1 /*- 2 * Copyright (c) 2013 Dmitry Chagin 3 * Copyright (c) 2004 Tim J. Robbins 4 * Copyright (c) 2003 Peter Wemm 5 * Copyright (c) 2002 Doug Rabson 6 * Copyright (c) 1998-1999 Andrew Gallatin 7 * Copyright (c) 1994-1996 Søren Schmidt 8 * All rights reserved. 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 * in this position and unchanged. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. 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 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_compat.h" 38 39 #define __ELF_WORD_SIZE 64 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/exec.h> 44 #include <sys/fcntl.h> 45 #include <sys/imgact.h> 46 #include <sys/imgact_elf.h> 47 #include <sys/kernel.h> 48 #include <sys/ktr.h> 49 #include <sys/lock.h> 50 #include <sys/malloc.h> 51 #include <sys/module.h> 52 #include <sys/mutex.h> 53 #include <sys/proc.h> 54 #include <sys/resourcevar.h> 55 #include <sys/signalvar.h> 56 #include <sys/syscallsubr.h> 57 #include <sys/sysctl.h> 58 #include <sys/sysent.h> 59 #include <sys/sysproto.h> 60 #include <sys/vnode.h> 61 #include <sys/eventhandler.h> 62 63 #include <vm/vm.h> 64 #include <vm/pmap.h> 65 #include <vm/vm_extern.h> 66 #include <vm/vm_map.h> 67 #include <vm/vm_object.h> 68 #include <vm/vm_page.h> 69 #include <vm/vm_param.h> 70 71 #include <machine/cpu.h> 72 #include <machine/md_var.h> 73 #include <machine/pcb.h> 74 #include <machine/specialreg.h> 75 #include <machine/trap.h> 76 77 #include <amd64/linux/linux.h> 78 #include <amd64/linux/linux_proto.h> 79 #include <compat/linux/linux_emul.h> 80 #include <compat/linux/linux_futex.h> 81 #include <compat/linux/linux_ioctl.h> 82 #include <compat/linux/linux_mib.h> 83 #include <compat/linux/linux_misc.h> 84 #include <compat/linux/linux_signal.h> 85 #include <compat/linux/linux_sysproto.h> 86 #include <compat/linux/linux_util.h> 87 #include <compat/linux/linux_vdso.h> 88 89 MODULE_VERSION(linux64, 1); 90 91 #if BYTE_ORDER == LITTLE_ENDIAN 92 #define SHELLMAGIC 0x2123 /* #! */ 93 #else 94 #define SHELLMAGIC 0x2321 95 #endif 96 97 #if defined(DEBUG) 98 SYSCTL_PROC(_compat_linux, OID_AUTO, debug, 99 CTLTYPE_STRING | CTLFLAG_RW, 100 0, 0, linux_sysctl_debug, "A", 101 "Linux 64 debugging control"); 102 #endif 103 104 /* 105 * Allow the sendsig functions to use the ldebug() facility even though they 106 * are not syscalls themselves. Map them to syscall 0. This is slightly less 107 * bogus than using ldebug(sigreturn). 108 */ 109 #define LINUX_SYS_linux_rt_sendsig 0 110 111 const char *linux_kplatform; 112 static int linux_szsigcode; 113 static vm_object_t linux_shared_page_obj; 114 static char *linux_shared_page_mapping; 115 extern char _binary_linux_locore_o_start; 116 extern char _binary_linux_locore_o_end; 117 118 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 119 120 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 121 122 static register_t * linux_copyout_strings(struct image_params *imgp); 123 static int linux_fixup_elf(register_t **stack_base, 124 struct image_params *iparams); 125 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel); 126 static void linux_vdso_install(void *param); 127 static void linux_vdso_deinstall(void *param); 128 static void linux_set_syscall_retval(struct thread *td, int error); 129 static int linux_fetch_syscall_args(struct thread *td); 130 static int linux_exec_imgact_try(struct image_params *iparams); 131 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 132 u_long stack); 133 static int linux_vsyscall(struct thread *td); 134 135 #define LINUX_T_UNKNOWN 255 136 static int _bsd_to_linux_trapcode[] = { 137 LINUX_T_UNKNOWN, /* 0 */ 138 6, /* 1 T_PRIVINFLT */ 139 LINUX_T_UNKNOWN, /* 2 */ 140 3, /* 3 T_BPTFLT */ 141 LINUX_T_UNKNOWN, /* 4 */ 142 LINUX_T_UNKNOWN, /* 5 */ 143 16, /* 6 T_ARITHTRAP */ 144 254, /* 7 T_ASTFLT */ 145 LINUX_T_UNKNOWN, /* 8 */ 146 13, /* 9 T_PROTFLT */ 147 1, /* 10 T_TRCTRAP */ 148 LINUX_T_UNKNOWN, /* 11 */ 149 14, /* 12 T_PAGEFLT */ 150 LINUX_T_UNKNOWN, /* 13 */ 151 17, /* 14 T_ALIGNFLT */ 152 LINUX_T_UNKNOWN, /* 15 */ 153 LINUX_T_UNKNOWN, /* 16 */ 154 LINUX_T_UNKNOWN, /* 17 */ 155 0, /* 18 T_DIVIDE */ 156 2, /* 19 T_NMI */ 157 4, /* 20 T_OFLOW */ 158 5, /* 21 T_BOUND */ 159 7, /* 22 T_DNA */ 160 8, /* 23 T_DOUBLEFLT */ 161 9, /* 24 T_FPOPFLT */ 162 10, /* 25 T_TSSFLT */ 163 11, /* 26 T_SEGNPFLT */ 164 12, /* 27 T_STKFLT */ 165 18, /* 28 T_MCHK */ 166 19, /* 29 T_XMMFLT */ 167 15 /* 30 T_RESERVED */ 168 }; 169 #define bsd_to_linux_trapcode(code) \ 170 ((code)<nitems(_bsd_to_linux_trapcode)? \ 171 _bsd_to_linux_trapcode[(code)]: \ 172 LINUX_T_UNKNOWN) 173 174 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 175 LINUX_VDSO_SYM_CHAR(linux_platform); 176 177 /* 178 * If FreeBSD & Linux have a difference of opinion about what a trap 179 * means, deal with it here. 180 * 181 * MPSAFE 182 */ 183 static int 184 linux_translate_traps(int signal, int trap_code) 185 { 186 187 if (signal != SIGBUS) 188 return (signal); 189 switch (trap_code) { 190 case T_PROTFLT: 191 case T_TSSFLT: 192 case T_DOUBLEFLT: 193 case T_PAGEFLT: 194 return (SIGSEGV); 195 default: 196 return (signal); 197 } 198 } 199 200 static int 201 linux_fetch_syscall_args(struct thread *td) 202 { 203 struct proc *p; 204 struct trapframe *frame; 205 struct syscall_args *sa; 206 207 p = td->td_proc; 208 frame = td->td_frame; 209 sa = &td->td_sa; 210 211 sa->args[0] = frame->tf_rdi; 212 sa->args[1] = frame->tf_rsi; 213 sa->args[2] = frame->tf_rdx; 214 sa->args[3] = frame->tf_rcx; 215 sa->args[4] = frame->tf_r8; 216 sa->args[5] = frame->tf_r9; 217 sa->code = frame->tf_rax; 218 219 if (sa->code >= p->p_sysent->sv_size) 220 /* nosys */ 221 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 222 else 223 sa->callp = &p->p_sysent->sv_table[sa->code]; 224 sa->narg = sa->callp->sy_narg; 225 226 td->td_retval[0] = 0; 227 return (0); 228 } 229 230 static void 231 linux_set_syscall_retval(struct thread *td, int error) 232 { 233 struct trapframe *frame = td->td_frame; 234 235 /* 236 * On Linux only %rcx and %r11 values are not preserved across 237 * the syscall. So, do not clobber %rdx and %r10. 238 */ 239 td->td_retval[1] = frame->tf_rdx; 240 frame->tf_r10 = frame->tf_rcx; 241 242 cpu_set_syscall_retval(td, error); 243 244 /* Restore all registers. */ 245 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 246 } 247 248 static int 249 linux_fixup_elf(register_t **stack_base, struct image_params *imgp) 250 { 251 Elf_Auxargs *args; 252 Elf_Addr *base; 253 Elf_Addr *pos; 254 struct ps_strings *arginfo; 255 struct proc *p; 256 int issetugid; 257 258 p = imgp->proc; 259 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 260 261 KASSERT(curthread->td_proc == imgp->proc, 262 ("unsafe linux_fixup_elf(), should be curproc")); 263 base = (Elf64_Addr *)*stack_base; 264 args = (Elf64_Auxargs *)imgp->auxargs; 265 pos = base + (imgp->args->argc + imgp->args->envc + 2); 266 267 issetugid = p->p_flag & P_SUGID ? 