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 <linux/export.h>
11#include <asm/lowcore.h>
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/mm.h>
15#include <linux/gfp.h>
16#include <linux/slab.h>
17#include <linux/memblock.h>
18#include <linux/elf.h>
19#include <linux/uio.h>
20#include <asm/asm-offsets.h>
21#include <asm/os_info.h>
22#include <asm/elf.h>
23#include <asm/ipl.h>
24#include <asm/sclp.h>
25#include <asm/maccess.h>
26#include <asm/fpu.h>
27
28#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
29#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
30#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
31
32static struct memblock_region oldmem_region;
33
34static struct memblock_type oldmem_type = {
35 .cnt = 1,
36 .max = 1,
37 .total_size = 0,
38 .regions = &oldmem_region,
39 .name = "oldmem",
40};
41
42struct save_area {
43 struct list_head list;
44 u64 psw[2];
45 u64 ctrs[16];
46 u64 gprs[16];
47 u32 acrs[16];
48 u64 fprs[16];
49 u32 fpc;
50 u32 prefix;
51 u32 todpreg;
52 u64 timer;
53 u64 todcmp;
54 u64 vxrs_low[16];
55 __vector128 vxrs_high[16];
56};
57
58static LIST_HEAD(dump_save_areas);
59
60/*
61 * Allocate a save area
62 */
63struct save_area * __init save_area_alloc(bool is_boot_cpu)
64{
65 struct save_area *sa;
66
67 sa = memblock_alloc_or_panic(sizeof(*sa), 8);
68
69 if (is_boot_cpu)
70 list_add(new: &sa->list, head: &dump_save_areas);
71 else
72 list_add_tail(new: &sa->list, head: &dump_save_areas);
73 return sa;
74}
75
76/*
77 * Return the address of the save area for the boot CPU
78 */
79struct save_area * __init save_area_boot_cpu(void)
80{
81 return list_first_entry_or_null(&dump_save_areas, struct save_area, list);
82}
83
84/*
85 * Copy CPU registers into the save area
86 */
87void __init save_area_add_regs(struct save_area *sa, void *regs)
88{
89 struct lowcore *lc;
90
91 lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA);
92 memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw));
93 memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs));
94 memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs));
95 memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs));
96 memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs));
97 memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc));
98 memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix));
99 memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg));
100 memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer));
101 memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp));
102}
103
104/*
105 * Copy vector registers into the save area
106 */
107void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
108{
109 int i;
110
111 /* Copy lower halves of vector registers 0-15 */
112 for (i = 0; i < 16; i++)
113 sa->vxrs_low[i] = vxrs[i].low;
114 /* Copy vector registers 16-31 */
115 memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
116}
117
118static size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
119{
120 size_t len, copied, res = 0;
121
122 while (count) {
123 if (!oldmem_data.start && src < sclp.hsa_size) {
124 /* Copy from zfcp/nvme dump HSA area */
125 len = min(count, sclp.hsa_size - src);
126 copied = memcpy_hsa_iter(iter, src, len);
127 } else {
128 /* Check for swapped kdump oldmem areas */
129 if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) {
130 src -= oldmem_data.start;
131 len = min(count, oldmem_data.size - src);
132 } else if (oldmem_data.start && src < oldmem_data.size) {
133 len = min(count, oldmem_data.size - src);
134 src += oldmem_data.start;
135 } else {
136 len = count;
137 }
138 copied = memcpy_real_iter(iter, src, len);
139 }
140 count -= copied;
141 src += copied;
142 res += copied;
143 if (copied < len)
144 break;
145 }
146 return res;
147}
148
149int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
150{
151 struct iov_iter iter;
152 struct kvec kvec;
153
154 kvec.iov_base = dst;
155 kvec.iov_len = count;
156 iov_iter_kvec(i: &iter, ITER_DEST, kvec: &kvec, nr_segs: 1, count);
157 if (copy_oldmem_iter(iter: &iter, src, count) < count)
158 return -EFAULT;
159 return 0;
160}
161
162/*
163 * Copy one page from "oldmem"
164 */
165ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
166 unsigned long offset)
167{
168 unsigned long src;
169
170 src = pfn_to_phys(pfn) + offset;
171 return copy_oldmem_iter(iter, src, count: csize);
172}
173
174/*
175 * Remap "oldmem" for kdump
176 *
177 * For the kdump reserved memory this functions performs a swap operation:
178 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
179 */
180static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
181 unsigned long from, unsigned long pfn,
182 unsigned long size, pgprot_t prot)
183{
184 unsigned long size_old;
185 int rc;
186
187 if (pfn < oldmem_data.size >> PAGE_SHIFT) {
188 size_old = min(size, oldmem_data.size - (pfn << PAGE_SHIFT));
189 rc = remap_pfn_range(vma, from,
190 pfn + (oldmem_data.start >> PAGE_SHIFT),
191 size_old, prot);
192 if (rc || size == size_old)
193 return rc;
194 size -= size_old;
195 from += size_old;
196 pfn += size_old >> PAGE_SHIFT;
197 }
198 return remap_pfn_range(vma, addr: from, pfn, size, pgprot: prot);
199}
200
201/*
202 * Remap "oldmem" for zfcp/nvme dump
203 *
204 * We only map available memory above HSA size. Memory below HSA size
205 * is read on demand using the copy_oldmem_page() function.
