target/linux/generic/patches-3.6/305-mips_module_reloc.patch

   1 --- a/arch/mips/Makefile
   2 +++ b/arch/mips/Makefile
   3 @@ -90,8 +90,8 @@ 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 -KBUILD_AFLAGS_MODULE           += -mlong-calls
   8 -KBUILD_CFLAGS_MODULE           += -mlong-calls
   9 +KBUILD_AFLAGS_MODULE           += -mno-long-calls
  10 +KBUILD_CFLAGS_MODULE           += -mno-long-calls
  11
  12  cflags-y += -ffreestanding
  13
  14 --- a/arch/mips/include/asm/module.h
  15 +++ b/arch/mips/include/asm/module.h
  16 @@ -11,6 +11,11 @@ struct mod_arch_specific {
  17         const struct exception_table_entry *dbe_start;
  18         const struct exception_table_entry *dbe_end;
  19         struct mips_hi16 *r_mips_hi16_list;
  20 +
  21 +       void *phys_plt_tbl;
  22 +       void *virt_plt_tbl;
  23 +       unsigned int phys_plt_offset;
  24 +       unsigned int virt_plt_offset;
  25  };
  26
  27  typedef uint8_t Elf64_Byte;            /* Type for a 8-bit quantity.  */
  28 --- a/arch/mips/kernel/module.c
  29 +++ b/arch/mips/kernel/module.c
  30 @@ -42,14 +42,219 @@ struct mips_hi16 {
  31  static LIST_HEAD(dbe_list);
  32  static DEFINE_SPINLOCK(dbe_lock);
  33
  34 -#ifdef MODULE_START
  35 +/*
  36 + * Get the potential max trampolines size required of the init and
  37 + * non-init sections. Only used if we cannot find enough contiguous
  38 + * physically mapped memory to put the module into.
  39 + */
  40 +static unsigned int
  41 +get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
  42 +             const char *secstrings, unsigned int symindex, bool is_init)
  43 +{
  44 +       unsigned long ret = 0;
  45 +       unsigned int i, j;
  46 +       Elf_Sym *syms;
  47 +
  48 +       /* Everything marked ALLOC (this includes the exported symbols) */
  49 +       for (i = 1; i < hdr->e_shnum; ++i) {
  50 +               unsigned int info = sechdrs[i].sh_info;
  51 +
  52 +               if (sechdrs[i].sh_type != SHT_REL
  53 +                   && sechdrs[i].sh_type != SHT_RELA)
  54 +                       continue;
  55 +
  56 +               /* Not a valid relocation section? */
  57 +               if (info >= hdr->e_shnum)
  58 +                       continue;
  59 +
  60 +               /* Don't bother with non-allocated sections */
  61 +               if (!(sechdrs[info].sh_flags & SHF_ALLOC))
  62 +                       continue;
  63 +
  64 +               /* If it's called *.init*, and we're not init, we're
  65 +                   not interested */
  66 +               if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
  67 +                   != is_init)
  68 +                       continue;
  69 +
  70 +               syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
  71 +               if (sechdrs[i].sh_type == SHT_REL) {
  72 +                       Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
  73 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
  74 +
  75 +                       for (j = 0; j < size; ++j) {
  76 +                               Elf_Sym *sym;
  77 +
  78 +                               if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
  79 +                                       continue;
  80 +
  81 +                               sym = syms + ELF_MIPS_R_SYM(rel[j]);
  82 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
  83 +                                       continue;
  84 +
  85 +                               ret += 4 * sizeof(int);
  86 +                       }
  87 +               } else {
  88 +                       Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
  89 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
  90 +
  91 +                       for (j = 0; j < size; ++j) {
  92 +                               Elf_Sym *sym;
  93 +
  94 +                               if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
  95 +                                       continue;
  96 +
  97 +                               sym = syms + ELF_MIPS_R_SYM(rela[j]);
  98 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
  99 +                                       continue;
 100 +
 101 +                               ret += 4 * sizeof(int);
 102 +                       }
 103 +               }
 104 +       }
 105 +
 106 +       return ret;
 107 +}
 108 +
 109 +#ifndef MODULE_START
 110 +static void *alloc_phys(unsigned long size)
