1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1982, 1986 The Regents of the University of California. 5 * Copyright (c) 1989, 1990 William Jolitz 6 * Copyright (c) 1994 John Dyson 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * the Systems Programming Group of the University of Utah Computer 11 * Science Department, and William Jolitz. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 42 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include "opt_isa.h" 49 #include "opt_cpu.h" 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/bio.h> 54 #include <sys/buf.h> 55 #include <sys/kernel.h> 56 #include <sys/ktr.h> 57 #include <sys/lock.h> 58 #include <sys/malloc.h> 59 #include <sys/mbuf.h> 60 #include <sys/mutex.h> 61 #include <sys/priv.h> 62 #include <sys/proc.h> 63 #include <sys/procctl.h> 64 #include <sys/smp.h> 65 #include <sys/sysctl.h> 66 #include <sys/sysent.h> 67 #include <sys/unistd.h> 68 #include <sys/vnode.h> 69 #include <sys/vmmeter.h> 70 #include <sys/wait.h> 71 72 #include <machine/cpu.h> 73 #include <machine/md_var.h> 74 #include <machine/pcb.h> 75 #include <machine/smp.h> 76 #include <machine/specialreg.h> 77 #include <machine/tss.h> 78 79 #include <vm/vm.h> 80 #include <vm/vm_extern.h> 81 #include <vm/vm_kern.h> 82 #include <vm/vm_page.h> 83 #include <vm/vm_map.h> 84 #include <vm/vm_param.h> 85 86 _Static_assert(OFFSETOF_MONITORBUF == offsetof(struct pcpu, pc_monitorbuf), 87 "OFFSETOF_MONITORBUF does not correspond with offset of pc_monitorbuf."); 88 89 void 90 set_top_of_stack_td(struct thread *td) 91 { 92 td->td_md.md_stack_base = td->td_kstack + 93 td->td_kstack_pages * PAGE_SIZE; 94 } 95 96 struct savefpu * 97 get_pcb_user_save_td(struct thread *td) 98 { 99 KASSERT(((vm_offset_t)td->td_md.md_usr_fpu_save % 100 XSAVE_AREA_ALIGN) == 0, 101 ("Unaligned pcb_user_save area ptr %p td %p", 102 td->td_md.md_usr_fpu_save, td)); 103 return (td->td_md.md_usr_fpu_save); 104 } 105 106 struct pcb * 107 get_pcb_td(struct thread *td) 108 { 109 110 return (&td->td_md.md_pcb); 111 } 112 113 struct savefpu * 114 get_pcb_user_save_pcb(struct pcb *pcb) 115 { 116 struct thread *td; 117 118 td = __containerof(pcb, struct thread, td_md.md_pcb); 119 return (get_pcb_user_save_td(td)); 120 } 121 122 void * 123 alloc_fpusave(int flags) 124 { 125 void *res; 126 struct savefpu_ymm *sf; 127 128 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags); 129 if (use_xsave) { 130 sf = (struct savefpu_ymm *)res; 131 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd)); 132 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask; 133 } 134 return (res); 135 } 136 137 /* 138 * Common code shared between cpu_fork() and cpu_copy_thread() for 139 * initializing a thread. 140 */ 141 static void 142 copy_thread(struct thread *td1, struct thread *td2) 143 { 144 struct pcb *pcb2; 145 146 pcb2 = td2->td_pcb; 147 148 /* Ensure that td1's pcb is up to date for user threads. */ 149 if ((td2->td_pflags & TDP_KTHREAD) == 0) { 150 MPASS(td1 == curthread); 151 fpuexit(td1); 152 update_pcb_bases(td1->td_pcb); 153 } 154 155 /* Copy td1's pcb */ 156 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 157 158 /* Properly initialize pcb_save */ 159 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 160 161 /* Kernel threads start with clean FPU and segment bases. */ 162 if ((td2->td_pflags & TDP_KTHREAD) != 0) { 163 pcb2->pcb_fsbase = 0; 164 pcb2->pcb_gsbase = 0; 165 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE | 166 PCB_KERNFPU | PCB_KERNFPU_THR); 167 } else { 168 MPASS((pcb2->pcb_flags & (PCB_KERNFPU | PCB_KERNFPU_THR)) == 0); 169 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2), 170 cpu_max_ext_state_size); 171 } 172 173 td2->td_frame = (struct trapframe *)td2->td_md.md_stack_base - 1; 174 175 /* 176 * Set registers for trampoline to user mode. Leave space for the 177 * return address on stack. These are the kernel mode register values. 