09-22 13:04:54 -0700417 .llseek = default_llseek,
HATAYAMA Daisuke83086972013-07-03 15:02:23 -0700418 .mmap = mmap_vmcore,
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700419};
420
421static struct vmcore* __init get_new_element(void)
422{
Cyrill Gorcunov2f6d3112009-06-17 16:26:00 -0700423 return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700424}
425
HATAYAMA Daisuke591ff712013-07-03 15:02:22 -0700426static u64 __init get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
427 struct list_head *vc_list)
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700428{
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700429 u64 size;
HATAYAMA Daisuke591ff712013-07-03 15:02:22 -0700430 struct vmcore *m;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700431
HATAYAMA Daisuke591ff712013-07-03 15:02:22 -0700432 size = elfsz + elfnotesegsz;
433 list_for_each_entry(m, vc_list, list) {
434 size += m->size;
Vivek Goyal72658e92005-06-25 14:58:22 -0700435 }
436 return size;
437}
438
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700439/**
440 * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry
441 *
442 * @ehdr_ptr: ELF header
443 *
444 * This function updates p_memsz member of each PT_NOTE entry in the
445 * program header table pointed to by @ehdr_ptr to real size of ELF
446 * note segment.
447 */
448static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr)
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700449{
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700450 int i, rc=0;
451 Elf64_Phdr *phdr_ptr;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700452 Elf64_Nhdr *nhdr_ptr;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700453
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700454 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700455 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700456 void *notes_section;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700457 u64 offset, max_sz, sz, real_sz = 0;
458 if (phdr_ptr->p_type != PT_NOTE)
459 continue;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700460 max_sz = phdr_ptr->p_memsz;
461 offset = phdr_ptr->p_offset;
462 notes_section = kmalloc(max_sz, GFP_KERNEL);
463 if (!notes_section)
464 return -ENOMEM;
Michael Holzheube8a8d02013-09-11 14:24:49 -0700465 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700466 if (rc < 0) {
467 kfree(notes_section);
468 return rc;
469 }
470 nhdr_ptr = notes_section;
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700471 while (real_sz < max_sz) {
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700472 if (nhdr_ptr->n_namesz == 0)
473 break;
474 sz = sizeof(Elf64_Nhdr) +
475 ((nhdr_ptr->n_namesz + 3) & ~3) +
476 ((nhdr_ptr->n_descsz + 3) & ~3);
477 real_sz += sz;
478 nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz);
479 }
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700480 kfree(notes_section);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700481 phdr_ptr->p_memsz = real_sz;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700482 }
483
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700484 return 0;
485}
486
487/**
488 * get_note_number_and_size_elf64 - get the number of PT_NOTE program
489 * headers and sum of real size of their ELF note segment headers and
490 * data.
491 *
492 * @ehdr_ptr: ELF header
493 * @nr_ptnote: buffer for the number of PT_NOTE program headers
494 * @sz_ptnote: buffer for size of unique PT_NOTE program header
495 *
496 * This function is used to merge multiple PT_NOTE program headers
497 * into a unique single one. The resulting unique entry will have
498 * @sz_ptnote in its phdr->p_mem.
499 *
500 * It is assumed that program headers with PT_NOTE type pointed to by
501 * @ehdr_ptr has already been updated by update_note_header_size_elf64
502 * and each of PT_NOTE program headers has actual ELF note segment
503 * size in its p_memsz member.
504 */
505static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr,
506 int *nr_ptnote, u64 *sz_ptnote)
507{
508 int i;
509 Elf64_Phdr *phdr_ptr;
510
511 *nr_ptnote = *sz_ptnote = 0;
512
513 phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1);
514 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
515 if (phdr_ptr->p_type != PT_NOTE)
516 continue;
517 *nr_ptnote += 1;
518 *sz_ptnote += phdr_ptr->p_memsz;
519 }
520
521 return 0;
522}
523
524/**
525 * copy_notes_elf64 - copy ELF note segments in a given buffer
526 *
527 * @ehdr_ptr: ELF header
528 * @notes_buf: buffer into which ELF note segments are copied
529 *
530 * This function is used to copy ELF note segment in the 1st kernel
531 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
532 * size of the buffer @notes_buf is equal to or larger than sum of the
533 * real ELF note segment headers and data.
