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 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 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 sa->original_code = sa->code; 219 220 if (sa->code >= p->p_sysent->sv_size) 221 /* nosys */ 222 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 223 else 224 sa->callp = &p->p_sysent->sv_table[sa->code]; 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; 234 235 frame = td->td_frame; 236 237 switch (error) { 238 case 0: 239 frame->tf_rax = td->td_retval[0]; 240 frame->tf_r10 = frame->tf_rcx; 241 break; 242 243 case ERESTART: 244 /* 245 * Reconstruct pc, we know that 'syscall' is 2 bytes, 246 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 247 * We saved this in tf_err. 248 * 249 */ 250 frame->tf_rip -= frame->tf_err; 251 frame->tf_r10 = frame->tf_rcx; 252 break; 253 254 case EJUSTRETURN: 255 break; 256 257 default: 258 frame->tf_rax = bsd_to_linux_errno(error); 259 frame->tf_r10 = frame->tf_rcx; 260 break; 261 } 262 263 /* 264 * Differently from FreeBSD native ABI, on Linux only %rcx 265 * and %r11 values are not preserved across the syscall. 266 * Require full context restore to get all registers except 267 * those two restored at return to usermode. 268 * 269 * XXX: Would be great to be able to avoid PCB_FULL_IRET 270 * for the error == 0 case. 271 */ 272 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 273 } 274 275 static void 276 linux_set_fork_retval(struct thread *td) 277 { 278 struct trapframe *frame = td->td_frame; 279 280 frame->tf_rax = 0; 281 } 282 283 static int 284 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base) 285 { 286 Elf_Auxargs *args; 287 Elf_Auxinfo *argarray, *pos; 288 struct proc *p; 289 int error, issetugid; 290 291 p = imgp->proc; 292 args = (Elf64_Auxargs *)imgp->auxargs; 293 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 294 M_WAITOK | M_ZERO); 295 296 issetugid = p->p_flag & P_SUGID ? 1 : 0; 297 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 298 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 299 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 300 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 301 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 302 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 303 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 304 AUXARGS_ENTRY(pos, AT_BASE, args->base); 305 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 306 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 307 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 308 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 309 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 310 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 311 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 312 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary); 313 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0); 314 if (imgp->execpathp != 0) 315 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp); 316 if (args->execfd != -1) 317 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 318 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 319 AUXARGS_ENTRY(pos, AT_NULL, 0); 320 321 free(imgp->auxargs, M_TEMP); 322 imgp->auxargs = NULL; 323 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 324 325 error = copyout(argarray, (void *)base, 326 sizeof(*argarray) * LINUX_AT_COUNT); 327 free(argarray, M_TEMP); 328 return (error); 329 } 330 331 static int 332 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp) 333 { 334 Elf_Addr *base; 335 336 base = (Elf64_Addr *)*stack_base; 337 base--; 338 if (suword(base, (uint64_t)imgp->args->argc) == -1) 339 return (EFAULT); 340 341 *stack_base = (uintptr_t)base; 342 return (0); 343 } 344 345 /* 346 * Copy strings out to the new process address space, constructing new arg 347 * and env vector tables. Return a pointer to the base so that it can be used 348 * as the initial stack pointer. 