Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* binfmt_elf_fdpic.c: FDPIC ELF binary format |
| 2 | * |
| 3 | * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * Derived from binfmt_elf.c |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the License, or (at your option) any later version. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/stat.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/mm.h> |
| 19 | #include <linux/mman.h> |
| 20 | #include <linux/errno.h> |
| 21 | #include <linux/signal.h> |
| 22 | #include <linux/binfmts.h> |
| 23 | #include <linux/string.h> |
| 24 | #include <linux/file.h> |
| 25 | #include <linux/fcntl.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/highmem.h> |
| 28 | #include <linux/personality.h> |
| 29 | #include <linux/ptrace.h> |
| 30 | #include <linux/init.h> |
| 31 | #include <linux/smp_lock.h> |
| 32 | #include <linux/elf.h> |
| 33 | #include <linux/elf-fdpic.h> |
| 34 | #include <linux/elfcore.h> |
| 35 | |
| 36 | #include <asm/uaccess.h> |
| 37 | #include <asm/param.h> |
| 38 | #include <asm/pgalloc.h> |
| 39 | |
| 40 | typedef char *elf_caddr_t; |
| 41 | #ifndef elf_addr_t |
| 42 | #define elf_addr_t unsigned long |
| 43 | #endif |
| 44 | |
| 45 | #if 0 |
| 46 | #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) |
| 47 | #else |
| 48 | #define kdebug(fmt, ...) do {} while(0) |
| 49 | #endif |
| 50 | |
| 51 | MODULE_LICENSE("GPL"); |
| 52 | |
| 53 | static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs); |
| 54 | //static int load_elf_fdpic_library(struct file *); |
| 55 | static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file); |
| 56 | static int elf_fdpic_map_file(struct elf_fdpic_params *params, |
| 57 | struct file *file, |
| 58 | struct mm_struct *mm, |
| 59 | const char *what); |
| 60 | |
| 61 | static int create_elf_fdpic_tables(struct linux_binprm *bprm, |
| 62 | struct mm_struct *mm, |
| 63 | struct elf_fdpic_params *exec_params, |
| 64 | struct elf_fdpic_params *interp_params); |
| 65 | |
| 66 | #ifndef CONFIG_MMU |
| 67 | static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp); |
| 68 | static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params, |
| 69 | struct file *file, |
| 70 | struct mm_struct *mm); |
| 71 | #endif |
| 72 | |
| 73 | static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, |
| 74 | struct file *file, |
| 75 | struct mm_struct *mm); |
| 76 | |
| 77 | static struct linux_binfmt elf_fdpic_format = { |
| 78 | .module = THIS_MODULE, |
| 79 | .load_binary = load_elf_fdpic_binary, |
| 80 | // .load_shlib = load_elf_fdpic_library, |
| 81 | // .core_dump = elf_fdpic_core_dump, |
| 82 | .min_coredump = ELF_EXEC_PAGESIZE, |
| 83 | }; |
| 84 | |
| 85 | static int __init init_elf_fdpic_binfmt(void) { return register_binfmt(&elf_fdpic_format); } |
| 86 | static void __exit exit_elf_fdpic_binfmt(void) { unregister_binfmt(&elf_fdpic_format); } |
| 87 | |
| 88 | module_init(init_elf_fdpic_binfmt) |
| 89 | module_exit(exit_elf_fdpic_binfmt) |
| 90 | |
| 91 | static int is_elf_fdpic(struct elfhdr *hdr, struct file *file) |
| 92 | { |
| 93 | if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) |
| 94 | return 0; |
| 95 | if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) |
| 96 | return 0; |
| 97 | if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr)) |
| 98 | return 0; |
| 99 | if (!file->f_op || !file->f_op->mmap) |
| 100 | return 0; |
| 101 | return 1; |
| 102 | } |
| 103 | |
| 104 | /*****************************************************************************/ |
| 105 | /* |
| 106 | * read the program headers table into memory |
| 107 | */ |
| 108 | static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file) |
| 109 | { |
| 110 | struct elf32_phdr *phdr; |
| 111 | unsigned long size; |
| 112 | int retval, loop; |
| 113 | |
| 114 | if (params->hdr.e_phentsize != sizeof(struct elf_phdr)) |
| 115 | return -ENOMEM; |
| 116 | if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr)) |
| 117 | return -ENOMEM; |
| 118 | |
| 119 | size = params->hdr.e_phnum * sizeof(struct elf_phdr); |
| 120 | params->phdrs = kmalloc(size, GFP_KERNEL); |
| 121 | if (!params->phdrs) |
| 122 | return -ENOMEM; |
| 123 | |
| 124 | retval = kernel_read(file, params->hdr.e_phoff, (char *) params->phdrs, size); |
| 125 | if (retval < 0) |
| 126 | return retval; |
| 127 | |
| 128 | /* determine stack size for this binary */ |
| 129 | phdr = params->phdrs; |
| 130 | for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { |
| 131 | if (phdr->p_type != PT_GNU_STACK) |
| 132 | continue; |
| 133 | |
| 134 | if (phdr->p_flags & PF_X) |
| 135 | params->flags |= ELF_FDPIC_FLAG_EXEC_STACK; |
| 136 | else |
| 137 | params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK; |
| 138 | |
| 139 | params->stack_size = phdr->p_memsz; |
| 140 | break; |
| 141 | } |
| 142 | |
| 143 | return 0; |
| 144 | } /* end elf_fdpic_fetch_phdrs() */ |
