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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
31static struct memblock_region oldmem_region;
32
33static struct memblock_type oldmem_type = {
34 .cnt = 1,
35 .max = 1,
36 .total_size = 0,
37 .regions = &oldmem_region,
38 .name = "oldmem",
39};
40
41struct 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
57static LIST_HEAD(dump_save_areas);
58
59/*
60 * Allocate a save area
61 */
62struct 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 */
80struct 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 */
88void __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 */
108void __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
119static 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
150int 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 */
166ssize_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 */
181static 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 */
208static 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 */
230int 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/*
241 * Return true only when in a kdump or stand-alone kdump environment.
242 * Note that /proc/vmcore might also be available in "standard zfcp/nvme dump"
243 * environments, where this function returns false; see dump_available().
244 */
245bool is_kdump_kernel(void)
246{
247 return oldmem_data.start;
248}
249EXPORT_SYMBOL_GPL(is_kdump_kernel);
250
251static const char *nt_name(Elf64_Word type)
252{
253 const char *name = "LINUX";
254
255 if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG)
256 name = KEXEC_CORE_NOTE_NAME;
257 return name;
258}
259
260/*
261 * Initialize ELF note
262 */
263static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
264 const char *name)
265{
266 Elf64_Nhdr *note;
267 u64 len;
268
269 note = (Elf64_Nhdr *)buf;
270 note->n_namesz = strlen(name) + 1;
271 note->n_descsz = d_len;
272 note->n_type = type;
273 len = sizeof(Elf64_Nhdr);
274
275 memcpy(buf + len, name, note->n_namesz);
276 len = roundup(len + note->n_namesz, 4);
277
278 memcpy(buf + len, desc, note->n_descsz);
279 len = roundup(len + note->n_descsz, 4);
280
281 return PTR_ADD(buf, len);
282}
283
284static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
285{
286 return nt_init_name(buf, type, desc, d_len, nt_name(type));
287}
288
289/*
290 * Calculate the size of ELF note
291 */
292static size_t nt_size_name(int d_len, const char *name)
293{
294 size_t size;
295
296 size = sizeof(Elf64_Nhdr);
297 size += roundup(strlen(name) + 1, 4);
298 size += roundup(d_len, 4);
299
300 return size;
301}
302
303static inline size_t nt_size(Elf64_Word type, int d_len)
304{
305 return nt_size_name(d_len, nt_name(type));
306}
307
308/*
309 * Fill ELF notes for one CPU with save area registers
310 */
311static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
312{
313 struct elf_prstatus nt_prstatus;
314 elf_fpregset_t nt_fpregset;
315
316 /* Prepare prstatus note */
317 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
318 memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
319 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
320 memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
321 nt_prstatus.common.pr_pid = cpu;
322 /* Prepare fpregset (floating point) note */
323 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
324 memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
325 memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
326 /* Create ELF notes for the CPU */
327 ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
328 ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
329 ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
