target/linux/generic-2.6/patches-2.6.32/027-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 *plt_tbl;
  20 +       unsigned int core_plt_offset;
  21 +       unsigned int core_plt_size;
  22 +       unsigned int init_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 +169,68 @@ 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  int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 194                               char *secstrings, struct module *mod)
 195  {
 196 +       unsigned int symindex = 0;
 197 +       unsigned int core_size, init_size;
 198 +       int i;
 199 +
 200 +       for (i = 1; i < hdr->e_shnum; i++)
 201 +               if (sechdrs[i].sh_type == SHT_SYMTAB)
 202 +                       symindex = i;
 203 +
 204 +       core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
 205 +       init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
 206 +
 207 +       mod->arch.core_plt_offset = 0;
 208 +       mod->arch.core_plt_size = core_size;
 209 +       mod->arch.init_plt_offset = core_size;
 210 +       mod->arch.plt_tbl = kmalloc(core_size + init_size, GFP_KERNEL);
 211 +       if (!mod->arch.plt_tbl)
 212 +               return -ENOMEM;
 213 +
 214         return 0;
 215  }
 216
 217 @@ -95,28 +253,40 @@ static int apply_r_mips_32_rela(struct m
 218         return 0;
 219  }
 220
 221 -static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 222 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 223 +                                void *start, Elf_Addr v)
 224  {
 225 -       if (v % 4) {
 226 -               pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
 227 -                      me->name);
 228 -               return -ENOEXEC;
 229 -       }
 230 +       unsigned *tramp = start + *plt_offset;
 231 +       *plt_offset += 4 * sizeof(int);
 232
 233 -       if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 234 -               printk(KERN_ERR
 235 -                      "module %s: relocation overflow\n",
 236 -                      me->name);
 237 -               return -ENOEXEC;
 238 -       }
 239 +       /* adjust carry for addiu */
 240 +       if (v & 0x00008000)
 241 +               v += 0x10000;
 242 +
 243 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 244 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 245 +       tramp[2] = 0x03200008;                  /* jr t9 */
 246 +       tramp[3] = 0x00000000;                  /* nop */
 247
 248 -       *location = (*location & ~0x03ffffff) |
 249 -                   ((*location + (v >> 2)) & 0x03ffffff);
 250 +       return (Elf_Addr) tramp;
 251 +}
 252 +
 253 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 254 +{
 255 +       if (location >= me->module_core &&
 256 +           location < me->module_core + me->core_size)
 257 +               return add_plt_entry_to(&me->arch.core_plt_offset,
 258 +                               me->arch.plt_tbl, v);
 259 +
 260 +       if (location >= me->module_init &&
 261 +           location < me->module_init + me->init_size)
 262 +               return add_plt_entry_to(&me->arch.init_plt_offset,
 263 +                               me->arch.plt_tbl, v);
 264
 265         return 0;
 266  }
 267
 268 -static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 269 +static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
 270  {
 271         if (v % 4) {
 272                 pr_err("module %s: dangerous R_MIPS_26 RELArelocation\n",
 273 @@ -125,17 +295,31 @@ static int apply_r_mips_26_rela(struct m
 274         }
 275
 276         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 277 -               printk(KERN_ERR
 278 +           v = add_plt_entry(me, location, v + (ofs << 2));
 279 +               if (!v) {
 280 +                       printk(KERN_ERR
 281                        "module %s: relocation overflow\n",
 282                        me->name);
 283 -               return -ENOEXEC;
 284 +                       return -ENOEXEC;
 285 +               }
 286 +               ofs = 0;
 287         }
 288
 289 -       *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
 290 +       *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
 291
 292         return 0;
 293  }
 294
 295 +static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 296 +{
 297 +       return set_r_mips_26(me, location, *location & 0x03ffffff, v);
 298 +}
 299 +
 300 +static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 301 +{
 302 +       return set_r_mips_26(me, location, 0, v);
 303 +}
 304 +
 305  static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 306  {
 307         struct mips_hi16 *n;
 308 @@ -400,11 +584,23 @@ int module_finalize(const Elf_Ehdr *hdr,
 309                 list_add(&me->arch.dbe_list, &dbe_list);
 310                 spin_unlock_irq(&dbe_lock);
 311         }
 312 +
 313 +       /* Get rid of the fixup trampoline if we're running the module
 314 +        * from physically mapped address space */
 315 +       if (me->arch.core_plt_offset == 0 &&
 316 +           me->arch.init_plt_offset == me->arch.core_plt_size &&
 317 +           is_phys_addr(me->module_core)) {
 318 +               kfree(me->arch.plt_tbl);
 319 +               me->arch.plt_tbl = NULL;
 320 +       }
 321 +
 322         return 0;
 323  }
 324
 325  void module_arch_cleanup(struct module *mod)
 326  {
 327 +       if (mod->arch.plt_tbl)
 328 +               kfree(mod->arch.plt_tbl);
 329         spin_lock_irq(&dbe_lock);
 330         list_del(&mod->arch.dbe_list);
 331         spin_unlock_irq(&dbe_lock);