178 */ 179 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */ 180 pcb2->pcb_rbp = 0; 181 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *); 182 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */ 183 pcb2->pcb_rip = (register_t)fork_trampoline; 184 /*- 185 * pcb2->pcb_dr*: cloned above. 186 * pcb2->pcb_savefpu: cloned above. 187 * pcb2->pcb_flags: cloned above. 188 * pcb2->pcb_onfault: cloned above (always NULL here?). 189 * pcb2->pcb_[fg]sbase: cloned above 190 */ 191 192 pcb2->pcb_tssp = NULL; 193 194 /* Setup to release spin count in fork_exit(). */ 195 td2->td_md.md_spinlock_count = 1; 196 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 197 pmap_thread_init_invl_gen(td2); 198 199 /* 200 * Copy the trap frame for the return to user mode as if from a syscall. 201 * This copies most of the user mode register values. Some of these 202 * registers are rewritten by cpu_set_upcall() and linux_set_upcall(). 203 */ 204 if ((td1->td_proc->p_flag & P_KPROC) == 0) { 205 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 206 207 /* 208 * If the current thread has the trap bit set (i.e. a debugger 209 * had single stepped the process to the system call), we need 210 * to clear the trap flag from the new frame. Otherwise, the new 211 * thread will receive a (likely unexpected) SIGTRAP when it 212 * executes the first instruction after returning to userland. 213 */ 214 td2->td_frame->tf_rflags &= ~PSL_T; 215 } 216 } 217 218 /* 219 * Finish a fork operation, with process p2 nearly set up. 220 * Copy and update the pcb, set up the stack so that the child 221 * ready to run and return to user mode. 222 */ 223 void 224 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 225 { 226 struct proc *p1; 227 struct pcb *pcb2; 228 struct mdproc *mdp1, *mdp2; 229 struct proc_ldt *pldt; 230 231 p1 = td1->td_proc; 232 if ((flags & RFPROC) == 0) { 233 if ((flags & RFMEM) == 0) { 234 /* unshare user LDT */ 235 mdp1 = &p1->p_md; 236 mtx_lock(&dt_lock); 237 if ((pldt = mdp1->md_ldt) != NULL && 238 pldt->ldt_refcnt > 1 && 239 user_ldt_alloc(p1, 1) == NULL) 240 panic("could not copy LDT"); 241 mtx_unlock(&dt_lock); 242 } 243 return; 244 } 245 246 /* Point the stack and pcb to the actual location */ 247 set_top_of_stack_td(td2); 248 td2->td_pcb = pcb2 = get_pcb_td(td2); 249 250 copy_thread(td1, td2); 251 252 /* Reset debug registers in the new process */ 253 x86_clear_dbregs(pcb2); 254 255 /* Point mdproc and then copy over p1's contents */ 256 mdp2 = &p2->p_md; 257 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 258 259 /* Set child return values. */ 260 p2->p_sysent->sv_set_fork_retval(td2); 261 262 /* As on i386, do not copy io permission bitmap. */ 263 pcb2->pcb_tssp = NULL; 264 265 /* New segment registers. */ 266 set_pcb_flags_raw(pcb2, PCB_FULL_IRET); 267 268 /* Copy the LDT, if necessary. */ 269 mdp1 = &td1->td_proc->p_md; 270 mdp2 = &p2->p_md; 271 if (mdp1->md_ldt == NULL) { 272 mdp2->md_ldt = NULL; 273 return; 274 } 275 mtx_lock(&dt_lock); 276 if (mdp1->md_ldt != NULL) { 277 if (flags & RFMEM) { 278 mdp1->md_ldt->ldt_refcnt++; 279 mdp2->md_ldt = mdp1->md_ldt; 280 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct 281 system_segment_descriptor)); 282 } else { 283 mdp2->md_ldt = NULL; 284 mdp2->md_ldt = user_ldt_alloc(p2, 0); 285 if (mdp2->md_ldt == NULL) 286 panic("could not copy LDT"); 287 amd64_set_ldt_data(td2, 0, max_ldt_segment, 288 (struct user_segment_descriptor *) 289 mdp1->md_ldt->ldt_base); 290 } 291 } else 292 mdp2->md_ldt = NULL; 293 mtx_unlock(&dt_lock); 294 295 /* 296 * Now, cpu_switch() can schedule the new process. 