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 /* 174 * Set registers for trampoline to user mode. Leave space for the 175 * return address on stack. These are the kernel mode register values. 176 */ 177 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */ 178 pcb2->pcb_rbp = 0; 179 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *); 180 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */ 181 pcb2->pcb_rip = (register_t)fork_trampoline; 182 /*- 183 * pcb2->pcb_dr*: cloned above. 184 * pcb2->pcb_savefpu: cloned above. 185 * pcb2->pcb_flags: cloned above. 186 * pcb2->pcb_onfault: cloned above (always NULL here?). 187 * pcb2->pcb_[fg]sbase: cloned above 188 */ 189 190 pcb2->pcb_tssp = NULL; 191 192 /* Setup to release spin count in fork_exit(). */ 193 td2->td_md.md_spinlock_count = 1; 194 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 195 pmap_thread_init_invl_gen(td2); 196 197 /* 198 * Copy the trap frame for the return to user mode as if from a syscall. 199 * This copies most of the user mode register values. Some of these 200 * registers are rewritten by cpu_set_upcall() and linux_set_upcall(). 201 */ 202 if ((td1->td_proc->p_flag & P_KPROC) == 0) { 203 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 204 205 /* 206 * If the current thread has the trap bit set (i.e. a debugger 207 * had single stepped the process to the system call), we need 208 * to clear the trap flag from the new frame. Otherwise, the new 209 * thread will receive a (likely unexpected) SIGTRAP when it 210 * executes the first instruction after returning to userland. 211 */ 212 td2->td_frame->tf_rflags &= ~PSL_T; 213 } 214 } 215 216 /* 217 * Finish a fork operation, with process p2 nearly set up. 218 * Copy and update the pcb, set up the stack so that the child 219 * ready to run and return to user mode. 220 */ 221 void 222 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 223 { 224 struct proc *p1; 225 struct pcb *pcb2; 226 struct mdproc *mdp1, *mdp2; 227 struct proc_ldt *pldt; 228 229 p1 = td1->td_proc; 230 if ((flags & RFPROC) == 0) { 231 if ((flags & RFMEM) == 0) { 232 /* unshare user LDT */ 233 mdp1 = &p1->p_md; 234 mtx_lock(&dt_lock); 235 if ((pldt = mdp1->md_ldt) != NULL && 236 pldt->ldt_refcnt > 1 && 237 user_ldt_alloc(p1, 1) == NULL) 238 panic("could not copy LDT"); 239 mtx_unlock(&dt_lock); 240 } 241 return; 242 } 243 244 /* Point the stack and pcb to the actual location */ 245 set_top_of_stack_td(td2); 246 td2->td_pcb = pcb2 = get_pcb_td(td2); 247 248 copy_thread(td1, td2); 249 250 /* Reset debug registers in the new process */ 251 x86_clear_dbregs(pcb2); 252 253 /* Point mdproc and then copy over p1's contents */ 254 mdp2 = &p2->p_md; 255 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 256 257 /* Set child return values. */ 258 p2->p_sysent->sv_set_fork_retval(td2); 259 260 /* As on i386, do not copy io permission bitmap. */ 261 pcb2->pcb_tssp = NULL; 262 263 /* New segment registers. */ 264 set_pcb_flags_raw(pcb2, PCB_FULL_IRET); 265 266 /* Copy the LDT, if necessary. */ 267 mdp1 = &td1->td_proc->p_md; 268 mdp2 = &p2->p_md; 269 if (mdp1->md_ldt == NULL) { 270 mdp2->md_ldt = NULL; 271 return; 272 } 273 mtx_lock(&dt_lock); 274 if (mdp1->md_ldt != NULL) { 275 if (flags & RFMEM) { 276 mdp1->md_ldt->ldt_refcnt++; 