root/arch/s390/kernel/crash_dump.c

DEFINITIONS

1. save_area_alloc
2. save_area_boot_cpu
3. save_area_add_regs
4. save_area_add_vxrs
5. load_real_addr
6. copy_oldmem_kernel
7. copy_oldmem_user
8. copy_oldmem_page
9. remap_oldmem_pfn_range_kdump
10. remap_oldmem_pfn_range_zfcpdump
11. remap_oldmem_pfn_range
12. nt_name
13. nt_init_name
14. nt_init
15. nt_size_name
16. nt_size
17. fill_cpu_elf_notes
18. get_cpu_elf_notes_size
19. nt_prpsinfo
20. get_vmcoreinfo_old
21. nt_vmcoreinfo
22. nt_vmcoreinfo_size
23. nt_final
24. ehdr_init
25. get_cpu_cnt
26. get_mem_chunk_cnt
27. loads_init
28. notes_init
29. get_elfcorehdr_size
30. elfcorehdr_alloc
31. elfcorehdr_free
32. elfcorehdr_read
33. elfcorehdr_read_notes

   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 (!sa)
  65                 panic("Failed to allocate save area\n");
  66 
  67         if (is_boot_cpu)
  68                 list_add(&sa->list, &dump_save_areas);
  69         else
  70                 list_add_tail(&sa->list, &dump_save_areas);
  71         return sa;
  72 }
  73 
  74 /*
  75  * Return the address of the save area for the boot CPU
  76  */
  77 struct save_area * __init save_area_boot_cpu(void)
  78 {
  79         return list_first_entry_or_null(&dump_save_areas, struct save_area, list);
  80 }
  81 
  82 /*
  83  * Copy CPU registers into the save area
  84  */
  85 void __init save_area_add_regs(struct save_area *sa, void *regs)
  86 {
  87         struct lowcore *lc;
  88 
  89         lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA);
  90         memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw));
  91         memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs));
  92         memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs));
  93         memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs));
  94         memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs));
  95         memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc));
  96         memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix));
  97         memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg));
  98         memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer));
  99         memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp));
 100 }
 101 
 102 /*
 103  * Copy vector registers into the save area
 104  */
 105 void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
 106 {
 107         int i;
 108 
 109         /* Copy lower halves of vector registers 0-15 */
 110         for (i = 0; i < 16; i++)
 111                 memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8);
 112         /* Copy vector registers 16-31 */
 113         memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
 114 }
 115 
 116 /*
 117  * Return physical address for virtual address
 118  */
 119 static inline void *load_real_addr(void *addr)
 120 {
 121         unsigned long real_addr;
 122 
 123         asm volatile(
 124                    "    lra     %0,0(%1)\n"
 125                    "    jz      0f\n"
 126                    "    la      %0,0\n"
 127                    "0:"
 128                    : "=a" (real_addr) : "a" (addr) : "cc");
 129         return (void *)real_addr;
 130 }
 131 
 132 /*
 133  * Copy memory of the old, dumped system to a kernel space virtual address
 134  */
 135 int copy_oldmem_kernel(void *dst, void *src, size_t count)
 136 {
 137         unsigned long from, len;
 138         void *ra;
 139         int rc;
 140 
 141         while (count) {
 142                 from = __pa(src);
 143                 if (!OLDMEM_BASE && from < sclp.hsa_size) {
 144                         /* Copy from zfcpdump HSA area */
 145                         len = min(count, sclp.hsa_size - from);
 146                         rc = memcpy_hsa_kernel(dst, from, len);
 147                         if (rc)
 148                                 return rc;
 149                 } else {
 150                         /* Check for swapped kdump oldmem areas */
 151                         if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) {
 152                                 from -= OLDMEM_BASE;
 153                                 len = min(count, OLDMEM_SIZE - from);
 154                         } else if (OLDMEM_BASE && from < OLDMEM_SIZE) {
 155                                 len = min(count, OLDMEM_SIZE - from);
 156                                 from += OLDMEM_BASE;
 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, (void *) from, 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, void *src, size_t count)
 180 {
 181         unsigned long from, len;
 182         int rc;
 183 
 184         while (count) {
