target/linux/generic/patches-2.6.33/027-mips_module_reloc.patch

   1 --- a/arch/mips/Makefile
   2 +++ b/arch/mips/Makefile
   3 @@ -93,7 +93,7 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
   4  cflags-y                       += -G 0 -mno-abicalls -fno-pic -pipe
   5  cflags-y                       += -msoft-float
   6  LDFLAGS_vmlinux                        += -G 0 -static -n -nostdlib
   7 -MODFLAGS                       += -mlong-calls
   8 +MODFLAGS                       += -mno-long-calls
   9
  10  cflags-y += -ffreestanding
  11
  12 --- a/arch/mips/include/asm/module.h
  13 +++ b/arch/mips/include/asm/module.h
  14 @@ -9,6 +9,11 @@ struct mod_arch_specific {
  15         struct list_head dbe_list;
  16         const struct exception_table_entry *dbe_start;
  17         const struct exception_table_entry *dbe_end;
  18 +
  19 +       void *phys_plt_tbl;
  20 +       void *virt_plt_tbl;
  21 +       unsigned int phys_plt_offset;
  22 +       unsigned int virt_plt_offset;
  23  };
  24
  25  typedef uint8_t Elf64_Byte;            /* Type for a 8-bit quantity.  */
  26 --- a/arch/mips/kernel/module.c
  27 +++ b/arch/mips/kernel/module.c
  28 @@ -43,6 +43,117 @@ static struct mips_hi16 *mips_hi16_list;
  29  static LIST_HEAD(dbe_list);
  30  static DEFINE_SPINLOCK(dbe_lock);
  31
  32 +/*
  33 + * Get the potential max trampolines size required of the init and
  34 + * non-init sections. Only used if we cannot find enough contiguous
  35 + * physically mapped memory to put the module into.
  36 + */
  37 +static unsigned int
  38 +get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
  39 +             const char *secstrings, unsigned int symindex, bool is_init)
  40 +{
  41 +       unsigned long ret = 0;
  42 +       unsigned int i, j;
  43 +       Elf_Sym *syms;
  44 +
  45 +       /* Everything marked ALLOC (this includes the exported symbols) */
  46 +       for (i = 1; i < hdr->e_shnum; ++i) {
  47 +               unsigned int info = sechdrs[i].sh_info;
  48 +
  49 +               if (sechdrs[i].sh_type != SHT_REL
  50 +                   && sechdrs[i].sh_type != SHT_RELA)
  51 +                       continue;
  52 +
  53 +               /* Not a valid relocation section? */
  54 +               if (info >= hdr->e_shnum)
  55 +                       continue;
  56 +
  57 +               /* Don't bother with non-allocated sections */
  58 +               if (!(sechdrs[info].sh_flags & SHF_ALLOC))
  59 +                       continue;
  60 +
  61 +               /* If it's called *.init*, and we're not init, we're
  62 +                   not interested */
  63 +               if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
  64 +                   != is_init)
  65 +                       continue;
  66 +
  67 +               syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
  68 +               if (sechdrs[i].sh_type == SHT_REL) {
  69 +                       Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
  70 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
  71 +
  72 +                       for (j = 0; j < size; ++j) {
  73 +                               Elf_Sym *sym;
  74 +
  75 +                               if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
  76 +                                       continue;
  77 +
  78 +                               sym = syms + ELF_MIPS_R_SYM(rel[j]);
  79 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
  80 +                                       continue;
  81 +
  82 +                               ret += 4 * sizeof(int);
  83 +                       }
  84 +               } else {
  85 +                       Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
  86 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
  87 +
  88 +                       for (j = 0; j < size; ++j) {
  89 +                               Elf_Sym *sym;
  90 +
  91 +                               if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
  92 +                                       continue;
  93 +
  94 +                               sym = syms + ELF_MIPS_R_SYM(rela[j]);
  95 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
  96 +                                       continue;
  97 +
  98 +                               ret += 4 * sizeof(int);
  99 +                       }
 100 +               }
 101 +       }
 102 +
 103 +       return ret;
 104 +}
 105 +
