1 /* $NetBSD: linux_exec_aout.c,v 1.12 1995/10/07 06:27:00 mycroft 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 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/proc.h> 37 #include <sys/malloc.h> 38 #include <sys/namei.h> 39 #include <sys/vnode.h> 40 #include <sys/exec_elf.h> 41 42 #include <sys/mman.h> 43 #include <vm/vm.h> 44 #include <vm/vm_param.h> 45 #include <vm/vm_map.h> 46 47 #include <machine/cpu.h> 48 #include <machine/reg.h> 49 #include <machine/exec.h> 50 #include <machine/linux_machdep.h> 51 52 #include <compat/linux/linux_types.h> 53 #include <compat/linux/linux_syscall.h> 54 #include <compat/linux/linux_signal.h> 55 #include <compat/linux/linux_syscallargs.h> 56 #include <compat/linux/linux_util.h> 57 #include <compat/linux/linux_exec.h> 58 59 static void *linux_aout_copyargs __P((struct exec_package *, 60 struct ps_strings *, void *, void *)); 61 62 #define LINUX_AOUT_AUX_ARGSIZ 2 63 #define LINUX_ELF_AUX_ARGSIZ (sizeof(AuxInfo) * 8 / sizeof(char *)) 64 65 66 const char linux_emul_path[] = "/emul/linux"; 67 extern int linux_error[]; 68 extern char linux_sigcode[], linux_esigcode[]; 69 extern struct sysent linux_sysent[]; 70 extern char *linux_syscallnames[]; 71 72 struct emul emul_linux_aout = { 73 "linux", 74 linux_error, 75 linux_sendsig, 76 LINUX_SYS_syscall, 77 LINUX_SYS_MAXSYSCALL, 78 linux_sysent, 79 linux_syscallnames, 80 LINUX_AOUT_AUX_ARGSIZ, 81 linux_aout_copyargs, 82 setregs, 83 linux_sigcode, 84 linux_esigcode, 85 }; 86 87 struct emul emul_linux_elf = { 88 "linux", 89 linux_error, 90 linux_sendsig, 91 LINUX_SYS_syscall, 92 LINUX_SYS_MAXSYSCALL, 93 linux_sysent, 94 linux_syscallnames, 95 LINUX_ELF_AUX_ARGSIZ, 96 elf_copyargs, 97 setregs, 98 linux_sigcode, 99 linux_esigcode, 100 }; 101 102 103 static void * 104 linux_aout_copyargs(pack, arginfo, stack, argp) 105 struct exec_package *pack; 106 struct ps_strings *arginfo; 107 void *stack; 108 void *argp; 109 { 110 char **cpp = stack; 111 char **stk = stack; 112 char *dp, *sp; 113 size_t len; 114 void *nullp = NULL; 115 int argc = arginfo->ps_nargvstr; 116 int envc = arginfo->ps_nenvstr; 117 118 if (copyout(&argc, cpp++, sizeof(argc))) 119 return NULL; 120 121 /* leave room for envp and argv */ 122 cpp += 2; 123 if (copyout(&cpp, &stk[1], sizeof (cpp))) 124 return NULL; 125 126 dp = (char *) (cpp + argc + envc + 2); 127 sp = argp; 128 129 /* XXX don't copy them out, remap them! */ 130 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 131 132 for (; --argc >= 0; sp += len, dp += len) 133 if (copyout(&dp, cpp++, sizeof(dp)) || 134 copyoutstr(sp, dp, ARG_MAX, &len)) 135 return NULL; 136 137 if (copyout(&nullp, cpp++, sizeof(nullp))) 138 return NULL; 139 140 if (copyout(&cpp, &stk[2], sizeof (cpp))) 141 return NULL; 142 143 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 144 145 for (; --envc >= 0; sp += len, dp += len) 146 if (copyout(&dp, cpp++, sizeof(dp)) || 147 copyoutstr(sp, dp, ARG_MAX, &len)) 148 return NULL; 149 150 if (copyout(&nullp, cpp++, sizeof(nullp))) 151 return NULL; 152 153 return cpp; 154 } 155 156 int 157 exec_linux_aout_makecmds(p, epp) 158 struct proc *p; 159 struct exec_package *epp; 160 { 161 struct exec *linux_ep = epp->ep_hdr; 162 int machtype, magic; 163 int error = ENOEXEC; 164 165 magic = LINUX_N_MAGIC(linux_ep); 166 machtype = LINUX_N_MACHTYPE(linux_ep); 167 168 169 if (machtype != LINUX_MID_MACHINE) 170 return (ENOEXEC); 171 172 switch (magic) { 173 case QMAGIC: 174 error = exec_linux_aout_prep_qmagic(p, epp); 175 break; 176 case ZMAGIC: 177 error = exec_linux_aout_prep_zmagic(p, epp); 178 break; 179 case NMAGIC: 180 error = exec_linux_aout_prep_nmagic(p, epp); 181 break; 182 case OMAGIC: 183 error = exec_linux_aout_prep_omagic(p, epp); 184 break; 185 } 186 if (error == 0) 187 epp->ep_emul = &emul_linux_aout; 188 return error; 189 } 190 191 /* 192 * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400 193 * is very likely not page aligned on most architectures, it is treated 194 * as an NMAGIC here. XXX 195 */ 196 197 int 198 exec_linux_aout_prep_zmagic(p, epp) 199 struct proc *p; 200 struct exec_package *epp; 201 { 202 struct exec *execp = epp->ep_hdr; 203 204 epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC); 205 epp->ep_tsize = execp->a_text; 206 epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC); 207 epp->ep_dsize = execp->a_data + execp->a_bss; 208 epp->ep_entry = execp->a_entry; 209 210 /* set