linux_exec.c revision 1.6
1/* $NetBSD: linux_exec.c,v 1.6 1995/06/11 14:56:47 fvdl Exp $ */ 2 3/* 4 * Copyright (c) 1995 Frank van der Linden 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed for the NetBSD Project 18 * by Frank van der Linden 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 * 33 * based on kern/exec_aout.c and compat/sunos/sunos_exec.c 34 */ 35 36#include <sys/param.h> 37#include <sys/systm.h> 38#include <sys/filedesc.h> 39#include <sys/kernel.h> 40#include <sys/proc.h> 41#include <sys/mount.h> 42#include <sys/malloc.h> 43#include <sys/namei.h> 44#include <sys/vnode.h> 45#include <sys/file.h> 46#include <sys/resourcevar.h> 47#include <sys/wait.h> 48 49#include <sys/mman.h> 50#include <vm/vm.h> 51#include <vm/vm_param.h> 52#include <vm/vm_map.h> 53#include <vm/vm_kern.h> 54#include <vm/vm_pager.h> 55 56#include <machine/cpu.h> 57#include <machine/reg.h> 58#include <machine/exec.h> 59#include <machine/linux_machdep.h> 60 61#include <compat/linux/linux_types.h> 62#include <compat/linux/linux_syscall.h> 63#include <compat/linux/linux_syscallargs.h> 64#include <compat/linux/linux_util.h> 65#include <compat/linux/linux_exec.h> 66 67struct elf_args { 68 u_long arg_entry; /* progran entry point */ 69 u_long arg_interp; /* Interpreter load address */ 70 u_long arg_phaddr; /* program header address */ 71 u_long arg_phentsize; /* Size of program header */ 72 u_long arg_phnum; /* Number of program headers */ 73}; 74 75static void *linux_aout_copyargs __P((struct exec_package *, 76 struct ps_strings *, void *, void *)); 77static void *linux_elf_copyargs __P((struct exec_package *, struct ps_strings *, 78 void *, void *)); 79static int linux_elf_check_header __P((Elf32_Ehdr *, int)); 80static void linux_elf_load_psection __P((struct exec_vmcmd_set *, 81 struct vnode *, Elf32_Phdr *, u_long *, u_long *, int *)); 82static int linux_elf_set_segment __P((struct exec_package *, u_long, u_long, 83 int)); 84static int linux_elf_read_from __P((struct vnode *, u_long, struct proc *, 85 caddr_t, int)); 86static int linux_elf_load_file __P((struct proc *, char *, 87 struct exec_vmcmd_set *, u_long *, struct elf_args *, u_long *)); 88 89#ifdef DEBUG_EXEC_LINUX_ELF 90#define DPRINTF(x) printf x 91#else 92#define DPRINTF(x) 93#endif 94 95#define LINUX_ELF_ALIGN(a, b) ((a) & ~((b) - 1)) 96#define LINUX_ELF_AUX_ARGSIZ (sizeof(AuxInfo) * 8 / sizeof(char *)) 97#define LINUX_AOUT_AUX_ARGSIZ 2 98 99extern int linux_error[]; 100extern struct sysent linux_sysent[]; 101extern char *linux_syscallnames[]; 102 103struct emul emul_linux_aout = { 104 "linux", 105 linux_error, 106 linux_sendsig, 107 LINUX_SYS_syscall, 108 LINUX_SYS_MAXSYSCALL, 109 linux_sysent, 110 linux_syscallnames, 111 LINUX_AOUT_AUX_ARGSIZ, 112 linux_aout_copyargs, 113 setregs, 114 linux_sigcode, 115 linux_esigcode, 116}; 117 118struct emul emul_linux_elf = { 119 "linux", 120 linux_error, 121 linux_sendsig, 122 LINUX_SYS_syscall, 123 LINUX_SYS_MAXSYSCALL, 124 linux_sysent, 125 linux_syscallnames, 126 LINUX_ELF_AUX_ARGSIZ, 127 linux_elf_copyargs, 128 setregs, 129 linux_sigcode, 130 linux_esigcode, 131}; 132 133 134static void * 135linux_aout_copyargs(pack, arginfo, stack, argp) 136 struct exec_package *pack; 137 struct ps_strings *arginfo; 138 void *stack; 139 void *argp; 140{ 141 char **cpp = stack; 142 char **stk = stack; 143 char *dp, *sp; 144 size_t len; 145 void *nullp = NULL; 146 int argc = arginfo->ps_nargvstr; 147 int envc = arginfo->ps_nenvstr; 148 149 if (copyout(&argc, cpp++, sizeof(argc))) 150 return NULL; 151 152 /* leave room for envp and argv */ 153 cpp += 2; 154 if (copyout(&cpp, &stk[1], sizeof (cpp))) 155 return NULL; 156 157 dp = (char *) (cpp + argc + envc + 2); 158 sp = argp; 159 160 /* XXX don't copy them out, remap them! */ 161 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 162 163 for (; --argc >= 0; sp += len, dp += len) 164 if (copyout(&dp, cpp++, sizeof(dp)) || 165 copyoutstr(sp, dp, ARG_MAX, &len)) 166 return NULL; 167 168 if (copyout(&nullp, cpp++, sizeof(nullp))) 169 return NULL; 170 171 if (copyout(&cpp, &stk[2], sizeof (cpp))) 172 return NULL; 173 174 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 175 176 for (; --envc >= 0; sp += len, dp += len) 177 if (copyout(&dp, cpp++, sizeof(dp)) || 178 copyoutstr(sp, dp, ARG_MAX, &len)) 179 return NULL; 180 181 if (copyout(&nullp, cpp++, sizeof(nullp))) 182 return NULL; 183 184 return cpp; 185} 186 187static void * 188linux_elf_copyargs(pack, arginfo, stack, argp) 189 struct exec_package *pack; 190 struct ps_strings *arginfo; 191 void *stack; 192 void *argp; 193{ 194 char **cpp = stack; 195 char *dp, *sp; 196 size_t len; 197 void *nullp = NULL; 198 int argc = arginfo->ps_nargvstr; 199 int envc = arginfo->ps_nenvstr; 200 AuxInfo *a; 201 struct elf_args *ap; 202 203 if (copyout(&argc, cpp++, sizeof(argc))) 204 return NULL; 205 206 dp = (char *) (cpp + argc + envc + 2 + pack->ep_emul->e_arglen); 207 sp = argp; 208 209 /* XXX don't copy them out, remap them! */ 210 arginfo->ps_argvstr = cpp; /* remember location of argv for later */ 211 212 for (; --argc >= 0; sp += len, dp += len) 213 if (copyout(&dp, cpp++, sizeof(dp)) || 214 copyoutstr(sp, dp, ARG_MAX, &len)) 215 return NULL; 216 217 if (copyout(&nullp, cpp++, sizeof(nullp))) 218 return NULL; 219 220 arginfo->ps_envstr = cpp; /* remember location of envp for later */ 221 222 for (; --envc >= 0; sp += len, dp += len) 223 if (copyout(&dp, cpp++, sizeof(dp)) || 224 copyoutstr(sp, dp, ARG_MAX, &len)) 225 return NULL; 226 227 if (copyout(&nullp, cpp++, sizeof(nullp))) 228 return NULL; 229 230 /* 231 * Push extra arguments on the stack needed by dynamically 232 * linked binaries 233 */ 234 a = (AuxInfo *) cpp; 235 if ((ap = (struct elf_args *) pack->ep_emul_arg)) { 236 237 DPRINTF(("phaddr=0x%x, phsize=%d, phnum=%d, interp=0x%x, ", 238 ap->arg_phaddr, ap->arg_phentsize, ap->arg_phnum, 239 ap->arg_interp)); 240 DPRINTF((" entry=0x%x\n", ap->arg_entry)); 241 242 a->au_id = AUX_phdr; 243 a->au_v = ap->arg_phaddr; 244 a++; 245 246 a->au_id = AUX_phent; 247 a->au_v = ap->arg_phentsize; 248 a++; 249 250 a->au_id = AUX_phnum; 251 a->au_v = ap->arg_phnum; 252 a++; 253 254 a->au_id = AUX_pagesz; 255 a->au_v = NBPG; 256 a++; 257 258 a->au_id = AUX_base; 259 a->au_v = ap->arg_interp; 260 a++; 261 262 a->au_id = AUX_flags; 263 a->au_v = 0; 264 a++; 265 266 a->au_id = AUX_entry; 267 a->au_v = ap->arg_entry; 268 a++; 269 270 a->au_id = AUX_null; 271 a->au_v = 0; 272 a++; 273 274 free((char *) ap, M_TEMP); 275 } 276 return a; 277} 278 279#ifdef DEBUG_EXEC_LINUX_ELF 280static void 281print_Ehdr(e) 282 Elf32_Ehdr *e; 283{ 284 printf("e_ident %s, ", e->e_ident); 285 printf("e_type %d, ", e->e_type); 286 printf("e_machine %d, ", e->e_machine); 287 printf("e_version %ld, ", e->e_version); 288 printf("e_entry %lx, ", e->e_entry); 289 printf("e_phoff %lx, ", e->e_phoff); 290 printf("e_shoff %lx, ", e->e_shoff); 291 printf("e_flags %lx, ", e->e_flags); 292 printf("e_ehsize %d, ", e->e_ehsize); 293 printf("e_phentsize %d, ", e->e_phentsize); 294 printf("e_phnum %d, ", e->e_phnum); 295 printf("e_shentsize %d, ", e->e_shentsize); 296 printf("e_shnum %d, ", e->e_shnum); 297 printf("e_shstrndx %d\n", e->e_shstrndx); 