Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 1 | /* |
| 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 Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 10 | #include <linux/mm.h> |
David Howells | 2f96b8c | 2013-04-12 00:10:25 +0100 | [diff] [blame] | 11 | #include <linux/kcore.h> |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 12 | #include <linux/user.h> |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 13 | #include <linux/elf.h> |
| 14 | #include <linux/elfcore.h> |
Paul Gortmaker | afeacc8 | 2011-05-26 16:00:52 -0400 | [diff] [blame] | 15 | #include <linux/export.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 16 | #include <linux/slab.h> |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 17 | #include <linux/highmem.h> |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 18 | #include <linux/printk.h> |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 19 | #include <linux/bootmem.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/crash_dump.h> |
| 22 | #include <linux/list.h> |
| 23 | #include <asm/uaccess.h> |
| 24 | #include <asm/io.h> |
David Howells | 2f96b8c | 2013-04-12 00:10:25 +0100 | [diff] [blame] | 25 | #include "internal.h" |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 26 | |
| 27 | /* List representing chunks of contiguous memory areas and their offsets in |
| 28 | * vmcore file. |
| 29 | */ |
| 30 | static LIST_HEAD(vmcore_list); |
| 31 | |
| 32 | /* Stores the pointer to the buffer containing kernel elf core headers. */ |
| 33 | static char *elfcorebuf; |
| 34 | static size_t elfcorebuf_sz; |
| 35 | |
| 36 | /* Total size of vmcore file. */ |
| 37 | static u64 vmcore_size; |
| 38 | |
Alexey Dobriyan | 5aa140c | 2008-10-06 14:36:31 +0400 | [diff] [blame] | 39 | static struct proc_dir_entry *proc_vmcore = NULL; |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 40 | |
Olaf Hering | 997c136 | 2011-05-26 16:25:54 -0700 | [diff] [blame] | 41 | /* |
| 42 | * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error |
| 43 | * The called function has to take care of module refcounting. |
| 44 | */ |
| 45 | static int (*oldmem_pfn_is_ram)(unsigned long pfn); |
| 46 | |
| 47 | int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)) |
| 48 | { |
| 49 | if (oldmem_pfn_is_ram) |
| 50 | return -EBUSY; |
| 51 | oldmem_pfn_is_ram = fn; |
| 52 | return 0; |
| 53 | } |
| 54 | EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram); |
| 55 | |
| 56 | void unregister_oldmem_pfn_is_ram(void) |
| 57 | { |
| 58 | oldmem_pfn_is_ram = NULL; |
| 59 | wmb(); |
| 60 | } |
| 61 | EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram); |
| 62 | |
| 63 | static int pfn_is_ram(unsigned long pfn) |
| 64 | { |
| 65 | int (*fn)(unsigned long pfn); |
| 66 | /* pfn is ram unless fn() checks pagetype */ |
| 67 | int ret = 1; |
| 68 | |
| 69 | /* |
| 70 | * Ask hypervisor if the pfn is really ram. |
| 71 | * A ballooned page contains no data and reading from such a page |
| 72 | * will cause high load in the hypervisor. |
| 73 | */ |
| 74 | fn = oldmem_pfn_is_ram; |
| 75 | if (fn) |
| 76 | ret = fn(pfn); |
| 77 | |
| 78 | return ret; |
| 79 | } |
| 80 | |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 81 | /* Reads a page from the oldmem device from given offset. */ |
| 82 | static ssize_t read_from_oldmem(char *buf, size_t count, |