 185                 from = __pa(src);
 186                 if (!OLDMEM_BASE && from < sclp.hsa_size) {
 187                         /* Copy from zfcpdump HSA area */
 188                         len = min(count, sclp.hsa_size - from);
 189                         rc = memcpy_hsa_user(dst, from, len);
 190                         if (rc)
 191                                 return rc;
 192                 } else {
 193                         /* Check for swapped kdump oldmem areas */
 194                         if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) {
 195                                 from -= OLDMEM_BASE;
 196                                 len = min(count, OLDMEM_SIZE - from);
 197                         } else if (OLDMEM_BASE && from < OLDMEM_SIZE) {
 198                                 len = min(count, OLDMEM_SIZE - from);
 199                                 from += OLDMEM_BASE;
 200                         } else {
 201                                 len = count;
 202                         }
 203                         rc = copy_to_user_real(dst, (void *) from, count);
 204                         if (rc)
 205                                 return rc;
 206                 }
 207                 dst += len;
 208                 src += len;
 209                 count -= len;
 210         }
 211         return 0;
 212 }
 213 
 214 /*
 215  * Copy one page from "oldmem"
 216  */
 217 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 218                          unsigned long offset, int userbuf)
 219 {
 220         void *src;
 221         int rc;
 222 
 223         if (!csize)
 224                 return 0;
 225         src = (void *) (pfn << PAGE_SHIFT) + offset;
 226         if (userbuf)
 227                 rc = copy_oldmem_user((void __force __user *) buf, src, csize);
 228         else
 229                 rc = copy_oldmem_kernel((void *) buf, src, csize);
 230         return rc;
 231 }
 232 
 233 /*
 234  * Remap "oldmem" for kdump
 235  *
 236  * For the kdump reserved memory this functions performs a swap operation:
 237  * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
 238  */
 239 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
 240                                         unsigned long from, unsigned long pfn,
 241                                         unsigned long size, pgprot_t prot)
 242 {
 243         unsigned long size_old;
 244         int rc;
 245 
 246         if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
 247                 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
 248                 rc = remap_pfn_range(vma, from,
 249                                      pfn + (OLDMEM_BASE >> PAGE_SHIFT),
 250                                      size_old, prot);
 251                 if (rc || size == size_old)
 252                         return rc;
 253                 size -= size_old;
 254                 from += size_old;
 255                 pfn += size_old >> PAGE_SHIFT;
 256         }
 257         return remap_pfn_range(vma, from, pfn, size, prot);
 258 }
 259 
 260 /*
 261  * Remap "oldmem" for zfcpdump
 262  *
 263  * We only map available memory above HSA size. Memory below HSA size
 264  * is read on demand using the copy_oldmem_page() function.
 265  */
 266 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
 267                                            unsigned long from,
 268                                            unsigned long pfn,
 269                                            unsigned long size, pgprot_t prot)
 270 {
 271         unsigned long hsa_end = sclp.hsa_size;
 272         unsigned long size_hsa;
 273 
 274         if (pfn < hsa_end >> PAGE_SHIFT) {
 275                 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
 276                 if (size == size_hsa)
 277                         return 0;
 278                 size -= size_hsa;
 279                 from += size_hsa;
 280                 pfn += size_hsa >> PAGE_SHIFT;
 281         }
 282         return remap_pfn_range(vma, from, pfn, size, prot);
 283 }
 284 
 285 /*
 286  * Remap "oldmem" for kdump or zfcpdump
 287  */
 288 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
 289                            unsigned long pfn, unsigned long size, pgprot_t prot)
 290 {
 291         if (OLDMEM_BASE)
 292                 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
 293         else
 294                 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
 295                                                        prot);
 296 }
 297 
 298 static const char *nt_name(Elf64_Word type)
 299 {
 300         const char *name = "LINUX";
 301 
