target/linux/generic-2.6/patches-2.6.28/026-mips_module_reloc.patch

   1 --- a/arch/mips/Makefile
   2 +++ b/arch/mips/Makefile
   3 @@ -82,7 +82,7 @@ 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 +43,114 @@ 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 Elf32_Ehdr *hdr, const Elf32_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 +static void *alloc_phys(unsigned long size)
 107 +{
 108 +       unsigned order;
 109 +       struct page *page;
 110 +       struct page *p;
 111 +
 112 +       size = PAGE_ALIGN(size);
 113 +       order = get_order(size);
 114 +
 115 +       page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
 116 +                       __GFP_THISNODE, order);
 117 +       if (!page)
 118 +               return NULL;
 119 +
 120 +       split_page(page, order);
 121 +
 122 +       for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
 123 +               __free_page(p);
 124 +
 125 +       return page_address(page);
 126 +}
 127 +
 128 +static void free_phys(void *ptr, unsigned long size)
 129 +{
 130 +       struct page *page;
 131 +       struct page *end;
 132 +
 133 +       page = virt_to_page(ptr);
 134 +       end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
 135 +
 136 +       for (; page < end; ++page)
 137 +               __free_page(page);
 138 +}
 139 +
 140  void *module_alloc(unsigned long size)
 141  {
 142  #ifdef MODULE_START
 143 @@ -58,16 +166,41 @@ void *module_alloc(unsigned long size)
 144
 145         return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL);
 146  #else
 147 +       void *ptr;
 148 +
 149         if (size == 0)
 150                 return NULL;
 151 -       return vmalloc(size);
 152 +
 153 +       ptr = alloc_phys(size);
 154 +
 155 +       /* If we failed to allocate physically contiguous memory,
 156 +        * fall back to regular vmalloc. The module loader code will
 157 +        * create jump tables to handle long jumps */
 158 +       if (!ptr)
 159 +               return vmalloc(size);
 160 +
 161 +       return ptr;
 162  #endif
 163  }
 164
 165 +static inline bool is_phys_addr(void *ptr)
 166 +{
 167 +       return (KSEGX(ptr) == KSEG0);
 168 +}
 169 +
 170  /* Free memory returned from module_alloc */
 171  void module_free(struct module *mod, void *module_region)
 172  {
 173 -       vfree(module_region);
 174 +       if (is_phys_addr(module_region)) {
 175 +               if (mod->module_init == module_region)
 176 +                       free_phys(module_region, mod->init_size);
 177 +               else if (mod->module_core == module_region)
 178 +                       free_phys(module_region, mod->core_size);
 179 +               else
 180 +                       BUG();
 181 +       } else {
 182 +               vfree(module_region);
 183 +       }
 184         /* FIXME: If module_region == mod->init_region, trim exception
 185             table entries. */
 186  }
 187 @@ -75,6 +208,24 @@ void module_free(struct module *mod, voi
 188  int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 189                               char *secstrings, struct module *mod)
 190  {
 191 +       unsigned int symindex = 0;
 192 +       unsigned int core_size, init_size;
 193 +       int i;
 194 +
 195 +       for (i = 1; i < hdr->e_shnum; i++)
 196 +               if (sechdrs[i].sh_type == SHT_SYMTAB)
 197 +                       symindex = i;
 198 +
 199 +       core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
 200 +       init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
 201 +
 202 +       mod->arch.core_plt_offset = 0;
 203 +       mod->arch.core_plt_size = core_size;
 204 +       mod->arch.init_plt_offset = core_size;
 205 +       mod->arch.plt_tbl = kmalloc(core_size + init_size, GFP_KERNEL);
 206 +       if (!mod->arch.plt_tbl)
 207 +               return -ENOMEM;
 208 +
 209         return 0;
 210  }
 211
 212 @@ -97,27 +248,41 @@ static int apply_r_mips_32_rela(struct m
 213         return 0;
 214  }
 215
 216 -static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 217 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 218 +                                void *start, Elf_Addr v)