1 : 0; 268 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, 269 imgp->proc->p_sysent->sv_shared_page_base); 270 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 271 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 272 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 273 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 274 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 275 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 276 AUXARGS_ENTRY(pos, AT_BASE, args->base); 277 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 278 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 279 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 280 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 281 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 282 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 283 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 284 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 285 AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, imgp->canary); 286 if (imgp->execpathp != 0) 287 AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, imgp->execpathp); 288 if (args->execfd != -1) 289 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 290 AUXARGS_ENTRY(pos, AT_NULL, 0); 291 free(imgp->auxargs, M_TEMP); 292 imgp->auxargs = NULL; 293 294 base--; 295 suword(base, (uint64_t)imgp->args->argc); 296 297 *stack_base = (register_t *)base; 298 return (0); 299 } 300 301 /* 302 * Copy strings out to the new process address space, constructing new arg 303 * and env vector tables. Return a pointer to the base so that it can be used 304 * as the initial stack pointer. 305 */ 306 static register_t * 307 linux_copyout_strings(struct image_params *imgp) 308 { 309 int argc, envc; 310 char **vectp; 311 char *stringp, *destp; 312 register_t *stack_base; 313 struct ps_strings *arginfo; 314 char canary[LINUX_AT_RANDOM_LEN]; 315 size_t execpath_len; 316 struct proc *p; 317 318 /* Calculate string base and vector table pointers. */ 319 if (imgp->execpath != NULL && imgp->auxargs != NULL) 320 execpath_len = strlen(imgp->execpath) + 1; 321 else 322 execpath_len = 0; 323 324 p = imgp->proc; 325 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 326 destp = (caddr_t)arginfo - SPARE_USRSPACE - 327 roundup(sizeof(canary), sizeof(char *)) - 328 roundup(execpath_len, sizeof(char *)) - 329 roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *)); 330 331 if (execpath_len != 0) { 332 imgp->execpathp = (uintptr_t)arginfo - execpath_len; 333 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len); 334 } 335 336 /* Prepare the canary for SSP. */ 337 arc4rand(canary, sizeof(canary), 0); 338 imgp->canary = (uintptr_t)arginfo - 339 roundup(execpath_len, sizeof(char *)) - 340 roundup(sizeof(canary), sizeof(char *)); 341 copyout(canary, (void *)imgp->canary, sizeof(canary)); 342 343 /* If we have a valid auxargs ptr, prepare some room on the stack. */ 344 if (imgp->auxargs) { 345 /* 346 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for 347 * lower compatibility. 348 */ 349 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size : 350 (LINUX_AT_COUNT * 2); 351 352 /* 353 * The '+ 2' is for the null pointers at the end of each of 354 * the arg and env vector sets,and imgp->auxarg_size is room 355 * for argument of Runtime loader. 