330 ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
331 ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
332 ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
333 ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
334 if (cpu_has_vx()) {
335 ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
336 &sa->vxrs_high, sizeof(sa->vxrs_high));
337 ptr = nt_init(ptr, NT_S390_VXRS_LOW,
338 &sa->vxrs_low, sizeof(sa->vxrs_low));
339 }
340 return ptr;
341}
342
343/*
344 * Calculate size of ELF notes per cpu
345 */
346static size_t get_cpu_elf_notes_size(void)
347{
348 struct save_area *sa = NULL;
349 size_t size;
350
351 size = nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus));
352 size += nt_size(NT_PRFPREG, sizeof(elf_fpregset_t));
353 size += nt_size(NT_S390_TIMER, sizeof(sa->timer));
354 size += nt_size(NT_S390_TODCMP, sizeof(sa->todcmp));
355 size += nt_size(NT_S390_TODPREG, sizeof(sa->todpreg));
356 size += nt_size(NT_S390_CTRS, sizeof(sa->ctrs));
357 size += nt_size(NT_S390_PREFIX, sizeof(sa->prefix));
358 if (cpu_has_vx()) {
359 size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high));
360 size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low));
361 }
362
363 return size;
364}
365
366/*
367 * Initialize prpsinfo note (new kernel)
368 */
369static void *nt_prpsinfo(void *ptr)
370{
371 struct elf_prpsinfo prpsinfo;
372
373 memset(&prpsinfo, 0, sizeof(prpsinfo));
374 prpsinfo.pr_sname = 'R';
375 strcpy(prpsinfo.pr_fname, "vmlinux");
376 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
377}
378
379/*
380 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
381 */
382static void *get_vmcoreinfo_old(unsigned long *size)
383{
384 char nt_name[11], *vmcoreinfo;
385 unsigned long addr;
386 Elf64_Nhdr note;
387
388 if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr)))
389 return NULL;
390 memset(nt_name, 0, sizeof(nt_name));
391 if (copy_oldmem_kernel(¬e, addr, sizeof(note)))
392 return NULL;
393 if (copy_oldmem_kernel(nt_name, addr + sizeof(note),
394 sizeof(nt_name) - 1))
395 return NULL;
396 if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0)
397 return NULL;
398 vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL);
399 if (!vmcoreinfo)
400 return NULL;
401 if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) {
402 kfree(vmcoreinfo);
403 return NULL;
404 }
405 *size = note.n_descsz;
406 return vmcoreinfo;
407}
408
409/*
410 * Initialize vmcoreinfo note (new kernel)
411 */
412static void *nt_vmcoreinfo(void *ptr)
413{
414 const char *name = VMCOREINFO_NOTE_NAME;
415 unsigned long size;
416 void *vmcoreinfo;
417
418 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
419 if (vmcoreinfo)
420 return nt_init_name(ptr, 0, vmcoreinfo, size, name);
421
422 vmcoreinfo = get_vmcoreinfo_old(&size);
423 if (!vmcoreinfo)
424 return ptr;
425 ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name);
426 kfree(vmcoreinfo);
427 return ptr;
428}
429
430static size_t nt_vmcoreinfo_size(void)
431{
432 const char *name = VMCOREINFO_NOTE_NAME;
433 unsigned long size;
434 void *vmcoreinfo;
435
436 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
437 if (vmcoreinfo)
438 return nt_size_name(size, name);
439
440 vmcoreinfo = get_vmcoreinfo_old(&size);
441 if (!vmcoreinfo)
442 return 0;
443
444 kfree(vmcoreinfo);
445 return nt_size_name(size, name);
446}
447
448/*
449 * Initialize final note (needed for /proc/vmcore code)
450 */
451static void *nt_final(void *ptr)
452{
453 Elf64_Nhdr *note;
454
455 note = (Elf64_Nhdr *) ptr;
456 note->n_namesz = 0;
457 note->n_descsz = 0;
458 note->n_type = 0;
459 return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
460}
461
462/*
