target/linux/generic-2.6/patches-2.6.30/027-mips_module_reloc.patch

   1 --- a/arch/mips/Makefile
   2 +++ b/arch/mips/Makefile
   3 @@ -83,7 +83,7 @@ all-$(CONFIG_BOOT_ELF64)      := $(vmlinux-64
   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 +43,116 @@ 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  void *module_alloc(unsigned long size)
 143  {
 144  #ifdef MODULE_START
 145 @@ -58,23 +168,101 @@ void *module_alloc(unsigned long size)
 146
 147         return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL);
 148  #else
 149 +       void *ptr;
 150 +
 151         if (size == 0)
 152                 return NULL;
 153 -       return vmalloc(size);
 154 +
 155 +       ptr = alloc_phys(size);
 156 +
 157 +       /* If we failed to allocate physically contiguous memory,
 158 +        * fall back to regular vmalloc. The module loader code will
 159 +        * create jump tables to handle long jumps */
 160 +       if (!ptr)
 161 +               return vmalloc(size);
 162 +
 163 +       return ptr;
 164 +#endif
 165 +}
 166 +
 167 +static inline bool is_phys_addr(void *ptr)
 168 +{
 169 +#ifdef CONFIG_64BIT
 170 +       return (KSEGX((unsigned long)ptr) == CKSEG0);
 171 +#else
 172 +       return (KSEGX(ptr) == KSEG0);
 173  #endif
 174  }
 175
 176  /* Free memory returned from module_alloc */
 177  void module_free(struct module *mod, void *module_region)
 178  {
 179 -       vfree(module_region);
 180 +       if (is_phys_addr(module_region)) {
 181 +               if (mod->module_init == module_region)
 182 +                       free_phys(module_region, mod->init_size);
 183 +               else if (mod->module_core == module_region)
 184 +                       free_phys(module_region, mod->core_size);
 185 +               else
 186 +                       BUG();
 187 +       } else {
 188 +               vfree(module_region);
 189 +       }
 190         /* FIXME: If module_region == mod->init_region, trim exception
 191             table entries. */
 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 @@ -97,27 +285,37 @@ static int apply_r_mips_32_rela(struct m
 250         return 0;
 251  }
 252
 253 -static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 254 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 255 +                                void *start, Elf_Addr v)
 256  {
 257 -       if (v % 4) {
 258 -               printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
 259 -               return -ENOEXEC;
 260 -       }
 261 +       unsigned *tramp = start + *plt_offset;
 262
 263 -       if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 264 -               printk(KERN_ERR
 265 -                      "module %s: relocation overflow\n",
 266 -                      me->name);
 267 -               return -ENOEXEC;
 268 -       }
 269 +       *plt_offset += 4 * sizeof(int);
 270
 271 -       *location = (*location & ~0x03ffffff) |
 272 -                   ((*location + (v >> 2)) & 0x03ffffff);
 273 +       /* adjust carry for addiu */
 274 +       if (v & 0x00008000)
 275 +               v += 0x10000;
 276
 277 -       return 0;
 278 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 279 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 280 +       tramp[2] = 0x03200008;                  /* jr t9 */
 281 +       tramp[3] = 0x00000000;                  /* nop */
 282 +
 283 +       return (Elf_Addr) tramp;
 284  }
 285
 286 -static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 287 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 288 +{
 289 +       if (is_phys_addr(location))
 290 +               return add_plt_entry_to(&me->arch.phys_plt_offset,
 291 +                               me->arch.phys_plt_tbl, v);
 292 +       else
 293 +               return add_plt_entry_to(&me->arch.virt_plt_offset,
 294 +                               me->arch.virt_plt_tbl, v);
 295 +
 296 +}
 297 +
 298 +static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
 299  {
 300         if (v % 4) {
 301                 printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
 302 @@ -125,17 +323,31 @@ static int apply_r_mips_26_rela(struct m
 303         }
 304
 305         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 306 -               printk(KERN_ERR
 307 +           v = add_plt_entry(me, location, v + (ofs << 2));
 308 +               if (!v) {
 309 +                       printk(KERN_ERR
 310                        "module %s: relocation overflow\n",
 311                        me->name);
 312 -               return -ENOEXEC;
 313 +                       return -ENOEXEC;
 314 +               }
 315 +               ofs = 0;
 316         }
 317
 318 -       *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
 319 +       *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
 320
 321         return 0;
 322  }
 323
 324 +static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 325 +{
 326 +       return set_r_mips_26(me, location, *location & 0x03ffffff, v);
 327 +}
 328 +
 329 +static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 330 +{
 331 +       return set_r_mips_26(me, location, 0, v);
 332 +}
 333 +
 334  static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 335  {
 336         struct mips_hi16 *n;
 337 @@ -400,11 +612,32 @@ int module_finalize(const Elf_Ehdr *hdr,
 338                 list_add(&me->arch.dbe_list, &dbe_list);
 339                 spin_unlock_irq(&dbe_lock);
 340         }
 341 +
 342 +       /* Get rid of the fixup trampoline if we're running the module
 343 +        * from physically mapped address space */
 344 +       if (me->arch.phys_plt_offset == 0) {
 345 +               __module_free(me->arch.phys_plt_tbl);
 346 +               me->arch.phys_plt_tbl = NULL;
 347 +       }
 348 +       if (me->arch.virt_plt_offset == 0) {
 349 +               __module_free(me->arch.virt_plt_tbl);
 350 +               me->arch.virt_plt_tbl = NULL;
 351 +       }
 352 +
 353         return 0;
 354  }
 355
 356  void module_arch_cleanup(struct module *mod)
 357  {
 358 +       if (mod->arch.phys_plt_tbl) {
 359 +               __module_free(mod->arch.phys_plt_tbl);
 360 +               mod->arch.phys_plt_tbl = NULL;
 361 +       }
 362 +       if (mod->arch.virt_plt_tbl) {
 363 +               __module_free(mod->arch.virt_plt_tbl);
 364 +               mod->arch.virt_plt_tbl = NULL;
 365 +       }
 366 +
 367         spin_lock_irq(&dbe_lock);
 368         list_del(&mod->arch.dbe_list);
 369         spin_unlock_irq(&dbe_lock);