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_fork.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 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 92 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \ 93 LINUX_VDSOPAGE_SIZE) 94 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE) 95 /* 96 * PAGE_SIZE - the size 97 * of the native SHAREDPAGE 98 */ 99 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48 100 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \ 101 sizeof(struct ps_strings)) 102 103 static int linux_szsigcode; 104 static vm_object_t linux_vdso_obj; 105 static char *linux_vdso_mapping; 106 extern char _binary_linux_vdso_so_o_start; 107 extern char _binary_linux_vdso_so_o_end; 108 static vm_offset_t linux_vdso_base; 109 110 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 111 112 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 113 114 static int linux_copyout_strings(struct image_params *imgp, 115 uintptr_t *stack_base); 116 static int linux_fixup_elf(uintptr_t *stack_base, 117 struct image_params *iparams); 118 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel); 119 static void linux_vdso_install(const void *param); 120 static void linux_vdso_deinstall(const void *param); 121 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 122 static void linux_set_syscall_retval(struct thread *td, int error); 123 static int linux_fetch_syscall_args(struct thread *td); 124 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 125 uintptr_t stack); 126 static void linux_exec_sysvec_init(void *param); 127 static int linux_on_exec_vmspace(struct proc *p, 128 struct image_params *imgp); 129 static void linux_set_fork_retval(struct thread *td); 130 static int linux_vsyscall(struct thread *td); 131 132 #define LINUX_T_UNKNOWN 255 133 static int _bsd_to_linux_trapcode[] = { 134 LINUX_T_UNKNOWN, /* 0 */ 135 6, /* 1 T_PRIVINFLT */ 136 LINUX_T_UNKNOWN, /* 2 */ 137 3, /* 3 T_BPTFLT */ 138 LINUX_T_UNKNOWN, /* 4 */ 139 LINUX_T_UNKNOWN, /* 5 */ 140 16, /* 6 T_ARITHTRAP */ 141 254, /* 7 T_ASTFLT */ 142 LINUX_T_UNKNOWN, /* 8 */ 143 13, /* 9 T_PROTFLT */ 144 1, /* 10 T_TRCTRAP */ 145 LINUX_T_UNKNOWN, /* 11 */ 146 14, /* 12 T_PAGEFLT */ 147 LINUX_T_UNKNOWN, /* 13 */ 148 17, /* 14 T_ALIGNFLT */ 149 LINUX_T_UNKNOWN, /* 15 */ 150 LINUX_T_UNKNOWN, /* 16 */ 151 LINUX_T_UNKNOWN, /* 17 */ 152 0, /* 18 T_DIVIDE */ 153 2, /* 19 T_NMI */ 154 4, /* 20 T_OFLOW */ 155 5, /* 21 T_BOUND */ 156 7, /* 22 T_DNA */ 157 8, /* 23 T_DOUBLEFLT */ 158 9, /* 24 T_FPOPFLT */ 159 10, /* 25 T_TSSFLT */ 160 11, /* 26 T_SEGNPFLT */ 161 12, /* 27 T_STKFLT */ 162 18, /* 28 T_MCHK */ 163 19, /* 29 T_XMMFLT */ 164 15 /* 30 T_RESERVED */ 165 }; 166 #define bsd_to_linux_trapcode(code) \ 167 ((code)<nitems(_bsd_to_linux_trapcode)? \ 168 _bsd_to_linux_trapcode[(code)]: \ 169 LINUX_T_UNKNOWN) 170 171 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 172 LINUX_VDSO_SYM_CHAR(linux_platform); 173 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 174 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 175 176 /* 177 * If FreeBSD & Linux have a difference of opinion about what a trap 178 * means, deal with it here. 179 * 180 * MPSAFE 181 */ 182 static int 183 linux_translate_traps(int signal, int trap_code) 184 { 185 186 if (signal != SIGBUS) 187 return (signal); 188 switch (trap_code) { 189 case T_PROTFLT: 190 case T_TSSFLT: 191 case T_DOUBLEFLT: 192 case T_PAGEFLT: 193 return (SIGSEGV); 194 default: 195 return (signal); 196 } 197 } 198 199 static int 200 linux_fetch_syscall_args(struct thread *td) 201 { 202 struct proc *p; 203 struct trapframe *frame; 204 struct syscall_args *sa; 205 206 p = td->td_proc; 207 frame = td->td_frame; 208 sa = &td->td_sa; 209 210 sa->args[0] = frame->tf_rdi; 211 sa->args[1] = frame->tf_rsi; 212 sa->args[2] = frame->tf_rdx; 213 sa->args[3] = frame->tf_rcx; 214 sa->args[4] = frame->tf_r8; 215 sa->args[5] = frame->tf_r9; 216 sa->code = frame->tf_rax; 217 sa->original_code = sa->code; 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]; 224 225 td->td_retval[0] = 0; 226 return (0); 227 } 228 229 static void 230 linux_set_syscall_retval(struct thread *td, int error) 231 { 232 struct trapframe *frame; 233 234 frame = td->td_frame; 235 236 switch (error) { 237 case 0: 238 frame->tf_rax = td->td_retval[0]; 239 frame->tf_r10 = frame->tf_rcx; 240 break; 241 242 case ERESTART: 243 /* 244 * Reconstruct pc, we know that 'syscall' is 2 bytes, 245 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 246 * We saved this in tf_err. 247 * 248 */ 249 frame->tf_rip -= frame->tf_err; 250 frame->tf_r10 = frame->tf_rcx; 251 break; 252 253 case EJUSTRETURN: 254 break; 255 256 default: 257 frame->tf_rax = bsd_to_linux_errno(error); 258 frame->tf_r10 = frame->tf_rcx; 259 break; 260 } 261 262 /* 263 * Differently from FreeBSD native ABI, on Linux only %rcx 264 * and %r11 values are not preserved across the syscall. 265 * Require full context restore to get all registers except 266 * those two restored at return to usermode. 267 * 268 * XXX: Would be great to be able to avoid PCB_FULL_IRET 269 * for the error == 0 case. 270 */ 271 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 272 } 273 274 static void 275 linux_set_fork_retval(struct thread *td) 276 { 277 struct trapframe *frame = td->td_frame; 278 279 frame->tf_rax = 0; 280 } 281 282 static int 283 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base) 284 { 285 Elf_Auxargs *args; 286 Elf_Auxinfo *argarray, *pos; 287 struct proc *p; 288 int error, issetugid; 289 290 p = imgp->proc; 291 args = (Elf64_Auxargs *)imgp->auxargs; 292 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 293 M_WAITOK | M_ZERO); 294 295 issetugid = p->p_flag & P_SUGID ? 1 : 0; 296 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 297 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 298 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 299 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 300 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 301 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 302 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 303 AUXARGS_ENTRY(pos, AT_BASE, args->base); 304 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 305 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 306 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 307 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 308 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 309 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 310 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 311 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary); 312 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0); 313 if (imgp->execpathp != 0) 314 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp); 315 if (args->execfd != -1) 316 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 317 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 318 AUXARGS_ENTRY(pos, AT_NULL, 0); 319 320 free(imgp->auxargs, M_TEMP); 321 imgp->auxargs = NULL; 322 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 323 324 error = copyout(argarray, (void *)base, 325 sizeof(*argarray) * LINUX_AT_COUNT); 326 free(argarray, M_TEMP); 327 return (error); 328 } 329 330 static int 331 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp) 332 { 333 Elf_Addr *base; 334 335 base = (Elf64_Addr *)*stack_base; 336 base--; 337 if (suword(base, (uint64_t)imgp->args->argc) == -1) 338 return (EFAULT); 339 340 *stack_base = (uintptr_t)base; 341 return (0); 342 } 343 344 /* 345 * Copy strings out to the new process address space, constructing new arg 346 * and env vector tables. Return a pointer to the base so that it can be used 347 * as the initial stack pointer. 