1 /*- 2 * Copyright (c) 2004 Tim J. Robbins 3 * Copyright (c) 2003 Peter Wemm 4 * Copyright (c) 2002 Doug Rabson 5 * Copyright (c) 1998-1999 Andrew Gallatin 6 * Copyright (c) 1994-1996 Søren Schmidt 7 * All rights reserved. 8 * Copyright (c) 2013, 2021 Dmitry Chagin <dchagin@FreeBSD.org> 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 #define __ELF_WORD_SIZE 64 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/exec.h> 42 #include <sys/fcntl.h> 43 #include <sys/imgact.h> 44 #include <sys/imgact_elf.h> 45 #include <sys/kernel.h> 46 #include <sys/ktr.h> 47 #include <sys/lock.h> 48 #include <sys/malloc.h> 49 #include <sys/module.h> 50 #include <sys/mutex.h> 51 #include <sys/proc.h> 52 #include <sys/resourcevar.h> 53 #include <sys/stddef.h> 54 #include <sys/signalvar.h> 55 #include <sys/syscallsubr.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/sysproto.h> 59 #include <sys/vnode.h> 60 #include <sys/eventhandler.h> 61 62 #include <vm/vm.h> 63 #include <vm/pmap.h> 64 #include <vm/vm_extern.h> 65 #include <vm/vm_map.h> 66 #include <vm/vm_object.h> 67 #include <vm/vm_page.h> 68 #include <vm/vm_param.h> 69 70 #include <machine/cpu.h> 71 #include <machine/md_var.h> 72 #include <machine/pcb.h> 73 #include <machine/specialreg.h> 74 #include <machine/trap.h> 75 76 #include <x86/linux/linux_x86.h> 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_ioctl.h> 81 #include <compat/linux/linux_mib.h> 82 #include <compat/linux/linux_misc.h> 83 #include <compat/linux/linux_signal.h> 84 #include <compat/linux/linux_sysproto.h> 85 #include <compat/linux/linux_util.h> 86 #include <compat/linux/linux_vdso.h> 87 88 MODULE_VERSION(linux64, 1); 89 90 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 91 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \ 92 LINUX_VDSOPAGE_SIZE) 93 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE) 94 /* 95 * PAGE_SIZE - the size 96 * of the native SHAREDPAGE 97 */ 98 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48 99 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \ 100 sizeof(struct ps_strings)) 101 102 static int linux_szsigcode; 103 static vm_object_t linux_vdso_obj; 104 static char *linux_vdso_mapping; 105 extern char _binary_linux_vdso_so_o_start; 106 extern char _binary_linux_vdso_so_o_end; 107 static vm_offset_t linux_vdso_base; 108 109 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 110 111 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 112 113 static int linux_copyout_strings(struct image_params *imgp, 114 uintptr_t *stack_base); 115 static int linux_fixup_elf(uintptr_t *stack_base, 116 struct image_params *iparams); 117 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel); 118 static void linux_vdso_install(const void *param); 119 static void linux_vdso_deinstall(const void *param); 120 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 121 static void linux_set_syscall_retval(struct thread *td, int error); 122 static int linux_fetch_syscall_args(struct thread *td); 123 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 124 uintptr_t stack); 125 static void linux_exec_sysvec_init(void *param); 126 static int linux_on_exec_vmspace(struct proc *p, 127 struct image_params *imgp); 128 static int linux_vsyscall(struct thread *td); 129 130 #define LINUX_T_UNKNOWN 255 131 static int _bsd_to_linux_trapcode[] = { 132 LINUX_T_UNKNOWN, /* 0 */ 133 6, /* 1 T_PRIVINFLT */ 134 LINUX_T_UNKNOWN, /* 2 */ 135 3, /* 3 T_BPTFLT */ 136 LINUX_T_UNKNOWN, /* 4 */ 137 LINUX_T_UNKNOWN, /* 5 */ 138 16, /* 6 T_ARITHTRAP */ 139 254, /* 7 T_ASTFLT */ 140 LINUX_T_UNKNOWN, /* 8 */ 141 13, /* 9 T_PROTFLT */ 142 1, /* 10 T_TRCTRAP */ 143 LINUX_T_UNKNOWN, /* 11 */ 144 14, /* 12 T_PAGEFLT */ 145 LINUX_T_UNKNOWN, /* 13 */ 146 17, /* 14 T_ALIGNFLT */ 147 LINUX_T_UNKNOWN, /* 15 */ 148 LINUX_T_UNKNOWN, /* 16 */ 149 LINUX_T_UNKNOWN, /* 17 */ 150 0, /* 