349 */ 350 static int 351 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 352 { 353 int argc, envc, error; 354 char **vectp; 355 char *stringp; 356 uintptr_t destp, ustringp; 357 struct ps_strings *arginfo; 358 char canary[LINUX_AT_RANDOM_LEN]; 359 size_t execpath_len; 360 struct proc *p; 361 362 p = imgp->proc; 363 arginfo = (struct ps_strings *)PROC_PS_STRINGS(p); 364 destp = (uintptr_t)arginfo; 365 366 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 367 execpath_len = strlen(imgp->execpath) + 1; 368 destp -= execpath_len; 369 destp = rounddown2(destp, sizeof(void *)); 370 imgp->execpathp = (void *)destp; 371 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 372 if (error != 0) 373 return (error); 374 } 375 376 /* Prepare the canary for SSP. */ 377 arc4rand(canary, sizeof(canary), 0); 378 destp -= roundup(sizeof(canary), sizeof(void *)); 379 imgp->canary = (void *)destp; 380 error = copyout(canary, imgp->canary, sizeof(canary)); 381 if (error != 0) 382 return (error); 383 384 /* Allocate room for the argument and environment strings. */ 385 destp -= ARG_MAX - imgp->args->stringspace; 386 destp = rounddown2(destp, sizeof(void *)); 387 ustringp = destp; 388 389 if (imgp->auxargs) { 390 /* 391 * Allocate room on the stack for the ELF auxargs 392 * array. It has LINUX_AT_COUNT entries. 393 */ 394 destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo); 395 destp = rounddown2(destp, sizeof(void *)); 396 } 397 398 vectp = (char **)destp; 399 400 /* 401 * Allocate room for the argv[] and env vectors including the 402 * terminating NULL pointers. 403 */ 404 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 405 406 /* 407 * Starting with 2.24, glibc depends on a 16-byte stack alignment. 408 * One "long argc" will be prepended later. 409 */ 410 vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8); 411 412 /* vectp also becomes our initial stack base. */ 413 *stack_base = (uintptr_t)vectp; 414 415 stringp = imgp->args->begin_argv; 416 argc = imgp->args->argc; 417 envc = imgp->args->envc; 418 419 /* Copy out strings - arguments and environment. */ 420 error = copyout(stringp, (void *)ustringp, 421 ARG_MAX - imgp->args->stringspace); 422 if (error != 0) 423 return (error); 424 425 /* Fill in "ps_strings" struct for ps, w, etc. */ 426 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 427 suword(&arginfo->ps_nargvstr, argc) != 0) 428 return (EFAULT); 429 430 /* Fill in argument portion of vector table. */ 431 for (; argc > 0; --argc) { 432 if (suword(vectp++, ustringp) != 0) 433 return (EFAULT); 434 while (*stringp++ != 0) 435 ustringp++; 436 ustringp++; 437 } 438 439 /* A null vector table pointer separates the argp's from the envp's. */ 440 if (suword(vectp++, 0) != 0) 441 return (EFAULT); 442 443 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 444 suword(&arginfo->ps_nenvstr, envc) != 0) 445 return (EFAULT); 446 447 /* Fill in environment portion of vector table. */ 448 for (; envc > 0; --envc) { 449 if (suword(vectp++, ustringp) != 0) 450 return (EFAULT); 451 while (*stringp++ != 0) 452 ustringp++; 453 ustringp++; 454 } 455 456 /* The end of the vector table is a null pointer. */ 457 if (suword(vectp, 0) != 0) 458 return (EFAULT); 459 460 if (imgp->auxargs) { 461 vectp++; 462 error = imgp->sysent->sv_copyout_auxargs(imgp, 463 (uintptr_t)vectp); 464 if (error != 0) 465 return (error); 466 } 467 468 return (0); 469 } 470 471 /* 472 * Reset registers to default values on exec. 473 */ 474 static void 475 linux_exec_setregs(struct thread *td, struct image_params *imgp, 476 uintptr_t stack) 477 { 478 struct trapframe *regs; 479 struct pcb *pcb; 480 register_t saved_rflags; 481 482 regs = td->td_frame; 483 pcb = td->td_pcb; 484 485 if (td->td_proc->p_md.md_ldt != NULL) 486 user_ldt_free(td); 487 488 pcb->pcb_fsbase = 0; 489 pcb->pcb_gsbase = 0; 490 clear_pcb_flags(pcb, PCB_32BIT); 491 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 492 set_pcb_flags(pcb, PCB_FULL_IRET); 493 494 saved_rflags = regs->tf_rflags & PSL_T; 495 bzero((char *)regs, sizeof(struct trapframe)); 496 regs->tf_rip = imgp->entry_addr; 497 regs->tf_rsp = stack; 498 regs->tf_rflags = PSL_USER | saved_rflags; 499 regs->tf_ss = _udatasel; 500 regs->tf_cs = _ucodesel; 501 regs->tf_ds = _udatasel; 502 regs->tf_es = _udatasel; 503 regs->tf_fs = _ufssel; 504 regs->tf_gs = _ugssel; 505 regs->tf_flags = TF_HASSEGS; 506 507 x86_clear_dbregs(pcb); 508 509 /* 510 * Drop the FP state if we hold it, so that the process gets a 511 * clean FP state if it uses the FPU again. 512 */ 513 fpstate_drop(td); 514 } 515 516 /* 517 * Copied from amd64/amd64/machdep.c 518 * 519 * XXX fpu state need? don't think so 520 */ 521 int 522 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 523 { 524 struct proc *p; 525 struct l_ucontext uc; 526 struct l_sigcontext *context; 527 struct trapframe *regs; 528 unsigned long rflags; 529 int error; 530 ksiginfo_t ksi; 531 532 regs = td->td_frame; 533 error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc)); 534 if (error != 0) 535 return (error); 536 537 p = td->td_proc; 538 context = &uc.uc_mcontext; 539 rflags = context->sc_rflags; 540 541 /* 542 * Don't allow users to change privileged or reserved flags. 543 */ 544 /* 545 * XXX do allow users to change the privileged flag PSL_RF. 546 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 547 * should sometimes set it there too. tf_rflags is kept in 548 * the signal context during signal handling and there is no 549 * other place to remember it, so the PSL_RF bit may be 550 * corrupted by the signal handler without us knowing. 551 * Corruption of the PSL_RF bit at worst causes one more or 552 * one less debugger trap, so allowing it is fairly harmless. 553 */ 554 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 555 uprintf("pid %d comm %s linux mangled rflags %#lx\n", 556 p->p_pid, p->p_comm, rflags); 557 return (EINVAL); 558 } 559 560 /* 561 * Don't allow users to load a valid privileged %cs. Let the 562 * hardware check for invalid selectors, excess privilege in 563 * other selectors, invalid %eip's and invalid %esp's. 564 */ 565 if (!CS_SECURE(context->sc_cs)) { 566 uprintf("pid %d comm %s linux mangled cs %#x\n", 567 p->p_pid, p->p_comm, context->sc_cs); 568 ksiginfo_init_trap(&ksi); 569 ksi.ksi_signo = SIGBUS; 570 ksi.ksi_code = BUS_OBJERR; 571 ksi.ksi_trapno = T_PROTFLT; 572 ksi.ksi_addr = (void *)regs->tf_rip; 573 trapsignal(td, &ksi); 574 return (EINVAL); 575 } 576 577 PROC_LOCK(p); 578 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask); 579 SIG_CANTMASK(td->td_sigmask); 580 signotify(td); 581 PROC_UNLOCK(p); 582 583 regs->tf_rdi = context->sc_rdi; 584 regs->tf_rsi = context->sc_rsi; 585 regs->tf_rdx = context->sc_rdx; 586 regs->tf_rbp = context->sc_rbp; 587 regs->tf_rbx = context->sc_rbx; 588 regs->tf_rcx = context->sc_rcx; 589 regs->tf_rax = context->sc_rax; 590 regs->tf_rip = context->sc_rip; 591 regs->tf_rsp = context->sc_rsp; 592 regs->tf_r8 = context->sc_r8; 593 regs->tf_r9 = context->sc_r9; 594 regs->tf_r10 = context->sc_r10; 595 regs->tf_r11 = context->sc_r11; 596 regs->tf_r12 = context->sc_r12; 597 regs->tf_r13 = context->sc_r13; 598 regs->tf_r14 = context->sc_r14; 599 regs->tf_r15 = context->sc_r15; 600 regs->tf_cs = context->sc_cs; 601 regs->tf_err = context->sc_err; 602 regs->tf_rflags = rflags; 603 604 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 605 return (EJUSTRETURN); 606 } 607 608 /* 609 * copied from amd64/amd64/machdep.c 610 * 611 * Send an interrupt to process. 