linux_exec_aout.c revision 1.20
1 /* $NetBSD: linux_exec_aout.c,v 1.20 1996/10/03 02:16:18 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Frank van der Linden 5 * Copyright (c) 1994 Christos Zoulas 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * based on exec_aout.c, sunos_exec.c and svr4_exec.c 31 */ 32 33 #define ELFSIZE 32 /* XXX should die */ 34 #ifndef EXEC_ELF32 /* XXX should die */ 35 #define EXEC_ELF32 /* XXX should die */ 36 #endif /* XXX should die */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/proc.h> 42 #include <sys/malloc.h> 43 #include <sys/namei.h> 44 #include <sys/vnode.h> 45 #include <sys/mount.h> 46 #include <sys/exec_elf.h> 47 48 #include <sys/mman.h> 49 #include <sys/syscallargs.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_param.h> 53 #include <vm/vm_map.h> 54 55 #include <machine/cpu.h> 56 #include <machine/reg.h> 57 #include <machine/exec.h> 58 #include <machine/linux_machdep.h> 59 60 #include <compat/linux/linux_types.h> 61 #include <compat/linux/linux_syscall.h> 62 #include <compat/linux/linux_signal.h> 63 #include <compat/linux/linux_syscallargs.h> 64 #include <compat/linux/linux_util.h> 65 #include <compat/linux/linux_exec.h> 66 67 static void *linux_aout_copyargs __P((struct exec_package *, 68 struct ps_strings *, void *, void *)); 69 static int linux_elf32_signature __P((struct proc *p, struct exec_package *, 70 Elf32_Ehdr *)); 71 72 #define LINUX_AOUT_AUX_ARGSIZ 2 73 #define LINUX_ELF_AUX_ARGSIZ (sizeof(AuxInfo) * 8 / sizeof(char *)) 74 75 76 const char linux_emul_path[] = "/emul/linux"; 77 extern int linux_error[]; 78 extern char linux_sigcode[], linux_esigcode[]; 79 extern struct sysent linux_sysent[]; 80 extern char *linux_syscallnames[]; 81 82 int exec_linux_aout_prep_zmagic __P((struct proc *, struct exec_package *)); 83 int exec_linux_aout_prep_nmagic __P((struct proc *, struct exec_package *)); 84 int exec_linux_aout_prep_omagic __P((struct proc *, struct exec_package *)); 85 int exec_linux_aout_prep_qmagic __P((struct proc *, struct exec_package *)); 86 87 struct emul emul_linux_aout = { 88 "linux", 89 linux_error, 90 linux_sendsig, 91 LINUX_SYS_syscall, 92 LINUX_SYS_MAXSYSCALL, 93 linux_sysent, 94 linux_syscallnames, 95 LINUX_AOUT_AUX_ARGSIZ, 96 linux_aout_copyargs, 97 setregs, 98 linux_sigcode, 99 linux_esigcode, 100 }; 101 102 struct emul emul_linux_elf = { 103 "linux", 104 linux_error, 105 linux_sendsig, 106 LINUX_SYS_syscall, 107 LINUX_SYS_MAXSYSCALL, 108 linux_sysent, 109 linux_syscallnames, 110 LINUX_ELF_AUX_ARGSIZ, 111 elf32_copyargs, 112 setregs, 113 linux_sigcode, 114 linux_esigcode, 115 }; 116 117 118 static void * 119 linux_aout_copyargs(pack, arginfo, stack, argp) 120 struct exec_package *pack; 121 struct ps_strings *arginfo; 122 void *stack; 123 void *argp; 124 { 125 char **cpp = stack; 126 char **stk = stack; 127 char *dp, *sp; 128 size_t len; 129 void *nullp = NULL; 130 int argc = arginfo->ps_nargvstr; 131 int envc = arginfo->ps_nenvstr; 132 133 if (copyout(&argc, cpp++, sizeof(argc))) 134 return NULL; 135 136 /* leave room for envp and argv */ 137 cpp += 2; 138 if (copyout(&cpp, &stk[1], sizeof (cpp))) 139 return NULL; 140 141 dp = (char *) (cpp + argc + envc + 2); 142 sp = argp; 143 144 /* XXX don't copy them out, remap them! */ 145 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 146 147 for (; --argc >= 0; sp += len, dp += len) 148 if (copyout(&dp, cpp++, sizeof(dp)) || 149 copyoutstr(sp, dp, ARG_MAX, &len)) 150 return NULL; 151 152 if (copyout(&nullp, cpp++, sizeof(nullp))) 153 return NULL; 154 155 if (copyout(&cpp, &stk[2], sizeof (cpp))) 156 return NULL; 157 158 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 159 160 for (; --envc >= 0; sp += len, dp += len) 161 if (copyout(&dp, cpp++, sizeof(dp)) || 162 copyoutstr(sp, dp, ARG_MAX, &len)) 163 return NULL; 164 165 if (copyout(&nullp, cpp++, sizeof(nullp))) 166 return NULL; 167 168 return cpp; 169 } 170 171 int 172 exec_linux_aout_makecmds(p, epp) 173 struct proc *p; 174 struct