534 *
535 * It is assumed that program headers with PT_NOTE type pointed to by
536 * @ehdr_ptr has already been updated by update_note_header_size_elf64
537 * and each of PT_NOTE program headers has actual ELF note segment
538 * size in its p_memsz member.
539 */
540static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf)
541{
542 int i, rc=0;
543 Elf64_Phdr *phdr_ptr;
544
545 phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1);
546
547 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
548 u64 offset;
549 if (phdr_ptr->p_type != PT_NOTE)
550 continue;
551 offset = phdr_ptr->p_offset;
Michael Holzheube8a8d02013-09-11 14:24:49 -0700552 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
553 &offset);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700554 if (rc < 0)
555 return rc;
556 notes_buf += phdr_ptr->p_memsz;
557 }
558
559 return 0;
560}
561
562/* Merges all the PT_NOTE headers into one. */
563static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
564 char **notes_buf, size_t *notes_sz)
565{
566 int i, nr_ptnote=0, rc=0;
567 char *tmp;
568 Elf64_Ehdr *ehdr_ptr;
569 Elf64_Phdr phdr;
570 u64 phdr_sz = 0, note_off;
571
572 ehdr_ptr = (Elf64_Ehdr *)elfptr;
573
574 rc = update_note_header_size_elf64(ehdr_ptr);
575 if (rc < 0)
576 return rc;
577
578 rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz);
579 if (rc < 0)
580 return rc;
581
582 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
HATAYAMA Daisuke83086972013-07-03 15:02:23 -0700583 *notes_buf = alloc_elfnotes_buf(*notes_sz);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700584 if (!*notes_buf)
585 return -ENOMEM;
586
587 rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
588 if (rc < 0)
589 return rc;
590
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700591 /* Prepare merged PT_NOTE program header. */
592 phdr.p_type = PT_NOTE;
593 phdr.p_flags = 0;
594 note_off = sizeof(Elf64_Ehdr) +
595 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700596 phdr.p_offset = roundup(note_off, PAGE_SIZE);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700597 phdr.p_vaddr = phdr.p_paddr = 0;
598 phdr.p_filesz = phdr.p_memsz = phdr_sz;
599 phdr.p_align = 0;
600
601 /* Add merged PT_NOTE program header*/
602 tmp = elfptr + sizeof(Elf64_Ehdr);
603 memcpy(tmp, &phdr, sizeof(phdr));
604 tmp += sizeof(phdr);
605
606 /* Remove unwanted PT_NOTE program headers. */
607 i = (nr_ptnote - 1) * sizeof(Elf64_Phdr);
608 *elfsz = *elfsz - i;
609 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr)));
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700610 memset(elfptr + *elfsz, 0, i);
611 *elfsz = roundup(*elfsz, PAGE_SIZE);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700612
613 /* Modify e_phnum to reflect merged headers. */
614 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
615
616 return 0;
617}
618
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700619/**
620 * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry
621 *
622 * @ehdr_ptr: ELF header
623 *
624 * This function updates p_memsz member of each PT_NOTE entry in the
625 * program header table pointed to by @ehdr_ptr to real size of ELF
626 * note segment.
