1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1994-1996 Søren Schmidt 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 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/exec.h> 35 #include <sys/fcntl.h> 36 #include <sys/imgact.h> 37 #include <sys/imgact_aout.h> 38 #include <sys/imgact_elf.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/malloc.h> 42 #include <sys/module.h> 43 #include <sys/mutex.h> 44 #include <sys/proc.h> 45 #include <sys/signalvar.h> 46 #include <sys/syscallsubr.h> 47 #include <sys/sysctl.h> 48 #include <sys/sysent.h> 49 #include <sys/sysproto.h> 50 #include <sys/vnode.h> 51 #include <sys/eventhandler.h> 52 53 #include <vm/vm.h> 54 #include <vm/pmap.h> 55 #include <vm/vm_extern.h> 56 #include <vm/vm_map.h> 57 #include <vm/vm_object.h> 58 #include <vm/vm_page.h> 59 #include <vm/vm_param.h> 60 61 #include <machine/cpu.h> 62 #include <machine/cputypes.h> 63 #include <machine/md_var.h> 64 #include <machine/pcb.h> 65 #include <machine/trap.h> 66 67 #include <i386/linux/linux.h> 68 #include <i386/linux/linux_proto.h> 69 #include <compat/linux/linux_emul.h> 70 #include <compat/linux/linux_futex.h> 71 #include <compat/linux/linux_ioctl.h> 72 #include <compat/linux/linux_mib.h> 73 #include <compat/linux/linux_misc.h> 74 #include <compat/linux/linux_signal.h> 75 #include <compat/linux/linux_util.h> 76 #include <compat/linux/linux_vdso.h> 77 78 MODULE_VERSION(linux, 1); 79 80 #define LINUX_PS_STRINGS (LINUX_USRSTACK - sizeof(struct ps_strings)) 81 82 static int linux_szsigcode; 83 static vm_object_t linux_shared_page_obj; 84 static char *linux_shared_page_mapping; 85 extern char _binary_linux_locore_o_start; 86 extern char _binary_linux_locore_o_end; 87 88 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 89 90 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 91 92 static int linux_fixup(register_t **stack_base, 93 struct image_params *iparams); 94 static int linux_fixup_elf(register_t **stack_base, 95 struct image_params *iparams); 96 static void linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask); 97 static void linux_exec_setregs(struct thread *td, 98 struct image_params *imgp, u_long stack); 99 static register_t *linux_copyout_strings(struct image_params *imgp); 100 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel); 101 static void linux_vdso_install(void *param); 102 static void linux_vdso_deinstall(void *param); 103 104 static int linux_szplatform; 105 const char *linux_kplatform; 106 107 static eventhandler_tag linux_exit_tag; 108 static eventhandler_tag linux_exec_tag; 109 static eventhandler_tag linux_thread_dtor_tag; 110 111 #define LINUX_T_UNKNOWN 255 112 static int _bsd_to_linux_trapcode[] = { 113 LINUX_T_UNKNOWN, /* 0 */ 114 6, /* 1 T_PRIVINFLT */ 115 LINUX_T_UNKNOWN, /* 2 */ 116 3, /* 3 T_BPTFLT */ 117 LINUX_T_UNKNOWN, /* 4 */ 118 LINUX_T_UNKNOWN, /* 5 */ 119 16, /* 6 T_ARITHTRAP */ 120 254, /* 7 T_ASTFLT */ 121 LINUX_T_UNKNOWN, /* 8 */ 122 13, /* 9 T_PROTFLT */ 123 1, /* 10 T_TRCTRAP */ 124 LINUX_T_UNKNOWN, /* 11 */ 125 14, /* 12 T_PAGEFLT */ 126 LINUX_T_UNKNOWN, /* 13 */ 127 17, /* 14 T_ALIGNFLT */ 128 LINUX_T_UNKNOWN, /* 15 */ 129 LINUX_T_UNKNOWN, /* 16 */ 130 LINUX_T_UNKNOWN, /* 17 */ 131 0, /* 18 T_DIVIDE */ 132 2, /* 19 T_NMI */ 133 4, /* 20 T_OFLOW */ 134 5, /* 21 T_BOUND */ 135 7, /* 22 T_DNA */ 136 8, /* 23 T_DOUBLEFLT */ 137 9, /* 24 T_FPOPFLT */ 138 10, /* 25 T_TSSFLT */ 139 11, /* 26 T_SEGNPFLT */ 140 12, /* 27 T_STKFLT */ 141 18, /* 28 T_MCHK */ 142 19, /* 29 T_XMMFLT */ 143 15 /* 30 T_RESERVED */ 144 }; 145 #define bsd_to_linux_trapcode(code) \ 146 ((code)<nitems(_bsd_to_linux_trapcode)? \ 147 _bsd_to_linux_trapcode[(code)]: \ 148 LINUX_T_UNKNOWN) 149 150 LINUX_VDSO_SYM_INTPTR(linux_sigcode); 151 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 152 LINUX_VDSO_SYM_INTPTR(linux_vsyscall); 153 154 /* 155 * If FreeBSD & Linux have a difference of opinion about what a trap 156 * means, deal with it here. 157 * 158 * MPSAFE 159 */ 160 static int 161 