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