297 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 298 * containing the return address when exiting cpu_switch. 299 * This will normally be to fork_trampoline(), which will have 300 * %rbx loaded with the new proc's pointer. fork_trampoline() 301 * will set up a stack to call fork_return(p, frame); to complete 302 * the return to user-mode. 303 */ 304 } 305 306 void 307 x86_set_fork_retval(struct thread *td) 308 { 309 struct trapframe *frame = td->td_frame; 310 311 frame->tf_rax = 0; /* Child returns zero */ 312 frame->tf_rflags &= ~PSL_C; /* success */ 313 frame->tf_rdx = 1; /* System V emulation */ 314 } 315 316 /* 317 * Intercept the return address from a freshly forked process that has NOT 318 * been scheduled yet. 319 * 320 * This is needed to make kernel threads stay in kernel mode. 321 */ 322 void 323 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 324 { 325 /* 326 * Note that the trap frame follows the args, so the function 327 * is really called like this: func(arg, frame); 328 */ 329 td->td_pcb->pcb_r12 = (long) func; /* function */ 330 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 331 } 332 333 void 334 cpu_exit(struct thread *td) 335 { 336 337 /* 338 * If this process has a custom LDT, release it. 339 */ 340 if (td->td_proc->p_md.md_ldt != NULL) 341 user_ldt_free(td); 342 } 343 344 void 345 cpu_thread_exit(struct thread *td) 346 { 347 struct pcb *pcb; 348 349 critical_enter(); 350 if (td == PCPU_GET(fpcurthread)) 351 fpudrop(); 352 critical_exit(); 353 354 pcb = td->td_pcb; 355 356 /* Disable any hardware breakpoints. */ 357 if (pcb->pcb_flags & PCB_DBREGS) { 358 reset_dbregs(); 359 clear_pcb_flags(pcb, PCB_DBREGS); 360 } 361 } 362 363 void 364 cpu_thread_clean(struct thread *td) 365 { 366 struct pcb *pcb; 367 368 pcb = td->td_pcb; 369 370 /* 371 * Clean TSS/iomap 372 */ 373 if (pcb->pcb_tssp != NULL) { 374 pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp, 375 (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1)); 376 kmem_free(pcb->pcb_tssp, ctob(IOPAGES + 1)); 377 pcb->pcb_tssp = NULL; 378 } 379 } 380 381 void 382 cpu_thread_swapin(struct thread *td) 383 { 384 } 385 386 void 387 cpu_thread_swapout(struct thread *td) 388 { 389 } 390 391 void 392 cpu_thread_alloc(struct thread *td) 393 { 394 struct pcb *pcb; 395 struct xstate_hdr *xhdr; 396 397 set_top_of_stack_td(td); 398 td->td_pcb = pcb = get_pcb_td(td); 399 td->td_frame = (struct trapframe *)td->td_md.md_stack_base - 1; 400 td->td_md.md_usr_fpu_save = fpu_save_area_alloc(); 401 pcb->pcb_save = get_pcb_user_save_pcb(pcb); 402 if (use_xsave) { 403 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1); 404 bzero(xhdr, sizeof(*xhdr)); 405 xhdr->xstate_bv = xsave_mask; 406 } 407 } 408 409 void 410 cpu_thread_free(struct thread *td) 411 { 412 cpu_thread_clean(td); 413 414 fpu_save_area_free(td->td_md.md_usr_fpu_save); 415 td->td_md.md_usr_fpu_save = NULL; 416 } 417 418 bool 419 cpu_exec_vmspace_reuse(struct proc *p, vm_map_t map) 420 { 421 422 return (((curproc->p_md.md_flags & P_MD_KPTI) != 0) == 423 (vm_map_pmap(map)->pm_ucr3 != PMAP_NO_CR3)); 424 } 425 426 static void 427 cpu_procctl_kpti_ctl(struct proc *p, int val) 428 { 429 430 if (pti && val == PROC_KPTI_CTL_ENABLE_ON_EXEC) 431 p->p_md.md_flags |= P_MD_KPTI; 432 if (val == PROC_KPTI_CTL_DISABLE_ON_EXEC) 433 p->p_md.md_flags &= ~P_MD_KPTI; 434 } 435 436 static void 437 cpu_procctl_kpti_status(struct proc *p, int *val) 438 { 439 *val = (p->p_md.md_flags & P_MD_KPTI) != 0 ? 