target/linux/generic/patches-2.6.36/027-mips_module_reloc.patch

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