206 */
207static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
208 unsigned long from,
209 unsigned long pfn,
210 unsigned long size, pgprot_t prot)
211{
212 unsigned long hsa_end = sclp.hsa_size;
213 unsigned long size_hsa;
214
215 if (pfn < hsa_end >> PAGE_SHIFT) {
216 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
217 if (size == size_hsa)
218 return 0;
219 size -= size_hsa;
220 from += size_hsa;
221 pfn += size_hsa >> PAGE_SHIFT;
222 }
223 return remap_pfn_range(vma, addr: from, pfn, size, pgprot: prot);
224}
225
226/*
227 * Remap "oldmem" for kdump or zfcp/nvme dump
228 */
229int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
230 unsigned long pfn, unsigned long size, pgprot_t prot)
231{
232 if (oldmem_data.start)
233 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
234 else
235 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
236 prot);
237}
238
239/*
240 * Return true only when in a kdump or stand-alone kdump environment.
241 * Note that /proc/vmcore might also be available in "standard zfcp/nvme dump"
242 * environments, where this function returns false; see dump_available().
243 */
244bool is_kdump_kernel(void)
245{
246 return oldmem_data.start;
247}
248EXPORT_SYMBOL_GPL(is_kdump_kernel);
249
250/*
251 * Initialize ELF note
252 */
253static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
254 const char *name)
255{
256 Elf64_Nhdr *note;
257 u64 len;
258
259 note = (Elf64_Nhdr *)buf;
260 note->n_namesz = strlen(name) + 1;
261 note->n_descsz = d_len;
262 note->n_type = type;
263 len = sizeof(Elf64_Nhdr);
264
265 memcpy(buf + len, name, note->n_namesz);
266 len = roundup(len + note->n_namesz, 4);
267
268 memcpy(buf + len, desc, note->n_descsz);
269 len = roundup(len + note->n_descsz, 4);
270
271 return PTR_ADD(buf, len);
272}
273
274#define nt_init(buf, type, desc) \
275 nt_init_name(buf, NT_ ## type, &(desc), sizeof(desc), NN_ ## type)
276
277/*
278 * Calculate the size of ELF note
279 */
280static size_t nt_size_name(int d_len, const char *name)
281{
282 size_t size;
283
284 size = sizeof(Elf64_Nhdr);
285 size += roundup(strlen(name) + 1, 4);
286 size += roundup(d_len, 4);
287
288 return size;
289}
290
291#define nt_size(type, desc) nt_size_name(sizeof(desc), NN_ ## type)
292
293/*
294 * Fill ELF notes for one CPU with save area registers
295 */
296static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
297{
298 struct elf_prstatus nt_prstatus;
299 elf_fpregset_t nt_fpregset;
300
301 /* Prepare prstatus note */
302 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
303 memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
304 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
305 memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
306 nt_prstatus.common.pr_pid = cpu;
307 /* Prepare fpregset (floating point) note */
308 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
309 memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
310 memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
311 /* Create ELF notes for the CPU */
312 ptr = nt_init(ptr, PRSTATUS, nt_prstatus);
313 ptr = nt_init(ptr, PRFPREG, nt_fpregset);
314 ptr = nt_init(ptr, S390_TIMER, sa->timer);
315 ptr = nt_init(ptr, S390_TODCMP, sa->todcmp);
316 ptr = nt_init(ptr, S390_TODPREG, sa->todpreg);
317 ptr = nt_init(ptr, S390_CTRS, sa->ctrs);
318 ptr = nt_init(ptr, S390_PREFIX, sa->prefix);
319 if (cpu_has_vx()) {
320 ptr = nt_init(ptr, S390_VXRS_HIGH, sa->vxrs_high);
321 ptr = nt_init(ptr, S390_VXRS_LOW, sa->vxrs_low);
322 }