463 * Initialize ELF header (new kernel)
464 */
465static void *ehdr_init(Elf64_Ehdr *ehdr, int phdr_count)
466{
467 memset(ehdr, 0, sizeof(*ehdr));
468 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
469 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
470 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
471 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
472 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
473 ehdr->e_type = ET_CORE;
474 ehdr->e_machine = EM_S390;
475 ehdr->e_version = EV_CURRENT;
476 ehdr->e_phoff = sizeof(Elf64_Ehdr);
477 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
478 ehdr->e_phentsize = sizeof(Elf64_Phdr);
479 /* Number of PT_LOAD program headers plus PT_NOTE program header */
480 ehdr->e_phnum = phdr_count + 1;
481 return ehdr + 1;
482}
483
484/*
485 * Return CPU count for ELF header (new kernel)
486 */
487static int get_cpu_cnt(void)
488{
489 struct save_area *sa;
490 int cpus = 0;
491
492 list_for_each_entry(sa, &dump_save_areas, list)
493 if (sa->prefix != 0)
494 cpus++;
495 return cpus;
496}
497
498/*
499 * Return memory chunk count for ELF header (new kernel)
500 */
501static int get_mem_chunk_cnt(void)
502{
503 int cnt = 0;
504 u64 idx;
505
506 for_each_physmem_range(idx, &oldmem_type, NULL, NULL)
507 cnt++;
508 return cnt;
509}
510
511/*
512 * Initialize ELF loads (new kernel)
513 */
514static void loads_init(Elf64_Phdr *phdr, bool os_info_has_vm)
515{
516 unsigned long old_identity_base = 0;
517 phys_addr_t start, end;
518 u64 idx;
519
520 if (os_info_has_vm)
521 old_identity_base = os_info_old_value(OS_INFO_IDENTITY_BASE);
522 for_each_physmem_range(idx, &oldmem_type, &start, &end) {
523 phdr->p_type = PT_LOAD;
524 phdr->p_vaddr = old_identity_base + start;
525 phdr->p_offset = start;
526 phdr->p_paddr = start;
527 phdr->p_filesz = end - start;
528 phdr->p_memsz = end - start;
529 phdr->p_flags = PF_R | PF_W | PF_X;
530 phdr->p_align = PAGE_SIZE;
531 phdr++;
532 }
533}
534
535static bool os_info_has_vm(void)
536{
537 return os_info_old_value(OS_INFO_KASLR_OFFSET);
538}
539
540/*
541 * Prepare PT_LOAD type program header for kernel image region
542 */
543static void text_init(Elf64_Phdr *phdr)
544{
545 unsigned long start_phys = os_info_old_value(OS_INFO_IMAGE_PHYS);
546 unsigned long start = os_info_old_value(OS_INFO_IMAGE_START);
547 unsigned long end = os_info_old_value(OS_INFO_IMAGE_END);
548
549 phdr->p_type = PT_LOAD;
550 phdr->p_vaddr = start;
551 phdr->p_filesz = end - start;
552 phdr->p_memsz = end - start;
553 phdr->p_offset = start_phys;
554 phdr->p_paddr = start_phys;
555 phdr->p_flags = PF_R | PF_W | PF_X;
556 phdr->p_align = PAGE_SIZE;
557}
558
559/*
560 * Initialize notes (new kernel)
561 */
562static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
563{
564 struct save_area *sa;
565 void *ptr_start = ptr;
566 int cpu;
567
568 ptr = nt_prpsinfo(ptr);
569
570 cpu = 1;
571 list_for_each_entry(sa, &dump_save_areas, list)
572 if (sa->prefix != 0)
573 ptr = fill_cpu_elf_notes(ptr, cpu++, sa);
574 ptr = nt_vmcoreinfo(ptr);
575 ptr = nt_final(ptr);
576 memset(phdr, 0, sizeof(*phdr));
577 phdr->p_type = PT_NOTE;
578 phdr->p_offset = notes_offset;
579 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
580 phdr->p_memsz = phdr->p_filesz;
581 return ptr;
582}
583
584static size_t get_elfcorehdr_size(int phdr_count)
585{
586 size_t size;
587
588 size = sizeof(Elf64_Ehdr);
589 /* PT_NOTES */
590 size += sizeof(Elf64_Phdr);
591 /* nt_prpsinfo */
592 size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo));
593 /* regsets */
594 size += get_cpu_cnt() * get_cpu_elf_notes_size();
595 /* nt_vmcoreinfo */
596 size += nt_vmcoreinfo_size();
597 /* nt_final */
