165 lines
4.2 KiB
C
165 lines
4.2 KiB
C
/* dl.c - arch-dependent part of loadable module support */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2013 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <grub/dl.h>
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#include <grub/elf.h>
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#include <grub/misc.h>
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#include <grub/err.h>
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#include <grub/mm.h>
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#include <grub/i18n.h>
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#include <grub/cpu/reloc.h>
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struct trampoline
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{
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#define LDR 0x58000050
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#define BR 0xd61f0200
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grub_uint32_t ldr; /* ldr x16, 8 */
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grub_uint32_t br; /* br x16 */
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grub_uint64_t addr;
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};
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/*
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* Check if EHDR is a valid ELF header.
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*/
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grub_err_t
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grub_arch_dl_check_header (void *ehdr)
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{
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Elf_Ehdr *e = ehdr;
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/* Check the magic numbers. */
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if (e->e_ident[EI_CLASS] != ELFCLASS64
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|| e->e_ident[EI_DATA] != ELFDATA2LSB || e->e_machine != EM_AARCH64)
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return grub_error (GRUB_ERR_BAD_OS,
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N_("invalid arch-dependent ELF magic"));
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return GRUB_ERR_NONE;
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}
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#pragma GCC diagnostic ignored "-Wcast-align"
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grub_err_t
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grub_arch_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
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grub_size_t *got)
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{
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const Elf_Ehdr *e = ehdr;
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const Elf_Shdr *s;
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unsigned i;
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*tramp = 0;
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*got = 0;
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for (i = 0, s = (const Elf_Shdr *) ((grub_addr_t) e + e->e_shoff);
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i < e->e_shnum;
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i++, s = (const Elf_Shdr *) ((grub_addr_t) s + e->e_shentsize))
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if (s->sh_type == SHT_REL || s->sh_type == SHT_RELA)
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{
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const Elf_Rel *rel, *max;
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for (rel = (const Elf_Rel *) ((grub_addr_t) e + s->sh_offset),
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max = rel + s->sh_size / s->sh_entsize;
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rel < max;
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rel = (const Elf_Rel *) ((grub_addr_t) rel + s->sh_entsize))
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switch (ELF_R_TYPE (rel->r_info))
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{
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case R_AARCH64_CALL26:
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case R_AARCH64_JUMP26:
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{
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*tramp += sizeof (struct trampoline);
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break;
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}
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}
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}
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return GRUB_ERR_NONE;
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}
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/*
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* Unified function for both REL and RELA
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*/
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grub_err_t
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grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
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Elf_Shdr *s, grub_dl_segment_t seg)
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{
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Elf_Rel *rel, *max;
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for (rel = (Elf_Rel *) ((char *) ehdr + s->sh_offset),
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max = (Elf_Rel *) ((char *) rel + s->sh_size);
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rel < max;
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rel = (Elf_Rel *) ((char *) rel + s->sh_entsize))
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{
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Elf_Sym *sym;
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void *place;
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grub_uint64_t sym_addr;
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if (rel->r_offset >= seg->size)
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return grub_error (GRUB_ERR_BAD_MODULE,
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"reloc offset is out of the segment");
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sym = (Elf_Sym *) ((char *) mod->symtab
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+ mod->symsize * ELF_R_SYM (rel->r_info));
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sym_addr = sym->st_value;
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if (s->sh_type == SHT_RELA)
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sym_addr += ((Elf_Rela *) rel)->r_addend;
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place = (void *) ((grub_addr_t) seg->addr + rel->r_offset);
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switch (ELF_R_TYPE (rel->r_info))
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{
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case R_AARCH64_ABS64:
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{
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grub_uint64_t *abs_place = place;
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grub_dprintf ("dl", " reloc_abs64 %p => 0x%016llx\n",
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place, (unsigned long long) sym_addr);
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*abs_place = (grub_uint64_t) sym_addr;
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}
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break;
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case R_AARCH64_CALL26:
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case R_AARCH64_JUMP26:
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{
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grub_int64_t offset = sym_addr - (grub_uint64_t) place;
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if (!grub_arm_64_check_xxxx26_offset (offset))
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{
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struct trampoline *tp = mod->trampptr;
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mod->trampptr = tp + 1;
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tp->ldr = LDR;
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tp->br = BR;
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tp->addr = sym_addr;
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offset = (grub_uint8_t *) tp - (grub_uint8_t *) place;
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}
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if (!grub_arm_64_check_xxxx26_offset (offset))
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return grub_error (GRUB_ERR_BAD_MODULE,
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"trampoline out of range");
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grub_arm64_set_xxxx26_offset (place, offset);
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}
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break;
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default:
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return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
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N_("relocation 0x%x is not implemented yet"),
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ELF_R_TYPE (rel->r_info));
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}
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}
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return GRUB_ERR_NONE;
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}
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