arch/sh/kernel/module.c

   1 /*  Kernel module help for SH.
   2
   3     This program is free software; you can redistribute it and/or modify
   4     it under the terms of the GNU General Public License as published by
   5     the Free Software Foundation; either version 2 of the License, or
   6     (at your option) any later version.
   7
   8     This program is distributed in the hope that it will be useful,
   9     but WITHOUT ANY WARRANTY; without even the implied warranty of
  10     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11     GNU General Public License for more details.
  12
  13     You should have received a copy of the GNU General Public License
  14     along with this program; if not, write to the Free Software
  15     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16 */
  17 #include <linux/moduleloader.h>
  18 #include <linux/elf.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/fs.h>
  21 #include <linux/string.h>
  22 #include <linux/kernel.h>
  23
  24 #if 0
  25 #define DEBUGP printk
  26 #else
  27 #define DEBUGP(fmt...)
  28 #endif
  29
  30 void *module_alloc(unsigned long size)
  31 {
  32         if (size == 0)
  33                 return NULL;
  34         return vmalloc(size);
  35 }
  36
  37
  38 /* Free memory returned from module_alloc */
  39 void module_free(struct module *mod, void *module_region)
  40 {
  41         vfree(module_region);
  42         /* FIXME: If module_region == mod->init_region, trim exception
  43            table entries. */
  44 }
  45
  46 /* We don't need anything special. */
  47 int module_frob_arch_sections(Elf_Ehdr *hdr,
  48                               Elf_Shdr *sechdrs,
  49                               char *secstrings,
  50                               struct module *mod)
  51 {
  52         return 0;
  53 }
  54
  55 #define COPY_UNALIGNED_WORD(sw, tw, align) \
  56 { \
  57         void *__s = &(sw), *__t = &(tw); \
  58         unsigned short *__s2 = __s, *__t2 = __t; \
  59         unsigned char *__s1 = __s, *__t1 = __t; \
  60         switch ((align)) \
  61         { \
  62         case 0: \
  63                 *(unsigned long *) __t = *(unsigned long *) __s; \
  64                 break; \
  65         case 2: \
  66                 *__t2++ = *__s2++; \
  67                 *__t2 = *__s2; \
  68                 break; \
  69         default: \
  70                 *__t1++ = *__s1++; \
  71                 *__t1++ = *__s1++; \
  72                 *__t1++ = *__s1++; \
  73                 *__t1 = *__s1; \
  74                 break; \
  75         } \
  76 }
  77
  78 int apply_relocate_add(Elf32_Shdr *sechdrs,
  79                    const char *strtab,
  80                    unsigned int symindex,
  81                    unsigned int relsec,
  82                    struct module *me)
  83 {
  84         unsigned int i;
  85         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
  86         Elf32_Sym *sym;
  87         Elf32_Addr relocation;
  88         uint32_t *location;
  89         uint32_t value;
  90         int align;
  91
  92         DEBUGP("Applying relocate section %u to %u\n", relsec,
  93                sechdrs[relsec].sh_info);
  94         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
  95                 /* This is where to make the change */
  96                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
  97                         + rel[i].r_offset;
  98                 /* This is the symbol it is referring to.  Note that all
  99                    undefined symbols have been resolved.  */
 100                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 101                         + ELF32_R_SYM(rel[i].r_info);
 102                 relocation = sym->st_value + rel[i].r_addend;
 103                 align = (int)location & 3;
 104
 105                 switch (ELF32_R_TYPE(rel[i].r_info)) {
 106                 case R_SH_DIR32:
 107                         COPY_UNALIGNED_WORD (*location, value, align);
 108                         value += relocation;
 109                         COPY_UNALIGNED_WORD (value, *location, align);
 110                         break;
 111                 case R_SH_REL32:
 112                         relocation = (relocation - (Elf32_Addr) location);
 113                         COPY_UNALIGNED_WORD (*location, value, align);
 114                         value += relocation;
 115                         COPY_UNALIGNED_WORD (value, *location, align);
 116                         break;
 117                 default:
 118                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 119                                me->name, ELF32_R_TYPE(rel[i].r_info));
 120                         return -ENOEXEC;
 121                 }
 122         }
 123         return 0;
 124 }
 125
 126 int apply_relocate(Elf32_Shdr *sechdrs,
 127                        const char *strtab,
 128                        unsigned int symindex,
 129                        unsigned int relsec,
 130                        struct module *me)
 131 {
 132         printk(KERN_ERR "module %s: REL RELOCATION unsupported\n",
 133                me->name);
 134         return -ENOEXEC;
 135 }
 136
 137 int module_finalize(const Elf_Ehdr *hdr,
 138                     const Elf_Shdr *sechdrs,
 139                     struct module *me)
 140 {
 141         return 0;
 142 }
 143
 144 void module_arch_cleanup(struct module *mod)
 145 {
 146 }