 219  {
 220 -       if (v % 4) {
 221 -               printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
 222 -               return -ENOEXEC;
 223 -       }
 224 +       unsigned *tramp = start + *plt_offset;
 225
 226 -       if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 227 -               printk(KERN_ERR
 228 -                      "module %s: relocation overflow\n",
 229 -                      me->name);
 230 -               return -ENOEXEC;
 231 -       }
 232 +       *plt_offset += 4 * sizeof(int);
 233 +
 234 +       /* adjust carry for addiu */
 235 +       if (v & 0x00008000)
 236 +               v += 0x10000;
 237
 238 -       *location = (*location & ~0x03ffffff) |
 239 -                   ((*location + (v >> 2)) & 0x03ffffff);
 240 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 241 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 242 +       tramp[2] = 0x03200008;                  /* jr t9 */
 243 +       tramp[3] = 0x00000000;                  /* nop */
 244 +
 245 +       return (Elf_Addr) tramp;
 246 +}
 247 +
 248 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 249 +{
 250 +       if (location >= me->module_core &&
 251 +           location < me->module_core + me->core_size)
 252 +               return add_plt_entry_to(&me->arch.core_plt_offset,
 253 +                               me->arch.plt_tbl, v);
 254 +
 255 +       if (location >= me->module_init &&
 256 +           location < me->module_init + me->init_size)
 257 +               return add_plt_entry_to(&me->arch.init_plt_offset,
 258 +                               me->arch.plt_tbl, v);
 259
 260         return 0;
 261  }
 262
 263 -static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 264 +static int set_r_mips_26(struct module *me, u32 *location, u32 ofs, Elf_Addr v)
 265  {
 266         if (v % 4) {
 267                 printk(KERN_ERR "module %s: dangerous relocation\n", me->name);
 268 @@ -125,17 +290,31 @@ static int apply_r_mips_26_rela(struct m
 269         }
 270
 271         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 272 -               printk(KERN_ERR
 273 +           v = add_plt_entry(me, location, v + (ofs << 2));
 274 +               if (!v) {
 275 +                       printk(KERN_ERR
 276                        "module %s: relocation overflow\n",
 277                        me->name);
 278 -               return -ENOEXEC;
 279 +                       return -ENOEXEC;
 280 +               }
 281 +               ofs = 0;
 282         }
 283
 284 -       *location = (*location & ~0x03ffffff) | ((v >> 2) & 0x03ffffff);
 285 +       *location = (*location & ~0x03ffffff) | ((ofs + (v >> 2)) & 0x03ffffff);
 286
 287         return 0;
 288  }
 289
 290 +static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 291 +{
 292 +       return set_r_mips_26(me, location, *location & 0x03ffffff, v);
 293 +}
 294 +
 295 +static int apply_r_mips_26_rela(struct module *me, u32 *location, Elf_Addr v)
 296 +{
 297 +       return set_r_mips_26(me, location, 0, v);
 298 +}
 299 +
 300  static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 301  {
 302         struct mips_hi16 *n;
 303 @@ -400,11 +579,23 @@ int module_finalize(const Elf_Ehdr *hdr,
 304                 list_add(&me->arch.dbe_list, &dbe_list);
 305                 spin_unlock_irq(&dbe_lock);
 306         }
 307 +
 308 +       /* Get rid of the fixup trampoline if we're running the module
 309 +        * from physically mapped address space */
 310 +       if (me->arch.core_plt_offset == 0 &&
 311 +           me->arch.init_plt_offset == me->arch.core_plt_size &&
 312 +           is_phys_addr(me->module_core)) {
 313 +               kfree(me->arch.plt_tbl);
 314 +               me->arch.plt_tbl = NULL;
 315 +       }
 316 +
 317         return 0;
 318  }
 319
 320  void module_arch_cleanup(struct module *mod)
 321  {
 322 +       if (mod->arch.plt_tbl)
 323 +               kfree(mod->arch.plt_tbl);
 324         spin_lock_irq(&dbe_lock);
 325         list_del(&mod->arch.dbe_list);
 326         spin_unlock_irq(&dbe_lock);