348 */ 349 static int 350 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 351 { 352 int argc, envc, error; 353 char **vectp; 354 char *stringp; 355 uintptr_t destp, ustringp; 356 struct ps_strings *arginfo; 357 char canary[LINUX_AT_RANDOM_LEN]; 358 size_t execpath_len; 359 struct proc *p; 360 361 /* Calculate string base and vector table pointers. */ 362 if (imgp->execpath != NULL && imgp->auxargs != NULL) 363 execpath_len = strlen(imgp->execpath) + 1; 364 else 365 execpath_len = 0; 366 367 p = imgp->proc; 368 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings; 369 destp = (uintptr_t)arginfo; 370 371 if (execpath_len != 0) { 372 destp -= execpath_len; 373 destp = rounddown2(destp, sizeof(void *)); 374 imgp->execpathp = (void *)destp; 375 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 376 if (error != 0) 377 return (error); 378 } 379 380 /* Prepare the canary for SSP. */ 381 arc4rand(canary, sizeof(canary), 0); 382 destp -= roundup(sizeof(canary), sizeof(void *)); 383 imgp->canary = (void *)destp; 384 error = copyout(canary, imgp->canary, sizeof(canary)); 385 if (error != 0) 386 return (error); 387 388 /* Allocate room for the argument and environment strings. */ 389 destp -= ARG_MAX - imgp->args->stringspace; 390 destp = rounddown2(destp, sizeof(void *)); 391 ustringp = destp; 392 393 if (imgp->auxargs) { 394 /* 395 * Allocate room on the stack for the ELF auxargs 396 * array. It has LINUX_AT_COUNT entries. 397 */ 398 destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo); 399 destp = rounddown2(destp, sizeof(void *)); 400 } 401 402 vectp = (char **)destp; 403 404 /* 405 * Allocate room for the argv[] and env vectors including the 406 * terminating NULL pointers. 407 */ 408 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 409 410 /* 411 * Starting with 2.24, glibc depends on a 16-byte stack alignment. 412 * One "long argc" will be prepended later. 413 */ 414 vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8); 415 416 /* vectp also becomes our initial stack base. */ 417 *stack_base = (uintptr_t)vectp; 418 419 stringp = imgp->args->begin_argv; 420 argc = imgp->args->argc; 421 envc = imgp->args->envc; 422 423 /* Copy out strings - arguments and environment. */ 424 error = copyout(stringp, (void *)ustringp, 425 ARG_MAX - imgp->args->stringspace); 426 if (error != 0) 427 return (error); 428 429 /* Fill in "ps_strings" struct for ps, w, etc. */ 430 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 431 suword(&arginfo->ps_nargvstr, argc) != 0) 432 return (EFAULT); 433 434 /* Fill in argument portion of vector table. */ 435 for (; argc > 0; --argc) { 436 if (suword(vectp++, ustringp) != 0) 437 return (EFAULT); 438 while (*stringp++ != 0) 439 ustringp++; 440 ustringp++; 441 } 442 443 /* A null vector table pointer separates the argp's from the envp's. */ 444 if (suword(vectp++, 0) != 0) 445 return (EFAULT); 446 447 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 448 suword(&arginfo->ps_nenvstr, envc) != 0) 449 return (EFAULT); 450 451 /* Fill in environment portion of vector table. */ 452 for (; envc > 0; --envc) { 453 if (suword(vectp++, ustringp) != 0) 454 return (EFAULT); 455 while (*stringp++ != 0) 456 ustringp++; 457 ustringp++; 458 } 459 460 /* The end of the vector table is a null pointer. */ 461 if (suword(vectp, 0) != 0) 462 return (EFAULT); 463 464 if (imgp->auxargs) { 465 vectp++; 466 error = imgp->sysent->sv_copyout_auxargs(imgp, 467 (uintptr_t)vectp); 468 if (error != 0) 469 return (error); 470 } 471 472 return (0); 473 } 474 475 /* 476 * Reset registers to default values on exec. 477 */ 478 static void 479 linux_exec_setregs(struct thread *td, struct image_params *imgp, 480 uintptr_t stack) 481 { 482 struct trapframe *regs; 483 struct pcb *pcb; 484 register_t saved_rflags; 485 486 regs = td->td_frame; 487 pcb = td->td_pcb; 488 489 if (td->td_proc->p_md.md_ldt != NULL) 490 user_ldt_free(td); 491 492 pcb->pcb_fsbase = 0; 493 pcb->pcb_gsbase = 0; 494 clear_pcb_flags(pcb, PCB_32BIT); 495 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 496 set_pcb_flags(pcb, PCB_FULL_IRET); 497 498 saved_rflags = regs->tf_rflags & PSL_T; 499 bzero((char *)regs, sizeof(struct trapframe)); 500 regs->tf_rip = imgp->entry_addr; 501 regs->tf_rsp = stack; 502 regs->tf_rflags = PSL_USER | saved_rflags; 503 regs->tf_ss = _udatasel; 504 regs->tf_cs = _ucodesel; 505 regs->tf_ds = _udatasel; 506 regs->tf_es = _udatasel; 507 regs->tf_fs = _ufssel; 508 regs->tf_gs = _ugssel; 509 regs->tf_flags = TF_HASSEGS; 510 511 x86_clear_dbregs(pcb); 512 513 /* 514 * Drop the FP state if we hold it, so that the process gets a 515 * clean FP state if it uses the FPU again. 516 */ 517 fpstate_drop(td); 518 } 519 520 /* 521 * Copied from amd64/amd64/machdep.c 522 * 523 * XXX fpu state need? don't think so 524 */ 525 int 526 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 527 { 528 struct proc *p; 529 struct l_ucontext uc; 530 struct l_sigcontext *context; 531 struct trapframe *regs; 532 unsigned long rflags; 533 int error; 534 ksiginfo_t ksi; 535 536 regs = td->td_frame; 537 error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc)); 538 if (error != 0) 539 return (error); 540 541 p = td->td_proc; 542 context = &uc.uc_mcontext; 543 rflags = context->sc_rflags; 544 545 /* 546 * Don't allow users to change privileged or reserved flags. 547 */ 548 /* 549 * XXX do allow users to change the privileged flag PSL_RF. 550 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 551 * should sometimes set it there too. tf_rflags is kept in 552 * the signal context during signal handling and there is no 553 * other place to remember it, so the PSL_RF bit may be 554 * corrupted by the signal handler without us knowing. 555 * Corruption of the PSL_RF bit at worst causes one more or 556 * one less debugger trap, so allowing it is fairly harmless. 557 */ 558 559 #define RFLAG_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0) 560 if (!RFLAG_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 561 printf("linux_rt_sigreturn: rflags = 0x%lx\n", rflags); 562 return (EINVAL); 563 } 564 565 /* 566 * Don't allow users to load a valid privileged %cs. Let the 567 * hardware check for invalid selectors, excess privilege in 568 * other selectors, invalid %eip's and invalid %esp's. 569 */ 570 #define CS_SECURE(cs) (ISPL(cs) == SEL_UPL) 571 if (!CS_SECURE(context->sc_cs)) { 572 printf("linux_rt_sigreturn: cs = 0x%x\n", context->sc_cs); 573 ksiginfo_init_trap(&ksi); 574 ksi.ksi_signo = SIGBUS; 575 ksi.ksi_code = BUS_OBJERR; 576 ksi.ksi_trapno = T_PROTFLT; 577 ksi.ksi_addr = (void *)regs->tf_rip; 578 trapsignal(td, &ksi); 579 return (EINVAL); 580 } 581 582 PROC_LOCK(p); 583 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask); 584 SIG_CANTMASK(td->td_sigmask); 585 signotify(td); 586 PROC_UNLOCK(p); 587 588 regs->tf_rdi = context->sc_rdi; 589 regs->tf_rsi = context->sc_rsi; 590 regs->tf_rdx = context->sc_rdx; 591 regs->tf_rbp = context->sc_rbp; 592 regs->tf_rbx = context->sc_rbx; 593 regs->tf_rcx = context->sc_rcx; 594 regs->tf_rax = context->sc_rax; 595 regs->tf_rip = context->sc_rip; 596 regs->tf_rsp = context->sc_rsp; 597 regs->tf_r8 = context->sc_r8; 598 regs->tf_r9 = context->sc_r9; 599 regs->tf_r10 = context->sc_r10; 600 regs->tf_r11 = context->sc_r11; 601 regs->tf_r12 = context->sc_r12; 602 regs->tf_r13 = context->sc_r13; 603 regs->tf_r14 = context->sc_r14; 604 regs->tf_r15 = context->sc_r15; 605 regs->tf_cs = context->sc_cs; 606 regs->tf_err = context->sc_err; 607 regs->tf_rflags = rflags; 608 609 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 610 return (EJUSTRETURN); 611 } 612 613 /* 614 * copied from amd64/amd64/machdep.c 615 * 616 * Send an interrupt to process. 617 */ 618 static void 619 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 620 { 621 struct l_rt_sigframe sf, *sfp; 622 struct proc *p; 623 struct thread *td; 624 struct sigacts *psp; 625 caddr_t sp; 626 struct trapframe *regs; 627 int sig, code; 628 int oonstack; 629 630 td = curthread; 631 p = td->td_proc; 632 PROC_LOCK_ASSERT(p, MA_OWNED); 633 sig = ksi->ksi_signo; 634 psp = p->p_sigacts; 635 code = ksi->ksi_code; 636 mtx_assert(&psp->ps_mtx, MA_OWNED); 637 regs = td->td_frame; 638 oonstack = sigonstack(regs->tf_rsp); 639 640 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 641 catcher, sig, mask, code); 642 643 /* Save user context. */ 644 bzero(&sf, sizeof(sf)); 645 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask); 646 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask); 647 648 sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 649 sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 650 sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 651 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 652 653 sf.sf_sc.uc_mcontext.sc_rdi = regs->tf_rdi; 654 sf.sf_sc.uc_mcontext.sc_rsi = regs->tf_rsi; 655 sf.sf_sc.uc_mcontext.sc_rdx = regs->tf_rdx; 656 sf.sf_sc.uc_mcontext.sc_rbp = regs->tf_rbp; 657 sf.sf_sc.uc_mcontext.sc_rbx = regs->tf_rbx; 658 sf.sf_sc.uc_mcontext.sc_rcx = regs->tf_rcx; 659 sf.sf_sc.uc_mcontext.sc_rax = regs->tf_rax; 660 sf.sf_sc.uc_mcontext.sc_rip = regs->tf_rip; 661 sf.sf_sc.uc_mcontext.sc_rsp = regs->tf_rsp; 662 sf.sf_sc.uc_mcontext.sc_r8 = regs->tf_r8; 663 sf.sf_sc.uc_mcontext.sc_r9 = regs->tf_r9; 664 sf.sf_sc.uc_mcontext.sc_r10 = regs->tf_r10; 665 sf.sf_sc.uc_mcontext.sc_r11 = regs->tf_r11; 666 sf.sf_sc.uc_mcontext.sc_r12 = regs->tf_r12; 667 sf.sf_sc.uc_mcontext.sc_r13 = regs->tf_r13; 668 sf.sf_sc.uc_mcontext.sc_r14 = regs->tf_r14; 669 sf.sf_sc.uc_mcontext.sc_r15 = regs->tf_r15; 670 sf.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 671 sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags; 672 sf.sf_sc.uc_mcontext.sc_err = regs->tf_err; 673 sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 674 sf.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 675 676 /* Allocate space for the signal handler context. */ 677 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 678 SIGISMEMBER(psp->ps_sigonstack, sig)) { 679 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size - 680 sizeof(struct l_rt_sigframe); 681 } else 682 sp = (caddr_t)regs->tf_rsp - sizeof(struct l_rt_sigframe) - 128; 683 /* Align to 16 bytes. */ 684 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 685 686 /* Translate the signal. */ 687 sig = bsd_to_linux_signal(sig); 688 689 /* Build the argument list for the signal handler. */ 690 regs->tf_rdi = sig; /* arg 1 in %rdi */ 691 regs->tf_rax = 0; 692 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 693 regs->tf_rdx = (register_t)&sfp->sf_sc; /* arg 3 in %rdx */ 694 695 /* Fill in POSIX parts. */ 696 