612 */ 613 static void 614 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 615 { 616 struct l_rt_sigframe sf, *sfp; 617 struct proc *p; 618 struct thread *td; 619 struct sigacts *psp; 620 caddr_t sp; 621 struct trapframe *regs; 622 int sig, code; 623 int oonstack; 624 625 td = curthread; 626 p = td->td_proc; 627 PROC_LOCK_ASSERT(p, MA_OWNED); 628 sig = ksi->ksi_signo; 629 psp = p->p_sigacts; 630 code = ksi->ksi_code; 631 mtx_assert(&psp->ps_mtx, MA_OWNED); 632 regs = td->td_frame; 633 oonstack = sigonstack(regs->tf_rsp); 634 635 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 636 catcher, sig, mask, code); 637 638 /* Save user context. */ 639 bzero(&sf, sizeof(sf)); 640 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_sigmask); 641 bsd_to_linux_sigset(mask, &sf.sf_sc.uc_mcontext.sc_mask); 642 643 sf.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 644 sf.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size; 645 sf.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 646 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 647 648 sf.sf_sc.uc_mcontext.sc_rdi = regs->tf_rdi; 649 sf.sf_sc.uc_mcontext.sc_rsi = regs->tf_rsi; 650 sf.sf_sc.uc_mcontext.sc_rdx = regs->tf_rdx; 651 sf.sf_sc.uc_mcontext.sc_rbp = regs->tf_rbp; 652 sf.sf_sc.uc_mcontext.sc_rbx = regs->tf_rbx; 653 sf.sf_sc.uc_mcontext.sc_rcx = regs->tf_rcx; 654 sf.sf_sc.uc_mcontext.sc_rax = regs->tf_rax; 655 sf.sf_sc.uc_mcontext.sc_rip = regs->tf_rip; 656 sf.sf_sc.uc_mcontext.sc_rsp = regs->tf_rsp; 657 sf.sf_sc.uc_mcontext.sc_r8 = regs->tf_r8; 658 sf.sf_sc.uc_mcontext.sc_r9 = regs->tf_r9; 659 sf.sf_sc.uc_mcontext.sc_r10 = regs->tf_r10; 660 sf.sf_sc.uc_mcontext.sc_r11 = regs->tf_r11; 661 sf.sf_sc.uc_mcontext.sc_r12 = regs->tf_r12; 662 sf.sf_sc.uc_mcontext.sc_r13 = regs->tf_r13; 663 sf.sf_sc.uc_mcontext.sc_r14 = regs->tf_r14; 664 sf.sf_sc.uc_mcontext.sc_r15 = regs->tf_r15; 665 sf.sf_sc.uc_mcontext.sc_cs = regs->tf_cs; 666 sf.sf_sc.uc_mcontext.sc_rflags = regs->tf_rflags; 667 sf.sf_sc.uc_mcontext.sc_err = regs->tf_err; 668 sf.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 669 sf.sf_sc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 670 671 /* Allocate space for the signal handler context. */ 672 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 673 SIGISMEMBER(psp->ps_sigonstack, sig)) { 674 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size; 675 } else 676 sp = (caddr_t)regs->tf_rsp - 128; 677 sp -= sizeof(struct l_rt_sigframe); 678 /* Align to 16 bytes. */ 679 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 680 681 /* Translate the signal. */ 682 sig = bsd_to_linux_signal(sig); 683 684 /* Build the argument list for the signal handler. */ 685 regs->tf_rdi = sig; /* arg 1 in %rdi */ 686 regs->tf_rax = 0; 687 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 688 regs->tf_rdx = (register_t)&sfp->sf_sc; /* arg 3 in %rdx */ 689 690 /* Fill in POSIX parts. */ 691 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 692 sf.sf_handler = catcher; 693 694 mtx_unlock(&psp->ps_mtx); 695 PROC_UNLOCK(p); 696 697 /* Copy the sigframe out to the user's stack. */ 698 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 699 uprintf("pid %d comm %s has trashed its stack, killing\n", 700 p->p_pid, p->p_comm); 701 PROC_LOCK(p); 702 