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
  36void *module_alloc(unsigned long size)
  37{
  38        if (size == 0)
  39                return NULL;
  40
  41        return vmalloc_exec(size);
  42}
  43
  44
  45/* Free memory returned from module_alloc */
  46void module_free(struct module *mod, void *module_region)
  47{
  48        vfree(module_region);
  49}
  50
  51/* We don't need anything special. */
  52int module_frob_arch_sections(Elf_Ehdr *hdr,
  53                              Elf_Shdr *sechdrs,
  54                              char *secstrings,
  55                              struct module *mod)
  56{
  57        return 0;
  58}
  59
  60int apply_relocate_add(Elf32_Shdr *sechdrs,
  61                   const char *strtab,
  62                   unsigned int symindex,
  63                   unsigned int relsec,
  64                   struct module *me)
  65{
  66        unsigned int i;
  67        Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  68        Elf32_Sym *sym;
  69        Elf32_Addr relocation;
  70        uint32_t *location;
  71        uint32_t value;
  72
  73        pr_debug("Applying relocate section %u to %u\n", relsec,
  74                 sechdrs[relsec].sh_info);
  75        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  76                /* This is where to make the change */
  77                location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  78                        + rel[i].r_offset;
  79                /* This is the symbol it is referring to.  Note that all
  80                   undefined symbols have been resolved.  */
  81                sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
  82                        + ELF32_R_SYM(rel[i].r_info);
  83                relocation = sym->st_value + rel[i].r_addend;
  84
  85#ifdef CONFIG_SUPERH64
  86                /* For text addresses, bit2 of the st_other field indicates
  87                 * whether the symbol is SHmedia (1) or SHcompact (0).  If
  88                 * SHmedia, the LSB of the symbol needs to be asserted
  89                 * for the CPU to be in SHmedia mode when it starts executing
  90                 * the branch target. */
  91                relocation |= !!(sym->st_other & 4);
  92#endif
  93
  94                switch (ELF32_R_TYPE(rel[i].r_info)) {
  95                case R_SH_DIR32:
  96                        value = get_unaligned(location);
  97                        value += relocation;
  98                        put_unaligned(value, location);
  99                        break;
 100                case R_SH_REL32:
 101                        relocation = (relocation - (Elf32_Addr) location);
 102                        value = get_unaligned(location);
 103                        value += relocation;
 104                        put_unaligned(value, location);
 105                        break;
 106                case R_SH_IMM_LOW16:
 107                        *location = (*location & ~0x3fffc00) |
 108                                ((relocation & 0xffff) << 10);
 109                        break;
 110                case R_SH_IMM_MEDLOW16:
 111                        *location = (*location & ~0x3fffc00) |
 112                                (((relocation >> 16) & 0xffff) << 10);
 113                        break;
 114                case R_SH_IMM_LOW16_PCREL:
 115                        relocation -= (Elf32_Addr) location;
 116                        *location = (*location & ~0x3fffc00) |
 117                                ((relocation & 0xffff) << 10);
 118                        break;
 119                case R_SH_IMM_MEDLOW16_PCREL:
 120                        relocation -= (Elf32_Addr) location;
 121                        *location = (*location & ~0x3fffc00) |
 122                                (((relocation >> 16) & 0xffff) << 10);
 123                        break;
 124                default:
 125                        printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 126                               me->name, ELF32_R_TYPE(rel[i].r_info));
 127                        return -ENOEXEC;
 128                }
 129        }
 130        return 0;
 131}
 132
 133int apply_relocate(Elf32_Shdr *sechdrs,
 134                       const char *strtab,
 135                       unsigned int symindex,
 136                       unsigned int relsec,
 137                       struct module *me)
 138{
 139        printk(KERN_ERR "module %s: REL RELOCATION unsupported\n",
 140               me->name);
 141        return -ENOEXEC;
 142}
 143
 144int module_finalize(const Elf_Ehdr *hdr,
 145                    const Elf_Shdr *sechdrs,
 146                    struct module *me)
 147{
 148        return module_bug_finalize(hdr, sechdrs, me);
 149}
 150
 151void module_arch_cleanup(struct module *mod)
 152{
 153        module_bug_cleanup(mod);
 154}
 155