Vivek Goyal | 9e9e394 | 2006-01-11 12:17:37 -0800 | [diff] [blame] | 83 | u64 *ppos, int userbuf) |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 84 | { |
| 85 | unsigned long pfn, offset; |
| 86 | size_t nr_bytes; |
| 87 | ssize_t read = 0, tmp; |
| 88 | |
| 89 | if (!count) |
| 90 | return 0; |
| 91 | |
| 92 | offset = (unsigned long)(*ppos % PAGE_SIZE); |
| 93 | pfn = (unsigned long)(*ppos / PAGE_SIZE); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 94 | |
| 95 | do { |
| 96 | if (count > (PAGE_SIZE - offset)) |
| 97 | nr_bytes = PAGE_SIZE - offset; |
| 98 | else |
| 99 | nr_bytes = count; |
| 100 | |
Olaf Hering | 997c136 | 2011-05-26 16:25:54 -0700 | [diff] [blame] | 101 | /* If pfn is not ram, return zeros for sparse dump files */ |
| 102 | if (pfn_is_ram(pfn) == 0) |
| 103 | memset(buf, 0, nr_bytes); |
| 104 | else { |
| 105 | tmp = copy_oldmem_page(pfn, buf, nr_bytes, |
| 106 | offset, userbuf); |
| 107 | if (tmp < 0) |
| 108 | return tmp; |
| 109 | } |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 110 | *ppos += nr_bytes; |
| 111 | count -= nr_bytes; |
| 112 | buf += nr_bytes; |
| 113 | read += nr_bytes; |
| 114 | ++pfn; |
| 115 | offset = 0; |
| 116 | } while (count); |
| 117 | |
| 118 | return read; |
| 119 | } |
| 120 | |
| 121 | /* Maps vmcore file offset to respective physical address in memroy. */ |
| 122 | static u64 map_offset_to_paddr(loff_t offset, struct list_head *vc_list, |
| 123 | struct vmcore **m_ptr) |
| 124 | { |
| 125 | struct vmcore *m; |
| 126 | u64 paddr; |
| 127 | |
| 128 | list_for_each_entry(m, vc_list, list) { |
| 129 | u64 start, end; |
| 130 | start = m->offset; |
| 131 | end = m->offset + m->size - 1; |
| 132 | if (offset >= start && offset <= end) { |
| 133 | paddr = m->paddr + offset - start; |
| 134 | *m_ptr = m; |
| 135 | return paddr; |
| 136 | } |
| 137 | } |
| 138 | *m_ptr = NULL; |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | /* Read from the ELF header and then the crash dump. On error, negative value is |
| 143 | * returned otherwise number of bytes read are returned. |
| 144 | */ |
| 145 | static ssize_t read_vmcore(struct file *file, char __user *buffer, |
| 146 | size_t buflen, loff_t *fpos) |
| 147 | { |
| 148 | ssize_t acc = 0, tmp; |
Vivek Goyal | 80e8ff6 | 2006-04-10 22:54:10 -0700 | [diff] [blame] | 149 | size_t tsz; |
| 150 | u64 start, nr_bytes; |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 151 | struct vmcore *curr_m = NULL; |
| 152 | |
| 153 | if (buflen == 0 || *fpos >= vmcore_size) |
| 154 | return 0; |
| 155 | |
| 156 | /* trim buflen to not go beyond EOF */ |
| 157 | if (buflen > vmcore_size - *fpos) |
| 158 | buflen = vmcore_size - *fpos; |
| 159 | |
| 160 | /* Read ELF core header */ |
| 161 | if (*fpos < elfcorebuf_sz) { |
| 162 | tsz = elfcorebuf_sz - *fpos; |
| 163 | if (buflen < tsz) |
| 164 | tsz = buflen; |
| 165 | if (copy_to_user(buffer, elfcorebuf + *fpos, tsz)) |
| 166 | return -EFAULT; |
| 167 | buflen -= tsz; |
| 168 | *fpos += tsz; |
| 169 | buffer += tsz; |
| 170 | acc += tsz; |
| 171 | |
| 172 | /* leave now if filled buffer already */ |
| 173 | if (buflen == 0) |
| 174 | return acc; |
| 175 | } |
| 176 | |
| 177 | start = map_offset_to_paddr(*fpos, &vmcore_list, &curr_m); |
| 178 | if (!curr_m) |
| 179 | return -EINVAL; |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 180 | |
| 181 | while (buflen) { |
