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/bootmem.h>
17 #include <linux/elf.h>
18 #include <asm/asm-offsets.h>
19 #include <linux/memblock.h>
20 #include <asm/os_info.h>
25 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
26 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
27 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
29 static struct memblock_region oldmem_region;
31 static struct memblock_type oldmem_type = {
35 .regions = &oldmem_region,
40 struct list_head list;
52 __vector128 vxrs_high[16];
55 static LIST_HEAD(dump_save_areas);
58 * Allocate a save area
60 struct save_area * __init save_area_alloc(bool is_boot_cpu)
64 sa = (void *) memblock_alloc(sizeof(*sa), 8);
66 list_add(&sa->list, &dump_save_areas);
68 list_add_tail(&sa->list, &dump_save_areas);
73 * Return the address of the save area for the boot CPU
75 struct save_area * __init save_area_boot_cpu(void)
77 return list_first_entry_or_null(&dump_save_areas, struct save_area, list);
81 * Copy CPU registers into the save area
83 void __init save_area_add_regs(struct save_area *sa, void *regs)
87 lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA);
88 memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw));
89 memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs));
90 memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs));
91 memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs));
92 memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs));
93 memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc));
94 memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix));
95 memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg));
96 memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer));
97 memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp));
101 * Copy vector registers into the save area
103 void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
107 /* Copy lower halves of vector registers 0-15 */
108 for (i = 0; i < 16; i++)
109 memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8);
110 /* Copy vector registers 16-31 */
111 memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
115 * Return physical address for virtual address
117 static inline void *load_real_addr(void *addr)
119 unsigned long real_addr;
126 : "=a" (real_addr) : "a" (addr) : "cc");
127 return (void *)real_addr;
131 * Copy memory of the old, dumped system to a kernel space virtual address
133 int copy_oldmem_kernel(void *dst, void *src, size_t count)
135 unsigned long from, len;
141 if (!OLDMEM_BASE && from < sclp.hsa_size) {
142 /* Copy from zfcpdump HSA area */
143 len = min(count, sclp.hsa_size - from);
144 rc = memcpy_hsa_kernel(dst, from, len);
148 /* Check for swapped kdump oldmem areas */
149 if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) {
151 len = min(count, OLDMEM_SIZE - from);
152 } else if (OLDMEM_BASE && from < OLDMEM_SIZE) {
153 len = min(count, OLDMEM_SIZE - from);
158 if (is_vmalloc_or_module_addr(dst)) {
159 ra = load_real_addr(dst);
160 len = min(PAGE_SIZE - offset_in_page(ra), len);
164 if (memcpy_real(ra, (void *) from, len))
175 * Copy memory of the old, dumped system to a user space virtual address
177 static int copy_oldmem_user(void __user *dst, void *src, size_t count)
179 unsigned long from, len;
184 if (!OLDMEM_BASE && from < sclp.hsa_size) {
185 /* Copy from zfcpdump HSA area */
186 len = min(count, sclp.hsa_size - from);
187 rc = memcpy_hsa_user(dst, from, len);
191 /* Check for swapped kdump oldmem areas */
192 if (OLDMEM_BASE && from - OLDMEM_BASE < OLDMEM_SIZE) {
194 len = min(count, OLDMEM_SIZE - from);
195 } else if (OLDMEM_BASE && from < OLDMEM_SIZE) {
196 len = min(count, OLDMEM_SIZE - from);
201 rc = copy_to_user_real(dst, (void *) from, count);
213 * Copy one page from "oldmem"
215 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
216 unsigned long offset, int userbuf)
223 src = (void *) (pfn << PAGE_SHIFT) + offset;
225 rc = copy_oldmem_user((void __force __user *) buf, src, csize);
227 rc = copy_oldmem_kernel((void *) buf, src, csize);
232 * Remap "oldmem" for kdump
234 * For the kdump reserved memory this functions performs a swap operation:
235 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
237 static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
238 unsigned long from, unsigned long pfn,
239 unsigned long size, pgprot_t prot)
241 unsigned long size_old;
244 if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
245 size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
246 rc = remap_pfn_range(vma, from,
247 pfn + (OLDMEM_BASE >> PAGE_SHIFT),
249 if (rc || size == size_old)
253 pfn += size_old >> PAGE_SHIFT;
255 return remap_pfn_range(vma, from, pfn, size, prot);
259 * Remap "oldmem" for zfcpdump
261 * We only map available memory above HSA size. Memory below HSA size
262 * is read on demand using the copy_oldmem_page() function.
