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 <[email protected]> 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 #include <x86/linux/linux_x86_sigframe.h> 90 91 MODULE_VERSION(linux64, 1); 92 93 #define LINUX_VDSOPAGE_SIZE PAGE_SIZE * 2 94 #define LINUX_VDSOPAGE_LA48 (VM_MAXUSER_ADDRESS_LA48 - \ 95 LINUX_VDSOPAGE_SIZE) 96 #define LINUX_SHAREDPAGE_LA48 (LINUX_VDSOPAGE_LA48 - PAGE_SIZE) 97 /* 98 * PAGE_SIZE - the size 99 * of the native SHAREDPAGE 100 */ 101 #define LINUX_USRSTACK_LA48 LINUX_SHAREDPAGE_LA48 102 #define LINUX_PS_STRINGS_LA48 (LINUX_USRSTACK_LA48 - \ 103 sizeof(struct ps_strings)) 104 105 static int linux_szsigcode; 106 static vm_object_t linux_vdso_obj; 107 static char *linux_vdso_mapping; 108 extern char _binary_linux_vdso_so_o_start; 109 extern char _binary_linux_vdso_so_o_end; 110 static vm_offset_t linux_vdso_base; 111 112 extern struct sysent linux_sysent[LINUX_SYS_MAXSYSCALL]; 113 114 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler); 115 116 static int linux_copyout_strings(struct image_params *imgp, 117 uintptr_t *stack_base); 118 static int linux_fixup_elf(uintptr_t *stack_base, 119 struct image_params *iparams); 120 static bool linux_trans_osrel(const Elf_Note *note, int32_t *osrel); 121 static void linux_vdso_install(const void *param); 122 static void linux_vdso_deinstall(const void *param); 123 static void linux_vdso_reloc(char *mapping, Elf_Addr offset); 124 static void linux_set_syscall_retval(struct thread *td, int error); 125 static int linux_fetch_syscall_args(struct thread *td); 126 static void linux_exec_setregs(struct thread *td, struct image_params *imgp, 127 uintptr_t stack); 128 static void linux_exec_sysvec_init(void *param); 129 static int linux_on_exec_vmspace(struct proc *p, 130 struct image_params *imgp); 131 static void linux_set_fork_retval(struct thread *td); 132 static int linux_vsyscall(struct thread *td); 133 134 #define LINUX_T_UNKNOWN 255 135 static int _bsd_to_linux_trapcode[] = { 136 LINUX_T_UNKNOWN, /* 0 */ 137 6, /* 1 T_PRIVINFLT */ 138 LINUX_T_UNKNOWN, /* 2 */ 139 3, /* 3 T_BPTFLT */ 140 LINUX_T_UNKNOWN, /* 4 */ 141 LINUX_T_UNKNOWN, /* 5 */ 142 16, /* 6 T_ARITHTRAP */ 143 254, /* 7 T_ASTFLT */ 144 LINUX_T_UNKNOWN, /* 8 */ 145 13, /* 9 T_PROTFLT */ 146 1, /* 10 T_TRCTRAP */ 147 LINUX_T_UNKNOWN, /* 11 */ 148 14, /* 12 T_PAGEFLT */ 149 LINUX_T_UNKNOWN, /* 13 */ 150 17, /* 14 T_ALIGNFLT */ 151 LINUX_T_UNKNOWN, /* 15 */ 152 LINUX_T_UNKNOWN, /* 16 */ 153 LINUX_T_UNKNOWN, /* 17 */ 154 0, /* 18 T_DIVIDE */ 155 2, /* 19 T_NMI */ 156 4, /* 20 T_OFLOW */ 157 5, /* 21 T_BOUND */ 158 7, /* 22 T_DNA */ 159 8, /* 23 T_DOUBLEFLT */ 160 9, /* 24 T_FPOPFLT */ 161 10, /* 25 T_TSSFLT */ 162 11, /* 26 T_SEGNPFLT */ 163 12, /* 27 T_STKFLT */ 164 18, /* 28 T_MCHK */ 165 19, /* 29 T_XMMFLT */ 166 15 /* 30 T_RESERVED */ 167 }; 168 #define bsd_to_linux_trapcode(code) \ 169 ((code)<nitems(_bsd_to_linux_trapcode)? \ 170 _bsd_to_linux_trapcode[(code)]: \ 171 LINUX_T_UNKNOWN) 172 173 LINUX_VDSO_SYM_INTPTR(linux_rt_sigcode); 174 LINUX_VDSO_SYM_CHAR(linux_platform); 175 LINUX_VDSO_SYM_INTPTR(kern_timekeep_base); 176 LINUX_VDSO_SYM_INTPTR(kern_tsc_selector); 177 LINUX_VDSO_SYM_INTPTR(kern_cpu_selector); 178 179 static int 180 linux_fetch_syscall_args(struct thread *td) 181 { 182 struct proc *p; 183 struct trapframe *frame; 184 struct syscall_args *sa; 185 186 p = td->td_proc; 187 frame = td->td_frame; 188 sa = &td->td_sa; 189 190 sa->args[0] = frame->tf_rdi; 191 sa->args[1] = frame->tf_rsi; 192 sa->args[2] = frame->tf_rdx; 193 sa->args[3] = frame->tf_rcx; 194 sa->args[4] = frame->tf_r8; 195 sa->args[5] = frame->tf_r9; 196 sa->code = frame->tf_rax; 197 sa->original_code = sa->code; 198 199 if (sa->code >= p->p_sysent->sv_size) 200 /* nosys */ 201 sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1]; 202 else 203 sa->callp = &p->p_sysent->sv_table[sa->code]; 204 205 td->td_retval[0] = 0; 206 return (0); 207 } 208 209 static void 210 linux_set_syscall_retval(struct thread *td, int error) 211 { 212 struct trapframe *frame; 213 214 frame = td->td_frame; 215 216 switch (error) { 217 case 0: 218 frame->tf_rax = td->td_retval[0]; 219 frame->tf_r10 = frame->tf_rcx; 220 break; 221 222 case ERESTART: 223 /* 224 * Reconstruct pc, we know that 'syscall' is 2 bytes, 225 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 226 * We saved this in tf_err. 227 * 228 */ 229 frame->tf_rip -= frame->tf_err; 230 frame->tf_r10 = frame->tf_rcx; 231 break; 232 233 case EJUSTRETURN: 234 break; 235 236 default: 237 frame->tf_rax = bsd_to_linux_errno(error); 238 frame->tf_r10 = frame->tf_rcx; 239 break; 240 } 241 242 /* 243 * Differently from FreeBSD native ABI, on Linux only %rcx 244 * and %r11 values are not preserved across the syscall. 245 * Require full context restore to get all registers except 246 * those two restored at return to usermode. 247 * 248 * XXX: Would be great to be able to avoid PCB_FULL_IRET 249 * for the error == 0 case. 250 */ 251 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 252 } 253 254 static void 255 linux_set_fork_retval(struct thread *td) 256 { 257 struct trapframe *frame = td->td_frame; 258 259 frame->tf_rax = 0; 260 } 261 262 static int 263 linux_copyout_auxargs(struct image_params *imgp, uintptr_t base) 264 { 265 Elf_Auxargs *args; 266 Elf_Auxinfo *argarray, *pos; 267 struct proc *p; 268 int error, issetugid; 269 270 p = imgp->proc; 271 args = (Elf64_Auxargs *)imgp->auxargs; 272 argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP, 273 M_WAITOK | M_ZERO); 274 275 issetugid = p->p_flag & P_SUGID ? 1 : 0; 276 AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR, linux_vdso_base); 277 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature); 278 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 279 AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz); 280 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 281 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 282 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 283 AUXARGS_ENTRY(pos, AT_BASE, args->base); 284 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 285 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 286 AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid); 287 AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid); 288 AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid); 289 AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid); 290 AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid); 291 AUXARGS_ENTRY_PTR(pos, LINUX_AT_RANDOM, imgp->canary); 292 AUXARGS_ENTRY(pos, LINUX_AT_HWCAP2, 0); 293 if (imgp->execpathp != 0) 294 AUXARGS_ENTRY_PTR(pos, LINUX_AT_EXECFN, imgp->execpathp); 295 if (args->execfd != -1) 296 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 297 AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform)); 298 AUXARGS_ENTRY(pos, AT_NULL, 0); 299 300 free(imgp->auxargs, M_TEMP); 301 imgp->auxargs = NULL; 302 KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs")); 303 304 error = copyout(argarray, (void *)base, 305 sizeof(*argarray) * LINUX_AT_COUNT); 306 free(argarray, M_TEMP); 307 return (error); 308 } 309 310 static int 311 linux_fixup_elf(uintptr_t *stack_base, struct image_params *imgp) 312 { 313 Elf_Addr *base; 314 315 base = (Elf64_Addr *)*stack_base; 316 base--; 317 if (suword(base, (uint64_t)imgp->args->argc) == -1) 318 return (EFAULT); 319 320 *stack_base = (uintptr_t)base; 321 return (0); 322 } 323 324 /* 325 * Copy strings out to the new process address space, constructing new arg 326 * and env vector tables. Return a pointer to the base so that it can be used 327 * as the initial stack pointer. 