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#include <stdio.h>
#include <elf.h>
#include <string.h>
#include "../../kexec.h"
#include "../../kexec-elf.h"
#include "kexec-ppc64.h"
int machine_verify_elf_rel(struct mem_ehdr *ehdr)
{
if (ehdr->ei_class != ELFCLASS64) {
return 0;
}
if (ehdr->e_machine != EM_PPC64) {
return 0;
}
return 1;
}
static struct mem_shdr *toc_section(const struct mem_ehdr *ehdr)
{
struct mem_shdr *shdr, *shdr_end;
unsigned char *strtab;
strtab = (unsigned char *)ehdr->e_shdr[ehdr->e_shstrndx].sh_data;
shdr_end = &ehdr->e_shdr[ehdr->e_shnum];
for (shdr = ehdr->e_shdr; shdr != shdr_end; shdr++) {
if (shdr->sh_size &&
strcmp((char *)&strtab[shdr->sh_name], ".toc") == 0) {
return shdr;
}
}
return NULL;
}
/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
gives the value maximum span in an instruction which uses a signed
offset) */
unsigned long my_r2(const struct mem_ehdr *ehdr)
{
struct mem_shdr *shdr;
shdr = toc_section(ehdr);
if (!shdr) {
die("TOC reloc without a toc section?");
}
return shdr->sh_addr + 0x8000;
}
static void do_relative_toc(unsigned long value, uint16_t *location,
unsigned long mask, int complain_signed)
{
if (complain_signed && (value + 0x8000 > 0xffff)) {
die("TOC16 relocation overflows (%lu)\n", value);
}
if ((~mask & 0xffff) & value) {
die("bad TOC16 relocation (%lu)\n", value);
}
*location = (*location & ~mask) | (value & mask);
}
void machine_apply_elf_rel(struct mem_ehdr *ehdr, unsigned long r_type,
void *location, unsigned long address, unsigned long value)
{
switch(r_type) {
case R_PPC64_ADDR32:
/* Simply set it */
*(uint32_t *)location = value;
break;
case R_PPC64_ADDR64:
case R_PPC64_REL64:
/* Simply set it */
*(uint64_t *)location = value;
break;
case R_PPC64_REL32:
*(uint32_t *)location = value - (uint32_t)(uint64_t)location;
break;
case R_PPC64_TOC:
*(uint64_t *)location = my_r2(ehdr);
break;
case R_PPC64_TOC16:
do_relative_toc(value - my_r2(ehdr), location, 0xffff, 1);
break;
case R_PPC64_TOC16_DS:
do_relative_toc(value - my_r2(ehdr), location, 0xfffc, 1);
break;
case R_PPC64_TOC16_LO:
do_relative_toc(value - my_r2(ehdr), location, 0xffff, 0);
break;
case R_PPC64_TOC16_LO_DS:
do_relative_toc(value - my_r2(ehdr), location, 0xfffc, 0);
break;
case R_PPC64_TOC16_HI:
do_relative_toc((value - my_r2(ehdr)) >> 16, location,
0xffff, 0);
break;
case R_PPC64_TOC16_HA:
do_relative_toc((value - my_r2(ehdr) + 0x8000) >> 16, location,
0xffff, 0);
break;
case R_PPC64_REL24:
/* Convert value to relative */
value -= address;
if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0) {
die("REL24 %li out of range!\n", (long int)value);
}
/* Only replace bits 2 through 26 */
*(uint32_t *)location = (*(uint32_t *)location & ~0x03fffffc) |
(value & 0x03fffffc);
break;
case R_PPC64_ADDR16_LO:
*(uint16_t *)location = value & 0xffff;
break;
case R_PPC64_ADDR16_HI:
*(uint16_t *)location = (value >> 16) & 0xffff;
break;
case R_PPC64_ADDR16_HA:
*(uint16_t *)location = (((value + 0x8000) >> 16) & 0xffff);
break;
case R_PPC64_ADDR16_HIGHER:
*(uint16_t *)location = (((uint64_t)value >> 32) & 0xffff);
break;
case R_PPC64_ADDR16_HIGHEST:
*(uint16_t *)location = (((uint64_t)value >> 48) & 0xffff);
break;
/* R_PPC64_REL16_HA and R_PPC64_REL16_LO are handled to support
* ABIv2 r2 assignment based on r12 for PIC executable.
* Here address is know so replace
* 0: addis 2,12,.TOC.-0b@ha
* addi 2,2,.TOC.-0b@l
* by
* lis 2,.TOC.@ha
* addi 2,2,.TOC.@l
*/
case R_PPC64_REL16_HA:
/* check that we are dealing with the addis 2,12 instruction */
if (((*(uint32_t*)location) & 0xffff0000) != 0x3c4c0000)
die("Unexpected instruction for R_PPC64_REL16_HA");
value += my_r2(ehdr);
/* replacing by lis 2 */
*(uint32_t *)location = 0x3c400000 + ((value >> 16) & 0xffff);
break;
case R_PPC64_REL16_LO:
/* check that we are dealing with the addi 2,2 instruction */
if (((*(uint32_t*)location) & 0xffff0000) != 0x38420000)
die("Unexpected instruction for R_PPC64_REL16_LO");
value += my_r2(ehdr) - 4;
*(uint16_t *)location = value & 0xffff;
break;
default:
die("Unknown rela relocation: %lu\n", r_type);
break;
}
}
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