diff options
Diffstat (limited to 'kexec/arch/ppc64/kexec-elf-rel-ppc64.c')
| -rw-r--r-- | kexec/arch/ppc64/kexec-elf-rel-ppc64.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/kexec/arch/ppc64/kexec-elf-rel-ppc64.c b/kexec/arch/ppc64/kexec-elf-rel-ppc64.c new file mode 100644 index 0000000..51b1354 --- /dev/null +++ b/kexec/arch/ppc64/kexec-elf-rel-ppc64.c @@ -0,0 +1,204 @@ +#include <stdio.h> +#include <elf.h> +#include <string.h> +#include "../../kexec.h" +#include "../../kexec-elf.h" +#include "kexec-ppc64.h" + +#if defined(_CALL_ELF) && _CALL_ELF == 2 +#define STO_PPC64_LOCAL_BIT 5 +#define STO_PPC64_LOCAL_MASK (7 << STO_PPC64_LOCAL_BIT) +#define PPC64_LOCAL_ENTRY_OFFSET(other) \ + (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2) + +static unsigned int local_entry_offset(struct mem_sym *sym) +{ + /* If this symbol has a local entry point, use it. */ + return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other); +} +#else +static unsigned int local_entry_offset(struct mem_sym *UNUSED(sym)) +{ + return 0; +} +#endif + +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; +} + +int machine_verify_elf_rel(struct mem_ehdr *ehdr) +{ + struct mem_shdr *toc; + + if (ehdr->ei_class != ELFCLASS64) { + return 0; + } + if (ehdr->e_machine != EM_PPC64) { + return 0; + } + + /* Ensure .toc is sufficiently aligned. */ + toc = toc_section(ehdr); + if (toc && toc->sh_addralign < 256) + toc->sh_addralign = 256; + return 1; +} + +/* 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, struct mem_sym *sym, + 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)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: + value += local_entry_offset(sym); + /* 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; + } +} |