linux_translate_traps(int signal, int trap_code) 162 { 163 if (signal != SIGBUS) 164 return (signal); 165 switch (trap_code) { 166 case T_PROTFLT: 167 case T_TSSFLT: 168 case T_DOUBLEFLT: 169 case T_PAGEFLT: 170 return (SIGSEGV); 171 default: 172 return (signal); 173 } 174 } 175 176 static int 177 linux_fixup(register_t **stack_base, struct image_params *imgp) 178 { 179 register_t *argv, *envp; 180 181 argv = *stack_base; 182 envp = *stack_base + (imgp->args->argc + 1); 183 (*stack_base)--; 184 suword(*stack_base, (intptr_t)(void *)envp); 185 (*stack_base)--; 186 suword(*stack_base, (intptr_t)(void *)argv); 187 (*stack_base)--; 188 suword(*stack_base, imgp->args->argc); 189 return (0); 190 } 191 192 static int 193 linux_fixup_elf(register_t **stack_base, struct image_params *imgp) 194 { 195 struct proc *p; 196 Elf32_Auxargs *args; 197 Elf32_Auxinfo *argarray, *pos; 198 Elf32_Addr *auxbase, *uplatform; 199 struct ps_strings *arginfo; 200 int error, issetugid; 201 202 KASSERT(curthread->td_proc == imgp->proc, 203 ("unsafe linux_fixup_elf(), should be curproc")); 204 205 p = imgp->proc; 206 issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0; 207 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 208 uplatform = (Elf32_Addr *)((caddr_t)arginfo - linux_szplatform); 209 args = (Elf32_Auxargs *)imgp->auxargs; 210 auxbase = *stack_base + imgp->args->argc + 1 + imgp->args->envc + 1; 211 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 212 M_WAITOK | M_ZERO); 213 214 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, 215 imgp->proc->p_sysent->sv_shared_page_base); 216 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux_vsyscall); 217 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 218 219 /* 220 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0, 221 * as it has appeared in the 2.4.0-rc7 first time. 222 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK), 223 * glibc falls back to the hard-coded CLK_TCK value when aux entry 224 * is not present. 225 * Also see linux_times() implementation. 226 */ 227 if (linux_kernver(curthread) >= LINUX_KERNVER_2004000) 228 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 229 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 230 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 231 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 232 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 233 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 234 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 235 AUXARGS_ENTRY(pos, AT_BASE, args->base); 236 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 237 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 238 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 239 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 240 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 241 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(uplatform)); 242 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary); 243 if (imgp->execpathp != 0) 244 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp); 245 if (args->execfd != -1) 246 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 247 AUXARGS_ENTRY(pos, AT_NULL, 0); 248 249 free(imgp->auxargs, M_TEMP); 250 imgp->auxargs = NULL; 251 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 252 253 error = copyout(argarray, auxbase, sizeof(*argarray) * LINUX_AT_COUNT); 254 free(argarray, M_TEMP); 255 if (error != 0) 256 return (error); 257 258 (*stack_base)--; 259 if (suword(*stack_base, (register_t)imgp->args->argc) == -1) 260 return (EFAULT); 261 return (0); 262 } 263 264 /* 265 * Copied from kern/kern_exec.c 266 */ 267 static register_t * 268 linux_copyout_strings(struct image_params *imgp) 269 { 270 int argc, envc; 271 char **vectp; 272 char *stringp, *destp; 273 register_t *stack_base; 274 struct ps_strings *arginfo; 275 char canary[LINUX_AT_RANDOM_LEN]; 276 size_t execpath_len; 277 struct proc *p; 278 279 /* Calculate string base and vector table pointers. */ 