627 */
628static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr)
Vivek Goyal72658e92005-06-25 14:58:22 -0700629{
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700630 int i, rc=0;
631 Elf32_Phdr *phdr_ptr;
Vivek Goyal72658e92005-06-25 14:58:22 -0700632 Elf32_Nhdr *nhdr_ptr;
Vivek Goyal72658e92005-06-25 14:58:22 -0700633
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700634 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
Vivek Goyal72658e92005-06-25 14:58:22 -0700635 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
Vivek Goyal72658e92005-06-25 14:58:22 -0700636 void *notes_section;
Vivek Goyal72658e92005-06-25 14:58:22 -0700637 u64 offset, max_sz, sz, real_sz = 0;
638 if (phdr_ptr->p_type != PT_NOTE)
639 continue;
Vivek Goyal72658e92005-06-25 14:58:22 -0700640 max_sz = phdr_ptr->p_memsz;
641 offset = phdr_ptr->p_offset;
642 notes_section = kmalloc(max_sz, GFP_KERNEL);
643 if (!notes_section)
644 return -ENOMEM;
Michael Holzheube8a8d02013-09-11 14:24:49 -0700645 rc = elfcorehdr_read_notes(notes_section, max_sz, &offset);
Vivek Goyal72658e92005-06-25 14:58:22 -0700646 if (rc < 0) {
647 kfree(notes_section);
648 return rc;
649 }
650 nhdr_ptr = notes_section;
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700651 while (real_sz < max_sz) {
Vivek Goyal72658e92005-06-25 14:58:22 -0700652 if (nhdr_ptr->n_namesz == 0)
653 break;
654 sz = sizeof(Elf32_Nhdr) +
655 ((nhdr_ptr->n_namesz + 3) & ~3) +
656 ((nhdr_ptr->n_descsz + 3) & ~3);
657 real_sz += sz;
658 nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
659 }
Vivek Goyal72658e92005-06-25 14:58:22 -0700660 kfree(notes_section);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700661 phdr_ptr->p_memsz = real_sz;
Vivek Goyal72658e92005-06-25 14:58:22 -0700662 }
663
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700664 return 0;
665}
666
667/**
668 * get_note_number_and_size_elf32 - get the number of PT_NOTE program
669 * headers and sum of real size of their ELF note segment headers and
670 * data.
671 *
672 * @ehdr_ptr: ELF header
673 * @nr_ptnote: buffer for the number of PT_NOTE program headers
674 * @sz_ptnote: buffer for size of unique PT_NOTE program header
675 *
676 * This function is used to merge multiple PT_NOTE program headers
677 * into a unique single one. The resulting unique entry will have
678 * @sz_ptnote in its phdr->p_mem.
679 *
680 * It is assumed that program headers with PT_NOTE type pointed to by
681 * @ehdr_ptr has already been updated by update_note_header_size_elf32
682 * and each of PT_NOTE program headers has actual ELF note segment
683 * size in its p_memsz member.
684 */
685static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr,
686 int *nr_ptnote, u64 *sz_ptnote)
687{
688 int i;
689 Elf32_Phdr *phdr_ptr;
690
691 *nr_ptnote = *sz_ptnote = 0;
692
693 phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1);
694 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
695 if (phdr_ptr->p_type != PT_NOTE)
696 continue;
697 *nr_ptnote += 1;
698 *sz_ptnote += phdr_ptr->p_memsz;
699 }
700
701 return 0;
702}
703
704/**
705 * copy_notes_elf32 - copy ELF note segments in a given buffer
706 *
707 * @ehdr_ptr: ELF header
708 * @notes_buf: buffer into which ELF note segments are copied
709 *
710 * This function is used to copy ELF note segment in the 1st kernel
711 * into the buffer @notes_buf in the 2nd kernel. It is assumed that
712 * size of the buffer @notes_buf is equal to or larger than sum of the
713 * real ELF note segment headers and data.
714 *
715 * It is assumed that program headers with PT_NOTE type pointed to by
716 * @ehdr_ptr has already been updated by update_note_header_size_elf32
717 * and each of PT_NOTE program headers has actual ELF note segment
718 * size in its p_memsz member.
