target/linux/generic/pending-3.18/305-mips_module_reloc.patch

   1 --- a/arch/mips/Makefile
   2 +++ b/arch/mips/Makefile
   3 @@ -90,8 +90,18 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
   4  cflags-y                       += -G 0 -mno-abicalls -fno-pic -pipe -mno-branch-likely
   5  cflags-y                       += -msoft-float
   6  LDFLAGS_vmlinux                        += -G 0 -static -n -nostdlib --gc-sections
   7 +ifdef CONFIG_64BIT
   8  KBUILD_AFLAGS_MODULE           += -mlong-calls
   9  KBUILD_CFLAGS_MODULE           += -mlong-calls
  10 +else
  11 +  ifdef CONFIG_DYNAMIC_FTRACE
  12 +    KBUILD_AFLAGS_MODULE       += -mlong-calls
  13 +    KBUILD_CFLAGS_MODULE       += -mlong-calls
  14 +  else
  15 +    KBUILD_AFLAGS_MODULE       += -mno-long-calls
  16 +    KBUILD_CFLAGS_MODULE       += -mno-long-calls
  17 +  endif
  18 +endif
  19
  20  ifndef CONFIG_FUNCTION_TRACER
  21  KBUILD_CFLAGS_KERNEL           += -ffunction-sections -fdata-sections
  22 --- a/arch/mips/include/asm/module.h
  23 +++ b/arch/mips/include/asm/module.h
  24 @@ -11,6 +11,11 @@ struct mod_arch_specific {
  25         const struct exception_table_entry *dbe_start;
  26         const struct exception_table_entry *dbe_end;
  27         struct mips_hi16 *r_mips_hi16_list;
  28 +
  29 +       void *phys_plt_tbl;
  30 +       void *virt_plt_tbl;
  31 +       unsigned int phys_plt_offset;
  32 +       unsigned int virt_plt_offset;
  33  };
  34
  35  typedef uint8_t Elf64_Byte;            /* Type for a 8-bit quantity.  */
  36 --- a/arch/mips/kernel/module.c
  37 +++ b/arch/mips/kernel/module.c
  38 @@ -43,14 +43,222 @@ struct mips_hi16 {
  39  static LIST_HEAD(dbe_list);
  40  static DEFINE_SPINLOCK(dbe_lock);
  41
  42 -#ifdef MODULE_START
  43 +/*
  44 + * Get the potential max trampolines size required of the init and
  45 + * non-init sections. Only used if we cannot find enough contiguous
  46 + * physically mapped memory to put the module into.
  47 + */
  48 +static unsigned int
  49 +get_plt_size(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
  50 +             const char *secstrings, unsigned int symindex, bool is_init)
  51 +{
  52 +       unsigned long ret = 0;
  53 +       unsigned int i, j;
  54 +       Elf_Sym *syms;
  55 +
  56 +       /* Everything marked ALLOC (this includes the exported symbols) */
  57 +       for (i = 1; i < hdr->e_shnum; ++i) {
  58 +               unsigned int info = sechdrs[i].sh_info;
  59 +
  60 +               if (sechdrs[i].sh_type != SHT_REL
  61 +                   && sechdrs[i].sh_type != SHT_RELA)
  62 +                       continue;
  63 +
  64 +               /* Not a valid relocation section? */
  65 +               if (info >= hdr->e_shnum)
  66 +                       continue;
  67 +
  68 +               /* Don't bother with non-allocated sections */
  69 +               if (!(sechdrs[info].sh_flags & SHF_ALLOC))
  70 +                       continue;
  71 +
  72 +               /* If it's called *.init*, and we're not init, we're
  73 +                   not interested */
  74 +               if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
  75 +                   != is_init)
  76 +                       continue;
  77 +
  78 +               syms = (Elf_Sym *) sechdrs[symindex].sh_addr;
  79 +               if (sechdrs[i].sh_type == SHT_REL) {
  80 +                       Elf_Mips_Rel *rel = (void *) sechdrs[i].sh_addr;
  81 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rel);
  82 +
  83 +                       for (j = 0; j < size; ++j) {
  84 +                               Elf_Sym *sym;
  85 +
  86 +                               if (ELF_MIPS_R_TYPE(rel[j]) != R_MIPS_26)
  87 +                                       continue;
  88 +
  89 +                               sym = syms + ELF_MIPS_R_SYM(rel[j]);
  90 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
  91 +                                       continue;
  92 +
  93 +                               ret += 4 * sizeof(int);
  94 +                       }
  95 +               } else {
  96 +                       Elf_Mips_Rela *rela = (void *) sechdrs[i].sh_addr;
  97 +                       unsigned int size = sechdrs[i].sh_size / sizeof(*rela);
  98 +
  99 +                       for (j = 0; j < size; ++j) {