 302         if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG)
 303                 name = KEXEC_CORE_NOTE_NAME;
 304         return name;
 305 }
 306 
 307 /*
 308  * Initialize ELF note
 309  */
 310 static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
 311                           const char *name)
 312 {
 313         Elf64_Nhdr *note;
 314         u64 len;
 315 
 316         note = (Elf64_Nhdr *)buf;
 317         note->n_namesz = strlen(name) + 1;
 318         note->n_descsz = d_len;
 319         note->n_type = type;
 320         len = sizeof(Elf64_Nhdr);
 321 
 322         memcpy(buf + len, name, note->n_namesz);
 323         len = roundup(len + note->n_namesz, 4);
 324 
 325         memcpy(buf + len, desc, note->n_descsz);
 326         len = roundup(len + note->n_descsz, 4);
 327 
 328         return PTR_ADD(buf, len);
 329 }
 330 
 331 static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
 332 {
 333         return nt_init_name(buf, type, desc, d_len, nt_name(type));
 334 }
 335 
 336 /*
 337  * Calculate the size of ELF note
 338  */
 339 static size_t nt_size_name(int d_len, const char *name)
 340 {
 341         size_t size;
 342 
 343         size = sizeof(Elf64_Nhdr);
 344         size += roundup(strlen(name) + 1, 4);
 345         size += roundup(d_len, 4);
 346 
 347         return size;
 348 }
 349 
 350 static inline size_t nt_size(Elf64_Word type, int d_len)
 351 {
 352         return nt_size_name(d_len, nt_name(type));
 353 }
 354 
 355 /*
 356  * Fill ELF notes for one CPU with save area registers
 357  */
 358 static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
 359 {
 360         struct elf_prstatus nt_prstatus;
 361         elf_fpregset_t nt_fpregset;
 362 
 363         /* Prepare prstatus note */
 364         memset(&nt_prstatus, 0, sizeof(nt_prstatus));
 365         memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
 366         memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
 367         memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
 368         nt_prstatus.pr_pid = cpu;
 369         /* Prepare fpregset (floating point) note */
 370         memset(&nt_fpregset, 0, sizeof(nt_fpregset));
 371         memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
 372         memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
 373         /* Create ELF notes for the CPU */
 374         ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
 375         ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
 376         ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
 377         ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
 378         ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
 379         ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
 380         ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
 381         if (MACHINE_HAS_VX) {
 382                 ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
 383                               &sa->vxrs_high, sizeof(sa->vxrs_high));
 384                 ptr = nt_init(ptr, NT_S390_VXRS_LOW,
 385                               &sa->vxrs_low, sizeof(sa->vxrs_low));
 386         }
 387         return ptr;
 388 }
 389 
 390 /*
 391  * Calculate size of ELF notes per cpu
 392  */
 393 static size_t get_cpu_elf_notes_size(void)
 394 {
 395         struct save_area *sa = NULL;
 396         size_t size;
 397 
 398         size =  nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus));
 399         size +=  nt_size(NT_PRFPREG, sizeof(elf_fpregset_t));
 400         size +=  nt_size(NT_S390_TIMER, sizeof(sa->timer));
 401         size +=  nt_size(NT_S390_TODCMP, sizeof(sa->todcmp));
 402         size +=  nt_size(NT_S390_TODPREG, sizeof(sa->todpreg));
 403         size +=  nt_size(NT_S390_CTRS, sizeof(sa->ctrs));
 404         size +=  nt_size(NT_S390_PREFIX, sizeof(sa->prefix));
 405         if (MACHINE_HAS_VX) {
 406                 size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high));
 407                 size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low));
 408         }
 409 
 410         return size;
 411 }
 412 
 413 /*
 414  * Initialize prpsinfo note (new kernel)
 415  */
 416 static void *nt_prpsinfo(void *ptr)
 417 {
 418         struct elf_prpsinfo prpsinfo;
 419 
 420         memset(&prpsinfo, 0, sizeof(prpsinfo));
 421         prpsinfo.pr_sname = 'R';
 422         strcpy(prpsinfo.pr_fname, "vmlinux");
 423         return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
 424 }
 425 
 426 /*
 427  * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
 428  */
 429 static void *get_vmcoreinfo_old(unsigned long *size)
 430 {
 431         char nt_name[11], *vmcoreinfo;
