1 // SPDX-License-Identifier: GPL-2.0
3 * S390 kdump implementation
5 * Copyright IBM Corp. 2011
6 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
9 #include <linux/crash_dump.h>
10 #include <asm/lowcore.h>
11 #include <linux/kernel.h>
12 #include <linux/init.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>
24 #include <asm/maccess.h>
26 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
27 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
28 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
30 static struct memblock_region oldmem_region;
32 static struct memblock_type oldmem_type = {
36 .regions = &oldmem_region,
41 struct list_head list;
53 __vector128 vxrs_high[16];
56 static LIST_HEAD(dump_save_areas);
59 * Allocate a save area
61 struct save_area * __init save_area_alloc(bool is_boot_cpu)
65 sa = memblock_alloc(sizeof(*sa), 8);
70 list_add(&sa->list, &dump_save_areas);
72 list_add_tail(&sa->list, &dump_save_areas);
77 * Return the address of the save area for the boot CPU
79 struct save_area * __init save_area_boot_cpu(void)
81 return list_first_entry_or_null(&dump_save_areas, struct save_area, list);
85 * Copy CPU registers into the save area
87 void __init save_area_add_regs(struct save_area *sa, void *regs)
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));
105 * Copy vector registers into the save area
107 void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
111 /* Copy lower halves of vector registers 0-15 */
112 for (i = 0; i < 16; i++)
113 memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8);
114 /* Copy vector registers 16-31 */
115 memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
118 static size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
120 size_t len, copied, res = 0;
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);
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;
138 copied = memcpy_real_iter(iter, src, len);
149 int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
151 struct iov_iter iter;
155 kvec.iov_len = count;
156 iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
157 if (copy_oldmem_iter(&iter, src, count) < count)
163 * Copy one page from "oldmem"
165 ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
166 unsigned long offset)
170 src = pfn_to_phys(pfn) + offset;
171 return copy_oldmem_iter(iter, src, csize);
175 * Remap "oldmem" for kdump
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]
180 static 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)
184 unsigned long size_old;
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),
192 if (rc || size == size_old)
196 pfn += size_old >> PAGE_SHIFT;
198 return remap_pfn_range(vma, from, pfn, size, prot);
202 * Remap "oldmem" for zfcp/nvme dump
204 * We only map available memory above HSA size. Memory below HSA size
205 * is read on demand using the copy_oldmem_page() function.
207 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
210 unsigned long size, pgprot_t prot)
212 unsigned long hsa_end = sclp.hsa_size;
213 unsigned long size_hsa;
215 if (pfn < hsa_end >> PAGE_SHIFT) {
216 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
217 if (size == size_hsa)
221 pfn += size_hsa >> PAGE_SHIFT;
223 return remap_pfn_range(vma, from, pfn, size, prot);
227 * Remap "oldmem" for kdump or zfcp/nvme dump
229 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
230 unsigned long pfn, unsigned long size, pgprot_t prot)
232 if (oldmem_data.start)
233 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
235 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
239 static const char *nt_name(Elf64_Word type)
241 const char *name = "LINUX";
243 if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG)
244 name = KEXEC_CORE_NOTE_NAME;
249 * Initialize ELF note
251 static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
257 note = (Elf64_Nhdr *)buf;
258 note->n_namesz = strlen(name) + 1;
259 note->n_descsz = d_len;
261 len = sizeof(Elf64_Nhdr);
263 memcpy(buf + len, name, note->n_namesz);
264 len = roundup(len + note->n_namesz, 4);
266 memcpy(buf + len, desc, note->n_descsz);
267 len = roundup(len + note->n_descsz, 4);
269 return PTR_ADD(buf, len);