| 145 | |
| 146 | /*****************************************************************************/ |
| 147 | /* |
| 148 | * load an fdpic binary into various bits of memory |
| 149 | */ |
| 150 | static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs) |
| 151 | { |
| 152 | struct elf_fdpic_params exec_params, interp_params; |
| 153 | struct elf_phdr *phdr; |
| 154 | unsigned long stack_size; |
| 155 | struct file *interpreter = NULL; /* to shut gcc up */ |
| 156 | char *interpreter_name = NULL; |
| 157 | int executable_stack; |
| 158 | int retval, i; |
| 159 | |
| 160 | memset(&exec_params, 0, sizeof(exec_params)); |
| 161 | memset(&interp_params, 0, sizeof(interp_params)); |
| 162 | |
| 163 | exec_params.hdr = *(struct elfhdr *) bprm->buf; |
| 164 | exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE; |
| 165 | |
| 166 | /* check that this is a binary we know how to deal with */ |
| 167 | retval = -ENOEXEC; |
| 168 | if (!is_elf_fdpic(&exec_params.hdr, bprm->file)) |
| 169 | goto error; |
| 170 | |
| 171 | /* read the program header table */ |
| 172 | retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file); |
| 173 | if (retval < 0) |
| 174 | goto error; |
| 175 | |
| 176 | /* scan for a program header that specifies an interpreter */ |
| 177 | phdr = exec_params.phdrs; |
| 178 | |
| 179 | for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) { |
| 180 | switch (phdr->p_type) { |
| 181 | case PT_INTERP: |
| 182 | retval = -ENOMEM; |
| 183 | if (phdr->p_filesz > PATH_MAX) |
| 184 | goto error; |
| 185 | retval = -ENOENT; |
| 186 | if (phdr->p_filesz < 2) |
| 187 | goto error; |
| 188 | |
| 189 | /* read the name of the interpreter into memory */ |
| 190 | interpreter_name = (char *) kmalloc(phdr->p_filesz, GFP_KERNEL); |
| 191 | if (!interpreter_name) |
| 192 | goto error; |
| 193 | |
| 194 | retval = kernel_read(bprm->file, |
| 195 | phdr->p_offset, |
| 196 | interpreter_name, |
| 197 | phdr->p_filesz); |
| 198 | if (retval < 0) |
| 199 | goto error; |
| 200 | |
| 201 | retval = -ENOENT; |
| 202 | if (interpreter_name[phdr->p_filesz - 1] != '\0') |
| 203 | goto error; |
| 204 | |
| 205 | kdebug("Using ELF interpreter %s", interpreter_name); |
| 206 | |
| 207 | /* replace the program with the interpreter */ |
| 208 | interpreter = open_exec(interpreter_name); |
| 209 | retval = PTR_ERR(interpreter); |
| 210 | if (IS_ERR(interpreter)) { |
| 211 | interpreter = NULL; |
| 212 | goto error; |
| 213 | } |
| 214 | |
| 215 | retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE); |
| 216 | if (retval < 0) |
| 217 | goto error; |
| 218 | |
| 219 | interp_params.hdr = *((struct elfhdr *) bprm->buf); |
| 220 | break; |
| 221 | |
| 222 | case PT_LOAD: |
| 223 | #ifdef CONFIG_MMU |
| 224 | if (exec_params.load_addr == 0) |
| 225 | exec_params.load_addr = phdr->p_vaddr; |
| 226 | #endif |
| 227 | break; |
| 228 | } |
| 229 | |
| 230 | } |
| 231 | |
| 232 | if (elf_check_const_displacement(&exec_params.hdr)) |
| 233 | exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; |
| 234 | |
| 235 | /* perform insanity checks on the interpreter */ |
| 236 | if (interpreter_name) { |
| 237 | retval = -ELIBBAD; |
| 238 | if (!is_elf_fdpic(&interp_params.hdr, interpreter)) |
| 239 | goto error; |
| 240 | |
| 241 | interp_params.flags = ELF_FDPIC_FLAG_PRESENT; |
| 242 | |
| 243 | /* read the interpreter's program header table */ |
| 244 | retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter); |
| 245 | if (retval < 0) |
| 246 | goto error; |
| 247 | } |
| 248 | |
| 249 | stack_size = exec_params.stack_size; |
| 250 | if (stack_size < interp_params.stack_size) |
| 251 | stack_size = interp_params.stack_size; |
| 252 | |
| 253 | if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) |
| 254 | executable_stack = EXSTACK_ENABLE_X; |
| 255 | else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) |
| 256 | executable_stack = EXSTACK_DISABLE_X; |
| 257 | else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK) |
| 258 | executable_stack = EXSTACK_ENABLE_X; |
| 259 | else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK) |
| 260 | executable_stack = EXSTACK_DISABLE_X; |
| 261 | else |
| 262 | executable_stack = EXSTACK_DEFAULT; |
| 263 | |
| 264 | retval = -ENOEXEC; |
| 265 | if (stack_size == 0) |
| 266 | goto error; |
| 267 | |
| 268 | if (elf_check_const_displacement(&interp_params.hdr)) |
| 269 | interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP; |
| 270 | |
| 271 | /* flush all traces of the currently running executable */ |
| 272 | retval = flush_old_exec(bprm); |
| 273 | if (retval) |
| 274 | goto error; |
| 275 | |
| 276 | /* there's now no turning back... the old userspace image is dead, |
| 277 | * defunct, deceased, etc. after this point we have to exit via |
| 278 | * error_kill */ |
| 279 | set_personality(PER_LINUX_FDPIC); |
| 280 | set_binfmt(&elf_fdpic_format); |
| 281 | |