328 */ 329 static int 330 linux_copyout_strings(struct image_params *imgp, uintptr_t *stack_base) 331 { 332 int argc, envc, error; 333 char **vectp; 334 char *stringp; 335 uintptr_t destp, ustringp; 336 struct ps_strings *arginfo; 337 char canary[LINUX_AT_RANDOM_LEN]; 338 size_t execpath_len; 339 struct proc *p; 340 341 p = imgp->proc; 342 arginfo = (struct ps_strings *)PROC_PS_STRINGS(p); 343 destp = (uintptr_t)arginfo; 344 345 if (imgp->execpath != NULL && imgp->auxargs != NULL) { 346 execpath_len = strlen(imgp->execpath) + 1; 347 destp -= execpath_len; 348 destp = rounddown2(destp, sizeof(void *)); 349 imgp->execpathp = (void *)destp; 350 error = copyout(imgp->execpath, imgp->execpathp, execpath_len); 351 if (error != 0) 352 return (error); 353 } 354 355 /* Prepare the canary for SSP. */ 356 arc4rand(canary, sizeof(canary), 0); 357 destp -= roundup(sizeof(canary), sizeof(void *)); 358 imgp->canary = (void *)destp; 359 error = copyout(canary, imgp->canary, sizeof(canary)); 360 if (error != 0) 361 return (error); 362 363 /* Allocate room for the argument and environment strings. */ 364 destp -= ARG_MAX - imgp->args->stringspace; 365 destp = rounddown2(destp, sizeof(void *)); 366 ustringp = destp; 367 368 if (imgp->auxargs) { 369 /* 370 * Allocate room on the stack for the ELF auxargs 371 * array. It has LINUX_AT_COUNT entries. 372 */ 373 destp -= LINUX_AT_COUNT * sizeof(Elf64_Auxinfo); 374 destp = rounddown2(destp, sizeof(void *)); 375 } 376 377 vectp = (char **)destp; 378 379 /* 380 * Allocate room for the argv[] and env vectors including the 381 * terminating NULL pointers. 382 */ 383 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1; 384 385 /* 386 * Starting with 2.24, glibc depends on a 16-byte stack alignment. 387 * One "long argc" will be prepended later. 388 */ 389 vectp = (char **)((((uintptr_t)vectp + 8) & ~0xF) - 8); 390 391 /* vectp also becomes our initial stack base. */ 392 *stack_base = (uintptr_t)vectp; 393 394 stringp = imgp->args->begin_argv; 395 argc = imgp->args->argc; 396 envc = imgp->args->envc; 397 398 /* Copy out strings - arguments and environment. */ 399 error = copyout(stringp, (void *)ustringp, 400 ARG_MAX - imgp->args->stringspace); 401 if (error != 0) 402 return (error); 403 404 /* Fill in "ps_strings" struct for ps, w, etc. */ 405 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 || 406 suword(&arginfo->ps_nargvstr, argc) != 0) 407 return (EFAULT); 408 409 /* Fill in argument portion of vector table. */ 410 for (; argc > 0; --argc) { 411 if (suword(vectp++, ustringp) != 0) 412 return (EFAULT); 413 while (*stringp++ != 0) 414 ustringp++; 415 ustringp++; 416 } 417 418 /* A null vector table pointer separates the argp's from the envp's. */ 419 if (suword(vectp++, 0) != 0) 420 return (EFAULT); 421 422 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 || 423 suword(&arginfo->ps_nenvstr, envc) != 0) 424 return (EFAULT); 425 426 /* Fill in environment portion of vector table. */ 427 for (; envc > 0; --envc) { 428 if (suword(vectp++, ustringp) != 0) 429 return (EFAULT); 430 while (*stringp++ != 0) 431 ustringp++; 432 ustringp++; 433 } 434 435 /* The end of the vector table is a null pointer. */ 436 if (suword(vectp, 0) != 0) 437 return (EFAULT); 438 439 if (imgp->auxargs) { 440 vectp++; 441 error = imgp->sysent->sv_copyout_auxargs(imgp, 442 (uintptr_t)vectp); 443 if (error != 0) 444 return (error); 445 } 446 447 return (0); 448 } 449 450 /* 451 * Reset registers to default