Zhang Yanfei | c2c1b08 | 2013-02-27 17:03:17 -0800 | [diff] [blame] | 182 | tsz = min_t(size_t, buflen, PAGE_SIZE - (start & ~PAGE_MASK)); |
| 183 | |
| 184 | /* Calculate left bytes in current memory segment. */ |
| 185 | nr_bytes = (curr_m->size - (start - curr_m->paddr)); |
| 186 | if (tsz > nr_bytes) |
| 187 | tsz = nr_bytes; |
| 188 | |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 189 | tmp = read_from_oldmem(buffer, tsz, &start, 1); |
| 190 | if (tmp < 0) |
| 191 | return tmp; |
| 192 | buflen -= tsz; |
| 193 | *fpos += tsz; |
| 194 | buffer += tsz; |
| 195 | acc += tsz; |
| 196 | if (start >= (curr_m->paddr + curr_m->size)) { |
| 197 | if (curr_m->list.next == &vmcore_list) |
| 198 | return acc; /*EOF*/ |
| 199 | curr_m = list_entry(curr_m->list.next, |
| 200 | struct vmcore, list); |
| 201 | start = curr_m->paddr; |
| 202 | } |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 203 | } |
| 204 | return acc; |
| 205 | } |
| 206 | |
Alexey Dobriyan | 5aa140c | 2008-10-06 14:36:31 +0400 | [diff] [blame] | 207 | static const struct file_operations proc_vmcore_operations = { |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 208 | .read = read_vmcore, |
Arnd Bergmann | c227e69 | 2010-09-22 13:04:54 -0700 | [diff] [blame] | 209 | .llseek = default_llseek, |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 210 | }; |
| 211 | |
| 212 | static struct vmcore* __init get_new_element(void) |
| 213 | { |
Cyrill Gorcunov | 2f6d311 | 2009-06-17 16:26:00 -0700 | [diff] [blame] | 214 | return kzalloc(sizeof(struct vmcore), GFP_KERNEL); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 215 | } |
| 216 | |
| 217 | static u64 __init get_vmcore_size_elf64(char *elfptr) |
| 218 | { |
| 219 | int i; |
| 220 | u64 size; |
| 221 | Elf64_Ehdr *ehdr_ptr; |
| 222 | Elf64_Phdr *phdr_ptr; |
| 223 | |
| 224 | ehdr_ptr = (Elf64_Ehdr *)elfptr; |
| 225 | phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); |
| 226 | size = sizeof(Elf64_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr)); |
| 227 | for (i = 0; i < ehdr_ptr->e_phnum; i++) { |
| 228 | size += phdr_ptr->p_memsz; |
| 229 | phdr_ptr++; |
| 230 | } |
| 231 | return size; |
| 232 | } |
| 233 | |
Vivek Goyal | 72658e9 | 2005-06-25 14:58:22 -0700 | [diff] [blame] | 234 | static u64 __init get_vmcore_size_elf32(char *elfptr) |
| 235 | { |
| 236 | int i; |
| 237 | u64 size; |
| 238 | Elf32_Ehdr *ehdr_ptr; |
| 239 | Elf32_Phdr *phdr_ptr; |
| 240 | |
| 241 | ehdr_ptr = (Elf32_Ehdr *)elfptr; |
| 242 | phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); |
| 243 | size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr)); |
| 244 | for (i = 0; i < ehdr_ptr->e_phnum; i++) { |
| 245 | size += phdr_ptr->p_memsz; |
| 246 | phdr_ptr++; |
| 247 | } |
| 248 | return size; |
| 249 | } |
| 250 | |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 251 | /* Merges all the PT_NOTE headers into one. */ |
| 252 | static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, |
| 253 | struct list_head *vc_list) |
| 254 | { |
| 255 | int i, nr_ptnote=0, rc=0; |
| 256 | char *tmp; |
| 257 | Elf64_Ehdr *ehdr_ptr; |
| 258 | Elf64_Phdr phdr, *phdr_ptr; |
| 259 | Elf64_Nhdr *nhdr_ptr; |
| 260 | u64 phdr_sz = 0, note_off; |
| 261 | |
| 262 | ehdr_ptr = (Elf64_Ehdr *)elfptr; |
| 263 | phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); |
| 264 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
| 265 | int j; |
| 266 | void *notes_section; |