sigexit(td, SIGILL); 703 } 704 705 regs->tf_rsp = (long)sfp; 706 regs->tf_rip = linux_rt_sigcode; 707 regs->tf_rflags &= ~(PSL_T | PSL_D); 708 regs->tf_cs = _ucodesel; 709 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 710 PROC_LOCK(p); 711 mtx_lock(&psp->ps_mtx); 712 } 713 714 #define LINUX_VSYSCALL_START (-10UL << 20) 715 #define LINUX_VSYSCALL_SZ 1024 716 717 const unsigned long linux_vsyscall_vector[] = { 718 LINUX_SYS_gettimeofday, 719 LINUX_SYS_linux_time, 720 LINUX_SYS_linux_getcpu, 721 }; 722 723 static int 724 linux_vsyscall(struct thread *td) 725 { 726 struct trapframe *frame; 727 uint64_t retqaddr; 728 int code, traced; 729 int error; 730 731 frame = td->td_frame; 732 733 /* Check %rip for vsyscall area. */ 734 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 735 return (EINVAL); 736 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 737 return (EINVAL); 738 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 739 if (code >= nitems(linux_vsyscall_vector)) 740 return (EINVAL); 741 742 /* 743 * vsyscall called as callq *(%rax), so we must 744 * use return address from %rsp and also fixup %rsp. 745 */ 746 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 747 if (error) 748 return (error); 749 750 frame->tf_rip = retqaddr; 751 frame->tf_rax = linux_vsyscall_vector[code]; 752 frame->tf_rsp += 8; 753 754 traced = (frame->tf_flags & PSL_T); 755 756 amd64_syscall(td, traced); 757 758 return (0); 759 } 760 761 struct sysentvec elf_linux_sysvec = { 762 .sv_size = LINUX_SYS_MAXSYSCALL, 763 .sv_table = linux_sysent, 764 .sv_transtrap = linux_translate_traps, 765 .sv_fixup = linux_fixup_elf, 766 .sv_sendsig = linux_rt_sendsig, 767 .sv_sigcode = &_binary_linux_vdso_so_o_start, 768 .sv_szsigcode = &linux_szsigcode, 769 .sv_name = "Linux ELF64", 770 .sv_coredump = elf64_coredump, 771 .sv_elf_core_osabi = ELFOSABI_NONE, 772 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 773 .sv_elf_core_prepare_notes = linux64_prepare_notes, 774 .sv_imgact_try = linux_exec_imgact_try, 775 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 776 .sv_minuser = VM_MIN_ADDRESS, 777 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 778 .sv_usrstack = LINUX_USRSTACK_LA48, 779 .sv_psstrings = LINUX_PS_STRINGS_LA48, 780 .sv_psstringssz = sizeof(struct ps_strings), 781 .sv_stackprot = VM_PROT_ALL, 782 .sv_copyout_auxargs = linux_copyout_auxargs, 783 .sv_copyout_strings = linux_copyout_strings, 784 .sv_setregs = linux_exec_setregs, 785 .sv_fixlimit = NULL, 786 .sv_maxssiz = NULL, 787 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 788 SV_SIG_WAITNDQ | SV_TIMEKEEP, 789 .sv_set_syscall_retval = linux_set_syscall_retval, 790 .sv_fetch_syscall_args = linux_fetch_syscall_args, 791 .sv_syscallnames = NULL, 792 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 793 .sv_shared_page_len = PAGE_SIZE, 794 .sv_schedtail = linux_schedtail, 795 .sv_thread_detach = linux_thread_detach, 796 .sv_trap = linux_vsyscall, 797 .sv_onexec = linux_on_exec_vmspace, 798 .sv_onexit = linux_on_exit, 799 .sv_ontdexit = linux_thread_dtor, 800 .sv_setid_allowed = &linux_setid_allowed_query, 801 .sv_set_fork_retval = linux_set_fork_retval, 802 }; 803 804 static int 805 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 806 { 807 int error; 808 809 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 810 LINUX_VDSOPAGE_SIZE, imgp); 811 if (error == 0) 812 linux_on_exec(p, imgp); 813 return (error); 814 } 815 816 /* 817 * linux_vdso_install() and linux_exec_sysvec_init() must be called 818 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 819 */ 820 static void 821 linux_exec_sysvec_init(void *param) 822 { 823 l_uintptr_t *ktimekeep_base, *ktsc_selector; 