/arch/x86_64/ia32/ia32_aout.c
C | 529 lines | 407 code | 68 blank | 54 comment | 71 complexity | 1bfa252d5fbce4f50d15b5f8761352fe MD5 | raw file
1/* 2 * a.out loader for x86-64 3 * 4 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 5 * Hacked together by Andi Kleen 6 */ 7 8#include <linux/module.h> 9 10#include <linux/time.h> 11#include <linux/kernel.h> 12#include <linux/mm.h> 13#include <linux/mman.h> 14#include <linux/a.out.h> 15#include <linux/errno.h> 16#include <linux/signal.h> 17#include <linux/string.h> 18#include <linux/fs.h> 19#include <linux/file.h> 20#include <linux/stat.h> 21#include <linux/fcntl.h> 22#include <linux/ptrace.h> 23#include <linux/user.h> 24#include <linux/slab.h> 25#include <linux/binfmts.h> 26#include <linux/personality.h> 27#include <linux/init.h> 28 29#include <asm/system.h> 30#include <asm/uaccess.h> 31#include <asm/pgalloc.h> 32#include <asm/cacheflush.h> 33#include <asm/user32.h> 34#include <asm/ia32.h> 35 36#undef WARN_OLD 37#undef CORE_DUMP /* probably broken */ 38 39extern int ia32_setup_arg_pages(struct linux_binprm *bprm, 40 unsigned long stack_top, int exec_stack); 41 42static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs); 43static int load_aout_library(struct file*); 44 45#if CORE_DUMP 46static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file); 47 48/* 49 * fill in the user structure for a core dump.. 50 */ 51static void dump_thread32(struct pt_regs * regs, struct user32 * dump) 52{ 53 u32 fs,gs; 54 55/* changed the size calculations - should hopefully work better. lbt */ 56 dump->magic = CMAGIC; 57 dump->start_code = 0; 58 dump->start_stack = regs->rsp & ~(PAGE_SIZE - 1); 59 dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT; 60 dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT; 61 dump->u_dsize -= dump->u_tsize; 62 dump->u_ssize = 0; 63 dump->u_debugreg[0] = current->thread.debugreg0; 64 dump->u_debugreg[1] = current->thread.debugreg1; 65 dump->u_debugreg[2] = current->thread.debugreg2; 66 dump->u_debugreg[3] = current->thread.debugreg3; 67 dump->u_debugreg[4] = 0; 68 dump->u_debugreg[5] = 0; 69 dump->u_debugreg[6] = current->thread.debugreg6; 70 dump->u_debugreg[7] = current->thread.debugreg7; 71 72 if (dump->start_stack < 0xc0000000) 73 dump->u_ssize = ((unsigned long) (0xc0000000 - dump->start_stack)) >> PAGE_SHIFT; 74 75 dump->regs.ebx = regs->rbx; 76 dump->regs.ecx = regs->rcx; 77 dump->regs.edx = regs->rdx; 78 dump->regs.esi = regs->rsi; 79 dump->regs.edi = regs->rdi; 80 dump->regs.ebp = regs->rbp; 81 dump->regs.eax = regs->rax; 82 dump->regs.ds = current->thread.ds; 83 dump->regs.es = current->thread.es; 84 asm("movl %%fs,%0" : "=r" (fs)); dump->regs.fs = fs; 85 asm("movl %%gs,%0" : "=r" (gs)); dump->regs.gs = gs; 86 dump->regs.orig_eax = regs->orig_rax; 87 dump->regs.eip = regs->rip; 88 dump->regs.cs = regs->cs; 89 dump->regs.eflags = regs->eflags; 90 dump->regs.esp = regs->rsp; 91 dump->regs.ss = regs->ss; 92 93#if 1 /* FIXME */ 94 dump->u_fpvalid = 0; 95#else 96 dump->u_fpvalid = dump_fpu (regs, &dump->i387); 97#endif 98} 99 100#endif 101 102static struct linux_binfmt aout_format = { 103 .module = THIS_MODULE, 104 .load_binary = load_aout_binary, 105 .load_shlib = load_aout_library, 106#if CORE_DUMP 107 .core_dump = aout_core_dump, 108#endif 109 .min_coredump = PAGE_SIZE 110}; 111 112static void set_brk(unsigned long start, unsigned long end) 113{ 114 start = PAGE_ALIGN(start); 115 end = PAGE_ALIGN(end); 116 if (end <= start) 117 return; 118 down_write(¤t->mm->mmap_sem); 119 do_brk(start, end - start); 120 up_write(¤t->mm->mmap_sem); 121} 122 123#if CORE_DUMP 124/* 125 * These are the only things you should do on a core-file: use only these 126 * macros to write out all the necessary info. 127 */ 128 129static int dump_write(struct file *file, const void *addr, int nr) 130{ 131 return file->f_op->write(file, addr, nr, &file->f_pos) == nr; 132} 133 134#define DUMP_WRITE(addr, nr) \ 135 if (!dump_write(file, (void *)(addr), (nr))) \ 136 goto end_coredump; 137 138#define DUMP_SEEK(offset) \ 139if (file->f_op->llseek) { \ 140 if (file->f_op->llseek(file,(offset),0) != (offset)) \ 141 goto end_coredump; \ 142} else file->f_pos = (offset) 143 144/* 145 * Routine writes a core dump image in the current directory. 