| 267 | struct vmcore *new; |
| 268 | u64 offset, max_sz, sz, real_sz = 0; |
| 269 | if (phdr_ptr->p_type != PT_NOTE) |
| 270 | continue; |
| 271 | nr_ptnote++; |
| 272 | max_sz = phdr_ptr->p_memsz; |
| 273 | offset = phdr_ptr->p_offset; |
| 274 | notes_section = kmalloc(max_sz, GFP_KERNEL); |
| 275 | if (!notes_section) |
| 276 | return -ENOMEM; |
| 277 | rc = read_from_oldmem(notes_section, max_sz, &offset, 0); |
| 278 | if (rc < 0) { |
| 279 | kfree(notes_section); |
| 280 | return rc; |
| 281 | } |
| 282 | nhdr_ptr = notes_section; |
| 283 | for (j = 0; j < max_sz; j += sz) { |
| 284 | if (nhdr_ptr->n_namesz == 0) |
| 285 | break; |
| 286 | sz = sizeof(Elf64_Nhdr) + |
| 287 | ((nhdr_ptr->n_namesz + 3) & ~3) + |
| 288 | ((nhdr_ptr->n_descsz + 3) & ~3); |
| 289 | real_sz += sz; |
| 290 | nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz); |
| 291 | } |
| 292 | |
| 293 | /* Add this contiguous chunk of notes section to vmcore list.*/ |
| 294 | new = get_new_element(); |
| 295 | if (!new) { |
| 296 | kfree(notes_section); |
| 297 | return -ENOMEM; |
| 298 | } |
| 299 | new->paddr = phdr_ptr->p_offset; |
| 300 | new->size = real_sz; |
| 301 | list_add_tail(&new->list, vc_list); |
| 302 | phdr_sz += real_sz; |
| 303 | kfree(notes_section); |
| 304 | } |
| 305 | |
| 306 | /* Prepare merged PT_NOTE program header. */ |
| 307 | phdr.p_type = PT_NOTE; |
| 308 | phdr.p_flags = 0; |
| 309 | note_off = sizeof(Elf64_Ehdr) + |
| 310 | (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); |
| 311 | phdr.p_offset = note_off; |
| 312 | phdr.p_vaddr = phdr.p_paddr = 0; |
| 313 | phdr.p_filesz = phdr.p_memsz = phdr_sz; |
| 314 | phdr.p_align = 0; |
| 315 | |
| 316 | /* Add merged PT_NOTE program header*/ |
| 317 | tmp = elfptr + sizeof(Elf64_Ehdr); |
| 318 | memcpy(tmp, &phdr, sizeof(phdr)); |
| 319 | tmp += sizeof(phdr); |
| 320 | |
| 321 | /* Remove unwanted PT_NOTE program headers. */ |
| 322 | i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); |
| 323 | *elfsz = *elfsz - i; |
| 324 | memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); |
| 325 | |
| 326 | /* Modify e_phnum to reflect merged headers. */ |
| 327 | ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; |
| 328 | |
| 329 | return 0; |
| 330 | } |
| 331 | |
Vivek Goyal | 72658e9 | 2005-06-25 14:58:22 -0700 | [diff] [blame] | 332 | /* Merges all the PT_NOTE headers into one. */ |
| 333 | static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, |
| 334 | struct list_head *vc_list) |
| 335 | { |
| 336 | int i, nr_ptnote=0, rc=0; |
| 337 | char *tmp; |
| 338 | Elf32_Ehdr *ehdr_ptr; |
| 339 | Elf32_Phdr phdr, *phdr_ptr; |
| 340 | Elf32_Nhdr *nhdr_ptr; |
| 341 | u64 phdr_sz = 0, note_off; |
| 342 | |
| 343 | ehdr_ptr = (Elf32_Ehdr *)elfptr; |
| 344 | phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); |
| 345 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
| 346 | int j; |
| 347 | void *notes_section; |
| 348 | struct vmcore *new; |
| 349 | u64 offset, max_sz, sz, real_sz = 0; |
| 350 | if (phdr_ptr->p_type != PT_NOTE) |
| 351 | continue; |
| 352 | nr_ptnote++; |
| 353 | max_sz = phdr_ptr->p_memsz; |
| 354 | offset = phdr_ptr->p_offset; |
| 355 | notes_section = kmalloc(max_sz, GFP_KERNEL); |
| 356 | if (!notes_section) |
| 357 | return -ENOMEM; |
| 358 | rc = read_from_oldmem(notes_section, max_sz, &offset, 0); |
| 359 | if (rc < 0) { |