280 p = imgp->proc; 281 if (imgp->execpath != NULL && imgp->auxargs != NULL) 282 execpath_len = strlen(imgp->execpath) + 1; 283 else 284 execpath_len = 0; 285 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 286 destp = (caddr_t)arginfo - SPARE_USRSPACE - linux_szplatform - 287 roundup(sizeof(canary), sizeof(char *)) - 288 roundup(execpath_len, sizeof(char *)) - 289 roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *)); 290 291 /* Install LINUX_PLATFORM. */ 292 copyout(linux_kplatform, ((caddr_t)arginfo - linux_szplatform), 293 linux_szplatform); 294 295 if (execpath_len != 0) { 296 imgp->execpathp = (uintptr_t)arginfo - 297 linux_szplatform - execpath_len; 298 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len); 299 } 300 301 /* Prepare the canary for SSP. */ 302 arc4rand(canary, sizeof(canary), 0); 303 imgp->canary = (uintptr_t)arginfo - linux_szplatform - 304 roundup(execpath_len, sizeof(char *)) - 305 roundup(sizeof(canary), sizeof(char *)); 306 copyout(canary, (void *)imgp->canary, sizeof(canary)); 307 308 vectp = (char **)destp; 309 if (imgp->auxargs) { 310 /* 311 * Allocate room on the stack for the ELF auxargs 312 * array. It has LINUX_AT_COUNT entries. 313 */ 314 vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf32_Auxinfo), 315 sizeof(*vectp)); 316 } 317 318 /* 319 * Allocate room for the argv[] and env vectors including the 320 * terminating NULL pointers. 321 */ 322 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 323 324 /* vectp also becomes our initial stack base. */ 325 stack_base = (register_t *)vectp; 326 327 stringp = imgp->args->begin_argv; 328 argc = imgp->args->argc; 329 envc = imgp->args->envc; 330 331 /* Copy out strings - arguments and environment. */ 332 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace); 333 334 /* Fill in "ps_strings" struct for ps, w, etc. */ 335 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp); 336 suword(&arginfo->ps_nargvstr, argc); 337 338 /* Fill in argument portion of vector table. */ 339 for (; argc > 0; --argc) { 340 suword(vectp++, (long)(intptr_t)destp); 341 while (*stringp++ != 0) 342 destp++; 343 destp++; 344 } 345 346 /* A null vector table pointer separates the argp's from the envp's. */ 347 suword(vectp++, 0); 348 349 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp); 350 suword(&arginfo->ps_nenvstr, envc); 351 352 /* Fill in environment portion of vector table. */ 353 for (; envc > 0; --envc) { 354 suword(vectp++, (long)(intptr_t)destp); 355 while (*stringp++ != 0) 356 destp++; 357 destp++; 358 } 359 360 /* The end of the vector table is a null pointer. */ 361 suword(vectp, 0); 362 363 return (stack_base); 364 } 365 366 static void 367 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 368 { 369 struct thread *td = curthread; 370 struct proc *p = td->td_proc; 371 struct sigacts *psp; 372 struct trapframe *regs; 373 struct l_rt_sigframe *fp, frame; 374 int sig, code; 375 int oonstack; 376 377 sig = ksi->ksi_signo; 378 code = ksi->ksi_code; 379 PROC_LOCK_ASSERT(p, MA_OWNED); 380 psp = p->p_sigacts; 381 mtx_assert(&psp->ps_mtx, MA_OWNED); 382 regs = td->td_frame; 383 oonstack = sigonstack(regs->tf_esp); 384 385 /* Allocate space for the signal handler context. */ 386 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 387 SIGISMEMBER(psp->ps_sigonstack, sig)) { 388 fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 389 td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe)); 390 } else 391 fp = (struct l_rt_sigframe *)regs->tf_esp - 1; 392 mtx_unlock(&psp->ps_mtx); 393 394 /* Build the argument list for the signal handler. */ 395 sig = bsd_to_linux_signal(sig); 396 397 bzero(&frame, sizeof(frame)); 398 399 frame.sf_handler = catcher; 400 frame.sf_sig = sig; 401 frame.sf_siginfo = &fp->sf_si; 402 frame.sf_ucontext = &fp->sf_sc; 403 404 /* Fill in POSIX parts. */ 405 ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig); 406 407 /* Build the signal context to be used by sigreturn. */ 408 frame.sf_sc.uc_flags = 0; /* XXX ??? */ 409 frame.sf_sc.uc_link = NULL; /* XXX ??? */ 410 411 frame.sf_sc.uc_stack.ss_sp = td->td_sigstk.ss_sp; 412 frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 413 frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 414 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 415 PROC_UNLOCK(p); 416 417 bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask); 418 419 frame.sf_sc.uc_mcontext.sc_mask = frame.sf_sc.uc_sigmask.