 432         Elf64_Nhdr note;
 433         void *addr;
 434 
 435         if (copy_oldmem_kernel(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
 436                 return NULL;
 437         memset(nt_name, 0, sizeof(nt_name));
 438         if (copy_oldmem_kernel(&note, addr, sizeof(note)))
 439                 return NULL;
 440         if (copy_oldmem_kernel(nt_name, addr + sizeof(note),
 441                                sizeof(nt_name) - 1))
 442                 return NULL;
 443         if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0)
 444                 return NULL;
 445         vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL);
 446         if (!vmcoreinfo)
 447                 return NULL;
 448         if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) {
 449                 kfree(vmcoreinfo);
 450                 return NULL;
 451         }
 452         *size = note.n_descsz;
 453         return vmcoreinfo;
 454 }
 455 
 456 /*
 457  * Initialize vmcoreinfo note (new kernel)
 458  */
 459 static void *nt_vmcoreinfo(void *ptr)
 460 {
 461         const char *name = VMCOREINFO_NOTE_NAME;
 462         unsigned long size;
 463         void *vmcoreinfo;
 464 
 465         vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
 466         if (vmcoreinfo)
 467                 return nt_init_name(ptr, 0, vmcoreinfo, size, name);
 468 
 469         vmcoreinfo = get_vmcoreinfo_old(&size);
 470         if (!vmcoreinfo)
 471                 return ptr;
 472         ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name);
 473         kfree(vmcoreinfo);
 474         return ptr;
 475 }
 476 
 477 static size_t nt_vmcoreinfo_size(void)
 478 {
 479         const char *name = VMCOREINFO_NOTE_NAME;
 480         unsigned long size;
 481         void *vmcoreinfo;
 482 
 483         vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
 484         if (vmcoreinfo)
 485                 return nt_size_name(size, name);
 486 
 487         vmcoreinfo = get_vmcoreinfo_old(&size);
 488         if (!vmcoreinfo)
 489                 return 0;
 490 
 491         kfree(vmcoreinfo);
 492         return nt_size_name(size, name);
 493 }
 494 
 495 /*
 496  * Initialize final note (needed for /proc/vmcore code)
 497  */
 498 static void *nt_final(void *ptr)
 499 {
 500         Elf64_Nhdr *note;
 501 
 502         note = (Elf64_Nhdr *) ptr;
 503         note->n_namesz = 0;
 504         note->n_descsz = 0;
 505         note->n_type = 0;
 506         return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
 507 }
 508 
 509 /*
 510  * Initialize ELF header (new kernel)
 511  */
 512 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
 513 {
 514         memset(ehdr, 0, sizeof(*ehdr));
 515         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
 516         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
 517         ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
 518         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
 519         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
 520         ehdr->e_type = ET_CORE;
 521         ehdr->e_machine = EM_S390;
 522         ehdr->e_version = EV_CURRENT;
 523         ehdr->e_phoff = sizeof(Elf64_Ehdr);
 524         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
 525         ehdr->e_phentsize = sizeof(Elf64_Phdr);
 526         ehdr->e_phnum = mem_chunk_cnt + 1;
 527         return ehdr + 1;
 528 }
 529 
 530 /*
 531  * Return CPU count for ELF header (new kernel)
 532  */
 533 static int get_cpu_cnt(void)
 534 {
 535         struct save_area *sa;
 536         int cpus = 0;
 537 
 538         list_for_each_entry(sa, &dump_save_areas, list)
 539                 if (sa->prefix != 0)
 540                         cpus++;
 541         return cpus;
 542 }
 543 
 544 /*
 545  * Return memory chunk count for ELF header (new kernel)
 546  */
 547 static int get_mem_chunk_cnt(void)
 548 {
 549         int cnt = 0;
 550         u64 idx;
 551 
 552         for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
 553                            MEMBLOCK_NONE, NULL, NULL, NULL)
 554                 cnt++;
 555         return cnt;
 556 }
 557 
 558 /*
 559  * Initialize ELF loads (new kernel)
 560  */
 561 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
 562 {
 563         phys_addr_t start, end;
 564         u64 idx;
 565 
 566         for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
 567                            MEMBLOCK_NONE, &start, &end, NULL) {
 568                 phdr->p_filesz = end - start;
 569                 phdr->p_type = PT_LOAD;
 570                 phdr->p_offset = start;
 571                 phdr->p_vaddr = start;