| 360 | kfree(notes_section); |
| 361 | return rc; |
| 362 | } |
| 363 | nhdr_ptr = notes_section; |
| 364 | for (j = 0; j < max_sz; j += sz) { |
| 365 | if (nhdr_ptr->n_namesz == 0) |
| 366 | break; |
| 367 | sz = sizeof(Elf32_Nhdr) + |
| 368 | ((nhdr_ptr->n_namesz + 3) & ~3) + |
| 369 | ((nhdr_ptr->n_descsz + 3) & ~3); |
| 370 | real_sz += sz; |
| 371 | nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz); |
| 372 | } |
| 373 | |
| 374 | /* Add this contiguous chunk of notes section to vmcore list.*/ |
| 375 | new = get_new_element(); |
| 376 | if (!new) { |
| 377 | kfree(notes_section); |
| 378 | return -ENOMEM; |
| 379 | } |
| 380 | new->paddr = phdr_ptr->p_offset; |
| 381 | new->size = real_sz; |
| 382 | list_add_tail(&new->list, vc_list); |
| 383 | phdr_sz += real_sz; |
| 384 | kfree(notes_section); |
| 385 | } |
| 386 | |
| 387 | /* Prepare merged PT_NOTE program header. */ |
| 388 | phdr.p_type = PT_NOTE; |
| 389 | phdr.p_flags = 0; |
| 390 | note_off = sizeof(Elf32_Ehdr) + |
| 391 | (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); |
| 392 | phdr.p_offset = note_off; |
| 393 | phdr.p_vaddr = phdr.p_paddr = 0; |
| 394 | phdr.p_filesz = phdr.p_memsz = phdr_sz; |
| 395 | phdr.p_align = 0; |
| 396 | |
| 397 | /* Add merged PT_NOTE program header*/ |
| 398 | tmp = elfptr + sizeof(Elf32_Ehdr); |
| 399 | memcpy(tmp, &phdr, sizeof(phdr)); |
| 400 | tmp += sizeof(phdr); |
| 401 | |
| 402 | /* Remove unwanted PT_NOTE program headers. */ |
| 403 | i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); |
| 404 | *elfsz = *elfsz - i; |
| 405 | memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); |
| 406 | |
| 407 | /* Modify e_phnum to reflect merged headers. */ |
| 408 | ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; |
| 409 | |
| 410 | return 0; |
| 411 | } |
| 412 | |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 413 | /* Add memory chunks represented by program headers to vmcore list. Also update |
| 414 | * the new offset fields of exported program headers. */ |
| 415 | static int __init process_ptload_program_headers_elf64(char *elfptr, |
| 416 | size_t elfsz, |
| 417 | struct list_head *vc_list) |
| 418 | { |
| 419 | int i; |
| 420 | Elf64_Ehdr *ehdr_ptr; |
| 421 | Elf64_Phdr *phdr_ptr; |
| 422 | loff_t vmcore_off; |
| 423 | struct vmcore *new; |
| 424 | |
| 425 | ehdr_ptr = (Elf64_Ehdr *)elfptr; |
| 426 | phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ |
| 427 | |
| 428 | /* First program header is PT_NOTE header. */ |
| 429 | vmcore_off = sizeof(Elf64_Ehdr) + |
| 430 | (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr) + |
| 431 | phdr_ptr->p_memsz; /* Note sections */ |
| 432 | |
| 433 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
| 434 | if (phdr_ptr->p_type != PT_LOAD) |
| 435 | continue; |
| 436 | |
| 437 | /* Add this contiguous chunk of memory to vmcore list.*/ |
| 438 | new = get_new_element(); |
| 439 | if (!new) |
| 440 | return -ENOMEM; |
| 441 | new->paddr = phdr_ptr->p_offset; |
| 442 | new->size = phdr_ptr->p_memsz; |
| 443 | list_add_tail(&new->list, vc_list); |
| 444 | |
| 445 | /* Update the program header offset. */ |
| 446 | phdr_ptr->p_offset = vmcore_off; |
| 447 | vmcore_off = vmcore_off + phdr_ptr->p_memsz; |
| 448 | } |
| 449 | return 0; |
| 450 | } |
| 451 | |
Vivek Goyal | 72658e9 | 2005-06-25 14:58:22 -0700 | [diff] [blame] | 452 | static int __init process_ptload_program_headers_elf32(char *elfptr, |