__mask; 420 frame.sf_sc.uc_mcontext.sc_gs = rgs(); 421 frame.sf_sc.uc_mcontext.sc_fs = regs->tf_fs; 422 frame.sf_sc.uc_mcontext.sc_es = regs->tf_es; 423 frame.sf_sc.uc_mcontext.sc_ds = regs->tf_ds; 424 frame.sf_sc.uc_mcontext.sc_edi = regs->tf_edi; 425 frame.sf_sc.uc_mcontext.sc_esi = regs->tf_esi; 426 frame.sf_sc.uc_mcontext.sc_ebp = regs->tf_ebp; 427 frame.sf_sc.uc_mcontext.sc_ebx = regs->tf_ebx; 428 frame.sf_sc.uc_mcontext.sc_esp = regs->tf_esp; 429 frame.sf_sc.uc_mcontext.sc_edx = regs->tf_edx; 430 frame.sf_sc.uc_mcontext.sc_ecx = regs->tf_ecx; 431 frame.sf_sc.uc_mcontext.sc_eax = regs->tf_eax; 432 frame.sf_sc.uc_mcontext.sc_eip = regs->tf_eip; 433 frame.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 434 frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_eflags; 435 frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_esp; 436 frame.sf_sc.uc_mcontext.sc_ss = regs->tf_ss; 437 frame.sf_sc.uc_mcontext.sc_err = regs->tf_err; 438 frame.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 439 frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 440 441 if (copyout(&frame, fp, sizeof(frame)) != 0) { 442 /* 443 * Process has trashed its stack; give it an illegal 444 * instruction to halt it in its tracks. 445 */ 446 PROC_LOCK(p); 447 sigexit(td, SIGILL); 448 } 449 450 /* Build context to run handler in. */ 451 regs->tf_esp = (int)fp; 452 regs->tf_eip = linux_rt_sigcode; 453 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D); 454 regs->tf_cs = _ucodesel; 455 regs->tf_ds = _udatasel; 456 regs->tf_es = _udatasel; 457 regs->tf_fs = _udatasel; 458 regs->tf_ss = _udatasel; 459 PROC_LOCK(p); 460 mtx_lock(&psp->ps_mtx); 461 } 462 463 464 /* 465 * Send an interrupt to process. 466 * 467 * Stack is set up to allow sigcode stored 468 * in u. to call routine, followed by kcall 469 * to sigreturn routine below. After sigreturn 470 * resets the signal mask, the stack, and the 471 * frame pointer, it returns to the user 472 * specified pc, psl. 473 */ 474 static void 475 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 476 { 477 struct thread *td = curthread; 478 struct proc *p = td->td_proc; 479 struct sigacts *psp; 480 struct trapframe *regs; 481 struct l_sigframe *fp, frame; 482 l_sigset_t lmask; 483 int sig, code; 484 int oonstack; 485 486 PROC_LOCK_ASSERT(p, MA_OWNED); 487 psp = p->p_sigacts; 488 sig = ksi->ksi_signo; 489 code = ksi->ksi_code; 490 mtx_assert(&psp->ps_mtx, MA_OWNED); 491 if (SIGISMEMBER(psp->ps_siginfo, sig)) { 492 /* Signal handler installed with SA_SIGINFO. */ 493 linux_rt_sendsig(catcher, ksi, mask); 494 return; 495 } 496 regs = td->td_frame; 497 oonstack = sigonstack(regs->tf_esp); 498 499 /* Allocate space for the signal handler context. */ 500 if ((td->td_pflags & TDP_ALTSTACK) && !oonstack && 501 SIGISMEMBER(psp->ps_sigonstack, sig)) { 502 fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 503 td->td_sigstk.ss_size - sizeof(struct l_sigframe)); 504 } else 505 fp = (struct l_sigframe *)regs->tf_esp - 1; 506 mtx_unlock(&psp->ps_mtx); 507 PROC_UNLOCK(p); 508 509 /* Build the argument list for the signal handler. */ 510 sig = bsd_to_linux_signal(sig); 511 512 bzero(&frame, sizeof(frame)); 513 514 frame.sf_handler = catcher; 515 frame.sf_sig = sig; 516 517 bsd_to_linux_sigset(mask, &lmask); 518 519 /* Build the signal context to be used by sigreturn. */ 520 frame.sf_sc.sc_mask = lmask.