1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * S390 kdump implementation 4 * 5 * Copyright IBM Corp. 2011 6 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com> 7 */ 8 9 #include <linux/crash_dump.h> 10 #include <asm/lowcore.h> 11 #include <linux/kernel.h> 12 #include <linux/init.h> 13 #include <linux/mm.h> 14 #include <linux/gfp.h> 15 #include <linux/slab.h> 16 #include <linux/memblock.h> 17 #include <linux/elf.h> 18 #include <asm/asm-offsets.h> 19 #include <asm/os_info.h> 20 #include <asm/elf.h> 21 #include <asm/ipl.h> 22 #include <asm/sclp.h> 23 24 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y))) 25 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y))) 26 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y)))) 27 28 static struct memblock_region oldmem_region; 29 30 static struct memblock_type oldmem_type = { 31 .cnt = 1, 32 .max = 1, 33 .total_size = 0, 34 .regions = &oldmem_region, 35 .name = "oldmem", 36 }; 37 38 struct save_area { 39 struct list_head list; 40 u64 psw[2]; 41 u64 ctrs[16]; 42 u64 gprs[16]; 43 u32 acrs[16]; 44 u64 fprs[16]; 45 u32 fpc; 46 u32 prefix; 47 u64 todpreg; 48 u64 timer; 49 u64 todcmp; 50 u64 vxrs_low[16]; 51 __vector128 vxrs_high[16]; 52 }; 53 54 static LIST_HEAD(dump_save_areas); 55 56 /* 57 * Allocate a save area 58 */ 59 struct save_area * __init save_area_alloc(bool is_boot_cpu) 60 { 61 struct save_area *sa; 62 63 sa = (void *) memblock_phys_alloc(sizeof(*sa), 8); 64 if (is_boot_cpu) 65 list_add(&sa->list, &dump_save_areas); 66 else 67 list_add_tail(&sa->list, &dump_save_areas); 68 return sa; 69 } 70 71 /* 72 * Return the address of the save area for the boot CPU 73 */ 74 struct save_area * __init save_area_boot_cpu(void) 75 { 76 return list_first_entry_or_null(&dump_save_areas, struct save_area, list); 77 } 78 79 /* 80 * Copy CPU registers into the save area 81 */ 82 void __init save_area_add_regs(struct save_area *sa, void *regs) 83 { 84 struct lowcore *lc; 85 86 lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA); 87 memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw)); 88 memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs)); 89 memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs)); 90 memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs)); 91 memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs)); 92 memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc)); 93 memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix)); 94 memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg)); 95 memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer)); 96 memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp)); 97 } 98 99 /* 100 * Copy vector registers into the save area 101 */ 102 void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs) 103 { 104 int i; 105 106 /* Copy lower halves of vector registers 0-15 */ 107 for (i = 0; i < 16; i++) 108 memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8); 109 /* Copy vector registers 16-31 */ 110 memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128)); 111 } 112 113 /* 114 * Return physical address for virtual address 115 */ 116 static inline void *load_real_addr(void *addr) 117 { 118 unsigned long real_addr; 119 120 asm volatile( 121 " lra %0,0(%1)\n" 122 " jz 0f\n" 123 " la %0,0\n" 124 "0:" 125 : "=a" (real_addr) : "a" (addr) : "cc"); 126 return (void *)real_addr; 127 } 128 129 /* 130 * Copy memory of the old, dumped system to a kernel space virtual address 131 */ 132 int copy_oldmem_kernel(void *dst, void *src, size_t count) 133 { 134 unsigned long from, len; 135 void *ra; 136 int rc; 137 138 while (count) { 139 from = __pa(src); 140 if (!OLDMEM_BASE && from < sclp.hsa_size) { 141 /* Copy from zfcpdump HSA area */ 142 len = min(count, sclp.hsa_size - from); 143 rc = memcpy_hsa_kernel(dst, from, len); 