arch/s390/kernel/crash_dump.c

   1 /*
   2  * S390 kdump implementation
   3  *
   4  * Copyright IBM Corp. 2011
   5  * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
   6  */
   7
   8 #include <linux/crash_dump.h>
   9 #include <asm/lowcore.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/gfp.h>
  13 #include <linux/slab.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/elf.h>
  16 #include <linux/memblock.h>
  17 #include <asm/os_info.h>
  18 #include <asm/elf.h>
  19 #include <asm/ipl.h>
  20 #include <asm/sclp.h>
  21
  22 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
  23 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
  24 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
  25
  26 static struct memblock_region oldmem_region;
  27
  28 static struct memblock_type oldmem_type = {
  29         .cnt = 1,
  30         .max = 1,
  31         .total_size = 0,
  32         .regions = &oldmem_region,
  33 };
  34
  35 struct dump_save_areas dump_save_areas;
  36
  37 /*
  38  * Return physical address for virtual address
  39  */
  40 static inline void *load_real_addr(void *addr)
  41 {
  42         unsigned long real_addr;
  43
  44         asm volatile(
  45                    "    lra     %0,0(%1)\n"
  46                    "    jz      0f\n"
  47                    "    la      %0,0\n"
  48                    "0:"
  49                    : "=a" (real_addr) : "a" (addr) : "cc");
  50         return (void *)real_addr;
  51 }
  52
  53 /*
  54  * Copy real to virtual or real memory
  55  */
  56 static int copy_from_realmem(void *dest, void *src, size_t count)
  57 {
  58         unsigned long size;
  59
  60         if (!count)
  61                 return 0;
  62         if (!is_vmalloc_or_module_addr(dest))
  63                 return memcpy_real(dest, src, count);
  64         do {
  65                 size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));
  66                 if (memcpy_real(load_real_addr(dest), src, size))
  67                         return -EFAULT;
  68                 count -= size;
  69                 dest += size;
  70                 src += size;
  71         } while (count);
  72         return 0;
  73 }
  74
  75 /*
  76  * Pointer to ELF header in new kernel
  77  */
  78 static void *elfcorehdr_newmem;
  79
  80 /*
  81  * Copy one page from zfcpdump "oldmem"
  82  *
  83  * For pages below HSA size memory from the HSA is copied. Otherwise
  84  * real memory copy is used.
  85  */
  86 static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
  87                                          unsigned long src, int userbuf)
  88 {
  89         int rc;
  90
  91         if (src < sclp.hsa_size) {
  92                 rc = memcpy_hsa(buf, src, csize, userbuf);
  93         } else {
  94                 if (userbuf)
  95                         rc = copy_to_user_real((void __force __user *) buf,
  96                                                (void *) src, csize);
  97                 else
  98                         rc = memcpy_real(buf, (void *) src, csize);
  99         }
 100         return rc ? rc : csize;
 101 }
 102
 103 /*
 104  * Copy one page from kdump "oldmem"
 105  *
 106  * For the kdump reserved memory this functions performs a swap operation:
 107  *  - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
 108  *  - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
 109  */
 110 static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
 111                                       unsigned long src, int userbuf)
 112
 113 {
 114         int rc;
 115
 116         if (src < OLDMEM_SIZE)
 117                 src += OLDMEM_BASE;
 118         else if (src > OLDMEM_BASE &&
 119                  src < OLDMEM_BASE + OLDMEM_SIZE)
 120                 src -= OLDMEM_BASE;
 121         if (userbuf)
 122                 rc = copy_to_user_real((void __force __user *) buf,
 123                                        (void *) src, csize);
 124         else
 125                 rc = copy_from_realmem(buf, (void *) src, csize);
 126         return (rc == 0) ? rc : csize;
 127 }
 128
 129 /*
 130  * Copy one page from "oldmem"
 131  */
 132 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 133                          unsigned long offset, int userbuf)
 134 {
 135         unsigned long src;
 136
 137         if (!csize)
 138                 return 0;
 139         src = (pfn << PAGE_SHIFT) + offset;
 140         if (OLDMEM_BASE)
 141                 return copy_oldmem_page_kdump(buf, csize, src, userbuf);
 142         else
 143                 return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
 144 }
 145
 146 /*
 147  * Remap "oldmem" for kdump
 148  *
 149  * For the kdump reserved memory this functions performs a swap operation:
 150  * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
 151  */
 152 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
 153                                         unsigned long from, unsigned long pfn,
 154                                         unsigned long size, pgprot_t prot)
 155 {
 156         unsigned long size_old;
 157         int rc;
 158
 159         if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
 160                 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
 161                 rc = remap_pfn_range(vma, from,
 162                                      pfn + (OLDMEM_BASE >> PAGE_SHIFT),
 163                                      size_old, prot);
 164                 if (rc || size == size_old)
 165                         return rc;
 166                 size -= size_old;
 167                 from += size_old;
 168                 pfn += size_old >> PAGE_SHIFT;
 169         }
 170         return remap_pfn_range(vma, from, pfn, size, prot);
 171 }
 172
 173 /*
 174  * Remap "oldmem" for zfcpdump
 175  *
 176  * We only map available memory above HSA size. Memory below HSA size
 177  * is read on demand using the copy_oldmem_page() function.