264 static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
267 unsigned long size, pgprot_t prot)
269 unsigned long hsa_end = sclp.hsa_size;
270 unsigned long size_hsa;
272 if (pfn < hsa_end >> PAGE_SHIFT) {
273 size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
274 if (size == size_hsa)
278 pfn += size_hsa >> PAGE_SHIFT;
280 return remap_pfn_range(vma, from, pfn, size, prot);
284 * Remap "oldmem" for kdump or zfcpdump
286 int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
287 unsigned long pfn, unsigned long size, pgprot_t prot)
290 return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
292 return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
296 static const char *nt_name(Elf64_Word type)
298 const char *name = "LINUX";
300 if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG)
301 name = KEXEC_CORE_NOTE_NAME;
306 * Initialize ELF note
308 static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
314 note = (Elf64_Nhdr *)buf;
315 note->n_namesz = strlen(name) + 1;
316 note->n_descsz = d_len;
318 len = sizeof(Elf64_Nhdr);
320 memcpy(buf + len, name, note->n_namesz);
321 len = roundup(len + note->n_namesz, 4);
323 memcpy(buf + len, desc, note->n_descsz);
324 len = roundup(len + note->n_descsz, 4);
326 return PTR_ADD(buf, len);
329 static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
331 return nt_init_name(buf, type, desc, d_len, nt_name(type));
335 * Calculate the size of ELF note
337 static size_t nt_size_name(int d_len, const char *name)
341 size = sizeof(Elf64_Nhdr);
342 size += roundup(strlen(name) + 1, 4);
343 size += roundup(d_len, 4);
348 static inline size_t nt_size(Elf64_Word type, int d_len)
350 return nt_size_name(d_len, nt_name(type));
354 * Fill ELF notes for one CPU with save area registers
356 static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
358 struct elf_prstatus nt_prstatus;
359 elf_fpregset_t nt_fpregset;
361 /* Prepare prstatus note */
362 memset(&nt_prstatus, 0, sizeof(nt_prstatus));
363 memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
364 memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
365 memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
366 nt_prstatus.pr_pid = cpu;
367 /* Prepare fpregset (floating point) note */
368 memset(&nt_fpregset, 0, sizeof(nt_fpregset));
369 memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
370 memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
371 /* Create ELF notes for the CPU */
372 ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
373 ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
374 ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
375 ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
376 ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
377 ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
378 ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
379 if (MACHINE_HAS_VX) {
380 ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
381 &sa->vxrs_high, sizeof(sa->vxrs_high));
382 ptr = nt_init(ptr, NT_S390_VXRS_LOW,
383 &sa->vxrs_low, sizeof(sa->vxrs_low));
389 * Calculate size of ELF notes per cpu
391 static size_t get_cpu_elf_notes_size(void)
393 struct save_area *sa = NULL;
396 size = nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus));
397 size += nt_size(NT_PRFPREG, sizeof(elf_fpregset_t));
398 size += nt_size(NT_S390_TIMER, sizeof(sa->timer));
399 size += nt_size(NT_S390_TODCMP, sizeof(sa->todcmp));
400 size += nt_size(NT_S390_TODPREG, sizeof(sa->todpreg));
401 size += nt_size(NT_S390_CTRS, sizeof(sa->ctrs));
402 size += nt_size(NT_S390_PREFIX, sizeof(sa->prefix));
403 if (MACHINE_HAS_VX) {
404 size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high));
405 size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low));
412 * Initialize prpsinfo note (new kernel)
414 static void *nt_prpsinfo(void *ptr)
416 struct elf_prpsinfo prpsinfo;
418 memset(&prpsinfo, 0, sizeof(prpsinfo));
419 prpsinfo.pr_sname = 'R';
420 strcpy(prpsinfo.pr_fname, "vmlinux");
421 return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
425 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
427 static void *get_vmcoreinfo_old(unsigned long *size)
429 char nt_name[11], *vmcoreinfo;
433 if (copy_oldmem_kernel(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
435 memset(nt_name, 0, sizeof(nt_name));
436 if (copy_oldmem_kernel(¬e, addr, sizeof(note)))
438 if (copy_oldmem_kernel(nt_name, addr + sizeof(note),
439 sizeof(nt_name) - 1))
441 if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0)
443 vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL);
446 if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) {
450 *size = note.n_descsz;
455 * Initialize vmcoreinfo note (new kernel)
457 static void *nt_vmcoreinfo(void *ptr)
459 const char *name = VMCOREINFO_NOTE_NAME;
463 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
