| /* |
| * S390 kdump implementation |
| * |
| * Copyright IBM Corp. 2011 |
| * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com> |
| */ |
| |
| #include <linux/crash_dump.h> |
| #include <asm/lowcore.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/gfp.h> |
| #include <linux/slab.h> |
| #include <linux/bootmem.h> |
| #include <linux/elf.h> |
| #include <asm/ipl.h> |
| #include <asm/os_info.h> |
| |
| #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y))) |
| #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y))) |
| #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y)))) |
| |
| /* |
| * Copy one page from "oldmem" |
| * |
| * For the kdump reserved memory this functions performs a swap operation: |
| * - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE]. |
| * - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] |
| */ |
| ssize_t copy_oldmem_page(unsigned long pfn, char *buf, |
| size_t csize, unsigned long offset, int userbuf) |
| { |
| unsigned long src; |
| |
| if (!csize) |
| return 0; |
| |
| src = (pfn << PAGE_SHIFT) + offset; |
| if (src < OLDMEM_SIZE) |
| src += OLDMEM_BASE; |
| else if (src > OLDMEM_BASE && |
| src < OLDMEM_BASE + OLDMEM_SIZE) |
| src -= OLDMEM_BASE; |
| if (userbuf) |
| copy_to_user_real((void __force __user *) buf, (void *) src, |
| csize); |
| else |
| memcpy_real(buf, (void *) src, csize); |
| return csize; |
| } |
| |
| /* |
| * Copy memory from old kernel |
| */ |
| int copy_from_oldmem(void *dest, void *src, size_t count) |
| { |
| unsigned long copied = 0; |
| int rc; |
| |
| if ((unsigned long) src < OLDMEM_SIZE) { |
| copied = min(count, OLDMEM_SIZE - (unsigned long) src); |
| rc = memcpy_real(dest, src + OLDMEM_BASE, copied); |
| if (rc) |
| return rc; |
| } |
| return memcpy_real(dest + copied, src + copied, count - copied); |
| } |
| |
| /* |
| * Alloc memory and panic in case of ENOMEM |
| */ |
| static void *kzalloc_panic(int len) |
| { |
| void *rc; |
| |
| rc = kzalloc(len, GFP_KERNEL); |
| if (!rc) |
| panic("s390 kdump kzalloc (%d) failed", len); |
| return rc; |
| } |
| |
| /* |
| * Get memory layout and create hole for oldmem |
| */ |
| static struct mem_chunk *get_memory_layout(void) |
| { |
| struct mem_chunk *chunk_array; |
| |
| chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk)); |
| detect_memory_layout(chunk_array); |
| create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE, CHUNK_CRASHK); |
| return chunk_array; |
| } |
| |
| /* |
| * Initialize ELF note |
| */ |
| static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len, |
| const char *name) |
| { |
| Elf64_Nhdr *note; |
| u64 len; |
| |
| note = (Elf64_Nhdr *)buf; |
| note->n_namesz = strlen(name) + 1; |
| note->n_descsz = d_len; |
| note->n_type = type; |
| len = sizeof(Elf64_Nhdr); |
| |
| memcpy(buf + len, name, note->n_namesz); |
| len = roundup(len + note->n_namesz, 4); |
| |
| memcpy(buf + len, desc, note->n_descsz); |
| len = roundup(len + note->n_descsz, 4); |
| |
| return PTR_ADD(buf, len); |
| } |
| |
| /* |
| * Initialize prstatus note |
| */ |
| static void *nt_prstatus(void *ptr, struct save_area *sa) |
| { |
| struct elf_prstatus nt_prstatus; |
| static int cpu_nr = 1; |
| |
| memset(&nt_prstatus, 0, sizeof(nt_prstatus)); |
| memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs)); |
| memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw)); |
| memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs)); |
| nt_prstatus.pr_pid = cpu_nr; |
| cpu_nr++; |
| |
| return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus), |
| "CORE"); |
| } |
| |
| /* |
| * Initialize fpregset (floating point) note |
| */ |
| static void *nt_fpregset(void *ptr, struct save_area *sa) |
| { |
| elf_fpregset_t nt_fpregset; |
| |
| memset(&nt_fpregset, 0, sizeof(nt_fpregset)); |
| memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg)); |
| memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs)); |
| |
| return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset), |
