target/linux/generic/patches-4.4/305-mips_module_reloc.patch

   1 --- a/arch/mips/Makefile
   2 +++ b/arch/mips/Makefile
   3 @@ -90,8 +90,13 @@ 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 +KBUILD_AFLAGS_MODULE           += -mno-long-calls
  12 +KBUILD_CFLAGS_MODULE           += -mno-long-calls
  13 +endif
  14
  15  ifndef CONFIG_FUNCTION_TRACER
  16  KBUILD_CFLAGS_KERNEL           += -ffunction-sections -fdata-sections
  17 --- a/arch/mips/include/asm/module.h
  18 +++ b/arch/mips/include/asm/module.h
  19 @@ -11,6 +11,11 @@ struct mod_arch_specific {
  20         const struct exception_table_entry *dbe_start;
  21         const struct exception_table_entry *dbe_end;
  22         struct mips_hi16 *r_mips_hi16_list;
  23 +
  24 +       void *phys_plt_tbl;
  25 +       void *virt_plt_tbl;
  26 +       unsigned int phys_plt_offset;
  27 +       unsigned int virt_plt_offset;
  28  };
  29
  30  typedef uint8_t Elf64_Byte;            /* Type for a 8-bit quantity.  */
  31 --- a/arch/mips/kernel/module.c
  32 +++ b/arch/mips/kernel/module.c
  33 @@ -43,14 +43,221 @@ struct mips_hi16 {
  34  static LIST_HEAD(dbe_list);
  35  static DEFINE_SPINLOCK(dbe_lock);
  36
  37 -#ifdef MODULE_START
  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 +       /* mark all pages except for the last one */
 130 +       for (p = page; p + 1 < page + (size >> PAGE_SHIFT); ++p)
 131 +               set_bit(PG_owner_priv_1, &p->flags);
 132 +
 133 +       for (p = page + (size >> PAGE_SHIFT); p < page + (1 << order); ++p)
 134 +               __free_page(p);
 135 +
 136 +       return page_address(page);
 137 +}
 138 +#endif
 139 +
 140 +static void free_phys(void *ptr)
 141 +{
 142 +       struct page *page;
 143 +       bool free;
 144 +
 145 +       page = virt_to_page(ptr);
 146 +       do {
 147 +               free = test_and_clear_bit(PG_owner_priv_1, &page->flags);
 148 +               __free_page(page);
 149 +               page++;
 150 +       } while (free);
 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, 0, 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_memfree(void *module_region)
 189 +{
 190 +       if (is_phys_addr(module_region))
 191 +               free_phys(module_region);
 192 +       else
 193 +               vfree(module_region);
 194 +}
 195 +
 196 +static void *__module_alloc(int size, bool phys)
 197 +{
 198 +       void *ptr;
 199 +
 200 +       if (phys)
 201 +               ptr = kmalloc(size, GFP_KERNEL);
 202 +       else
 203 +               ptr = vmalloc(size);
 204 +       return ptr;
 205 +}
 206 +
 207 +static void __module_free(void *ptr)
 208 +{
 209 +       if (is_phys_addr(ptr))
 210 +               kfree(ptr);
 211 +       else
 212 +               vfree(ptr);
 213 +}
 214 +
 215 +int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
 216 +                             char *secstrings, struct module *mod)
 217 +{
 218 +       unsigned int symindex = 0;
 219 +       unsigned int core_size, init_size;
 220 +       int i;
 221 +
 222 +       mod->arch.phys_plt_offset = 0;
 223 +       mod->arch.virt_plt_offset = 0;
 224 +       mod->arch.phys_plt_tbl = NULL;
 225 +       mod->arch.virt_plt_tbl = NULL;
 226 +
 227 +       if (IS_ENABLED(CONFIG_64BIT))
 228 +               return 0;
 229 +
 230 +       for (i = 1; i < hdr->e_shnum; i++)
 231 +               if (sechdrs[i].sh_type == SHT_SYMTAB)
 232 +                       symindex = i;
 233 +
 234 +       core_size = get_plt_size(hdr, sechdrs, secstrings, symindex, false);
 235 +       init_size = get_plt_size(hdr, sechdrs, secstrings, symindex, true);
 236 +
 237 +       if ((core_size + init_size) == 0)
 238 +               return 0;
 239 +
 240 +       mod->arch.phys_plt_tbl = __module_alloc(core_size + init_size, 1);
 241 +       if (!mod->arch.phys_plt_tbl)
 242 +               return -ENOMEM;
 243 +
 244 +       mod->arch.virt_plt_tbl = __module_alloc(core_size + init_size, 0);
 245 +       if (!mod->arch.virt_plt_tbl) {