up command for text segment */ 211 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 212 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, ZMAGIC), 213 VM_PROT_READ|VM_PROT_EXECUTE); 214 215 /* set up command for data segment */ 216 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 217 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, ZMAGIC), 218 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 219 220 /* set up command for bss segment */ 221 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 222 epp->ep_daddr + execp->a_data, NULLVP, 0, 223 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 224 225 return exec_aout_setup_stack(p, epp); 226 } 227 228 /* 229 * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package. 230 * Not different from the normal stuff. 231 */ 232 233 int 234 exec_linux_aout_prep_nmagic(p, epp) 235 struct proc *p; 236 struct exec_package *epp; 237 { 238 struct exec *execp = epp->ep_hdr; 239 long bsize, baddr; 240 241 epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC); 242 epp->ep_tsize = execp->a_text; 243 epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC); 244 epp->ep_dsize = execp->a_data + execp->a_bss; 245 epp->ep_entry = execp->a_entry; 246 247 /* set up command for text segment */ 248 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 249 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC), 250 VM_PROT_READ|VM_PROT_EXECUTE); 251 252 /* set up command for data segment */ 253 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 254 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC), 255 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 256 257 /* set up command for bss segment */ 258 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 259 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 260 if (bsize > 0) 261 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 262 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 263 264 return exec_aout_setup_stack(p, epp); 265 } 266 267 /* 268 * exec_aout_prep_omagic(): Prepare Linux OMAGIC package. 269 * Business as usual. 270 */ 271 272 int 273 exec_linux_aout_prep_omagic(p, epp) 274 struct proc *p; 275 struct exec_package *epp; 276 { 277 struct exec *execp = epp->ep_hdr; 278 long dsize, bsize, baddr; 279 280 epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC); 281 epp->ep_tsize = execp->a_text; 282 epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC); 283 epp->ep_dsize = execp->a_data + execp->a_bss; 284 epp->ep_entry = execp->a_entry; 285 286 /* set up command for text and data segments */ 287 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 288 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 289 LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 290 291 /* set up command for bss segment */ 292 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 293 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 294 if (bsize > 0) 295 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 296 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 297 298 /* 299 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 300 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 301 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 302 * respectively to page boundaries. 303 * Compensate `ep_dsize' for the amount of data covered by the last 304 * text page. 305 */ 306 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG); 307 epp->ep_dsize = (dsize > 0) ? dsize : 0; 308 return exec_aout_setup_stack(p, epp); 309 } 310 311 int 312 exec_linux_aout_prep_qmagic(p, epp) 313 struct proc *p; 314 struct exec_package *epp; 315 { 316 struct exec *execp = epp->ep_hdr; 317 318 epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC); 319 epp->ep_tsize = execp->a_text; 320 epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC); 321 epp->ep_dsize = execp->a_data + execp->a_bss; 322 epp->ep_entry = execp->a_entry; 323 324 /* 325 * check if vnode is in open for writing, because we want to 326 * demand-page out of it. if it is, don't do it, for various 327 * reasons 328 */ 329 if ((execp->a_text != 0 || execp->a_data != 0) && 330 epp->ep_vp->v_writecount != 0) { 331 #ifdef DIAGNOSTIC 332 if (epp->ep_vp->v_flag & VTEXT) 333 panic("exec: a VTEXT vnode has writecount != 0\n"); 334 #endif 335 return ETXTBSY; 336 } 337 epp->ep_vp->v_flag |= VTEXT; 338 339 /* set up command for text segment */ 340 