146 * Currently only a stub-function. 147 * 148 * Note that setuid/setgid files won't make a core-dump if the uid/gid 149 * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable" 150 * field, which also makes sure the core-dumps won't be recursive if the 151 * dumping of the process results in another error.. 152 */ 153 154static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file) 155{ 156 mm_segment_t fs; 157 int has_dumped = 0; 158 unsigned long dump_start, dump_size; 159 struct user32 dump; 160# define START_DATA(u) (u.u_tsize << PAGE_SHIFT) 161# define START_STACK(u) (u.start_stack) 162 163 fs = get_fs(); 164 set_fs(KERNEL_DS); 165 has_dumped = 1; 166 current->flags |= PF_DUMPCORE; 167 strncpy(dump.u_comm, current->comm, sizeof(current->comm)); 168 dump.u_ar0 = (u32)(((unsigned long)(&dump.regs)) - ((unsigned long)(&dump))); 169 dump.signal = signr; 170 dump_thread32(regs, &dump); 171 172/* If the size of the dump file exceeds the rlimit, then see what would happen 173 if we wrote the stack, but not the data area. */ 174 if ((dump.u_dsize+dump.u_ssize+1) * PAGE_SIZE > 175 current->signal->rlim[RLIMIT_CORE].rlim_cur) 176 dump.u_dsize = 0; 177 178/* Make sure we have enough room to write the stack and data areas. */ 179 if ((dump.u_ssize+1) * PAGE_SIZE > 180 current->signal->rlim[RLIMIT_CORE].rlim_cur) 181 dump.u_ssize = 0; 182 183/* make sure we actually have a data and stack area to dump */ 184 set_fs(USER_DS); 185 if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_DATA(dump), dump.u_dsize << PAGE_SHIFT)) 186 dump.u_dsize = 0; 187 if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_STACK(dump), dump.u_ssize << PAGE_SHIFT)) 188 dump.u_ssize = 0; 189 190 set_fs(KERNEL_DS); 191/* struct user */ 192 DUMP_WRITE(&dump,sizeof(dump)); 193/* Now dump all of the user data. Include malloced stuff as well */ 194 DUMP_SEEK(PAGE_SIZE); 195/* now we start writing out the user space info */ 196 set_fs(USER_DS); 197/* Dump the data area */ 198 if (dump.u_dsize != 0) { 199 dump_start = START_DATA(dump); 200 dump_size = dump.u_dsize << PAGE_SHIFT; 201 DUMP_WRITE(dump_start,dump_size); 202 } 203/* Now prepare to dump the stack area */ 204 if (dump.u_ssize != 0) { 205 dump_start = START_STACK(dump); 206 dump_size = dump.u_ssize << PAGE_SHIFT; 207 DUMP_WRITE(dump_start,dump_size); 208 } 209/* Finally dump the task struct. Not be used by gdb, but could be useful */ 210 set_fs(KERNEL_DS); 211 DUMP_WRITE(current,sizeof(*current)); 212end_coredump: 213 set_fs(fs); 214 return has_dumped; 215} 216#endif 217 218/* 219 * create_aout_tables() parses the env- and arg-strings in new user 220 * memory and creates the pointer tables from them, and puts their 221 * addresses on the "stack", returning the new stack pointer value. 222 */ 223static u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm) 224{ 225 u32 __user *argv; 226 u32 __user *envp; 227 u32 __user *sp; 228 int argc = bprm->argc; 229 int envc = bprm->envc; 230 231 sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p); 232 sp -= envc+1; 233 envp = sp; 234 sp -= argc+1; 235 argv = sp; 236 put_user((unsigned long) envp,--sp); 237 put_user((unsigned long) argv,--sp); 238 put_user(argc,--sp); 239 current->mm->arg_start = (unsigned long) p; 240 while (argc-->0) { 241 char c; 242 put_user((u32)(unsigned long)p,argv++); 243 do { 244 get_user(c,p++); 245 } while (c); 246 } 247 put_user(NULL,argv); 248 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 249 while (envc-->0) { 250 char c; 251 put_user((u32)(unsigned long)p,envp++); 252 do { 253 get_user(c,p++); 254 } while (c); 255 } 256 put_user(NULL,envp); 257 current->mm->env_end = (unsigned long) p; 258 return sp; 