18 T_DIVIDE */ 151 2, /* 19 T_NMI */ 152 4, /* 20 T_OFLOW */ 153 5, /* 21 T_BOUND */ 154 7, /* 22 T_DNA */ 155 8, /* 23 T_DOUBLEFLT */ 156 9, /* 24 T_FPOPFLT */ 157 10, /* 25 T_TSSFLT */ 158 11, /* 26 T_SEGNPFLT */ 159 12, /* 27 T_STKFLT */ 160 18, /* 28 T_MCHK */ 161 19, /* 29 T_XMMFLT */ 162 15 /* 30 T_RESERVED */ 163 }; 164 #define bsd_to_linux_trapcode(code) \ 165 ((code)<nitems(_bsd_to_linux_trapcode)? \ 166 _bsd_to_linux_trapcode[(code)]: \ 167 LINUX_T_UNKNOWN) 168 169 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 170 LINUX_VDSO_SYM_CHAR(linux_platform); 171 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 172 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 173 174 /* 175 * If FreeBSD & Linux have a difference of opinion about what a trap 176 * means, deal with it here. 177 * 178 * MPSAFE 179 */ 180 static int 181 linux_translate_traps(int signal, int trap_code) 182 { 183 184 if (signal != SIGBUS) 185 return (signal); 186 switch (trap_code) { 187 case T_PROTFLT: 188 case T_TSSFLT: 189 case T_DOUBLEFLT: 190 case T_PAGEFLT: 191 return (SIGSEGV); 192 default: 193 return (signal); 194 } 195 } 196 197 static int 198 linux_fetch_syscall_args(struct thread *td) 199 { 200 struct proc *p; 201 struct trapframe *frame; 202 struct syscall_args *sa; 203 204 p = td->td_proc; 205 frame = td->td_frame; 206 sa = &td->td_sa; 207 208 sa->args[0] = frame->tf_rdi; 209 sa->args[1] = frame->tf_rsi; 210 sa->args[2] = frame->tf_rdx; 211 sa->args[3] = frame->tf_rcx; 212 sa->args[4] = frame->tf_r8; 213 sa->args[5] = frame->tf_r9; 214 sa->code = frame->tf_rax; 215 sa->original_code = sa->code; 216 217 if (sa->code >= p->p_sysent->sv_size) 218 /* nosys */ 219 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 220 else 221 sa->callp = &p->p_sysent->sv_table[sa->code]; 222 223 td->td_retval[0] = 0; 224 return (0); 225 } 226 227 static void 228 linux_set_syscall_retval(struct thread *td, int error) 229 { 230 struct trapframe *frame; 231 232 frame = td->td_frame; 233 234 switch (error) { 235 case 0: 236 frame->tf_rax = td->td_retval[0]; 237 frame->tf_r10 = frame->tf_rcx; 238 break; 239 240 case ERESTART: 241 /* 242 * Reconstruct pc, we know that 'syscall' is 2 bytes, 243 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 244 * We saved this in tf_err. 245 * 246 */ 247 frame->tf_rip -= frame->tf_err; 248 frame->tf_r10 = frame->tf_rcx; 249 break; 250 251 case EJUSTRETURN: 252 break; 253 254 default: 255 frame->tf_rax = bsd_to_linux_errno(error); 256 frame->tf_r10 = frame->tf_rcx; 257 break; 258 } 259 260 /* 261 * Differently from FreeBSD native ABI, on Linux only %rcx 262 * and %r11 values are not preserved across the syscall. 263 * Require full context restore to get all registers except 264 * those two restored at return to usermode. 265 * 266 * XXX: Would be great to be able to avoid PCB_FULL_IRET 267 * for the error == 0 case. 268 */ 269 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 270 } 271 272 static int 273 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base) 274 { 275 Elf_Auxargs *args; 276 Elf_Auxinfo *argarray, *pos; 277 struct proc *p; 278 int error, issetugid; 279 280 p = imgp->proc; 281 args = (Elf64_Auxargs *)imgp->auxargs; 282 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 283 M_WAITOK | M_ZERO); 284 285 issetugid = p->p_flag & P_SUGID ? 