323 return ptr;
324}
325
326/*
327 * Calculate size of ELF notes per cpu
328 */
329static size_t get_cpu_elf_notes_size(void)
330{
331 struct save_area *sa = NULL;
332 size_t size;
333
334 size = nt_size(PRSTATUS, struct elf_prstatus);
335 size += nt_size(PRFPREG, elf_fpregset_t);
336 size += nt_size(S390_TIMER, sa->timer);
337 size += nt_size(S390_TODCMP, sa->todcmp);
338 size += nt_size(S390_TODPREG, sa->todpreg);
339 size += nt_size(S390_CTRS, sa->ctrs);
340 size += nt_size(S390_PREFIX, sa->prefix);
341 if (cpu_has_vx()) {
342 size += nt_size(S390_VXRS_HIGH, sa->vxrs_high);
343 size += nt_size(S390_VXRS_LOW, sa->vxrs_low);
344 }
345
346 return size;
347}
348
349/*
350 * Initialize prpsinfo note (new kernel)
351 */
352static void *nt_prpsinfo(void *ptr)
353{
354 struct elf_prpsinfo prpsinfo;
355
356 memset(&prpsinfo, 0, sizeof(prpsinfo));
357 prpsinfo.pr_sname = 'R';
358 strscpy(prpsinfo.pr_fname, "vmlinux");
359 return nt_init(ptr, PRPSINFO, prpsinfo);
360}
361
362/*
363 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
364 */
365static void *get_vmcoreinfo_old(unsigned long *size)
366{
367 char nt_name[11], *vmcoreinfo;
368 unsigned long addr;
369 Elf64_Nhdr note;
370
371 if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr)))
372 return NULL;
373 memset(nt_name, 0, sizeof(nt_name));
374 if (copy_oldmem_kernel(dst: &note, src: addr, count: sizeof(note)))
375 return NULL;
376 if (copy_oldmem_kernel(dst: nt_name, src: addr + sizeof(note),
377 count: sizeof(nt_name) - 1))
378 return NULL;
379 if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0)
380 return NULL;
381 vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL);
382 if (!vmcoreinfo)
383 return NULL;
384 if (copy_oldmem_kernel(dst: vmcoreinfo, src: addr + 24, count: note.n_descsz)) {
385 kfree(objp: vmcoreinfo);
386 return NULL;
387 }
388 *size = note.n_descsz;
389 return vmcoreinfo;
390}
391
392/*
393 * Initialize vmcoreinfo note (new kernel)
394 */
395static void *nt_vmcoreinfo(void *ptr)
396{
397 const char *name = VMCOREINFO_NOTE_NAME;
398 unsigned long size;
399 void *vmcoreinfo;
400
401 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
402 if (vmcoreinfo)
403 return nt_init_name(buf: ptr, type: 0, desc: vmcoreinfo, d_len: size, name);
404
405 vmcoreinfo = get_vmcoreinfo_old(size: &size);
406 if (!vmcoreinfo)
407 return ptr;
408 ptr = nt_init_name(buf: ptr, type: 0, desc: vmcoreinfo, d_len: size, name);
409 kfree(objp: vmcoreinfo);
410 return ptr;
411}
412
413static size_t nt_vmcoreinfo_size(void)
414{
415 const char *name = VMCOREINFO_NOTE_NAME;
416 unsigned long size;
417 void *vmcoreinfo;
418
419 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
420 if (vmcoreinfo)
421 return nt_size_name(d_len: size, name);
422
423 vmcoreinfo = get_vmcoreinfo_old(size: &size);
424 if (!vmcoreinfo)
425 return 0;
426
427 kfree(objp: vmcoreinfo);
428 return nt_size_name(d_len: size, name);
429}
430
431/*
432 * Initialize final note (needed for /proc/vmcore code)
433 */
434static void *nt_final(void *ptr)
435{
436 Elf64_Nhdr *note;
437
438 note = (Elf64_Nhdr *) ptr;
439 note->n_namesz = 0;
440 note->n_descsz = 0;
441 note->n_type = 0;
442 return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
443}
444
445/*
446 * Initialize ELF header (new kernel)
447 */
448static void *ehdr_init(Elf64_Ehdr *ehdr, int phdr_count)
449{
450 memset(ehdr, 0, sizeof(*ehdr));
451 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
452 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