144 if (rc) 145 return rc; 146 } else { 147 /* Check for swapped kdump oldmem areas */ 148 if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) { 149 from -= OLDMEM_BASE; 150 len = min(count, OLDMEM_SIZE - from); 151 } else if (OLDMEM_BASE && from < OLDMEM_SIZE) { 152 len = min(count, OLDMEM_SIZE - from); 153 from += OLDMEM_BASE; 154 } else { 155 len = count; 156 } 157 if (is_vmalloc_or_module_addr(dst)) { 158 ra = load_real_addr(dst); 159 len = min(PAGE_SIZE - offset_in_page(ra), len); 160 } else { 161 ra = dst; 162 } 163 if (memcpy_real(ra, (void *) from, len)) 164 return -EFAULT; 165 } 166 dst += len; 167 src += len; 168 count -= len; 169 } 170 return 0; 171 } 172 173 /* 174 * Copy memory of the old, dumped system to a user space virtual address 175 */ 176 static int copy_oldmem_user(void __user *dst, void *src, size_t count) 177 { 178 unsigned long from, len; 179 int rc; 180 181 while (count) { 182 from = __pa(src); 183 if (!OLDMEM_BASE && from < sclp.hsa_size) { 184 /* Copy from zfcpdump HSA area */ 185 len = min(count, sclp.hsa_size - from); 186 rc = memcpy_hsa_user(dst, from, len); 187 if (rc) 188 return rc; 189 } else { 190 /* Check for swapped kdump oldmem areas */ 191 if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) { 192 from -= OLDMEM_BASE; 193 len = min(count, OLDMEM_SIZE - from); 194 } else if (OLDMEM_BASE && from < OLDMEM_SIZE) { 195 len = min(count, OLDMEM_SIZE - from); 196 from += OLDMEM_BASE; 197 } else { 198 len = count; 199 } 200 rc = copy_to_user_real(dst, (void *) from, count); 201 if (rc) 202 return rc; 203 } 204 dst += len; 205 src += len; 206 count -= len; 207 } 208 return 0; 209 } 210 211 /* 212 * Copy one page from "oldmem" 213 */ 214 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize, 215 unsigned long offset, int userbuf) 216 { 217 void *src; 218 int rc; 219 220 if (!csize) 221 return 0; 222 src = (void *) (pfn << PAGE_SHIFT) + offset; 223 if (userbuf) 224 rc = copy_oldmem_user((void __force __user *) buf, src, csize); 225 else 226 rc = copy_oldmem_kernel((void *) buf, src, csize); 227 return rc; 228 } 229 230 /* 231 * Remap "oldmem" for kdump 232 * 233 * For the kdump reserved memory this functions performs a swap operation: 234 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] 235 */ 236 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma, 237 unsigned long from, unsigned long pfn, 238 unsigned long size, pgprot_t prot) 239 { 240 unsigned long size_old; 241 int rc; 242 243 if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) { 244 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT)); 245 rc = remap_pfn_range(vma, from, 246 pfn + (OLDMEM_BASE >> PAGE_SHIFT), 247 size_old, prot); 248 if (rc || size == size_old) 249 return rc; 250 size -= size_old; 251 from += size_old; 252 pfn += size_old >> PAGE_SHIFT; 253 } 254 return remap_pfn_range(vma, from, pfn, size, prot); 255 } 256 257 /* 258 * Remap "oldmem" for zfcpdump 259 * 260 * We only map available memory above HSA size. Memory below HSA size 261 * is read on demand using the copy_oldmem_page() function. 262 */ 263 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma, 264 unsigned long from, 265 unsigned long pfn, 266 unsigned long size, pgprot_t prot) 267 { 268 unsigned long hsa_end = sclp.hsa_size; 269 unsigned long size_hsa; 270 271 if (pfn < hsa_end >> PAGE_SHIFT) { 272 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT)); 273 if (size == size_hsa) 274 return 0; 275 size -= size_hsa; 276 from += size_hsa; 277 pfn += size_hsa >> PAGE_SHIFT; 278 } 279 return remap_pfn_range(vma, from, pfn, size, prot); 280 } 281 282 /* 283 * Remap "oldmem" for kdump or zfcpdump 284 */ 285 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from, 286 unsigned long pfn, unsigned long size, pgprot_t prot) 287 { 288 if (OLDMEM_BASE) 289 