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
  37void *module_alloc(unsigned long size)
  38{
  39        if (size == 0)
  40                return NULL;
  41
  42        return vmalloc_exec(size);
  43}
  44
  45
  46/* Free memory returned from module_alloc */
  47void module_free(struct module *mod, void *module_region)
  48{
  49        vfree(module_region);
  50}
  51
  52/* We don't need anything special. */
  53int module_frob_arch_sections(Elf_Ehdr *hdr,
  54                              Elf_Shdr *sechdrs,
  55                              char *secstrings,
  56                              struct module *mod)
  57{
  58        return 0;
  59}
  60
  61int apply_relocate_add(Elf32_Shdr *sechdrs,
  62                   const char *strtab,
  63                   unsigned int symindex,
  64                   unsigned int relsec,
  65                   struct module *me)
  66{
  67        unsigned int i;
  68        Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  69        Elf32_Sym *sym;
  70        Elf32_Addr relocation;
  71        uint32_t *location;
  72        uint32_t value;
  73
  74        pr_debug("Applying relocate section %u to %u\n", relsec,
  75                 sechdrs[relsec].sh_info);
  76        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  77                /* This is where to make the change */
  78                location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  79                        + rel[i].r_offset;
  80                /* This is the symbol it is referring to.  Note that all
  81                   undefined symbols have been resolved.  */
  82                sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  83                        + ELF32_R_SYM(rel[i].r_info);
  84                relocation = sym->st_value + rel[i].r_addend;
  85
  86#ifdef CONFIG_SUPERH64
  87                /* For text addresses, bit2 of the st_other field indicates
  88                 * whether the symbol is SHmedia (1) or SHcompact (0).  If
  89                 * SHmedia, the LSB of the symbol needs to be asserted
  90                 * for the CPU to be in SHmedia mode when it starts executing
  91                 * the branch target. */
  92                relocation |= !!(sym->st_other & 4);
  93#endif
  94
  95                switch (ELF32_R_TYPE(rel[i].r_info)) {
  96                case R_SH_DIR32:
  97                        value = get_unaligned(location);
  98                        value += relocation;
  99                        put_unaligned(value, location);
 100                        break;
 101                case R_SH_REL32:
 102                        relocation = (relocation - (Elf32_Addr) location);
 103                        value = get_unaligned(location);
 104                        value += relocation;
 105                        put_unaligned(value, location);
 106                        break;
 107                case R_SH_IMM_LOW16:
 108                        *location = (*location & ~0x3fffc00) |
 109                                ((relocation & 0xffff) << 10);
 110                        break;
 111                case R_SH_IMM_MEDLOW16:
 112                        *location = (*location & ~0x3fffc00) |
 113                                (((relocation >> 16) & 0xffff) << 10);
 114                        break;
 115                case R_SH_IMM_LOW16_PCREL:
 116                        relocation -= (Elf32_Addr) location;
 117                        *location = (*location & ~0x3fffc00) |
 118                                ((relocation & 0xffff) << 10);
 119                        break;
 120                case R_SH_IMM_MEDLOW16_PCREL:
 121                        relocation -= (Elf32_Addr) location;
 122                        *location = (*location & ~0x3fffc00) |
 123                                (((relocation >> 16) & 0xffff) << 10);
 124                        break;
 125                default:
 126                        printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 127                               me->name, ELF32_R_TYPE(rel[i].r_info));
 128                        return -ENOEXEC;
 129                }
 130        }
 131        return 0;
 132}
 133
 134int apply_relocate(Elf32_Shdr *sechdrs,
 135                       const char *strtab,
 136                       unsigned int symindex,
 137                       unsigned int relsec,
 138                       struct module *me)
 139{
 140        printk(KERN_ERR "module %s: REL RELOCATION unsupported\n",
 141               me->name);
 142        return -ENOEXEC;
 143}
 144
 145int module_finalize(const Elf_Ehdr *hdr,
 146                    const Elf_Shdr *sechdrs,
 147                    struct module *me)
 148{
 149        int ret = 0;
 150
 151        ret |= module_dwarf_finalize(hdr, sechdrs, me);
 152
 153        return ret;
 154}
 155
 156void module_arch_cleanup(struct module *mod)
 157{
 158        module_dwarf_cleanup(mod);
 159}
 160