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

   1 Index: linux-2.6.30.4/arch/mips/Makefile
   2 ===================================================================
   3 --- linux-2.6.30.4.orig/arch/mips/Makefile      2009-08-06 16:02:25.000000000 +0200
   4 +++ linux-2.6.30.4/arch/mips/Makefile   2009-08-06 16:02:37.000000000 +0200
   5 @@ -83,7 +83,7 @@
   6  cflags-y                       += -G 0 -mno-abicalls -fno-pic -pipe
   7  cflags-y                       += -msoft-float
   8  LDFLAGS_vmlinux                        += -G 0 -static -n -nostdlib
   9 -MODFLAGS                       += -mlong-calls
  10 +MODFLAGS                       += -mno-long-calls
  11
  12  cflags-y += -ffreestanding
  13
  14 Index: linux-2.6.30.4/arch/mips/include/asm/module.h
  15 ===================================================================
  16 --- linux-2.6.30.4.orig/arch/mips/include/asm/module.h  2009-08-06 16:02:25.000000000 +0200
  17 +++ linux-2.6.30.4/arch/mips/include/asm/module.h       2009-08-06 16:02:37.000000000 +0200
  18 @@ -9,6 +9,11 @@
  19         struct list_head dbe_list;
  20         const struct exception_table_entry *dbe_start;
  21         const struct exception_table_entry *dbe_end;
  22 +
  23 +       void *plt_tbl;
  24 +       unsigned int core_plt_offset;
  25 +       unsigned int core_plt_size;
  26 +       unsigned int init_plt_offset;
  27  };
  28
  29  typedef uint8_t Elf64_Byte;            /* Type for a 8-bit quantity.  */
  30 Index: linux-2.6.30.4/arch/mips/kernel/module.c
  31 ===================================================================
  32 --- linux-2.6.30.4.orig/arch/mips/kernel/module.c       2009-08-06 16:02:36.000000000 +0200
  33 +++ linux-2.6.30.4/arch/mips/kernel/module.c    2009-08-06 16:03:15.000000000 +0200
  34 @@ -43,6 +43,116 @@
  35  static LIST_HEAD(dbe_list);
  36  static DEFINE_SPINLOCK(dbe_lock);
  37
  38 +/*
  39 + * Get the potential max trampolines size required of the init and
  40 + * non-init sections. Only used if we cannot find enough contiguous
  41 + * physically mapped memory to put the module into.
  42 + */
  43 +static unsigned int
  44 +get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
  45 +             const char *secstrings, unsigned int symindex, bool is_init)
  46 +{
  47 +       unsigned long ret = 0;
  48 +       unsigned int i, j;
  49 +       Elf_Sym *syms;
  50 +
  51 +       /* Everything marked ALLOC (this includes the exported symbols) */
  52 +       for (i = 1; i < hdr->e_shnum; ++i) {
  53 +               unsigned int info = sechdrs[i].sh_info;
  54 +
  55 +               if (sechdrs[i].sh_type != SHT_REL
  56 +                   && sechdrs[i].sh_type != SHT_RELA)
  57 +                       continue;
  58 +
  59 +               /* Not a valid relocation section? */
  60 +               if (info >= hdr->e_shnum)
  61 +                       continue;
  62 +
  63 +               /* Don't bother with non-allocated sections */
  64 +               if (!(sechdrs[info].sh_flags & SHF_ALLOC))
  65 +                       continue;
  66 +
  67 +               /* If it's called *.init*, and we're not init, we're
  68 +                   not interested */
  69 +               if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
  70 +                   != is_init)
  71 +                       continue;
  72 +
  73 +               syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
  74 +               if (sechdrs[i].sh_type == SHT_REL) {
  75 +                       Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
  76 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
  77 +
  78 +                       for (j = 0; j < size; ++j) {
  79 +                               Elf_Sym *sym;
  80 +
  81 +                               if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
  82 +                                       continue;
  83 +
  84 +                               sym = syms + ELF_MIPS_R_SYM(rel[j]);
  85 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
  86 +                                       continue;
  87 +
  88 +                               ret += 4 * sizeof(int);
  89 +                       }
  90 +               } else {