values on exec. 452 */ 453 static void 454 linux_exec_setregs(struct thread *td, struct image_params *imgp, 455 uintptr_t stack) 456 { 457 struct trapframe *regs; 458 struct pcb *pcb; 459 register_t saved_rflags; 460 461 regs = td->td_frame; 462 pcb = td->td_pcb; 463 464 if (td->td_proc->p_md.md_ldt != NULL) 465 user_ldt_free(td); 466 467 pcb->pcb_fsbase = 0; 468 pcb->pcb_gsbase = 0; 469 clear_pcb_flags(pcb, PCB_32BIT); 470 pcb->pcb_initial_fpucw = __LINUX_NPXCW__; 471 set_pcb_flags(pcb, PCB_FULL_IRET); 472 473 saved_rflags = regs->tf_rflags & PSL_T; 474 bzero((char *)regs, sizeof(struct trapframe)); 475 regs->tf_rip = imgp->entry_addr; 476 regs->tf_rsp = stack; 477 regs->tf_rflags = PSL_USER | saved_rflags; 478 regs->tf_ss = _udatasel; 479 regs->tf_cs = _ucodesel; 480 regs->tf_ds = _udatasel; 481 regs->tf_es = _udatasel; 482 regs->tf_fs = _ufssel; 483 regs->tf_gs = _ugssel; 484 regs->tf_flags = TF_HASSEGS; 485 486 x86_clear_dbregs(pcb); 487 488 /* 489 * Drop the FP state if we hold it, so that the process gets a 490 * clean FP state if it uses the FPU again. 491 */ 492 fpstate_drop(td); 493 } 494 495 /* 496 * Copied from amd64/amd64/machdep.c 497 * 498 * XXX fpu state need? don't think so 499 */ 500 int 501 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args) 502 { 503 struct proc *p; 504 struct l_ucontext uc; 505 struct l_sigcontext *context; 506 struct trapframe *regs; 507 unsigned long rflags; 508 int error; 509 ksiginfo_t ksi; 510 511 regs = td->td_frame; 512 error = copyin((void *)regs->tf_rbx, &uc, sizeof(uc)); 513 if (error != 0) 514 return (error); 515 516 p = td->td_proc; 517 context = &uc.uc_mcontext; 518 rflags = context->sc_rflags; 519 520 /* 521 * Don't allow users to change privileged or reserved flags. 522 */ 523 /* 524 * XXX do allow users to change the privileged flag PSL_RF. 525 * The cpu sets PSL_RF in tf_rflags for faults. Debuggers 526 * should sometimes set it there too. tf_rflags is kept in 527 * the signal context during signal handling and there is no 528 * other place to remember it, so the PSL_RF bit may be 529 * corrupted by the signal handler without us knowing. 530 * Corruption of the PSL_RF bit at worst causes one more or 531 * one less debugger trap, so allowing it is fairly harmless. 532 */ 533 if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) { 534 uprintf("pid %d comm %s linux mangled rflags %#lx\n", 535 p->p_pid, p->p_comm, rflags); 536 return (EINVAL); 537 } 538 539 /* 540 * Don't allow users to load a valid privileged %cs. Let the 541 * hardware check for invalid selectors, excess privilege in 542 * other selectors, invalid %eip's and invalid %esp's. 543 */ 544 if (!CS_SECURE(context->sc_cs)) { 545 uprintf("pid %d comm %s linux mangled cs %#x\n", 546 p->p_pid, p->p_comm, context->sc_cs); 547 ksiginfo_init_trap(&ksi); 548 ksi.ksi_signo = SIGBUS; 549 ksi.ksi_code = BUS_OBJERR; 550 ksi.ksi_trapno = T_PROTFLT; 551 ksi.ksi_addr = (void *)regs->tf_rip; 552 trapsignal(td, &ksi); 553 return (EINVAL); 554 } 555 556 PROC_LOCK(p); 557 linux_to_bsd_sigset(&uc.uc_sigmask, &td->td_sigmask); 558 SIG_CANTMASK(td->td_sigmask); 559 signotify(td); 560 PROC_UNLOCK(p); 561 562 regs->tf_rdi = context->sc_rdi; 563 regs->tf_rsi = context->sc_rsi; 564 regs->tf_rdx = context->sc_rdx; 565 regs->tf_rbp = context->sc_rbp; 566 regs->tf_rbx = context->sc_rbx; 567 regs->tf_rcx = context->sc_rcx; 568 regs->tf_rax = context->sc_rax; 569 regs->tf_rip = context->sc_rip; 570 regs->tf_rsp = context->sc_rsp; 571 regs->tf_r8 = context->sc_r8; 572 regs->tf_r9 = context->sc_r9; 573 regs->tf_r10 = context->sc_r10; 574 regs->tf_r11 = context->sc_r11; 575 regs->tf_r12 = context->sc_r12; 576 regs->tf_r13 = context->sc_r13; 577 regs->tf_r14 = context->sc_r14; 578 regs->tf_r15 = context->sc_r15; 579 regs->tf_cs = context->sc_cs; 580 regs->tf_err = context->sc_err; 581 regs->tf_rflags = rflags; 582 583 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 584 return (EJUSTRETURN); 585 } 586 587 /* 588 * copied from amd64/amd64/machdep.c 589 * 590 * Send an interrupt to process. 