| 282 | current->mm->start_code = 0; |
| 283 | current->mm->end_code = 0; |
| 284 | current->mm->start_stack = 0; |
| 285 | current->mm->start_data = 0; |
| 286 | current->mm->end_data = 0; |
| 287 | current->mm->context.exec_fdpic_loadmap = 0; |
| 288 | current->mm->context.interp_fdpic_loadmap = 0; |
| 289 | |
| 290 | current->flags &= ~PF_FORKNOEXEC; |
| 291 | |
| 292 | #ifdef CONFIG_MMU |
| 293 | elf_fdpic_arch_lay_out_mm(&exec_params, |
| 294 | &interp_params, |
| 295 | ¤t->mm->start_stack, |
| 296 | ¤t->mm->start_brk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | retval = setup_arg_pages(bprm, current->mm->start_stack, executable_stack); |
| 299 | if (retval < 0) { |
| 300 | send_sig(SIGKILL, current, 0); |
| 301 | goto error_kill; |
| 302 | } |
| 303 | #endif |
| 304 | |
| 305 | /* load the executable and interpreter into memory */ |
| 306 | retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, "executable"); |
| 307 | if (retval < 0) |
| 308 | goto error_kill; |
| 309 | |
| 310 | if (interpreter_name) { |
| 311 | retval = elf_fdpic_map_file(&interp_params, interpreter, |
| 312 | current->mm, "interpreter"); |
| 313 | if (retval < 0) { |
| 314 | printk(KERN_ERR "Unable to load interpreter\n"); |
| 315 | goto error_kill; |
| 316 | } |
| 317 | |
| 318 | allow_write_access(interpreter); |
| 319 | fput(interpreter); |
| 320 | interpreter = NULL; |
| 321 | } |
| 322 | |
| 323 | #ifdef CONFIG_MMU |
| 324 | if (!current->mm->start_brk) |
| 325 | current->mm->start_brk = current->mm->end_data; |
| 326 | |
| 327 | current->mm->brk = current->mm->start_brk = PAGE_ALIGN(current->mm->start_brk); |
| 328 | |
| 329 | #else |
| 330 | /* create a stack and brk area big enough for everyone |
| 331 | * - the brk heap starts at the bottom and works up |
| 332 | * - the stack starts at the top and works down |
| 333 | */ |
| 334 | stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK; |
| 335 | if (stack_size < PAGE_SIZE * 2) |
| 336 | stack_size = PAGE_SIZE * 2; |
| 337 | |
| 338 | down_write(¤t->mm->mmap_sem); |
| 339 | current->mm->start_brk = do_mmap(NULL, |
| 340 | 0, |
| 341 | stack_size, |
| 342 | PROT_READ | PROT_WRITE | PROT_EXEC, |
| 343 | MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN, |
| 344 | 0); |
| 345 | |
| 346 | if (IS_ERR((void *) current->mm->start_brk)) { |
| 347 | up_write(¤t->mm->mmap_sem); |
| 348 | retval = current->mm->start_brk; |
| 349 | current->mm->start_brk = 0; |
| 350 | goto error_kill; |
| 351 | } |
| 352 | |
| 353 | if (do_mremap(current->mm->start_brk, |
| 354 | stack_size, |
| 355 | ksize((char *) current->mm->start_brk), |
| 356 | 0, 0 |
| 357 | ) == current->mm->start_brk |
| 358 | ) |
| 359 | stack_size = ksize((char *) current->mm->start_brk); |
| 360 | up_write(¤t->mm->mmap_sem); |
| 361 | |
| 362 | current->mm->brk = current->mm->start_brk; |
| 363 | current->mm->context.end_brk = current->mm->start_brk; |
| 364 | current->mm->context.end_brk += (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0; |
| 365 | current->mm->start_stack = current->mm->start_brk + stack_size; |
| 366 | #endif |
| 367 | |
| 368 | compute_creds(bprm); |
| 369 | current->flags &= ~PF_FORKNOEXEC; |
| 370 | if (create_elf_fdpic_tables(bprm, current->mm, &exec_params, &interp_params) < 0) |
| 371 | goto error_kill; |
| 372 | |
| 373 | kdebug("- start_code %lx", (long) current->mm->start_code); |
| 374 | kdebug("- end_code %lx", (long) current->mm->end_code); |
| 375 | kdebug("- start_data %lx", (long) current->mm->start_data); |
| 376 | kdebug("- end_data %lx", (long) current->mm->end_data); |
| 377 | kdebug("- start_brk %lx", (long) current->mm->start_brk); |
| 378 | kdebug("- brk %lx", (long) current->mm->brk); |
| 379 | kdebug("- start_stack %lx", (long) current->mm->start_stack); |
| 380 | |
| 381 | #ifdef ELF_FDPIC_PLAT_INIT |
| 382 | /* |
| 383 | * The ABI may specify that certain registers be set up in special |
| 384 | * ways (on i386 %edx is the address of a DT_FINI function, for |
| 385 | * example. This macro performs whatever initialization to |
| 386 | * the regs structure is required. |
| 387 | */ |
| 388 | ELF_FDPIC_PLAT_INIT(regs, |
| 389 | exec_params.map_addr, |
| 390 | interp_params.map_addr, |
| 391 | interp_params.dynamic_addr ?: exec_params.dynamic_addr |
| 392 | ); |
| 393 | #endif |
| 394 | |
| 395 | /* everything is now ready... get the userspace context ready to roll */ |
| 396 | start_thread(regs, |
| 397 | interp_params.entry_addr ?: exec_params.entry_addr, |
| 398 | current->mm->start_stack); |
| 399 | |
| 400 | if (unlikely(current->ptrace & PT_PTRACED)) { |
| 401 | if (current->ptrace & PT_TRACE_EXEC) |
| 402 | ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP); |
| 403 | else |
| 404 | send_sig(SIGTRAP, current, 0); |
| 405 | } |
| 406 | |
| 407 | retval = 0; |
| 408 | |
| 409 | error: |
| 410 | if (interpreter) { |
| 411 | allow_write_access(interpreter); |
| 412 | fput(interpreter); |