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot); 290 else 291 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size, 292 prot); 293 } 294 295 static const char *nt_name(Elf64_Word type) 296 { 297 const char *name = "LINUX"; 298 299 if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG) 300 name = KEXEC_CORE_NOTE_NAME; 301 return name; 302 } 303 304 /* 305 * Initialize ELF note 306 */ 307 static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len, 308 const char *name) 309 { 310 Elf64_Nhdr *note; 311 u64 len; 312 313 note = (Elf64_Nhdr *)buf; 314 note->n_namesz = strlen(name) + 1; 315 note->n_descsz = d_len; 316 note->n_type = type; 317 len = sizeof(Elf64_Nhdr); 318 319 memcpy(buf + len, name, note->n_namesz); 320 len = roundup(len + note->n_namesz, 4); 321 322 memcpy(buf + len, desc, note->n_descsz); 323 len = roundup(len + note->n_descsz, 4); 324 325 return PTR_ADD(buf, len); 326 } 327 328 static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len) 329 { 330 return nt_init_name(buf, type, desc, d_len, nt_name(type)); 331 } 332 333 /* 334 * Calculate the size of ELF note 335 */ 336 static size_t nt_size_name(int d_len, const char *name) 337 { 338 size_t size; 339 340 size = sizeof(Elf64_Nhdr); 341 size += roundup(strlen(name) + 1, 4); 342 size += roundup(d_len, 4); 343 344 return size; 345 } 346 347 static inline size_t nt_size(Elf64_Word type, int d_len) 348 { 349 return nt_size_name(d_len, nt_name(type)); 350 } 351 352 /* 353 * Fill ELF notes for one CPU with save area registers 354 */ 355 static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa) 356 { 357 struct elf_prstatus nt_prstatus; 358 elf_fpregset_t nt_fpregset; 359 360 /* Prepare prstatus note */ 361 memset(&nt_prstatus, 0, sizeof(nt_prstatus)); 362 memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs)); 363 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw)); 364 memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs)); 365 nt_prstatus.pr_pid = cpu; 366 /* Prepare fpregset (floating point) note */ 367 memset(&nt_fpregset, 0, sizeof(nt_fpregset)); 368 memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc)); 369 memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs)); 370 /* Create ELF notes for the CPU */ 371 ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus)); 372 ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset)); 373 ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer)); 374 ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp)); 375 ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg)); 376 ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs)); 377 ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix)); 378 if (MACHINE_HAS_VX) { 379 ptr = nt_init(ptr, NT_S390_VXRS_HIGH, 380 &sa->vxrs_high, sizeof(sa->vxrs_high)); 381 ptr = nt_init(ptr, NT_S390_VXRS_LOW, 382 &sa->vxrs_low, sizeof(sa->vxrs_low)); 383 } 384 return ptr; 385 } 386 387 /* 388 * Calculate size of ELF notes per cpu 389 */ 390 static size_t get_cpu_elf_notes_size(void) 391 { 392 struct save_area *sa = NULL; 393 size_t size; 394 395 size = nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus)); 396 size += nt_size(NT_PRFPREG, sizeof(elf_fpregset_t)); 397 size += nt_size(NT_S390_TIMER, sizeof(sa->timer)); 398 size += nt_size(NT_S390_TODCMP, sizeof(sa->todcmp)); 399 size += nt_size(NT_S390_TODPREG, sizeof(sa->todpreg)); 400 size += nt_size(NT_S390_CTRS, sizeof(sa->ctrs)); 401 size += nt_size(NT_S390_PREFIX, sizeof(sa->prefix)); 402 if (MACHINE_HAS_VX) { 403 size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high)); 404 size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low)); 405 } 406 407 return size; 408 } 409 410 /* 411 * Initialize prpsinfo note (new kernel) 412 */ 413 static void *nt_prpsinfo(void *ptr) 414 { 415 struct elf_prpsinfo prpsinfo; 416 417 memset(&prpsinfo, 