298} 299 300 301static void 302print_Phdr(p) 303 Elf32_Phdr *p; 304{ 305 static char *types[] = 306 { 307 "null", "load", "dynamic", "interp", 308 "note", "shlib", "phdr", "entry7" 309 }; 310 311 printf("p_type %ld [%s], ", p->p_type, types[p->p_type & 7]); 312 printf("p_offset %lx, ", p->p_offset); 313 printf("p_vaddr %lx, ", p->p_vaddr); 314 printf("p_paddr %lx, ", p->p_paddr); 315 printf("p_filesz %ld, ", p->p_filesz); 316 printf("p_memsz %ld, ", p->p_memsz); 317 printf("p_flags %lx, ", p->p_flags); 318 printf("p_align %ld\n", p->p_align); 319} 320#endif 321 322int 323exec_linux_aout_makecmds(p, epp) 324 struct proc *p; 325 struct exec_package *epp; 326{ 327 struct exec *linux_ep = epp->ep_hdr; 328 int machtype, magic; 329 int error = ENOEXEC; 330 331 magic = LINUX_N_MAGIC(linux_ep); 332 machtype = LINUX_N_MACHTYPE(linux_ep); 333 334 335 if (machtype != LINUX_MID_MACHINE) 336 return (ENOEXEC); 337 338 switch (magic) { 339 case QMAGIC: 340 error = exec_linux_aout_prep_qmagic(p, epp); 341 break; 342 case ZMAGIC: 343 error = exec_linux_aout_prep_zmagic(p, epp); 344 break; 345 case NMAGIC: 346 error = exec_linux_aout_prep_nmagic(p, epp); 347 break; 348 case OMAGIC: 349 error = exec_linux_aout_prep_omagic(p, epp); 350 break; 351 } 352 if (error == 0) 353 epp->ep_emul = &emul_linux_aout; 354 return error; 355} 356 357/* 358 * Since text starts at 0x400 in Linux ZMAGIC executables, and 0x400 359 * is very likely not page aligned on most architectures, it is treated 360 * as an NMAGIC here. XXX 361 */ 362 363int 364exec_linux_aout_prep_zmagic(p, epp) 365 struct proc *p; 366 struct exec_package *epp; 367{ 368 struct exec *execp = epp->ep_hdr; 369 370 epp->ep_taddr = LINUX_N_TXTADDR(*execp, ZMAGIC); 371 epp->ep_tsize = execp->a_text; 372 epp->ep_daddr = LINUX_N_DATADDR(*execp, ZMAGIC); 373 epp->ep_dsize = execp->a_data + execp->a_bss; 374 epp->ep_entry = execp->a_entry; 375 376 /* set up command for text segment */ 377 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 378 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, ZMAGIC), 379 VM_PROT_READ|VM_PROT_EXECUTE); 380 381 /* set up command for data segment */ 382 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 383 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, ZMAGIC), 384 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 385 386 /* set up command for bss segment */ 387 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 388 epp->ep_daddr + execp->a_data, NULLVP, 0, 389 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 390 391 return exec_aout_setup_stack(p, epp); 392} 393 394/* 395 * exec_aout_prep_nmagic(): Prepare Linux NMAGIC package. 396 * Not different from the normal stuff. 397 */ 398 399int 400exec_linux_aout_prep_nmagic(p, epp) 401 struct proc *p; 402 struct exec_package *epp; 403{ 404 struct exec *execp = epp->ep_hdr; 405 long bsize, baddr; 406 407 epp->ep_taddr = LINUX_N_TXTADDR(*execp, NMAGIC); 408 epp->ep_tsize = execp->a_text; 409 epp->ep_daddr = LINUX_N_DATADDR(*execp, NMAGIC); 410 epp->ep_dsize = execp->a_data + execp->a_bss; 411 epp->ep_entry = execp->a_entry; 412 413 /* set up command for text segment */ 414 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_text, 415 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, NMAGIC), 416 VM_PROT_READ|VM_PROT_EXECUTE); 417 418 /* set up command for data segment */ 419 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, execp->a_data, 420 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, NMAGIC), 421 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 422 423 /* set up command for bss segment */ 424 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 425 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 426 if (bsize > 0) 427 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 428 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 429 430 return exec_aout_setup_stack(p, epp); 431} 432 433/* 434 * exec_aout_prep_omagic(): Prepare Linux OMAGIC package. 