719 */
720static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf)
721{
722 int i, rc=0;
723 Elf32_Phdr *phdr_ptr;
724
725 phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1);
726
727 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
728 u64 offset;
729 if (phdr_ptr->p_type != PT_NOTE)
730 continue;
731 offset = phdr_ptr->p_offset;
Michael Holzheube8a8d02013-09-11 14:24:49 -0700732 rc = elfcorehdr_read_notes(notes_buf, phdr_ptr->p_memsz,
733 &offset);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700734 if (rc < 0)
735 return rc;
736 notes_buf += phdr_ptr->p_memsz;
737 }
738
739 return 0;
740}
741
742/* Merges all the PT_NOTE headers into one. */
743static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
744 char **notes_buf, size_t *notes_sz)
745{
746 int i, nr_ptnote=0, rc=0;
747 char *tmp;
748 Elf32_Ehdr *ehdr_ptr;
749 Elf32_Phdr phdr;
750 u64 phdr_sz = 0, note_off;
751
752 ehdr_ptr = (Elf32_Ehdr *)elfptr;
753
754 rc = update_note_header_size_elf32(ehdr_ptr);
755 if (rc < 0)
756 return rc;
757
758 rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz);
759 if (rc < 0)
760 return rc;
761
762 *notes_sz = roundup(phdr_sz, PAGE_SIZE);
HATAYAMA Daisuke83086972013-07-03 15:02:23 -0700763 *notes_buf = alloc_elfnotes_buf(*notes_sz);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700764 if (!*notes_buf)
765 return -ENOMEM;
766
767 rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
768 if (rc < 0)
769 return rc;
770
Vivek Goyal72658e92005-06-25 14:58:22 -0700771 /* Prepare merged PT_NOTE program header. */
772 phdr.p_type = PT_NOTE;
773 phdr.p_flags = 0;
774 note_off = sizeof(Elf32_Ehdr) +
775 (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700776 phdr.p_offset = roundup(note_off, PAGE_SIZE);
Vivek Goyal72658e92005-06-25 14:58:22 -0700777 phdr.p_vaddr = phdr.p_paddr = 0;
778 phdr.p_filesz = phdr.p_memsz = phdr_sz;
779 phdr.p_align = 0;
780
781 /* Add merged PT_NOTE program header*/
782 tmp = elfptr + sizeof(Elf32_Ehdr);
783 memcpy(tmp, &phdr, sizeof(phdr));
784 tmp += sizeof(phdr);
785
786 /* Remove unwanted PT_NOTE program headers. */
787 i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
788 *elfsz = *elfsz - i;
789 memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700790 memset(elfptr + *elfsz, 0, i);
791 *elfsz = roundup(*elfsz, PAGE_SIZE);
Vivek Goyal72658e92005-06-25 14:58:22 -0700792
793 /* Modify e_phnum to reflect merged headers. */
794 ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
795
796 return 0;
797}
798
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700799/* Add memory chunks represented by program headers to vmcore list. Also update
800 * the new offset fields of exported program headers. */
801static int __init process_ptload_program_headers_elf64(char *elfptr,
802 size_t elfsz,
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700803 size_t elfnotes_sz,
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700804 struct list_head *vc_list)
805{
806 int i;
807 Elf64_Ehdr *ehdr_ptr;
808 Elf64_Phdr *phdr_ptr;
809 loff_t vmcore_off;
810 struct vmcore *new;
811
812 ehdr_ptr = (Elf64_Ehdr *)elfptr;
813 phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */
814
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700815 /* Skip Elf header, program headers and Elf note segment. */
816 vmcore_off = elfsz + elfnotes_sz;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700817
818 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700819 u64 paddr, start, end, size;
820
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700821 if (phdr_ptr->p_type != PT_LOAD)
822 continue;
823
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700824 paddr = phdr_ptr->p_offset;
825 start = rounddown(paddr, PAGE_SIZE);
826 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
827 size = end - start;
828
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700829 /* Add this contiguous chunk of memory to vmcore list.*/
830 new = get_new_element();
831 if (!new)