591 */ 592 static void 593 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 594 { 595 struct l_rt_sigframe sf, *sfp; 596 struct proc *p; 597 struct thread *td; 598 struct sigacts *psp; 599 caddr_t sp; 600 struct trapframe *regs; 601 int sig, code; 602 int oonstack; 603 604 td = curthread; 605 p = td->td_proc; 606 PROC_LOCK_ASSERT(p, MA_OWNED); 607 sig = linux_translate_traps(ksi->ksi_signo, ksi->ksi_trapno); 608 psp = p->p_sigacts; 609 code = ksi->ksi_code; 610 mtx_assert(&psp->ps_mtx, MA_OWNED); 611 regs = td->td_frame; 612 oonstack = sigonstack(regs->tf_rsp); 613 614 LINUX_CTR4(rt_sendsig, "%p, %d, %p, %u", 615 catcher, sig, mask, code); 616 617 /* Save user context. */ 618 bzero(&sf, sizeof(sf)); 619 bsd_to_linux_sigset(mask, &sf.sf_uc.uc_sigmask); 620 bsd_to_linux_sigset(mask, &sf.sf_uc.uc_mcontext.sc_mask); 621 622 sf.sf_uc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp); 623 sf.sf_uc.uc_stack.ss_size = td->td_sigstk.ss_size; 624 sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) 625 ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE; 626 627 sf.sf_uc.uc_mcontext.sc_rdi = regs->tf_rdi; 628 sf.sf_uc.uc_mcontext.sc_rsi = regs->tf_rsi; 629 sf.sf_uc.uc_mcontext.sc_rdx = regs->tf_rdx; 630 sf.sf_uc.uc_mcontext.sc_rbp = regs->tf_rbp; 631 sf.sf_uc.uc_mcontext.sc_rbx = regs->tf_rbx; 632 sf.sf_uc.uc_mcontext.sc_rcx = regs->tf_rcx; 633 sf.sf_uc.uc_mcontext.sc_rax = regs->tf_rax; 634 sf.sf_uc.uc_mcontext.sc_rip = regs->tf_rip; 635 sf.sf_uc.uc_mcontext.sc_rsp = regs->tf_rsp; 636 sf.sf_uc.uc_mcontext.sc_r8 = regs->tf_r8; 637 sf.sf_uc.uc_mcontext.sc_r9 = regs->tf_r9; 638 sf.sf_uc.uc_mcontext.sc_r10 = regs->tf_r10; 639 sf.sf_uc.uc_mcontext.sc_r11 = regs->tf_r11; 640 sf.sf_uc.uc_mcontext.sc_r12 = regs->tf_r12; 641 sf.sf_uc.uc_mcontext.sc_r13 = regs->tf_r13; 642 sf.sf_uc.uc_mcontext.sc_r14 = regs->tf_r14; 643 sf.sf_uc.uc_mcontext.sc_r15 = regs->tf_r15; 644 sf.sf_uc.uc_mcontext.sc_cs = regs->tf_cs; 645 sf.sf_uc.uc_mcontext.sc_rflags = regs->tf_rflags; 646 sf.sf_uc.uc_mcontext.sc_err = regs->tf_err; 647 sf.sf_uc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code); 648 sf.sf_uc.uc_mcontext.sc_cr2 = (register_t)ksi->ksi_addr; 649 650 /* Allocate space for the signal handler context. */ 651 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack && 652 SIGISMEMBER(psp->ps_sigonstack, sig)) { 653 sp = (caddr_t)td->td_sigstk.ss_sp + td->td_sigstk.ss_size; 654 } else 655 sp = (caddr_t)regs->tf_rsp - 128; 656 sp -= sizeof(struct l_rt_sigframe); 657 /* Align to 16 bytes. */ 658 sfp = (struct l_rt_sigframe *)((unsigned long)sp & ~0xFul); 659 660 /* Translate the signal. */ 661 sig = bsd_to_linux_signal(sig); 662 663 /* Build the argument list for the signal handler. */ 664 regs->tf_rdi = sig; /* arg 1 in %rdi */ 665 regs->tf_rax = 0; 666 regs->tf_rsi = (register_t)&sfp->sf_si; /* arg 2 in %rsi */ 667 regs->tf_rdx = (register_t)&sfp->sf_uc; /* arg 3 in %rdx */ 668 regs->tf_rcx = (register_t)catcher; 669 670 /* Fill in POSIX parts. */ 671 siginfo_to_lsiginfo(&ksi->ksi_info, &sf.sf_si, sig); 672 673 mtx_unlock(&psp->ps_mtx); 674 PROC_UNLOCK(p); 675 676 /* Copy the sigframe out to the user's stack. */ 677 if (copyout(&sf, sfp, sizeof(*sfp)) != 0) { 678 uprintf("pid %d comm %s has trashed its stack, killing\n", 679 p->p_pid, p->p_comm); 680 PROC_LOCK(p); 681 sigexit(td, SIGILL); 682 } 683 684 