| 413 | } |
| 414 | if (interpreter_name) |
| 415 | kfree(interpreter_name); |
| 416 | if (exec_params.phdrs) |
| 417 | kfree(exec_params.phdrs); |
| 418 | if (exec_params.loadmap) |
| 419 | kfree(exec_params.loadmap); |
| 420 | if (interp_params.phdrs) |
| 421 | kfree(interp_params.phdrs); |
| 422 | if (interp_params.loadmap) |
| 423 | kfree(interp_params.loadmap); |
| 424 | return retval; |
| 425 | |
| 426 | /* unrecoverable error - kill the process */ |
| 427 | error_kill: |
| 428 | send_sig(SIGSEGV, current, 0); |
| 429 | goto error; |
| 430 | |
| 431 | } /* end load_elf_fdpic_binary() */ |
| 432 | |
| 433 | /*****************************************************************************/ |
| 434 | /* |
| 435 | * present useful information to the program |
| 436 | */ |
| 437 | static int create_elf_fdpic_tables(struct linux_binprm *bprm, |
| 438 | struct mm_struct *mm, |
| 439 | struct elf_fdpic_params *exec_params, |
| 440 | struct elf_fdpic_params *interp_params) |
| 441 | { |
| 442 | unsigned long sp, csp, nitems; |
| 443 | elf_caddr_t *argv, *envp; |
| 444 | size_t platform_len = 0, len; |
| 445 | char *k_platform, *u_platform, *p; |
| 446 | long hwcap; |
| 447 | int loop; |
| 448 | |
| 449 | /* we're going to shovel a whole load of stuff onto the stack */ |
| 450 | #ifdef CONFIG_MMU |
| 451 | sp = bprm->p; |
| 452 | #else |
| 453 | sp = mm->start_stack; |
| 454 | |
| 455 | /* stack the program arguments and environment */ |
| 456 | if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0) |
| 457 | return -EFAULT; |
| 458 | #endif |
| 459 | |
| 460 | /* get hold of platform and hardware capabilities masks for the machine |
| 461 | * we are running on. In some cases (Sparc), this info is impossible |
| 462 | * to get, in others (i386) it is merely difficult. |
| 463 | */ |
| 464 | hwcap = ELF_HWCAP; |
| 465 | k_platform = ELF_PLATFORM; |
| 466 | |
| 467 | if (k_platform) { |
| 468 | platform_len = strlen(k_platform) + 1; |
| 469 | sp -= platform_len; |
| 470 | if (__copy_to_user(u_platform, k_platform, platform_len) != 0) |
| 471 | return -EFAULT; |
| 472 | } |
| 473 | |
| 474 | u_platform = (char *) sp; |
| 475 | |
| 476 | #if defined(__i386__) && defined(CONFIG_SMP) |
| 477 | /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions |
| 478 | * by the processes running on the same package. One thing we can do |
| 479 | * is to shuffle the initial stack for them. |
| 480 | * |
| 481 | * the conditionals here are unneeded, but kept in to make the |
| 482 | * code behaviour the same as pre change unless we have hyperthreaded |
| 483 | * processors. This keeps Mr Marcelo Person happier but should be |
| 484 | * removed for 2.5 |
| 485 | */ |
| 486 | if (smp_num_siblings > 1) |
| 487 | sp = sp - ((current->pid % 64) << 7); |
| 488 | #endif |
| 489 | |
| 490 | sp &= ~7UL; |
| 491 | |
| 492 | /* stack the load map(s) */ |
| 493 | len = sizeof(struct elf32_fdpic_loadmap); |
| 494 | len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs; |
| 495 | sp = (sp - len) & ~7UL; |
| 496 | exec_params->map_addr = sp; |
| 497 | |
| 498 | if (copy_to_user((void *) sp, exec_params->loadmap, len) != 0) |
| 499 | return -EFAULT; |
| 500 | |
| 501 | current->mm->context.exec_fdpic_loadmap = (unsigned long) sp; |
| 502 | |
| 503 | if (interp_params->loadmap) { |
| 504 | len = sizeof(struct elf32_fdpic_loadmap); |
| 505 | len += sizeof(struct elf32_fdpic_loadseg) * interp_params->loadmap->nsegs; |
| 506 | sp = (sp - len) & ~7UL; |
| 507 | interp_params->map_addr = sp; |
| 508 | |
| 509 | if (copy_to_user((void *) sp, interp_params->loadmap, len) != 0) |
| 510 | return -EFAULT; |
| 511 | |
| 512 | current->mm->context.interp_fdpic_loadmap = (unsigned long) sp; |
| 513 | } |
| 514 | |
| 515 | /* force 16 byte _final_ alignment here for generality */ |
| 516 | #define DLINFO_ITEMS 13 |
| 517 | |
| 518 | nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0); |
| 519 | #ifdef DLINFO_ARCH_ITEMS |
| 520 | nitems += DLINFO_ARCH_ITEMS; |
| 521 | #endif |
| 522 | |
| 523 | csp = sp; |
| 524 | sp -= nitems * 2 * sizeof(unsigned long); |
| 525 | sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */ |
| 526 | sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */ |
| 527 | sp -= 1 * sizeof(unsigned long); /* argc */ |
| 528 | |
| 529 | csp -= sp & 15UL; |
| 530 | sp -= sp & 15UL; |
| 531 | |
| 532 | /* put the ELF interpreter info on the stack */ |
| 533 | #define NEW_AUX_ENT(nr, id, val) \ |
| 534 | do { \ |
| 535 | struct { unsigned long _id, _val; } *ent = (void *) csp; \ |
| 536 | __put_user((id), &ent[nr]._id); \ |
| 537 | __put_user((val), &ent[nr]._val); \ |
| 538 | } while (0) |
| 539 | |
| 540 | csp -= 2 * sizeof(unsigned long); |
| 541 | NEW_AUX_ENT(0, AT_NULL, 0); |
| 542 | if (k_platform) { |
| 543 | csp -= 2 * sizeof(unsigned long); |
| 544 | NEW_AUX_ENT(0, AT_PLATFORM, (elf_addr_t)(unsigned long) u_platform); |
| 545 | } |
| 546 | |