435 * Business as usual. 436 */ 437 438int 439exec_linux_aout_prep_omagic(p, epp) 440 struct proc *p; 441 struct exec_package *epp; 442{ 443 struct exec *execp = epp->ep_hdr; 444 long dsize, bsize, baddr; 445 446 epp->ep_taddr = LINUX_N_TXTADDR(*execp, OMAGIC); 447 epp->ep_tsize = execp->a_text; 448 epp->ep_daddr = LINUX_N_DATADDR(*execp, OMAGIC); 449 epp->ep_dsize = execp->a_data + execp->a_bss; 450 epp->ep_entry = execp->a_entry; 451 452 /* set up command for text and data segments */ 453 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, 454 execp->a_text + execp->a_data, epp->ep_taddr, epp->ep_vp, 455 LINUX_N_TXTOFF(*execp, OMAGIC), VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 456 457 /* set up command for bss segment */ 458 baddr = roundup(epp->ep_daddr + execp->a_data, NBPG); 459 bsize = epp->ep_daddr + epp->ep_dsize - baddr; 460 if (bsize > 0) 461 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, bsize, baddr, 462 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 463 464 /* 465 * Make sure (# of pages) mapped above equals (vm_tsize + vm_dsize); 466 * obreak(2) relies on this fact. Both `vm_tsize' and `vm_dsize' are 467 * computed (in execve(2)) by rounding *up* `ep_tsize' and `ep_dsize' 468 * respectively to page boundaries. 469 * Compensate `ep_dsize' for the amount of data covered by the last 470 * text page. 471 */ 472 dsize = epp->ep_dsize + execp->a_text - roundup(execp->a_text, NBPG); 473 epp->ep_dsize = (dsize > 0) ? dsize : 0; 474 return exec_aout_setup_stack(p, epp); 475} 476 477int 478exec_linux_aout_prep_qmagic(p, epp) 479 struct proc *p; 480 struct exec_package *epp; 481{ 482 struct exec *execp = epp->ep_hdr; 483 484 epp->ep_taddr = LINUX_N_TXTADDR(*execp, QMAGIC); 485 epp->ep_tsize = execp->a_text; 486 epp->ep_daddr = LINUX_N_DATADDR(*execp, QMAGIC); 487 epp->ep_dsize = execp->a_data + execp->a_bss; 488 epp->ep_entry = execp->a_entry; 489 490 /* 491 * check if vnode is in open for writing, because we want to 492 * demand-page out of it. if it is, don't do it, for various 493 * reasons 494 */ 495 if ((execp->a_text != 0 || execp->a_data != 0) && 496 epp->ep_vp->v_writecount != 0) { 497#ifdef DIAGNOSTIC 498 if (epp->ep_vp->v_flag & VTEXT) 499 panic("exec: a VTEXT vnode has writecount != 0\n"); 500#endif 501 return ETXTBSY; 502 } 503 epp->ep_vp->v_flag |= VTEXT; 504 505 /* set up command for text segment */ 506 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_text, 507 epp->ep_taddr, epp->ep_vp, LINUX_N_TXTOFF(*execp, QMAGIC), 508 VM_PROT_READ|VM_PROT_EXECUTE); 509 510 /* set up command for data segment */ 511 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_pagedvn, execp->a_data, 512 epp->ep_daddr, epp->ep_vp, LINUX_N_DATOFF(*execp, QMAGIC), 513 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 514 515 /* set up command for bss segment */ 516 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_zero, execp->a_bss, 517 epp->ep_daddr + execp->a_data, NULLVP, 0, 518 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 519 520 return exec_aout_setup_stack(p, epp); 521} 522 523/* 524 * linux_elf_check_header(): 525 * 526 * Check header for validity; return 0 of ok ENOEXEC if error 527 */ 528static int 