regs->tf_rsp = (long)sfp; 685 regs->tf_rip = linux_rt_sigcode; 686 regs->tf_rflags &= ~(PSL_T | PSL_D); 687 regs->tf_cs = _ucodesel; 688 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 689 PROC_LOCK(p); 690 mtx_lock(&psp->ps_mtx); 691 } 692 693 #define LINUX_VSYSCALL_START (-10UL << 20) 694 #define LINUX_VSYSCALL_SZ 1024 695 696 const unsigned long linux_vsyscall_vector[] = { 697 LINUX_SYS_gettimeofday, 698 LINUX_SYS_linux_time, 699 LINUX_SYS_linux_getcpu, 700 }; 701 702 static int 703 linux_vsyscall(struct thread *td) 704 { 705 struct trapframe *frame; 706 uint64_t retqaddr; 707 int code, traced; 708 int error; 709 710 frame = td->td_frame; 711 712 /* Check %rip for vsyscall area. */ 713 if (__predict_true(frame->tf_rip < LINUX_VSYSCALL_START)) 714 return (EINVAL); 715 if ((frame->tf_rip & (LINUX_VSYSCALL_SZ - 1)) != 0) 716 return (EINVAL); 717 code = (frame->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SZ; 718 if (code >= nitems(linux_vsyscall_vector)) 719 return (EINVAL); 720 721 /* 722 * vsyscall called as callq *(%rax), so we must 723 * use return address from %rsp and also fixup %rsp. 724 */ 725 error = copyin((void *)frame->tf_rsp, &retqaddr, sizeof(retqaddr)); 726 if (error) 727 return (error); 728 729 frame->tf_rip = retqaddr; 730 frame->tf_rax = linux_vsyscall_vector[code]; 731 frame->tf_rsp += 8; 732 733 traced = (frame->tf_flags & PSL_T); 734 735 amd64_syscall(td, traced); 736 737 return (0); 738 } 739 740 struct sysentvec elf_linux_sysvec = { 741 .sv_size = LINUX_SYS_MAXSYSCALL, 742 .sv_table = linux_sysent, 743 .sv_fixup = linux_fixup_elf, 744 .sv_sendsig = linux_rt_sendsig, 745 .sv_sigcode = &_binary_linux_vdso_so_o_start, 746 .sv_szsigcode = &linux_szsigcode, 747 .sv_name = "Linux ELF64", 748 .sv_coredump = elf64_coredump, 749 .sv_elf_core_osabi = ELFOSABI_NONE, 750 .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR, 751 .sv_elf_core_prepare_notes = linux64_prepare_notes, 752 .sv_imgact_try = linux_exec_imgact_try, 753 .sv_minsigstksz = LINUX_MINSIGSTKSZ, 754 .sv_minuser = VM_MIN_ADDRESS, 755 .sv_maxuser = VM_MAXUSER_ADDRESS_LA48, 756 .sv_usrstack = LINUX_USRSTACK_LA48, 757 .sv_psstrings = LINUX_PS_STRINGS_LA48, 758 .sv_psstringssz = sizeof(struct ps_strings), 759 .sv_stackprot = VM_PROT_ALL, 760 .sv_copyout_auxargs = linux_copyout_auxargs, 761 .sv_copyout_strings = linux_copyout_strings, 762 .sv_setregs = linux_exec_setregs, 763 .sv_fixlimit = NULL, 764 .sv_maxssiz = NULL, 765 .sv_flags = SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_DISCIGN | 766 SV_SIG_WAITNDQ | SV_TIMEKEEP, 767 .sv_set_syscall_retval = linux_set_syscall_retval, 768 .sv_fetch_syscall_args = linux_fetch_syscall_args, 769 .sv_syscallnames = NULL, 770 .sv_shared_page_base = LINUX_SHAREDPAGE_LA48, 771 .sv_shared_page_len = PAGE_SIZE, 772 .sv_schedtail = linux_schedtail, 773 .sv_thread_detach = linux_thread_detach, 774 .sv_trap = linux_vsyscall, 775 .sv_onexec = linux_on_exec_vmspace, 776 .sv_onexit = linux_on_exit, 777 .sv_ontdexit = linux_thread_dtor, 778 .sv_setid_allowed = &linux_setid_allowed_query, 779 .sv_set_fork_retval = linux_set_fork_retval, 780 }; 781 782 static int 783 linux_on_exec_vmspace(struct proc *p, struct image_params *imgp) 784 { 785 int error; 786 787 error = linux_map_vdso(p, linux_vdso_obj, linux_vdso_base, 788 LINUX_VDSOPAGE_SIZE, imgp); 789 if (error == 0) 790 linux_on_exec(p, imgp); 791 return (error); 792 } 793 794 /* 795 * linux_vdso_install() and linux_exec_sysvec_init() must be called 796 * after exec_sysvec_init() which is SI_SUB_EXEC (SI_ORDER_ANY). 