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 #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_exec(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 #define COPY_UNALIGNED_HWORD(sw, tw, align) \
  79   { \
  80     void *__s = &(sw), *__t = &(tw); \
  81     unsigned short *__s2 = __s, *__t2 =__t; \
  82     unsigned char *__s1 = __s, *__t1 =__t; \
  83     switch ((align)) \
  84     { \
  85     case 0: \
  86       *__t2 = *__s2; \
  87       break; \
  88     default: \
  89       *__t1++ = *__s1++; \
  90       *__t1 = *__s1; \
  91       break; \
  92     } \
  93   }
  94
  95 int apply_relocate_add(Elf32_Shdr *sechdrs,
  96                    const char *strtab,
  97                    unsigned int symindex,
  98                    unsigned int relsec,
  99                    struct module *me)
 100 {
 101         unsigned int i;
 102         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
 103         Elf32_Sym *sym;
 104         Elf32_Addr relocation;
 105         uint32_t *location;
 106         uint32_t value;
 107         unsigned short *hlocation;
 108         unsigned short hvalue;
 109         int svalue;
 110         int align;
 111
 112         DEBUGP("Applying relocate section %u to %u\n", relsec,
 113                sechdrs[relsec].sh_info);
 114         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 115                 /* This is where to make the change */
 116                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
 117                         + rel[i].r_offset;
 118                 /* This is the symbol it is referring to.  Note that all
 119                    undefined symbols have been resolved.  */
 120                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 121                         + ELF32_R_SYM(rel[i].r_info);
 122                 relocation = sym->st_value + rel[i].r_addend;
 123                 align = (int)location & 3;
 124
 125                 switch (ELF32_R_TYPE(rel[i].r_info)) {
 126                 case R_M32R_32_RELA:
 127                         COPY_UNALIGNED_WORD (*location, value, align);
 128                         value += relocation;
 129                         COPY_UNALIGNED_WORD (value, *location, align);
 130                         break;
 131                 case R_M32R_HI16_ULO_RELA:
 132                         COPY_UNALIGNED_WORD (*location, value, align);
 133                         relocation = (relocation >>16) & 0xffff;
 134                         /* RELA must has 0 at relocation field. */
 135                         value += relocation;
 136                         COPY_UNALIGNED_WORD (value, *location, align);
 137                         break;
 138                 case R_M32R_HI16_SLO_RELA:
 139                         COPY_UNALIGNED_WORD (*location, value, align);
 140                         if (relocation & 0x8000) relocation += 0x10000;
 141                         relocation = (relocation >>16) & 0xffff;
 142                         /* RELA must has 0 at relocation field. */
 143                         value += relocation;
 144                         COPY_UNALIGNED_WORD (value, *location, align);
 145                         break;
 146                 case R_M32R_16_RELA:
 147                         hlocation = (unsigned short *)location;
 148                         relocation = relocation & 0xffff;
 149                         /* RELA must has 0 at relocation field. */
 150                         hvalue = relocation;
 151                         COPY_UNALIGNED_WORD (hvalue, *hlocation, align);
 152                         break;
 153                 case R_M32R_SDA16_RELA:
 154                 case R_M32R_LO16_RELA:
 155                         COPY_UNALIGNED_WORD (*location, value, align);
 156                         relocation = relocation & 0xffff;
 157                         /* RELA must has 0 at relocation field. */
 158                         value += relocation;
 159                         COPY_UNALIGNED_WORD (value, *location, align);
 160                         break;
 161                 case R_M32R_24_RELA:
 162                         COPY_UNALIGNED_WORD (*location, value, align);
 163                         relocation = relocation & 0xffffff;
 164                         /* RELA must has 0 at relocation field. */
 165                         value += relocation;
 166                         COPY_UNALIGNED_WORD (value, *location, align);
 167                         break;
 168                 case R_M32R_18_PCREL_RELA:
 169                         relocation = (relocation - (Elf32_Addr) location);
 170                         if (relocation < -0x20000 || 0x1fffc < relocation)
 171                                 {
 172                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
 173                                         me->name, relocation);
 174                                         return -ENOEXEC;
 175                                 }
 176                         COPY_UNALIGNED_WORD (*location, value, align);
 177                         if (value & 0xffff)
 178                                 {
 179                                         /* RELA must has 0 at relocation field. */
 180                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
 181                                         me->name, value);
 182                                         return -ENOEXEC;
 183                                 }
 184                         relocation = (relocation >> 2) & 0xffff;
 185                         value += relocation;
 186                         COPY_UNALIGNED_WORD (value, *location, align);
 187                         break;
 188                 case R_M32R_10_PCREL_RELA:
 189                         hlocation = (unsigned short *)location;
 190                         relocation = (relocation - (Elf32_Addr) location);
 191                         COPY_UNALIGNED_HWORD (*hlocation, hvalue, align);
 192                         svalue = (int)hvalue;
 193                         svalue = (signed char)svalue << 2;
 194                         relocation += svalue;
 195                         relocation = (relocation >> 2) & 0xff;
 196                         hvalue = hvalue & 0xff00;
 197                         hvalue += relocation;
 198                         COPY_UNALIGNED_HWORD (hvalue, *hlocation, align);
 199                         break;
 200                 case R_M32R_26_PCREL_RELA:
 201                         relocation = (relocation - (Elf32_Addr) location);
 202                         if (relocation < -0x2000000 || 0x1fffffc < relocation)
 203                                 {
 204                                         printk(KERN_ERR "module %s: relocation overflow: %u\n",
 205                                         me->name, relocation);
 206                                         return -ENOEXEC;
 207                                 }
 208                         COPY_UNALIGNED_WORD (*location, value, align);
 209                         if (value & 0xffffff)
 210                                 {
 211                                         /* RELA must has 0 at relocation field. */
 212                                         printk(KERN_ERR "module %s: illegal relocation field: %u\n",
 213                                         me->name, value);
 214                                         return -ENOEXEC;
 215                                 }
 216                         relocation = (relocation >> 2) & 0xffffff;
 217                         value += relocation;
 218                         COPY_UNALIGNED_WORD (value, *location, align);
 219                         break;
 220                 default:
 221                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 222                                me->name, ELF32_R_TYPE(rel[i].r_info));
 223                         return -ENOEXEC;
 224                 }
 225         }
 226         return 0;
 227 }
 228
 229 int apply_relocate(Elf32_Shdr *sechdrs,
 230                        const char *strtab,
 231                        unsigned int symindex,
 232                        unsigned int relsec,
 233                        struct module *me)
 234 {
 235 #if 0
 236         printk(KERN_ERR "module %s: REL RELOCATION unsupported\n",
 237                me->name);
 238         return -ENOEXEC;
 239 #endif
 240         return 0;
 241
 242 }
 243
 244 int module_finalize(const Elf_Ehdr *hdr,
 245                     const Elf_Shdr *sechdrs,
 246                     struct module *me)
 247 {
 248         return 0;
 249 }
 250
 251 void module_arch_cleanup(struct module *mod)
 252 {
 253 }