529linux_elf_check_header(eh, type) 530 Elf32_Ehdr *eh; 531 int type; 532{ 533#ifdef sparc 534 /* #$%@#$%@#$%! */ 535# define memcmp bcmp 536#endif 537 if (memcmp(eh->e_ident, Elf32_e_ident, Elf32_e_siz) != 0) { 538 DPRINTF(("Not an elf file\n")); 539 return ENOEXEC; 540 } 541 542 switch (eh->e_machine) { 543#ifdef i386 544 case Elf32_em_386: 545 case Elf32_em_486: 546#endif 547#ifdef sparc 548 case Elf32_em_sparc: 549#endif 550 break; 551 552 default: 553 DPRINTF(("Unsupported elf machine type %d\n", eh->e_machine)); 554 return ENOEXEC; 555 } 556 557 if (eh->e_type != type) { 558 DPRINTF(("Not an elf executable\n")); 559 return ENOEXEC; 560 } 561 562 return 0; 563} 564 565 566/* 567 * linux_elf_load_psection(): 568 * 569 * Load a psection at the appropriate address 570 */ 571static void 572linux_elf_load_psection(vcset, vp, ph, addr, size, prot) 573 struct exec_vmcmd_set *vcset; 574 struct vnode *vp; 575 Elf32_Phdr *ph; 576 u_long *addr; 577 u_long *size; 578 int *prot; 579{ 580 u_long uaddr; 581 long diff; 582 long offset; 583 u_long msize; 584 585 /* 586 * If the user specified an address, then we load there. 587 */ 588 if (*addr != ~0) { 589 uaddr = *addr + ph->p_align; 590 *addr = LINUX_ELF_ALIGN(uaddr, ph->p_align); 591 uaddr = LINUX_ELF_ALIGN(ph->p_vaddr, ph->p_align); 592 diff = ph->p_vaddr - uaddr; 593 } else { 594 uaddr = ph->p_vaddr; 595 *addr = LINUX_ELF_ALIGN(uaddr, ph->p_align); 596 diff = uaddr - *addr; 597 } 598 599 *prot |= (ph->p_flags & Elf32_pf_r) ? VM_PROT_READ : 0; 600 *prot |= (ph->p_flags & Elf32_pf_w) ? VM_PROT_WRITE : 0; 601 *prot |= (ph->p_flags & Elf32_pf_x) ? VM_PROT_EXECUTE : 0; 602 603 offset = ph->p_offset - diff; 604 *size = ph->p_filesz + diff; 605 msize = ph->p_memsz + diff; 606 607 DPRINTF(("Elf Seg@ 0x%x/0x%x sz %d/%d off 0x%x/0x%x[%d] algn 0x%x\n", 608 ph->p_vaddr, *addr, *size, msize, ph->p_offset, offset, 609 diff, ph->p_align)); 610 611 NEW_VMCMD(vcset, vmcmd_map_readvn, *size, 612 *addr, vp, offset, *prot); 613 614 /* 615 * Check if we need to extend the size of the segment 616 */ 617 { 618 u_long rm = round_page(*addr + msize); 619 u_long rf = round_page(*addr + *size); 620 if (rm != rf) { 621 DPRINTF(("zeropad 0x%x-0x%x\n", rf, rm)); 622 NEW_VMCMD(vcset, vmcmd_map_zero, rm - rf, 623 rf, NULLVP, 0, *prot); 624 *size = msize; 625 } 626 } 627} 628 629 630/* 631 * linux_elf_set_segment(): 632 * 633 * Decide if the segment is text or data, depending on the protection 634 * and set it appropriately 635 */ 636static int 637linux_elf_set_segment(epp, vaddr, size, prot) 638 struct exec_package *epp; 639 u_long vaddr; 640 u_long size; 641 int prot; 642{ 643 /* 644 * Kludge: Unfortunately the current implementation of 645 * exec package assumes a single text and data segment. 646 * In Elf we can have more, but here we limit ourselves 647 * to two and hope :-( 648 * We also assume that the text is r-x, and data is rwx. 649 */ 650 switch (prot) { 651 case (VM_PROT_READ | VM_PROT_EXECUTE): 652 if (epp->ep_tsize != ~0) { 653 DPRINTF(("More than one text segment\n")); 654 return ENOEXEC; 655 } 656 epp->ep_taddr = vaddr; 657 epp->ep_tsize = size; 658 DPRINTF(("Elf Text@ 0x%x, size %d\n", vaddr, size)); 659 break; 660 661 case (VM_PROT_READ | VM_PROT_WRITE): 662 case (VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE): 663 if (epp->ep_dsize != ~0) { 664 DPRINTF(("More than one data segment\n")); 665 return ENOEXEC; 666 } 667 epp->ep_daddr = vaddr; 668 epp->ep_dsize = size; 669 670 DPRINTF(("Elf Data@ 0x%x, size %d\n", vaddr, size)); 671 break; 672 673 default: 674 DPRINTF(("Bad protection 0%o\n", prot)); 675 return ENOEXEC; 676 } 677 return 0; 678} 679 680 681/* 682 * linux_elf_read_from(): 683 * 684 * Read from vnode into buffer at offset. 