356 */ 357 vectp = (char **)(destp - (imgp->args->argc + 358 imgp->args->envc + 2 + imgp->auxarg_size) * sizeof(char *)); 359 360 } else { 361 /* 362 * The '+ 2' is for the null pointers at the end of each of 363 * the arg and env vector sets 364 */ 365 vectp = (char **)(destp - (imgp->args->argc + 366 imgp->args->envc + 2) * sizeof(char *)); 367 } 368 369 /* vectp also becomes our initial stack base. */ 370 stack_base = (register_t *)vectp; 371 372 stringp = imgp->args->begin_argv; 373 argc = imgp->args->argc; 374 envc = imgp->args->envc; 375 376 /* Copy out strings - arguments and environment. */ 377 copyout(stringp, destp, ARG_MAX - imgp->args->stringspace); 378 379 /* Fill in "ps_strings" struct for ps, w, etc. */ 380 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp); 381 suword(&arginfo->ps_nargvstr, argc); 382 383 /* Fill in argument portion of vector table. */ 384 for (; argc > 0; --argc) { 385 suword(vectp++, (long)(intptr_t)destp); 386 while (*stringp++ != 0) 387 destp++; 388 destp++; 389 } 390 391 /* A null vector table pointer separates the argp's from the envp's. */ 392 suword(vectp++, 0); 393 394 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp); 395 suword(&arginfo->ps_nenvstr, envc); 396 397 /* Fill in environment portion of vector table. */ 398 for (; envc > 0; --envc) { 399 suword(vectp++, (long)(intptr_t)destp); 400 while (*stringp++ != 0) 401 destp++; 402 destp++; 403 } 404 405 /* The end of the vector table is a null pointer. */ 406 suword(vectp, 0); 407 return (stack_base); 408 } 409 410 /* 411 * Reset registers to default values on exec. 412 */ 413 static void 414 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack) 415 { 416 struct trapframe *regs = td->td_frame; 417 struct pcb *pcb = td->td_pcb; 418 419 if (td->td_proc->p_md.md_ldt != NULL) 420 user_ldt_free(td); 421 422 pcb->pcb_fsbase = 0; 423 pcb->pcb_gsbase = 0; 424 clear_pcb_flags(pcb, PCB_32BIT); 425 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 426 set_pcb_flags(pcb, PCB_FULL_IRET); 427 428 bzero((char *)regs, sizeof(struct trapframe)); 429 regs->tf_rip = imgp->entry_addr; 430 regs->tf_rsp = stack; 431 regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T); 432 regs->tf_ss = _udatasel; 433 regs->tf_cs = _ucodesel; 434 regs->tf_ds = _udatasel; 435 regs->tf_es = _udatasel; 436 regs->tf_fs = _ufssel; 437 regs->tf_gs = _ugssel; 438 regs->tf_flags = TF_HASSEGS; 439 440 /* 441 * Reset the hardware debug registers if they were in use. 442 * They won't have any meaning for the newly exec'd process. 443 */ 444 if (pcb->pcb_flags & PCB_DBREGS) { 445 pcb->pcb_dr0 = 0; 446 pcb->pcb_dr1 = 0; 447 pcb->pcb_dr2 = 0; 448 pcb->pcb_dr3 = 0; 449 pcb->pcb_dr6 = 0; 450 pcb->pcb_dr7 = 0; 451 if (pcb == curpcb) { 452 /* 453 * Clear the debug registers on the running 454 * CPU, otherwise they will end up affecting 455 * the next process we switch to. 456 */ 457 reset_dbregs(); 458 } 459 clear_pcb_flags(pcb, PCB_DBREGS); 460 } 461 462 /* 463 * Drop the FP state if we hold it, so that the process gets a 464 * clean FP state if it uses the FPU again. 465 */ 466 fpstate_drop(td); 467 } 468 469 /* 470 * Copied from amd64/amd64/machdep.c 471 * 472 * XXX fpu state need? don't think so 473 */ 474 int 475 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 476 { 477 struct proc *p; 478 struct l_ucontext uc; 479 struct l_sigcontext *context; 480 struct trapframe *regs; 481 unsigned long rflags; 482 int error; 483 ksiginfo_t ksi; 484 485 regs = td->td_frame; 486 error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc)); 487 if (error != 0) 488 return (error); 489 490 p = td->td_proc; 491 context = &uc.uc_mcontext; 492 rflags = context->sc_rflags; 493 494 /* 495 * Don't allow users to change privileged or reserved flags. 496 */ 497 /* 498 * XXX do allow users to change the privileged flag PSL_RF. 499 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 500 * should sometimes set it there too. tf_rflags is kept in 501 * the signal context during signal handling and there is no 502 * other place to remember it, so the PSL_RF bit may be 503 * corrupted by the signal handler without us knowing. 