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