598 size += sizeof(Elf64_Nhdr);
599 /* PT_LOADS */
600 size += phdr_count * sizeof(Elf64_Phdr);
601
602 return size;
603}
604
605/*
606 * Create ELF core header (new kernel)
607 */
608int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
609{
610 Elf64_Phdr *phdr_notes, *phdr_loads, *phdr_text;
611 int mem_chunk_cnt, phdr_text_cnt;
612 size_t alloc_size;
613 void *ptr, *hdr;
614 u64 hdr_off;
615
616 /* If we are not in kdump or zfcp/nvme dump mode return */
617 if (!oldmem_data.start && !is_ipl_type_dump())
618 return 0;
619 /* If we cannot get HSA size for zfcp/nvme dump return error */
620 if (is_ipl_type_dump() && !sclp.hsa_size)
621 return -ENODEV;
622
623 /* For kdump, exclude previous crashkernel memory */
624 if (oldmem_data.start) {
625 oldmem_region.base = oldmem_data.start;
626 oldmem_region.size = oldmem_data.size;
627 oldmem_type.total_size = oldmem_data.size;
628 }
629
630 mem_chunk_cnt = get_mem_chunk_cnt();
631 phdr_text_cnt = os_info_has_vm() ? 1 : 0;
632
633 alloc_size = get_elfcorehdr_size(mem_chunk_cnt + phdr_text_cnt);
634
635 hdr = kzalloc(alloc_size, GFP_KERNEL);
636
637 /*
638 * Without elfcorehdr /proc/vmcore cannot be created. Thus creating
639 * a dump with this crash kernel will fail. Panic now to allow other
640 * dump mechanisms to take over.
641 */
642 if (!hdr)
643 panic("s390 kdump allocating elfcorehdr failed");
644
645 /* Init elf header */
646 phdr_notes = ehdr_init(hdr, mem_chunk_cnt + phdr_text_cnt);
647 /* Init program headers */
648 if (phdr_text_cnt) {
649 phdr_text = phdr_notes + 1;
650 phdr_loads = phdr_text + 1;
651 } else {
652 phdr_loads = phdr_notes + 1;
653 }
654 ptr = PTR_ADD(phdr_loads, sizeof(Elf64_Phdr) * mem_chunk_cnt);
655 /* Init notes */
656 hdr_off = PTR_DIFF(ptr, hdr);
657 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
658 /* Init kernel text program header */
659 if (phdr_text_cnt)
660 text_init(phdr_text);
661 /* Init loads */
662 loads_init(phdr_loads, phdr_text_cnt);
663 /* Finalize program headers */
664 hdr_off = PTR_DIFF(ptr, hdr);
665 *addr = (unsigned long long) hdr;
666 *size = (unsigned long long) hdr_off;
667 BUG_ON(elfcorehdr_size > alloc_size);
668 return 0;
669}
670
671/*
672 * Free ELF core header (new kernel)
673 */
674void elfcorehdr_free(unsigned long long addr)
675{
676 kfree((void *)(unsigned long)addr);
677}
678
679/*
680 * Read from ELF header
681 */
682ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
683{
684 void *src = (void *)(unsigned long)*ppos;
685
686 memcpy(buf, src, count);
687 *ppos += count;
688 return count;
689}
690
691/*
692 * Read from ELF notes data
693 */
694ssize_t elfcorehdr_read_notes(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}
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 <asm/asm-offsets.h>
17#include <linux/memblock.h>
18#include <asm/os_info.h>
19#include <asm/elf.h>
20#include <asm/ipl.h>
21#include <asm/sclp.h>
22
23#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
24#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
25#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
26
27static struct memblock_region oldmem_region;
28
29static struct memblock_type oldmem_type = {
30 .cnt = 1,
31 .max = 1,
32 .total_size = 0,
33 .regions = &oldmem_region,
34};
35
36struct save_area {
37 struct list_head list;
38 u64 psw[2];
39 u64 ctrs[16];
40 u64 gprs[16];
41 u32 acrs[16];
42 u64 fprs[16];
43 u32 fpc;
44 u32 prefix;
45 u64 todpreg;
46 u64 timer;
47 u64 todcmp;
48 u64 vxrs_low[16];
49 __vector128 vxrs_high[16];
50};
51
52static LIST_HEAD(dump_save_areas);
53
54/*
55 * Allocate a save area
56 */
57struct save_area * __init save_area_alloc(bool is_boot_cpu)
58{
59 struct save_area *sa;
60