1 : 0; 286 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 287 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 288 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 289 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 290 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 291 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 292 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 293 AUXARGS_ENTRY(pos, AT_BASE, args->base); 294 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 295 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 296 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 297 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 298 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 299 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 300 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 301 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary); 302 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0); 303 if (imgp->execpathp != 0) 304 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp); 305 if (args->execfd != -1) 306 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 307 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 308 AUXARGS_ENTRY(pos, AT_NULL, 0); 309 310 free(imgp->auxargs, M_TEMP); 311 imgp->auxargs = NULL; 312 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 313 314 error = copyout(argarray, (void *)base, 315 sizeof(*argarray) * LINUX_AT_COUNT); 316 free(argarray, M_TEMP); 317 return (error); 318 } 319 320 static int 321 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp) 322 { 323 Elf_Addr *base; 324 325 base = (Elf64_Addr *)*stack_base; 326 base--; 327 if (suword(base, (uint64_t)imgp->args->argc) == -1) 328 return (EFAULT); 329 330 *stack_base = (uintptr_t)base; 331 return (0); 332 } 333 334 /* 335 * Copy strings out to the new process address space, constructing new arg 336 * and env vector tables. Return a pointer to the base so that it can be used 337 * as the initial stack pointer. 338 */ 339 static int 340 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 341 { 342 int argc, envc, error; 343 char **vectp; 344 char *stringp; 345 uintptr_t destp, ustringp; 346 struct ps_strings *arginfo; 347 char canary[LINUX_AT_RANDOM_LEN]; 348 size_t execpath_len; 349 struct proc *p; 350 351 /* Calculate string base and vector table pointers. */ 352 if (imgp->execpath != NULL && imgp->auxargs != NULL) 353 execpath_len = strlen(imgp->execpath) + 1; 354 else 355 execpath_len = 0; 356 357 p = imgp->proc; 358 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 359 destp = (uintptr_t)arginfo; 360 361 if (execpath_len != 0) { 362 destp -= execpath_len; 363 destp = rounddown2(destp, sizeof(void *)); 364 imgp->execpathp = (void *)destp; 365 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 366 if (error != 0) 367 return (error); 368 } 369 370 /* Prepare the canary for SSP. */ 371 arc4rand(canary, sizeof(canary), 0); 372 destp -= roundup(sizeof(canary), sizeof(void *)); 373 imgp->canary = (void *)destp; 374 error = copyout(canary, imgp->canary, sizeof(canary)); 375 if (error != 0) 376 return (error); 377 378 /* Allocate room for the argument and environment strings. */ 379 destp -= ARG_MAX - imgp->args->stringspace; 380 destp = rounddown2(destp, sizeof(void *)); 381 ustringp = destp; 382 383 if (imgp->auxargs) { 384 /* 385 * Allocate room on the stack for the ELF auxargs 386 * array. It has LINUX_AT_COUNT entries. 387 */ 388 destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo); 389 destp = rounddown2(destp, sizeof(void *)); 390 } 391 392 vectp = (char **)destp; 393 394 /* 395 * Allocate room for the argv[] and env vectors including the 396 * terminating NULL pointers. 397 */ 398 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 399 400 /* 401 * Starting with 2.24, glibc depends on a 16-byte stack alignment. 402 * One "long argc" will be prepended later. 