 111 +{
 112 +       unsigned order;
 113 +       struct page *page;
 114 +       struct page *p;
 115 +
 116 +       size = PAGE_ALIGN(size);
 117 +       order = get_order(size);
 118 +
 119 +       page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
 120 +                       __GFP_THISNODE, order);
 121 +       if (!page)
 122 +               return NULL;
 123 +
 124 +       split_page(page, order);
 125 +
 126 +       for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
 127 +               __free_page(p);
 128 +
 129 +       return page_address(page);
 130 +}
 131 +#endif
 132 +
 133 +static void free_phys(void *ptr, unsigned long size)
 134 +{
 135 +       struct page *page;
 136 +       struct page *end;
 137 +
 138 +       page = virt_to_page(ptr);
 139 +       end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
 140 +
 141 +       for (; page < end; ++page)
 142 +               __free_page(page);
 143 +}
 144 +
 145 +
 146  void *module_alloc(unsigned long size)
 147  {
 148 +#ifdef MODULE_START
 149         return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
 150                                 GFP_KERNEL, PAGE_KERNEL, -1,
 151                                 __builtin_return_address(0));
 152 +#else
 153 +       void *ptr;
 154 +
 155 +       if (size == 0)
 156 +               return NULL;
 157 +
 158 +       ptr = alloc_phys(size);
 159 +
 160 +       /* If we failed to allocate physically contiguous memory,
 161 +        * fall back to regular vmalloc. The module loader code will
 162 +        * create jump tables to handle long jumps */
 163 +       if (!ptr)
 164 +               return vmalloc(size);
 165 +
 166 +       return ptr;
 167 +#endif
 168  }
 169 +
 170 +static inline bool is_phys_addr(void *ptr)
 171 +{
 172 +#ifdef CONFIG_64BIT
 173 +       return (KSEGX((unsigned long)ptr) == CKSEG0);
 174 +#else
 175 +       return (KSEGX(ptr) == KSEG0);
 176  #endif
 177 +}
 178 +
 179 +/* Free memory returned from module_alloc */
 180 +void module_free(struct module *mod, void *module_region)
 181 +{
 182 +       if (is_phys_addr(module_region)) {
 183 +               if (mod->module_init == module_region)
 184 +                       free_phys(module_region, mod->init_size);
 185 +               else if (mod->module_core == module_region)
 186 +                       free_phys(module_region, mod->core_size);
 187 +               else
 188 +                       BUG();
 189 +       } else {
 190 +               vfree(module_region);
 191 +       }
 192 +}
 193 +
 194 +static void *__module_alloc(int size, bool phys)
 195 +{
 196 +       void *ptr;
 197 +
 198 +       if (phys)
 199 +               ptr = kmalloc(size, GFP_KERNEL);
 200 +       else
 201 +               ptr = vmalloc(size);
 202 +       return ptr;
 203 +}
 204 +
 205 +static void __module_free(void *ptr)
 206 +{
 207 +       if (is_phys_addr(ptr))
 208 +               kfree(ptr);
 209 +       else
 210 +               vfree(ptr);
 211 +}
 212 +
 213 +int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 214 +                             char *secstrings, struct module *mod)
 215 +{
 216 +       unsigned int symindex = 0;
 217 +       unsigned int core_size, init_size;
 218 +       int i;
 219 +
 220 +       for (i = 1; i < hdr->e_shnum; i++)
 221 +               if (sechdrs[i].sh_type == SHT_SYMTAB)
 222 +                       symindex = i;
 223 +
 224 +       core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
 225 +       init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
 226 +
 227 +       mod->arch.phys_plt_offset = 0;
 228 +       mod->arch.virt_plt_offset = 0;
 229 +       mod->arch.phys_plt_tbl = NULL;
 230 +       mod->arch.virt_plt_tbl = NULL;
 231 +
 232 +       if ((core_size + init_size) == 0)
 233 +               return 0;
 234 +
 235 +       mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
 236 +       if (!mod->arch.phys_plt_tbl)
 237 +               return -ENOMEM;
 238 +
 239 +       mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
 240 +       if (!mod->arch.virt_plt_tbl) {
 241 +               __module_free(mod->arch.phys_plt_tbl);
 242 +               mod->arch.phys_plt_tbl = NULL;
 243 +               return -ENOMEM;
 244 +       }
 245 +
 246 +       return 0;
 247 +}
 248
 249  static int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
 250  {
 251 @@ -70,28 +275,36 @@ static int apply_r_mips_32_rela(struct m