797 */ 798 static void 799 linux_exec_sysvec_init(void *param) 800 { 801 l_uintptr_t *ktimekeep_base, *ktsc_selector; 802 struct sysentvec *sv; 803 ptrdiff_t tkoff; 804 805 sv = param; 806 amd64_lower_shared_page(sv); 807 /* Fill timekeep_base */ 808 exec_sysvec_init(sv); 809 810 tkoff = kern_timekeep_base - linux_vdso_base; 811 ktimekeep_base = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 812 *ktimekeep_base = sv->sv_timekeep_base; 813 814 tkoff = kern_tsc_selector - linux_vdso_base; 815 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 816 *ktsc_selector = linux_vdso_tsc_selector_idx(); 817 if (bootverbose) 818 printf("Linux x86-64 vDSO tsc_selector: %lu\n", *ktsc_selector); 819 820 tkoff = kern_cpu_selector - linux_vdso_base; 821 ktsc_selector = (l_uintptr_t *)(linux_vdso_mapping + tkoff); 822 *ktsc_selector = linux_vdso_cpu_selector_idx(); 823 if (bootverbose) 824 printf("Linux x86-64 vDSO cpu_selector: %lu\n", *ktsc_selector); 825 } 826 SYSINIT(elf_linux_exec_sysvec_init, SI_SUB_EXEC + 1, SI_ORDER_ANY, 827 linux_exec_sysvec_init, &elf_linux_sysvec); 828 829 static void 830 linux_vdso_install(const void *param) 831 { 832 char *vdso_start = &_binary_linux_vdso_so_o_start; 833 char *vdso_end = &_binary_linux_vdso_so_o_end; 834 835 linux_szsigcode = vdso_end - vdso_start; 836 MPASS(linux_szsigcode <= LINUX_VDSOPAGE_SIZE); 837 838 linux_vdso_base = LINUX_VDSOPAGE_LA48; 839 if (hw_lower_amd64_sharedpage != 0) 840 linux_vdso_base -= PAGE_SIZE; 841 842 __elfN(linux_vdso_fixup)(vdso_start, linux_vdso_base); 843 844 linux_vdso_obj = __elfN(linux_shared_page_init) 845 (&linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 846 bcopy(vdso_start, linux_vdso_mapping, linux_szsigcode); 847 848 linux_vdso_reloc(linux_vdso_mapping, linux_vdso_base); 849 } 850 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC + 1, SI_ORDER_FIRST, 851 linux_vdso_install, NULL); 852 853 static void 854 linux_vdso_deinstall(const void *param) 855 { 856 857 __elfN(linux_shared_page_fini)(linux_vdso_obj, 858 linux_vdso_mapping, LINUX_VDSOPAGE_SIZE); 859 } 860 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST, 861 linux_vdso_deinstall, NULL); 862 863 static void 864 linux_vdso_reloc(char *mapping, Elf_Addr offset) 865 { 866 const Elf_Ehdr *ehdr; 867 const Elf_Shdr *shdr; 868 Elf64_Addr *where, val; 869 Elf_Size rtype, symidx; 870 const Elf_Rela *rela; 871 Elf_Addr addr, addend; 872 int relacnt; 873 int i, j; 874 875 MPASS(offset != 0); 876 877 relacnt = 0; 878 ehdr = (const Elf_Ehdr *)mapping; 879 shdr = (const Elf_Shdr *)(mapping + ehdr->e_shoff); 880 for (i = 0; i < ehdr->e_shnum; i++) 881 { 882 switch (shdr[i].sh_type) { 883 case SHT_REL: 884 printf("Linux x86_64 vDSO: unexpected Rel section\n"); 885 break; 886 case SHT_RELA: 887 rela = (const Elf_Rela *)(mapping + shdr[i].sh_offset); 888 relacnt = shdr[i].sh_size / sizeof(*rela); 889 } 890 } 891 892 for (j = 0; j < relacnt; j++, rela++) { 893 where = (Elf_Addr *)(mapping + rela->r_offset); 894 addend = rela->r_addend; 895 rtype = ELF_R_TYPE(rela->r_info); 896 symidx = ELF_R_SYM(rela->r_info); 897 898 switch (rtype) { 899 case R_X86_64_NONE: /* none */ 900 break; 901 902 case R_X86_64_RELATIVE: /* B + A */ 903 addr = (Elf_Addr)(offset + addend); 904 val = addr; 905 if (*where != val) 906 *where = val; 907 break; 908 case R_X86_64_IRELATIVE: 909 printf("Linux x86_64 vDSO: unexpected ifunc relocation, " 910 "symbol index %ld\n", symidx); 911 break; 912 default: 913 printf("Linux x86_64 vDSO: unexpected relocation type %ld, " 914 "symbol index %ld\n", rtype, symidx); 915 } 916 } 917 } 918 919 static char GNULINUX_ABI_VENDOR[] = "GNU"; 920 static int GNULINUX_ABI_DESC = 0; 921 922 static bool 923 linux_trans_osrel(const Elf_Note *note, int32_t *osrel) 924 { 925 const Elf32_Word *desc; 926 uintptr_t p; 927 928 p = (uintptr_t)(note + 1); 929 