403 */ 404 vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8); 405 406 /* vectp also becomes our initial stack base. */ 407 *stack_base = (uintptr_t)vectp; 408 409 stringp = imgp->args->begin_argv; 410 argc = imgp->args->argc; 411 envc = imgp->args->envc; 412 413 /* Copy out strings - arguments and environment. */ 414 error = copyout(stringp, (void *)ustringp, 415 ARG_MAX - imgp->args->stringspace); 416 if (error != 0) 417 return (error); 418 419 /* Fill in "ps_strings" struct for ps, w, etc. */ 420 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 421 suword(&arginfo->ps_nargvstr, argc) != 0) 422 return (EFAULT); 423 424 /* Fill in argument portion of vector table. */ 425 for (; argc > 0; --argc) { 426 if (suword(vectp++, ustringp) != 0) 427 return (EFAULT); 428 while (*stringp++ != 0) 429 ustringp++; 430 ustringp++; 431 } 432 433 /* A null vector table pointer separates the argp's from the envp's. */ 434 if (suword(vectp++, 0) != 0) 435 return (EFAULT); 436 437 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 438 suword(&arginfo->ps_nenvstr, envc) != 0) 439 return (EFAULT); 440 441 /* Fill in environment portion of vector table. */ 442 for (; envc > 0; --envc) { 443 if (suword(vectp++, ustringp) != 0) 444 return (EFAULT); 445 while (*stringp++ != 0) 446 ustringp++; 447 ustringp++; 448 } 449 450 /* The end of the vector table is a null pointer. */ 451 if (suword(vectp, 0) != 0) 452 return (EFAULT); 453 454 if (imgp->auxargs) { 455 vectp++; 456 error = imgp->sysent->sv_copyout_auxargs(imgp, 457 (uintptr_t)vectp); 458 if (error != 0) 459 return (error); 460 } 461 462 return (0); 463 } 464 465 /* 466 * Reset registers to default values on exec. 467 */ 468 static void 469 linux_exec_setregs(struct thread *td, struct image_params *imgp, 470 uintptr_t stack) 471 { 472 struct trapframe *regs; 473 struct pcb *pcb; 474 register_t saved_rflags; 475 476 regs = td->td_frame; 477 pcb = td->td_pcb; 478 479 if (td->td_proc->p_md.md_ldt != NULL) 480 user_ldt_free(td); 481 482 pcb->pcb_fsbase = 0; 483 pcb->pcb_gsbase = 0; 484 clear_pcb_flags(pcb, PCB_32BIT); 485 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 486 set_pcb_flags(pcb, PCB_FULL_IRET); 487 488 saved_rflags = regs->tf_rflags & PSL_T; 489 bzero((char *)regs, sizeof(struct trapframe)); 490 regs->tf_rip = imgp->entry_addr; 491 regs->tf_rsp = stack; 492 regs->tf_rflags = PSL_USER | saved_rflags; 493 regs->tf_ss = _udatasel; 494 regs->tf_cs = _ucodesel; 495 regs->tf_ds = _udatasel; 496 regs->tf_es = _udatasel; 497 regs->tf_fs = _ufssel; 498 regs->tf_gs = _ugssel; 499 regs->tf_flags = TF_HASSEGS; 500 501 x86_clear_dbregs(pcb); 502 503 /* 504 * Drop the FP state if we hold it, so that the process gets a 505 * clean FP state if it uses the FPU again. 506 */ 507 fpstate_drop(td); 508 } 509 510 /* 511 * Copied from amd64/amd64/machdep.c 512 * 513 * XXX fpu state need? don't think so 514 */ 515 int 516 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 517 { 518 struct proc *p; 519 struct l_ucontext uc; 520 struct l_sigcontext *context; 521 struct trapframe *regs; 522 unsigned long rflags; 523 int error; 524 ksiginfo_t ksi; 525 526 regs = td->td_frame; 527 error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc)); 528 if (error != 0) 529 return (error); 530 531 p = td->td_proc; 532 context = &uc.uc_mcontext; 533 rflags = context->sc_rflags; 534 535 /* 536 * Don't allow users to change privileged or reserved flags. 537 */ 538 /* 539 * XXX do allow users to change the privileged flag PSL_RF. 540 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 541 * should sometimes set it there too. tf_rflags is kept in 542 * the signal context during signal handling and there is no 543 * other place to remember it, so the PSL_RF bit may be 544 * corrupted by the signal handler without us knowing. 545 * Corruption of the PSL_RF bit at worst causes one more or 546 * one less debugger trap, so allowing it is fairly harmless. 