diff options
Diffstat (limited to 'arch/s390/kernel/crash_dump.c')
-rw-r--r-- | arch/s390/kernel/crash_dump.c | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c new file mode 100644 index 000000000..c13b1455e --- /dev/null +++ b/arch/s390/kernel/crash_dump.c @@ -0,0 +1,652 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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/init.h> +#include <linux/mm.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/memblock.h> +#include <linux/elf.h> +#include <linux/uio.h> +#include <asm/asm-offsets.h> +#include <asm/os_info.h> +#include <asm/elf.h> +#include <asm/ipl.h> +#include <asm/sclp.h> +#include <asm/maccess.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)))) + +static struct memblock_region oldmem_region; + +static struct memblock_type oldmem_type = { + .cnt = 1, + .max = 1, + .total_size = 0, + .regions = &oldmem_region, + .name = "oldmem", +}; + +struct save_area { + struct list_head list; + u64 psw[2]; + u64 ctrs[16]; + u64 gprs[16]; + u32 acrs[16]; + u64 fprs[16]; + u32 fpc; + u32 prefix; + u32 todpreg; + u64 timer; + u64 todcmp; + u64 vxrs_low[16]; + __vector128 vxrs_high[16]; +}; + +static LIST_HEAD(dump_save_areas); + +/* + * Allocate a save area + */ +struct save_area * __init save_area_alloc(bool is_boot_cpu) +{ + struct save_area *sa; + + sa = memblock_alloc(sizeof(*sa), 8); + if (!sa) + return NULL; + + if (is_boot_cpu) + list_add(&sa->list, &dump_save_areas); + else + list_add_tail(&sa->list, &dump_save_areas); + return sa; +} + +/* + * Return the address of the save area for the boot CPU + */ +struct save_area * __init save_area_boot_cpu(void) +{ + return list_first_entry_or_null(&dump_save_areas, struct save_area, list); +} + +/* + * Copy CPU registers into the save area + */ +void __init save_area_add_regs(struct save_area *sa, void *regs) +{ + struct lowcore *lc; + + lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA); + memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw)); + memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs)); + memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs)); + memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs)); + memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs)); + memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc)); + memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix)); + memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg)); + memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer)); + memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp)); +} + +/* + * Copy vector registers into the save area + */ +void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs) +{ + int i; + + /* Copy lower halves of vector registers 0-15 */ + for (i = 0; i < 16; i++) + memcpy(&sa->vxrs_low[i], &vxrs[i].u[2], 8); + /* Copy vector registers 16-31 */ + memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128)); +} + +static size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count) +{ + size_t len, copied, res = 0; + + while (count) { + if (!oldmem_data.start && src < sclp.hsa_size) { + /* Copy from zfcp/nvme dump HSA area */ + len = min(count, sclp.hsa_size - src); + copied = memcpy_hsa_iter(iter, src, len); + } else { + /* Check for swapped kdump oldmem areas */ + if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) { + src -= oldmem_data.start; + len = min(count, oldmem_data.size - src); + } else if (oldmem_data.start && src < oldmem_data.size) { + len = min(count, oldmem_data.size - src); + src += oldmem_data.start; + } else { + len = count; + } + copied = memcpy_real_iter(iter, src, len); + } + count -= copied; + src += copied; + res += copied; + if (copied < len) + break; + } + return res; +} + +int copy_oldmem_kernel(void *dst, unsigned long src, size_t count) +{ + struct iov_iter iter; + struct kvec kvec; + + kvec.iov_base = dst; + kvec.iov_len = count; + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count); + if (copy_oldmem_iter(&iter, src, count) < count) + return -EFAULT; + return 0; +} + +/* + * Copy one page from "oldmem" + */ +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize, + unsigned long offset) +{ + unsigned long src; + + src = pfn_to_phys(pfn) + offset; + return copy_oldmem_iter(iter, src, csize); +} + +/* + * Remap "oldmem" for kdump + * + * For the kdump reserved memory this functions performs a swap operation: + * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] + */ +static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma, + unsigned long from, unsigned long pfn, + unsigned long size, pgprot_t prot) +{ + unsigned long size_old; + int rc; + + if (pfn < oldmem_data.size >> PAGE_SHIFT) { + size_old = min(size, oldmem_data.size - (pfn << PAGE_SHIFT)); + rc = remap_pfn_range(vma, from, + pfn + (oldmem_data.start >> PAGE_SHIFT), + size_old, prot); + if (rc || size == size_old) + return