| "CORE"); |
| } |
| |
| /* |
| * Initialize timer note |
| */ |
| static void *nt_s390_timer(void *ptr, struct save_area *sa) |
| { |
| return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer), |
| KEXEC_CORE_NOTE_NAME); |
| } |
| |
| /* |
| * Initialize TOD clock comparator note |
| */ |
| static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa) |
| { |
| return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp, |
| sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME); |
| } |
| |
| /* |
| * Initialize TOD programmable register note |
| */ |
| static void *nt_s390_tod_preg(void *ptr, struct save_area *sa) |
| { |
| return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg, |
| sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME); |
| } |
| |
| /* |
| * Initialize control register note |
| */ |
| static void *nt_s390_ctrs(void *ptr, struct save_area *sa) |
| { |
| return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs, |
| sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME); |
| } |
| |
| /* |
| * Initialize prefix register note |
| */ |
| static void *nt_s390_prefix(void *ptr, struct save_area *sa) |
| { |
| return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg, |
| sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME); |
| } |
| |
| /* |
| * Fill ELF notes for one CPU with save area registers |
| */ |
| void *fill_cpu_elf_notes(void *ptr, struct save_area *sa) |
| { |
| ptr = nt_prstatus(ptr, sa); |
| ptr = nt_fpregset(ptr, sa); |
| ptr = nt_s390_timer(ptr, sa); |
| ptr = nt_s390_tod_cmp(ptr, sa); |
| ptr = nt_s390_tod_preg(ptr, sa); |
| ptr = nt_s390_ctrs(ptr, sa); |
| ptr = nt_s390_prefix(ptr, sa); |
| return ptr; |
| } |
| |
| /* |
| * Initialize prpsinfo note (new kernel) |
| */ |
| static void *nt_prpsinfo(void *ptr) |
| { |
| struct elf_prpsinfo prpsinfo; |
| |
| memset(&prpsinfo, 0, sizeof(prpsinfo)); |
| prpsinfo.pr_sname = 'R'; |
| strcpy(prpsinfo.pr_fname, "vmlinux"); |
| return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo), |
| KEXEC_CORE_NOTE_NAME); |
| } |
| |
| /* |
| * Get vmcoreinfo using lowcore->vmcore_info (new kernel) |
| */ |
| static void *get_vmcoreinfo_old(unsigned long *size) |
| { |
| char nt_name[11], *vmcoreinfo; |
| Elf64_Nhdr note; |
| void *addr; |
| |
| if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr))) |
| return NULL; |
| memset(nt_name, 0, sizeof(nt_name)); |
| if (copy_from_oldmem(¬e, addr, sizeof(note))) |
| return NULL; |
| if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1)) |
| return NULL; |
| if (strcmp(nt_name, "VMCOREINFO") != 0) |
| return NULL; |
| vmcoreinfo = kzalloc_panic(note.n_descsz); |
| if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz)) |
| return NULL; |
| *size = note.n_descsz; |
| return vmcoreinfo; |
| } |
| |
| /* |
| * Initialize vmcoreinfo note (new kernel) |
| */ |
| static void *nt_vmcoreinfo(void *ptr) |
| { |
| unsigned long size; |
| void *vmcoreinfo; |
| |
| vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); |
| if (!vmcoreinfo) |
| vmcoreinfo = get_vmcoreinfo_old(&size); |
| if (!vmcoreinfo) |
| return ptr; |
| return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO"); |
| } |
| |
| /* |
| * Initialize ELF header (new kernel) |
| */ |
| static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt) |
| { |
| memset(ehdr, 0, sizeof(*ehdr)); |
| memcpy(ehdr->e_ident, ELFMAG, SELFMAG); |
| ehdr->e_ident[EI_CLASS] = ELFCLASS64; |
| ehdr->e_ident[EI_DATA] = ELFDATA2MSB; |
| ehdr->e_ident[EI_VERSION] = EV_CURRENT; |
| memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD); |
| ehdr->e_type = ET_CORE; |
| ehdr->e_machine = EM_S390; |
| ehdr->e_version = EV_CURRENT; |
| ehdr->e_phoff = sizeof(Elf64_Ehdr); |
| ehdr->e_ehsize = sizeof(Elf64_Ehdr); |
| ehdr->e_phentsize = sizeof(Elf64_Phdr); |
| ehdr->e_phnum = mem_chunk_cnt + 1; |
| return ehdr + 1; |
| } |
| |
| /* |
| * Return CPU count for ELF header (new kernel) |
| */ |