504 * Corruption of the PSL_RF bit at worst causes one more or 505 * one less debugger trap, so allowing it is fairly harmless. 506 */ 507 508 #define RFLAG_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 509 if (!RFLAG_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 510 printf("linux_rt_sigreturn: rflags = 0x%lx\n", rflags); 511 return (EINVAL); 512 } 513 514 /* 515 * Don't allow users to load a valid privileged %cs. Let the 516 * hardware check for invalid selectors, excess privilege in 517 * other selectors, invalid %eip's and invalid %esp's. 518 */ 519 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 520 if (!CS_SECURE(context->sc_cs)) { 521 printf("linux_rt_sigreturn: cs = 0x%x\n", context->sc_cs); 522 ksiginfo_init_trap(&ksi); 523 ksi.ksi_signo = SIGBUS; 524 ksi.ksi_code = BUS_OBJERR; 525 ksi.ksi_trapno = T_PROTFLT; 526 ksi.ksi_addr = (void *)regs->tf_rip; 527 trapsignal(td, &ksi); 528 return (EINVAL); 529 } 530 531 PROC_LOCK(p); 532 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask); 533 SIG_CANTMASK(td->td_sigmask); 534 signotify(td); 535 PROC_UNLOCK(p); 536 537 regs->tf_rdi = context->sc_rdi; 538 regs->tf_rsi = context->sc_rsi; 539 regs->tf_rdx = context->sc_rdx; 540 regs->tf_rbp = context->sc_rbp; 541 regs->tf_rbx = context->sc_rbx; 542 regs->tf_rcx = context->sc_rcx; 543 regs->tf_rax = context->sc_rax; 544 regs->tf_rip = context->sc_rip; 545 regs->tf_rsp = context->sc_rsp; 546 regs->tf_r8 = context->sc_r8; 547 regs->tf_r9 = context->sc_r9; 548 regs->tf_r10 = context->sc_r10; 549 regs->tf_r11 = context->sc_r11; 550 regs->tf_r12 = context->sc_r12; 551 regs->tf_r13 = context->sc_r13; 552 regs->tf_r14 = context->sc_r14; 553 regs->tf_r15 = context->sc_r15; 554 regs->tf_cs = context->sc_cs; 555 regs->tf_err = context->sc_err; 556 regs->tf_rflags = rflags; 557 558 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 559 return (EJUSTRETURN); 560 } 561 562 /* 563 * copied from amd64/amd64/machdep.c 564 * 565 * Send an interrupt to process. 566 */ 567 static void 568 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 569 { 570 struct l_rt_sigframe sf, *sfp; 571 struct proc *p; 572 struct thread *td; 573 struct sigacts *psp; 574 caddr_t sp; 575 struct trapframe *regs; 576 int sig, code; 577 int oonstack; 578 579 td = curthread; 580 p = td->td_proc; 581 PROC_LOCK_ASSERT(p, MA_OWNED); 582 sig = ksi->ksi_signo; 583 psp = p->p_sigacts; 584 code = ksi->ksi_code; 585 mtx_assert(&psp->ps_mtx, MA_OWNED); 586 regs = td->td_frame; 587 oonstack = sigonstack(regs->tf_rsp); 588 589 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 590 catcher, sig, mask, code); 591 592 /* Allocate space for the signal handler context. */ 593 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 594 SIGISMEMBER(psp->ps_sigonstack, sig)) { 595 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size - 596 sizeof(struct l_rt_sigframe); 597 } else 598 sp = (caddr_t)regs->tf_rsp - sizeof(struct l_rt_sigframe) - 128; 599 /* Align to 16 bytes. */ 600 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 601 mtx_unlock(&psp->ps_mtx); 602 603 /* Translate the signal. */ 604 sig = bsd_to_linux_signal(sig); 605 606 /* Save user context. */ 607 bzero(&sf, sizeof(sf)); 608 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask); 609 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask); 610 611 sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 612 sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 613 sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 614 