440 PROC_KPTI_CTL_ENABLE_ON_EXEC: 441 PROC_KPTI_CTL_DISABLE_ON_EXEC; 442 if (vmspace_pmap(p->p_vmspace)->pm_ucr3 != PMAP_NO_CR3) 443 *val |= PROC_KPTI_STATUS_ACTIVE; 444 } 445 446 static int 447 cpu_procctl_la_ctl(struct proc *p, int val) 448 { 449 int error; 450 451 error = 0; 452 switch (val) { 453 case PROC_LA_CTL_LA48_ON_EXEC: 454 p->p_md.md_flags |= P_MD_LA48; 455 p->p_md.md_flags &= ~P_MD_LA57; 456 break; 457 case PROC_LA_CTL_LA57_ON_EXEC: 458 if (la57) { 459 p->p_md.md_flags &= ~P_MD_LA48; 460 p->p_md.md_flags |= P_MD_LA57; 461 } else { 462 error = ENOTSUP; 463 } 464 break; 465 case PROC_LA_CTL_DEFAULT_ON_EXEC: 466 p->p_md.md_flags &= ~(P_MD_LA48 | P_MD_LA57); 467 break; 468 } 469 return (error); 470 } 471 472 static void 473 cpu_procctl_la_status(struct proc *p, int *val) 474 { 475 int res; 476 477 if ((p->p_md.md_flags & P_MD_LA48) != 0) 478 res = PROC_LA_CTL_LA48_ON_EXEC; 479 else if ((p->p_md.md_flags & P_MD_LA57) != 0) 480 res = PROC_LA_CTL_LA57_ON_EXEC; 481 else 482 res = PROC_LA_CTL_DEFAULT_ON_EXEC; 483 if (p->p_sysent->sv_maxuser == VM_MAXUSER_ADDRESS_LA48) 484 res |= PROC_LA_STATUS_LA48; 485 else 486 res |= PROC_LA_STATUS_LA57; 487 *val = res; 488 } 489 490 int 491 cpu_procctl(struct thread *td, int idtype, id_t id, int com, void *data) 492 { 493 struct proc *p; 494 int error, val; 495 496 switch (com) { 497 case PROC_KPTI_CTL: 498 case PROC_KPTI_STATUS: 499 case PROC_LA_CTL: 500 case PROC_LA_STATUS: 501 if (idtype != P_PID) { 502 error = EINVAL; 503 break; 504 } 505 if (com == PROC_KPTI_CTL) { 506 /* sad but true and not a joke */ 507 error = priv_check(td, PRIV_IO); 508 if (error != 0) 509 break; 510 } 511 if (com == PROC_KPTI_CTL || com == PROC_LA_CTL) { 512 error = copyin(data, &val, sizeof(val)); 513 if (error != 0) 514 break; 515 } 516 if (com == PROC_KPTI_CTL && 517 val != PROC_KPTI_CTL_ENABLE_ON_EXEC && 518 val != PROC_KPTI_CTL_DISABLE_ON_EXEC) { 519 error = EINVAL; 520 break; 521 } 522 if (com == PROC_LA_CTL && 523 val != PROC_LA_CTL_LA48_ON_EXEC && 524 val != PROC_LA_CTL_LA57_ON_EXEC && 525 val != PROC_LA_CTL_DEFAULT_ON_EXEC) { 526 error = EINVAL; 527 break; 528 } 529 error = pget(id, PGET_CANSEE | PGET_NOTWEXIT | PGET_NOTID, &p); 530 if (error != 0) 531 break; 532 switch (com) { 533 case PROC_KPTI_CTL: 534 cpu_procctl_kpti_ctl(p, val); 535 break; 536 case PROC_KPTI_STATUS: 537 cpu_procctl_kpti_status(p, &val); 538 break; 539 case PROC_LA_CTL: 540 error = cpu_procctl_la_ctl(p, val); 541 break; 542 case PROC_LA_STATUS: 543 cpu_procctl_la_status(p, &val); 544 break; 545 } 546 PROC_UNLOCK(p); 547 if (com == PROC_KPTI_STATUS || com == PROC_LA_STATUS) 548 error = copyout(&val, data, sizeof(val)); 549 break; 550 default: 551 error = EINVAL; 552 break; 553 } 554 return (error); 555 } 556 557 void 558 cpu_set_syscall_retval(struct thread *td, int error) 559 { 560 struct trapframe *frame; 561 562 frame = td->td_frame; 563 if (__predict_true(error == 0)) { 564 frame->tf_rax = td->td_retval[0]; 565 frame->tf_rdx = td->td_retval[1]; 566 frame->tf_rflags &= ~PSL_C; 567 return; 568 } 569 570 switch (error) { 571 case ERESTART: 572 /* 573 * Reconstruct pc, we know that 'syscall' is 2 bytes, 574 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 575 * We saved this in tf_err. 576 * %r10 (which was holding the value of %rcx) is restored 577 * for the next iteration. 