exec_package *epp; 175 { 176 struct exec *linux_ep = epp->ep_hdr; 177 int machtype, magic; 178 int error = ENOEXEC; 179 180 magic = LINUX_N_MAGIC(linux_ep); 181 machtype = LINUX_N_MACHTYPE(linux_ep); 182 183 184 if (machtype != LINUX_MID_MACHINE) 185 return (ENOEXEC); 186 187 switch (magic) { 188 case QMAGIC: 189 error = exec_linux_aout_prep_qmagic(p, epp); 190 break; 191 case ZMAGIC: 192 error = exec_linux_aout_prep_zmagic(p, epp); 193 break; 194 case NMAGIC: 195 error = exec_linux_aout_prep_nmagic(p, epp); 196 break; 197 case OMAGIC: 198 error = exec_linux_aout_prep_omagic(p, epp); 199 break; 200 } 201 if (error == 0) 202 epp->ep_emul = &emul_linux_aout; 203 return error; 204 } 205 206 /* 207 * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400 208 * is very likely not page aligned on most architectures, it is treated 209 * as an NMAGIC here. XXX 210 */ 211 212 int 213 exec_linux_aout_prep_zmagic(p, epp) 214 struct proc *p; 215 struct exec_package *epp; 216 { 217 struct exec *execp = epp->ep_hdr; 218 219 epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC); 220 epp->ep_tsize = execp->a_text; 221 epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC); 222 epp->ep_dsize = execp->a_data + execp->a_bss; 223 epp->ep_entry = execp->a_entry; 224 225 /* set up command for text segment */ 226 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 227 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, ZMAGIC), 228 VM_PROT_READ|VM_PROT_EXECUTE); 229 230 /* set up command for data segment */ 231 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 232 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, ZMAGIC), 233 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 234 235 /* set up command for bss segment */ 236 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 237 epp->ep_daddr + execp->a_data, NULLVP, 0, 238 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 239 240 return exec_aout_setup_stack(p, epp); 241 } 242 243 /* 244 * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package. 245 * Not different from the normal stuff. 246 */ 247 248 int 249 exec_linux_aout_prep_nmagic(p, epp) 250 struct proc *p; 251 struct exec_package *epp; 252 { 253 struct exec *execp = epp->ep_hdr; 254 long bsize, baddr; 255 256 epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC); 257 epp->ep_tsize = execp->a_text; 258 epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC); 259 epp->ep_dsize = execp->a_data + execp->a_bss; 260 epp->ep_entry = execp->a_entry; 261 262 /* set up command for text segment */ 263 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 264 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC), 265 VM_PROT_READ|VM_PROT_EXECUTE); 266 267 /* set up command for data segment */ 268 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 269 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC), 270 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 271 272 /* set up command for bss segment */ 273 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 274 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 275 if (bsize > 0) 276 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 277 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 278 279 return exec_aout_setup_stack(p, epp); 280 } 281 282 /* 283 * exec_aout_prep_omagic(): Prepare Linux OMAGIC package. 284 * Business as usual. 285 */ 286 287 int 288 exec_linux_aout_prep_omagic(p, epp) 289 struct proc *p; 290 struct exec_package *epp; 291 { 292 struct exec *execp = epp->ep_hdr; 293 long dsize, bsize, baddr; 294 295 epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC); 296 epp->ep_tsize = execp->a_text; 297 epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC); 298 epp->ep_dsize = execp->a_data + execp->a_bss; 299 epp->ep_entry = execp->a_entry; 300 301 /* set up command for text and data segments */ 302 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 303 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 304 LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 305 306 /* set up command for bss segment */ 307 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 308 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 309 if (bsize > 0) 310 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 311 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 312 313 /* 314 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 315 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 316 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 317 * respectively to page boundaries. 