824 struct sysentvec *sv; 825 ptrdiff_t tkoff; 826 827 sv = param; 828 amd64_lower_shared_page(sv); 829 /* Fill timekeep_base */ 830 exec_sysvec_init(sv); 831 832 tkoff = kern_timekeep_base - linux_vdso_base; 833 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 834 *ktimekeep_base = sv->sv_timekeep_base; 835 836 tkoff = kern_tsc_selector - linux_vdso_base; 837 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 838 *ktsc_selector = linux_vdso_tsc_selector_idx(); 839 if (bootverbose) 840 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector); 841 842 tkoff = kern_cpu_selector - linux_vdso_base; 843 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 844 *ktsc_selector = linux_vdso_cpu_selector_idx(); 845 if (bootverbose) 846 printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector); 847 } 848 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 849 linux_exec_sysvec_init, &elf_linux_sysvec); 850 851 static void 852 linux_vdso_install(const void *param) 853 { 854 char *vdso_start = &_binary_linux_vdso_so_o_start; 855 char *vdso_end = &_binary_linux_vdso_so_o_end; 856 857 linux_szsigcode = vdso_end - vdso_start; 858 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 859 860 linux_vdso_base = LINUX_VDSOPAGE_LA48; 861 if (hw_lower_amd64_sharedpage != 0) 862 linux_vdso_base -= PAGE_SIZE; 863 864 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 865 866 linux_vdso_obj = __elfN(linux_shared_page_init) 867 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 868 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 869 870 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 871 } 872 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 873 linux_vdso_install, NULL); 874 875 static void 876 linux_vdso_deinstall(const void *param) 877 { 878 879 __elfN(linux_shared_page_fini)(linux_vdso_obj, 880 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 881 } 882 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 883 linux_vdso_deinstall, NULL); 884 885 static void 886 linux_vdso_reloc(char *mapping, Elf_Addr offset) 887 { 888 const Elf_Ehdr *ehdr; 889 const Elf_Shdr *shdr; 890 Elf64_Addr *where, val; 891 Elf_Size rtype, symidx; 892 const Elf_Rela *rela; 893 Elf_Addr addr, addend; 894 int relacnt; 895 int i, j; 896 897 MPASS(offset != 0); 898 899 relacnt = 0; 900 ehdr = (const Elf_Ehdr *)mapping; 901 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 902 for (i = 0; i < ehdr->e_shnum; i++) 903 { 904 switch (shdr[i].sh_type) { 905 case SHT_REL: 906 printf("Linux x86_64 vDSO: unexpected Rel section\n"); 907 break; 908 case SHT_RELA: 909 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset); 910 relacnt = shdr[i].sh_size / sizeof(*rela); 911 } 912 } 913 914 for (j = 0; j < relacnt; j++, rela++) { 915 where = (Elf_Addr *)(mapping + rela->r_offset); 916 addend = rela->r_addend; 917 rtype = ELF_R_TYPE(rela->r_info); 918 symidx = ELF_R_SYM(rela->r_info); 919 920 switch (rtype) { 921 case R_X86_64_NONE: /* none */ 922 break; 923 924 case R_X86_64_RELATIVE: /* B + A */ 925 addr = (Elf_Addr)(offset + addend); 926 val = addr; 927 if (*where != val) 928 *where = val; 929 break; 930 case R_X86_64_IRELATIVE: 931 printf("Linux x86_64 vDSO: unexpected ifunc relocation, " 932 "symbol index %ld\n", symidx); 933 break; 934 default: 935 printf("Linux x86_64 vDSO: unexpected relocation type %ld, " 936 "symbol index %ld\n", rtype, symidx); 937 } 938 } 939 } 940 941 static char GNULINUX_ABI_VENDOR[] = "GNU"; 942 static int GNULINUX_ABI_DESC = 0; 943 944 static bool 945 linux_trans_osrel(const Elf_Note *note, int32_t *osrel) 946 { 947 const Elf32_Word *desc; 948 uintptr_t p; 949 950 p = (uintptr_t)(note + 1); 951 