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 <linux/uio.h> 19 #include <asm/asm-offsets.h> 20 #include <asm/os_info.h> 21 #include <asm/elf.h> 22 #include <asm/ipl.h> 23 #include <asm/sclp.h> 24 25 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y))) 26 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y))) 27 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y)))) 28 29 static struct memblock_region oldmem_region; 30 31 static struct memblock_type oldmem_type = { 32 .cnt = 1, 33 .max = 1, 34 .total_size = 0, 35 .regions = &oldmem_region, 36 .name = "oldmem", 37 }; 38 39 struct save_area { 40 struct list_head list; 41 u64 psw[2]; 42 u64 ctrs[16]; 43 u64 gprs[16]; 44 u32 acrs[16]; 45 u64 fprs[16]; 46 u32 fpc; 47 u32 prefix; 48 u64 todpreg; 49 u64 timer; 50 u64 todcmp; 51 u64 vxrs_low[16]; 52 __vector128 vxrs_high[16]; 53 }; 54 55 static LIST_HEAD(dump_save_areas); 56 57 /* 58 * Allocate a save area 59 */ 60 struct save_area * __init save_area_alloc(bool is_boot_cpu) 61 { 62 struct save_area *sa; 63 64 sa = memblock_alloc(sizeof(*sa), 8); 65 if (!sa) 66 panic("Failed to allocate save area\n"); 67 68 if (is_boot_cpu) 69 list_add(&sa->list, &dump_save_areas); 70 else 71 list_add_tail(&sa->list, &dump_save_areas); 72 return sa; 73 } 74 75 /* 76 * Return the address of the save area for the boot CPU 77 */ 78 struct save_area * __init save_area_boot_cpu(void) 79 { 80 return list_first_entry_or_null(&dump_save_areas, struct save_area, list); 81 } 82 83 /* 84 * Copy CPU registers into the save area 85 */ 86 void __init save_area_add_regs(struct save_area *sa, void *regs) 87 { 88 struct lowcore *lc; 89 90 lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA); 91 memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw)); 92 memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs)); 93 memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs)); 94 memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs)); 95 memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs)); 96 memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc)); 97 memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix)); 98 memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg)); 99 memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer)); 100 memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp)); 101 } 102 103 /* 104 * Copy vector registers into the save area 105 */ 106 void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs) 107 { 108 int i; 109 110 /* Copy lower halves of vector registers 0-15 */ 111 for (i = 0; i < 16; i++) 112 memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8); 113 /* Copy vector registers 16-31 */ 114 memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128)); 115 } 116 117 /* 118 * Return physical address for virtual address 119 */ 120 static inline void *load_real_addr(void *addr) 121 { 122 unsigned long real_addr; 123 124 asm volatile( 125 " lra %0,0(%1)\n" 126 " jz 0f\n" 127 " la %0,0\n" 128 "0:" 129 : "=a" (real_addr) : "a" (addr) : "cc"); 130 return (void *)real_addr; 131 } 132 133 /* 134 * Copy memory of the old, dumped system to a kernel space virtual address 135 */ 136 int copy_oldmem_kernel(void *dst, unsigned long src, size_t count) 137 { 138 unsigned long len; 139 void *ra; 140 int rc; 141 142 while (count) { 143 if (!oldmem_data.start && src < sclp.hsa_size) { 144 /* Copy from zfcp/nvme dump HSA area */ 145 len = min(count, sclp.hsa_size - src); 146 rc = memcpy_hsa_kernel(dst, src, len); 147 if (rc) 148 return rc; 149 } else { 150 /* Check for swapped kdump oldmem areas */ 151 if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) { 152 src -= oldmem_data.start; 153 len = min(count, oldmem_data.size - src); 154 } else if (oldmem_data.start && src < oldmem_data.size) { 155 len = min(count, oldmem_data.size - src); 156 src += oldmem_data.start; 157 } else { 158 len = count; 159 } 160 if (is_vmalloc_or_module_addr(dst)) { 161 ra = load_real_addr(dst); 162 len = min(PAGE_SIZE - offset_in_page(ra), len); 163 } else { 164 ra = dst; 165 } 166 if (memcpy_real(ra, src, len)) 167 return -EFAULT; 168 } 169 dst += len; 170 src += len; 171 count -= len; 172 } 173 return 0; 174 } 175 176 /* 177 * Copy memory of the old, dumped system to a user space virtual address 178 */ 179 static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count) 180 { 181 unsigned long len; 182 int rc; 183 184 while (count) { 185 if (!oldmem_data.start && src < sclp.hsa_size) { 186 /* Copy from zfcp/nvme dump HSA area */ 187 len = min(count, sclp.hsa_size - src); 188 rc = memcpy_hsa_user(dst, src, len); 189 if (rc) 190 return rc; 191 } else { 192 /* Check for swapped kdump oldmem areas */ 193 if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) { 194 src -= oldmem_data.start; 195 len = min(count, oldmem_data.size - src); 196 } else if (oldmem_data.start && src < oldmem_data.size) { 197 len = min(count, oldmem_data.size - src); 198 src += oldmem_data.start; 199 } else { 200 len = count; 201 } 202 rc = copy_to_user_real(dst, src, count); 203 if (rc) 204 return rc; 205 } 206 dst += len; 207 src += len; 208 count -= len; 209 } 210 return 0; 211 } 212 213 /* 214 * Copy one page from "oldmem" 215 */ 216 ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, 217 unsigned long offset) 218 { 219 unsigned long src; 220 int rc; 221 222 if (!(iter_is_iovec(iter) || iov_iter_is_kvec(iter))) 223 return -EINVAL; 224 /* Multi-segment iterators are not supported */ 225 if (iter->nr_segs > 1) 226 return -EINVAL; 227 if (!csize) 228 return 0; 229 src = pfn_to_phys(pfn) + offset; 230 231 /* XXX: pass the iov_iter down to a common function */ 232 if (iter_is_iovec(iter)) 233 rc = copy_oldmem_user(iter->iov->iov_base, src, csize); 234 else 235 rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize); 236 if (rc < 0) 237 return rc; 238 iov_iter_advance(iter, csize); 239 return csize; 240 } 241 242 /* 243 * Remap "oldmem" for kdump 244 * 245 * For the kdump reserved memory this functions performs a swap operation: 246 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] 247 */ 248 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma, 249 unsigned long from, unsigned long pfn, 250 unsigned long size, pgprot_t prot) 251 { 252 unsigned long size_old; 253 int rc; 254 255 if (pfn < oldmem_data.size >> PAGE_SHIFT) { 256 size_old = min(size, oldmem_data.size - (pfn << PAGE_SHIFT)); 257 rc = remap_pfn_range(vma, from, 258 pfn + (oldmem_data.start >> PAGE_SHIFT), 259 size_old, prot); 260 if (rc || size == size_old) 261 return rc; 262 size -= size_old; 263 from += size_old; 264 pfn += size_old >> PAGE_SHIFT; 265 } 266 return remap_pfn_range(vma, from, pfn, size, prot); 267 } 268 269 /* 270 * Remap "oldmem" for zfcp/nvme dump 271 * 272 * We only map available memory above HSA size. Memory below HSA size 273 * is read on demand using the copy_oldmem_page() function. 274 */ 275 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma, 276 unsigned long from, 277 unsigned long pfn, 278 unsigned long size, pgprot_t prot) 279 { 280 unsigned long hsa_end = sclp.hsa_size; 281 unsigned long size_hsa; 282 283 if (pfn < hsa_end >> PAGE_SHIFT) { 284 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT)); 285 if (size == size_hsa) 286 return 0; 287 size -= size_hsa; 288 from += size_hsa; 289 pfn += size_hsa >> PAGE_SHIFT; 290 } 291 return remap_pfn_range(vma, from, pfn, size, prot); 292 } 293 294 /* 295 * Remap "oldmem" for kdump or zfcp/nvme dump 296 */ 297 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from, 298 unsigned long pfn, unsigned long size, pgprot_t prot) 299 { 300 if (oldmem_data.start) 