 100 +                               Elf_Sym *sym;
 101 +
 102 +                               if (ELF_MIPS_R_TYPE(rela[j]) != R_MIPS_26)
 103 +                                       continue;
 104 +
 105 +                               sym = syms + ELF_MIPS_R_SYM(rela[j]);
 106 +                               if (!is_init && sym->st_shndx != SHN_UNDEF)
 107 +                                       continue;
 108 +
 109 +                               ret += 4 * sizeof(int);
 110 +                       }
 111 +               }
 112 +       }
 113 +
 114 +       return ret;
 115 +}
 116 +
 117 +#ifndef MODULE_START
 118 +static void *alloc_phys(unsigned long size)
 119 +{
 120 +       unsigned order;
 121 +       struct page *page;
 122 +       struct page *p;
 123 +
 124 +       size = PAGE_ALIGN(size);
 125 +       order = get_order(size);
 126 +
 127 +       page = alloc_pages(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN |
 128 +                       __GFP_THISNODE, order);
 129 +       if (!page)
 130 +               return NULL;
 131 +
 132 +       split_page(page, order);
 133 +
 134 +       for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
 135 +               __free_page(p);
 136 +
 137 +       return page_address(page);
 138 +}
 139 +#endif
 140 +
 141 +static void free_phys(void *ptr, unsigned long size)
 142 +{
 143 +       struct page *page;
 144 +       struct page *end;
 145 +
 146 +       page = virt_to_page(ptr);
 147 +       end = page + (PAGE_ALIGN(size) >> PAGE_SHIFT);
 148 +
 149 +       for (; page < end; ++page)
 150 +               __free_page(page);
 151 +}
 152 +
 153 +
 154  void *module_alloc(unsigned long size)
 155  {
 156 +#ifdef MODULE_START
 157         return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
 158                                 GFP_KERNEL, PAGE_KERNEL, NUMA_NO_NODE,
 159                                 __builtin_return_address(0));
 160 +#else
 161 +       void *ptr;
 162 +
 163 +       if (size == 0)
 164 +               return NULL;
 165 +
 166 +       ptr = alloc_phys(size);
 167 +
 168 +       /* If we failed to allocate physically contiguous memory,
 169 +        * fall back to regular vmalloc. The module loader code will
 170 +        * create jump tables to handle long jumps */
 171 +       if (!ptr)
 172 +               return vmalloc(size);
 173 +
 174 +       return ptr;
 175 +#endif
 176  }
 177 +
 178 +static inline bool is_phys_addr(void *ptr)
 179 +{
 180 +#ifdef CONFIG_64BIT
 181 +       return (KSEGX((unsigned long)ptr) == CKSEG0);
 182 +#else
 183 +       return (KSEGX(ptr) == KSEG0);
 184  #endif
 185 +}
 186 +
 187 +/* Free memory returned from module_alloc */
 188 +void module_free(struct module *mod, void *module_region)
 189 +{
 190 +       if (is_phys_addr(module_region)) {
 191 +               if (mod->module_init == module_region)
 192 +                       free_phys(module_region, mod->init_size);
 193 +               else if (mod->module_core == module_region)
 194 +                       free_phys(module_region, mod->core_size);
 195 +               else
 196 +                       BUG();
 197 +       } else {
 198 +               vfree(module_region);
 199 +       }
 200 +}
 201 +
 202 +static void *__module_alloc(int size, bool phys)
 203 +{
 204 +       void *ptr;
 205 +
 206 +       if (phys)
 207 +               ptr = kmalloc(size, GFP_KERNEL);
 208 +       else
 209 +               ptr = vmalloc(size);
 210 +       return ptr;
 211 +}
 212 +
 213 +static void __module_free(void *ptr)
 214 +{
 215 +       if (is_phys_addr(ptr))
 216 +               kfree(ptr);
 217 +       else
 218 +               vfree(ptr);
 219 +}
 220 +
 221 +int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 222 +                             char *secstrings, struct module *mod)
 223 +{
 224 +       unsigned int symindex = 0;
 225 +       unsigned int core_size, init_size;
 226 +       int i;
 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 (IS_ENABLED(CONFIG_64BIT))
 234 +               return 0;
 235 +
 236 +       for (i = 1; i < hdr->e_shnum; i++)
 237 +               if (sechdrs[i].sh_type == SHT_SYMTAB)
 238 +                       symindex = i;
 239 +
 240 +       core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
 241 +       init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
