release/src-rt-6.x.4708/linux/linux-2.6.36/arch/m32r/kernel/module.c

   1 /*  Kernel module help for M32R.
   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
  18 #include <linux/moduleloader.h>
  19 #include <linux/elf.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/fs.h>
  22 #include <linux/string.h>
  23 #include <linux/kernel.h>
  24
  25 #define DEBUGP(fmt...)
  26
  27 void *module_alloc(unsigned long size)
  28 {
  29         if (size == 0)
  30                 return NULL;
  31 #ifdef CONFIG_MMU
  32         return vmalloc_exec(size);
  33 #else
  34         return vmalloc(size);
  35 #endif
  36 }
  37
  38
  39 /* Free memory returned from module_alloc */
  40 void module_free(struct module *mod, void *module_region)
  41 {
  42         vfree(module_region);
  43 }
  44
  45 /* We don't need anything special. */
  46 int module_frob_arch_sections(Elf_Ehdr *hdr,
  47                               Elf_Shdr *sechdrs,
  48                               char *secstrings,
  49                               struct module *mod)
  50 {
  51         return 0;
  52 }
  53
  54 #define COPY_UNALIGNED_WORD(sw, tw, align) \
  55 { \
  56         void *__s = &(sw), *__t = &(tw); \
  57         unsigned short *__s2 = __s, *__t2 =__t; \
  58         unsigned char *__s1 = __s, *__t1 =__t; \
  59         switch ((align)) \
  60         { \
  61         case 0: \
  62                 *(unsigned long *) __t = *(unsigned long *) __s; \
  63                 break; \
  64         case 2: \
  65                 *__t2++ = *__s2++; \
  66                 *__t2 = *__s2; \
  67                 break; \
  68         default: \
  69                 *__t1++ = *__s1++; \
  70                 *__t1++ = *__s1++; \
  71                 *__t1++ = *__s1++; \
  72                 *__t1 = *__s1; \
  73                 break; \
  74         } \
  75 }
  76
  77 #define COPY_UNALIGNED_HWORD(sw, tw, align) \
  78   { \
  79     void *__s = &(sw), *__t = &(tw); \
  80     unsigned short *__s2 = __s, *__t2 =__t; \
  81     unsigned char *__s1 = __s, *__t1 =__t; \
  82     switch ((align)) \
  83     { \
  84     case 0: \
  85       *__t2 = *__s2; \
  86       break; \
  87     default: \
  88       *__t1++ = *__s1++; \
  89       *__t1 = *__s1; \
  90       break; \
  91     } \
  92   }
  93
  94 int apply_relocate_add(Elf32_Shdr *sechdrs,
  95                    const char *strtab,
  96                    unsigned int symindex,
  97                    unsigned int relsec,
  98                    struct module *me)
  99 {
 100         unsigned int i;
 101         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
 102         Elf32_Sym *sym;
 103         Elf32_Addr relocation;
 104         uint32_t *location;
 105         uint32_t value;
 106         unsigned short *hlocation;
 107         unsigned short hvalue;
 108         int svalue;
 109         int align;
 110
 111         DEBUGP("Applying relocate section %u to %u\n", relsec,
 112                sechdrs[relsec].sh_info);
 113         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 114                 /* This is where to make the change */
 115                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
 116                         + rel[i].r_offset;
 117                 /* This is the symbol it is referring to.  Note that all
 118                    undefined symbols have been resolved.  */
 119                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 120                         + ELF32_R_SYM(rel[i].r_info);
 121                 relocation = sym->st_value + rel[i].r_addend;
 122                 align = (int)location & 3;
 123
 124                 switch (ELF32_R_TYPE(rel[i].r_info)) {
 125                 case R_M32R_32_RELA:
 126                         COPY_UNALIGNED_WORD (*location, value, align);
 127                         value += relocation;
 128                         COPY_UNALIGNED_WORD (value, *location, align);
 129                         break;
 130                 case R_M32R_HI16_ULO_RELA:
 131                         COPY_UNALIGNED_WORD (*location, value, align);
 132                         relocation = (relocation >>16) & 0xffff;
 133                         /* RELA must has 0 at relocation field. */
 134                         value += relocation;
 135                         COPY_UNALIGNED_WORD (value, *location, align);
 136                         break;
 137                 case R_M32R_HI16_SLO_RELA:
 138                         COPY_UNALIGNED_WORD (*location, value, align);
 139                         if (relocation & 0x8000) relocation += 0x10000;
 140                         relocation = (relocation >>16) & 0xffff;
 141                         /* RELA must has 0 at relocation field. */
 142                         value += relocation;
 143                         COPY_UNALIGNED_WORD (value, *location, align);
 144                         break;
 145                 case R_M32R_16_RELA:
 146                         hlocation = (unsigned short *)location;
 147                         relocation = relocation & 0xffff;
