1 /* $NetBSD: linux_exec_aout.c,v 1.40 2000/06/29 02:40:39 mrg Exp $ */ 2 3 /*- 4 * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas, Frank van der Linden and Eric Haszlakiewicz. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * based on exec_aout.c, sunos_exec.c and svr4_exec.c 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/malloc.h> 48 #include <sys/namei.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/exec.h> 52 #include <sys/exec_elf.h> 53 54 #include <sys/mman.h> 55 #include <sys/syscallargs.h> 56 57 #include <machine/cpu.h> 58 #include <machine/reg.h> 59 60 #include <compat/linux/common/linux_types.h> 61 #include <compat/linux/common/linux_signal.h> 62 #include <compat/linux/common/linux_util.h> 63 #include <compat/linux/common/linux_exec.h> 64 #include <compat/linux/common/linux_machdep.h> 65 #include <compat/linux/common/linux_errno.h> 66 67 #include <compat/linux/linux_syscallargs.h> 68 #include <compat/linux/linux_syscall.h> 69 70 71 static void *linux_aout_copyargs __P((struct exec_package *, 72 struct ps_strings *, void *, void *)); 73 74 #define LINUX_AOUT_AUX_ARGSIZ 2 75 76 extern char linux_sigcode[], linux_esigcode[]; 77 extern struct sysent linux_sysent[]; 78 extern char *linux_syscallnames[]; 79 80 int exec_linux_aout_prep_zmagic __P((struct proc *, struct exec_package *)); 81 int exec_linux_aout_prep_nmagic __P((struct proc *, struct exec_package *)); 82 int exec_linux_aout_prep_omagic __P((struct proc *, struct exec_package *)); 83 int exec_linux_aout_prep_qmagic __P((struct proc *, struct exec_package *)); 84 85 struct emul emul_linux_aout = { 86 "linux", 87 native_to_linux_errno, 88 linux_sendsig, 89 LINUX_SYS_syscall, 90 LINUX_SYS_MAXSYSCALL, 91 linux_sysent, 92 linux_syscallnames, 93 LINUX_AOUT_AUX_ARGSIZ, 94 linux_aout_copyargs, 95 linux_setregs, 96 linux_sigcode, 97 linux_esigcode, 98 }; 99 100 static void * 101 linux_aout_copyargs(pack, arginfo, stack, argp) 102 struct exec_package *pack; 103 struct ps_strings *arginfo; 104 void *stack; 105 void *argp; 106 { 107 char **cpp = stack; 108 char **stk = stack; 109 char *dp, *sp; 110 size_t len; 111 void *nullp = NULL; 112 int argc = arginfo->ps_nargvstr; 113 int envc = arginfo->ps_nenvstr; 114 115 if (copyout(&argc, cpp++, sizeof(argc))) 116 return NULL; 117 118 /* leave room for envp and argv */ 119 cpp += 2; 120 if (copyout(&cpp, &stk[1], sizeof (cpp))) 121 return NULL; 122 123 dp = (char *) (cpp + argc + envc + 2); 124 sp = argp; 125 126 /* XXX don't copy them out, remap them! */ 127 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 128 129 for (; --argc >= 0; sp += len, dp += len) 130 if (copyout(&dp, cpp++, sizeof(dp)) || 131 copyoutstr(sp, dp, ARG_MAX, &len)) 132 return NULL; 133 134 if (copyout(&nullp, cpp++, sizeof(nullp))) 135 return NULL; 136 137 if (copyout(&cpp, &stk[2], sizeof (cpp))) 138 return NULL; 139 140 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 141 142 for (; --envc >= 0; sp += len, dp += len) 143 if (copyout(&dp, cpp++, sizeof(dp)) || 144 copyoutstr(sp, dp, ARG_MAX, &len)) 145 return NULL; 146 147 if (copyout(&nullp, cpp++, sizeof(nullp))) 148 return NULL; 149 150 return cpp; 151 } 152 153 int 154 exec_linux_aout_makecmds(p, epp) 155 struct proc *p; 156 struct exec_package *epp; 157 { 158 struct exec *linux_ep = epp->ep_hdr; 159 int machtype, magic; 160 int error = ENOEXEC; 161 162 magic = LINUX_N_MAGIC(linux_ep); 163 machtype = LINUX_N_MACHTYPE(linux_ep); 164 165 166 if (machtype != LINUX_MID_MACHINE) 167 return (ENOEXEC); 168 169 switch (magic) { 170 case QMAGIC: 171 error = exec_linux_aout_prep_qmagic(p, epp); 172 break; 173 case ZMAGIC: 174 error = exec_linux_aout_prep_zmagic(p, epp); 175 break; 176 case NMAGIC: 177 error = exec_linux_aout_prep_nmagic(p, epp); 178 break; 179 case OMAGIC: 180 error = exec_linux_aout_prep_omagic(p, epp); 181 break; 182 } 183 if (error == 0) 184 epp->ep_emul = &emul_linux_aout; 185 return error; 186 } 187 188 /* 189 * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400 190 * is very likely not page aligned on most architectures, it is treated 191 * as an NMAGIC here. XXX 192 */ 193 