578 * %r10 restore is only required for freebsd/amd64 processes, 579 * but shall be innocent for any ia32 ABI. 580 * 581 * Require full context restore to get the arguments 582 * in the registers reloaded at return to usermode. 583 */ 584 frame->tf_rip -= frame->tf_err; 585 frame->tf_r10 = frame->tf_rcx; 586 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 587 break; 588 589 case EJUSTRETURN: 590 break; 591 592 default: 593 frame->tf_rax = error; 594 frame->tf_rflags |= PSL_C; 595 break; 596 } 597 } 598 599 /* 600 * Initialize machine state, mostly pcb and trap frame for a new 601 * thread, about to return to userspace. Put enough state in the new 602 * thread's PCB to get it to go back to the fork_return(), which 603 * finalizes the thread state and handles peculiarities of the first 604 * return to userspace for the new thread. 605 */ 606 void 607 cpu_copy_thread(struct thread *td, struct thread *td0) 608 { 609 copy_thread(td0, td); 610 611 set_pcb_flags_raw(td->td_pcb, PCB_FULL_IRET); 612 } 613 614 /* 615 * Set that machine state for performing an upcall that starts 616 * the entry function with the given argument. 617 */ 618 void 619 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 620 stack_t *stack) 621 { 622 623 /* 624 * Do any extra cleaning that needs to be done. 625 * The thread may have optional components 626 * that are not present in a fresh thread. 627 * This may be a recycled thread so make it look 628 * as though it's newly allocated. 629 */ 630 cpu_thread_clean(td); 631 632 #ifdef COMPAT_FREEBSD32 633 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 634 /* 635 * Set the trap frame to point at the beginning of the entry 636 * function. 637 */ 638 td->td_frame->tf_rbp = 0; 639 td->td_frame->tf_rsp = 640 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 641 td->td_frame->tf_rip = (uintptr_t)entry; 642 643 /* Return address sentinel value to stop stack unwinding. */ 644 suword32((void *)td->td_frame->tf_rsp, 0); 645 646 /* Pass the argument to the entry point. */ 647 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 648 (uint32_t)(uintptr_t)arg); 649 650 return; 651 } 652 #endif 653 654 /* 655 * Set the trap frame to point at the beginning of the uts 656 * function. 657 */ 658 td->td_frame->tf_rbp = 0; 659 td->td_frame->tf_rsp = 660 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; 661 td->td_frame->tf_rsp -= 8; 662 td->td_frame->tf_rip = (register_t)entry; 663 td->td_frame->tf_ds = _udatasel; 664 td->td_frame->tf_es = _udatasel; 665 td->td_frame->tf_fs = _ufssel; 666 td->td_frame->tf_gs = _ugssel; 667 td->td_frame->tf_flags = TF_HASSEGS; 668 669 /* Return address sentinel value to stop stack unwinding. */ 670 suword((void *)td->td_frame->tf_rsp, 0); 671 672 /* Pass the argument to the entry point. */ 673 td->td_frame->tf_rdi = (register_t)arg; 674 } 675 676 int 677 cpu_set_user_tls(struct thread *td, void *tls_base) 678 { 679 struct pcb *pcb; 680 681 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 682 return (EINVAL); 683 684 pcb = td->td_pcb; 685 set_pcb_flags(pcb, PCB_FULL_IRET); 686 #ifdef COMPAT_FREEBSD32 687 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 688 pcb->pcb_gsbase = (register_t)tls_base; 689 return (0); 690 } 691 #endif 692 pcb->pcb_fsbase = (register_t)tls_base; 693 return (0); 694 } 695