 178  */
 179 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
 180                                            unsigned long from,
 181                                            unsigned long pfn,
 182                                            unsigned long size, pgprot_t prot)
 183 {
 184         unsigned long hsa_end = sclp.hsa_size;
 185         unsigned long size_hsa;
 186
 187         if (pfn < hsa_end >> PAGE_SHIFT) {
 188                 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
 189                 if (size == size_hsa)
 190                         return 0;
 191                 size -= size_hsa;
 192                 from += size_hsa;
 193                 pfn += size_hsa >> PAGE_SHIFT;
 194         }
 195         return remap_pfn_range(vma, from, pfn, size, prot);
 196 }
 197
 198 /*
 199  * Remap "oldmem" for kdump or zfcpdump
 200  */
 201 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
 202                            unsigned long pfn, unsigned long size, pgprot_t prot)
 203 {
 204         if (OLDMEM_BASE)
 205                 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
 206         else
 207                 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
 208                                                        prot);
 209 }
 210
 211 /*
 212  * Copy memory from old kernel
 213  */
 214 int copy_from_oldmem(void *dest, void *src, size_t count)
 215 {
 216         unsigned long copied = 0;
 217         int rc;
 218
 219         if (OLDMEM_BASE) {
 220                 if ((unsigned long) src < OLDMEM_SIZE) {
 221                         copied = min(count, OLDMEM_SIZE - (unsigned long) src);
 222                         rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied);
 223                         if (rc)
 224                                 return rc;
 225                 }
 226         } else {
 227                 unsigned long hsa_end = sclp.hsa_size;
 228                 if ((unsigned long) src < hsa_end) {
 229                         copied = min(count, hsa_end - (unsigned long) src);
 230                         rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
 231                         if (rc)
 232                                 return rc;
 233                 }
 234         }
 235         return copy_from_realmem(dest + copied, src + copied, count - copied);
 236 }
 237
 238 /*
 239  * Alloc memory and panic in case of ENOMEM
 240  */
 241 static void *kzalloc_panic(int len)
 242 {
 243         void *rc;
 244
 245         rc = kzalloc(len, GFP_KERNEL);
 246         if (!rc)
 247                 panic("s390 kdump kzalloc (%d) failed", len);
 248         return rc;
 249 }
 250
 251 /*
 252  * Initialize ELF note
 253  */
 254 static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len,
 255                      const char *name)
 256 {
 257         Elf64_Nhdr *note;
 258         u64 len;
 259
 260         note = (Elf64_Nhdr *)buf;
 261         note->n_namesz = strlen(name) + 1;
 262         note->n_descsz = d_len;
 263         note->n_type = type;
 264         len = sizeof(Elf64_Nhdr);
 265
 266         memcpy(buf + len, name, note->n_namesz);
 267         len = roundup(len + note->n_namesz, 4);
 268
 269         memcpy(buf + len, desc, note->n_descsz);
 270         len = roundup(len + note->n_descsz, 4);
 271
 272         return PTR_ADD(buf, len);
 273 }
 274
 275 /*
 276  * Initialize prstatus note
 277  */
 278 static void *nt_prstatus(void *ptr, struct save_area *sa)
 279 {
 280         struct elf_prstatus nt_prstatus;
 281         static int cpu_nr = 1;
 282
 283         memset(&nt_prstatus, 0, sizeof(nt_prstatus));
 284         memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
 285         memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
 286         memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
 287         nt_prstatus.pr_pid = cpu_nr;
 288         cpu_nr++;
 289
 290         return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