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 697 sf.sf_handler = catcher; 698 699 mtx_unlock(&psp->ps_mtx); 700 PROC_UNLOCK(p); 701 702 /* Copy the sigframe out to the user's stack. */ 703 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 704 PROC_LOCK(p); 705 sigexit(td, SIGILL); 706 } 707 708 regs->tf_rsp = (long)sfp; 709 regs->tf_rip = linux_rt_sigcode; 710 regs->tf_rflags &= ~(PSL_T | PSL_D); 711 regs->tf_cs = _ucodesel; 712 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 713 PROC_LOCK(p); 714 mtx_lock(&psp->ps_mtx); 715 } 716 717 #define LINUX_VSYSCALL_START (-10UL << 20) 718 #define LINUX_VSYSCALL_SZ 1024 719 720 const unsigned long linux_vsyscall_vector[] = { 721 LINUX_SYS_gettimeofday, 722 LINUX_SYS_linux_time, 723 LINUX_SYS_linux_getcpu, 724 }; 725 726 static int 727 linux_vsyscall(struct thread *td) 728 { 729 struct trapframe *frame; 730 uint64_t retqaddr; 731 int code, traced; 732 int error; 733 734 frame = td->td_frame; 735 736 /* Check %rip for vsyscall area. */ 737 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 738 return (EINVAL); 739 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 740 return (EINVAL); 741 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 742 if (code >= nitems(linux_vsyscall_vector)) 743 return (EINVAL); 744 745 /* 746 * vsyscall called as callq *(%rax), so we must 747 * use return address from %rsp and also fixup %rsp. 748 */ 749 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 750 if (error) 751 return (error); 752 753 frame->tf_rip = retqaddr; 754 frame->tf_rax = linux_vsyscall_vector[code]; 755 frame->tf_rsp += 8; 756 757 traced = (frame->tf_flags & PSL_T); 758 759 amd64_syscall(td, traced); 760 761 return (0); 762 } 763 764 struct sysentvec elf_linux_sysvec = { 765 .sv_size = LINUX_SYS_MAXSYSCALL, 766 .sv_table = linux_sysent, 767 .sv_transtrap = linux_translate_traps, 768 .sv_fixup = linux_fixup_elf, 769 .sv_sendsig = linux_rt_sendsig, 770 .sv_sigcode = &_binary_linux_vdso_so_o_start, 771 .sv_szsigcode = &linux_szsigcode, 772 .sv_name = "Linux ELF64", 773 .sv_coredump = elf64_coredump, 774 .sv_elf_core_osabi = ELFOSABI_NONE, 775 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 776 .sv_elf_core_prepare_notes = linux64_prepare_notes, 777 .sv_imgact_try = linux_exec_imgact_try, 778 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 779 .sv_minuser = VM_MIN_ADDRESS, 780 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 781 .sv_usrstack = LINUX_USRSTACK_LA48, 782 .sv_psstrings = LINUX_PS_STRINGS_LA48, 783 .sv_stackprot = VM_PROT_ALL, 784 .sv_copyout_auxargs = linux_copyout_auxargs, 785 .sv_copyout_strings = linux_copyout_strings, 786 .sv_setregs = linux_exec_setregs, 787 .sv_fixlimit = NULL, 788 .sv_maxssiz = NULL, 789 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 790 SV_SIG_WAITNDQ | SV_TIMEKEEP, 791 .sv_set_syscall_retval = linux_set_syscall_retval, 792 .sv_fetch_syscall_args = linux_fetch_syscall_args, 793 .sv_syscallnames = NULL, 794 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 795 .sv_shared_page_len = PAGE_SIZE, 796 .sv_schedtail = linux_schedtail, 797 .sv_thread_detach = linux_thread_detach, 798 .sv_trap = linux_vsyscall, 799 .sv_onexec = linux_on_exec_vmspace, 800 .sv_onexit = linux_on_exit, 801 .sv_ontdexit = linux_thread_dtor, 802 .sv_setid_allowed = &linux_setid_allowed_query, 803 .sv_set_fork_retval = linux_set_fork_retval, 804 }; 805 806 static int 807 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 808 { 809 int error; 810 811 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 812 LINUX_VDSOPAGE_SIZE, imgp); 813 if (error == 0) 814 linux_on_exec(p, imgp); 815 return (error); 816 } 817 818 /* 819 * linux_vdso_install() and linux_exec_sysvec_init() must be called 820 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 821 */ 822 static void 823 linux_exec_sysvec_init(void *param) 824 { 825 l_uintptr_t *ktimekeep_base, *ktsc_selector; 826 struct sysentvec *sv; 827 ptrdiff_t tkoff; 828 829 sv = param; 830 amd64_lower_shared_page(sv); 831 /* Fill timekeep_base */ 832 exec_sysvec_init(sv); 833 834 tkoff = kern_timekeep_base - linux_vdso_base; 835 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 836 *ktimekeep_base = sv->sv_timekeep_base; 837 838 tkoff = kern_tsc_selector - linux_vdso_base; 839 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 840 *ktsc_selector = linux_vdso_tsc_selector_idx(); 841 if (bootverbose) 842 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector); 843 } 844 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 845 linux_exec_sysvec_init, &elf_linux_sysvec); 846 847 static void 848 linux_vdso_install(const void *param) 849 { 850 char *vdso_start = &_binary_linux_vdso_so_o_start; 851 char *vdso_end = &_binary_linux_vdso_so_o_end; 852 853 linux_szsigcode = vdso_end - vdso_start; 854 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 855 856 linux_vdso_base = LINUX_VDSOPAGE_LA48; 857 if (hw_lower_amd64_sharedpage != 0) 858 linux_vdso_base -= PAGE_SIZE; 859 860 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 861 862 linux_vdso_obj = __elfN(linux_shared_page_init) 863 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 864 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 865 866 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 867 } 868 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 869 linux_vdso_install, NULL); 870 871 static void 872 linux_vdso_deinstall(const void *param) 873 { 874 875 __elfN(linux_shared_page_fini)(linux_vdso_obj, 876 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 877 } 878 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 879 linux_vdso_deinstall, NULL); 880 881 static void 882 linux_vdso_reloc(char *mapping, Elf_Addr offset) 883 { 884 const Elf_Ehdr *ehdr; 885 const Elf_Shdr *shdr; 886 Elf64_Addr *where, val; 887 Elf_Size rtype, symidx; 888 const Elf_Rela *rela; 889 Elf_Addr addr, addend; 890 int relacnt; 891 int i, j; 892 893 MPASS(offset != 0); 894 895 relacnt = 0; 896 ehdr = (const Elf_Ehdr *)mapping; 897 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 898 for (i = 0; i < ehdr->e_shnum; i++) 899 { 900 switch (shdr[i].sh_type) { 901 case SHT_REL: 902 printf("Linux x86_64 vDSO: unexpected Rel section\n"); 903 break; 904 case SHT_RELA: 905 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset); 906 relacnt = shdr[i].sh_size / sizeof(*rela); 907 } 908 } 909 910 for (j = 0; j < relacnt; j++, rela++) { 911 where = (Elf_Addr *)(mapping + rela->r_offset); 912 addend = rela->r_addend; 913 rtype = ELF_R_TYPE(rela->r_info); 914 symidx = ELF_R_SYM(rela->r_info); 915 916 switch (rtype) { 917 case R_X86_64_NONE: /* none */ 918 break; 919 920 case R_X86_64_RELATIVE: /* B + A */ 921 addr = (Elf_Addr)(offset + addend); 922 val = addr; 923 if (*where != val) 924 *where = val; 925 break; 926 case R_X86_64_IRELATIVE: 927 printf("Linux x86_64 vDSO: unexpected ifunc relocation, " 928 "symbol index %ld\n", symidx); 929 break; 930 default: 931 printf("Linux x86_64 vDSO: unexpected relocation type %ld, " 932 "symbol index %ld\n", rtype, symidx); 933 } 934 } 935 } 936 937 static char GNULINUX_ABI_VENDOR[] = "GNU"; 938 static int GNULINUX_ABI_DESC = 0; 939 940 static bool 941 linux_trans_osrel(const Elf_Note *note, int32_t *osrel) 942 { 943 const Elf32_Word *desc; 944 uintptr_t p; 945 946 p = (uintptr_t)(note + 1); 947 