685 */ 686static int 687linux_elf_read_from(vp, off, p, buf, size) 688 struct vnode *vp; 689 u_long off; 690 struct proc *p; 691 caddr_t buf; 692 int size; 693{ 694 int error; 695 int resid; 696 697 DPRINTF(("read from 0x%x to 0x%x size %d\n", 698 off, buf, size)); 699 if ((error = vn_rdwr(UIO_READ, vp, buf, size, 700 off, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 701 &resid, p)) != 0) { 702 DPRINTF(("Bad read error %d\n", error)); 703 return error; 704 } 705 /* 706 * See if we got all of it 707 */ 708 if (resid != 0) { 709 DPRINTF(("Incomplete read for header ask=%d, rem=%d\n", 710 size, resid)); 711 return error; 712 } 713 return 0; 714} 715 716 717/* 718 * linux_elf_load_file(): 719 * 720 * Load a file (interpreter/library) pointed to by path 721 * [stolen from coff_load_shlib()]. Made slightly more generic than 722 * the svr4 version, for possible later use in linux_uselib(). 723 */ 724static int 725linux_elf_load_file(p, path, vcset, entry, ap, last) 726 struct proc *p; 727 char *path; 728 struct exec_vmcmd_set *vcset; 729 u_long *entry; 730 struct elf_args *ap; 731 u_long *last; 732{ 733 int error, i; 734 struct nameidata nd; 735 Elf32_Ehdr eh; 736 Elf32_Phdr *ph = NULL; 737 u_long phsize; 738 char *bp = NULL; 739 u_long addr = *last; 740 741 DPRINTF(("Loading file %s @ %x\n", path, addr)); 742 743 if ((error = linux_emul_find(p, NULL, linux_emul_path, path, &bp, 0)) != 0) 744 bp = NULL; 745 else 746 path = bp; 747 /* 748 * 1. open file 749 * 2. read filehdr 750 * 3. map text, data, and bss out of it using VM_* 751 */ 752 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, p); 753 /* first get the vnode */ 754 if ((error = namei(&nd)) != 0) { 755 if (bp != NULL) 756 free((char *) bp, M_TEMP); 757 return error; 758 } 759 if ((error = linux_elf_read_from(nd.ni_vp, 0, p, (caddr_t) &eh, 760 sizeof(eh))) != 0) 761 goto bad; 762 763#ifdef DEBUG_EXEC_LINUX_ELF 764 print_Ehdr(&eh); 765#endif 766 767 if ((error = linux_elf_check_header(&eh, Elf32_et_dyn)) != 0) 768 goto bad; 769 770 phsize = eh.e_phnum * sizeof(Elf32_Phdr); 771 ph = (Elf32_Phdr *) malloc(phsize, M_TEMP, M_WAITOK); 772 773 if ((error = linux_elf_read_from(nd.ni_vp, eh.e_phoff, p, 774 (caddr_t) ph, phsize)) != 0) 775 goto bad; 776 777 /* 778 * Load all the necessary sections 779 */ 780 for (i = 0; i < eh.e_phnum; i++) { 781 u_long size = 0; 782 int prot = 0; 783#ifdef DEBUG_EXEC_LINUX_ELF 784 print_Phdr(&ph[i]); 785#endif 786 787 switch (ph[i].p_type) { 788 case Elf32_pt_load: 789 linux_elf_load_psection(vcset, nd.ni_vp, &ph[i], &addr, 790 &size, &prot); 791 /* Assume that the text segment is r-x only */ 792 if ((prot & PROT_WRITE) == 0) { 793 *entry = addr + eh.e_entry; 794 ap->arg_interp = addr; 795 DPRINTF(("Interpreter@ 0x%x\n", addr)); 796 } 797 addr += size; 798 break; 799 800 case Elf32_pt_dynamic: 801 case Elf32_pt_phdr: 802 case Elf32_pt_note: 803 break; 804 805 default: 806 DPRINTF(("interp: Unexpected program header type %d\n", 807 ph[i].p_type)); 808 break; 809 } 810 } 811 812bad: 813 if (ph != NULL) 814 free((char *) ph, M_TEMP); 815 if (bp != NULL) 816 free((char *) bp, M_TEMP); 817 818 *last = addr; 819 vrele(nd.ni_vp); 820 return error; 821} 822 823 824/* 825 * exec_linux_elf_makecmds(): Prepare an Elf binary's exec package 826 * 827 * First, set of the various offsets/lengths in the exec package. 828 * 829 * Then, mark the text image busy (so it can be demand paged) or error 830 * out if this is not possible. Finally, set up vmcmds for the 831 * text, data, bss, and stack segments. 