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// 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[] = {
NULL,
};
/*
* 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);
}
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