318 * Compensate `ep_dsize' for the amount of data covered by the last 319 * text page. 320 */ 321 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG); 322 epp->ep_dsize = (dsize > 0) ? dsize : 0; 323 return exec_aout_setup_stack(p, epp); 324 } 325 326 int 327 exec_linux_aout_prep_qmagic(p, epp) 328 struct proc *p; 329 struct exec_package *epp; 330 { 331 struct exec *execp = epp->ep_hdr; 332 333 epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC); 334 epp->ep_tsize = execp->a_text; 335 epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC); 336 epp->ep_dsize = execp->a_data + execp->a_bss; 337 epp->ep_entry = execp->a_entry; 338 339 /* 340 * check if vnode is in open for writing, because we want to 341 * demand-page out of it. if it is, don't do it, for various 342 * reasons 343 */ 344 if ((execp->a_text != 0 || execp->a_data != 0) && 345 epp->ep_vp->v_writecount != 0) { 346 #ifdef DIAGNOSTIC 347 if (epp->ep_vp->v_flag & VTEXT) 348 panic("exec: a VTEXT vnode has writecount != 0\n"); 349 #endif 350 return ETXTBSY; 351 } 352 epp->ep_vp->v_flag |= VTEXT; 353 354 /* set up command for text segment */ 355 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, 356 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC), 357 VM_PROT_READ|VM_PROT_EXECUTE); 358 359 /* set up command for data segment */ 360 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, 361 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC), 362 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 363 364 /* set up command for bss segment */ 365 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 366 epp->ep_daddr + execp->a_data, NULLVP, 0, 367 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 368 369 return exec_aout_setup_stack(p, epp); 370 } 371 372 /* 373 * Take advantage of the fact that all the linux binaries are compiled 374 * with gcc, and gcc sticks in the comment field a signature. Note that 375 * on SVR4 binaries, the gcc signature will follow the OS name signature, 376 * that will not be a problem. We don't bother to read in the string table, 377 * but we check all the progbits headers. 378 */ 379 static int 380 linux_elf32_signature(p, epp, eh) 381 struct proc *p; 382 struct exec_package *epp; 383 Elf32_Ehdr *eh; 384 { 385 size_t shsize = sizeof(Elf32_Shdr) * eh->e_shnum; 386 size_t i; 387 static const char signature[] = "\0GCC: (GNU) "; 388 char buf[sizeof(signature) - 1]; 389 Elf32_Shdr *sh; 390 int error; 391 392 sh = (Elf32_Shdr *) malloc(shsize, M_TEMP, M_WAITOK); 393 394 if ((error = elf32_read_from(p, epp->ep_vp, eh->e_shoff, 395 (caddr_t) sh, shsize)) != 0) 396 goto out; 397 398 for (i = 0; i < eh->e_shnum; i++) { 399 Elf32_Shdr *s = &sh[i]; 400 401 /* 402 * Identify candidates for the comment header; 403 * Header cannot have a load address, or flags and 404 * it must be large enough. 405 */ 406 if (s->sh_type != Elf32_sht_progbits || 407 s->sh_addr != 0 || 408 s->sh_flags != 0 || 409 s->sh_size < sizeof(signature) - 1) 410 continue; 411 412 if ((error = elf32_read_from(p, epp->ep_vp, s->sh_offset, 413 (caddr_t) buf, sizeof(signature) - 1)) != 0) 414 goto out; 415 416 /* 417 * error is 0, if the signatures match we are done. 418 */ 419 if (bcmp(buf, signature, sizeof(signature) - 1) == 0) 420 goto out; 421 } 422 error = EFTYPE; 423 424 out: 425 free(sh, M_TEMP); 426 return error; 427 } 428 429 int 430 linux_elf32_probe(p, epp, eh, itp, pos) 431 struct proc *p; 432 struct