__mask; 521 frame.sf_sc.sc_gs = rgs(); 522 frame.sf_sc.sc_fs = regs->tf_fs; 523 frame.sf_sc.sc_es = regs->tf_es; 524 frame.sf_sc.sc_ds = regs->tf_ds; 525 frame.sf_sc.sc_edi = regs->tf_edi; 526 frame.sf_sc.sc_esi = regs->tf_esi; 527 frame.sf_sc.sc_ebp = regs->tf_ebp; 528 frame.sf_sc.sc_ebx = regs->tf_ebx; 529 frame.sf_sc.sc_esp = regs->tf_esp; 530 frame.sf_sc.sc_edx = regs->tf_edx; 531 frame.sf_sc.sc_ecx = regs->tf_ecx; 532 frame.sf_sc.sc_eax = regs->tf_eax; 533 frame.sf_sc.sc_eip = regs->tf_eip; 534 frame.sf_sc.sc_cs = regs->tf_cs; 535 frame.sf_sc.sc_eflags = regs->tf_eflags; 536 frame.sf_sc.sc_esp_at_signal = regs->tf_esp; 537 frame.sf_sc.sc_ss = regs->tf_ss; 538 frame.sf_sc.sc_err = regs->tf_err; 539 frame.sf_sc.sc_cr2 = (register_t)ksi->ksi_addr; 540 frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(ksi->ksi_trapno); 541 542 frame.sf_extramask[0] = lmask.__mask; 543 544 if (copyout(&frame, fp, sizeof(frame)) != 0) { 545 /* 546 * Process has trashed its stack; give it an illegal 547 * instruction to halt it in its tracks. 548 */ 549 PROC_LOCK(p); 550 sigexit(td, SIGILL); 551 } 552 553 /* Build context to run handler in. */ 554 regs->tf_esp = (int)fp; 555 regs->tf_eip = linux_sigcode; 556 regs->tf_eflags &= ~(PSL_T | PSL_VM | PSL_D); 557 regs->tf_cs = _ucodesel; 558 regs->tf_ds = _udatasel; 559 regs->tf_es = _udatasel; 560 regs->tf_fs = _udatasel; 561 regs->tf_ss = _udatasel; 562 PROC_LOCK(p); 563 mtx_lock(&psp->ps_mtx); 564 } 565 566 /* 567 * System call to cleanup state after a signal 568 * has been taken. Reset signal mask and 569 * stack state from context left by sendsig (above). 570 * Return to previous pc and psl as specified by 571 * context left by sendsig. Check carefully to 572 * make sure that the user has not modified the 573 * psl to gain improper privileges or to cause 574 * a machine fault. 575 */ 576 int 577 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args) 578 { 579 struct l_sigframe frame; 580 struct trapframe *regs; 581 l_sigset_t lmask; 582 sigset_t bmask; 583 int eflags; 584 ksiginfo_t ksi; 585 586 regs = td->td_frame; 587 588 /* 589 * The trampoline code hands us the sigframe. 590 * It is unsafe to keep track of it ourselves, in the event that a 591 * program jumps out of a signal handler. 592 */ 593 if (copyin(args->sfp, &frame, sizeof(frame)) != 0) 594 return (EFAULT); 595 596 /* Check for security violations. */ 597 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 598 eflags = frame.sf_sc.sc_eflags; 599 if (!EFLAGS_SECURE(eflags, regs->tf_eflags)) 600 return (EINVAL); 601 602 /* 603 * Don't allow users to load a valid privileged %cs. Let the 604 * hardware check for invalid selectors, excess privilege in 605 * other selectors, invalid %eip's and invalid %esp's. 606 */ 607 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 608 if (!CS_SECURE(frame.sf_sc.sc_cs)) { 609 ksiginfo_init_trap(&ksi); 610 ksi.ksi_signo = SIGBUS; 611 ksi.ksi_code = BUS_OBJERR; 612 ksi.ksi_trapno = T_PROTFLT; 613 ksi.ksi_addr = (void *)regs->tf_eip; 614 trapsignal(td, &ksi); 615 return (EINVAL); 616 } 617 618 lmask.__mask = frame.sf_sc.sc_mask; 619 linux_to_bsd_sigset(&lmask, &bmask); 620 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 621 622 /* Restore signal context. */ 623 /* %gs was restored by the trampoline. */ 624 regs->tf_fs = frame.sf_sc.sc_fs; 625 regs->tf_es = frame.sf_sc.sc_es; 626 regs->tf_ds = frame.sf_sc.sc_ds; 627 regs->tf_edi = frame.sf_sc.sc_edi; 628 regs->tf_esi = frame.sf_sc.sc_esi; 629 regs->tf_ebp = frame.sf_sc.sc_ebp; 630 regs->tf_ebx = frame.sf_sc.sc_ebx; 631 regs->tf_edx = frame.sf_sc.sc_edx; 632 regs->tf_ecx = frame.sf_sc.sc_ecx; 633 regs->tf_eax = frame.sf_sc.sc_eax; 634 regs->tf_eip = frame.sf_sc.sc_eip; 635 regs->tf_cs = frame.sf_sc.sc_cs; 636 regs->tf_eflags = eflags; 637 regs->tf_esp = frame.sf_sc.sc_esp_at_signal; 638 regs->tf_ss = frame.sf_sc.sc_ss; 639 640 return (EJUSTRETURN); 641 } 642 643 /* 644 * System call to cleanup state after a signal 645 * has been taken. Reset signal mask and 646 * stack state from context left by rt_sendsig (above). 647 * Return to previous pc and psl as specified by 648 * context left by sendsig. Check carefully to 649 * make sure that the user has not modified the 650 * psl to gain improper privileges or to cause 651 * a machine fault. 