| 453 | size_t elfsz, |
| 454 | struct list_head *vc_list) |
| 455 | { |
| 456 | int i; |
| 457 | Elf32_Ehdr *ehdr_ptr; |
| 458 | Elf32_Phdr *phdr_ptr; |
| 459 | loff_t vmcore_off; |
| 460 | struct vmcore *new; |
| 461 | |
| 462 | ehdr_ptr = (Elf32_Ehdr *)elfptr; |
| 463 | phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ |
| 464 | |
| 465 | /* First program header is PT_NOTE header. */ |
| 466 | vmcore_off = sizeof(Elf32_Ehdr) + |
| 467 | (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) + |
| 468 | phdr_ptr->p_memsz; /* Note sections */ |
| 469 | |
| 470 | for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { |
| 471 | if (phdr_ptr->p_type != PT_LOAD) |
| 472 | continue; |
| 473 | |
| 474 | /* Add this contiguous chunk of memory to vmcore list.*/ |
| 475 | new = get_new_element(); |
| 476 | if (!new) |
| 477 | return -ENOMEM; |
| 478 | new->paddr = phdr_ptr->p_offset; |
| 479 | new->size = phdr_ptr->p_memsz; |
| 480 | list_add_tail(&new->list, vc_list); |
| 481 | |
| 482 | /* Update the program header offset */ |
| 483 | phdr_ptr->p_offset = vmcore_off; |
| 484 | vmcore_off = vmcore_off + phdr_ptr->p_memsz; |
| 485 | } |
| 486 | return 0; |
| 487 | } |
| 488 | |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 489 | /* Sets offset fields of vmcore elements. */ |
| 490 | static void __init set_vmcore_list_offsets_elf64(char *elfptr, |
| 491 | struct list_head *vc_list) |
| 492 | { |
| 493 | loff_t vmcore_off; |
| 494 | Elf64_Ehdr *ehdr_ptr; |
| 495 | struct vmcore *m; |
| 496 | |
| 497 | ehdr_ptr = (Elf64_Ehdr *)elfptr; |
| 498 | |
| 499 | /* Skip Elf header and program headers. */ |
| 500 | vmcore_off = sizeof(Elf64_Ehdr) + |
| 501 | (ehdr_ptr->e_phnum) * sizeof(Elf64_Phdr); |
| 502 | |
| 503 | list_for_each_entry(m, vc_list, list) { |
| 504 | m->offset = vmcore_off; |
| 505 | vmcore_off += m->size; |
| 506 | } |
| 507 | } |
| 508 | |
Vivek Goyal | 72658e9 | 2005-06-25 14:58:22 -0700 | [diff] [blame] | 509 | /* Sets offset fields of vmcore elements. */ |
| 510 | static void __init set_vmcore_list_offsets_elf32(char *elfptr, |
| 511 | struct list_head *vc_list) |
| 512 | { |
| 513 | loff_t vmcore_off; |
| 514 | Elf32_Ehdr *ehdr_ptr; |
| 515 | struct vmcore *m; |
| 516 | |
| 517 | ehdr_ptr = (Elf32_Ehdr *)elfptr; |
| 518 | |
| 519 | /* Skip Elf header and program headers. */ |
| 520 | vmcore_off = sizeof(Elf32_Ehdr) + |
| 521 | (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr); |
| 522 | |
| 523 | list_for_each_entry(m, vc_list, list) { |
| 524 | m->offset = vmcore_off; |
| 525 | vmcore_off += m->size; |
| 526 | } |
| 527 | } |
| 528 | |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 529 | static int __init parse_crash_elf64_headers(void) |
| 530 | { |
| 531 | int rc=0; |
| 532 | Elf64_Ehdr ehdr; |
| 533 | u64 addr; |
| 534 | |
| 535 | addr = elfcorehdr_addr; |
| 536 | |
| 537 | /* Read Elf header */ |
| 538 | rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0); |
| 539 | if (rc < 0) |
| 540 | return rc; |
| 541 | |
| 542 | /* Do some basic Verification. */ |
| 543 | if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || |
| 544 | (ehdr.e_type != ET_CORE) || |
Mika Westerberg | 9833c39 | 2010-11-19 09:29:24 +0100 | [diff] [blame] | 545 | !vmcore_elf64_check_arch(&ehdr) || |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 546 | ehdr.e_ident[EI_CLASS] != ELFCLASS64 || |
