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/config.h>
  19 #include <linux/moduleloader.h>
  20 #include <linux/elf.h>
  21 #include <linux/vmalloc.h>
  22 #include <linux/fs.h>
  23 #include <linux/string.h>
  24 #include <linux/kernel.h>
  25
  26 #if 0
  27 #define DEBUGP printk
  28 #else
  29 #define DEBUGP(fmt...)
  30 #endif
  31
  32 void *module_alloc(unsigned long size)
  33 {
  34         if (size == 0)
  35                 return NULL;
  36 #ifdef CONFIG_MMU
  37         return vmalloc_exec(size);
  38 #else
  39         return vmalloc(size);
  40 #endif
  41 }
  42
  43
  44 /* Free memory returned from module_alloc */
  45 void module_free(struct module *mod, void *module_region)
  46 {
  47         vfree(module_region);
  48         /* FIXME: If module_region == mod->init_region, trim exception
  49            table entries. */
  50 }
  51
  52 /* We don't need anything special. */
  53 int module_frob_arch_sections(Elf_Ehdr *hdr,
  54                               Elf_Shdr *sechdrs,
  55                               char *secstrings,
  56                               struct module *mod)
  57 {
  58         return 0;
  59 }
  60
  61 #define COPY_UNALIGNED_WORD(sw, tw, align) \
  62 { \
  63         void *__s = &(sw), *__t = &(tw); \
  64         unsigned short *__s2 = __s, *__t2 =__t; \
  65         unsigned char *__s1 = __s, *__t1 =__t; \
  66         switch ((align)) \
  67         { \
  68         case 0: \
  69                 *(unsigned long *) __t = *(unsigned long *) __s; \
  70                 break; \
  71         case 2: \
  72                 *__t2++ = *__s2++; \
  73                 *__t2 = *__s2; \
  74                 break; \
  75         default: \
  76                 *__t1++ = *__s1++; \
  77                 *__t1++ = *__s1++; \
  78                 *__t1++ = *__s1++; \
  79                 *__t1 = *__s1; \
  80                 break; \
  81         } \
  82 }
  83
  84 #define COPY_UNALIGNED_HWORD(sw, tw, align) \
  85   { \
  86     void *__s = &(sw), *__t = &(tw); \
  87     unsigned short *__s2 = __s, *__t2 =__t; \
  88     unsigned char *__s1 = __s, *__t1 =__t; \
  89     switch ((align)) \
  90     { \
  91     case 0: \
  92       *__t2 = *__s2; \
  93       break; \
  94     default: \
  95       *__t1++ = *__s1++; \
  96       *__t1 = *__s1; \
  97       break; \
  98     } \
  99   }
 100
 101 int apply_relocate_add(Elf32_Shdr *sechdrs,
 102                    const char *strtab,
 103                    unsigned int symindex,
 104                    unsigned int relsec,
 105                    struct module *me)
 106 {
 107         unsigned int i;
 108         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
 109         Elf32_Sym *sym;
 110         Elf32_Addr relocation;
 111         uint32_t *location;
 112         uint32_t value;
 113         unsigned short *hlocation;
 114         unsigned short hvalue;
 115         int svalue;
 116         int align;
 117
 118         DEBUGP("Applying relocate section %u to %u\n", relsec,
 119                sechdrs[relsec].sh_info);
 120         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 121                 /* This is where to make the change */
 122                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
 123                         + rel[i].r_offset;
 124                 /* This is the symbol it is referring to.  Note that all
 125                    undefined symbols have been resolved.  */
 126                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 127                         + ELF32_R_SYM(rel[i].r_info);
 128                 relocation = sym->st_value + rel[i].r_addend;
 129                 align = (int)location & 3;
 130
 131                 switch (ELF32_R_TYPE(rel[i].r_info)) {
 132                 case R_M32R_32_RELA:
 133                         COPY_UNALIGNED_WORD (*location, value, align);
 134                         value += relocation;
 135                         COPY_UNALIGNED_WORD (value, *location, align);
 136                         break;
 137                 case R_M32R_HI16_ULO_RELA:
 138                         COPY_UNALIGNED_WORD (*location, value, align);
 139                         relocation = (relocation >>16) & 0xffff;
 140                         /* RELA must has 0 at relocation field. */
 141                         value += relocation;
 142                         COPY_UNALIGNED_WORD (value, *location, align);
 143                         break;
 144                 case R_M32R_HI16_SLO_RELA:
 145                         COPY_UNALIGNED_WORD (*location, value, align);
 146                         if (relocation & 0x8000) relocation += 0x10000;
 147                         relocation = (relocation >>16) & 0xffff;
 148                         /* RELA must has 0 at relocation field. */
 149                         value += relocation;
 150                         COPY_UNALIGNED_WORD (value, *location, align);
 151                         break;
 152                 case R_M32R_16_RELA:
 153                         hlocation = (unsigned short *)location;
 154                         relocation = relocation & 0xffff;
 155                         /* RELA must has 0 at relocation field. */