194 int 195 exec_linux_aout_prep_zmagic(p, epp) 196 struct proc *p; 197 struct exec_package *epp; 198 { 199 struct exec *execp = epp->ep_hdr; 200 201 epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC); 202 epp->ep_tsize = execp->a_text; 203 epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC); 204 epp->ep_dsize = execp->a_data + execp->a_bss; 205 epp->ep_entry = execp->a_entry; 206 207 /* set up command for text segment */ 208 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 209 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, ZMAGIC), 210 VM_PROT_READ|VM_PROT_EXECUTE); 211 212 /* set up command for data segment */ 213 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 214 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, ZMAGIC), 215 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 216 217 /* set up command for bss segment */ 218 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 219 epp->ep_daddr + execp->a_data, NULLVP, 0, 220 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 221 222 return exec_aout_setup_stack(p, epp); 223 } 224 225 /* 226 * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package. 227 * Not different from the normal stuff. 228 */ 229 230 int 231 exec_linux_aout_prep_nmagic(p, epp) 232 struct proc *p; 233 struct exec_package *epp; 234 { 235 struct exec *execp = epp->ep_hdr; 236 long bsize, baddr; 237 238 epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC); 239 epp->ep_tsize = execp->a_text; 240 epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC); 241 epp->ep_dsize = execp->a_data + execp->a_bss; 242 epp->ep_entry = execp->a_entry; 243 244 /* set up command for text segment */ 245 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 246 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC), 247 VM_PROT_READ|VM_PROT_EXECUTE); 248 249 /* set up command for data segment */ 250 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 251 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC), 252 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 253 254 /* set up command for bss segment */ 255 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 256 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 257 if (bsize > 0) 258 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 259 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 260 261 return exec_aout_setup_stack(p, epp); 262 } 263 264 /* 265 * exec_aout_prep_omagic(): Prepare Linux OMAGIC package. 266 * Business as usual. 267 */ 268 269 int 270 exec_linux_aout_prep_omagic(p, epp) 271 struct proc *p; 272 struct exec_package *epp; 273 { 274 struct exec *execp = epp->ep_hdr; 275 long dsize, bsize, baddr; 276 277 epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC); 278 epp->ep_tsize = execp->a_text; 279 epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC); 280 epp->ep_dsize = execp->a_data + execp->a_bss; 281 epp->ep_entry = execp->a_entry; 282 283 /* set up command for text and data segments */ 284 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 285 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 286 LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 287 288 /* set up command for bss segment */ 289 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 290 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 291 if (bsize > 0) 292 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 293 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 294 295 /* 296 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 297 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 298 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 299 * respectively to page boundaries. 