277 mdp2->md_ldt = mdp1->md_ldt; 278 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct 279 system_segment_descriptor)); 280 } else { 281 mdp2->md_ldt = NULL; 282 mdp2->md_ldt = user_ldt_alloc(p2, 0); 283 if (mdp2->md_ldt == NULL) 284 panic("could not copy LDT"); 285 amd64_set_ldt_data(td2, 0, max_ldt_segment, 286 (struct user_segment_descriptor *) 287 mdp1->md_ldt->ldt_base); 288 } 289 } else 290 mdp2->md_ldt = NULL; 291 mtx_unlock(&dt_lock); 292 293 /* 294 * Now, cpu_switch() can schedule the new process. 295 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 296 * containing the return address when exiting cpu_switch. 297 * This will normally be to fork_trampoline(), which will have 298 * %rbx loaded with the new proc's pointer. fork_trampoline() 299 * will set up a stack to call fork_return(p, frame); to complete 300 * the return to user-mode. 301 */ 302 } 303 304 void 305 x86_set_fork_retval(struct thread *td) 306 { 307 struct trapframe *frame = td->td_frame; 308 309 frame->tf_rax = 0; /* Child returns zero */ 310 frame->tf_rflags &= ~PSL_C; /* success */ 311 frame->tf_rdx = 1; /* System V emulation */ 312 } 313 314 /* 315 * Intercept the return address from a freshly forked process that has NOT 316 * been scheduled yet. 317 * 318 * This is needed to make kernel threads stay in kernel mode. 319 */ 320 void 321 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 322 { 323 /* 324 * Note that the trap frame follows the args, so the function 325 * is really called like this: func(arg, frame); 326 */ 327 td->td_pcb->pcb_r12 = (long) func; /* function */ 328 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 329 } 330 331 void 332 cpu_exit(struct thread *td) 333 { 334 335 /* 336 * If this process has a custom LDT, release it. 337 */ 338 if (td->td_proc->p_md.md_ldt != NULL) 339 user_ldt_free(td); 340 } 341 342 void 343 cpu_thread_exit(struct thread *td) 344 { 345 struct pcb *pcb; 346 347 critical_enter(); 348 if (td == PCPU_GET(fpcurthread)) 349 fpudrop(); 350 critical_exit(); 351 352 pcb = td->td_pcb; 353 354 /* Disable any hardware breakpoints. */ 355 if (pcb->pcb_flags & PCB_DBREGS) { 356 reset_dbregs(); 357 clear_pcb_flags(pcb, PCB_DBREGS); 358 } 359 } 360 361 void 362 cpu_thread_clean(struct thread *td) 363 { 364 struct pcb *pcb; 365 366 pcb = td->td_pcb; 367 368 /* 369 * Clean TSS/iomap 370 */ 371 if (pcb->pcb_tssp != NULL) { 372 pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp, 373 (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1)); 374 kmem_free((vm_offset_t)pcb->pcb_tssp, ctob(IOPAGES + 1)); 375 pcb->pcb_tssp = NULL; 376 } 377 } 378 379 void 380 cpu_thread_swapin(struct thread *td) 381 { 382 } 383 384 void 385 cpu_thread_swapout(struct thread *td) 386 { 387 } 388 389 void 390 cpu_thread_alloc(struct thread *td) 391 { 392 struct pcb *pcb; 393 struct xstate_hdr *xhdr; 394 395 set_top_of_stack_td(td); 396 td->td_pcb = pcb = get_pcb_td(td); 397 td->td_frame = (struct trapframe *)td->td_md.md_stack_base - 1; 398 td->td_md.md_usr_fpu_save = fpu_save_area_alloc(); 399 pcb->pcb_save = get_pcb_user_save_pcb(pcb); 400 if (use_xsave) { 401 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1); 402 bzero(xhdr, sizeof(*xhdr)); 403 xhdr->xstate_bv = xsave_mask; 404 } 405 } 406 407 void 408 