rc; + size -= size_old; + from += size_old; + pfn += size_old >> PAGE_SHIFT; + } + return remap_pfn_range(vma, from, pfn, size, prot); +} + +/* + * Remap "oldmem" for zfcp/nvme dump + * + * We only map available memory above HSA size. Memory below HSA size + * is read on demand using the copy_oldmem_page() function. + */ +static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma, + unsigned long from, + unsigned long pfn, + unsigned long size, pgprot_t prot) +{ + unsigned long hsa_end = sclp.hsa_size; + unsigned long size_hsa; + + if (pfn < hsa_end >> PAGE_SHIFT) { + size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT)); + if (size == size_hsa) + return 0; + size -= size_hsa; + from += size_hsa; + pfn += size_hsa >> PAGE_SHIFT; + } + return remap_pfn_range(vma, from, pfn, size, prot); +} + +/* + * Remap "oldmem" for kdump or zfcp/nvme dump + */ +int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from, + unsigned long pfn, unsigned long size, pgprot_t prot) +{ + if (oldmem_data.start) + return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot); + else + return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size, + prot); +} + +static const char *nt_name(Elf64_Word type) +{ + const char *name = "LINUX"; + + if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG) + name = KEXEC_CORE_NOTE_NAME; + return name; +} + +/* + * Initialize ELF note + */ +static void *nt_init_name(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); +} + +static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len) +{ + return nt_init_name(buf, type, desc, d_len, nt_name(type)); +} + +/* + * Calculate the size of ELF note + */ +static size_t nt_size_name(int d_len, const char *name) +{ + size_t size; + + size = sizeof(Elf64_Nhdr); + size += roundup(strlen(name) + 1, 4); + size += roundup(d_len, 4); + + return size; +} + +static inline size_t nt_size(Elf64_Word type, int d_len) +{ + return nt_size_name(d_len, nt_name(type)); +} + +/* + * Fill ELF notes for one CPU with save area registers + */ +static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa) +{ + struct elf_prstatus nt_prstatus; + elf_fpregset_t nt_fpregset; + + /* Prepare prstatus note */ + memset(&nt_prstatus, 0, sizeof(nt_prstatus)); + memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs)); + memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw)); + memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs)); + nt_prstatus.common.pr_pid = cpu; + /* Prepare fpregset (floating point) note */ + memset(&nt_fpregset, 0, sizeof(nt_fpregset)); + memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc)); + memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs)); + /* Create ELF notes for the CPU */ + ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus)); + ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset)); + ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer)); + ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp)); + ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg)); + ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs)); + ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix)); + if (MACHINE_HAS_VX) { + ptr = nt_init(ptr, NT_S390_VXRS_HIGH, + &sa->vxrs_high, sizeof(sa->vxrs_high)); + ptr = nt_init(ptr, NT_S390_VXRS_LOW, + &sa->vxrs_low, sizeof(sa->vxrs_low)); + } + return ptr; +} + +/* + * Calculate size of ELF notes per cpu + */ +static size_t get_cpu_elf_notes_size(void) +{ + struct save_area *sa = NULL; + size_t size; + + size = nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus)); + size += nt_size(NT_PRFPREG, sizeof(elf_fpregset_t)); + size += nt_size(NT_S390_TIMER, sizeof(sa->timer)); + size += nt_size(NT_S390_TODCMP, sizeof(sa->todcmp)); + size += nt_size(NT_S390_TODPREG, sizeof(sa->todpreg)); + size += nt_size(NT_S390_CTRS, sizeof(sa->ctrs)); + size += nt_size(NT_S390_PREFIX, sizeof(sa->prefix)); + if (MACHINE_HAS_VX) { + size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high)); + size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low)); + } + + return size; +} + +/* + * 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)); +} + +/* + * Get vmcoreinfo using lowcore->vmcore_info (new kernel) + */ +static void *get_vmcoreinfo_old(unsigned long *size) +{ + char nt_name[11], *vmcoreinfo; + unsigned long addr; + Elf64_Nhdr note; + + if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr))) + return NULL; + memset(nt_name, 0, sizeof(nt_name)); + if (copy_oldmem_kernel(¬e, addr, sizeof(note))) + return NULL; + if (copy_oldmem_kernel(nt_name, addr + sizeof(note), + sizeof(nt_name) - 1)) + return NULL; + if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0) + return NULL; + vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL); + if (!vmcoreinfo) + return NULL; + if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) { + kfree(vmcoreinfo); + return