61 sa = (void *) memblock_alloc(sizeof(*sa), 8);
62 if (is_boot_cpu)
63 list_add(&sa->list, &dump_save_areas);
64 else
65 list_add_tail(&sa->list, &dump_save_areas);
66 return sa;
67}
68
69/*
70 * Return the address of the save area for the boot CPU
71 */
72struct save_area * __init save_area_boot_cpu(void)
73{
74 if (list_empty(&dump_save_areas))
75 return NULL;
76 return list_first_entry(&dump_save_areas, struct save_area, list);
77}
78
79/*
80 * Copy CPU registers into the save area
81 */
82void __init save_area_add_regs(struct save_area *sa, void *regs)
83{
84 struct lowcore *lc;
85
86 lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA);
87 memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw));
88 memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs));
89 memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs));
90 memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs));
91 memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs));
92 memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc));
93 memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix));
94 memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg));
95 memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer));
96 memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp));
97}
98
99/*
100 * Copy vector registers into the save area
101 */
102void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
103{
104 int i;
105
106 /* Copy lower halves of vector registers 0-15 */
107 for (i = 0; i < 16; i++)
108 memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8);
109 /* Copy vector registers 16-31 */
110 memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
111}
112
113/*
114 * Return physical address for virtual address
115 */
116static inline void *load_real_addr(void *addr)
117{
118 unsigned long real_addr;
119
120 asm volatile(
121 " lra %0,0(%1)\n"
122 " jz 0f\n"
123 " la %0,0\n"
124 "0:"
125 : "=a" (real_addr) : "a" (addr) : "cc");
126 return (void *)real_addr;
127}
128
129/*
130 * Copy memory of the old, dumped system to a kernel space virtual address
131 */
132int copy_oldmem_kernel(void *dst, void *src, size_t count)
133{
134 unsigned long from, len;
135 void *ra;
136 int rc;
137
138 while (count) {
139 from = __pa(src);
140 if (!OLDMEM_BASE && from < sclp.hsa_size) {
141 /* Copy from zfcpdump HSA area */
142 len = min(count, sclp.hsa_size - from);
143 rc = memcpy_hsa_kernel(dst, from, len);
144 if (rc)
145 return rc;
146 } else {
147 /* Check for swapped kdump oldmem areas */
148 if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) {
149 from -= OLDMEM_BASE;
150 len = min(count, OLDMEM_SIZE - from);
151 } else if (OLDMEM_BASE && from < OLDMEM_SIZE) {
152 len = min(count, OLDMEM_SIZE - from);
153 from += OLDMEM_BASE;
154 } else {
155 len = count;
156 }
157 if (is_vmalloc_or_module_addr(dst)) {
158 ra = load_real_addr(dst);
159 len = min(PAGE_SIZE - offset_in_page(ra), len);
160 } else {
161 ra = dst;
162 }
163 if (memcpy_real(ra, (void *) from, len))
164 return -EFAULT;
165 }
166 dst += len;
167 src += len;
168 count -= len;
169 }
170 return 0;
171}
172
173/*
174 * Copy memory of the old, dumped system to a user space virtual address
175 */
176int copy_oldmem_user(void __user *dst, void *src, size_t count)
177{
178 unsigned long from, len;
179 int rc;
180
181 while (count) {
182 from = __pa(src);
183 if (!OLDMEM_BASE && from < sclp.hsa_size) {
184 /* Copy from zfcpdump HSA area */
185 len = min(count, sclp.hsa_size - from);
186 rc = memcpy_hsa_user(dst, from, len);
187 if (rc)
188 return rc;
189 } else {
190 /* Check for swapped kdump oldmem areas */
191 if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) {