652 */ 653 int 654 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 655 { 656 struct l_ucontext uc; 657 struct l_sigcontext *context; 658 sigset_t bmask; 659 l_stack_t *lss; 660 stack_t ss; 661 struct trapframe *regs; 662 int eflags; 663 ksiginfo_t ksi; 664 665 regs = td->td_frame; 666 667 /* 668 * The trampoline code hands us the ucontext. 669 * It is unsafe to keep track of it ourselves, in the event that a 670 * program jumps out of a signal handler. 671 */ 672 if (copyin(args->ucp, &uc, sizeof(uc)) != 0) 673 return (EFAULT); 674 675 context = &uc.uc_mcontext; 676 677 /* Check for security violations. */ 678 #define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 679 eflags = context->sc_eflags; 680 if (!EFLAGS_SECURE(eflags, regs->tf_eflags)) 681 return (EINVAL); 682 683 /* 684 * Don't allow users to load a valid privileged %cs. Let the 685 * hardware check for invalid selectors, excess privilege in 686 * other selectors, invalid %eip's and invalid %esp's. 687 */ 688 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 689 if (!CS_SECURE(context->sc_cs)) { 690 ksiginfo_init_trap(&ksi); 691 ksi.ksi_signo = SIGBUS; 692 ksi.ksi_code = BUS_OBJERR; 693 ksi.ksi_trapno = T_PROTFLT; 694 ksi.ksi_addr = (void *)regs->tf_eip; 695 trapsignal(td, &ksi); 696 return (EINVAL); 697 } 698 699 linux_to_bsd_sigset(&uc.uc_sigmask, &bmask); 700 kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0); 701 702 /* Restore signal context. */ 703 /* %gs was restored by the trampoline. */ 704 regs->tf_fs = context->sc_fs; 705 regs->tf_es = context->sc_es; 706 regs->tf_ds = context->sc_ds; 707 regs->tf_edi = context->sc_edi; 708 regs->tf_esi = context->sc_esi; 709 regs->tf_ebp = context->sc_ebp; 710 regs->tf_ebx = context->sc_ebx; 711 regs->tf_edx = context->sc_edx; 712 regs->tf_ecx = context->sc_ecx; 713 regs->tf_eax = context->sc_eax; 714 regs->tf_eip = context->sc_eip; 715 regs->tf_cs = context->sc_cs; 716 regs->tf_eflags = eflags; 717 regs->tf_esp = context->sc_esp_at_signal; 718 regs->tf_ss = context->sc_ss; 719 720 /* Call sigaltstack & ignore results. */ 721 lss = &uc.uc_stack; 722 ss.ss_sp = lss->ss_sp; 723 ss.ss_size = lss->ss_size; 724 ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags); 725 726 (void)kern_sigaltstack(td, &ss, NULL); 727 728 return (EJUSTRETURN); 729 } 730 731 static int 732 linux_fetch_syscall_args(struct thread *td) 733 { 734 struct proc *p; 735 struct trapframe *frame; 736 struct syscall_args *sa; 737 738 p = td->td_proc; 739 frame = td->td_frame; 740 sa = &td->td_sa; 741 742 sa->code = frame->tf_eax; 743 sa->args[0] = frame->tf_ebx; 744 sa->args[1] = frame->tf_ecx; 745 sa->args[2] = frame->tf_edx; 746 sa->args[3] = frame->tf_esi; 747 sa->args[4] = frame->tf_edi; 748 sa->args[5] = frame->tf_ebp; /* Unconfirmed */ 749 750 if (sa->code >= p->p_sysent->sv_size) 751 /* nosys */ 752 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 753 else 754 sa->callp = &p->p_sysent->sv_table[sa->code]; 755 sa->narg = sa->callp->sy_narg; 756 757 td->td_retval[0] = 0; 758 td->td_retval[1] = frame->tf_edx; 759 760 return (0); 761 } 762 763 /* 764 * exec_setregs may initialize some registers differently than Linux 765 * does, thus potentially confusing Linux binaries. If necessary, we 766 * override the exec_setregs default(s) here. 767 */ 768 static void 769 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack) 770 { 771 struct pcb *pcb = td->td_pcb; 772 773 exec_setregs(td, imgp, stack); 774 775 /* Linux sets %gs to 0, we default to _udatasel. */ 776 pcb->pcb_gs = 0; 777 load_gs(0); 778 779 pcb->pcb_initial_npxcw = __LINUX_NPXCW__; 780 } 781 782 static void 783 linux_get_machine(const char **dst) 784 { 785 786 switch (cpu_class) { 787 case CPUCLASS_686: 788 *dst = "i686"; 789 break; 790 case CPUCLASS_586: 791 *dst = "i586"; 792 break; 793 case CPUCLASS_486: 794 *dst = "i486"; 795 break; 796 default: 797 *dst = "i386"; 