 106 +#ifndef MODULE_START
 107 +static void *alloc_phys(unsigned long size)
 108 +{
 109 +       unsigned order;
 110 +       struct page *page;
 111 +       struct page *p;
 112 +
 113 +       size = PAGE_ALIGN(size);
 114 +       order = get_order(size);
 115 +
 116 +       page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
 117 +                       __GFP_THISNODE, order);
 118 +       if (!page)
 119 +               return NULL;
 120 +
 121 +       split_page(page, order);
 122 +
 123 +       for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
 124 +               __free_page(p);
 125 +
 126 +       return page_address(page);
 127 +}
 128 +#endif
 129 +
 130 +static void free_phys(void *ptr, unsigned long size)
 131 +{
 132 +       struct page *page;
 133 +       struct page *end;
 134 +
 135 +       page = virt_to_page(ptr);
 136 +       end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
 137 +
 138 +       for (; page < end; ++page)
 139 +               __free_page(page);
 140 +}
 141 +
 142 +
 143  void *module_alloc(unsigned long size)
 144  {
 145  #ifdef MODULE_START
 146 @@ -58,21 +169,99 @@ void *module_alloc(unsigned long size)
 147
 148         return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL);
 149  #else
 150 +       void *ptr;
 151 +
 152         if (size == 0)
 153                 return NULL;
 154 -       return vmalloc(size);
 155 +
 156 +       ptr = alloc_phys(size);
 157 +
 158 +       /* If we failed to allocate physically contiguous memory,
 159 +        * fall back to regular vmalloc. The module loader code will
 160 +        * create jump tables to handle long jumps */
 161 +       if (!ptr)
 162 +               return vmalloc(size);
 163 +
 164 +       return ptr;
 165 +#endif
 166 +}
 167 +
 168 +static inline bool is_phys_addr(void *ptr)
 169 +{
 170 +#ifdef CONFIG_64BIT
 171 +       return (KSEGX((unsigned long)ptr) == CKSEG0);
 172 +#else
 173 +       return (KSEGX(ptr) == KSEG0);
 174  #endif
 175  }
 176
 177  /* Free memory returned from module_alloc */
 178  void module_free(struct module *mod, void *module_region)
 179  {
 180 -       vfree(module_region);
 181 +       if (is_phys_addr(module_region)) {
 182 +               if (mod->module_init == module_region)
 183 +                       free_phys(module_region, mod->init_size);
 184 +               else if (mod->module_core == module_region)
 185 +                       free_phys(module_region, mod->core_size);
 186 +               else
 187 +                       BUG();
 188 +       } else {
 189 +               vfree(module_region);
 190 +       }
 191 +}
 192 +
 193 +static void *__module_alloc(int size, bool phys)
 194 +{
 195 +       void *ptr;
 196 +
 197 +       if (phys)
 198 +               ptr = kmalloc(size, GFP_KERNEL);
 199 +       else
 200 +               ptr = vmalloc(size);
 201 +       return ptr;
 202 +}
 203 +
 204 +static void __module_free(void *ptr)
 205 +{
 206 +       if (is_phys_addr(ptr))
 207 +               kfree(ptr);
 208 +       else
 209 +               vfree(ptr);
 210  }
 211
 212  int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 213                               char *secstrings, struct module *mod)
 214  {
 215 +       unsigned int symindex = 0;
 216 +       unsigned int core_size, init_size;
 217 +       int i;
 218 +
 219 +       for (i = 1; i < hdr->e_shnum; i++)
 220 +               if (sechdrs[i].sh_type == SHT_SYMTAB)
 221 +                       symindex = i;
 222 +
 223 +       core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
 224 +       init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
 225 +
 226 +       mod->arch.phys_plt_offset = 0;
 227 +       mod->arch.virt_plt_offset = 0;
 228 +       mod->arch.phys_plt_tbl = NULL;
 229 +       mod->arch.virt_plt_tbl = NULL;
 230 +
 231 +       if ((core_size + init_size) == 0)
 232 +               return 0;
 233 +
 234 +       mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
 235 +       if (!mod->arch.phys_plt_tbl)
 236 +               return -ENOMEM;
 237 +
 238 +       mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
 239 +       if (!mod->arch.virt_plt_tbl) {
 240 +               __module_free(mod->arch.phys_plt_tbl);
 241 +               mod->arch.phys_plt_tbl = NULL;
 242 +               return -ENOMEM;
 243 +       }
 244 +
 245         return 0;
 246  }
 247
 248 @@ -95,28 +284,36 @@ static int apply_r_mips_32_rela(struct m
