// 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);
}