 291                          "CORE");
 292 }
 293
 294 /*
 295  * Initialize fpregset (floating point) note
 296  */
 297 static void *nt_fpregset(void *ptr, struct save_area *sa)
 298 {
 299         elf_fpregset_t nt_fpregset;
 300
 301         memset(&nt_fpregset, 0, sizeof(nt_fpregset));
 302         memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
 303         memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
 304
 305         return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
 306                        "CORE");
 307 }
 308
 309 /*
 310  * Initialize timer note
 311  */
 312 static void *nt_s390_timer(void *ptr, struct save_area *sa)
 313 {
 314         return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
 315                          KEXEC_CORE_NOTE_NAME);
 316 }
 317
 318 /*
 319  * Initialize TOD clock comparator note
 320  */
 321 static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
 322 {
 323         return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
 324                        sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
 325 }
 326
 327 /*
 328  * Initialize TOD programmable register note
 329  */
 330 static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
 331 {
 332         return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
 333                        sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
 334 }
 335
 336 /*
 337  * Initialize control register note
 338  */
 339 static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
 340 {
 341         return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
 342                        sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
 343 }
 344
 345 /*
 346  * Initialize prefix register note
 347  */
 348 static void *nt_s390_prefix(void *ptr, struct save_area *sa)
 349 {
 350         return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
 351                          sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
 352 }
 353
 354 /*
 355  * Initialize vxrs high note (full 128 bit VX registers 16-31)
 356  */
 357 static void *nt_s390_vx_high(void *ptr, __vector128 *vx_regs)
 358 {
 359         return nt_init(ptr, NT_S390_VXRS_HIGH, &vx_regs[16],
 360                        16 * sizeof(__vector128), KEXEC_CORE_NOTE_NAME);
 361 }
 362
 363 /*
 364  * Initialize vxrs low note (lower halves of VX registers 0-15)
 365  */
 366 static void *nt_s390_vx_low(void *ptr, __vector128 *vx_regs)
 367 {
 368         Elf64_Nhdr *note;
 369         u64 len;
 370         int i;
 371
 372         note = (Elf64_Nhdr *)ptr;
 373         note->n_namesz = strlen(KEXEC_CORE_NOTE_NAME) + 1;
 374         note->n_descsz = 16 * 8;
 375         note->n_type = NT_S390_VXRS_LOW;
 376         len = sizeof(Elf64_Nhdr);
 377
 378         memcpy(ptr + len, KEXEC_CORE_NOTE_NAME, note->n_namesz);
 379         len = roundup(len + note->n_namesz, 4);
 380
 381         ptr += len;
 382         /* Copy lower halves of SIMD registers 0-15 */
 383         for (i = 0; i < 16; i++) {
 384                 memcpy(ptr, &vx_regs[i].u[2], 8);
 385                 ptr += 8;
 386         }
 387         return ptr;
 388 }
 389
 390 /*
 391  * Fill ELF notes for one CPU with save area registers
 392  */
 393 void *fill_cpu_elf_notes(void *ptr, struct save_area *sa, __vector128 *vx_regs)
 394 {
 395         ptr = nt_prstatus(ptr, sa);
 396         ptr = nt_fpregset(ptr, sa);
 397         ptr = nt_s390_timer(ptr, sa);
 398         ptr = nt_s390_tod_cmp(ptr, sa);
 399         ptr = nt_s390_tod_preg(ptr, sa);
 400         ptr = nt_s390_ctrs(ptr, sa);
 401         ptr = nt_s390_prefix(ptr, sa);
 402         if (MACHINE_HAS_VX && vx_regs) {
 403                 ptr = nt_s390_vx_low(ptr, vx_regs);
 404                 ptr = nt_s390_vx_high(ptr, vx_regs);
 405         }
 406         return ptr;
 407 }
 408
 409 /*
 410  * Initialize prpsinfo note (new kernel)
 411  */
 412 static void *nt_prpsinfo(void *ptr)
 413 {