465 return nt_init_name(ptr, 0, vmcoreinfo, size, name);
467 vmcoreinfo = get_vmcoreinfo_old(&size);
470 ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name);
475 static size_t nt_vmcoreinfo_size(void)
477 const char *name = VMCOREINFO_NOTE_NAME;
481 vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
483 return nt_size_name(size, name);
485 vmcoreinfo = get_vmcoreinfo_old(&size);
490 return nt_size_name(size, name);
494 * Initialize final note (needed for /proc/vmcore code)
496 static void *nt_final(void *ptr)
500 note = (Elf64_Nhdr *) ptr;
504 return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
508 * Initialize ELF header (new kernel)
510 static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
512 memset(ehdr, 0, sizeof(*ehdr));
513 memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
514 ehdr->e_ident[EI_CLASS] = ELFCLASS64;
515 ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
516 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
517 memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
518 ehdr->e_type = ET_CORE;
519 ehdr->e_machine = EM_S390;
520 ehdr->e_version = EV_CURRENT;
521 ehdr->e_phoff = sizeof(Elf64_Ehdr);
522 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
523 ehdr->e_phentsize = sizeof(Elf64_Phdr);
524 ehdr->e_phnum = mem_chunk_cnt + 1;
529 * Return CPU count for ELF header (new kernel)
531 static int get_cpu_cnt(void)
533 struct save_area *sa;
536 list_for_each_entry(sa, &dump_save_areas, list)
543 * Return memory chunk count for ELF header (new kernel)
545 static int get_mem_chunk_cnt(void)
550 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
551 MEMBLOCK_NONE, NULL, NULL, NULL)
557 * Initialize ELF loads (new kernel)
559 static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
561 phys_addr_t start, end;
564 for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
565 MEMBLOCK_NONE, &start, &end, NULL) {
566 phdr->p_filesz = end - start;
567 phdr->p_type = PT_LOAD;
568 phdr->p_offset = start;
569 phdr->p_vaddr = start;
570 phdr->p_paddr = start;
571 phdr->p_memsz = end - start;
572 phdr->p_flags = PF_R | PF_W | PF_X;
573 phdr->p_align = PAGE_SIZE;
579 * Initialize notes (new kernel)
581 static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
583 struct save_area *sa;
584 void *ptr_start = ptr;
587 ptr = nt_prpsinfo(ptr);
590 list_for_each_entry(sa, &dump_save_areas, list)
592 ptr = fill_cpu_elf_notes(ptr, cpu++, sa);
593 ptr = nt_vmcoreinfo(ptr);
595 memset(phdr, 0, sizeof(*phdr));
596 phdr->p_type = PT_NOTE;
597 phdr->p_offset = notes_offset;
598 phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
599 phdr->p_memsz = phdr->p_filesz;
603 static size_t get_elfcorehdr_size(int mem_chunk_cnt)
607 size = sizeof(Elf64_Ehdr);
609 size += sizeof(Elf64_Phdr);
611 size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo));
613 size += get_cpu_cnt() * get_cpu_elf_notes_size();
615 size += nt_vmcoreinfo_size();
617 size += sizeof(Elf64_Nhdr);
619 size += mem_chunk_cnt * sizeof(Elf64_Phdr);
625 * Create ELF core header (new kernel)
627 int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
629 Elf64_Phdr *phdr_notes, *phdr_loads;
635 /* If we are not in kdump or zfcpdump mode return */
636 if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
638 /* If we cannot get HSA size for zfcpdump return error */
639 if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp.hsa_size)
642 /* For kdump, exclude previous crashkernel memory */
644 oldmem_region.base = OLDMEM_BASE;
645 oldmem_region.size = OLDMEM_SIZE;
646 oldmem_type.total_size = OLDMEM_SIZE;
649 mem_chunk_cnt = get_mem_chunk_cnt();
651 alloc_size = get_elfcorehdr_size(mem_chunk_cnt);
653 hdr = kzalloc(alloc_size, GFP_KERNEL);
655 /* Without elfcorehdr /proc/vmcore cannot be created. Thus creating
656 * a dump with this crash kernel will fail. Panic now to allow other
657 * dump mechanisms to take over.
660 panic("s390 kdump allocating elfcorehdr failed");
662 /* Init elf header */
663 ptr = ehdr_init(hdr, mem_chunk_cnt);
664 /* Init program headers */
666 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
668 ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
670 hdr_off = PTR_DIFF(ptr, hdr);
671 ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
673 hdr_off = PTR_DIFF(ptr, hdr);
674 loads_init(phdr_loads, hdr_off);
675 *addr = (unsigned long long) hdr;
676 *size = (unsigned long long) hdr_off;
677 BUG_ON(elfcorehdr_size > alloc_size);
682 * Free ELF core header (new kernel)
684 void elfcorehdr_free(unsigned long long addr)
686 kfree((void *)(unsigned long)addr);
690 * Read from ELF header
692 ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
694 void *src = (void *)(unsigned long)*ppos;
696 memcpy(buf, src, count);
702 * Read from ELF notes data
704 ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
706 void *src = (void *)(unsigned long)*ppos;
708 memcpy(buf, src, count);