| 547 | ehdr.e_ident[EI_VERSION] != EV_CURRENT || |
| 548 | ehdr.e_version != EV_CURRENT || |
| 549 | ehdr.e_ehsize != sizeof(Elf64_Ehdr) || |
| 550 | ehdr.e_phentsize != sizeof(Elf64_Phdr) || |
| 551 | ehdr.e_phnum == 0) { |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 552 | pr_warn("Warning: Core image elf header is not sane\n"); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 553 | return -EINVAL; |
| 554 | } |
| 555 | |
| 556 | /* Read in all elf headers. */ |
| 557 | elfcorebuf_sz = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr); |
| 558 | elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL); |
| 559 | if (!elfcorebuf) |
| 560 | return -ENOMEM; |
| 561 | addr = elfcorehdr_addr; |
| 562 | rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0); |
| 563 | if (rc < 0) { |
| 564 | kfree(elfcorebuf); |
| 565 | return rc; |
| 566 | } |
| 567 | |
| 568 | /* Merge all PT_NOTE headers into one. */ |
| 569 | rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &vmcore_list); |
| 570 | if (rc) { |
| 571 | kfree(elfcorebuf); |
| 572 | return rc; |
| 573 | } |
| 574 | rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz, |
| 575 | &vmcore_list); |
| 576 | if (rc) { |
| 577 | kfree(elfcorebuf); |
| 578 | return rc; |
| 579 | } |
| 580 | set_vmcore_list_offsets_elf64(elfcorebuf, &vmcore_list); |
| 581 | return 0; |
| 582 | } |
| 583 | |
Vivek Goyal | 72658e9 | 2005-06-25 14:58:22 -0700 | [diff] [blame] | 584 | static int __init parse_crash_elf32_headers(void) |
| 585 | { |
| 586 | int rc=0; |
| 587 | Elf32_Ehdr ehdr; |
| 588 | u64 addr; |
| 589 | |
| 590 | addr = elfcorehdr_addr; |
| 591 | |
| 592 | /* Read Elf header */ |
| 593 | rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0); |
| 594 | if (rc < 0) |
| 595 | return rc; |
| 596 | |
| 597 | /* Do some basic Verification. */ |
| 598 | if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || |
| 599 | (ehdr.e_type != ET_CORE) || |
| 600 | !elf_check_arch(&ehdr) || |
| 601 | ehdr.e_ident[EI_CLASS] != ELFCLASS32|| |
| 602 | ehdr.e_ident[EI_VERSION] != EV_CURRENT || |
| 603 | ehdr.e_version != EV_CURRENT || |
| 604 | ehdr.e_ehsize != sizeof(Elf32_Ehdr) || |
| 605 | ehdr.e_phentsize != sizeof(Elf32_Phdr) || |
| 606 | ehdr.e_phnum == 0) { |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 607 | pr_warn("Warning: Core image elf header is not sane\n"); |
Vivek Goyal | 72658e9 | 2005-06-25 14:58:22 -0700 | [diff] [blame] | 608 | return -EINVAL; |
| 609 | } |
| 610 | |
| 611 | /* Read in all elf headers. */ |
| 612 | elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); |
| 613 | elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL); |
| 614 | if (!elfcorebuf) |
| 615 | return -ENOMEM; |
| 616 | addr = elfcorehdr_addr; |
| 617 | rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0); |
| 618 | if (rc < 0) { |
| 619 | kfree(elfcorebuf); |
| 620 | return rc; |
| 621 | } |
| 622 | |
| 623 | /* Merge all PT_NOTE headers into one. */ |
| 624 | rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list); |
| 625 | if (rc) { |
| 626 | kfree(elfcorebuf); |
| 627 | return rc; |
| 628 | } |
| 629 | rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz, |
| 630 | &vmcore_list); |
| 631 | if (rc) { |
| 632 | kfree(elfcorebuf); |
| 633 | return rc; |
| 634 | } |
| 635 | set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list); |
| 636 | return 0; |