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 615 PROC_UNLOCK(p); 616 617 sf.sf_sc.uc_mcontext.sc_rdi = regs->tf_rdi; 618 sf.sf_sc.uc_mcontext.sc_rsi = regs->tf_rsi; 619 sf.sf_sc.uc_mcontext.sc_rdx = regs->tf_rdx; 620 sf.sf_sc.uc_mcontext.sc_rbp = regs->tf_rbp; 621 sf.sf_sc.uc_mcontext.sc_rbx = regs->tf_rbx; 622 sf.sf_sc.uc_mcontext.sc_rcx = regs->tf_rcx; 623 sf.sf_sc.uc_mcontext.sc_rax = regs->tf_rax; 624 sf.sf_sc.uc_mcontext.sc_rip = regs->tf_rip; 625 sf.sf_sc.uc_mcontext.sc_rsp = regs->tf_rsp; 626 sf.sf_sc.uc_mcontext.sc_r8 = regs->tf_r8; 627 sf.sf_sc.uc_mcontext.sc_r9 = regs->tf_r9; 628 sf.sf_sc.uc_mcontext.sc_r10 = regs->tf_r10; 629 sf.sf_sc.uc_mcontext.sc_r11 = regs->tf_r11; 630 sf.sf_sc.uc_mcontext.sc_r12 = regs->tf_r12; 631 sf.sf_sc.uc_mcontext.sc_r13 = regs->tf_r13; 632 sf.sf_sc.uc_mcontext.sc_r14 = regs->tf_r14; 633 sf.sf_sc.uc_mcontext.sc_r15 = regs->tf_r15; 634 sf.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 635 sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags; 636 sf.sf_sc.uc_mcontext.sc_err = regs->tf_err; 637 sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 638 sf.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 639 640 /* Build the argument list for the signal handler. */ 641 regs->tf_rdi = sig; /* arg 1 in %rdi */ 642 regs->tf_rax = 0; 643 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 644 regs->tf_rdx = (register_t)&sfp->sf_sc; /* arg 3 in %rdx */ 645 646 sf.sf_handler = catcher; 647 /* Fill in POSIX parts. */ 648 ksiginfo_to_lsiginfo(ksi, &sf.sf_si, sig); 649 650 /* Copy the sigframe out to the user's stack. */ 651 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 652 #ifdef DEBUG 653 printf("process %ld has trashed its stack\n", (long)p->p_pid); 654 #endif 655 PROC_LOCK(p); 656 sigexit(td, SIGILL); 657 } 658 659 regs->tf_rsp = (long)sfp; 660 regs->tf_rip = linux_rt_sigcode; 661 regs->tf_rflags &= ~(PSL_T | PSL_D); 662 regs->tf_cs = _ucodesel; 663 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 664 PROC_LOCK(p); 665 mtx_lock(&psp->ps_mtx); 666 } 667 668 /* 669 * If a Linux binary is exec'ing something, try this image activator 670 * first. We override standard shell script execution in order to 671 * be able to modify the interpreter path. We only do this if a Linux 672 * binary is doing the exec, so we do not create an EXEC module for it. 673 */ 674 static int 675 linux_exec_imgact_try(struct image_params *imgp) 676 { 677 const char *head = (const char *)imgp->image_header; 678 char *rpath; 679 int error = -1; 680 681 /* 682 * The interpreter for shell scripts run from a Linux binary needs 683 * to be located in /compat/linux if possible in order to recursively 684 * maintain Linux path emulation. 685 */ 686 if (((const short *)head)[0] == SHELLMAGIC) { 687 /* 688 * Run our normal shell image activator. If it succeeds then 689 * attempt to use the alternate path for the interpreter. If 690 * an alternate path is found, use our stringspace to store it. 691 */ 692 if ((error = exec_shell_imgact(imgp)) == 0) { 693 linux_emul_convpath(FIRST_THREAD_IN_PROC(imgp->proc), 694 imgp->interpreter_name, UIO_SYSSPACE, &rpath, 0, 695 AT_FDCWD); 696 if (rpath != NULL) 697 imgp->args->fname_buf = 698 imgp->interpreter_name = rpath; 699 } 700 } 701 return (error); 702 } 703 704 #define LINUX_VSYSCALL_START (-10UL << 20) 705 #define LINUX_VSYSCALL_SZ 1024 706 707 const unsigned long linux_vsyscall_vector[] = { 708 LINUX_SYS_gettimeofday, 709 LINUX_SYS_linux_time, 710 /* getcpu not implemented */ 711 }; 712 713 static int 714 linux_vsyscall(struct thread *td) 715 { 716 struct