192 from -= OLDMEM_BASE;
193 len = min(count, OLDMEM_SIZE - from);
194 } else if (OLDMEM_BASE && from < OLDMEM_SIZE) {
195 len = min(count, OLDMEM_SIZE - from);
196 from += OLDMEM_BASE;
197 } else {
198 len = count;
199 }
200 rc = copy_to_user_real(dst, (void *) from, count);
201 if (rc)
202 return rc;
203 }
204 dst += len;
205 src += len;
206 count -= len;
207 }
208 return 0;
209}
210
211/*
212 * Copy one page from "oldmem"
213 */
214ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
215 unsigned long offset, int userbuf)
216{
217 void *src;
218 int rc;
219
220 if (!csize)
221 return 0;
222 src = (void *) (pfn << PAGE_SHIFT) + offset;
223 if (userbuf)
224 rc = copy_oldmem_user((void __force __user *) buf, src, csize);
225 else
226 rc = copy_oldmem_kernel((void *) buf, src, csize);
227 return rc;
228}
229
230/*
231 * Remap "oldmem" for kdump
232 *
233 * For the kdump reserved memory this functions performs a swap operation:
234 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
235 */
236static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
237 unsigned long from, unsigned long pfn,
238 unsigned long size, pgprot_t prot)
239{
240 unsigned long size_old;
241 int rc;
242
243 if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
244 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
245 rc = remap_pfn_range(vma, from,
246 pfn + (OLDMEM_BASE >> PAGE_SHIFT),
247 size_old, prot);
248 if (rc || size == size_old)
249 return rc;
250 size -= size_old;
251 from += size_old;
252 pfn += size_old >> PAGE_SHIFT;
253 }
254 return remap_pfn_range(vma, from, pfn, size, prot);
255}
256
257/*
258 * Remap "oldmem" for zfcpdump
259 *
260 * We only map available memory above HSA size. Memory below HSA size
261 * is read on demand using the copy_oldmem_page() function.
262 */
263static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
264 unsigned long from,
265 unsigned long pfn,
266 unsigned long size, pgprot_t prot)
267{
268 unsigned long hsa_end = sclp.hsa_size;
269 unsigned long size_hsa;
270
271 if (pfn < hsa_end >> PAGE_SHIFT) {
272 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
273 if (size == size_hsa)
274 return 0;
275 size -= size_hsa;
276 from += size_hsa;
277 pfn += size_hsa >> PAGE_SHIFT;
278 }
279 return remap_pfn_range(vma, from, pfn, size, prot);
280}
281
282/*
283 * Remap "oldmem" for kdump or zfcpdump
284 */
285int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
286 unsigned long pfn, unsigned long size, pgprot_t prot)
287{
288 if (OLDMEM_BASE)
289 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
290 else
291 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
292 prot);
293}
294
295/*
296 * Alloc memory and panic in case of ENOMEM
297 */
298static void *kzalloc_panic(int len)
299{
300 void *rc;
301
302 rc = kzalloc(len, GFP_KERNEL);
303 if (!rc)
304 panic("s390 kdump kzalloc (%d) failed", len);
305 return rc;
306}
307
308/*
309 * Initialize ELF note
310 */
311static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
312 const char *name)
313{
314 Elf64_Nhdr *note;
315 u64 len;
316
317 note = (Elf64_Nhdr *)buf;
318 note->n_namesz = strlen(name) + 1;
319 note->n_descsz = d_len;
320 note->n_type = type;
321 len = sizeof(Elf64_Nhdr);
322
323 memcpy(buf + len, name, note->n_namesz);
324 len = roundup(len + note->n_namesz, 4);
325
326 memcpy(buf + len, desc, note->n_descsz);
327 len = roundup(len + note->n_descsz, 4);
328
329 return PTR_ADD(buf, len);
330}
331
332static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
333{
334 return nt_init_name(buf, type, desc, d_len, KEXEC_CORE_NOTE_NAME);
335}
336
337/*
338 * Fill ELF notes for one CPU with save area registers
339 */