 242 +
 243 +       if ((core_size + init_size) == 0)
 244 +               return 0;
 245 +
 246 +       mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
 247 +       if (!mod->arch.phys_plt_tbl)
 248 +               return -ENOMEM;
 249 +
 250 +       mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
 251 +       if (!mod->arch.virt_plt_tbl) {
 252 +               __module_free(mod->arch.phys_plt_tbl);
 253 +               mod->arch.phys_plt_tbl = NULL;
 254 +               return -ENOMEM;
 255 +       }
 256 +
 257 +       return 0;
 258 +}
 259
 260  int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
 261  {
 262 @@ -64,8 +272,39 @@ static int apply_r_mips_32_rel(struct mo
 263         return 0;
 264  }
 265
 266 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 267 +                                void *start, Elf_Addr v)
 268 +{
 269 +       unsigned *tramp = start + *plt_offset;
 270 +       *plt_offset += 4 * sizeof(int);
 271 +
 272 +       /* adjust carry for addiu */
 273 +       if (v & 0x00008000)
 274 +               v += 0x10000;
 275 +
 276 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 277 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 278 +       tramp[2] = 0x03200008;                  /* jr t9 */
 279 +       tramp[3] = 0x00000000;                  /* nop */
 280 +
 281 +       return (Elf_Addr) tramp;
 282 +}
 283 +
 284 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 285 +{
 286 +       if (is_phys_addr(location))
 287 +               return add_plt_entry_to(&me->arch.phys_plt_offset,
 288 +                               me->arch.phys_plt_tbl, v);
 289 +       else
 290 +               return add_plt_entry_to(&me->arch.virt_plt_offset,
 291 +                               me->arch.virt_plt_tbl, v);
 292 +
 293 +}
 294 +
 295  static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 296  {
 297 +       u32 ofs = *location & 0x03ffffff;
 298 +
 299         if (v % 4) {
 300                 pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
 301                        me->name);
 302 @@ -73,14 +312,17 @@ static int apply_r_mips_26_rel(struct mo
 303         }
 304
 305         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 306 -               printk(KERN_ERR
 307 -                      "module %s: relocation overflow\n",
 308 -                      me->name);
 309 -               return -ENOEXEC;
 310 +               v = add_plt_entry(me, location, v + (ofs << 2));
 311 +               if (!v) {
 312 +                       printk(KERN_ERR
 313 +                               "module %s: relocation overflow\n", me->name);
 314 +                       return -ENOEXEC;
 315 +               }
 316 +               ofs = 0;
 317         }
 318
 319         *location = (*location & ~0x03ffffff) |
 320 -                   ((*location + (v >> 2)) & 0x03ffffff);
 321 +                   ((ofs + (v >> 2)) & 0x03ffffff);
 322
 323         return 0;
 324  }
 325 @@ -287,9 +529,36 @@ int module_finalize(const Elf_Ehdr *hdr,
 326                 list_add(&me->arch.dbe_list, &dbe_list);
 327                 spin_unlock_irq(&dbe_lock);
 328         }
 329 +
 330 +       /* Get rid of the fixup trampoline if we're running the module
 331 +        * from physically mapped address space */
 332 +       if (me->arch.phys_plt_offset == 0) {
 333 +               __module_free(me->arch.phys_plt_tbl);
 334 +               me->arch.phys_plt_tbl = NULL;
 335 +       }
 336 +       if (me->arch.virt_plt_offset == 0) {
 337 +               __module_free(me->arch.virt_plt_tbl);
 338 +               me->arch.virt_plt_tbl = NULL;
 339 +       }
 340 +
 341         return 0;
 342  }
 343
 344 +void module_arch_freeing_init(struct module *mod)
 345 +{
 346 +       if (mod->state == MODULE_STATE_LIVE)
 347 +               return;
 348 +
 349 +       if (mod->arch.phys_plt_tbl) {
 350 +               __module_free(mod->arch.phys_plt_tbl);
 351 +               mod->arch.phys_plt_tbl = NULL;
 352 +       }
 353 +       if (mod->arch.virt_plt_tbl) {
 354 +               __module_free(mod->arch.virt_plt_tbl);
 355 +               mod->arch.virt_plt_tbl = NULL;
 356 +       }
 357 +}
 358 +
 359  void module_arch_cleanup(struct module *mod)
 360  {
 361         spin_lock_irq(&dbe_lock);