832 */ 833int 834exec_linux_elf_makecmds(p, epp) 835 struct proc *p; 836 struct exec_package *epp; 837{ 838 Elf32_Ehdr *eh = epp->ep_hdr; 839 Elf32_Phdr *ph, *pp; 840 int error; 841 int i; 842 char interp[MAXPATHLEN]; 843 u_long pos = 0; 844 u_long phsize; 845 846#ifdef DEBUG_EXEC_LINUX_ELF 847 print_Ehdr(eh); 848#endif 849 if (epp->ep_hdrvalid < sizeof(Elf32_Ehdr)) 850 return ENOEXEC; 851 852 if (linux_elf_check_header(eh, Elf32_et_exec)) 853 return ENOEXEC; 854 855 /* 856 * check if vnode is in open for writing, because we want to 857 * demand-page out of it. if it is, don't do it, for various 858 * reasons 859 */ 860 if (epp->ep_vp->v_writecount != 0) { 861#ifdef DIAGNOSTIC 862 if (epp->ep_vp->v_flag & VTEXT) 863 panic("exec: a VTEXT vnode has writecount != 0\n"); 864#endif 865 return ETXTBSY; 866 } 867 /* 868 * Allocate space to hold all the program headers, and read them 869 * from the file 870 */ 871 phsize = eh->e_phnum * sizeof(Elf32_Phdr); 872 ph = (Elf32_Phdr *) malloc(phsize, M_TEMP, M_WAITOK); 873 874 if ((error = linux_elf_read_from(epp->ep_vp, eh->e_phoff, p, 875 (caddr_t) ph, phsize)) != 0) 876 goto bad; 877 878 epp->ep_tsize = ~0; 879 epp->ep_dsize = ~0; 880 881 interp[0] = '\0'; 882 883 /* 884 * Load all the necessary sections 885 */ 886 for (i = 0; i < eh->e_phnum; i++) { 887 u_long addr = ~0, size = 0; 888 int prot = 0; 889 890 pp = &ph[i]; 891#ifdef DEBUG_EXEC_LINUX_ELF 892 print_Phdr(pp); 893#endif 894 895 switch (ph[i].p_type) { 896 case Elf32_pt_load: 897 linux_elf_load_psection(&epp->ep_vmcmds, epp->ep_vp, 898 &ph[i], &addr, &size, &prot); 899 if ((error = linux_elf_set_segment(epp, addr, size, 900 prot)) != 0) 901 goto bad; 902 break; 903 904 case Elf32_pt_shlib: 905 DPRINTF(("No support for COFF libraries (yet)\n")); 906 error = ENOEXEC; 907 goto bad; 908 909 case Elf32_pt_interp: 910 if (pp->p_filesz >= sizeof(interp)) { 911 DPRINTF(("Interpreter path too long %d\n", 912 pp->p_filesz)); 913 goto bad; 914 } 915 if ((error = linux_elf_read_from(epp->ep_vp, pp->p_offset, p, 916 (caddr_t) interp, pp->p_filesz)) != 0) 917 goto bad; 918 break; 919 920 case Elf32_pt_dynamic: 921 case Elf32_pt_phdr: 922 case Elf32_pt_note: 923 break; 924 925 default: 926 /* 927 * Not fatal, we don't need to understand everything 928 * :-) 929 */ 930 DPRINTF(("Unsupported program header type %d\n", 931 pp->p_type)); 932 break; 933 } 934 } 935 936 /* 937 * Check if we found a dynamically linked binary and arrange to load 938 * it's interpreter 939 */ 940 if (interp[0]) { 941 struct elf_args *ap; 942 pos = ~0; 943 944 ap = (struct elf_args *) malloc(sizeof(struct elf_args), 945 M_TEMP, M_WAITOK); 946 if ((error = linux_elf_load_file(p, interp, &epp->ep_vmcmds, 947 &epp->ep_entry, ap, &pos)) != 0) { 948 free((char *) ap, M_TEMP); 949 goto bad; 950 } 951 /* Arrange to load the program headers. */ 952 pos = LINUX_ELF_ALIGN(pos + NBPG, NBPG); 953 DPRINTF(("Program header @0x%x\n", pos)); 954 ap->arg_phaddr = pos; 955 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, phsize, 956 pos, epp->ep_vp, eh->e_phoff, 957 VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE); 958 pos += phsize; 959 960 ap->arg_phentsize = eh->e_phentsize; 961 ap->arg_phnum = eh->e_phnum; 962 ap->arg_entry = eh->e_entry; 963 964 epp->ep_emul_arg = ap; 965 } else 966 epp->ep_entry = eh->e_entry; 967 968 DPRINTF(("taddr 0x%x tsize 0x%x daddr 0x%x dsize 0x%x\n", 969 epp->ep_taddr, epp->ep_tsize, epp->ep_daddr, epp->ep_dsize)); 970 971 free((char *) ph, M_TEMP); 972 973 DPRINTF(("Elf entry@ 0x%x\n", epp->ep_entry)); 974 