301 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot); 302 else 303 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size, 304 prot); 305 } 306 307 static const char *nt_name(Elf64_Word type) 308 { 309 const char *name = "LINUX"; 310 311 if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG) 312 name = KEXEC_CORE_NOTE_NAME; 313 return name; 314 } 315 316 /* 317 * Initialize ELF note 318 */ 319 static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len, 320 const char *name) 321 { 322 Elf64_Nhdr *note; 323 u64 len; 324 325 note = (Elf64_Nhdr *)buf; 326 note->n_namesz = strlen(name) + 1; 327 note->n_descsz = d_len; 328 note->n_type = type; 329 len = sizeof(Elf64_Nhdr); 330 331 memcpy(buf + len, name, note->n_namesz); 332 len = roundup(len + note->n_namesz, 4); 333 334 memcpy(buf + len, desc, note->n_descsz); 335 len = roundup(len + note->n_descsz, 4); 336 337 return PTR_ADD(buf, len); 338 } 339 340 static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len) 341 { 342 return nt_init_name(buf, type, desc, d_len, nt_name(type)); 343 } 344 345 /* 346 * Calculate the size of ELF note 347 */ 348 static size_t nt_size_name(int d_len, const char *name) 349 { 350 size_t size; 351 352 size = sizeof(Elf64_Nhdr); 353 size += roundup(strlen(name) + 1, 4); 354 size += roundup(d_len, 4); 355 356 return size; 357 } 358 359 static inline size_t nt_size(Elf64_Word type, int d_len) 360 { 361 return nt_size_name(d_len, nt_name(type)); 362 } 363 364 /* 365 * Fill ELF notes for one CPU with save area registers 366 */ 367 static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa) 368 { 369 struct elf_prstatus nt_prstatus; 370 elf_fpregset_t nt_fpregset; 371 372 /* Prepare prstatus note */ 373 memset(&nt_prstatus, 0, sizeof(nt_prstatus)); 374 memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs)); 375 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw)); 376 memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs)); 377 nt_prstatus.common.pr_pid = cpu; 378 /* Prepare fpregset (floating point) note */ 379 memset(&nt_fpregset, 0, sizeof(nt_fpregset)); 380 memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc)); 381 memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs)); 382 /* Create ELF notes for the CPU */ 383 ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus)); 384 ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset)); 385 ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer)); 386 ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp)); 387 ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg)); 388 ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs)); 389 ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix)); 390 if (MACHINE_HAS_VX) { 391 ptr = nt_init(ptr, NT_S390_VXRS_HIGH, 392 &sa->vxrs_high, sizeof(sa->vxrs_high)); 393 ptr = nt_init(ptr, NT_S390_VXRS_LOW, 394 &sa->vxrs_low, sizeof(sa->vxrs_low)); 395 } 396 return ptr; 397 } 398 399 /* 400 * Calculate size of ELF notes per cpu 401 */ 402 static size_t get_cpu_elf_notes_size(void) 403 { 404 struct save_area *sa = NULL; 405 size_t size; 406 407 size = nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus)); 408 size += nt_size(NT_PRFPREG, sizeof(elf_fpregset_t)); 409 size += nt_size(NT_S390_TIMER, sizeof(sa->timer)); 410 size += nt_size(NT_S390_TODCMP, sizeof(sa->todcmp)); 411 size += nt_size(NT_S390_TODPREG, sizeof(sa->todpreg)); 412 size += nt_size(NT_S390_CTRS, sizeof(sa->ctrs)); 413 size += nt_size(NT_S390_PREFIX, sizeof(sa->prefix)); 414 if (MACHINE_HAS_VX) { 415 size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high)); 416 size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low)); 417 } 418 419 return size; 420 } 421 422 /* 423 * Initialize prpsinfo note (new kernel) 424 */ 425 static void *nt_prpsinfo(void *ptr) 426 { 427 struct elf_prpsinfo prpsinfo; 428 429 memset(&prpsinfo, 0, sizeof(prpsinfo)); 430 prpsinfo.pr_sname = 'R'; 431 strcpy(prpsinfo.pr_fname, "vmlinux"); 432 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo)); 433 } 434 435 /* 436 * Get vmcoreinfo using lowcore->vmcore_info (new kernel) 437 */ 438 static void *get_vmcoreinfo_old(unsigned long *size) 439 { 440 char nt_name[11], *vmcoreinfo; 441 unsigned long addr; 442 Elf64_Nhdr note; 443 444 if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr))) 445 return NULL; 446 memset(nt_name, 0, sizeof(nt_name)); 447 if (copy_oldmem_kernel(¬e, addr, sizeof(note))) 448 return NULL; 449 if (copy_oldmem_kernel(nt_name, addr + sizeof(note), 450 sizeof(nt_name) - 1)) 451 return NULL; 452 if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0) 453 return NULL; 454 vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL); 455 if (!vmcoreinfo) 456 return NULL; 457 if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) { 458 kfree(vmcoreinfo); 459 return NULL; 460 } 461 *size = note.n_descsz; 462 return vmcoreinfo; 463 } 464 465 /* 466 * Initialize vmcoreinfo note (new kernel) 467 */ 468 static void *nt_vmcoreinfo(void *ptr) 469 { 470 const char *name = VMCOREINFO_NOTE_NAME; 471 unsigned long size; 472 void *vmcoreinfo; 473 474 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); 475 if (vmcoreinfo) 476 return nt_init_name(ptr, 0, vmcoreinfo, size, name); 477 478 vmcoreinfo = get_vmcoreinfo_old(&size); 479 if (!vmcoreinfo) 480 return ptr; 481 ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name); 482 kfree(vmcoreinfo); 483 return ptr; 484 } 485 486 static size_t nt_vmcoreinfo_size(void) 487 { 488 const char *name = VMCOREINFO_NOTE_NAME; 489 unsigned long size; 490 void *vmcoreinfo; 491 492 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); 493 if (vmcoreinfo) 494 return nt_size_name(size, name); 495 496 vmcoreinfo = get_vmcoreinfo_old(&size); 497 if (!vmcoreinfo) 498 return 0; 499 500 kfree(vmcoreinfo); 501 return nt_size_name(size, name); 502 } 503 504 /* 505 * Initialize final note (needed for /proc/vmcore code) 506 */ 507 static void *nt_final(void *ptr) 508 { 509 Elf64_Nhdr *note; 510 511 note = (Elf64_Nhdr *) ptr; 512 note->n_namesz = 0; 513 note->n_descsz = 0; 514 note->n_type = 0; 515 return PTR_ADD(ptr, sizeof(Elf64_Nhdr)); 516 } 517 518 /* 519 * Initialize ELF header (new kernel) 520 */ 521 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt) 522 { 523 memset(ehdr, 0, sizeof(*ehdr)); 524 memcpy(ehdr->e_ident, ELFMAG, SELFMAG); 525 ehdr->e_ident[EI_CLASS] = ELFCLASS64; 526 ehdr->e_ident[EI_DATA] = ELFDATA2MSB; 527 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 528 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); 529 ehdr->e_type = ET_CORE; 530 ehdr->e_machine = EM_S390; 531 ehdr->e_version = EV_CURRENT; 532 ehdr->e_phoff = sizeof(Elf64_Ehdr); 533 ehdr->e_ehsize = sizeof(Elf64_Ehdr); 534 ehdr->e_phentsize = sizeof(Elf64_Phdr); 535 ehdr->e_phnum = mem_chunk_cnt + 1; 536 return ehdr + 1; 537 } 538 539 /* 540 * Return CPU count for ELF header (new kernel) 541 */ 542 static int get_cpu_cnt(void) 543 { 544 struct save_area *sa; 545 int cpus = 0; 546 547 list_for_each_entry(sa, &dump_save_areas, list) 548 if (sa->prefix != 0) 549 cpus++; 550 return cpus; 551 } 552 553 /* 554 * Return memory chunk count for ELF header (new kernel) 555 */ 556 static int get_mem_chunk_cnt(void) 557 { 558 int cnt = 0; 559 u64 idx; 560 561 for_each_physmem_range(idx, &oldmem_type, NULL, NULL) 562 cnt++; 563 return cnt; 564 } 565 566 /* 567 * Initialize ELF loads (new kernel) 568 */ 569 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset) 570 { 571 phys_addr_t start, end; 572 u64 idx; 573 574 for_each_physmem_range(idx, &oldmem_type, &start, &end) { 575 phdr->p_filesz = end - start; 576 