 249         return 0;
 250  }
 251
 252 -static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 253 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 254 +                                void *start, Elf_Addr v)
 255  {
 256 -       if (v % 4) {
 257 -               pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
 258 -                      me->name);
 259 -               return -ENOEXEC;
 260 -       }
 261 +       unsigned *tramp = start + *plt_offset;
 262 +       *plt_offset += 4 * sizeof(int);
 263
 264 -       if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 265 -               printk(KERN_ERR
 266 -                      "module %s: relocation overflow\n",
 267 -                      me->name);
 268 -               return -ENOEXEC;
 269 -       }
 270 +       /* adjust carry for addiu */
 271 +       if (v & 0x00008000)
 272 +               v += 0x10000;
 273
 274 -       *location = (*location & ~0x03ffffff) |
 275 -                   ((*location + (v >> 2)) & 0x03ffffff);
 276 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 277 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 278 +       tramp[2] = 0x03200008;                  /* jr t9 */
 279 +       tramp[3] = 0x00000000;                  /* nop */
 280
 281 -       return 0;
 282 +       return (Elf_Addr) tramp;
 283  }
 284
 285 -static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 286 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 287 +{
 288 +       if (is_phys_addr(location))
 289 +               return add_plt_entry_to(&me->arch.phys_plt_offset,
 290 +                               me->arch.phys_plt_tbl, v);
 291 +       else
 292 +               return add_plt_entry_to(&me->arch.virt_plt_offset,
 293 +                               me->arch.virt_plt_tbl, v);
 294 +
 295 +}
 296 +
 297 +static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
 298  {
 299         if (v % 4) {
 300                 pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
 301 @@ -125,17 +322,31 @@ static int apply_r_mips_26_rela(struct m
 302         }
 303
 304         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 305 -               printk(KERN_ERR
 306 +           v = add_plt_entry(me, location, v + (ofs << 2));
 307 +               if (!v) {
 308 +                       printk(KERN_ERR
 309                        "module %s: relocation overflow\n",
 310                        me->name);
 311 -               return -ENOEXEC;
 312 +                       return -ENOEXEC;
 313 +               }
 314 +               ofs = 0;
 315         }
 316
 317 -       *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
 318 +       *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
 319
 320         return 0;
 321  }
 322
 323 +static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 324 +{
 325 +       return set_r_mips_26(me, location, *location & 0x03ffffff, v);
 326 +}
 327 +
 328 +static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 329 +{
 330 +       return set_r_mips_26(me, location, 0, v);
 331 +}
 332 +
 333  static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 334  {
 335         struct mips_hi16 *n;
 336 @@ -400,11 +611,32 @@ int module_finalize(const Elf_Ehdr *hdr,
 337                 list_add(&me->arch.dbe_list, &dbe_list);
 338                 spin_unlock_irq(&dbe_lock);
 339         }
 340 +
 341 +       /* Get rid of the fixup trampoline if we're running the module
 342 +        * from physically mapped address space */
 343 +       if (me->arch.phys_plt_offset == 0) {
 344 +               __module_free(me->arch.phys_plt_tbl);
 345 +               me->arch.phys_plt_tbl = NULL;
 346 +       }
 347 +       if (me->arch.virt_plt_offset == 0) {
 348 +               __module_free(me->arch.virt_plt_tbl);
 349 +               me->arch.virt_plt_tbl = NULL;
 350 +       }
 351 +
 352         return 0;
 353  }
 354
 355  void module_arch_cleanup(struct module *mod)
 356  {
 357 +       if (mod->arch.phys_plt_tbl) {
 358 +               __module_free(mod->arch.phys_plt_tbl);
 359 +               mod->arch.phys_plt_tbl = NULL;
 360 +       }
 361 +       if (mod->arch.virt_plt_tbl) {
 362 +               __module_free(mod->arch.virt_plt_tbl);
 363 +               mod->arch.virt_plt_tbl = NULL;
 364 +       }
 365 +
 366         spin_lock_irq(&dbe_lock);
 367         list_del(&mod->arch.dbe_list);
 368         spin_unlock_irq(&dbe_lock);