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 930 931 desc = (const Elf32_Word *)p; 932 if (desc[0] != GNULINUX_ABI_DESC) 933 return (false); 934 935 /* 936 * For Linux we encode osrel using the Linux convention of 937 * (version << 16) | (major << 8) | (minor) 938 * See macro in linux_mib.h 939 */ 940 *osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]); 941 942 return (true); 943 } 944 945 static Elf_Brandnote linux64_brandnote = { 946 .hdr.n_namesz = sizeof(GNULINUX_ABI_VENDOR), 947 .hdr.n_descsz = 16, 948 .hdr.n_type = 1, 949 .vendor = GNULINUX_ABI_VENDOR, 950 .flags = BN_TRANSLATE_OSREL, 951 .trans_osrel = linux_trans_osrel 952 }; 953 954 static Elf64_Brandinfo linux_glibc2brand = { 955 .brand = ELFOSABI_LINUX, 956 .machine = EM_X86_64, 957 .compat_3_brand = "Linux", 958 .emul_path = linux_emul_path, 959 .interp_path = "/lib64/ld-linux-x86-64.so.2", 960 .sysvec = &elf_linux_sysvec, 961 .interp_newpath = NULL, 962 .brand_note = &linux64_brandnote, 963 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 964 }; 965 966 static Elf64_Brandinfo linux_glibc2brandshort = { 967 .brand = ELFOSABI_LINUX, 968 .machine = EM_X86_64, 969 .compat_3_brand = "Linux", 970 .emul_path = linux_emul_path, 971 .interp_path = "/lib64/ld-linux.so.2", 972 .sysvec = &elf_linux_sysvec, 973 .interp_newpath = NULL, 974 .brand_note = &linux64_brandnote, 975 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 976 }; 977 978 static Elf64_Brandinfo linux_muslbrand = { 979 .brand = ELFOSABI_LINUX, 980 .machine = EM_X86_64, 981 .compat_3_brand = "Linux", 982 .emul_path = linux_emul_path, 983 .interp_path = "/lib/ld-musl-x86_64.so.1", 984 .sysvec = &elf_linux_sysvec, 985 .interp_newpath = NULL, 986 .brand_note = &linux64_brandnote, 987 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE | 988 LINUX_BI_FUTEX_REQUEUE 989 }; 990 991 Elf64_Brandinfo *linux_brandlist[] = { 992 &linux_glibc2brand, 993 &linux_glibc2brandshort, 994 &linux_muslbrand, 995 NULL 996 }; 997 998 static int 999 linux64_elf_modevent(module_t mod, int type, void *data) 1000 { 1001 Elf64_Brandinfo **brandinfo; 1002 int error; 1003 struct linux_ioctl_handler **lihp; 1004 1005 error = 0; 1006 1007 switch(type) { 1008 case MOD_LOAD: 1009 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1010 ++brandinfo) 1011 if (elf64_insert_brand_entry(*brandinfo) < 0) 1012 error = EINVAL; 1013 if (error == 0) { 1014 SET_FOREACH(lihp, linux_ioctl_handler_set) 1015 linux_ioctl_register_handler(*lihp); 1016 stclohz = (stathz ? stathz : hz); 1017 if (bootverbose) 1018 printf("Linux x86-64 ELF exec handler installed\n"); 1019 } else 1020 printf("cannot insert Linux x86-64 ELF brand handler\n"); 1021 break; 1022 case MOD_UNLOAD: 1023 for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL; 1024 ++brandinfo) 1025 if (elf64_brand_inuse(*brandinfo)) 1026 error = EBUSY; 1027 if (error == 0) { 1028 for (brandinfo = &linux_brandlist[0]; 1029 *brandinfo != NULL; ++brandinfo) 1030 if (elf64_remove_brand_entry(*brandinfo) < 0) 1031 error = EINVAL; 1032 } 1033 if (error == 0) { 1034 SET_FOREACH(lihp, linux_ioctl_handler_set) 1035 linux_ioctl_unregister_handler(*lihp); 1036 if (bootverbose) 1037 printf("Linux x86_64 ELF exec handler removed\n"); 1038 } else 1039 printf("Could not deinstall Linux x86_64 ELF interpreter entry\n"); 1040 break; 1041 default: 1042 return (EOPNOTSUPP); 1043 } 1044 return (error); 1045 } 1046 1047 static moduledata_t linux64_elf_mod = { 1048 "linux64elf", 1049 linux64_elf_modevent, 1050 0 1051 }; 1052 1053 DECLARE_MODULE_TIED(linux64elf, linux64_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY); 1054 MODULE_DEPEND(linux64elf, linux_common, 1, 1, 1); 1055 FEATURE(linux64, "Linux 64bit support"); 1056