 148                         /* RELA must has 0 at relocation field. */
 149                         hvalue = relocation;
 150                         COPY_UNALIGNED_WORD (hvalue, *hlocation, align);
 151                         break;
 152                 case R_M32R_SDA16_RELA:
 153                 case R_M32R_LO16_RELA:
 154                         COPY_UNALIGNED_WORD (*location, value, align);
 155                         relocation = relocation & 0xffff;
 156                         /* RELA must has 0 at relocation field. */
 157                         value += relocation;
 158                         COPY_UNALIGNED_WORD (value, *location, align);
 159                         break;
 160                 case R_M32R_24_RELA:
 161                         COPY_UNALIGNED_WORD (*location, value, align);
 162                         relocation = relocation & 0xffffff;
 163                         /* RELA must has 0 at relocation field. */
 164                         value += relocation;
 165                         COPY_UNALIGNED_WORD (value, *location, align);
 166                         break;
 167                 case R_M32R_18_PCREL_RELA:
 168                         relocation = (relocation - (Elf32_Addr) location);
 169                         if (relocation < -0x20000 || 0x1fffc < relocation)
 170                                 {
 171                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
 172                                         me->name, relocation);
 173                                         return -ENOEXEC;
 174                                 }
 175                         COPY_UNALIGNED_WORD (*location, value, align);
 176                         if (value & 0xffff)
 177                                 {
 178                                         /* RELA must has 0 at relocation field. */
 179                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
 180                                         me->name, value);
 181                                         return -ENOEXEC;
 182                                 }
 183                         relocation = (relocation >> 2) & 0xffff;
 184                         value += relocation;
 185                         COPY_UNALIGNED_WORD (value, *location, align);
 186                         break;
 187                 case R_M32R_10_PCREL_RELA:
 188                         hlocation = (unsigned short *)location;
 189                         relocation = (relocation - (Elf32_Addr) location);
 190                         COPY_UNALIGNED_HWORD (*hlocation, hvalue, align);
 191                         svalue = (int)hvalue;
 192                         svalue = (signed char)svalue << 2;
 193                         relocation += svalue;
 194                         relocation = (relocation >> 2) & 0xff;
 195                         hvalue = hvalue & 0xff00;
 196                         hvalue += relocation;
 197                         COPY_UNALIGNED_HWORD (hvalue, *hlocation, align);
 198                         break;
 199                 case R_M32R_26_PCREL_RELA:
 200                         relocation = (relocation - (Elf32_Addr) location);
 201                         if (relocation < -0x2000000 || 0x1fffffc < relocation)
 202                                 {
 203                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
 204                                         me->name, relocation);
 205                                         return -ENOEXEC;
 206                                 }
 207                         COPY_UNALIGNED_WORD (*location, value, align);
 208                         if (value & 0xffffff)
 209                                 {
 210                                         /* RELA must has 0 at relocation field. */
 211                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
 212                                         me->name, value);
 213                                         return -ENOEXEC;
 214                                 }
 215                         relocation = (relocation >> 2) & 0xffffff;
 216                         value += relocation;
 217                         COPY_UNALIGNED_WORD (value, *location, align);
 218                         break;
 219                 default:
 220                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 221                                me->name, ELF32_R_TYPE(rel[i].r_info));
 222                         return -ENOEXEC;
 223                 }
 224         }
 225         return 0;
 226 }
 227
 228 int apply_relocate(Elf32_Shdr *sechdrs,
 229                        const char *strtab,
 230                        unsigned int symindex,
 231                        unsigned int relsec,
 232                        struct module *me)
 233 {
 234         return 0;
 235
 236 }
 237
 238 int module_finalize(const Elf_Ehdr *hdr,
 239                     const Elf_Shdr *sechdrs,
 240                     struct module *me)
 241 {
 242         return 0;
 243 }
 244
 245 void module_arch_cleanup(struct module *mod)
 246 {
 247 }