832 return -ENOMEM;
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700833 new->paddr = start;
834 new->size = size;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700835 list_add_tail(&new->list, vc_list);
836
837 /* Update the program header offset. */
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700838 phdr_ptr->p_offset = vmcore_off + (paddr - start);
839 vmcore_off = vmcore_off + size;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700840 }
841 return 0;
842}
843
Vivek Goyal72658e92005-06-25 14:58:22 -0700844static int __init process_ptload_program_headers_elf32(char *elfptr,
845 size_t elfsz,
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700846 size_t elfnotes_sz,
Vivek Goyal72658e92005-06-25 14:58:22 -0700847 struct list_head *vc_list)
848{
849 int i;
850 Elf32_Ehdr *ehdr_ptr;
851 Elf32_Phdr *phdr_ptr;
852 loff_t vmcore_off;
853 struct vmcore *new;
854
855 ehdr_ptr = (Elf32_Ehdr *)elfptr;
856 phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
857
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700858 /* Skip Elf header, program headers and Elf note segment. */
859 vmcore_off = elfsz + elfnotes_sz;
Vivek Goyal72658e92005-06-25 14:58:22 -0700860
861 for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700862 u64 paddr, start, end, size;
863
Vivek Goyal72658e92005-06-25 14:58:22 -0700864 if (phdr_ptr->p_type != PT_LOAD)
865 continue;
866
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700867 paddr = phdr_ptr->p_offset;
868 start = rounddown(paddr, PAGE_SIZE);
869 end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
870 size = end - start;
871
Vivek Goyal72658e92005-06-25 14:58:22 -0700872 /* Add this contiguous chunk of memory to vmcore list.*/
873 new = get_new_element();
874 if (!new)
875 return -ENOMEM;
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700876 new->paddr = start;
877 new->size = size;
Vivek Goyal72658e92005-06-25 14:58:22 -0700878 list_add_tail(&new->list, vc_list);
879
880 /* Update the program header offset */
HATAYAMA Daisuke7f614cd2013-07-03 15:02:15 -0700881 phdr_ptr->p_offset = vmcore_off + (paddr - start);
882 vmcore_off = vmcore_off + size;
Vivek Goyal72658e92005-06-25 14:58:22 -0700883 }
884 return 0;
885}
886
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700887/* Sets offset fields of vmcore elements. */
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700888static void __init set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz,
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700889 struct list_head *vc_list)
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700890{
891 loff_t vmcore_off;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700892 struct vmcore *m;
893
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700894 /* Skip Elf header, program headers and Elf note segment. */
895 vmcore_off = elfsz + elfnotes_sz;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700896
897 list_for_each_entry(m, vc_list, list) {
898 m->offset = vmcore_off;
899 vmcore_off += m->size;
900 }
901}
902
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700903static void free_elfcorebuf(void)
Vivek Goyal72658e92005-06-25 14:58:22 -0700904{
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700905 free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig));
906 elfcorebuf = NULL;
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700907 vfree(elfnotes_buf);
908 elfnotes_buf = NULL;
Vivek Goyal72658e92005-06-25 14:58:22 -0700909}
910
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700911static int __init parse_crash_elf64_headers(void)
912{
913 int rc=0;
914 Elf64_Ehdr ehdr;
915 u64 addr;
916
917 addr = elfcorehdr_addr;
918
919 /* Read Elf header */
Michael Holzheube8a8d02013-09-11 14:24:49 -0700920 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700921 if (rc < 0)
922 return rc;
923
924 /* Do some basic Verification. */
925 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
926 (ehdr.e_type != ET_CORE) ||
