diff options
Diffstat (limited to 'grub-core/kern/mips/dl.c')
| -rw-r--r-- | grub-core/kern/mips/dl.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/grub-core/kern/mips/dl.c b/grub-core/kern/mips/dl.c new file mode 100644 index 0000000..5d7d299 --- /dev/null +++ b/grub-core/kern/mips/dl.c @@ -0,0 +1,274 @@ +/* dl-386.c - arch-dependent part of loadable module support */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2002,2005,2007,2009 Free Software Foundation, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/dl.h> +#include <grub/elf.h> +#include <grub/misc.h> +#include <grub/err.h> +#include <grub/cpu/types.h> +#include <grub/mm.h> +#include <grub/i18n.h> + +/* Dummy __gnu_local_gp. Resolved by linker. */ +static char __gnu_local_gp_dummy; +static char _gp_disp_dummy; + +/* Check if EHDR is a valid ELF header. */ +grub_err_t +grub_arch_dl_check_header (void *ehdr) +{ + Elf_Ehdr *e = ehdr; + + /* Check the magic numbers. */ +#ifdef GRUB_CPU_WORDS_BIGENDIAN + if (e->e_ident[EI_CLASS] != ELFCLASS32 + || e->e_ident[EI_DATA] != ELFDATA2MSB + || e->e_machine != EM_MIPS) +#else + if (e->e_ident[EI_CLASS] != ELFCLASS32 + || e->e_ident[EI_DATA] != ELFDATA2LSB + || e->e_machine != EM_MIPS) +#endif + return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-dependent ELF magic")); + + return GRUB_ERR_NONE; +} + +#pragma GCC diagnostic ignored "-Wcast-align" + +grub_err_t +grub_arch_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp, + grub_size_t *got) +{ + const Elf_Ehdr *e = ehdr; + const Elf_Shdr *s; + /* FIXME: suboptimal. */ + grub_size_t gp_size = 0; + unsigned i; + + *tramp = 0; + *got = 0; + + for (i = 0, s = (const Elf_Shdr *) ((const char *) e + e->e_shoff); + i < e->e_shnum; + i++, s = (const Elf_Shdr *) ((const char *) s + e->e_shentsize)) + if (s->sh_type == SHT_REL) + { + const Elf_Rel *rel, *max; + + for (rel = (const Elf_Rel *) ((const char *) e + s->sh_offset), + max = rel + s->sh_size / s->sh_entsize; + rel < max; + rel++) + switch (ELF_R_TYPE (rel->r_info)) + { + case R_MIPS_GOT16: + case R_MIPS_CALL16: + case R_MIPS_GPREL32: + gp_size += 4; + break; + } + } + + if (gp_size > 0x08000) + return grub_error (GRUB_ERR_OUT_OF_RANGE, "__gnu_local_gp is too big\n"); + + *got = gp_size; + + return GRUB_ERR_NONE; +} + +/* Relocate symbols. */ +grub_err_t +grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr, + Elf_Shdr *s, grub_dl_segment_t seg) +{ + grub_uint32_t gp0; + Elf_Ehdr *e = ehdr; + + if (!mod->reginfo) + { + unsigned i; + Elf_Shdr *ri; + + /* Find reginfo. */ + for (i = 0, ri = (Elf_Shdr *) ((char *) ehdr + e->e_shoff); + i < e->e_shnum; + i++, ri = (Elf_Shdr *) ((char *) ri + e->e_shentsize)) + if (ri->sh_type == SHT_MIPS_REGINFO) + break; + if (i == e->e_shnum) + return grub_error (GRUB_ERR_BAD_MODULE, "no reginfo found"); + mod->reginfo = (grub_uint32_t *)((char *) ehdr + ri->sh_offset); + } + + gp0 = mod->reginfo[5]; + Elf_Rel *rel, *max; + + for (rel = (Elf_Rel *) ((char *) e + s->sh_offset), + max = (Elf_Rel *) ((char *) rel + s->sh_size); + rel < max; + rel = (Elf_Rel *) ((char *) rel + s->sh_entsize)) + { + grub_uint8_t *addr; + Elf_Sym *sym; + grub_uint32_t sym_value; + + if (seg->size < rel->r_offset) + return grub_error (GRUB_ERR_BAD_MODULE, + "reloc offset is out of the segment"); + + addr = (grub_uint8_t *) ((char *) seg->addr + rel->r_offset); + sym = (Elf_Sym *) ((char *) mod->symtab + + mod->symsize * ELF_R_SYM (rel->r_info)); + sym_value = sym->st_value; + if (s->sh_type == SHT_RELA) + { + sym_value += ((Elf_Rela *) rel)->r_addend; + } + if (sym_value == (grub_addr_t) &__gnu_local_gp_dummy) + sym_value = (grub_addr_t) mod->got; + else if (sym_value == (grub_addr_t) &_gp_disp_dummy) + { + sym_value = (grub_addr_t) mod->got - (grub_addr_t) addr; + if (ELF_R_TYPE (rel->r_info) == R_MIPS_LO16) + /* ABI mandates +4 even if partner lui doesn't + immediately precede addiu. */ + sym_value += 4; + } + switch (ELF_R_TYPE (rel->r_info)) + { + case R_MIPS_HI16: + { + grub_uint32_t value; + Elf_Rel *rel2; + +#ifdef GRUB_CPU_WORDS_BIGENDIAN + addr += 2; +#endif + + /* Handle partner lo16 relocation. Lower part is + treated as signed. Hence add 0x8000 to compensate. + */ + value = (*(grub_uint16_t *) addr << 16) + + sym_value + 0x8000; + for (rel2 = rel + 1; rel2 < max; rel2++) + if (ELF_R_SYM (rel2->r_info) + == ELF_R_SYM (rel->r_info) + && ELF_R_TYPE (rel2->r_info) == R_MIPS_LO16) + { + value += *(grub_int16_t *) + ((char *) seg->addr + rel2->r_offset +#ifdef GRUB_CPU_WORDS_BIGENDIAN + + 2 +#endif + ); + break; + } + *(grub_uint16_t *) addr = (value >> 16) & 0xffff; + } + break; + case R_MIPS_LO16: +#ifdef GRUB_CPU_WORDS_BIGENDIAN + addr += 2; +#endif + *(grub_uint16_t *) addr += sym_value & 0xffff; + break; + case R_MIPS_32: + *(grub_uint32_t *) addr += sym_value; + break; + case R_MIPS_GPREL32: + *(grub_uint32_t *) addr = sym_value + + *(grub_uint32_t *) addr + gp0 - (grub_uint32_t)mod->got; + break; + + case R_MIPS_26: + { + grub_uint32_t value; + grub_uint32_t raw; + raw = (*(grub_uint32_t *) addr) & 0x3ffffff; + value = raw << 2; + value += sym_value; + raw = (value >> 2) & 0x3ffffff; + + *(grub_uint32_t *) addr = + raw | ((*(grub_uint32_t *) addr) & 0xfc000000); + } + break; + case R_MIPS_GOT16: + if (ELF_ST_BIND (sym->st_info) == STB_LOCAL) + { + Elf_Rel *rel2; + /* Handle partner lo16 relocation. Lower part is + treated as signed. Hence add 0x8000 to compensate. + */ + sym_value += (*(grub_uint16_t *) addr << 16) + + 0x8000; + for (rel2 = rel + 1; rel2 < max; rel2++) + if (ELF_R_SYM (rel2->r_info) + == ELF_R_SYM (rel->r_info) + && ELF_R_TYPE (rel2->r_info) == R_MIPS_LO16) + { + sym_value += *(grub_int16_t *) + ((char *) seg->addr + rel2->r_offset +#ifdef GRUB_CPU_WORDS_BIGENDIAN + + 2 +#endif + ); + break; + } + sym_value &= 0xffff0000; + *(grub_uint16_t *) addr = 0; + } + /* Fallthrough. */ + case R_MIPS_CALL16: + { + grub_uint32_t *gpptr = mod->gotptr; + /* FIXME: reuse*/ +#ifdef GRUB_CPU_WORDS_BIGENDIAN + addr += 2; +#endif + *gpptr = sym_value + *(grub_uint16_t *) addr; + *(grub_uint16_t *) addr + = sizeof (grub_uint32_t) * (gpptr - (grub_uint32_t *) mod->got); + mod->gotptr = gpptr + 1; + break; + } + case R_MIPS_JALR: + break; + default: + { + return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, + N_("relocation 0x%x is not implemented yet"), + ELF_R_TYPE (rel->r_info)); + } + break; + } + } + + return GRUB_ERR_NONE; +} + +void +grub_arch_dl_init_linker (void) +{ + grub_dl_register_symbol ("__gnu_local_gp", &__gnu_local_gp_dummy, 0, 0); + grub_dl_register_symbol ("_gp_disp", &_gp_disp_dummy, 0, 0); +} + |