272 static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
274 return nt_init_name(buf, type, desc, d_len, nt_name(type));
278 * Calculate the size of ELF note
280 static size_t nt_size_name(int d_len, const char *name)
284 size = sizeof(Elf64_Nhdr);
285 size += roundup(strlen(name) + 1, 4);
286 size += roundup(d_len, 4);
291 static inline size_t nt_size(Elf64_Word type, int d_len)
293 return nt_size_name(d_len, nt_name(type));
297 * Fill ELF notes for one CPU with save area registers
299 static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
301 struct elf_prstatus nt_prstatus;
302 elf_fpregset_t nt_fpregset;
304 /* Prepare prstatus note */
305 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
306 memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
307 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
308 memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
309 nt_prstatus.common.pr_pid = cpu;
310 /* Prepare fpregset (floating point) note */
311 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
312 memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
313 memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
314 /* Create ELF notes for the CPU */
315 ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
316 ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
317 ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
318 ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
319 ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
320 ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
321 ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
322 if (MACHINE_HAS_VX) {
323 ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
324 &sa->vxrs_high, sizeof(sa->vxrs_high));
325 ptr = nt_init(ptr, NT_S390_VXRS_LOW,
326 &sa->vxrs_low, sizeof(sa->vxrs_low));
332 * Calculate size of ELF notes per cpu
334 static size_t get_cpu_elf_notes_size(void)
336 struct save_area *sa = NULL;
339 size = nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus));
340 size += nt_size(NT_PRFPREG, sizeof(elf_fpregset_t));
341 size += nt_size(NT_S390_TIMER, sizeof(sa->timer));
342 size += nt_size(NT_S390_TODCMP, sizeof(sa->todcmp));
343 size += nt_size(NT_S390_TODPREG, sizeof(sa->todpreg));
344 size += nt_size(NT_S390_CTRS, sizeof(sa->ctrs));
345 size += nt_size(NT_S390_PREFIX, sizeof(sa->prefix));
346 if (MACHINE_HAS_VX) {
347 size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high));
348 size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low));
355 * Initialize prpsinfo note (new kernel)
357 static void *nt_prpsinfo(void *ptr)
359 struct elf_prpsinfo prpsinfo;
361 memset(&prpsinfo, 0, sizeof(prpsinfo));
362 prpsinfo.pr_sname = 'R';
363 strcpy(prpsinfo.pr_fname, "vmlinux");
364 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
368 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
370 static void *get_vmcoreinfo_old(unsigned long *size)
372 char nt_name[11], *vmcoreinfo;
376 if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr)))
378 memset(nt_name, 0, sizeof(nt_name));
379 if (copy_oldmem_kernel(¬e, addr, sizeof(note)))
381 if (copy_oldmem_kernel(nt_name, addr + sizeof(note),
382 sizeof(nt_name) - 1))
384 if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0)
386 vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL);
389 if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) {
393 *size = note.n_descsz;
398 * Initialize vmcoreinfo note (new kernel)
400 static void *nt_vmcoreinfo(void *ptr)
402 const char *name = VMCOREINFO_NOTE_NAME;
406 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
408 return nt_init_name(ptr, 0, vmcoreinfo, size, name);
410 vmcoreinfo = get_vmcoreinfo_old(&size);
413 ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name);
418 static size_t nt_vmcoreinfo_size(void)
420 const char *name = VMCOREINFO_NOTE_NAME;
424 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
426 return nt_size_name(size, name);
428 vmcoreinfo = get_vmcoreinfo_old(&size);
433 return nt_size_name(size, name);
437 * Initialize final note (needed for /proc/vmcore code)
439 static void *nt_final(void *ptr)
443 note = (Elf64_Nhdr *) ptr;
447 return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