NULL; + } + *size = note.n_descsz; + return vmcoreinfo; +} + +/* + * Initialize vmcoreinfo note (new kernel) + */ +static void *nt_vmcoreinfo(void *ptr) +{ + const char *name = VMCOREINFO_NOTE_NAME; + unsigned long size; + void *vmcoreinfo; + + vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); + if (vmcoreinfo) + return nt_init_name(ptr, 0, vmcoreinfo, size, name); + + vmcoreinfo = get_vmcoreinfo_old(&size); + if (!vmcoreinfo) + return ptr; + ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name); + kfree(vmcoreinfo); + return ptr; +} + +static size_t nt_vmcoreinfo_size(void) +{ + const char *name = VMCOREINFO_NOTE_NAME; + unsigned long size; + void *vmcoreinfo; + + vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); + if (vmcoreinfo) + return nt_size_name(size, name); + + vmcoreinfo = get_vmcoreinfo_old(&size); + if (!vmcoreinfo) + return 0; + + kfree(vmcoreinfo); + return nt_size_name(size, name); +} + +/* + * Initialize final note (needed for /proc/vmcore code) + */ +static void *nt_final(void *ptr) +{ + Elf64_Nhdr *note; + + note = (Elf64_Nhdr *) ptr; + note->n_namesz = 0; + note->n_descsz = 0; + note->n_type = 0; + return PTR_ADD(ptr, sizeof(Elf64_Nhdr)); +} + +/* + * 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) +{ + struct save_area *sa; + int cpus = 0; + + list_for_each_entry(sa, &dump_save_areas, list) + if (sa->prefix != 0) + cpus++; + return cpus; +} + +/* + * Return memory chunk count for ELF header (new kernel) + */ +static int get_mem_chunk_cnt(void) +{ + int cnt = 0; + u64 idx; + + for_each_physmem_range(idx, &oldmem_type, NULL, NULL) + cnt++; + return cnt; +} + +/* + * Initialize ELF loads (new kernel) + */ +static void loads_init(Elf64_Phdr *phdr, u64 loads_offset) +{ + phys_addr_t start, end; + u64 idx; + + for_each_physmem_range(idx, &oldmem_type, &start, &end) { + phdr->p_filesz = end - start; + phdr->p_type = PT_LOAD; + phdr->p_offset = start; + phdr->p_vaddr = start; + phdr->p_paddr = start; + phdr->p_memsz = end - start; + phdr->p_flags = PF_R | PF_W | PF_X; + phdr->p_align = PAGE_SIZE; + phdr++; + } +} + +/* + * 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 cpu; + + ptr = nt_prpsinfo(ptr); + + cpu = 1; + list_for_each_entry(sa, &dump_save_areas, list) + if (sa->prefix != 0) + ptr = fill_cpu_elf_notes(ptr, cpu++, sa); + ptr = nt_vmcoreinfo(ptr); + ptr = nt_final(ptr); + memset(phdr, 0, sizeof(*phdr)); + phdr->p_type = PT_NOTE; + phdr->p_offset = notes_offset; + phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start); + phdr->p_memsz = phdr->p_filesz; + return ptr; +} + +static size_t get_elfcorehdr_size(int mem_chunk_cnt) +{ + size_t size; + + size = sizeof(Elf64_Ehdr); + /* PT_NOTES */ + size += sizeof(Elf64_Phdr); + /* nt_prpsinfo */ + size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo)); + /* regsets */ + size += get_cpu_cnt() * get_cpu_elf_notes_size(); + /* nt_vmcoreinfo */ + size += nt_vmcoreinfo_size(); + /* nt_final */ + size += sizeof(Elf64_Nhdr); + /* PT_LOADS */ + size += mem_chunk_cnt * sizeof(Elf64_Phdr); + + return size; +} + +/* + * Create ELF core header (new kernel) + */ +int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size) +{ + Elf64_Phdr *phdr_notes, *phdr_loads; + int mem_chunk_cnt; + void *ptr, *hdr; + u32 alloc_size; + u64 hdr_off; + + /* If we are not in kdump or zfcp/nvme dump mode return */ + if (!oldmem_data.start && !is_ipl_type_dump()) + return 0; + /* If we cannot get HSA size for zfcp/nvme dump return error */ + if (is_ipl_type_dump() && !sclp.hsa_size) + return -ENODEV; + + /* For kdump, exclude previous crashkernel memory */ + if (oldmem_data.start) { + oldmem_region.base = oldmem_data.start; + oldmem_region.size = oldmem_data.size; + oldmem_type.total_size = oldmem_data.size; + } + + mem_chunk_cnt = get_mem_chunk_cnt(); + + alloc_size = get_elfcorehdr_size(mem_chunk_cnt); + + hdr = kzalloc(alloc_size, GFP_KERNEL); + + /* Without elfcorehdr /proc/vmcore cannot be created. Thus creating + * a dump with this crash kernel will fail. Panic now to allow other + * dump mechanisms to take over. + */ + if (!hdr) + panic("s390 kdump allocating elfcorehdr failed"); + + /* 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, hdr_off); + *addr = (unsigned long long) hdr; + *size = (unsigned long long) hdr_off; + BUG_ON(elfcorehdr_size > alloc_size); + return 0; +} + +/* + * Free ELF core header (new kernel) + */ +void elfcorehdr_free(unsigned long long addr) +{ + kfree((void *)(unsigned long)addr); +} + +/* + * Read from ELF header + */ +ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) +{ + void *src = (void *)(unsigned long)*ppos; + + memcpy(buf, src, count); + *ppos += count; + return count; +} + +/* + * Read from ELF notes data + */ +ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos) +{ + void *src = (void *)(unsigned long)*ppos; + + memcpy(buf, src, count); + *ppos += count; + return count; +} |