259} 260 261/* 262 * These are the functions used to load a.out style executables and shared 263 * libraries. There is no binary dependent code anywhere else. 264 */ 265 266static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs) 267{ 268 struct exec ex; 269 unsigned long error; 270 unsigned long fd_offset; 271 unsigned long rlim; 272 int retval; 273 274 ex = *((struct exec *) bprm->buf); /* exec-header */ 275 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC && 276 N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) || 277 N_TRSIZE(ex) || N_DRSIZE(ex) || 278 i_size_read(bprm->file->f_dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { 279 return -ENOEXEC; 280 } 281 282 fd_offset = N_TXTOFF(ex); 283 284 /* Check initial limits. This avoids letting people circumvent 285 * size limits imposed on them by creating programs with large 286 * arrays in the data or bss. 287 */ 288 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 289 if (rlim >= RLIM_INFINITY) 290 rlim = ~0; 291 if (ex.a_data + ex.a_bss > rlim) 292 return -ENOMEM; 293 294 /* Flush all traces of the currently running executable */ 295 retval = flush_old_exec(bprm); 296 if (retval) 297 return retval; 298 299 regs->cs = __USER32_CS; 300 regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 = 301 regs->r13 = regs->r14 = regs->r15 = 0; 302 303 /* OK, This is the point of no return */ 304 set_personality(PER_LINUX); 305 set_thread_flag(TIF_IA32); 306 clear_thread_flag(TIF_ABI_PENDING); 307 308 current->mm->end_code = ex.a_text + 309 (current->mm->start_code = N_TXTADDR(ex)); 310 current->mm->end_data = ex.a_data + 311 (current->mm->start_data = N_DATADDR(ex)); 312 current->mm->brk = ex.a_bss + 313 (current->mm->start_brk = N_BSSADDR(ex)); 314 current->mm->free_area_cache = TASK_UNMAPPED_BASE; 315 316 set_mm_counter(current->mm, rss, 0); 317 current->mm->mmap = NULL; 318 compute_creds(bprm); 319 current->flags &= ~PF_FORKNOEXEC; 320 321 if (N_MAGIC(ex) == OMAGIC) { 322 unsigned long text_addr, map_size; 323 loff_t pos; 324 325 text_addr = N_TXTADDR(ex); 326 327 pos = 32; 328 map_size = ex.a_text+ex.a_data; 329 330 down_write(¤t->mm->mmap_sem); 331 error = do_brk(text_addr & PAGE_MASK, map_size); 332 up_write(¤t->mm->mmap_sem); 333 334 if (error != (text_addr & PAGE_MASK)) { 335 send_sig(SIGKILL, current, 0); 336 return error; 337 } 338 339 error = bprm->file->f_op->read(bprm->file, (char *)text_addr, 340 ex.a_text+ex.a_data, &pos); 341 if ((signed long)error < 0) { 342 send_sig(SIGKILL, current, 0); 343 return error; 344 } 345 346 flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data); 347 } else { 348#ifdef WARN_OLD 349 static unsigned long error_time, error_time2; 350 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) && 351 (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time2) > 5*HZ) 352 { 353 printk(KERN_NOTICE "executable not page aligned\n"); 354 error_time2 = jiffies; 355 } 356 357 if ((fd_offset & ~PAGE_MASK) != 0 && 358 (jiffies-error_time) > 5*HZ) 359 { 360 printk(KERN_WARNING 361 "fd_offset is not page aligned. Please convert program: %s\n", 362 bprm->file->f_dentry->d_name.name); 363 error_time = jiffies; 364 } 365#endif 366 367 if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) { 368 loff_t pos = fd_offset; 369 down_write(¤t->mm->mmap_sem); 370 do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data); 371 up_write(¤t->mm->mmap_sem); 372 bprm->file->f_op->read(bprm->file,(char *)N_TXTADDR(ex), 373 ex.a_text+ex.a_data, &pos); 374 flush_icache_range((unsigned long) N_TXTADDR(ex), 375 (unsigned long) N_TXTADDR(ex) + 376 ex.a_text+ex.a_data); 377 goto beyond_if; 378 } 379 380 down_write(¤t->mm->mmap_sem); 381 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text, 382 PROT_READ | PROT_EXEC, 383 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE | MAP_32BIT, 384 fd_offset); 385 up_write(¤t->mm->mmap_sem); 386 387 if (error != N_TXTADDR(ex)) { 388 send_sig(SIGKILL, current, 0); 389 