451 * Initialize ELF header (new kernel)
453 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
455 memset(ehdr, 0, sizeof(*ehdr));
456 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
457 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
458 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
459 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
460 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
461 ehdr->e_type = ET_CORE;
462 ehdr->e_machine = EM_S390;
463 ehdr->e_version = EV_CURRENT;
464 ehdr->e_phoff = sizeof(Elf64_Ehdr);
465 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
466 ehdr->e_phentsize = sizeof(Elf64_Phdr);
467 ehdr->e_phnum = mem_chunk_cnt + 1;
472 * Return CPU count for ELF header (new kernel)
474 static int get_cpu_cnt(void)
476 struct save_area *sa;
479 list_for_each_entry(sa, &dump_save_areas, list)
486 * Return memory chunk count for ELF header (new kernel)
488 static int get_mem_chunk_cnt(void)
493 for_each_physmem_range(idx, &oldmem_type, NULL, NULL)
499 * Initialize ELF loads (new kernel)
501 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
503 phys_addr_t start, end;
506 for_each_physmem_range(idx, &oldmem_type, &start, &end) {
507 phdr->p_filesz = end - start;
508 phdr->p_type = PT_LOAD;
509 phdr->p_offset = start;
510 phdr->p_vaddr = start;
511 phdr->p_paddr = start;
512 phdr->p_memsz = end - start;
513 phdr->p_flags = PF_R | PF_W | PF_X;
514 phdr->p_align = PAGE_SIZE;
520 * Initialize notes (new kernel)
522 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
524 struct save_area *sa;
525 void *ptr_start = ptr;
528 ptr = nt_prpsinfo(ptr);
531 list_for_each_entry(sa, &dump_save_areas, list)
533 ptr = fill_cpu_elf_notes(ptr, cpu++, sa);
534 ptr = nt_vmcoreinfo(ptr);
536 memset(phdr, 0, sizeof(*phdr));
537 phdr->p_type = PT_NOTE;
538 phdr->p_offset = notes_offset;
539 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
540 phdr->p_memsz = phdr->p_filesz;
544 static size_t get_elfcorehdr_size(int mem_chunk_cnt)
548 size = sizeof(Elf64_Ehdr);
550 size += sizeof(Elf64_Phdr);
552 size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo));
554 size += get_cpu_cnt() * get_cpu_elf_notes_size();
556 size += nt_vmcoreinfo_size();
558 size += sizeof(Elf64_Nhdr);
560 size += mem_chunk_cnt * sizeof(Elf64_Phdr);
566 * Create ELF core header (new kernel)
568 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
570 Elf64_Phdr *phdr_notes, *phdr_loads;
576 /* If we are not in kdump or zfcp/nvme dump mode return */
577 if (!oldmem_data.start && !is_ipl_type_dump())
579 /* If we cannot get HSA size for zfcp/nvme dump return error */
580 if (is_ipl_type_dump() && !sclp.hsa_size)
583 /* For kdump, exclude previous crashkernel memory */
584 if (oldmem_data.start) {
585 oldmem_region.base = oldmem_data.start;
586 oldmem_region.size = oldmem_data.size;
587 oldmem_type.total_size = oldmem_data.size;
590 mem_chunk_cnt = get_mem_chunk_cnt();
592 alloc_size = get_elfcorehdr_size(mem_chunk_cnt);
594 hdr = kzalloc(alloc_size, GFP_KERNEL);
596 /* Without elfcorehdr /proc/vmcore cannot be created. Thus creating
597 * a dump with this crash kernel will fail. Panic now to allow other
598 * dump mechanisms to take over.
601 panic("s390 kdump allocating elfcorehdr failed");
603 /* Init elf header */
604 ptr = ehdr_init(hdr, mem_chunk_cnt);
605 /* Init program headers */
607 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
609 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
611 hdr_off = PTR_DIFF(ptr, hdr);
612 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
614 hdr_off = PTR_DIFF(ptr, hdr);
615 loads_init(phdr_loads, hdr_off);
616 *addr = (unsigned long long) hdr;
617 *size = (unsigned long long) hdr_off;
618 BUG_ON(elfcorehdr_size > alloc_size);
623 * Free ELF core header (new kernel)
625 void elfcorehdr_free(unsigned long long addr)
627 kfree((void *)(unsigned long)addr);
631 * Read from ELF header
633 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
635 void *src = (void *)(unsigned long)*ppos;
637 memcpy(buf, src, count);
643 * Read from ELF notes data
645 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
647 void *src = (void *)(unsigned long)*ppos;
649 memcpy(buf, src, count);