 246 +               __module_free(mod->arch.phys_plt_tbl);
 247 +               mod->arch.phys_plt_tbl = NULL;
 248 +               return -ENOMEM;
 249 +       }
 250 +
 251 +       return 0;
 252 +}
 253
 254  int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
 255  {
 256 @@ -64,8 +271,39 @@ static int apply_r_mips_32_rel(struct mo
 257         return 0;
 258  }
 259
 260 +static Elf_Addr add_plt_entry_to(unsigned *plt_offset,
 261 +                                void *start, Elf_Addr v)
 262 +{
 263 +       unsigned *tramp = start + *plt_offset;
 264 +       *plt_offset += 4 * sizeof(int);
 265 +
 266 +       /* adjust carry for addiu */
 267 +       if (v & 0x00008000)
 268 +               v += 0x10000;
 269 +
 270 +       tramp[0] = 0x3c190000 | (v >> 16);      /* lui t9, hi16 */
 271 +       tramp[1] = 0x27390000 | (v & 0xffff);   /* addiu t9, t9, lo16 */
 272 +       tramp[2] = 0x03200008;                  /* jr t9 */
 273 +       tramp[3] = 0x00000000;                  /* nop */
 274 +
 275 +       return (Elf_Addr) tramp;
 276 +}
 277 +
 278 +static Elf_Addr add_plt_entry(struct module *me, void *location, Elf_Addr v)
 279 +{
 280 +       if (is_phys_addr(location))
 281 +               return add_plt_entry_to(&me->arch.phys_plt_offset,
 282 +                               me->arch.phys_plt_tbl, v);
 283 +       else
 284 +               return add_plt_entry_to(&me->arch.virt_plt_offset,
 285 +                               me->arch.virt_plt_tbl, v);
 286 +
 287 +}
 288 +
 289  static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
 290  {
 291 +       u32 ofs = *location & 0x03ffffff;
 292 +
 293         if (v % 4) {
 294                 pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
 295                        me->name);
 296 @@ -73,14 +311,17 @@ static int apply_r_mips_26_rel(struct mo
 297         }
 298
 299         if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 300 -               printk(KERN_ERR
 301 -                      "module %s: relocation overflow\n",
 302 -                      me->name);
 303 -               return -ENOEXEC;
 304 +               v = add_plt_entry(me, location, v + (ofs << 2));
 305 +               if (!v) {
 306 +                       printk(KERN_ERR
 307 +                               "module %s: relocation overflow\n", me->name);
 308 +                       return -ENOEXEC;
 309 +               }
 310 +               ofs = 0;
 311         }
 312
 313         *location = (*location & ~0x03ffffff) |
 314 -                   ((*location + (v >> 2)) & 0x03ffffff);
 315 +                   ((ofs + (v >> 2)) & 0x03ffffff);
 316
 317         return 0;
 318  }
 319 @@ -287,9 +528,36 @@ int module_finalize(const Elf_Ehdr *hdr,
 320                 list_add(&me->arch.dbe_list, &dbe_list);
 321                 spin_unlock_irq(&dbe_lock);
 322         }
 323 +
 324 +       /* Get rid of the fixup trampoline if we're running the module
 325 +        * from physically mapped address space */
 326 +       if (me->arch.phys_plt_offset == 0) {
 327 +               __module_free(me->arch.phys_plt_tbl);
 328 +               me->arch.phys_plt_tbl = NULL;
 329 +       }
 330 +       if (me->arch.virt_plt_offset == 0) {
 331 +               __module_free(me->arch.virt_plt_tbl);
 332 +               me->arch.virt_plt_tbl = NULL;
 333 +       }
 334 +
 335         return 0;
 336  }
 337
 338 +void module_arch_freeing_init(struct module *mod)
 339 +{
 340 +       if (mod->state == MODULE_STATE_LIVE)
 341 +               return;
 342 +
 343 +       if (mod->arch.phys_plt_tbl) {
 344 +               __module_free(mod->arch.phys_plt_tbl);
 345 +               mod->arch.phys_plt_tbl = NULL;
 346 +       }
 347 +       if (mod->arch.virt_plt_tbl) {
 348 +               __module_free(mod->arch.virt_plt_tbl);
 349 +               mod->arch.virt_plt_tbl = NULL;
 350 +       }
 351 +}
 352 +
 353  void module_arch_cleanup(struct module *mod)
 354  {
 355         spin_lock_irq(&dbe_lock);