| 637 | } |
| 638 | |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 639 | static int __init parse_crash_elf_headers(void) |
| 640 | { |
| 641 | unsigned char e_ident[EI_NIDENT]; |
| 642 | u64 addr; |
| 643 | int rc=0; |
| 644 | |
| 645 | addr = elfcorehdr_addr; |
| 646 | rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0); |
| 647 | if (rc < 0) |
| 648 | return rc; |
| 649 | if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) { |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 650 | pr_warn("Warning: Core image elf header not found\n"); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 651 | return -EINVAL; |
| 652 | } |
| 653 | |
| 654 | if (e_ident[EI_CLASS] == ELFCLASS64) { |
| 655 | rc = parse_crash_elf64_headers(); |
| 656 | if (rc) |
| 657 | return rc; |
| 658 | |
| 659 | /* Determine vmcore size. */ |
| 660 | vmcore_size = get_vmcore_size_elf64(elfcorebuf); |
Vivek Goyal | 72658e9 | 2005-06-25 14:58:22 -0700 | [diff] [blame] | 661 | } else if (e_ident[EI_CLASS] == ELFCLASS32) { |
| 662 | rc = parse_crash_elf32_headers(); |
| 663 | if (rc) |
| 664 | return rc; |
| 665 | |
| 666 | /* Determine vmcore size. */ |
| 667 | vmcore_size = get_vmcore_size_elf32(elfcorebuf); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 668 | } else { |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 669 | pr_warn("Warning: Core image elf header is not sane\n"); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 670 | return -EINVAL; |
| 671 | } |
| 672 | return 0; |
| 673 | } |
| 674 | |
| 675 | /* Init function for vmcore module. */ |
| 676 | static int __init vmcore_init(void) |
| 677 | { |
| 678 | int rc = 0; |
| 679 | |
| 680 | /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/ |
Simon Horman | 85a0ee3 | 2008-10-18 20:28:29 -0700 | [diff] [blame] | 681 | if (!(is_vmcore_usable())) |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 682 | return rc; |
| 683 | rc = parse_crash_elf_headers(); |
| 684 | if (rc) { |
Andrew Morton | 87ebdc0 | 2013-02-27 17:03:16 -0800 | [diff] [blame] | 685 | pr_warn("Kdump: vmcore not initialized\n"); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 686 | return rc; |
| 687 | } |
| 688 | |
Alexey Dobriyan | 5aa140c | 2008-10-06 14:36:31 +0400 | [diff] [blame] | 689 | proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations); |
Vivek Goyal | 666bfdd | 2005-06-25 14:58:21 -0700 | [diff] [blame] | 690 | if (proc_vmcore) |
| 691 | proc_vmcore->size = vmcore_size; |
| 692 | return 0; |
| 693 | } |
| 694 | module_init(vmcore_init) |
Mahesh Salgaonkar | 16257393 | 2012-02-16 01:15:00 +0000 | [diff] [blame] | 695 | |
| 696 | /* Cleanup function for vmcore module. */ |
| 697 | void vmcore_cleanup(void) |
| 698 | { |
| 699 | struct list_head *pos, *next; |
| 700 | |
| 701 | if (proc_vmcore) { |
David Howells | a8ca16e | 2013-04-12 17:27:28 +0100 | [diff] [blame] | 702 | proc_remove(proc_vmcore); |
Mahesh Salgaonkar | 16257393 | 2012-02-16 01:15:00 +0000 | [diff] [blame] | 703 | proc_vmcore = NULL; |
| 704 | } |
| 705 | |
| 706 | /* clear the vmcore list. */ |
| 707 | list_for_each_safe(pos, next, &vmcore_list) { |
| 708 | struct vmcore *m; |
| 709 | |
| 710 | m = list_entry(pos, struct vmcore, list); |
| 711 | list_del(&m->list); |
| 712 | kfree(m); |
| 713 | } |
| 714 | kfree(elfcorebuf); |
| 715 | elfcorebuf = NULL; |
| 716 | } |
| 717 | EXPORT_SYMBOL_GPL(vmcore_cleanup); |