 572                 phdr->p_paddr = start;
 573                 phdr->p_memsz = end - start;
 574                 phdr->p_flags = PF_R | PF_W | PF_X;
 575                 phdr->p_align = PAGE_SIZE;
 576                 phdr++;
 577         }
 578 }
 579 
 580 /*
 581  * Initialize notes (new kernel)
 582  */
 583 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
 584 {
 585         struct save_area *sa;
 586         void *ptr_start = ptr;
 587         int cpu;
 588 
 589         ptr = nt_prpsinfo(ptr);
 590 
 591         cpu = 1;
 592         list_for_each_entry(sa, &dump_save_areas, list)
 593                 if (sa->prefix != 0)
 594                         ptr = fill_cpu_elf_notes(ptr, cpu++, sa);
 595         ptr = nt_vmcoreinfo(ptr);
 596         ptr = nt_final(ptr);
 597         memset(phdr, 0, sizeof(*phdr));
 598         phdr->p_type = PT_NOTE;
 599         phdr->p_offset = notes_offset;
 600         phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
 601         phdr->p_memsz = phdr->p_filesz;
 602         return ptr;
 603 }
 604 
 605 static size_t get_elfcorehdr_size(int mem_chunk_cnt)
 606 {
 607         size_t size;
 608 
 609         size = sizeof(Elf64_Ehdr);
 610         /* PT_NOTES */
 611         size += sizeof(Elf64_Phdr);
 612         /* nt_prpsinfo */
 613         size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo));
 614         /* regsets */
 615         size += get_cpu_cnt() * get_cpu_elf_notes_size();
 616         /* nt_vmcoreinfo */
 617         size += nt_vmcoreinfo_size();
 618         /* nt_final */
 619         size += sizeof(Elf64_Nhdr);
 620         /* PT_LOADS */
 621         size += mem_chunk_cnt * sizeof(Elf64_Phdr);
 622 
 623         return size;
 624 }
 625 
 626 /*
 627  * Create ELF core header (new kernel)
 628  */
 629 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
 630 {
 631         Elf64_Phdr *phdr_notes, *phdr_loads;
 632         int mem_chunk_cnt;
 633         void *ptr, *hdr;
 634         u32 alloc_size;
 635         u64 hdr_off;
 636 
 637         /* If we are not in kdump or zfcpdump mode return */
 638         if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
 639                 return 0;
 640         /* If we cannot get HSA size for zfcpdump return error */
 641         if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp.hsa_size)
 642                 return -ENODEV;
 643 
 644         /* For kdump, exclude previous crashkernel memory */
 645         if (OLDMEM_BASE) {
 646                 oldmem_region.base = OLDMEM_BASE;
 647                 oldmem_region.size = OLDMEM_SIZE;
 648                 oldmem_type.total_size = OLDMEM_SIZE;
 649         }
 650 
 651         mem_chunk_cnt = get_mem_chunk_cnt();
 652 
 653         alloc_size = get_elfcorehdr_size(mem_chunk_cnt);
 654 
 655         hdr = kzalloc(alloc_size, GFP_KERNEL);
 656 
 657         /* Without elfcorehdr /proc/vmcore cannot be created. Thus creating
 658          * a dump with this crash kernel will fail. Panic now to allow other
 659          * dump mechanisms to take over.
 660          */
 661         if (!hdr)
 662                 panic("s390 kdump allocating elfcorehdr failed");
 663 
 664         /* Init elf header */
 665         ptr = ehdr_init(hdr, mem_chunk_cnt);
 666         /* Init program headers */
 667         phdr_notes = ptr;
 668         ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
 669         phdr_loads = ptr;
 670         ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
 671         /* Init notes */
 672         hdr_off = PTR_DIFF(ptr, hdr);
 673         ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
 674         /* Init loads */
 675         hdr_off = PTR_DIFF(ptr, hdr);
 676         loads_init(phdr_loads, hdr_off);
 677         *addr = (unsigned long long) hdr;
 678         *size = (unsigned long long) hdr_off;
 679         BUG_ON(elfcorehdr_size > alloc_size);
 680         return 0;
 681 }
 682 
 683 /*
 684  * Free ELF core header (new kernel)
 685  */
 686 void elfcorehdr_free(unsigned long long addr)
 687 {
 688         kfree((void *)(unsigned long)addr);
 689 }
 690 
 691 /*
 692  * Read from ELF header
 693  */
 694 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
 695 {
 696         void *src = (void *)(unsigned long)*ppos;
 697 
 698         memcpy(buf, src, count);
 699         *ppos += count;
 700         return count;
 701 }
 702 
 703 /*
 704  * Read from ELF notes data
 705  */
 706 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
 707 {
 708         void *src = (void *)(unsigned long)*ppos;
 709 
 710         memcpy(buf, src, count);
 711         *ppos += count;
 712         return count;
 713 }