| 547 | csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long); |
| 548 | NEW_AUX_ENT( 0, AT_HWCAP, hwcap); |
| 549 | NEW_AUX_ENT( 1, AT_PAGESZ, PAGE_SIZE); |
| 550 | NEW_AUX_ENT( 2, AT_CLKTCK, CLOCKS_PER_SEC); |
| 551 | NEW_AUX_ENT( 3, AT_PHDR, exec_params->ph_addr); |
| 552 | NEW_AUX_ENT( 4, AT_PHENT, sizeof(struct elf_phdr)); |
| 553 | NEW_AUX_ENT( 5, AT_PHNUM, exec_params->hdr.e_phnum); |
| 554 | NEW_AUX_ENT( 6, AT_BASE, interp_params->elfhdr_addr); |
| 555 | NEW_AUX_ENT( 7, AT_FLAGS, 0); |
| 556 | NEW_AUX_ENT( 8, AT_ENTRY, exec_params->entry_addr); |
| 557 | NEW_AUX_ENT( 9, AT_UID, (elf_addr_t) current->uid); |
| 558 | NEW_AUX_ENT(10, AT_EUID, (elf_addr_t) current->euid); |
| 559 | NEW_AUX_ENT(11, AT_GID, (elf_addr_t) current->gid); |
| 560 | NEW_AUX_ENT(12, AT_EGID, (elf_addr_t) current->egid); |
| 561 | |
| 562 | #ifdef ARCH_DLINFO |
| 563 | /* ARCH_DLINFO must come last so platform specific code can enforce |
| 564 | * special alignment requirements on the AUXV if necessary (eg. PPC). |
| 565 | */ |
| 566 | ARCH_DLINFO; |
| 567 | #endif |
| 568 | #undef NEW_AUX_ENT |
| 569 | |
| 570 | /* allocate room for argv[] and envv[] */ |
| 571 | csp -= (bprm->envc + 1) * sizeof(elf_caddr_t); |
| 572 | envp = (elf_caddr_t *) csp; |
| 573 | csp -= (bprm->argc + 1) * sizeof(elf_caddr_t); |
| 574 | argv = (elf_caddr_t *) csp; |
| 575 | |
| 576 | /* stack argc */ |
| 577 | csp -= sizeof(unsigned long); |
| 578 | __put_user(bprm->argc, (unsigned long *) csp); |
| 579 | |
| 580 | if (csp != sp) |
| 581 | BUG(); |
| 582 | |
| 583 | /* fill in the argv[] array */ |
| 584 | #ifdef CONFIG_MMU |
| 585 | current->mm->arg_start = bprm->p; |
| 586 | #else |
| 587 | current->mm->arg_start = current->mm->start_stack - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p); |
| 588 | #endif |
| 589 | |
| 590 | p = (char *) current->mm->arg_start; |
| 591 | for (loop = bprm->argc; loop > 0; loop--) { |
| 592 | __put_user((elf_caddr_t) p, argv++); |
| 593 | len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); |
| 594 | if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) |
| 595 | return -EINVAL; |
| 596 | p += len; |
| 597 | } |
| 598 | __put_user(NULL, argv); |
| 599 | current->mm->arg_end = (unsigned long) p; |
| 600 | |
| 601 | /* fill in the envv[] array */ |
| 602 | current->mm->env_start = (unsigned long) p; |
| 603 | for (loop = bprm->envc; loop > 0; loop--) { |
| 604 | __put_user((elf_caddr_t)(unsigned long) p, envp++); |
| 605 | len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES); |
| 606 | if (!len || len > PAGE_SIZE * MAX_ARG_PAGES) |
| 607 | return -EINVAL; |
| 608 | p += len; |
| 609 | } |
| 610 | __put_user(NULL, envp); |
| 611 | current->mm->env_end = (unsigned long) p; |
| 612 | |
| 613 | mm->start_stack = (unsigned long) sp; |
| 614 | return 0; |
| 615 | } /* end create_elf_fdpic_tables() */ |
| 616 | |
| 617 | /*****************************************************************************/ |
| 618 | /* |
| 619 | * transfer the program arguments and environment from the holding pages onto |
| 620 | * the stack |
| 621 | */ |
| 622 | #ifndef CONFIG_MMU |
| 623 | static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp) |
| 624 | { |
| 625 | unsigned long index, stop, sp; |
| 626 | char *src; |
| 627 | int ret = 0; |
| 628 | |
| 629 | stop = bprm->p >> PAGE_SHIFT; |
| 630 | sp = *_sp; |
| 631 | |
| 632 | for (index = MAX_ARG_PAGES - 1; index >= stop; index--) { |
| 633 | src = kmap(bprm->page[index]); |
| 634 | sp -= PAGE_SIZE; |
| 635 | if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0) |
| 636 | ret = -EFAULT; |
| 637 | kunmap(bprm->page[index]); |
| 638 | if (ret < 0) |
| 639 | goto out; |
| 640 | } |
| 641 | |
| 642 | *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15; |
| 643 | |
| 644 | out: |
| 645 | return ret; |
| 646 | } /* end elf_fdpic_transfer_args_to_stack() */ |
| 647 | #endif |
| 648 | |
| 649 | /*****************************************************************************/ |
| 650 | /* |
| 651 | * load the appropriate binary image (executable or interpreter) into memory |
| 652 | * - we assume no MMU is available |
| 653 | * - if no other PIC bits are set in params->hdr->e_flags |
| 654 | * - we assume that the LOADable segments in the binary are independently relocatable |
| 655 | * - we assume R/O executable segments are shareable |
| 656 | * - else |
| 657 | * - we assume the loadable parts of the image to require fixed displacement |
| 658 | * - the image is not shareable |
| 659 | */ |
| 660 | static int elf_fdpic_map_file(struct elf_fdpic_params *params, |
| 661 | struct file *file, |
| 662 | struct mm_struct *mm, |
| 663 | const char *what) |
| 664 | { |
| 665 | struct elf32_fdpic_loadmap *loadmap; |
| 666 | #ifdef CONFIG_MMU |
| 667 | struct elf32_fdpic_loadseg *mseg; |
| 668 | #endif |
| 669 | struct elf32_fdpic_loadseg *seg; |
| 670 | struct elf32_phdr *phdr; |