453 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
454 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
455 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
456 ehdr->e_type = ET_CORE;
457 ehdr->e_machine = EM_S390;
458 ehdr->e_version = EV_CURRENT;
459 ehdr->e_phoff = sizeof(Elf64_Ehdr);
460 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
461 ehdr->e_phentsize = sizeof(Elf64_Phdr);
462 /* Number of PT_LOAD program headers plus PT_NOTE program header */
463 ehdr->e_phnum = phdr_count + 1;
464 return ehdr + 1;
465}
466
467/*
468 * Return CPU count for ELF header (new kernel)
469 */
470static int get_cpu_cnt(void)
471{
472 struct save_area *sa;
473 int cpus = 0;
474
475 list_for_each_entry(sa, &dump_save_areas, list)
476 if (sa->prefix != 0)
477 cpus++;
478 return cpus;
479}
480
481/*
482 * Return memory chunk count for ELF header (new kernel)
483 */
484static int get_mem_chunk_cnt(void)
485{
486 int cnt = 0;
487 u64 idx;
488
489 for_each_physmem_range(idx, &oldmem_type, NULL, NULL)
490 cnt++;
491 return cnt;
492}
493
494static void fill_ptload(Elf64_Phdr *phdr, unsigned long paddr,
495 unsigned long vaddr, unsigned long size)
496{
497 phdr->p_type = PT_LOAD;
498 phdr->p_vaddr = vaddr;
499 phdr->p_offset = paddr;
500 phdr->p_paddr = paddr;
501 phdr->p_filesz = size;
502 phdr->p_memsz = size;
503 phdr->p_flags = PF_R | PF_W | PF_X;
504 phdr->p_align = PAGE_SIZE;
505}
506
507/*
508 * Initialize ELF loads (new kernel)
509 */
510static void loads_init(Elf64_Phdr *phdr, bool os_info_has_vm)
511{
512 unsigned long old_identity_base = 0;
513 phys_addr_t start, end;
514 u64 idx;
515
516 if (os_info_has_vm)
517 old_identity_base = os_info_old_value(OS_INFO_IDENTITY_BASE);
518 for_each_physmem_range(idx, &oldmem_type, &start, &end) {
519 fill_ptload(phdr, paddr: start, vaddr: old_identity_base + start,
520 size: end - start);
521 phdr++;
522 }
523}
524
525static bool os_info_has_vm(void)
526{
527 return os_info_old_value(OS_INFO_KASLR_OFFSET);
528}
529
530#ifdef CONFIG_PROC_VMCORE_DEVICE_RAM
531/*
532 * Fill PT_LOAD for a physical memory range owned by a device and detected by
533 * its device driver.
534 */
535void elfcorehdr_fill_device_ram_ptload_elf64(Elf64_Phdr *phdr,
536 unsigned long long paddr, unsigned long long size)
537{
538 unsigned long old_identity_base = 0;
539
540 if (os_info_has_vm())
541 old_identity_base = os_info_old_value(OS_INFO_IDENTITY_BASE);
542 fill_ptload(phdr, paddr, old_identity_base + paddr, size);
543}
544#endif
545
546/*
547 * Prepare PT_LOAD type program header for kernel image region
548 */
549static void text_init(Elf64_Phdr *phdr)
550{
551 unsigned long start_phys = os_info_old_value(OS_INFO_IMAGE_PHYS);
552 unsigned long start = os_info_old_value(OS_INFO_IMAGE_START);
553 unsigned long end = os_info_old_value(OS_INFO_IMAGE_END);
554
555 phdr->p_type = PT_LOAD;
556 phdr->p_vaddr = start;
557 phdr->p_filesz = end - start;
558 phdr->p_memsz = end - start;
559 phdr->p_offset = start_phys;
560 phdr->p_paddr = start_phys;
561 phdr->p_flags = PF_R | PF_W | PF_X;
562 phdr->p_align = PAGE_SIZE;
563}
564
565/*
566 * Initialize notes (new kernel)
567 */
568static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
569{
570 struct save_area *sa;
571 void *ptr_start = ptr;
572 int cpu;
573
574 ptr = nt_prpsinfo(ptr);
575
576 cpu = 1;
577 list_for_each_entry(sa, &dump_save_areas, list)
578 if (sa->prefix != 0)
579 ptr = fill_cpu_elf_notes(ptr, cpu: cpu++, sa);
580 ptr = nt_vmcoreinfo(ptr);
581 ptr = nt_final(ptr);
582 memset(phdr, 0, sizeof(*phdr));
