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TOMOYO Linux Cross Reference
Linux/arch/s390/kernel/crash_dump.c

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

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