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 948 949 desc = (const Elf32_Word *)p; 950 if (desc[0] != GNULINUX_ABI_DESC) 951 return (false); 952 953 /* 954 * For Linux we encode osrel using the Linux convention of 955 * (version << 16) | (major << 8) | (minor) 956 * See macro in linux_mib.h 957 */ 958 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]); 959 960 return (true); 961 } 962 963 static Elf_Brandnote linux64_brandnote = { 964 .hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR), 965 .hdr.n_descsz = 16, 966 .hdr.n_type = 1, 967 .vendor = GNULINUX_ABI_VENDOR, 968 .flags = BN_TRANSLATE_OSREL, 969 .trans_osrel = linux_trans_osrel 970 }; 971 972 static Elf64_Brandinfo linux_glibc2brand = { 973 .brand = ELFOSABI_LINUX, 974 .machine = EM_X86_64, 975 .compat_3_brand = "Linux", 976 .emul_path = linux_emul_path, 977 .interp_path = "/lib64/ld-linux-x86-64.so.2", 978 .sysvec = &elf_linux_sysvec, 979 .interp_newpath = NULL, 980 .brand_note = &linux64_brandnote, 981 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 982 }; 983 984 static Elf64_Brandinfo linux_glibc2brandshort = { 985 .brand = ELFOSABI_LINUX, 986 .machine = EM_X86_64, 987 .compat_3_brand = "Linux", 988 .emul_path = linux_emul_path, 989 .interp_path = "/lib64/ld-linux.so.2", 990 .sysvec = &elf_linux_sysvec, 991 .interp_newpath = NULL, 992 .brand_note = &linux64_brandnote, 993 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 994 }; 995 996 static Elf64_Brandinfo linux_muslbrand = { 997 .brand = ELFOSABI_LINUX, 998 .machine = EM_X86_64, 999 .compat_3_brand = "Linux", 1000 .emul_path = linux_emul_path, 1001 .interp_path = "/lib/ld-musl-x86_64.so.1", 1002 .sysvec = &elf_linux_sysvec, 1003 .interp_newpath = NULL, 1004 .brand_note = &linux64_brandnote, 1005 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 1006 LINUX_BI_FUTEX_REQUEUE 1007 }; 1008 1009 Elf64_Brandinfo *linux_brandlist[] = { 1010 &linux_glibc2brand, 1011 &linux_glibc2brandshort, 1012 &linux_muslbrand, 1013 NULL 1014 }; 1015 1016 static int 1017 linux64_elf_modevent(module_t mod, int type, void *data) 1018 { 1019 Elf64_Brandinfo **brandinfo; 1020 int error; 1021 struct linux_ioctl_handler **lihp; 1022 1023 error = 0; 1024 1025 switch(type) { 1026 case MOD_LOAD: 1027 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1028 ++brandinfo) 1029 if (elf64_insert_brand_entry(*brandinfo) < 0) 1030 error = EINVAL; 1031 if (error == 0) { 1032 SET_FOREACH(lihp, linux_ioctl_handler_set) 1033 linux_ioctl_register_handler(*lihp); 1034 stclohz = (stathz ? stathz : hz); 1035 if (bootverbose) 1036 printf("Linux x86-64 ELF exec handler installed\n"); 1037 } else 1038 printf("cannot insert Linux x86-64 ELF brand handler\n"); 1039 break; 1040 case MOD_UNLOAD: 1041 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1042 ++brandinfo) 1043 if (elf64_brand_inuse(*brandinfo)) 1044 error = EBUSY; 1045 if (error == 0) { 1046 for (brandinfo = &linux_brandlist[0]; 1047 *brandinfo != NULL; ++brandinfo) 1048 if (elf64_remove_brand_entry(*brandinfo) < 0) 1049 error = EINVAL; 1050 } 1051 if (error == 0) { 1052 SET_FOREACH(lihp, linux_ioctl_handler_set) 1053 linux_ioctl_unregister_handler(*lihp); 1054 if (bootverbose) 1055 printf("Linux x86_64 ELF exec handler removed\n"); 1056 } else 1057 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n"); 1058 break; 1059 default: 1060 return (EOPNOTSUPP); 1061 } 1062 return (error); 1063 } 1064 1065 static moduledata_t linux64_elf_mod = { 1066 "linux64elf", 1067 linux64_elf_modevent, 1068 0 1069 }; 1070 1071 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1072 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 1073 FEATURE(linux64, "Linux 64bit support"); 1074