300 * Compensate `ep_dsize' for the amount of data covered by the last 301 * text page. 302 */ 303 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG); 304 epp->ep_dsize = (dsize > 0) ? dsize : 0; 305 return exec_aout_setup_stack(p, epp); 306 } 307 308 int 309 exec_linux_aout_prep_qmagic(p, epp) 310 struct proc *p; 311 struct exec_package *epp; 312 { 313 struct exec *execp = epp->ep_hdr; 314 315 epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC); 316 epp->ep_tsize = execp->a_text; 317 epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC); 318 epp->ep_dsize = execp->a_data + execp->a_bss; 319 epp->ep_entry = execp->a_entry; 320 321 /* 322 * check if vnode is in open for writing, because we want to 323 * demand-page out of it. if it is, don't do it, for various 324 * reasons 325 */ 326 if ((execp->a_text != 0 || execp->a_data != 0) && 327 epp->ep_vp->v_writecount != 0) { 328 #ifdef DIAGNOSTIC 329 if (epp->ep_vp->v_flag & VTEXT) 330 panic("exec: a VTEXT vnode has writecount != 0\n"); 331 #endif 332 return ETXTBSY; 333 } 334 vn_marktext(epp->ep_vp); 335 336 /* set up command for text segment */ 337 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, 338 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC), 339 VM_PROT_READ|VM_PROT_EXECUTE); 340 341 /* set up command for data segment */ 342 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, 343 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC), 344 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 345 346 /* set up command for bss segment */ 347 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 348 epp->ep_daddr + execp->a_data, NULLVP, 0, 349 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 350 351 return exec_aout_setup_stack(p, epp); 352 } 353 354 /* 355 * The Linux system call to load shared libraries, a.out version. The 356 * a.out shared libs are just files that are mapped onto a fixed 357 * address in the process' address space. The address is given in 358 * a_entry. Read in the header, set up some VM commands and run them. 359 * 360 * Yes, both text and data are mapped at once, so we're left with 361 * writeable text for the shared libs. The Linux crt0 seemed to break 362 * sometimes when data was mapped seperately. It munmapped a uselib() 363 * of ld.so by hand, which failed with shared text and data for ld.so 364 * Yuck. 365 * 366 * Because of the problem with ZMAGIC executables (text starts 367 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC 368 * shared libs are not handled very efficiently :-( 369 */ 370 371 int 372 linux_sys_uselib(p, v, retval) 373 struct proc *p; 374 void *v; 375 register_t *retval; 376 { 377 struct linux_sys_uselib_args /* { 378 syscallarg(const char *) path; 379 } */ *uap = v; 380 caddr_t sg; 381 long bsize, dsize, tsize, taddr, baddr, daddr; 382 struct nameidata ni; 383 struct vnode *vp; 384 struct exec hdr; 385 struct exec_vmcmd_set vcset; 386 int i, magic, error; 387 size_t rem; 388 389 sg = stackgap_init(p->p_emul); 390 LINUX_CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 391 392 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 393 394 if ((error = namei(&ni))) 395 return error; 396 397 vp = ni.ni_vp; 398 399 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 400 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 401 &rem, p))) { 402 vrele(vp); 403 return error; 404 } 405 406 if (rem != 0) { 407 vrele(vp); 408 return ENOEXEC; 409 } 410 411 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 412 return ENOEXEC; 413 414 magic = LINUX_N_MAGIC(&hdr); 415 taddr = hdr.a_entry & (~(NBPG - 1)); 416 tsize = hdr.a_text; 417 daddr = taddr + tsize; 418 dsize = hdr.a_data + hdr.a_bss; 419 420 if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) { 421 vrele(vp); 422 return ETXTBSY; 423 } 424 vn_marktext(vp); 425 426 vcset.evs_cnt = 0; 427 vcset.evs_used = 0; 428 429 NEW_VMCMD(&vcset, 430 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 431 hdr.a_text + hdr.a_data, taddr, 432 vp, LINUX_N_TXTOFF(hdr, magic), 433 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 434 435 baddr = roundup(daddr + hdr.a_data, NBPG); 436 bsize = daddr + dsize - baddr; 437 if (bsize > 0) { 438 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 439 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 440 } 441 442 for (i = 0; i < vcset.evs_used && !error; i++) { 443 struct exec_vmcmd *vcp; 444 445 vcp = &vcset.evs_cmds[i]; 446 error = (*vcp->ev_proc)(p, vcp); 447 } 448 449 kill_vmcmds(&vcset); 450 451 vrele(vp); 452 453 return error; 454 } 455