 414         struct elf_prpsinfo prpsinfo;
 415
 416         memset(&prpsinfo, 0, sizeof(prpsinfo));
 417         prpsinfo.pr_sname = 'R';
 418         strcpy(prpsinfo.pr_fname, "vmlinux");
 419         return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
 420                        KEXEC_CORE_NOTE_NAME);
 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_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
 433                 return NULL;
 434         memset(nt_name, 0, sizeof(nt_name));
 435         if (copy_from_oldmem(&note, addr, sizeof(note)))
 436                 return NULL;
 437         if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
 438                 return NULL;
 439         if (strcmp(nt_name, "VMCOREINFO") != 0)
 440                 return NULL;
 441         vmcoreinfo = kzalloc_panic(note.n_descsz);
 442         if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
 443                 return NULL;
 444         *size = note.n_descsz;
 445         return vmcoreinfo;
 446 }
 447
 448 /*
 449  * Initialize vmcoreinfo note (new kernel)
 450  */
 451 static void *nt_vmcoreinfo(void *ptr)
 452 {
 453         unsigned long size;
 454         void *vmcoreinfo;
 455
 456         vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
 457         if (!vmcoreinfo)
 458                 vmcoreinfo = get_vmcoreinfo_old(&size);
 459         if (!vmcoreinfo)
 460                 return ptr;
 461         return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
 462 }
 463
 464 /*
 465  * Initialize ELF header (new kernel)
 466  */
 467 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
 468 {
 469         memset(ehdr, 0, sizeof(*ehdr));
 470         memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
 471         ehdr->e_ident[EI_CLASS] = ELFCLASS64;
 472         ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
 473         ehdr->e_ident[EI_VERSION] = EV_CURRENT;
 474         memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
 475         ehdr->e_type = ET_CORE;
 476         ehdr->e_machine = EM_S390;
 477         ehdr->e_version = EV_CURRENT;
 478         ehdr->e_phoff = sizeof(Elf64_Ehdr);
 479         ehdr->e_ehsize = sizeof(Elf64_Ehdr);
 480         ehdr->e_phentsize = sizeof(Elf64_Phdr);
 481         ehdr->e_phnum = mem_chunk_cnt + 1;
 482         return ehdr + 1;
 483 }
 484
 485 /*
 486  * Return CPU count for ELF header (new kernel)
 487  */
 488 static int get_cpu_cnt(void)
 489 {
 490         int i, cpus = 0;
 491
 492         for (i = 0; i < dump_save_areas.count; i++) {
 493                 if (dump_save_areas.areas[i]->sa.pref_reg == 0)
 494                         continue;
 495                 cpus++;
 496         }
 497         return cpus;
 498 }
 499
 500 /*
 501  * Return memory chunk count for ELF header (new kernel)
 502  */
 503 static int get_mem_chunk_cnt(void)
 504 {
 505         int cnt = 0;
 506         u64 idx;
 507
 508         for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
 509                            MEMBLOCK_NONE, NULL, NULL, NULL)
 510                 cnt++;
 511         return cnt;
 512 }
 513
 514 /*
 515  * Initialize ELF loads (new kernel)
 516  */
 517 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
 518 {
 519         phys_addr_t start, end;
 520         u64 idx;
 521
 522         for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
 523                            MEMBLOCK_NONE, &start, &end, NULL) {
 524                 phdr->p_filesz = end - start;
 525                 phdr->p_type = PT_LOAD;
 526                 phdr->p_offset = start;
 527                 phdr->p_vaddr = start;
 528                 phdr->p_paddr = start;
 529                 phdr->p_memsz = end - start;
 530                 phdr->p_flags = PF_R | PF_W | PF_X;
 531                 phdr->p_align = PAGE_SIZE;
 532                 phdr++;
 533         }
 534 }
 535
 536 /*
 537  * Initialize notes (new kernel)
 538  */
 539 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