| static int get_cpu_cnt(void) |
| { |
| int i, cpus = 0; |
| |
| for (i = 0; zfcpdump_save_areas[i]; i++) { |
| if (zfcpdump_save_areas[i]->pref_reg == 0) |
| continue; |
| cpus++; |
| } |
| return cpus; |
| } |
| |
| /* |
| * Return memory chunk count for ELF header (new kernel) |
| */ |
| static int get_mem_chunk_cnt(void) |
| { |
| struct mem_chunk *chunk_array, *mem_chunk; |
| int i, cnt = 0; |
| |
| chunk_array = get_memory_layout(); |
| for (i = 0; i < MEMORY_CHUNKS; i++) { |
| mem_chunk = &chunk_array[i]; |
| if (chunk_array[i].type != CHUNK_READ_WRITE && |
| chunk_array[i].type != CHUNK_READ_ONLY) |
| continue; |
| if (mem_chunk->size == 0) |
| continue; |
| cnt++; |
| } |
| kfree(chunk_array); |
| return cnt; |
| } |
| |
| /* |
| * Relocate pointer in order to allow vmcore code access the data |
| */ |
| static inline unsigned long relocate(unsigned long addr) |
| { |
| return OLDMEM_BASE + addr; |
| } |
| |
| /* |
| * Initialize ELF loads (new kernel) |
| */ |
| static int loads_init(Elf64_Phdr *phdr, u64 loads_offset) |
| { |
| struct mem_chunk *chunk_array, *mem_chunk; |
| int i; |
| |
| chunk_array = get_memory_layout(); |
| for (i = 0; i < MEMORY_CHUNKS; i++) { |
| mem_chunk = &chunk_array[i]; |
| if (mem_chunk->size == 0) |
| break; |
| if (chunk_array[i].type != CHUNK_READ_WRITE && |
| chunk_array[i].type != CHUNK_READ_ONLY) |
| continue; |
| else |
| phdr->p_filesz = mem_chunk->size; |
| phdr->p_type = PT_LOAD; |
| phdr->p_offset = mem_chunk->addr; |
| phdr->p_vaddr = mem_chunk->addr; |
| phdr->p_paddr = mem_chunk->addr; |
| phdr->p_memsz = mem_chunk->size; |
| phdr->p_flags = PF_R | PF_W | PF_X; |
| phdr->p_align = PAGE_SIZE; |
| phdr++; |
| } |
| kfree(chunk_array); |
| return i; |
| } |
| |
| /* |
| * Initialize notes (new kernel) |
| */ |
| static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset) |
| { |
| struct save_area *sa; |
| void *ptr_start = ptr; |
| int i; |
| |
| ptr = nt_prpsinfo(ptr); |
| |
| for (i = 0; zfcpdump_save_areas[i]; i++) { |
| sa = zfcpdump_save_areas[i]; |
| if (sa->pref_reg == 0) |
| continue; |
| ptr = fill_cpu_elf_notes(ptr, sa); |
| } |
| ptr = nt_vmcoreinfo(ptr); |
| memset(phdr, 0, sizeof(*phdr)); |
| phdr->p_type = PT_NOTE; |
| phdr->p_offset = relocate(notes_offset); |
| phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start); |
| phdr->p_memsz = phdr->p_filesz; |
| return ptr; |
| } |
| |
| /* |
| * Create ELF core header (new kernel) |
| */ |
| static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) |
| { |
| Elf64_Phdr *phdr_notes, *phdr_loads; |
| int mem_chunk_cnt; |
| void *ptr, *hdr; |
| u32 alloc_size; |
| u64 hdr_off; |
| |
| mem_chunk_cnt = get_mem_chunk_cnt(); |
| |
| alloc_size = 0x1000 + get_cpu_cnt() * 0x300 + |
| mem_chunk_cnt * sizeof(Elf64_Phdr); |
| hdr = kzalloc_panic(alloc_size); |
| /* Init elf header */ |
| ptr = ehdr_init(hdr, mem_chunk_cnt); |
| /* Init program headers */ |
| phdr_notes = ptr; |
| ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr)); |
| phdr_loads = ptr; |
| ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt); |
| /* Init notes */ |
| hdr_off = PTR_DIFF(ptr, hdr); |
| ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off); |
| /* Init loads */ |
| hdr_off = PTR_DIFF(ptr, hdr); |
| loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off); |
| *elfcorebuf_sz = hdr_off; |
| *elfcorebuf = (void *) relocate((unsigned long) hdr); |
| BUG_ON(*elfcorebuf_sz > alloc_size); |
| } |
| |
| /* |
| * Create kdump ELF core header in new kernel, if it has not been passed via |
| * the "elfcorehdr" kernel parameter |
| */ |
| static int setup_kdump_elfcorehdr(void) |
| { |
| size_t elfcorebuf_sz; |
| char *elfcorebuf; |
| |
| if (!OLDMEM_BASE || is_kdump_kernel()) |
| return -EINVAL; |
| s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz); |
| elfcorehdr_addr = (unsigned long long) elfcorebuf; |
| elfcorehdr_size = elfcorebuf_sz; |
| return 0; |
| } |
| |
| subsys_initcall(setup_kdump_elfcorehdr); |