  91 +                       Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
  92 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
  93 +
  94 +                       for (j = 0; j < size; ++j) {
  95 +                               Elf_Sym *sym;
  96 +
  97 +                               if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
  98 +                                       continue;
  99 +
 100 +                               sym = syms + ELF_MIPS_R_SYM(rela[j]);
 101 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
 102 +                                       continue;
 103 +
 104 +                               ret += 4 * sizeof(int);
 105 +                       }
 106 +               }
 107 +       }
 108 +
 109 +       return ret;
 110 +}
 111 +
 112 +#ifndef MODULE_START
 113 +static void *alloc_phys(unsigned long size)
 114 +{
 115 +       unsigned order;
 116 +       struct page *page;
 117 +       struct page *p;
 118 +
 119 +       size = PAGE_ALIGN(size);
 120 +       order = get_order(size);
 121 +
 122 +       page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
 123 +                       __GFP_THISNODE, order);
 124 +       if (!page)
 125 +               return NULL;
 126 +
 127 +       split_page(page, order);
 128 +
 129 +       for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
 130 +               __free_page(p);
 131 +
 132 +       return page_address(page);
 133 +}
 134 +#endif
 135 +
 136 +static void free_phys(void *ptr, unsigned long size)
 137 +{
 138 +       struct page *page;
 139 +       struct page *end;
 140 +
 141 +       page = virt_to_page(ptr);
 142 +       end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
 143 +
 144 +       for (; page < end; ++page)
 145 +               __free_page(page);
 146 +}
 147 +
 148  void *module_alloc(unsigned long size)
 149  {
 150  #ifdef MODULE_START
 151 @@ -58,16 +168,45 @@
 152
 153         return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL);
 154  #else
 155 +       void *ptr;
 156 +
 157         if (size == 0)
 158                 return NULL;
 159 -       return vmalloc(size);
 160 +
 161 +       ptr = alloc_phys(size);
 162 +
 163 +       /* If we failed to allocate physically contiguous memory,
 164 +        * fall back to regular vmalloc. The module loader code will
 165 +        * create jump tables to handle long jumps */
 166 +       if (!ptr)
 167 +               return vmalloc(size);
 168 +
 169 +       return ptr;
 170 +#endif
 171 +}
 172 +
 173 +static inline bool is_phys_addr(void *ptr)
 174 +{
 175 +#ifdef CONFIG_64BIT
 176 +       return (KSEGX((unsigned long)ptr) == CKSEG0);
 177 +#else
 178 +       return (KSEGX(ptr) == KSEG0);
 179  #endif
 180  }
 181
 182  /* Free memory returned from module_alloc */
 183  void module_free(struct module *mod, void *module_region)
 184  {
 185 -       vfree(module_region);
 186 +       if (is_phys_addr(module_region)) {
 187 +               if (mod->module_init == module_region)
 188 +                       free_phys(module_region, mod->init_size);
 189 +               else if (mod->module_core == module_region)
 190 +                       free_phys(module_region, mod->core_size);
 191 +               else
 192 +                       BUG();
 193 +       } else {
 194 +               vfree(module_region);
 195 +       }
 196         /* FIXME: If module_region == mod->init_region, trim exception
 197             table entries. */
 198  }
 199 @@ -75,6 +214,24 @@
 200  int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 201                               char *secstrings, struct module *mod)
 202  {
 203 +       unsigned int symindex = 0;
 204 +       unsigned int core_size, init_size;
 205 +       int i;
 206 +
 207 +       for (i = 1; i < hdr->e_shnum; i++)
 208 +               if (sechdrs[i].sh_type == SHT_SYMTAB)
 209 +                       symindex = i;
 210 +
 211 +       core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
 212 +       init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
 213 +
 214 +       mod->arch.core_plt_offset = 0;
 215 +       mod->arch.core_plt_size = core_size;
 216 +       mod->arch.init_plt_offset = core_size;
 217 +       mod->arch.plt_tbl = kmalloc(core_size + init_size, GFP_KERNEL);
 218 +       if (!mod->arch.plt_tbl)