340static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
341{
342 struct elf_prstatus nt_prstatus;
343 elf_fpregset_t nt_fpregset;
344
345 /* Prepare prstatus note */
346 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
347 memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
348 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
349 memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
350 nt_prstatus.pr_pid = cpu;
351 /* Prepare fpregset (floating point) note */
352 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
353 memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
354 memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
355 /* Create ELF notes for the CPU */
356 ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
357 ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
358 ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
359 ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
360 ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
361 ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
362 ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
363 if (MACHINE_HAS_VX) {
364 ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
365 &sa->vxrs_high, sizeof(sa->vxrs_high));
366 ptr = nt_init(ptr, NT_S390_VXRS_LOW,
367 &sa->vxrs_low, sizeof(sa->vxrs_low));
368 }
369 return ptr;
370}
371
372/*
373 * Initialize prpsinfo note (new kernel)
374 */
375static void *nt_prpsinfo(void *ptr)
376{
377 struct elf_prpsinfo prpsinfo;
378
379 memset(&prpsinfo, 0, sizeof(prpsinfo));
380 prpsinfo.pr_sname = 'R';
381 strcpy(prpsinfo.pr_fname, "vmlinux");
382 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
383}
384
385/*
386 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
387 */
388static void *get_vmcoreinfo_old(unsigned long *size)
389{
390 char nt_name[11], *vmcoreinfo;
391 Elf64_Nhdr note;
392 void *addr;
393
394 if (copy_oldmem_kernel(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
395 return NULL;
396 memset(nt_name, 0, sizeof(nt_name));
397 if (copy_oldmem_kernel(¬e, addr, sizeof(note)))
398 return NULL;
399 if (copy_oldmem_kernel(nt_name, addr + sizeof(note),
400 sizeof(nt_name) - 1))
401 return NULL;
402 if (strcmp(nt_name, "VMCOREINFO") != 0)
403 return NULL;
404 vmcoreinfo = kzalloc_panic(note.n_descsz);
405 if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz))
406 return NULL;
407 *size = note.n_descsz;
408 return vmcoreinfo;
409}
410
411/*
412 * Initialize vmcoreinfo note (new kernel)
413 */
414static void *nt_vmcoreinfo(void *ptr)
415{
416 unsigned long size;
417 void *vmcoreinfo;
418
419 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
420 if (!vmcoreinfo)
421 vmcoreinfo = get_vmcoreinfo_old(&size);
422 if (!vmcoreinfo)
423 return ptr;
424 return nt_init_name(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
425}
426
427/*
428 * Initialize ELF header (new kernel)
429 */
430static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
431{
432 memset(ehdr, 0, sizeof(*ehdr));
433 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
434 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
435 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
436 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
437 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
438 ehdr->e_type = ET_CORE;
439 ehdr->e_machine = EM_S390;
440 ehdr->e_version = EV_CURRENT;
441 ehdr->e_phoff = sizeof(Elf64_Ehdr);
442 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
443 ehdr->e_phentsize = sizeof(Elf64_Phdr);
444 ehdr->e_phnum = mem_chunk_cnt + 1;
445 return ehdr + 1;
446}
447
448/*
449 * Return CPU count for ELF header (new kernel)
450 */
451static int get_cpu_cnt(void)
452{
453 struct save_area *sa;