0, sizeof(prpsinfo)); 418 prpsinfo.pr_sname = 'R'; 419 strcpy(prpsinfo.pr_fname, "vmlinux"); 420 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo)); 421 } 422 423 /* 424 * Get vmcoreinfo using lowcore->vmcore_info (new kernel) 425 */ 426 static void *get_vmcoreinfo_old(unsigned long *size) 427 { 428 char nt_name[11], *vmcoreinfo; 429 Elf64_Nhdr note; 430 void *addr; 431 432 if (copy_oldmem_kernel(&addr, &S390_lowcore.vmcore_info, sizeof(addr))) 433 return NULL; 434 memset(nt_name, 0, sizeof(nt_name)); 435 if (copy_oldmem_kernel(¬e, addr, sizeof(note))) 436 return NULL; 437 if (copy_oldmem_kernel(nt_name, addr + sizeof(note), 438 sizeof(nt_name) - 1)) 439 return NULL; 440 if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0) 441 return NULL; 442 vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL); 443 if (!vmcoreinfo) 444 return NULL; 445 if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) { 446 kfree(vmcoreinfo); 447 return NULL; 448 } 449 *size = note.n_descsz; 450 return vmcoreinfo; 451 } 452 453 /* 454 * Initialize vmcoreinfo note (new kernel) 455 */ 456 static void *nt_vmcoreinfo(void *ptr) 457 { 458 const char *name = VMCOREINFO_NOTE_NAME; 459 unsigned long size; 460 void *vmcoreinfo; 461 462 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); 463 if (vmcoreinfo) 464 return nt_init_name(ptr, 0, vmcoreinfo, size, name); 465 466 vmcoreinfo = get_vmcoreinfo_old(&size); 467 if (!vmcoreinfo) 468 return ptr; 469 ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name); 470 kfree(vmcoreinfo); 471 return ptr; 472 } 473 474 static size_t nt_vmcoreinfo_size(void) 475 { 476 const char *name = VMCOREINFO_NOTE_NAME; 477 unsigned long size; 478 void *vmcoreinfo; 479 480 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); 481 if (vmcoreinfo) 482 return nt_size_name(size, name); 483 484 vmcoreinfo = get_vmcoreinfo_old(&size); 485 if (!vmcoreinfo) 486 return 0; 487 488 kfree(vmcoreinfo); 489 return nt_size_name(size, name); 490 } 491 492 /* 493 * Initialize final note (needed for /proc/vmcore code) 494 */ 495 static void *nt_final(void *ptr) 496 { 497 Elf64_Nhdr *note; 498 499 note = (Elf64_Nhdr *) ptr; 500 note->n_namesz = 0; 501 note->n_descsz = 0; 502 note->n_type = 0; 503 return PTR_ADD(ptr, sizeof(Elf64_Nhdr)); 504 } 505 506 /* 507 * Initialize ELF header (new kernel) 508 */ 509 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt) 510 { 511 memset(ehdr, 0, sizeof(*ehdr)); 512 memcpy(ehdr->e_ident, ELFMAG, SELFMAG); 513 ehdr->e_ident[EI_CLASS] = ELFCLASS64; 514 ehdr->e_ident[EI_DATA] = ELFDATA2MSB; 515 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 516 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); 517 ehdr->e_type = ET_CORE; 518 ehdr->e_machine = EM_S390; 519 ehdr->e_version = EV_CURRENT; 520 ehdr->e_phoff = sizeof(Elf64_Ehdr); 521 ehdr->e_ehsize = sizeof(Elf64_Ehdr); 522 ehdr->e_phentsize = sizeof(Elf64_Phdr); 523 ehdr->e_phnum = mem_chunk_cnt + 1; 524 return ehdr + 1; 525 } 526 527 /* 528 * Return CPU count for ELF header (new kernel) 529 */ 530 static int get_cpu_cnt(void) 531 { 532 struct save_area *sa; 533 int cpus = 0; 534 535 list_for_each_entry(sa, &dump_save_areas, list) 536 if (sa->prefix != 0) 537 cpus++; 538 return cpus; 539 } 540 541 /* 542 * Return memory chunk count for ELF header (new kernel) 543 */ 544 static int get_mem_chunk_cnt(void) 545 { 546 int cnt = 0; 547 u64 idx; 548 549 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE, 550 MEMBLOCK_NONE, NULL, NULL, NULL) 551 cnt++; 552 return cnt; 553 } 554 555 /* 556 * Initialize ELF loads (new kernel) 557 */ 558 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset) 559 { 560 phys_addr_t start, end; 561 u64 idx; 562 563 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE, 564 MEMBLOCK_NONE, &start, &end, NULL) { 565 phdr->p_filesz = end - start; 566 phdr->p_type = PT_LOAD; 567 phdr->p_offset = start; 568 phdr->p_vaddr = start; 569 phdr->p_paddr = start; 570 phdr->p_memsz = end - start; 571 phdr->p_flags = PF_R | PF_W | PF_X; 572 phdr->p_align = PAGE_SIZE; 573 phdr++; 574 } 575 } 576 577 /* 578 * Initialize notes (new kernel) 579 */ 580 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset) 581 { 582 struct save_area *sa; 583 void *ptr_start = ptr; 584 int cpu; 585 586 ptr = nt_prpsinfo(ptr); 587 588 cpu = 1; 589 list_for_each_entry(sa, &dump_save_areas, list) 590 if (sa->prefix != 0) 591 ptr = fill_cpu_elf_notes(ptr, cpu++, sa); 592 ptr = nt_vmcoreinfo(ptr); 593 ptr = nt_final(ptr); 594 memset(phdr, 0, sizeof(*phdr)); 595 phdr->p_type = PT_NOTE; 596 phdr->p_offset = notes_offset; 597 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start); 598 phdr->p_memsz = phdr->p_filesz; 599 return ptr; 600 } 601 602 static size_t get_elfcorehdr_size(int mem_chunk_cnt) 603 { 604 size_t size; 605 606 size = sizeof(Elf64_Ehdr); 607 /* PT_NOTES */ 608 size += sizeof(Elf64_Phdr); 609 /* nt_prpsinfo */ 610 size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo)); 611 /* regsets */ 612 size += get_cpu_cnt() * get_cpu_elf_notes_size(); 613 /* nt_vmcoreinfo */ 614 size += nt_vmcoreinfo_size(); 615 /* nt_final */ 616 size += sizeof(Elf64_Nhdr); 617 /* PT_LOADS */ 618 size += mem_chunk_cnt * sizeof(Elf64_Phdr); 619 620 return size; 621 } 622 623 /* 624 * Create ELF core header (new kernel) 625 */ 626 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size) 627 { 628 Elf64_Phdr *phdr_notes, *phdr_loads; 629 int mem_chunk_cnt; 630 void *ptr, *hdr; 631 u32 alloc_size; 632 u64 hdr_off; 633 634 /* If we are not in kdump or zfcpdump mode return */ 635 if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP) 636 return 0; 637 /* If we cannot get HSA size for zfcpdump return error */ 638 if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp.hsa_size) 639 return -ENODEV; 640 641 /* For kdump, exclude previous crashkernel memory */ 642 if (OLDMEM_BASE) { 643 oldmem_region.base = OLDMEM_BASE; 644 oldmem_region.size = OLDMEM_SIZE; 645 oldmem_type.total_size = OLDMEM_SIZE; 646 } 647 648 mem_chunk_cnt = get_mem_chunk_cnt(); 649 650 alloc_size = get_elfcorehdr_size(mem_chunk_cnt); 651 652 hdr = kzalloc(alloc_size, GFP_KERNEL); 653 654 /* Without elfcorehdr /proc/vmcore cannot be created. Thus creating 655 * a dump with this crash kernel will fail. Panic now to allow other 656 * dump mechanisms to take over. 657 */ 658 if (!hdr) 659 panic("s390 kdump allocating elfcorehdr failed"); 660 661 /* Init elf header */ 662 ptr = ehdr_init(hdr, mem_chunk_cnt); 663 /* Init program headers */ 664 phdr_notes = ptr; 665 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr)); 666 phdr_loads = ptr; 667 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt); 668 /* Init notes */ 669 hdr_off = PTR_DIFF(ptr, hdr); 670 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off); 671 /* Init loads */ 672 hdr_off = PTR_DIFF(ptr, hdr); 673 loads_init(phdr_loads, hdr_off); 674 *addr = (unsigned long long) hdr; 675 *size = (unsigned long long) hdr_off; 676 BUG_ON(elfcorehdr_size > alloc_size); 677 return 0; 678 } 679 680 /* 681 * Free ELF core header (new kernel) 682 */ 683 void elfcorehdr_free(unsigned long long addr) 684 { 685 kfree((void *)(unsigned long)addr); 686 } 687 688 /* 689 * Read from ELF header 690 */ 691 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) 692 { 693 void *src = (void *)(unsigned long)*ppos; 694 695 memcpy(buf, src, count); 696 *ppos += count; 697 return count; 698 } 699 700 /* 701 * Read from ELF notes data 702 */ 703 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) 704 { 705 void *src = (void *)(unsigned long)*ppos; 706 707 memcpy(buf, src, count); 708 *ppos += count; 709 return count; 710 } 711