| 671 | unsigned long load_addr, stop; |
| 672 | unsigned nloads, tmp; |
| 673 | size_t size; |
| 674 | int loop, ret; |
| 675 | |
| 676 | /* allocate a load map table */ |
| 677 | nloads = 0; |
| 678 | for (loop = 0; loop < params->hdr.e_phnum; loop++) |
| 679 | if (params->phdrs[loop].p_type == PT_LOAD) |
| 680 | nloads++; |
| 681 | |
| 682 | if (nloads == 0) |
| 683 | return -ELIBBAD; |
| 684 | |
| 685 | size = sizeof(*loadmap) + nloads * sizeof(*seg); |
| 686 | loadmap = kmalloc(size, GFP_KERNEL); |
| 687 | if (!loadmap) |
| 688 | return -ENOMEM; |
| 689 | |
| 690 | params->loadmap = loadmap; |
| 691 | memset(loadmap, 0, size); |
| 692 | |
| 693 | loadmap->version = ELF32_FDPIC_LOADMAP_VERSION; |
| 694 | loadmap->nsegs = nloads; |
| 695 | |
| 696 | load_addr = params->load_addr; |
| 697 | seg = loadmap->segs; |
| 698 | |
| 699 | /* map the requested LOADs into the memory space */ |
| 700 | switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { |
| 701 | case ELF_FDPIC_FLAG_CONSTDISP: |
| 702 | case ELF_FDPIC_FLAG_CONTIGUOUS: |
| 703 | #ifndef CONFIG_MMU |
| 704 | ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm); |
| 705 | if (ret < 0) |
| 706 | return ret; |
| 707 | break; |
| 708 | #endif |
| 709 | default: |
| 710 | ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm); |
| 711 | if (ret < 0) |
| 712 | return ret; |
| 713 | break; |
| 714 | } |
| 715 | |
| 716 | /* map the entry point */ |
| 717 | if (params->hdr.e_entry) { |
| 718 | seg = loadmap->segs; |
| 719 | for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { |
| 720 | if (params->hdr.e_entry >= seg->p_vaddr && |
| 721 | params->hdr.e_entry < seg->p_vaddr + seg->p_memsz |
| 722 | ) { |
| 723 | params->entry_addr = |
| 724 | (params->hdr.e_entry - seg->p_vaddr) + seg->addr; |
| 725 | break; |
| 726 | } |
| 727 | } |
| 728 | } |
| 729 | |
| 730 | /* determine where the program header table has wound up if mapped */ |
| 731 | stop = params->hdr.e_phoff + params->hdr.e_phnum * sizeof (struct elf_phdr); |
| 732 | phdr = params->phdrs; |
| 733 | |
| 734 | for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { |
| 735 | if (phdr->p_type != PT_LOAD) |
| 736 | continue; |
| 737 | |
| 738 | if (phdr->p_offset > params->hdr.e_phoff || |
| 739 | phdr->p_offset + phdr->p_filesz < stop) |
| 740 | continue; |
| 741 | |
| 742 | seg = loadmap->segs; |
| 743 | for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { |
| 744 | if (phdr->p_vaddr >= seg->p_vaddr && |
| 745 | phdr->p_vaddr + phdr->p_filesz <= seg->p_vaddr + seg->p_memsz |
| 746 | ) { |
| 747 | params->ph_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr + |
| 748 | params->hdr.e_phoff - phdr->p_offset; |
| 749 | break; |
| 750 | } |
| 751 | } |
| 752 | break; |
| 753 | } |
| 754 | |
| 755 | /* determine where the dynamic section has wound up if there is one */ |
| 756 | phdr = params->phdrs; |
| 757 | for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { |
| 758 | if (phdr->p_type != PT_DYNAMIC) |
| 759 | continue; |
| 760 | |
| 761 | seg = loadmap->segs; |
| 762 | for (loop = loadmap->nsegs; loop > 0; loop--, seg++) { |
| 763 | if (phdr->p_vaddr >= seg->p_vaddr && |
| 764 | phdr->p_vaddr + phdr->p_memsz <= seg->p_vaddr + seg->p_memsz |
| 765 | ) { |
| 766 | params->dynamic_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr; |
| 767 | |
| 768 | /* check the dynamic section contains at least one item, and that |
| 769 | * the last item is a NULL entry */ |
| 770 | if (phdr->p_memsz == 0 || |
| 771 | phdr->p_memsz % sizeof(Elf32_Dyn) != 0) |
| 772 | goto dynamic_error; |
| 773 | |
| 774 | tmp = phdr->p_memsz / sizeof(Elf32_Dyn); |
| 775 | if (((Elf32_Dyn *) params->dynamic_addr)[tmp - 1].d_tag != 0) |
| 776 | goto dynamic_error; |
| 777 | break; |
| 778 | } |
| 779 | } |
| 780 | break; |
| 781 | } |
| 782 | |
| 783 | /* now elide adjacent segments in the load map on MMU linux |
| 784 | * - on uClinux the holes between may actually be filled with system stuff or stuff from |
| 785 | * other processes |
| 786 | */ |
| 787 | #ifdef CONFIG_MMU |
| 788 | nloads = loadmap->nsegs; |
| 789 | mseg = loadmap->segs; |
| 790 | seg = mseg + 1; |
| 791 | for (loop = 1; loop < nloads; loop++) { |
| 792 | /* see if we have a candidate for merging */ |
| 793 | if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) { |
| 794 | load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz); |
| 795 | if (load_addr == (seg->addr & PAGE_MASK)) { |
| 796 | mseg->p_memsz += load_addr - (mseg->addr + mseg->p_memsz); |
| 797 | mseg->p_memsz += seg->addr & ~PAGE_MASK; |
| 798 | mseg->p_memsz += seg->p_memsz; |
| 799 | loadmap->nsegs--; |
| 800 | continue; |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | mseg++; |
| 805 | if (mseg != seg) |
| 806 | *mseg = *seg; |
| 807 | } |
| 808 | #endif |
| 809 | |
| 810 | kdebug("Mapped Object [%s]:", what); |
| 811 | kdebug("- elfhdr : %lx", params->elfhdr_addr); |