 252         return 0;
 253  }
 254
 255 -static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 256 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 257 +                                void *start, Elf_Addr v)
 258  {
 259 -       if (v % 4) {
 260 -               pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
 261 -                      me->name);
 262 -               return -ENOEXEC;
 263 -       }
 264 +       unsigned *tramp = start + *plt_offset;
 265 +       *plt_offset += 4 * sizeof(int);
 266
 267 -       if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 268 -               printk(KERN_ERR
 269 -                      "module %s: relocation overflow\n",
 270 -                      me->name);
 271 -               return -ENOEXEC;
 272 -       }
 273 +       /* adjust carry for addiu */
 274 +       if (v & 0x00008000)
 275 +               v += 0x10000;
 276
 277 -       *location = (*location & ~0x03ffffff) |
 278 -                   ((*location + (v >> 2)) & 0x03ffffff);
 279 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 280 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 281 +       tramp[2] = 0x03200008;                  /* jr t9 */
 282 +       tramp[3] = 0x00000000;                  /* nop */
 283
 284 -       return 0;
 285 +       return (Elf_Addr) tramp;
 286  }
 287
 288 -static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 289 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 290 +{
 291 +       if (is_phys_addr(location))
 292 +               return add_plt_entry_to(&me->arch.phys_plt_offset,
 293 +                               me->arch.phys_plt_tbl, v);
 294 +       else
 295 +               return add_plt_entry_to(&me->arch.virt_plt_offset,
 296 +                               me->arch.virt_plt_tbl, v);
 297 +
 298 +}
 299 +
 300 +static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
 301  {
 302         if (v % 4) {
 303                 pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
 304 @@ -100,17 +313,31 @@ static int apply_r_mips_26_rela(struct m
 305         }
 306
 307         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 308 -               printk(KERN_ERR
 309 +           v = add_plt_entry(me, location, v + (ofs << 2));
 310 +               if (!v) {
 311 +                       printk(KERN_ERR
 312                        "module %s: relocation overflow\n",
 313                        me->name);
 314 -               return -ENOEXEC;
 315 +                       return -ENOEXEC;
 316 +               }
 317 +               ofs = 0;
 318         }
 319
 320 -       *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
 321 +       *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
 322
 323         return 0;
 324  }
 325
 326 +static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 327 +{
 328 +       return set_r_mips_26(me, location, *location & 0x03ffffff, v);
 329 +}
 330 +
 331 +static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 332 +{
 333 +       return set_r_mips_26(me, location, 0, v);
 334 +}
 335 +
 336  static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 337  {
 338         struct mips_hi16 *n;
 339 @@ -405,11 +632,32 @@ int module_finalize(const Elf_Ehdr *hdr,
 340                 list_add(&me->arch.dbe_list, &dbe_list);
 341                 spin_unlock_irq(&dbe_lock);
 342         }
 343 +
 344 +       /* Get rid of the fixup trampoline if we're running the module
 345 +        * from physically mapped address space */
 346 +       if (me->arch.phys_plt_offset == 0) {
 347 +               __module_free(me->arch.phys_plt_tbl);
 348 +               me->arch.phys_plt_tbl = NULL;
 349 +       }
 350 +       if (me->arch.virt_plt_offset == 0) {
 351 +               __module_free(me->arch.virt_plt_tbl);
 352 +               me->arch.virt_plt_tbl = NULL;
 353 +       }
 354 +
 355         return 0;
 356  }
 357
 358  void module_arch_cleanup(struct module *mod)
 359  {
 360 +       if (mod->arch.phys_plt_tbl) {
 361 +               __module_free(mod->arch.phys_plt_tbl);
 362 +               mod->arch.phys_plt_tbl = NULL;
 363 +       }
 364 +       if (mod->arch.virt_plt_tbl) {
 365 +               __module_free(mod->arch.virt_plt_tbl);
 366 +               mod->arch.virt_plt_tbl = NULL;
 367 +       }
 368 +
 369         spin_lock_irq(&dbe_lock);
 370         list_del(&mod->arch.dbe_list);
 371         spin_unlock_irq(&dbe_lock);