547 */ 548 549 #define RFLAG_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 550 if (!RFLAG_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 551 printf("linux_rt_sigreturn: rflags = 0x%lx\n", rflags); 552 return (EINVAL); 553 } 554 555 /* 556 * Don't allow users to load a valid privileged %cs. Let the 557 * hardware check for invalid selectors, excess privilege in 558 * other selectors, invalid %eip's and invalid %esp's. 559 */ 560 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 561 if (!CS_SECURE(context->sc_cs)) { 562 printf("linux_rt_sigreturn: cs = 0x%x\n", context->sc_cs); 563 ksiginfo_init_trap(&ksi); 564 ksi.ksi_signo = SIGBUS; 565 ksi.ksi_code = BUS_OBJERR; 566 ksi.ksi_trapno = T_PROTFLT; 567 ksi.ksi_addr = (void *)regs->tf_rip; 568 trapsignal(td, &ksi); 569 return (EINVAL); 570 } 571 572 PROC_LOCK(p); 573 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask); 574 SIG_CANTMASK(td->td_sigmask); 575 signotify(td); 576 PROC_UNLOCK(p); 577 578 regs->tf_rdi = context->sc_rdi; 579 regs->tf_rsi = context->sc_rsi; 580 regs->tf_rdx = context->sc_rdx; 581 regs->tf_rbp = context->sc_rbp; 582 regs->tf_rbx = context->sc_rbx; 583 regs->tf_rcx = context->sc_rcx; 584 regs->tf_rax = context->sc_rax; 585 regs->tf_rip = context->sc_rip; 586 regs->tf_rsp = context->sc_rsp; 587 regs->tf_r8 = context->sc_r8; 588 regs->tf_r9 = context->sc_r9; 589 regs->tf_r10 = context->sc_r10; 590 regs->tf_r11 = context->sc_r11; 591 regs->tf_r12 = context->sc_r12; 592 regs->tf_r13 = context->sc_r13; 593 regs->tf_r14 = context->sc_r14; 594 regs->tf_r15 = context->sc_r15; 595 regs->tf_cs = context->sc_cs; 596 regs->tf_err = context->sc_err; 597 regs->tf_rflags = rflags; 598 599 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 600 return (EJUSTRETURN); 601 } 602 603 /* 604 * copied from amd64/amd64/machdep.c 605 * 606 * Send an interrupt to process. 607 */ 608 static void 609 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 610 { 611 struct l_rt_sigframe sf, *sfp; 612 struct proc *p; 613 struct thread *td; 614 struct sigacts *psp; 615 caddr_t sp; 616 struct trapframe *regs; 617 int sig, code; 618 int oonstack; 619 620 td = curthread; 621 p = td->td_proc; 622 PROC_LOCK_ASSERT(p, MA_OWNED); 623 sig = ksi->ksi_signo; 624 psp = p->p_sigacts; 625 code = ksi->ksi_code; 626 mtx_assert(&psp->ps_mtx, MA_OWNED); 627 regs = td->td_frame; 628 oonstack = sigonstack(regs->tf_rsp); 629 630 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 631 catcher, sig, mask, code); 632 633 /* Save user context. */ 634 bzero(&sf, sizeof(sf)); 635 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask); 636 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask); 637 638 sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 639 sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 640 sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 641 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 642 643 sf.sf_sc.uc_mcontext.sc_rdi = regs->tf_rdi; 644 sf.sf_sc.uc_mcontext.sc_rsi = regs->tf_rsi; 645 sf.sf_sc.uc_mcontext.sc_rdx = regs->tf_rdx; 646 sf.sf_sc.uc_mcontext.sc_rbp = regs->tf_rbp; 647 sf.sf_sc.uc_mcontext.sc_rbx = regs->tf_rbx; 648 sf.sf_sc.uc_mcontext.sc_rcx = regs->tf_rcx; 649 sf.sf_sc.uc_mcontext.sc_rax = regs->tf_rax; 650 sf.sf_sc.uc_mcontext.sc_rip = regs->tf_rip; 651 sf.sf_sc.uc_mcontext.sc_rsp = regs->tf_rsp; 652 sf.sf_sc.uc_mcontext.sc_r8 = regs->tf_r8; 653 sf.sf_sc.uc_mcontext.sc_r9 = regs->tf_r9; 654 sf.sf_sc.uc_mcontext.sc_r10 = regs->tf_r10; 655 sf.sf_sc.uc_mcontext.sc_r11 = regs->tf_r11; 656 sf.sf_sc.uc_mcontext.sc_r12 = regs->tf_r12; 657 sf.sf_sc.uc_mcontext.sc_r13 = regs->tf_r13; 658 sf.sf_sc.uc_mcontext.sc_r14 = regs->tf_r14; 659 sf.sf_sc.uc_mcontext.sc_r15 = regs->tf_r15; 660 sf.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 661 sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags; 662 sf.sf_sc.uc_mcontext.sc_err = regs->tf_err; 663 sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 664 sf.