454 int cpus = 0;
455
456 list_for_each_entry(sa, &dump_save_areas, list)
457 if (sa->prefix != 0)
458 cpus++;
459 return cpus;
460}
461
462/*
463 * Return memory chunk count for ELF header (new kernel)
464 */
465static int get_mem_chunk_cnt(void)
466{
467 int cnt = 0;
468 u64 idx;
469
470 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
471 MEMBLOCK_NONE, NULL, NULL, NULL)
472 cnt++;
473 return cnt;
474}
475
476/*
477 * Initialize ELF loads (new kernel)
478 */
479static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
480{
481 phys_addr_t start, end;
482 u64 idx;
483
484 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
485 MEMBLOCK_NONE, &start, &end, NULL) {
486 phdr->p_filesz = end - start;
487 phdr->p_type = PT_LOAD;
488 phdr->p_offset = start;
489 phdr->p_vaddr = start;
490 phdr->p_paddr = start;
491 phdr->p_memsz = end - start;
492 phdr->p_flags = PF_R | PF_W | PF_X;
493 phdr->p_align = PAGE_SIZE;
494 phdr++;
495 }
496}
497
498/*
499 * Initialize notes (new kernel)
500 */
501static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
502{
503 struct save_area *sa;
504 void *ptr_start = ptr;
505 int cpu;
506
507 ptr = nt_prpsinfo(ptr);
508
509 cpu = 1;
510 list_for_each_entry(sa, &dump_save_areas, list)
511 if (sa->prefix != 0)
512 ptr = fill_cpu_elf_notes(ptr, cpu++, sa);
513 ptr = nt_vmcoreinfo(ptr);
514 memset(phdr, 0, sizeof(*phdr));
515 phdr->p_type = PT_NOTE;
516 phdr->p_offset = notes_offset;
517 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
518 phdr->p_memsz = phdr->p_filesz;
519 return ptr;
520}
521
522/*
523 * Create ELF core header (new kernel)
524 */
525int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
526{
527 Elf64_Phdr *phdr_notes, *phdr_loads;
528 int mem_chunk_cnt;
529 void *ptr, *hdr;
530 u32 alloc_size;
531 u64 hdr_off;
532
533 /* If we are not in kdump or zfcpdump mode return */
534 if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
535 return 0;
536 /* If we cannot get HSA size for zfcpdump return error */
537 if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp.hsa_size)
538 return -ENODEV;
539
540 /* For kdump, exclude previous crashkernel memory */
541 if (OLDMEM_BASE) {
542 oldmem_region.base = OLDMEM_BASE;
543 oldmem_region.size = OLDMEM_SIZE;
544 oldmem_type.total_size = OLDMEM_SIZE;
545 }
546
547 mem_chunk_cnt = get_mem_chunk_cnt();
548
549 alloc_size = 0x1000 + get_cpu_cnt() * 0x4a0 +
550 mem_chunk_cnt * sizeof(Elf64_Phdr);
551 hdr = kzalloc_panic(alloc_size);
552 /* Init elf header */
553 ptr = ehdr_init(hdr, mem_chunk_cnt);
554 /* Init program headers */
555 phdr_notes = ptr;
556 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
557 phdr_loads = ptr;
558 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
559 /* Init notes */
560 hdr_off = PTR_DIFF(ptr, hdr);
561 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
562 /* Init loads */
563 hdr_off = PTR_DIFF(ptr, hdr);
564 loads_init(phdr_loads, hdr_off);
565 *addr = (unsigned long long) hdr;
566 *size = (unsigned long long) hdr_off;
567 BUG_ON(elfcorehdr_size > alloc_size);
568 return 0;
569}
570
571/*
572 * Free ELF core header (new kernel)
573 */
574void elfcorehdr_free(unsigned long long addr)
575{
576 kfree((void *)(unsigned long)addr);
577}
578
579/*
580 * Read from ELF header
581 */
582ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
583{
584 void *src = (void *)(unsigned long)*ppos;
585
586 memcpy(buf, src, count);
587 *ppos += count;
588 return count;
589}
590
591/*
592 * Read from ELF notes data
593 */
594ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
595{
596 void *src = (void *)(unsigned long)*ppos;
597
598 memcpy(buf, src, count);
599 *ppos += count;
600 return count;
601}