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 952 953 desc = (const Elf32_Word *)p; 954 if (desc[0] != GNULINUX_ABI_DESC) 955 return (false); 956 957 /* 958 * For Linux we encode osrel using the Linux convention of 959 * (version << 16) | (major << 8) | (minor) 960 * See macro in linux_mib.h 961 */ 962 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]); 963 964 return (true); 965 } 966 967 static Elf_Brandnote linux64_brandnote = { 968 .hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR), 969 .hdr.n_descsz = 16, 970 .hdr.n_type = 1, 971 .vendor = GNULINUX_ABI_VENDOR, 972 .flags = BN_TRANSLATE_OSREL, 973 .trans_osrel = linux_trans_osrel 974 }; 975 976 static Elf64_Brandinfo linux_glibc2brand = { 977 .brand = ELFOSABI_LINUX, 978 .machine = EM_X86_64, 979 .compat_3_brand = "Linux", 980 .emul_path = linux_emul_path, 981 .interp_path = "/lib64/ld-linux-x86-64.so.2", 982 .sysvec = &elf_linux_sysvec, 983 .interp_newpath = NULL, 984 .brand_note = &linux64_brandnote, 985 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 986 }; 987 988 static Elf64_Brandinfo linux_glibc2brandshort = { 989 .brand = ELFOSABI_LINUX, 990 .machine = EM_X86_64, 991 .compat_3_brand = "Linux", 992 .emul_path = linux_emul_path, 993 .interp_path = "/lib64/ld-linux.so.2", 994 .sysvec = &elf_linux_sysvec, 995 .interp_newpath = NULL, 996 .brand_note = &linux64_brandnote, 997 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 998 }; 999 1000 static Elf64_Brandinfo linux_muslbrand = { 1001 .brand = ELFOSABI_LINUX, 1002 .machine = EM_X86_64, 1003 .compat_3_brand = "Linux", 1004 .emul_path = linux_emul_path, 1005 .interp_path = "/lib/ld-musl-x86_64.so.1", 1006 .sysvec = &elf_linux_sysvec, 1007 .interp_newpath = NULL, 1008 .brand_note = &linux64_brandnote, 1009 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 1010 LINUX_BI_FUTEX_REQUEUE 1011 }; 1012 1013 Elf64_Brandinfo *linux_brandlist[] = { 1014 &linux_glibc2brand, 1015 &linux_glibc2brandshort, 1016 &linux_muslbrand, 1017 NULL 1018 }; 1019 1020 static int 1021 linux64_elf_modevent(module_t mod, int type, void *data) 1022 { 1023 Elf64_Brandinfo **brandinfo; 1024 int error; 1025 struct linux_ioctl_handler **lihp; 1026 1027 error = 0; 1028 1029 switch(type) { 1030 case MOD_LOAD: 1031 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1032 ++brandinfo) 1033 if (elf64_insert_brand_entry(*brandinfo) < 0) 1034 error = EINVAL; 1035 if (error == 0) { 1036 SET_FOREACH(lihp, linux_ioctl_handler_set) 1037 linux_ioctl_register_handler(*lihp); 1038 stclohz = (stathz ? stathz : hz); 1039 if (bootverbose) 1040 printf("Linux x86-64 ELF exec handler installed\n"); 1041 } else 1042 printf("cannot insert Linux x86-64 ELF brand handler\n"); 1043 break; 1044 case MOD_UNLOAD: 1045 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1046 ++brandinfo) 1047 if (elf64_brand_inuse(*brandinfo)) 1048 error = EBUSY; 1049 if (error == 0) { 1050 for (brandinfo = &linux_brandlist[0]; 1051 *brandinfo != NULL; ++brandinfo) 1052 if (elf64_remove_brand_entry(*brandinfo) < 0) 1053 error = EINVAL; 1054 } 1055 if (error == 0) { 1056 SET_FOREACH(lihp, linux_ioctl_handler_set) 1057 linux_ioctl_unregister_handler(*lihp); 1058 if (bootverbose) 1059 printf("Linux x86_64 ELF exec handler removed\n"); 1060 } else 1061 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n"); 1062 break; 1063 default: 1064 return (EOPNOTSUPP); 1065 } 1066 return (error); 1067 } 1068 1069 static moduledata_t linux64_elf_mod = { 1070 "linux64elf", 1071 linux64_elf_modevent, 1072 0 1073 }; 1074 1075 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1076 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 1077 FEATURE(linux64, "Linux 64bit support"); 1078