 540 {
 541         struct save_area_ext *sa_ext;
 542         void *ptr_start = ptr;
 543         int i;
 544
 545         ptr = nt_prpsinfo(ptr);
 546
 547         for (i = 0; i < dump_save_areas.count; i++) {
 548                 sa_ext = dump_save_areas.areas[i];
 549                 if (sa_ext->sa.pref_reg == 0)
 550                         continue;
 551                 ptr = fill_cpu_elf_notes(ptr, &sa_ext->sa, sa_ext->vx_regs);
 552         }
 553         ptr = nt_vmcoreinfo(ptr);
 554         memset(phdr, 0, sizeof(*phdr));
 555         phdr->p_type = PT_NOTE;
 556         phdr->p_offset = notes_offset;
 557         phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
 558         phdr->p_memsz = phdr->p_filesz;
 559         return ptr;
 560 }
 561
 562 /*
 563  * Create ELF core header (new kernel)
 564  */
 565 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
 566 {
 567         Elf64_Phdr *phdr_notes, *phdr_loads;
 568         int mem_chunk_cnt;
 569         void *ptr, *hdr;
 570         u32 alloc_size;
 571         u64 hdr_off;
 572
 573         /* If we are not in kdump or zfcpdump mode return */
 574         if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
 575                 return 0;
 576         /* If elfcorehdr= has been passed via cmdline, we use that one */
 577         if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
 578                 return 0;
 579         /* If we cannot get HSA size for zfcpdump return error */
 580         if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp.hsa_size)
 581                 return -ENODEV;
 582
 583         /* For kdump, exclude previous crashkernel memory */
 584         if (OLDMEM_BASE) {
 585                 oldmem_region.base = OLDMEM_BASE;
 586                 oldmem_region.size = OLDMEM_SIZE;
 587                 oldmem_type.total_size = OLDMEM_SIZE;
 588         }
 589
 590         mem_chunk_cnt = get_mem_chunk_cnt();
 591
 592         alloc_size = 0x1000 + get_cpu_cnt() * 0x4a0 +
 593                 mem_chunk_cnt * sizeof(Elf64_Phdr);
 594         hdr = kzalloc_panic(alloc_size);
 595         /* Init elf header */
 596         ptr = ehdr_init(hdr, mem_chunk_cnt);
 597         /* Init program headers */
 598         phdr_notes = ptr;
 599         ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
 600         phdr_loads = ptr;
 601         ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
 602         /* Init notes */
 603         hdr_off = PTR_DIFF(ptr, hdr);
 604         ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
 605         /* Init loads */
 606         hdr_off = PTR_DIFF(ptr, hdr);
 607         loads_init(phdr_loads, hdr_off);
 608         *addr = (unsigned long long) hdr;
 609         elfcorehdr_newmem = hdr;
 610         *size = (unsigned long long) hdr_off;
 611         BUG_ON(elfcorehdr_size > alloc_size);
 612         return 0;
 613 }
 614
 615 /*
 616  * Free ELF core header (new kernel)
 617  */
 618 void elfcorehdr_free(unsigned long long addr)
 619 {
 620         if (!elfcorehdr_newmem)
 621                 return;
 622         kfree((void *)(unsigned long)addr);
 623 }
 624
 625 /*
 626  * Read from ELF header
 627  */
 628 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
 629 {
 630         void *src = (void *)(unsigned long)*ppos;
 631
 632         src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
 633         memcpy(buf, src, count);
 634         *ppos += count;
 635         return count;
 636 }
 637
 638 /*
 639  * Read from ELF notes data
 640  */
 641 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
 642 {
 643         void *src = (void *)(unsigned long)*ppos;
 644         int rc;
 645
 646         if (elfcorehdr_newmem) {
 647                 memcpy(buf, src, count);
 648         } else {
 649                 rc = copy_from_oldmem(buf, src, count);
 650                 if (rc)
 651                         return rc;
 652         }
 653         *ppos += count;
 654         return count;
 655 }