epp->ep_vp->v_flag |= VTEXT; 975 976 epp->ep_emul = &emul_linux_elf; 977 978 return exec_aout_setup_stack(p, epp); 979 980bad: 981 free((char *) ph, M_TEMP); 982 kill_vmcmds(&epp->ep_vmcmds); 983 return ENOEXEC; 984} 985/* 986 * The Linux system call to load shared libraries, a.out version. The 987 * a.out shared libs are just files that are mapped onto a fixed 988 * address in the process' address space. The address is given in 989 * a_entry. Read in the header, set up some VM commands and run them. 990 * 991 * Yes, both text and data are mapped at once, so we're left with 992 * writeable text for the shared libs. The Linux crt0 seemed to break 993 * sometimes when data was mapped seperately. It munmapped a uselib() 994 * of ld.so by hand, which failed with shared text and data for ld.so 995 * Yuck. 996 * 997 * Because of the problem with ZMAGIC executables (text starts 998 * at 0x400 in the file, but needs to be mapped at 0), ZMAGIC 999 * shared libs are not handled very efficiently :-( 1000 */ 1001 1002int 1003linux_uselib(p, uap, retval) 1004 struct proc *p; 1005 struct linux_uselib_args /* { 1006 syscallarg(char *) path; 1007 } */ *uap; 1008 register_t *retval; 1009{ 1010 caddr_t sg; 1011 long bsize, dsize, tsize, taddr, baddr, daddr; 1012 struct nameidata ni; 1013 struct vnode *vp; 1014 struct exec hdr; 1015 struct exec_vmcmd_set vcset; 1016 int rem, i, magic, error; 1017 1018 sg = stackgap_init(); 1019 CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 1020 1021 NDINIT(&ni, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 1022 1023 if ((error = namei(&ni))) 1024 return error; 1025 1026 vp = ni.ni_vp; 1027 1028 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t) &hdr, LINUX_AOUT_HDR_SIZE, 1029 0, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, 1030 &rem, p))) { 1031 vrele(vp); 1032 return error; 1033 } 1034 1035 if (rem != 0) { 1036 vrele(vp); 1037 return ENOEXEC; 1038 } 1039 1040 if (LINUX_N_MACHTYPE(&hdr) != LINUX_MID_MACHINE) 1041 return ENOEXEC; 1042 1043 magic = LINUX_N_MAGIC(&hdr); 1044 taddr = hdr.a_entry & (~(NBPG - 1)); 1045 tsize = hdr.a_text; 1046 daddr = taddr + tsize; 1047 dsize = hdr.a_data + hdr.a_bss; 1048 1049 if ((hdr.a_text != 0 || hdr.a_data != 0) && vp->v_writecount != 0) { 1050 vrele(vp); 1051 return ETXTBSY; 1052 } 1053 vp->v_flag |= VTEXT; 1054 1055 vcset.evs_cnt = 0; 1056 vcset.evs_used = 0; 1057 1058 NEW_VMCMD(&vcset, 1059 magic == ZMAGIC ? vmcmd_map_readvn : vmcmd_map_pagedvn, 1060 hdr.a_text + hdr.a_data, taddr, 1061 vp, LINUX_N_TXTOFF(hdr, magic), 1062 VM_PROT_READ|VM_PROT_EXECUTE|VM_PROT_WRITE); 1063 1064 baddr = roundup(daddr + hdr.a_data, NBPG); 1065 bsize = daddr + dsize - baddr; 1066 if (bsize > 0) { 1067 NEW_VMCMD(&vcset, vmcmd_map_zero, bsize, baddr, 1068 NULLVP, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); 1069 } 1070 1071 for (i = 0; i < vcset.evs_used && !error; i++) { 1072 struct exec_vmcmd *vcp; 1073 1074 vcp = &vcset.evs_cmds[i]; 1075 error = (*vcp->ev_proc)(p, vcp); 1076 } 1077 1078 kill_vmcmds(&vcset); 1079 1080 vrele(vp); 1081 1082 return error; 1083} 1084 1085/* 1086 * Execve(2). Just check the alternate emulation path, and pass it on 1087 * to the NetBSD execve(). 1088 */ 1089int 1090linux_execve(p, uap, retval) 1091 struct proc *p; 1092 struct linux_execve_args /* { 1093 syscallarg(char *) path; 1094 syscallarg(char **) argv; 1095 syscallarg(char **) envp; 1096 } */ *uap; 1097 register_t *retval; 1098{ 1099 caddr_t sg; 1100 1101 sg = stackgap_init(); 1102 CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 1103 1104 return execve(p, uap, retval); 1105} 1106