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 665 666 /* Allocate space for the signal handler context. */ 667 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 668 SIGISMEMBER(psp->ps_sigonstack, sig)) { 669 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size - 670 sizeof(struct l_rt_sigframe); 671 } else 672 sp = (caddr_t)regs->tf_rsp - sizeof(struct l_rt_sigframe) - 128; 673 /* Align to 16 bytes. */ 674 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 675 676 /* Translate the signal. */ 677 sig = bsd_to_linux_signal(sig); 678 679 /* Build the argument list for the signal handler. */ 680 regs->tf_rdi = sig; /* arg 1 in %rdi */ 681 regs->tf_rax = 0; 682 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 683 regs->tf_rdx = (register_t)&sfp->sf_sc; /* arg 3 in %rdx */ 684 685 /* Fill in POSIX parts. */ 686 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 687 sf.sf_handler = catcher; 688 689 mtx_unlock(&psp->ps_mtx); 690 PROC_UNLOCK(p); 691 692 /* Copy the sigframe out to the user's stack. */ 693 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 694 PROC_LOCK(p); 695 sigexit(td, SIGILL); 696 } 697 698 regs->tf_rsp = (long)sfp; 699 regs->tf_rip = linux_rt_sigcode; 700 regs->tf_rflags &= ~(PSL_T | PSL_D); 701 regs->tf_cs = _ucodesel; 702 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 703 PROC_LOCK(p); 704 mtx_lock(&psp->ps_mtx); 705 } 706 707 #define LINUX_VSYSCALL_START (-10UL << 20) 708 #define LINUX_VSYSCALL_SZ 1024 709 710 const unsigned long linux_vsyscall_vector[] = { 711 LINUX_SYS_gettimeofday, 712 LINUX_SYS_linux_time, 713 LINUX_SYS_linux_getcpu, 714 }; 715 716 static int 717 linux_vsyscall(struct thread *td) 718 { 719 struct trapframe *frame; 720 uint64_t retqaddr; 721 int code, traced; 722 int error; 723 724 frame = td->td_frame; 725 726 /* Check %rip for vsyscall area. */ 727 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 728 return (EINVAL); 729 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 730 return (EINVAL); 731 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 732 if (code >= nitems(linux_vsyscall_vector)) 733 return (EINVAL); 734 735 /* 736 * vsyscall called as callq *(%rax), so we must 737 * use return address from %rsp and also fixup %rsp. 738 */ 739 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 740 if (error) 741 return (error); 742 743 frame->tf_rip = retqaddr; 744 frame->tf_rax = linux_vsyscall_vector[code]; 745 frame->tf_rsp += 8; 746 747 traced = (frame->tf_flags & PSL_T); 748 749 amd64_syscall(td, traced); 750 751 return (0); 752 } 753 754 struct sysentvec elf_linux_sysvec = { 755 .sv_size = LINUX_SYS_MAXSYSCALL, 756 .sv_table = linux_sysent, 757 .sv_transtrap = linux_translate_traps, 758 .sv_fixup = linux_fixup_elf, 759 .sv_sendsig = linux_rt_sendsig, 760 .sv_sigcode = &_binary_linux_vdso_so_o_start, 761 .sv_szsigcode = &linux_szsigcode, 762 .sv_name = "Linux ELF64", 763 .sv_coredump = elf64_coredump, 764 .sv_elf_core_osabi = ELFOSABI_NONE, 765 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 766 .sv_elf_core_prepare_notes = linux64_prepare_notes, 767 .sv_imgact_try = linux_exec_imgact_try, 768 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 769 .sv_minuser = VM_MIN_ADDRESS, 770 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 771 .sv_usrstack = LINUX_USRSTACK_LA48, 772 .sv_psstrings = LINUX_PS_STRINGS_LA48, 773 .sv_stackprot = VM_PROT_ALL, 774 .sv_copyout_auxargs = linux_copyout_auxargs, 775 .sv_copyout_strings = linux_copyout_strings, 776 .sv_setregs = linux_exec_setregs, 777 .sv_fixlimit = NULL, 778 .sv_maxssiz = NULL, 779 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 780 SV_SIG_WAITNDQ | SV_TIMEKEEP, 781 .sv_set_syscall_retval = linux_set_syscall_retval, 782 .sv_fetch_syscall_args = linux_fetch_syscall_args, 783 .sv_syscallnames = NULL, 784 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 785 .sv_shared_page_len = PAGE_SIZE, 786 .sv_schedtail = linux_schedtail, 787 .sv_thread_detach = linux_thread_detach, 788 .sv_trap = linux_vsyscall, 789 .sv_onexec = linux_on_exec_vmspace, 790 .sv_onexit = linux_on_exit, 791 .sv_ontdexit = linux_thread_dtor, 792 .sv_setid_allowed = &linux_setid_allowed_query, 793 }; 794 795 static int 796 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 797 { 798 int error; 799 800 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 801 LINUX_VDSOPAGE_SIZE, imgp); 802 if (error == 0) 803 linux_on_exec(p, imgp); 804 return (error); 805 } 806 807 /* 808 * linux_vdso_install() and linux_exec_sysvec_init() must be called 809 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 810 */ 811 static void 812 linux_exec_sysvec_init(void *param) 813 { 814 l_uintptr_t *ktimekeep_base, *ktsc_selector; 815 struct sysentvec *sv; 816 ptrdiff_t tkoff; 817 818 sv = param; 819 amd64_lower_shared_page(sv); 820 /* Fill timekeep_base */ 821 exec_sysvec_init(sv); 822 823 tkoff = kern_timekeep_base - linux_vdso_base; 824 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 825 *ktimekeep_base = sv->sv_timekeep_base; 826 827 tkoff = kern_tsc_selector - linux_vdso_base; 828 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 829 *ktsc_selector = linux_vdso_tsc_selector_idx(); 830 if (bootverbose) 831 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector); 832 } 833 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 834 linux_exec_sysvec_init, &elf_linux_sysvec); 835 836 static void 837 linux_vdso_install(const void *param) 838 { 839 char *vdso_start = &_binary_linux_vdso_so_o_start; 840 char *vdso_end = &_binary_linux_vdso_so_o_end; 841 842 linux_szsigcode = vdso_end - vdso_start; 843 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 844 845 linux_vdso_base = LINUX_VDSOPAGE_LA48; 846 if (hw_lower_amd64_sharedpage != 0) 847 linux_vdso_base -= PAGE_SIZE; 848 849 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 850 851 linux_vdso_obj = __elfN(linux_shared_page_init) 852 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 853 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 854 855 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 856 } 857 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 858 linux_vdso_install, NULL); 859 860 static void 861 linux_vdso_deinstall(const void *param) 862 { 863 864 __elfN(linux_shared_page_fini)(linux_vdso_obj, 865 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 866 } 867 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 868 linux_vdso_deinstall, NULL); 869 870 static void 871 linux_vdso_reloc(char *mapping, Elf_Addr offset) 872 { 873 const Elf_Ehdr *ehdr; 874 const Elf_Shdr *shdr; 875 Elf64_Addr *where, val; 876 Elf_Size rtype, symidx; 877 const Elf_Rela *rela; 878 Elf_Addr addr, addend; 879 int relacnt; 880 int i, j; 881 882 MPASS(offset != 0); 883 884 relacnt = 0; 885 ehdr = (const Elf_Ehdr *)mapping; 886 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 887 for (i = 0; i < ehdr->e_shnum; i++) 888 { 889 switch (shdr[i].sh_type) { 890 case SHT_REL: 891 printf("Linux x86_64 vDSO: unexpected Rel section\n"); 892 break; 893 case SHT_RELA: 894 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset); 895 relacnt = shdr[i].sh_size / sizeof(*rela); 896 } 897 } 898 899 for (j = 0; j < relacnt; j++, rela++) { 900 where = (Elf_Addr *)(mapping + rela->r_offset); 901 addend = rela->r_addend; 902 rtype = ELF_R_TYPE(rela->r_info); 903 symidx = ELF_R_SYM(rela->r_info); 904 905 switch (rtype) { 906 case R_X86_64_NONE: /* none */ 907 break; 908 909 case R_X86_64_RELATIVE: /* B + A */ 910 addr = (Elf_Addr)(offset + addend); 911 val = addr; 912 if (*where != val) 913 *where = val; 914 break; 915 case R_X86_64_IRELATIVE: 916 printf("Linux x86_64 vDSO: unexpected ifunc relocation, " 917 "symbol index %ld\n", symidx); 918 break; 919 default: 920 printf("Linux x86_64 vDSO: unexpected relocation type %ld, " 921 "symbol index %ld\n", rtype, symidx); 922 } 923 } 924 } 925 926 static char GNULINUX_ABI_VENDOR[] = "GNU"; 927 static int GNULINUX_ABI_DESC = 0; 928 929 static bool 930 linux_trans_osrel(const Elf_Note *note, int32_t *osrel) 931 { 932 const Elf32_Word *desc; 933 uintptr_t p; 934 935 p = (uintptr_t)(note + 1); 936 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 937 938 desc = (const Elf32_Word *)p; 939 if (desc[0] != GNULINUX_ABI_DESC) 940 return (false); 941 942 /* 943 * For Linux we encode osrel using the Linux convention of 944 * (version << 16) | (major << 8) | (minor) 945 * See macro in linux_mib.h 946 */ 947 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]); 948 949 return (true); 950 } 951 952 static Elf_Brandnote linux64_brandnote = { 953 .hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR), 954 .hdr.n_descsz = 16, 955 .hdr.n_type = 1, 956 .vendor = GNULINUX_ABI_VENDOR, 957 .flags = BN_TRANSLATE_OSREL, 958 .trans_osrel = linux_trans_osrel 959 }; 960 961 static Elf64_Brandinfo linux_glibc2brand = { 962 .brand = ELFOSABI_LINUX, 963 .machine = EM_X86_64, 964 .compat_3_brand = "Linux", 965 .emul_path = linux_emul_path, 966 .interp_path = "/lib64/ld-linux-x86-64.so.2", 967 .sysvec = &elf_linux_sysvec, 968 .interp_newpath = NULL, 969 .brand_note = &linux64_brandnote, 970 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 971 }; 972 973 static Elf64_Brandinfo linux_glibc2brandshort = { 974 .brand = ELFOSABI_LINUX, 975 .machine = EM_X86_64, 976 .compat_3_brand = "Linux", 977 .emul_path = linux_emul_path, 978 .interp_path = "/lib64/ld-linux.so.2", 979 .sysvec = &elf_linux_sysvec, 980 .interp_newpath = NULL, 981 .brand_note = &linux64_brandnote, 982 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 983 }; 984 985 static Elf64_Brandinfo linux_muslbrand = { 986 .brand = ELFOSABI_LINUX, 987 .machine = EM_X86_64, 988 .compat_3_brand = "Linux", 989 .emul_path = linux_emul_path, 990 .interp_path = "/lib/ld-musl-x86_64.so.1", 991 .sysvec = &elf_linux_sysvec, 992 .interp_newpath = NULL, 993 .brand_note = &linux64_brandnote, 994 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 995 LINUX_BI_FUTEX_REQUEUE 996 }; 997 998 Elf64_Brandinfo *linux_brandlist[] = { 999 &linux_glibc2brand, 1000 &linux_glibc2brandshort, 1001 &linux_muslbrand, 1002 NULL 1003 }; 1004 1005 static int 1006 linux64_elf_modevent(module_t mod, int type, void *data) 1007 { 1008 Elf64_Brandinfo **brandinfo; 1009 int error; 1010 struct linux_ioctl_handler **lihp; 1011 1012 error = 0; 1013 1014 switch(type) { 1015 case MOD_LOAD: 1016 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1017 ++brandinfo) 1018 if (elf64_insert_brand_entry(*brandinfo) < 0) 1019 error = EINVAL; 1020 if (error == 0) { 1021 SET_FOREACH(lihp, linux_ioctl_handler_set) 1022 linux_ioctl_register_handler(*lihp); 1023 stclohz = (stathz ? stathz : hz); 1024 if (bootverbose) 1025 printf("Linux x86-64 ELF exec handler installed\n"); 1026 } else 1027 printf("cannot insert Linux x86-64 ELF brand handler\n"); 1028 break; 1029 case MOD_UNLOAD: 1030 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1031 ++brandinfo) 1032 if (elf64_brand_inuse(*brandinfo)) 1033 error = EBUSY; 1034 if (error == 0) { 1035 for (brandinfo = &linux_brandlist[0]; 1036 *brandinfo != NULL; ++brandinfo) 1037 if (elf64_remove_brand_entry(*brandinfo) < 0) 1038 error = EINVAL; 1039 } 1040 if (error == 0) { 1041 SET_FOREACH(lihp, linux_ioctl_handler_set) 1042 linux_ioctl_unregister_handler(*lihp); 1043 if (bootverbose) 1044 printf("Linux x86_64 ELF exec handler removed\n"); 1045 } else 1046 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n"); 1047 break; 1048 default: 1049 return (EOPNOTSUPP); 1050 } 1051 return (error); 1052 } 1053 1054 static moduledata_t linux64_elf_mod = { 1055 "linux64elf", 1056 linux64_elf_modevent, 1057 0 1058 }; 1059 1060 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1061 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 1062 FEATURE(linux64, "Linux 64bit support"); 1063