phdr->p_type = PT_LOAD; 577 phdr->p_offset = start; 578 phdr->p_vaddr = start; 579 phdr->p_paddr = start; 580 phdr->p_memsz = end - start; 581 phdr->p_flags = PF_R | PF_W | PF_X; 582 phdr->p_align = PAGE_SIZE; 583 phdr++; 584 } 585 } 586 587 /* 588 * Initialize notes (new kernel) 589 */ 590 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset) 591 { 592 struct save_area *sa; 593 void *ptr_start = ptr; 594 int cpu; 595 596 ptr = nt_prpsinfo(ptr); 597 598 cpu = 1; 599 list_for_each_entry(sa, &dump_save_areas, list) 600 if (sa->prefix != 0) 601 ptr = fill_cpu_elf_notes(ptr, cpu++, sa); 602 ptr = nt_vmcoreinfo(ptr); 603 ptr = nt_final(ptr); 604 memset(phdr, 0, sizeof(*phdr)); 605 phdr->p_type = PT_NOTE; 606 phdr->p_offset = notes_offset; 607 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start); 608 phdr->p_memsz = phdr->p_filesz; 609 return ptr; 610 } 611 612 static size_t get_elfcorehdr_size(int mem_chunk_cnt) 613 { 614 size_t size; 615 616 size = sizeof(Elf64_Ehdr); 617 /* PT_NOTES */ 618 size += sizeof(Elf64_Phdr); 619 /* nt_prpsinfo */ 620 size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo)); 621 /* regsets */ 622 size += get_cpu_cnt() * get_cpu_elf_notes_size(); 623 /* nt_vmcoreinfo */ 624 size += nt_vmcoreinfo_size(); 625 /* nt_final */ 626 size += sizeof(Elf64_Nhdr); 627 /* PT_LOADS */ 628 size += mem_chunk_cnt * sizeof(Elf64_Phdr); 629 630 return size; 631 } 632 633 /* 634 * Create ELF core header (new kernel) 635 */ 636 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size) 637 { 638 Elf64_Phdr *phdr_notes, *phdr_loads; 639 int mem_chunk_cnt; 640 void *ptr, *hdr; 641 u32 alloc_size; 642 u64 hdr_off; 643 644 /* If we are not in kdump or zfcp/nvme dump mode return */ 645 if (!oldmem_data.start && !is_ipl_type_dump()) 646 return 0; 647 /* If we cannot get HSA size for zfcp/nvme dump return error */ 648 if (is_ipl_type_dump() && !sclp.hsa_size) 649 return -ENODEV; 650 651 /* For kdump, exclude previous crashkernel memory */ 652 if (oldmem_data.start) { 653 oldmem_region.base = oldmem_data.start; 654 oldmem_region.size = oldmem_data.size; 655 oldmem_type.total_size = oldmem_data.size; 656 } 657 658 mem_chunk_cnt = get_mem_chunk_cnt(); 659 660 alloc_size = get_elfcorehdr_size(mem_chunk_cnt); 661 662 hdr = kzalloc(alloc_size, GFP_KERNEL); 663 664 /* Without elfcorehdr /proc/vmcore cannot be created. Thus creating 665 * a dump with this crash kernel will fail. Panic now to allow other 666 * dump mechanisms to take over. 667 */ 668 if (!hdr) 669 panic("s390 kdump allocating elfcorehdr failed"); 670 671 /* Init elf header */ 672 ptr = ehdr_init(hdr, mem_chunk_cnt); 673 /* Init program headers */ 674 phdr_notes = ptr; 675 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr)); 676 phdr_loads = ptr; 677 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt); 678 /* Init notes */ 679 hdr_off = PTR_DIFF(ptr, hdr); 680 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off); 681 /* Init loads */ 682 hdr_off = PTR_DIFF(ptr, hdr); 683 loads_init(phdr_loads, hdr_off); 684 *addr = (unsigned long long) hdr; 685 *size = (unsigned long long) hdr_off; 686 BUG_ON(elfcorehdr_size > alloc_size); 687 return 0; 688 } 689 690 /* 691 * Free ELF core header (new kernel) 692 */ 693 void elfcorehdr_free(unsigned long long addr) 694 { 695 kfree((void *)(unsigned long)addr); 696 } 697 698 /* 699 * Read from ELF header 700 */ 701 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) 702 { 703 void *src = (void *)(unsigned long)*ppos; 704 705 memcpy(buf, src, count); 706 *ppos += count; 707 return count; 708 } 709 710 /* 711 * Read from ELF notes data 712 */ 713 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) 714 { 715 void *src = (void *)(unsigned long)*ppos; 716 717 memcpy(buf, src, count); 718 *ppos += count; 719 return count; 720 } 721