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
  37 int 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
 112 int 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
 123 void module_arch_cleanup(struct module *mod)
 124 {
 125         module_dwarf_cleanup(mod);
 126 }