LXR linux/arch/sh/kernel/module.c

   1/*  Kernel module help for SH.
   2
   3    SHcompact version by Kaz Kojima and Paul Mundt.
   4
   5    SHmedia bits:
   6
   7        Copyright 2004 SuperH (UK) Ltd
   8        Author: Richard Curnow
   9
  10        Based on the sh version, and on code from the sh64-specific parts of
  11        modutils, originally written by Richard Curnow and Ben Gaster.
  12
  13    This program is free software; you can redistribute it and/or modify
  14    it under the terms of the GNU General Public License as published by
  15    the Free Software Foundation; either version 2 of the License, or
  16    (at your option) any later version.
  17
  18    This program is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program; if not, write to the Free Software
  25    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  26*/
  27#include <linux/moduleloader.h>
  28#include <linux/elf.h>
  29#include <linux/vmalloc.h>
  30#include <linux/bug.h>
  31#include <linux/fs.h>
  32#include <linux/string.h>
  33#include <linux/kernel.h>
  34#include <asm/unaligned.h>
  35#include <asm/dwarf.h>
  36
  37int apply_relocate_add(Elf32_Shdr *sechdrs,
  38                   const char *strtab,
  39                   unsigned int symindex,
  40                   unsigned int relsec,
  41                   struct module *me)
  42{
  43        unsigned int i;
  44        Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  45        Elf32_Sym *sym;
  46        Elf32_Addr relocation;
  47        uint32_t *location;
  48        uint32_t value;
  49
  50        pr_debug("Applying relocate section %u to %u\n", relsec,
  51                 sechdrs[relsec].sh_info);
  52        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  53                /* This is where to make the change */
  54                location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  55                        + rel[i].r_offset;
  56                /* This is the symbol it is referring to.  Note that all
  57                   undefined symbols have been resolved.  */
  58                sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  59                        + ELF32_R_SYM(rel[i].r_info);
  60                relocation = sym->st_value + rel[i].r_addend;
  61
  62#ifdef CONFIG_SUPERH64
  63                /* For text addresses, bit2 of the st_other field indicates
  64                 * whether the symbol is SHmedia (1) or SHcompact (0).  If
  65                 * SHmedia, the LSB of the symbol needs to be asserted
  66                 * for the CPU to be in SHmedia mode when it starts executing
  67                 * the branch target. */
  68                relocation |= !!(sym->st_other & 4);
  69#endif
  70
  71                switch (ELF32_R_TYPE(rel[i].r_info)) {
  72                case R_SH_NONE:
  73                        break;
  74                case R_SH_DIR32:
  75                        value = get_unaligned(location);
  76                        value += relocation;
  77                        put_unaligned(value, location);
  78                        break;
  79                case R_SH_REL32:
  80                        relocation = (relocation - (Elf32_Addr) location);
  81                        value = get_unaligned(location);
  82                        value += relocation;
  83                        put_unaligned(value, location);
  84                        break;
  85                case R_SH_IMM_LOW16:
  86                        *location = (*location & ~0x3fffc00) |
  87                                ((relocation & 0xffff) << 10);
  88                        break;
  89                case R_SH_IMM_MEDLOW16:
  90                        *location = (*location & ~0x3fffc00) |
  91                                (((relocation >> 16) & 0xffff) << 10);
  92                        break;
  93                case R_SH_IMM_LOW16_PCREL:
  94                        relocation -= (Elf32_Addr) location;
  95                        *location = (*location & ~0x3fffc00) |
  96                                ((relocation & 0xffff) << 10);
  97                        break;
  98                case R_SH_IMM_MEDLOW16_PCREL:
  99                        relocation -= (Elf32_Addr) location;
 100                        *location = (*location & ~0x3fffc00) |
 101                                (((relocation >> 16) & 0xffff) << 10);
 102                        break;
 103                default:
 104                        printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 105                               me->name, ELF32_R_TYPE(rel[i].r_info));
 106                        return -ENOEXEC;
 107                }
 108        }
 109        return 0;
 110}
 111
 112int module_finalize(const Elf_Ehdr *hdr,
 113                    const Elf_Shdr *sechdrs,
 114                    struct module *me)
 115{
 116        int ret = 0;
 117
 118        ret |= module_dwarf_finalize(hdr, sechdrs, me);
 119
 120        return ret;
 121}
 122
 123void module_arch_cleanup(struct module *mod)
 124{
 125        module_dwarf_cleanup(mod);
 126}
 127