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	* include/grub/dl.h (grub_dl_check_header): New prototype. (grub_arch_dl_check_header): Change return type to grub_err_t, remove size parameter and export function. Update all callers. * kern/dl.c (grub_dl_check_header): New function. (grub_dl_load_core): Use `grub_dl_check_header' instead of `grub_arch_dl_check_header'. Check ELF type. Check if sections are inside the core. * kern/i386/dl.c (grub_arch_dl_check_header): Remove arch independent ELF header checks. * kern/powerpc/dl.c (grub_arch_dl_check_header): Likewise. * loader/i386/pc/multiboot.c (grub_rescue_cmd_multiboot): Use `grub_dl_check_header' instead of explicit checks. Check for the ELF type. * loader/powerpc/ieee1275/linux.c (grub_rescue_cmd_linux): Use `grub_dl_check_header' instead of explicit checks. Remove arch specific ELF header checks.
		
			
				
	
	
		
			140 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			3.7 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) 2002, 2004, 2005  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 2 of the License, or
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 *  (at your option) any later version.
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 *
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 *  This program 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, write to the Free Software
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 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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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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/* Check if EHDR is a valid ELF header.  */
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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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  Elf32_Ehdr *e = ehdr;
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  /* Check the magic numbers.  */
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  if (e->e_ident[EI_CLASS] != ELFCLASS32
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      || e->e_ident[EI_DATA] != ELFDATA2MSB
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      || e->e_machine != EM_PPC)
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    return grub_error (GRUB_ERR_BAD_OS, "invalid arch specific ELF magic");
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  return GRUB_ERR_NONE;
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}
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/* Relocate symbols.  */
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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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{
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  Elf32_Ehdr *e = ehdr;
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  Elf32_Shdr *s;
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  Elf32_Sym *symtab;
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  Elf32_Word entsize;
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  unsigned i;
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  /* Find a symbol table.  */
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  for (i = 0, s = (Elf32_Shdr *) ((char *) e + e->e_shoff);
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       i < e->e_shnum;
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       i++, s = (Elf32_Shdr *) ((char *) s + e->e_shentsize))
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    if (s->sh_type == SHT_SYMTAB)
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      break;
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  if (i == e->e_shnum)
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    return grub_error (GRUB_ERR_BAD_MODULE, "no symtab found");
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  symtab = (Elf32_Sym *) ((char *) e + s->sh_offset);
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  entsize = s->sh_entsize;
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  for (i = 0, s = (Elf32_Shdr *) ((char *) e + e->e_shoff);
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       i < e->e_shnum;
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       i++, s = (Elf32_Shdr *) ((char *) s + e->e_shentsize))
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    if (s->sh_type == SHT_RELA)
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      {
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	grub_dl_segment_t seg;
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	/* Find the target segment.  */
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	for (seg = mod->segment; seg; seg = seg->next)
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	  if (seg->section == s->sh_info)
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	    break;
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	if (seg)
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	  {
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	    Elf32_Rela *rel, *max;
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	    for (rel = (Elf32_Rela *) ((char *) 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++)
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	      {
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		Elf32_Word *addr;
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		Elf32_Sym *sym;
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		grub_uint32_t value;
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		if (seg->size < rel->r_offset)
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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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		addr = (Elf32_Word *) ((char *) seg->addr + rel->r_offset);
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		sym = (Elf32_Sym *) ((char *) symtab
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				     + entsize * ELF32_R_SYM (rel->r_info));
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		/* On the PPC the value does not have an explicit
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		   addend, add it.  */
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		value = sym->st_value + rel->r_addend;
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		switch (ELF32_R_TYPE (rel->r_info))
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		  {
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		  case R_PPC_ADDR16_LO:
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		    *(Elf32_Half *) addr = value;
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		    break;
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		  case R_PPC_REL24:
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		    {
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		      Elf32_Sword delta = value - (Elf32_Word) addr;
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		      if (delta << 6 >> 6 != delta)
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			return grub_error (GRUB_ERR_BAD_MODULE, "Relocation overflow");
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		      *addr = (*addr & 0xfc000003) | (delta & 0x3fffffc);
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		      break;
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		    }
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		  case R_PPC_ADDR16_HA:
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		    *(Elf32_Half *) addr = (value + 0x8000) >> 16;
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		    break;
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		  case R_PPC_ADDR32:
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		    *addr = value;
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		    break;
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		  case R_PPC_REL32:
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		    *addr = value - (Elf32_Word) addr;
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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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				       "This relocation (%d) is not implemented yet",
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				       ELF32_R_TYPE (rel->r_info));
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		  }
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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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