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, 341 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC), 342 VM_PROT_READ|VM_PROT_EXECUTE); 343 344 /* set up command for data segment */ 345 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, 346 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC), 347 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 348 349 /* set up command for bss segment */ 350 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 351 epp->ep_daddr + execp->a_data, NULLVP, 0, 352 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 353 354 return exec_aout_setup_stack(p, epp); 355 } 356 357 int 358 linux_elf_probe(p, epp, itp, pos) 359 struct proc *p; 360 struct exec_package *epp; 361 char *itp; 362 u_long *pos; 363 { 364 char *bp; 365 int error; 366 size_t len; 367 368 if (itp[0]) { 369 if ((error = emul_find(p, NULL, linux_emul_path, itp, &bp, 0))) 370 return error; 371 if ((error = copystr(bp, itp, MAXPATHLEN, &len))) 372 return error; 373 free(bp, M_TEMP); 374 } 375 epp->ep_emul = &emul_linux_elf; 376 *pos = ELF32_NO_ADDR; 377 return 0; 378 } 379 380 /* 381 * The Linux system call to load shared libraries, a.out version. The 382 * a.out shared libs are just files that are mapped onto a fixed 383 * address in the process' address space. The address is given in 384 * a_entry. Read in the header, set up some VM commands and run them. 385 * 386 * Yes, both text and data are mapped at once, so we're left with 387 * writeable text for the shared libs. The Linux crt0 seemed to break 388 * sometimes when data was mapped seperately. It munmapped a uselib() 389 * of ld.so by hand, which failed with shared text and data for ld.so 390 * Yuck. 391 * 392 * Because of the problem with ZMAGIC executables (text starts 393 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC 394 * shared libs are not handled very efficiently :-( 395 */ 396 397 int 398 linux_sys_uselib(p, v, retval) 399 struct proc *p; 400 void *v; 401 register_t *retval; 402 { 403 struct linux_sys_uselib_args /* { 404 syscallarg(char *) path; 405 } */ *uap = v; 406 caddr_t sg; 407 long bsize, dsize, tsize, taddr, baddr, daddr; 408 struct nameidata ni; 409 struct vnode *vp; 410 struct exec hdr; 411 struct exec_vmcmd_set vcset; 412 int rem, i, magic, error; 413 414 sg = stackgap_init(p->p_emul); 415 LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 416 417 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 418 419 if ((error = namei(&ni))) 420 return error; 421 422 vp = ni.ni_vp; 423 424 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 425 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 426 &rem, p))) { 427 vrele(vp); 428 return error; 429 } 430 431 if (rem != 0) { 432 vrele(vp); 433 return ENOEXEC; 434 } 435 436 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 437 return ENOEXEC; 438 439 magic = LINUX_N_MAGIC(&hdr); 440 taddr = hdr.a_entry & (~(NBPG - 1)); 441 tsize = hdr.a_text; 442 daddr = taddr + tsize; 443 dsize = hdr.a_data + hdr.a_bss; 444 445 if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) { 446 vrele(vp); 447 return ETXTBSY; 448 } 449 vp->v_flag |= VTEXT; 450 451 vcset.evs_cnt = 0; 452 vcset.evs_used = 0; 453 454 NEW_VMCMD(&vcset, 455 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 456 hdr.a_text + hdr.a_data, taddr, 457 vp, LINUX_N_TXTOFF(hdr, magic), 458 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 459 460 baddr = roundup(daddr + hdr.a_data, NBPG); 461 bsize = daddr + dsize - baddr; 462 if (bsize > 0) { 463 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 464 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 465 } 466 467 for (i = 0; i < vcset.evs_used && !error; i++) { 468 struct exec_vmcmd *vcp; 469 470 vcp = &vcset.evs_cmds[i]; 471 error = (*vcp->ev_proc)(p, vcp); 472 } 473 474 kill_vmcmds(&vcset); 475 476 vrele(vp); 477 478 return error; 479 } 480 481 /* 482 * Execve(2). Just check the alternate emulation path, and pass it on 483 * to the NetBSD execve(). 484 */ 485 int 486 linux_sys_execve(p, v, retval) 487 struct proc *p; 488 void *v; 489 register_t *retval; 490 { 491 struct linux_sys_execve_args /* { 492 syscallarg(char *) path; 493 syscallarg(char **) argv; 494 syscallarg(char **) envp; 495 } */ *uap = v; 496 caddr_t sg; 497 498 sg = stackgap_init(p->p_emul); 499 LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 500 501 return sys_execve(p, uap, retval); 502 } 503