798 } 799 } 800 801 struct sysentvec linux_sysvec = { 802 .sv_size = LINUX_SYS_MAXSYSCALL, 803 .sv_table = linux_sysent, 804 .sv_errsize = ELAST + 1, 805 .sv_errtbl = linux_errtbl, 806 .sv_transtrap = linux_translate_traps, 807 .sv_fixup = linux_fixup, 808 .sv_sendsig = linux_sendsig, 809 .sv_sigcode = &_binary_linux_locore_o_start, 810 .sv_szsigcode = &linux_szsigcode, 811 .sv_name = "Linux a.out", 812 .sv_coredump = NULL, 813 .sv_imgact_try = linux_exec_imgact_try, 814 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 815 .sv_minuser = VM_MIN_ADDRESS, 816 .sv_maxuser = VM_MAXUSER_ADDRESS, 817 .sv_usrstack = LINUX_USRSTACK, 818 .sv_psstrings = PS_STRINGS, 819 .sv_stackprot = VM_PROT_ALL, 820 .sv_copyout_strings = exec_copyout_strings, 821 .sv_setregs = linux_exec_setregs, 822 .sv_fixlimit = NULL, 823 .sv_maxssiz = NULL, 824 .sv_flags = SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32, 825 .sv_set_syscall_retval = cpu_set_syscall_retval, 826 .sv_fetch_syscall_args = linux_fetch_syscall_args, 827 .sv_syscallnames = NULL, 828 .sv_shared_page_base = LINUX_SHAREDPAGE, 829 .sv_shared_page_len = PAGE_SIZE, 830 .sv_schedtail = linux_schedtail, 831 .sv_thread_detach = linux_thread_detach, 832 .sv_trap = NULL, 833 }; 834 INIT_SYSENTVEC(aout_sysvec, &linux_sysvec); 835 836 struct sysentvec elf_linux_sysvec = { 837 .sv_size = LINUX_SYS_MAXSYSCALL, 838 .sv_table = linux_sysent, 839 .sv_errsize = ELAST + 1, 840 .sv_errtbl = linux_errtbl, 841 .sv_transtrap = linux_translate_traps, 842 .sv_fixup = linux_fixup_elf, 843 .sv_sendsig = linux_sendsig, 844 .sv_sigcode = &_binary_linux_locore_o_start, 845 .sv_szsigcode = &linux_szsigcode, 846 .sv_name = "Linux ELF", 847 .sv_coredump = elf32_coredump, 848 .sv_imgact_try = linux_exec_imgact_try, 849 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 850 .sv_minuser = VM_MIN_ADDRESS, 851 .sv_maxuser = VM_MAXUSER_ADDRESS, 852 .sv_usrstack = LINUX_USRSTACK, 853 .sv_psstrings = LINUX_PS_STRINGS, 854 .sv_stackprot = VM_PROT_ALL, 855 .sv_copyout_strings = linux_copyout_strings, 856 .sv_setregs = linux_exec_setregs, 857 .sv_fixlimit = NULL, 858 .sv_maxssiz = NULL, 859 .sv_flags = SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP, 860 .sv_set_syscall_retval = cpu_set_syscall_retval, 861 .sv_fetch_syscall_args = linux_fetch_syscall_args, 862 .sv_syscallnames = NULL, 863 .sv_shared_page_base = LINUX_SHAREDPAGE, 864 .sv_shared_page_len = PAGE_SIZE, 865 .sv_schedtail = linux_schedtail, 866 .sv_thread_detach = linux_thread_detach, 867 .sv_trap = NULL, 868 }; 869 870 static void 871 linux_vdso_install(void *param) 872 { 873 874 linux_szsigcode = (&_binary_linux_locore_o_end - 875 &_binary_linux_locore_o_start); 876 877 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len) 878 panic("Linux invalid vdso size\n"); 879 880 __elfN(linux_vdso_fixup)(&elf_linux_sysvec); 881 882 linux_shared_page_obj = __elfN(linux_shared_page_init) 883 (&linux_shared_page_mapping); 884 885 __elfN(linux_vdso_reloc)(&elf_linux_sysvec); 886 887 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping, 888 linux_szsigcode); 889 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj; 890 } 891 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY, 892 linux_vdso_install, NULL); 893 894 static void 895 linux_vdso_deinstall(void *param) 896 { 897 898 __elfN(linux_shared_page_fini)(linux_shared_page_obj); 899 } 900 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 901 linux_vdso_deinstall, NULL); 902 903 static char GNU_ABI_VENDOR[] = "GNU"; 904 static int GNULINUX_ABI_DESC = 0; 905 906 static bool 907 linux_trans_osrel(const Elf_Note *note, int32_t *osrel) 908 { 909 const Elf32_Word *desc; 910 uintptr_t p; 911 912 p = (uintptr_t)(note + 1); 913 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 914 915 desc = (const Elf32_Word *)p; 916 if (desc[0] != GNULINUX_ABI_DESC) 917 return (false); 918 919 /* 920 * For Linux we encode osrel using the Linux convention of 921 * (version << 16) | (major << 8) | (minor) 922 * See