| 812 | kdebug("- entry : %lx", params->entry_addr); |
| 813 | kdebug("- PHDR[] : %lx", params->ph_addr); |
| 814 | kdebug("- DYNAMIC[]: %lx", params->dynamic_addr); |
| 815 | seg = loadmap->segs; |
| 816 | for (loop = 0; loop < loadmap->nsegs; loop++, seg++) |
| 817 | kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]", |
| 818 | loop, |
| 819 | seg->addr, seg->addr + seg->p_memsz - 1, |
| 820 | seg->p_vaddr, seg->p_memsz); |
| 821 | |
| 822 | return 0; |
| 823 | |
| 824 | dynamic_error: |
| 825 | printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n", |
| 826 | what, file->f_dentry->d_inode->i_ino); |
| 827 | return -ELIBBAD; |
| 828 | } /* end elf_fdpic_map_file() */ |
| 829 | |
| 830 | /*****************************************************************************/ |
| 831 | /* |
| 832 | * map a file with constant displacement under uClinux |
| 833 | */ |
| 834 | #ifndef CONFIG_MMU |
| 835 | static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params, |
| 836 | struct file *file, |
| 837 | struct mm_struct *mm) |
| 838 | { |
| 839 | struct elf32_fdpic_loadseg *seg; |
| 840 | struct elf32_phdr *phdr; |
| 841 | unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags; |
| 842 | loff_t fpos; |
| 843 | int loop, ret; |
| 844 | |
| 845 | load_addr = params->load_addr; |
| 846 | seg = params->loadmap->segs; |
| 847 | |
| 848 | /* determine the bounds of the contiguous overall allocation we must make */ |
| 849 | phdr = params->phdrs; |
| 850 | for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { |
| 851 | if (params->phdrs[loop].p_type != PT_LOAD) |
| 852 | continue; |
| 853 | |
| 854 | if (base > phdr->p_vaddr) |
| 855 | base = phdr->p_vaddr; |
| 856 | if (top < phdr->p_vaddr + phdr->p_memsz) |
| 857 | top = phdr->p_vaddr + phdr->p_memsz; |
| 858 | } |
| 859 | |
| 860 | /* allocate one big anon block for everything */ |
| 861 | mflags = MAP_PRIVATE; |
| 862 | if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) |
| 863 | mflags |= MAP_EXECUTABLE; |
| 864 | |
| 865 | down_write(&mm->mmap_sem); |
| 866 | maddr = do_mmap(NULL, load_addr, top - base, |
| 867 | PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0); |
| 868 | up_write(&mm->mmap_sem); |
| 869 | if (IS_ERR((void *) maddr)) |
| 870 | return (int) maddr; |
| 871 | |
| 872 | if (load_addr != 0) |
| 873 | load_addr += PAGE_ALIGN(top - base); |
| 874 | |
| 875 | /* and then load the file segments into it */ |
| 876 | phdr = params->phdrs; |
| 877 | for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { |
| 878 | if (params->phdrs[loop].p_type != PT_LOAD) |
| 879 | continue; |
| 880 | |
| 881 | fpos = phdr->p_offset; |
| 882 | |
| 883 | seg->addr = maddr + (phdr->p_vaddr - base); |
| 884 | seg->p_vaddr = phdr->p_vaddr; |
| 885 | seg->p_memsz = phdr->p_memsz; |
| 886 | |
| 887 | ret = file->f_op->read(file, (void *) seg->addr, phdr->p_filesz, &fpos); |
| 888 | if (ret < 0) |
| 889 | return ret; |
| 890 | |
| 891 | /* map the ELF header address if in this segment */ |
| 892 | if (phdr->p_offset == 0) |
| 893 | params->elfhdr_addr = seg->addr; |
| 894 | |
| 895 | /* clear any space allocated but not loaded */ |
| 896 | if (phdr->p_filesz < phdr->p_memsz) |
| 897 | clear_user((void *) (seg->addr + phdr->p_filesz), |
| 898 | phdr->p_memsz - phdr->p_filesz); |
| 899 | |
| 900 | if (mm) { |
| 901 | if (phdr->p_flags & PF_X) { |
| 902 | mm->start_code = seg->addr; |
| 903 | mm->end_code = seg->addr + phdr->p_memsz; |
| 904 | } |
| 905 | else if (!mm->start_data) { |
| 906 | mm->start_data = seg->addr; |
| 907 | #ifndef CONFIG_MMU |
| 908 | mm->end_data = seg->addr + phdr->p_memsz; |
| 909 | #endif |
| 910 | } |
| 911 | |
| 912 | #ifdef CONFIG_MMU |
| 913 | if (seg->addr + phdr->p_memsz > mm->end_data) |
| 914 | mm->end_data = seg->addr + phdr->p_memsz; |
| 915 | #endif |
| 916 | } |
| 917 | |
| 918 | seg++; |
| 919 | } |
| 920 | |
| 921 | return 0; |
| 922 | } /* end elf_fdpic_map_file_constdisp_on_uclinux() */ |
| 923 | #endif |
| 924 | |
| 925 | /*****************************************************************************/ |
| 926 | /* |
| 927 | * map a binary by direct mmap() of the individual PT_LOAD segments |
| 928 | */ |
| 929 | static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, |
| 930 | struct file *file, |
| 931 | struct mm_struct *mm) |
| 932 | { |
| 933 | struct elf32_fdpic_loadseg *seg; |
| 934 | struct elf32_phdr *phdr; |
| 935 | unsigned long load_addr, delta_vaddr; |
| 936 | int loop, dvset; |
| 937 | |
| 938 | load_addr = params->load_addr; |
| 939 | delta_vaddr = 0; |
| 940 | dvset = 0; |
| 941 | |
| 942 | seg = params->loadmap->segs; |
| 943 | |
| 944 | /* deal with each load segment separately */ |
| 945 | phdr = params->phdrs; |
| 946 | for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) { |
| 947 | unsigned long maddr, disp, excess, excess1; |
| 948 | int prot = 0, flags; |
| 949 | |
| 950 | if (phdr->p_type != PT_LOAD) |