 156                         hvalue = relocation;
 157                         COPY_UNALIGNED_WORD (hvalue, *hlocation, align);
 158                         break;
 159                 case R_M32R_SDA16_RELA:
 160                 case R_M32R_LO16_RELA:
 161                         COPY_UNALIGNED_WORD (*location, value, align);
 162                         relocation = relocation & 0xffff;
 163                         /* RELA must has 0 at relocation field. */
 164                         value += relocation;
 165                         COPY_UNALIGNED_WORD (value, *location, align);
 166                         break;
 167                 case R_M32R_24_RELA:
 168                         COPY_UNALIGNED_WORD (*location, value, align);
 169                         relocation = relocation & 0xffffff;
 170                         /* RELA must has 0 at relocation field. */
 171                         value += relocation;
 172                         COPY_UNALIGNED_WORD (value, *location, align);
 173                         break;
 174                 case R_M32R_18_PCREL_RELA:
 175                         relocation = (relocation - (Elf32_Addr) location);
 176                         if (relocation < -0x20000 || 0x1fffc < relocation)
 177                                 {
 178                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
 179                                         me->name, relocation);
 180                                         return -ENOEXEC;
 181                                 }
 182                         COPY_UNALIGNED_WORD (*location, value, align);
 183                         if (value & 0xffff)
 184                                 {
 185                                         /* RELA must has 0 at relocation field. */
 186                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
 187                                         me->name, value);
 188                                         return -ENOEXEC;
 189                                 }
 190                         relocation = (relocation >> 2) & 0xffff;
 191                         value += relocation;
 192                         COPY_UNALIGNED_WORD (value, *location, align);
 193                         break;
 194                 case R_M32R_10_PCREL_RELA:
 195                         hlocation = (unsigned short *)location;
 196                         relocation = (relocation - (Elf32_Addr) location);
 197                         COPY_UNALIGNED_HWORD (*hlocation, hvalue, align);
 198                         svalue = (int)hvalue;
 199                         svalue = (signed char)svalue << 2;
 200                         relocation += svalue;
 201                         relocation = (relocation >> 2) & 0xff;
 202                         hvalue = hvalue & 0xff00;
 203                         hvalue += relocation;
 204                         COPY_UNALIGNED_HWORD (hvalue, *hlocation, align);
 205                         break;
 206                 case R_M32R_26_PCREL_RELA:
 207                         relocation = (relocation - (Elf32_Addr) location);
 208                         if (relocation < -0x2000000 || 0x1fffffc < relocation)
 209                                 {
 210                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
 211                                         me->name, relocation);
 212                                         return -ENOEXEC;
 213                                 }
 214                         COPY_UNALIGNED_WORD (*location, value, align);
 215                         if (value & 0xffffff)
 216                                 {
 217                                         /* RELA must has 0 at relocation field. */
 218                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
 219                                         me->name, value);
 220                                         return -ENOEXEC;
 221                                 }
 222                         relocation = (relocation >> 2) & 0xffffff;
 223                         value += relocation;
 224                         COPY_UNALIGNED_WORD (value, *location, align);
 225                         break;
 226                 default:
 227                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 228                                me->name, ELF32_R_TYPE(rel[i].r_info));
 229                         return -ENOEXEC;
 230                 }
 231         }
 232         return 0;
 233 }
 234
 235 int apply_relocate(Elf32_Shdr *sechdrs,
 236                        const char *strtab,
 237                        unsigned int symindex,
 238                        unsigned int relsec,
 239                        struct module *me)
 240 {
 241 #if 0
 242         printk(KERN_ERR "module %s: REL RELOCATION unsupported\n",
 243                me->name);
 244         return -ENOEXEC;
 245 #endif
 246         return 0;
 247
 248 }
 249
 250 int module_finalize(const Elf_Ehdr *hdr,
 251                     const Elf_Shdr *sechdrs,
 252                     struct module *me)
 253 {
 254         return 0;
 255 }
 256
 257 void module_arch_cleanup(struct module *mod)
 258 {
 259 }