 219 +               return -ENOMEM;
 220 +
 221         return 0;
 222  }
 223
 224 @@ -97,27 +254,41 @@
 225         return 0;
 226  }
 227
 228 -static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 229 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 230 +                                void *start, Elf_Addr v)
 231  {
 232 -       if (v % 4) {
 233 -               printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
 234 -               return -ENOEXEC;
 235 -       }
 236 +       unsigned *tramp = start + *plt_offset;
 237
 238 -       if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 239 -               printk(KERN_ERR
 240 -                      "module %s: relocation overflow\n",
 241 -                      me->name);
 242 -               return -ENOEXEC;
 243 -       }
 244 +       *plt_offset += 4 * sizeof(int);
 245 +
 246 +       /* adjust carry for addiu */
 247 +       if (v & 0x00008000)
 248 +               v += 0x10000;
 249 +
 250 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 251 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 252 +       tramp[2] = 0x03200008;                  /* jr t9 */
 253 +       tramp[3] = 0x00000000;                  /* nop */
 254
 255 -       *location = (*location & ~0x03ffffff) |
 256 -                   ((*location + (v >> 2)) & 0x03ffffff);
 257 +       return (Elf_Addr) tramp;
 258 +}
 259 +
 260 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 261 +{
 262 +       if (location >= me->module_core &&
 263 +           location < me->module_core + me->core_size)
 264 +               return add_plt_entry_to(&me->arch.core_plt_offset,
 265 +                               me->arch.plt_tbl, v);
 266 +
 267 +       if (location >= me->module_init &&
 268 +           location < me->module_init + me->init_size)
 269 +               return add_plt_entry_to(&me->arch.init_plt_offset,
 270 +                               me->arch.plt_tbl, v);
 271
 272         return 0;
 273  }
 274
 275 -static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 276 +static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
 277  {
 278         if (v % 4) {
 279                 printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
 280 @@ -125,17 +296,31 @@
 281         }
 282
 283         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 284 -               printk(KERN_ERR
 285 +           v = add_plt_entry(me, location, v + (ofs << 2));
 286 +               if (!v) {
 287 +                       printk(KERN_ERR
 288                        "module %s: relocation overflow\n",
 289                        me->name);
 290 -               return -ENOEXEC;
 291 +                       return -ENOEXEC;
 292 +               }
 293 +               ofs = 0;
 294         }
 295
 296 -       *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
 297 +       *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
 298
 299         return 0;
 300  }
 301
 302 +static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 303 +{
 304 +       return set_r_mips_26(me, location, *location & 0x03ffffff, v);
 305 +}
 306 +
 307 +static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 308 +{
 309 +       return set_r_mips_26(me, location, 0, v);
 310 +}
 311 +
 312  static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 313  {
 314         struct mips_hi16 *n;
 315 @@ -400,11 +585,23 @@
 316                 list_add(&me->arch.dbe_list, &dbe_list);
 317                 spin_unlock_irq(&dbe_lock);
 318         }
 319 +
 320 +       /* Get rid of the fixup trampoline if we're running the module
 321 +        * from physically mapped address space */
 322 +       if (me->arch.core_plt_offset == 0 &&
 323 +           me->arch.init_plt_offset == me->arch.core_plt_size &&
 324 +           is_phys_addr(me->module_core)) {
 325 +               kfree(me->arch.plt_tbl);
 326 +               me->arch.plt_tbl = NULL;
 327 +       }
 328 +
 329         return 0;
 330  }
 331
 332  void module_arch_cleanup(struct module *mod)
 333  {
 334 +       if (mod->arch.plt_tbl)
 335 +               kfree(mod->arch.plt_tbl);
 336         spin_lock_irq(&dbe_lock);
 337         list_del(&mod->arch.dbe_list);
 338         spin_unlock_irq(&dbe_lock);