| 951 | continue; |
| 952 | |
| 953 | kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx", |
| 954 | (unsigned long) phdr->p_vaddr, |
| 955 | (unsigned long) phdr->p_offset, |
| 956 | (unsigned long) phdr->p_filesz, |
| 957 | (unsigned long) phdr->p_memsz); |
| 958 | |
| 959 | /* determine the mapping parameters */ |
| 960 | if (phdr->p_flags & PF_R) prot |= PROT_READ; |
| 961 | if (phdr->p_flags & PF_W) prot |= PROT_WRITE; |
| 962 | if (phdr->p_flags & PF_X) prot |= PROT_EXEC; |
| 963 | |
| 964 | flags = MAP_PRIVATE | MAP_DENYWRITE; |
| 965 | if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE) |
| 966 | flags |= MAP_EXECUTABLE; |
| 967 | |
| 968 | maddr = 0; |
| 969 | |
| 970 | switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) { |
| 971 | case ELF_FDPIC_FLAG_INDEPENDENT: |
| 972 | /* PT_LOADs are independently locatable */ |
| 973 | break; |
| 974 | |
| 975 | case ELF_FDPIC_FLAG_HONOURVADDR: |
| 976 | /* the specified virtual address must be honoured */ |
| 977 | maddr = phdr->p_vaddr; |
| 978 | flags |= MAP_FIXED; |
| 979 | break; |
| 980 | |
| 981 | case ELF_FDPIC_FLAG_CONSTDISP: |
| 982 | /* constant displacement |
| 983 | * - can be mapped anywhere, but must be mapped as a unit |
| 984 | */ |
| 985 | if (!dvset) { |
| 986 | maddr = load_addr; |
| 987 | delta_vaddr = phdr->p_vaddr; |
| 988 | dvset = 1; |
| 989 | } |
| 990 | else { |
| 991 | maddr = load_addr + phdr->p_vaddr - delta_vaddr; |
| 992 | flags |= MAP_FIXED; |
| 993 | } |
| 994 | break; |
| 995 | |
| 996 | case ELF_FDPIC_FLAG_CONTIGUOUS: |
| 997 | /* contiguity handled later */ |
| 998 | break; |
| 999 | |
| 1000 | default: |
| 1001 | BUG(); |
| 1002 | } |
| 1003 | |
| 1004 | maddr &= PAGE_MASK; |
| 1005 | |
| 1006 | /* create the mapping */ |
| 1007 | disp = phdr->p_vaddr & ~PAGE_MASK; |
| 1008 | down_write(&mm->mmap_sem); |
| 1009 | maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags, |
| 1010 | phdr->p_offset - disp); |
| 1011 | up_write(&mm->mmap_sem); |
| 1012 | |
| 1013 | kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx", |
| 1014 | loop, phdr->p_memsz + disp, prot, flags, phdr->p_offset - disp, |
| 1015 | maddr); |
| 1016 | |
| 1017 | if (IS_ERR((void *) maddr)) |
| 1018 | return (int) maddr; |
| 1019 | |
| 1020 | if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == ELF_FDPIC_FLAG_CONTIGUOUS) |
| 1021 | load_addr += PAGE_ALIGN(phdr->p_memsz + disp); |
| 1022 | |
| 1023 | seg->addr = maddr + disp; |
| 1024 | seg->p_vaddr = phdr->p_vaddr; |
| 1025 | seg->p_memsz = phdr->p_memsz; |
| 1026 | |
| 1027 | /* map the ELF header address if in this segment */ |
| 1028 | if (phdr->p_offset == 0) |
| 1029 | params->elfhdr_addr = seg->addr; |
| 1030 | |
| 1031 | /* clear the bit between beginning of mapping and beginning of PT_LOAD */ |
| 1032 | if (prot & PROT_WRITE && disp > 0) { |
| 1033 | kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp); |
| 1034 | clear_user((void *) maddr, disp); |
| 1035 | maddr += disp; |
| 1036 | } |
| 1037 | |
| 1038 | /* clear any space allocated but not loaded |
| 1039 | * - on uClinux we can just clear the lot |
| 1040 | * - on MMU linux we'll get a SIGBUS beyond the last page |
| 1041 | * extant in the file |
| 1042 | */ |
| 1043 | excess = phdr->p_memsz - phdr->p_filesz; |
| 1044 | excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK); |
| 1045 | |
| 1046 | #ifdef CONFIG_MMU |
| 1047 | |
| 1048 | if (excess > excess1) { |
| 1049 | unsigned long xaddr = maddr + phdr->p_filesz + excess1; |
| 1050 | unsigned long xmaddr; |
| 1051 | |
| 1052 | flags |= MAP_FIXED | MAP_ANONYMOUS; |
| 1053 | down_write(&mm->mmap_sem); |
| 1054 | xmaddr = do_mmap(NULL, xaddr, excess - excess1, prot, flags, 0); |
| 1055 | up_write(&mm->mmap_sem); |
| 1056 | |
| 1057 | kdebug("mmap[%d] <anon>" |
| 1058 | " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx", |
| 1059 | loop, xaddr, excess - excess1, prot, flags, xmaddr); |
| 1060 | |
| 1061 | if (xmaddr != xaddr) |
| 1062 | return -ENOMEM; |
| 1063 | } |
| 1064 | |
| 1065 | if (prot & PROT_WRITE && excess1 > 0) { |
| 1066 | kdebug("clear[%d] ad=%lx sz=%lx", |
| 1067 | loop, maddr + phdr->p_filesz, excess1); |
| 1068 | clear_user((void *) maddr + phdr->p_filesz, excess1); |
| 1069 | } |
| 1070 | |
| 1071 | #else |
| 1072 | if (excess > 0) { |
| 1073 | kdebug("clear[%d] ad=%lx sz=%lx", |
| 1074 | loop, maddr + phdr->p_filesz, excess); |
| 1075 | clear_user((void *) maddr + phdr->p_filesz, excess); |
| 1076 | } |
| 1077 | #endif |
| 1078 | |
| 1079 | if (mm) { |
| 1080 | if (phdr->p_flags & PF_X) { |
| 1081 | mm->start_code = maddr; |
| 1082 | mm->end_code = maddr + phdr->p_memsz; |
| 1083 | } |
| 1084 | else if (!mm->start_data) { |
| 1085 | mm->start_data = maddr; |
| 1086 | mm->end_data = maddr + phdr->p_memsz; |
| 1087 | } |
| 1088 | } |
| 1089 | |
| 1090 | seg++; |
| 1091 | } |
| 1092 | |
| 1093 | return 0; |
| 1094 | } /* end elf_fdpic_map_file_by_direct_mmap() */ |