return error; 390 } 391 392 down_write(¤t->mm->mmap_sem); 393 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data, 394 PROT_READ | PROT_WRITE | PROT_EXEC, 395 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE | MAP_32BIT, 396 fd_offset + ex.a_text); 397 up_write(¤t->mm->mmap_sem); 398 if (error != N_DATADDR(ex)) { 399 send_sig(SIGKILL, current, 0); 400 return error; 401 } 402 } 403beyond_if: 404 set_binfmt(&aout_format); 405 406 set_brk(current->mm->start_brk, current->mm->brk); 407 408 retval = ia32_setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT); 409 if (retval < 0) { 410 /* Someone check-me: is this error path enough? */ 411 send_sig(SIGKILL, current, 0); 412 return retval; 413 } 414 415 current->mm->start_stack = 416 (unsigned long)create_aout_tables((char __user *)bprm->p, bprm); 417 /* start thread */ 418 asm volatile("movl %0,%%fs" :: "r" (0)); \ 419 asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS)); 420 load_gs_index(0); 421 (regs)->rip = ex.a_entry; 422 (regs)->rsp = current->mm->start_stack; 423 (regs)->eflags = 0x200; 424 (regs)->cs = __USER32_CS; 425 (regs)->ss = __USER32_DS; 426 set_fs(USER_DS); 427 if (unlikely(current->ptrace & PT_PTRACED)) { 428 if (current->ptrace & PT_TRACE_EXEC) 429 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP); 430 else 431 send_sig(SIGTRAP, current, 0); 432 } 433 return 0; 434} 435 436static int load_aout_library(struct file *file) 437{ 438 struct inode * inode; 439 unsigned long bss, start_addr, len; 440 unsigned long error; 441 int retval; 442 struct exec ex; 443 444 inode = file->f_dentry->d_inode; 445 446 retval = -ENOEXEC; 447 error = kernel_read(file, 0, (char *) &ex, sizeof(ex)); 448 if (error != sizeof(ex)) 449 goto out; 450 451 /* We come in here for the regular a.out style of shared libraries */ 452 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) || 453 N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) || 454 i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) { 455 goto out; 456 } 457 458 if (N_FLAGS(ex)) 459 goto out; 460 461 /* For QMAGIC, the starting address is 0x20 into the page. We mask 462 this off to get the starting address for the page */ 463 464 start_addr = ex.a_entry & 0xfffff000; 465 466 if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) { 467 loff_t pos = N_TXTOFF(ex); 468 469#ifdef WARN_OLD 470 static unsigned long error_time; 471 if ((jiffies-error_time) > 5*HZ) 472 { 473 printk(KERN_WARNING 474 "N_TXTOFF is not page aligned. Please convert library: %s\n", 475 file->f_dentry->d_name.name); 476 error_time = jiffies; 477 } 478#endif 479 down_write(¤t->mm->mmap_sem); 480 do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss); 481 up_write(¤t->mm->mmap_sem); 482 483 file->f_op->read(file, (char *)start_addr, 484 ex.a_text + ex.a_data, &pos); 485 flush_icache_range((unsigned long) start_addr, 486 (unsigned long) start_addr + ex.a_text + ex.a_data); 487 488 retval = 0; 489 goto out; 490 } 491 /* Now use mmap to map the library into memory. */ 492 down_write(¤t->mm->mmap_sem); 493 error = do_mmap(file, start_addr, ex.a_text + ex.a_data, 494 PROT_READ | PROT_WRITE | PROT_EXEC, 495 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT, 496 N_TXTOFF(ex)); 497 up_write(¤t->mm->mmap_sem); 498 retval = error; 499 if (error != start_addr) 500 goto out; 501 502 len = PAGE_ALIGN(ex.a_text + ex.a_data); 503 bss = ex.a_text + ex.a_data + ex.a_bss; 504 if (bss > len) { 505 down_write(¤t->mm->mmap_sem); 506 error = do_brk(start_addr + len, bss - len); 507 up_write(¤t->mm->mmap_sem); 508 retval = error; 509 if (error != start_addr + len) 510 goto out; 511 } 512 retval = 0; 513out: 514 return retval; 515} 516 517static int __init init_aout_binfmt(void) 518{ 519 return register_binfmt(&aout_format); 520} 521 522static void __exit exit_aout_binfmt(void) 523{ 524 unregister_binfmt(&aout_format); 525} 526 527module_init(init_aout_binfmt); 528module_exit(exit_aout_binfmt); 529MODULE_LICENSE("GPL");