trapframe *frame; 717 uint64_t retqaddr; 718 int code, traced; 719 int error; 720 721 frame = td->td_frame; 722 723 /* Check %rip for vsyscall area. */ 724 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 725 return (EINVAL); 726 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 727 return (EINVAL); 728 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 729 if (code >= nitems(linux_vsyscall_vector)) 730 return (EINVAL); 731 732 /* 733 * vsyscall called as callq *(%rax), so we must 734 * use return address from %rsp and also fixup %rsp. 735 */ 736 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 737 if (error) 738 return (error); 739 740 frame->tf_rip = retqaddr; 741 frame->tf_rax = linux_vsyscall_vector[code]; 742 frame->tf_rsp += 8; 743 744 traced = (frame->tf_flags & PSL_T); 745 746 amd64_syscall(td, traced); 747 748 return (0); 749 } 750 751 struct sysentvec elf_linux_sysvec = { 752 .sv_size = LINUX_SYS_MAXSYSCALL, 753 .sv_table = linux_sysent, 754 .sv_mask = 0, 755 .sv_errsize = ELAST + 1, 756 .sv_errtbl = linux_errtbl, 757 .sv_transtrap = linux_translate_traps, 758 .sv_fixup = linux_fixup_elf, 759 .sv_sendsig = linux_rt_sendsig, 760 .sv_sigcode = &_binary_linux_locore_o_start, 761 .sv_szsigcode = &linux_szsigcode, 762 .sv_name = "Linux ELF64", 763 .sv_coredump = elf64_coredump, 764 .sv_imgact_try = linux_exec_imgact_try, 765 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 766 .sv_pagesize = PAGE_SIZE, 767 .sv_minuser = VM_MIN_ADDRESS, 768 .sv_maxuser = VM_MAXUSER_ADDRESS, 769 .sv_usrstack = USRSTACK, 770 .sv_psstrings = PS_STRINGS, 771 .sv_stackprot = VM_PROT_ALL, 772 .sv_copyout_strings = linux_copyout_strings, 773 .sv_setregs = linux_exec_setregs, 774 .sv_fixlimit = NULL, 775 .sv_maxssiz = NULL, 776 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP, 777 .sv_set_syscall_retval = linux_set_syscall_retval, 778 .sv_fetch_syscall_args = linux_fetch_syscall_args, 779 .sv_syscallnames = NULL, 780 .sv_shared_page_base = SHAREDPAGE, 781 .sv_shared_page_len = PAGE_SIZE, 782 .sv_schedtail = linux_schedtail, 783 .sv_thread_detach = linux_thread_detach, 784 .sv_trap = linux_vsyscall, 785 }; 786 787 static void 788 linux_vdso_install(void *param) 789 { 790 791 amd64_lower_shared_page(&elf_linux_sysvec); 792 793 linux_szsigcode = (&_binary_linux_locore_o_end - 794 &_binary_linux_locore_o_start); 795 796 if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len) 797 panic("Linux invalid vdso size\n"); 798 799 __elfN(linux_vdso_fixup)(&elf_linux_sysvec); 800 801 linux_shared_page_obj = __elfN(linux_shared_page_init) 802 (&linux_shared_page_mapping); 803 804 __elfN(linux_vdso_reloc)(&elf_linux_sysvec); 805 806 bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping, 807 linux_szsigcode); 808 elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj; 809 810 linux_kplatform = linux_shared_page_mapping + 811 (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base); 812 } 813 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY, 814 linux_vdso_install, NULL); 815 816 static void 817 linux_vdso_deinstall(void *param) 818 { 819 820 __elfN(linux_shared_page_fini)(linux_shared_page_obj); 821 } 822 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 823 linux_vdso_deinstall, NULL); 824 825 static char GNULINUX_ABI_VENDOR[] = "GNU"; 826 static int GNULINUX_ABI_DESC = 0; 827 828 static bool 829 linux_trans_osrel(const Elf_Note *note, int32_t *osrel) 830 { 831 const Elf32_Word *desc; 832 uintptr_t p; 833 834 p = (uintptr_t)(note + 1); 835 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 836 837 desc = (const