583 phdr->p_type = PT_NOTE;
584 phdr->p_offset = notes_offset;
585 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
586 phdr->p_memsz = phdr->p_filesz;
587 return ptr;
588}
589
590static size_t get_elfcorehdr_size(int phdr_count)
591{
592 size_t size;
593
594 size = sizeof(Elf64_Ehdr);
595 /* PT_NOTES */
596 size += sizeof(Elf64_Phdr);
597 /* nt_prpsinfo */
598 size += nt_size(PRPSINFO, struct elf_prpsinfo);
599 /* regsets */
600 size += get_cpu_cnt() * get_cpu_elf_notes_size();
601 /* nt_vmcoreinfo */
602 size += nt_vmcoreinfo_size();
603 /* nt_final */
604 size += sizeof(Elf64_Nhdr);
605 /* PT_LOADS */
606 size += phdr_count * sizeof(Elf64_Phdr);
607
608 return size;
609}
610
611/*
612 * Create ELF core header (new kernel)
613 */
614int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
615{
616 Elf64_Phdr *phdr_notes, *phdr_loads, *phdr_text;
617 int mem_chunk_cnt, phdr_text_cnt;
618 size_t alloc_size;
619 void *ptr, *hdr;
620 u64 hdr_off;
621
622 /* If we are not in kdump or zfcp/nvme dump mode return */
623 if (!oldmem_data.start && !is_ipl_type_dump())
624 return 0;
625 /* If we cannot get HSA size for zfcp/nvme dump return error */
626 if (is_ipl_type_dump() && !sclp.hsa_size)
627 return -ENODEV;
628
629 /* For kdump, exclude previous crashkernel memory */
630 if (oldmem_data.start) {
631 oldmem_region.base = oldmem_data.start;
632 oldmem_region.size = oldmem_data.size;
633 oldmem_type.total_size = oldmem_data.size;
634 }
635
636 mem_chunk_cnt = get_mem_chunk_cnt();
637 phdr_text_cnt = os_info_has_vm() ? 1 : 0;
638
639 alloc_size = get_elfcorehdr_size(phdr_count: mem_chunk_cnt + phdr_text_cnt);
640
641 hdr = kzalloc(alloc_size, GFP_KERNEL);
642
643 /*
644 * Without elfcorehdr /proc/vmcore cannot be created. Thus creating
645 * a dump with this crash kernel will fail. Panic now to allow other
646 * dump mechanisms to take over.
647 */
648 if (!hdr)
649 panic(fmt: "s390 kdump allocating elfcorehdr failed");
650
651 /* Init elf header */
652 phdr_notes = ehdr_init(ehdr: hdr, phdr_count: mem_chunk_cnt + phdr_text_cnt);
653 /* Init program headers */
654 if (phdr_text_cnt) {
655 phdr_text = phdr_notes + 1;
656 phdr_loads = phdr_text + 1;
657 } else {
658 phdr_loads = phdr_notes + 1;
659 }
660 ptr = PTR_ADD(phdr_loads, sizeof(Elf64_Phdr) * mem_chunk_cnt);
661 /* Init notes */
662 hdr_off = PTR_DIFF(ptr, hdr);
663 ptr = notes_init(phdr: phdr_notes, ptr, notes_offset: ((unsigned long) hdr) + hdr_off);
664 /* Init kernel text program header */
665 if (phdr_text_cnt)
666 text_init(phdr: phdr_text);
667 /* Init loads */
668 loads_init(phdr: phdr_loads, os_info_has_vm: phdr_text_cnt);
669 /* Finalize program headers */
670 hdr_off = PTR_DIFF(ptr, hdr);
671 *addr = (unsigned long long) hdr;
672 *size = (unsigned long long) hdr_off;
673 BUG_ON(elfcorehdr_size > alloc_size);
674 return 0;
675}
676
677/*
678 * Free ELF core header (new kernel)
679 */
680void elfcorehdr_free(unsigned long long addr)
681{
682 kfree(objp: (void *)(unsigned long)addr);
683}
684
685/*
686 * Read from ELF header
687 */
688ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
689{
690 void *src = (void *)(unsigned long)*ppos;
691
692 memcpy(buf, src, count);
693 *ppos += count;
694 return count;
695}
696
697/*
698 * Read from ELF notes data
699 */
700ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
701{
702 void *src = (void *)(unsigned long)*ppos;
703
704 memcpy(buf, src, count);
705 *ppos += count;
706 return count;
707}
708

source code of linux/arch/s390/kernel/crash_dump.c