exec_package *epp; 433 Elf32_Ehdr *eh; 434 char *itp; 435 Elf32_Addr *pos; 436 { 437 char *bp; 438 int error; 439 size_t len; 440 441 if ((error = linux_elf32_signature(p, epp, eh)) != 0) 442 return error; 443 444 if (itp[0]) { 445 if ((error = emul_find(p, NULL, linux_emul_path, itp, &bp, 0))) 446 return error; 447 if ((error = copystr(bp, itp, MAXPATHLEN, &len))) 448 return error; 449 free(bp, M_TEMP); 450 } 451 epp->ep_emul = &emul_linux_elf; 452 *pos = ELF32_NO_ADDR; 453 return 0; 454 } 455 456 /* 457 * The Linux system call to load shared libraries, a.out version. The 458 * a.out shared libs are just files that are mapped onto a fixed 459 * address in the process' address space. The address is given in 460 * a_entry. Read in the header, set up some VM commands and run them. 461 * 462 * Yes, both text and data are mapped at once, so we're left with 463 * writeable text for the shared libs. The Linux crt0 seemed to break 464 * sometimes when data was mapped seperately. It munmapped a uselib() 465 * of ld.so by hand, which failed with shared text and data for ld.so 466 * Yuck. 467 * 468 * Because of the problem with ZMAGIC executables (text starts 469 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC 470 * shared libs are not handled very efficiently :-( 471 */ 472 473 int 474 linux_sys_uselib(p, v, retval) 475 struct proc *p; 476 void *v; 477 register_t *retval; 478 { 479 struct linux_sys_uselib_args /* { 480 syscallarg(char *) path; 481 } */ *uap = v; 482 caddr_t sg; 483 long bsize, dsize, tsize, taddr, baddr, daddr; 484 struct nameidata ni; 485 struct vnode *vp; 486 struct exec hdr; 487 struct exec_vmcmd_set vcset; 488 int rem, i, magic, error; 489 490 sg = stackgap_init(p->p_emul); 491 LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 492 493 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 494 495 if ((error = namei(&ni))) 496 return error; 497 498 vp = ni.ni_vp; 499 500 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 501 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 502 &rem, p))) { 503 vrele(vp); 504 return error; 505 } 506 507 if (rem != 0) { 508 vrele(vp); 509 return ENOEXEC; 510 } 511 512 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 513 return ENOEXEC; 514 515 magic = LINUX_N_MAGIC(&hdr); 516 taddr = hdr.a_entry & (~(NBPG - 1)); 517 tsize = hdr.a_text; 518 daddr = taddr + tsize; 519 dsize = hdr.a_data + hdr.a_bss; 520 521 if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) { 522 vrele(vp); 523 return ETXTBSY; 524 } 525 vp->v_flag |= VTEXT; 526 527 vcset.evs_cnt = 0; 528 vcset.evs_used = 0; 529 530 NEW_VMCMD(&vcset, 531 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 532 hdr.a_text + hdr.a_data, taddr, 533 vp, LINUX_N_TXTOFF(hdr, magic), 534 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 535 536 baddr = roundup(daddr + hdr.a_data, NBPG); 537 bsize = daddr + dsize - baddr; 538 if (bsize > 0) { 539 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 540 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 541 } 542 543 for (i = 0; i < vcset.evs_used && !error; i++) { 544 struct exec_vmcmd *vcp; 545 546 vcp = &vcset.evs_cmds[i]; 547 error = (*vcp->ev_proc)(p, vcp); 548 } 549 550 kill_vmcmds(&vcset); 551 552 vrele(vp); 553 554 return error; 555 } 556 557 /* 558 * Execve(2). Just check the alternate emulation path, and pass it on 559 * to the NetBSD execve(). 560 */ 561 int 562 linux_sys_execve(p, v, retval) 563 struct proc *p; 564 void *v; 565 register_t *retval; 566 { 567 struct linux_sys_execve_args /* { 568 syscallarg(char *) path; 569 syscallarg(char **) argv; 570 syscallarg(char **) envp; 571 } */ *uap = v; 572 struct sys_execve_args ap; 573 caddr_t sg; 574 575 sg = stackgap_init(p->p_emul); 576 LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 577 578 SCARG(&ap, path) = SCARG(uap, path); 579 SCARG(&ap, argp) = SCARG(uap, argp); 580 SCARG(&ap, envp) = SCARG(uap, envp); 581 582 return sys_execve(p, &ap, retval); 583 } 584
Indexes created Tue Sep 23 14:10:03 GMT 2025