Elf32_Word *)p; 838 if (desc[0] != GNULINUX_ABI_DESC) 839 return (false); 840 841 /* 842 * For Linux we encode osrel as follows (see linux_mib.c): 843 * VVVMMMIII (version, major, minor), see linux_mib.c. 844 */ 845 *osrel = desc[1] * 1000000 + desc[2] * 1000 + desc[3]; 846 847 return (true); 848 } 849 850 static Elf_Brandnote linux64_brandnote = { 851 .hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR), 852 .hdr.n_descsz = 16, 853 .hdr.n_type = 1, 854 .vendor = GNULINUX_ABI_VENDOR, 855 .flags = BN_TRANSLATE_OSREL, 856 .trans_osrel = linux_trans_osrel 857 }; 858 859 static Elf64_Brandinfo linux_glibc2brand = { 860 .brand = ELFOSABI_LINUX, 861 .machine = EM_X86_64, 862 .compat_3_brand = "Linux", 863 .emul_path = "/compat/linux", 864 .interp_path = "/lib64/ld-linux-x86-64.so.2", 865 .sysvec = &elf_linux_sysvec, 866 .interp_newpath = NULL, 867 .brand_note = &linux64_brandnote, 868 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 869 }; 870 871 static Elf64_Brandinfo linux_glibc2brandshort = { 872 .brand = ELFOSABI_LINUX, 873 .machine = EM_X86_64, 874 .compat_3_brand = "Linux", 875 .emul_path = "/compat/linux", 876 .interp_path = "/lib64/ld-linux.so.2", 877 .sysvec = &elf_linux_sysvec, 878 .interp_newpath = NULL, 879 .brand_note = &linux64_brandnote, 880 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 881 }; 882 883 static Elf64_Brandinfo linux_muslbrand = { 884 .brand = ELFOSABI_LINUX, 885 .machine = EM_X86_64, 886 .compat_3_brand = "Linux", 887 .emul_path = "/compat/linux", 888 .interp_path = "/lib/ld-musl-x86_64.so.1", 889 .sysvec = &elf_linux_sysvec, 890 .interp_newpath = NULL, 891 .brand_note = &linux64_brandnote, 892 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 893 }; 894 895 Elf64_Brandinfo *linux_brandlist[] = { 896 &linux_glibc2brand, 897 &linux_glibc2brandshort, 898 &linux_muslbrand, 899 NULL 900 }; 901 902 static int 903 linux64_elf_modevent(module_t mod, int type, void *data) 904 { 905 Elf64_Brandinfo **brandinfo; 906 int error; 907 struct linux_ioctl_handler **lihp; 908 909 error = 0; 910 911 switch(type) { 912 case MOD_LOAD: 913 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 914 ++brandinfo) 915 if (elf64_insert_brand_entry(*brandinfo) < 0) 916 error = EINVAL; 917 if (error == 0) { 918 SET_FOREACH(lihp, linux_ioctl_handler_set) 919 linux_ioctl_register_handler(*lihp); 920 LIST_INIT(&futex_list); 921 mtx_init(&futex_mtx, "ftllk64", NULL, MTX_DEF); 922 stclohz = (stathz ? stathz : hz); 923 if (bootverbose) 924 printf("Linux x86-64 ELF exec handler installed\n"); 925 } else 926 printf("cannot insert Linux x86-64 ELF brand handler\n"); 927 break; 928 case MOD_UNLOAD: 929 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 930 ++brandinfo) 931 if (elf64_brand_inuse(*brandinfo)) 932 error = EBUSY; 933 if (error == 0) { 934 for (brandinfo = &linux_brandlist[0]; 935 *brandinfo != NULL; ++brandinfo) 936 if (elf64_remove_brand_entry(*brandinfo) < 0) 937 error = EINVAL; 938 } 939 if (error == 0) { 940 SET_FOREACH(lihp, linux_ioctl_handler_set) 941 linux_ioctl_unregister_handler(*lihp); 942 mtx_destroy(&futex_mtx); 943 if (bootverbose) 944 printf("Linux ELF exec handler removed\n"); 945 } else 946 printf("Could not deinstall ELF interpreter entry\n"); 947 break; 948 default: 949 return (EOPNOTSUPP); 950 } 951 return (error); 952 } 953 954 static moduledata_t linux64_elf_mod = { 955 "linux64elf", 956 linux64_elf_modevent, 957 0 958 }; 959 960 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 961 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 962 FEATURE(linux64, "Linux 64bit support"); 963