Mika Westerberg9833c392010-11-19 09:29:24 +0100927 !vmcore_elf64_check_arch(&ehdr) ||
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700928 ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
929 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
930 ehdr.e_version != EV_CURRENT ||
931 ehdr.e_ehsize != sizeof(Elf64_Ehdr) ||
932 ehdr.e_phentsize != sizeof(Elf64_Phdr) ||
933 ehdr.e_phnum == 0) {
Andrew Morton87ebdc02013-02-27 17:03:16 -0800934 pr_warn("Warning: Core image elf header is not sane\n");
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700935 return -EINVAL;
936 }
937
938 /* Read in all elf headers. */
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700939 elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) +
940 ehdr.e_phnum * sizeof(Elf64_Phdr);
941 elfcorebuf_sz = elfcorebuf_sz_orig;
942 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
943 get_order(elfcorebuf_sz_orig));
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700944 if (!elfcorebuf)
945 return -ENOMEM;
946 addr = elfcorehdr_addr;
Michael Holzheube8a8d02013-09-11 14:24:49 -0700947 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700948 if (rc < 0)
949 goto fail;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700950
951 /* Merge all PT_NOTE headers into one. */
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700952 rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz,
953 &elfnotes_buf, &elfnotes_sz);
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700954 if (rc)
955 goto fail;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700956 rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz,
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700957 elfnotes_sz, &vmcore_list);
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700958 if (rc)
959 goto fail;
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -0700960 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700961 return 0;
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700962fail:
963 free_elfcorebuf();
964 return rc;
Vivek Goyal666bfdd2005-06-25 14:58:21 -0700965}
966
Vivek Goyal72658e92005-06-25 14:58:22 -0700967static int __init parse_crash_elf32_headers(void)
968{
969 int rc=0;
970 Elf32_Ehdr ehdr;
971 u64 addr;
972
973 addr = elfcorehdr_addr;
974
975 /* Read Elf header */
Michael Holzheube8a8d02013-09-11 14:24:49 -0700976 rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
Vivek Goyal72658e92005-06-25 14:58:22 -0700977 if (rc < 0)
978 return rc;
979
980 /* Do some basic Verification. */
981 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
982 (ehdr.e_type != ET_CORE) ||
983 !elf_check_arch(&ehdr) ||
984 ehdr.e_ident[EI_CLASS] != ELFCLASS32||
985 ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
986 ehdr.e_version != EV_CURRENT ||
987 ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
988 ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
989 ehdr.e_phnum == 0) {
Andrew Morton87ebdc02013-02-27 17:03:16 -0800990 pr_warn("Warning: Core image elf header is not sane\n");
Vivek Goyal72658e92005-06-25 14:58:22 -0700991 return -EINVAL;
992 }
993
994 /* Read in all elf headers. */
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -0700995 elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
996 elfcorebuf_sz = elfcorebuf_sz_orig;
997 elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
998 get_order(elfcorebuf_sz_orig));
Vivek Goyal72658e92005-06-25 14:58:22 -0700999 if (!elfcorebuf)
1000 return -ENOMEM;
1001 addr = elfcorehdr_addr;
Michael Holzheube8a8d02013-09-11 14:24:49 -07001002 rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -07001003 if (rc < 0)
1004 goto fail;
Vivek Goyal72658e92005-06-25 14:58:22 -07001005
1006 /* Merge all PT_NOTE headers into one. */
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -07001007 rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz,
1008 &elfnotes_buf, &elfnotes_sz);
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -07001009 if (rc)
1010 goto fail;