macro in linux_mib.h 923 */ 924 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]); 925 926 return (true); 927 } 928 929 static Elf_Brandnote linux_brandnote = { 930 .hdr.n_namesz = sizeof(GNU_ABI_VENDOR), 931 .hdr.n_descsz = 16, /* XXX at least 16 */ 932 .hdr.n_type = 1, 933 .vendor = GNU_ABI_VENDOR, 934 .flags = BN_TRANSLATE_OSREL, 935 .trans_osrel = linux_trans_osrel 936 }; 937 938 static Elf32_Brandinfo linux_brand = { 939 .brand = ELFOSABI_LINUX, 940 .machine = EM_386, 941 .compat_3_brand = "Linux", 942 .emul_path = "/compat/linux", 943 .interp_path = "/lib/ld-linux.so.1", 944 .sysvec = &elf_linux_sysvec, 945 .interp_newpath = NULL, 946 .brand_note = &linux_brandnote, 947 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 948 }; 949 950 static Elf32_Brandinfo linux_glibc2brand = { 951 .brand = ELFOSABI_LINUX, 952 .machine = EM_386, 953 .compat_3_brand = "Linux", 954 .emul_path = "/compat/linux", 955 .interp_path = "/lib/ld-linux.so.2", 956 .sysvec = &elf_linux_sysvec, 957 .interp_newpath = NULL, 958 .brand_note = &linux_brandnote, 959 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 960 }; 961 962 static Elf32_Brandinfo linux_muslbrand = { 963 .brand = ELFOSABI_LINUX, 964 .machine = EM_386, 965 .compat_3_brand = "Linux", 966 .emul_path = "/compat/linux", 967 .interp_path = "/lib/ld-musl-i386.so.1", 968 .sysvec = &elf_linux_sysvec, 969 .interp_newpath = NULL, 970 .brand_note = &linux_brandnote, 971 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 972 }; 973 974 Elf32_Brandinfo *linux_brandlist[] = { 975 &linux_brand, 976 &linux_glibc2brand, 977 &linux_muslbrand, 978 NULL 979 }; 980 981 static int 982 linux_elf_modevent(module_t mod, int type, void *data) 983 { 984 Elf32_Brandinfo **brandinfo; 985 int error; 986 struct linux_ioctl_handler **lihp; 987 988 error = 0; 989 990 switch(type) { 991 case MOD_LOAD: 992 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 993 ++brandinfo) 994 if (elf32_insert_brand_entry(*brandinfo) < 0) 995 error = EINVAL; 996 if (error == 0) { 997 SET_FOREACH(lihp, linux_ioctl_handler_set) 998 linux_ioctl_register_handler(*lihp); 999 LIST_INIT(&futex_list); 1000 mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF); 1001 linux_exit_tag = EVENTHANDLER_REGISTER(process_exit, linux_proc_exit, 1002 NULL, 1000); 1003 linux_exec_tag = EVENTHANDLER_REGISTER(process_exec, linux_proc_exec, 1004 NULL, 1000); 1005 linux_thread_dtor_tag = EVENTHANDLER_REGISTER(thread_dtor, 1006 linux_thread_dtor, NULL, EVENTHANDLER_PRI_ANY); 1007 linux_get_machine(&linux_kplatform); 1008 linux_szplatform = roundup(strlen(linux_kplatform) + 1, 1009 sizeof(char *)); 1010 linux_osd_jail_register(); 1011 stclohz = (stathz ? stathz : hz); 1012 if (bootverbose) 1013 printf("Linux ELF exec handler installed\n"); 1014 } else 1015 printf("cannot insert Linux ELF brand handler\n"); 1016 break; 1017 case MOD_UNLOAD: 1018 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1019 ++brandinfo) 1020 if (elf32_brand_inuse(*brandinfo)) 1021 error = EBUSY; 1022 if (error == 0) { 1023 for (brandinfo = &linux_brandlist[0]; 1024 *brandinfo != NULL; ++brandinfo) 1025 if (elf32_remove_brand_entry(*brandinfo) < 0) 1026 error = EINVAL; 1027 } 1028 if (error == 0) { 1029 SET_FOREACH(lihp, linux_ioctl_handler_set) 1030 linux_ioctl_unregister_handler(*lihp); 1031 mtx_destroy(&futex_mtx); 1032 EVENTHANDLER_DEREGISTER(process_exit, linux_exit_tag); 1033 EVENTHANDLER_DEREGISTER(process_exec, linux_exec_tag); 1034 EVENTHANDLER_DEREGISTER(thread_dtor, linux_thread_dtor_tag); 1035 linux_osd_jail_deregister(); 1036 if (bootverbose) 1037 printf("Linux ELF exec handler removed\n"); 1038 } else 1039 printf("Could not deinstall ELF interpreter entry\n"); 1040 break; 1041 default: 1042 return (EOPNOTSUPP); 1043 } 1044 return (error); 1045 } 1046 1047 static moduledata_t linux_elf_mod = { 1048 "linuxelf", 1049 linux_elf_modevent, 1050 0 1051 }; 1052 1053 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1054 FEATURE(linux, "Linux 32bit support"); 1055