diff options
Diffstat (limited to 'arch/s390/kernel/machine_kexec_file.c')
| -rw-r--r-- | arch/s390/kernel/machine_kexec_file.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c new file mode 100644 index 000000000000..f413f57f8d20 --- /dev/null +++ b/arch/s390/kernel/machine_kexec_file.c @@ -0,0 +1,245 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * s390 code for kexec_file_load system call + * + * Copyright IBM Corp. 2018 + * + * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> + */ + +#include <linux/elf.h> +#include <linux/kexec.h> +#include <asm/setup.h> + +const struct kexec_file_ops * const kexec_file_loaders[] = { + &s390_kexec_elf_ops, + &s390_kexec_image_ops, + NULL, +}; + +int *kexec_file_update_kernel(struct kimage *image, + struct s390_load_data *data) +{ + unsigned long *loc; + + if (image->cmdline_buf_len >= ARCH_COMMAND_LINE_SIZE) + return ERR_PTR(-EINVAL); + + if (image->cmdline_buf_len) + memcpy(data->kernel_buf + COMMAND_LINE_OFFSET, + image->cmdline_buf, image->cmdline_buf_len); + + if (image->type == KEXEC_TYPE_CRASH) { + loc = (unsigned long *)(data->kernel_buf + OLDMEM_BASE_OFFSET); + *loc = crashk_res.start; + + loc = (unsigned long *)(data->kernel_buf + OLDMEM_SIZE_OFFSET); + *loc = crashk_res.end - crashk_res.start + 1; + } + + if (image->initrd_buf) { + loc = (unsigned long *)(data->kernel_buf + INITRD_START_OFFSET); + *loc = data->initrd_load_addr; + + loc = (unsigned long *)(data->kernel_buf + INITRD_SIZE_OFFSET); + *loc = image->initrd_buf_len; + } + + return NULL; +} + +static int kexec_file_update_purgatory(struct kimage *image) +{ + u64 entry, type; + int ret; + + if (image->type == KEXEC_TYPE_CRASH) { + entry = STARTUP_KDUMP_OFFSET; + type = KEXEC_TYPE_CRASH; + } else { + entry = STARTUP_NORMAL_OFFSET; + type = KEXEC_TYPE_DEFAULT; + } + + ret = kexec_purgatory_get_set_symbol(image, "kernel_entry", &entry, + sizeof(entry), false); + if (ret) + return ret; + + ret = kexec_purgatory_get_set_symbol(image, "kernel_type", &type, + sizeof(type), false); + if (ret) + return ret; + + if (image->type == KEXEC_TYPE_CRASH) { + u64 crash_size; + + ret = kexec_purgatory_get_set_symbol(image, "crash_start", + &crashk_res.start, + sizeof(crashk_res.start), + false); + if (ret) + return ret; + + crash_size = crashk_res.end - crashk_res.start + 1; + ret = kexec_purgatory_get_set_symbol(image, "crash_size", + &crash_size, + sizeof(crash_size), + false); + } + return ret; +} + +int kexec_file_add_purgatory(struct kimage *image, struct s390_load_data *data) +{ + struct kexec_buf buf; + int ret; + + buf.image = image; + + data->memsz = ALIGN(data->memsz, PAGE_SIZE); + buf.mem = data->memsz; + if (image->type == KEXEC_TYPE_CRASH) + buf.mem += crashk_res.start; + + ret = kexec_load_purgatory(image, &buf); + if (ret) + return ret; + + ret = kexec_file_update_purgatory(image); + return ret; +} + +int kexec_file_add_initrd(struct kimage *image, struct s390_load_data *data, + char *initrd, unsigned long initrd_len) +{ + struct kexec_buf buf; + int ret; + + buf.image = image; + + buf.buffer = initrd; + buf.bufsz = initrd_len; + + data->memsz = ALIGN(data->memsz, PAGE_SIZE); + buf.mem = data->memsz; + if (image->type == KEXEC_TYPE_CRASH) + buf.mem += crashk_res.start; + buf.memsz = buf.bufsz; + + data->initrd_load_addr = buf.mem; + data->memsz += buf.memsz; + + ret = kexec_add_buffer(&buf); + return ret; +} + +/* + * The kernel is loaded to a fixed location. Turn off kexec_locate_mem_hole + * and provide kbuf->mem by hand. + */ +int arch_kexec_walk_mem(struct kexec_buf *kbuf, + int (*func)(struct resource *, void *)) +{ + return 1; +} + +int arch_kexec_apply_relocations_add(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab) +{ + Elf_Rela *relas; + int i; + + relas = (void *)pi->ehdr + relsec->sh_offset; + + for (i = 0; i < relsec->sh_size / sizeof(*relas); i++) { + const Elf_Sym *sym; /* symbol to relocate */ + unsigned long addr; /* final location after relocation */ + unsigned long val; /* relocated symbol value */ + void *loc; /* tmp location to modify */ + + sym = (void *)pi->ehdr + symtab->sh_offset; + sym += ELF64_R_SYM(relas[i].r_info); + + if (sym->st_shndx == SHN_UNDEF) + return -ENOEXEC; + + if (sym->st_shndx == SHN_COMMON) + return -ENOEXEC; + + if (sym->st_shndx >= pi->ehdr->e_shnum && + sym->st_shndx != SHN_ABS) + return -ENOEXEC; + + loc = pi->purgatory_buf; + loc += section->sh_offset; + loc += relas[i].r_offset; + + val = sym->st_value; + if (sym->st_shndx != SHN_ABS) + val += pi->sechdrs[sym->st_shndx].sh_addr; + val += relas[i].r_addend; + + addr = section->sh_addr + relas[i].r_offset; + + switch (ELF64_R_TYPE(relas[i].r_info)) { + case R_390_8: /* Direct 8 bit. */ + *(u8 *)loc = val; + break; + case R_390_12: /* Direct 12 bit. */ + *(u16 *)loc &= 0xf000; + *(u16 *)loc |= val & 0xfff; + break; + case R_390_16: /* Direct 16 bit. */ + *(u16 *)loc = val; + break; + case R_390_20: /* Direct 20 bit. */ + *(u32 *)loc &= 0xf00000ff; + *(u32 *)loc |= (val & 0xfff) << 16; /* DL */ + *(u32 *)loc |= (val & 0xff000) >> 4; /* DH */ + break; + case R_390_32: /* Direct 32 bit. */ + *(u32 *)loc = val; + break; + case R_390_64: /* Direct 64 bit. */ + *(u64 *)loc = val; + break; + case R_390_PC16: /* PC relative 16 bit. */ + *(u16 *)loc = (val - addr); + break; + case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ + *(u16 *)loc = (val - addr) >> 1; + break; + case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ + *(u32 *)loc = (val - addr) >> 1; + break; + case R_390_PC32: /* PC relative 32 bit. */ + *(u32 *)loc = (val - addr); + break; + case R_390_PC64: /* PC relative 64 bit. */ + *(u64 *)loc = (val - addr); + break; + default: + break; + } + } + return 0; +} + +int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, + unsigned long buf_len) +{ + /* A kernel must be at least large enough to contain head.S. During + * load memory in head.S will be accessed, e.g. to register the next + * command line. If the next kernel were smaller the current kernel + * will panic at load. + * + * 0x11000 = sizeof(head.S) + */ + if (buf_len < 0x11000) + return -ENOEXEC; + + return kexec_image_probe_default(image, buf, buf_len); +} |