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arch/openrisc/kernel/module.c 2.02 KB
5a2bbb8f6   Jonas Bonn   OpenRISC: Module ...
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  /*
   * OpenRISC module.c
   *
   * Linux architectural port borrowing liberally from similar works of
   * others.  All original copyrights apply as per the original source
   * declaration.
   *
   * Modifications for the OpenRISC architecture:
   * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
   *
   *      This program 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
   *      2 of the License, or (at your option) any later version.
   */
  
  #include <linux/moduleloader.h>
  #include <linux/elf.h>
  
  int apply_relocate_add(Elf32_Shdr *sechdrs,
  		       const char *strtab,
  		       unsigned int symindex,
  		       unsigned int relsec,
  		       struct module *me)
  {
  	unsigned int i;
  	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  	Elf32_Sym *sym;
  	uint32_t *location;
  	uint32_t value;
  
  	pr_debug("Applying relocate section %u to %u
  ", relsec,
  		 sechdrs[relsec].sh_info);
  	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  		/* This is where to make the change */
  		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  			+ rel[i].r_offset;
  
  		/* This is the symbol it is referring to.  Note that all
  		   undefined symbols have been resolved.  */
  		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  			+ ELF32_R_SYM(rel[i].r_info);
  		value = sym->st_value + rel[i].r_addend;
  
  		switch (ELF32_R_TYPE(rel[i].r_info)) {
  		case R_OR32_32:
  			*location = value;
  			break;
  		case R_OR32_CONST:
  			location = (uint16_t *)location + 1;
  			*((uint16_t *)location) = (uint16_t) (value);
  			break;
  		case R_OR32_CONSTH:
  			location = (uint16_t *)location + 1;
  			*((uint16_t *)location) = (uint16_t) (value >> 16);
  			break;
  		case R_OR32_JUMPTARG:
  			value -= (uint32_t)location;
  			value >>= 2;
  			value &= 0x03ffffff;
  			value |= *location & 0xfc000000;
  			*location = value;
  			break;
  		default:
  			pr_err("module %s: Unknown relocation: %u
  ",
  			       me->name, ELF32_R_TYPE(rel[i].r_info));
  			break;
  		}
  	}
  
  	return 0;
  }