Vivek Goyal72658e92005-06-25 14:58:22 -07001011 rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -07001012 elfnotes_sz, &vmcore_list);
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -07001013 if (rc)
1014 goto fail;
HATAYAMA Daisuke087350c2013-07-03 15:02:19 -07001015 set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list);
Vivek Goyal72658e92005-06-25 14:58:22 -07001016 return 0;
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -07001017fail:
1018 free_elfcorebuf();
1019 return rc;
Vivek Goyal72658e92005-06-25 14:58:22 -07001020}
1021
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001022static int __init parse_crash_elf_headers(void)
1023{
1024 unsigned char e_ident[EI_NIDENT];
1025 u64 addr;
1026 int rc=0;
1027
1028 addr = elfcorehdr_addr;
Michael Holzheube8a8d02013-09-11 14:24:49 -07001029 rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001030 if (rc < 0)
1031 return rc;
1032 if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
Andrew Morton87ebdc02013-02-27 17:03:16 -08001033 pr_warn("Warning: Core image elf header not found\n");
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001034 return -EINVAL;
1035 }
1036
1037 if (e_ident[EI_CLASS] == ELFCLASS64) {
1038 rc = parse_crash_elf64_headers();
1039 if (rc)
1040 return rc;
Vivek Goyal72658e92005-06-25 14:58:22 -07001041 } else if (e_ident[EI_CLASS] == ELFCLASS32) {
1042 rc = parse_crash_elf32_headers();
1043 if (rc)
1044 return rc;
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001045 } else {
Andrew Morton87ebdc02013-02-27 17:03:16 -08001046 pr_warn("Warning: Core image elf header is not sane\n");
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001047 return -EINVAL;
1048 }
HATAYAMA Daisuke591ff712013-07-03 15:02:22 -07001049
1050 /* Determine vmcore size. */
1051 vmcore_size = get_vmcore_size(elfcorebuf_sz, elfnotes_sz,
1052 &vmcore_list);
1053
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001054 return 0;
1055}
1056
1057/* Init function for vmcore module. */
1058static int __init vmcore_init(void)
1059{
1060 int rc = 0;
1061
Michael Holzheube8a8d02013-09-11 14:24:49 -07001062 /* Allow architectures to allocate ELF header in 2nd kernel */
1063 rc = elfcorehdr_alloc(&elfcorehdr_addr, &elfcorehdr_size);
1064 if (rc)
1065 return rc;
1066 /*
1067 * If elfcorehdr= has been passed in cmdline or created in 2nd kernel,
1068 * then capture the dump.
1069 */
Simon Horman85a0ee32008-10-18 20:28:29 -07001070 if (!(is_vmcore_usable()))
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001071 return rc;
1072 rc = parse_crash_elf_headers();
1073 if (rc) {
Andrew Morton87ebdc02013-02-27 17:03:16 -08001074 pr_warn("Kdump: vmcore not initialized\n");
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001075 return rc;
1076 }
Michael Holzheube8a8d02013-09-11 14:24:49 -07001077 elfcorehdr_free(elfcorehdr_addr);
1078 elfcorehdr_addr = ELFCORE_ADDR_ERR;
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001079
Alexey Dobriyan5aa140c2008-10-06 14:36:31 +04001080 proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations);
Vivek Goyal666bfdd2005-06-25 14:58:21 -07001081 if (proc_vmcore)
1082 proc_vmcore->size = vmcore_size;
1083 return 0;
1084}
Paul Gortmakerabaf3782014-01-23 15:55:45 -08001085fs_initcall(vmcore_init);
Mahesh Salgaonkar162573932012-02-16 01:15:00 +00001086
1087/* Cleanup function for vmcore module. */
1088void vmcore_cleanup(void)
1089{
1090 struct list_head *pos, *next;
1091
1092 if (proc_vmcore) {
David Howellsa8ca16e2013-04-12 17:27:28 +01001093 proc_remove(proc_vmcore);
Mahesh Salgaonkar162573932012-02-16 01:15:00 +00001094 proc_vmcore = NULL;
1095 }
1096
1097 /* clear the vmcore list. */
1098 list_for_each_safe(pos, next, &vmcore_list) {
1099 struct vmcore *m;
1100
1101 m = list_entry(pos, struct vmcore, list);
1102 list_del(&m->list);
1103 kfree(m);
1104 }
HATAYAMA Daisukef2bdacd2013-07-03 15:02:14 -07001105 free_elfcorebuf();
Mahesh Salgaonkar162573932012-02-16 01:15:00 +00001106}
1107EXPORT_SYMBOL_GPL(vmcore_cleanup);