cpu_thread_free(struct thread *td) 409 { 410 cpu_thread_clean(td); 411 412 fpu_save_area_free(td->td_md.md_usr_fpu_save); 413 td->td_md.md_usr_fpu_save = NULL; 414 } 415 416 bool 417 cpu_exec_vmspace_reuse(struct proc *p, vm_map_t map) 418 { 419 420 return (((curproc->p_md.md_flags & P_MD_KPTI) != 0) == 421 (vm_map_pmap(map)->pm_ucr3 != PMAP_NO_CR3)); 422 } 423 424 static void 425 cpu_procctl_kpti_ctl(struct proc *p, int val) 426 { 427 428 if (pti && val == PROC_KPTI_CTL_ENABLE_ON_EXEC) 429 p->p_md.md_flags |= P_MD_KPTI; 430 if (val == PROC_KPTI_CTL_DISABLE_ON_EXEC) 431 p->p_md.md_flags &= ~P_MD_KPTI; 432 } 433 434 static void 435 cpu_procctl_kpti_status(struct proc *p, int *val) 436 { 437 *val = (p->p_md.md_flags & P_MD_KPTI) != 0 ? 438 PROC_KPTI_CTL_ENABLE_ON_EXEC: 439 PROC_KPTI_CTL_DISABLE_ON_EXEC; 440 if (vmspace_pmap(p->p_vmspace)->pm_ucr3 != PMAP_NO_CR3) 441 *val |= PROC_KPTI_STATUS_ACTIVE; 442 } 443 444 static int 445 cpu_procctl_la_ctl(struct proc *p, int val) 446 { 447 int error; 448 449 error = 0; 450 switch (val) { 451 case PROC_LA_CTL_LA48_ON_EXEC: 452 p->p_md.md_flags |= P_MD_LA48; 453 p->p_md.md_flags &= ~P_MD_LA57; 454 break; 455 case PROC_LA_CTL_LA57_ON_EXEC: 456 if (la57) { 457 p->p_md.md_flags &= ~P_MD_LA48; 458 p->p_md.md_flags |= P_MD_LA57; 459 } else { 460 error = ENOTSUP; 461 } 462 break; 463 case PROC_LA_CTL_DEFAULT_ON_EXEC: 464 p->p_md.md_flags &= ~(P_MD_LA48 | P_MD_LA57); 465 break; 466 } 467 return (error); 468 } 469 470 static void 471 cpu_procctl_la_status(struct proc *p, int *val) 472 { 473 int res; 474 475 if ((p->p_md.md_flags & P_MD_LA48) != 0) 476 res = PROC_LA_CTL_LA48_ON_EXEC; 477 else if ((p->p_md.md_flags & P_MD_LA57) != 0) 478 res = PROC_LA_CTL_LA57_ON_EXEC; 479 else 480 res = PROC_LA_CTL_DEFAULT_ON_EXEC; 481 if (p->p_sysent->sv_maxuser == VM_MAXUSER_ADDRESS_LA48) 482 res |= PROC_LA_STATUS_LA48; 483 else 484 res |= PROC_LA_STATUS_LA57; 485 *val = res; 486 } 487 488 int 489 cpu_procctl(struct thread *td, int idtype, id_t id, int com, void *data) 490 { 491 struct proc *p; 492 int error, val; 493 494 switch (com) { 495 case PROC_KPTI_CTL: 496 case PROC_KPTI_STATUS: 497 case PROC_LA_CTL: 498 case PROC_LA_STATUS: 499 if (idtype != P_PID) { 500 error = EINVAL; 501 break; 502 } 503 if (com == PROC_KPTI_CTL) { 504 /* sad but true and not a joke */ 505 error = priv_check(td, PRIV_IO); 506 if (error != 0) 507 break; 508 } 509 if (com == PROC_KPTI_CTL || com == PROC_LA_CTL) { 510 error = copyin(data, &val, sizeof(val)); 511 if (error != 0) 512 break; 513 } 514 if (com == PROC_KPTI_CTL && 515 val != PROC_KPTI_CTL_ENABLE_ON_EXEC && 516 val != PROC_KPTI_CTL_DISABLE_ON_EXEC) { 517 error = EINVAL; 518 break; 519 } 520 if (com == PROC_LA_CTL && 521 val != PROC_LA_CTL_LA48_ON_EXEC && 522 val != PROC_LA_CTL_LA57_ON_EXEC && 523 val != PROC_LA_CTL_DEFAULT_ON_EXEC) { 524 error = EINVAL; 525 break; 526 } 527 error = pget(id, PGET_CANSEE | PGET_NOTWEXIT | PGET_NOTID, &p); 528 if (error != 0) 529 break; 530 switch (com) { 531 case PROC_KPTI_CTL: 532 cpu_procctl_kpti_ctl(p, val); 533 break; 534 case PROC_KPTI_STATUS: 535 cpu_procctl_kpti_status(p, &val); 536 break; 537 case PROC_LA_CTL: 538 error = cpu_procctl_la_ctl(p, val); 539 break; 540 case PROC_LA_STATUS: 541 cpu_procctl_la_status(p, &val); 542 break; 543 } 544 PROC_UNLOCK(p); 545 if (com == PROC_KPTI_STATUS || com == PROC_LA_STATUS) 546 error = copyout(&val, data, sizeof(val)); 547 break; 548 default: 549 error = EINVAL; 550 break; 551 } 552 return (error); 553 } 554 555 void 556 cpu_set_syscall_retval(struct thread *td, int error) 557 { 558 struct trapframe *frame; 559 560 frame = td->td_frame; 561 if (__predict_true(error == 0)) { 562 frame->tf_rax = td->td_retval[0]; 563 frame->tf_rdx = td->td_retval[1]; 564 frame->tf_rflags &= ~PSL_C; 565 return; 566 } 567 568 switch (error) { 569 case ERESTART: 570 /* 571 * Reconstruct pc, we know that 'syscall' is 2 bytes, 572 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 573 * We saved this in tf_err. 574 * %r10 (which was holding the value of %rcx) is restored 575 * for the next iteration. 576 * %r10 restore is only required for freebsd/amd64 processes, 577 * but shall be innocent for any ia32 ABI. 578 * 579 * Require full context restore to get the arguments 580 * in the registers reloaded at return to usermode. 581 */ 582 frame->tf_rip -= frame->tf_err; 583 frame->tf_r10 = frame->tf_rcx; 584 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 585 break; 586 587 case EJUSTRETURN: 588 break; 589 590 default: 591 frame->tf_rax = error; 592 frame->tf_rflags |= PSL_C; 593 break; 594 } 595 } 596 597 /* 598 * Initialize machine state, mostly pcb and trap frame for a new 599 * thread, about to return to userspace. Put enough state in the new 600 * thread's PCB to get it to go back to the fork_return(), which 601 * finalizes the thread state and handles peculiarities of the first 602 * return to userspace for the new thread. 603 */ 604 void 605 cpu_copy_thread(struct thread *td, struct thread *td0) 606 { 607 copy_thread(td0, td); 608 609 set_pcb_flags_raw(td->td_pcb, PCB_FULL_IRET); 610 } 611 612 /* 613 * Set that machine state for performing an upcall that starts 614 * the entry function with the given argument. 615 */ 616 void 617 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 618 stack_t *stack) 619 { 620 621 /* 622 * Do any extra cleaning that needs to be done. 623 * The thread may have optional components 624 * that are not present in a fresh thread. 625 * This may be a recycled thread so make it look 626 * as though it's newly allocated. 627 */ 628 cpu_thread_clean(td); 629 630 #ifdef COMPAT_FREEBSD32 631 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 632 /* 633 * Set the trap frame to point at the beginning of the entry 634 * function. 635 */ 636 td->td_frame->tf_rbp = 0; 637 td->td_frame->tf_rsp = 638 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 639 td->td_frame->tf_rip = (uintptr_t)entry; 640 641 /* Return address sentinel value to stop stack unwinding. */ 642 suword32((void *)td->td_frame->tf_rsp, 0); 643 644 /* Pass the argument to the entry point. */ 645 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 646 (uint32_t)(uintptr_t)arg); 647 648 return; 649 } 650 #endif 651 652 /* 653 * Set the trap frame to point at the beginning of the uts 654 * function. 655 */ 656 td->td_frame->tf_rbp = 0; 657 td->td_frame->tf_rsp = 658 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; 659 td->td_frame->tf_rsp -= 8; 660 td->td_frame->tf_rip = (register_t)entry; 661 td->td_frame->tf_ds = _udatasel; 662 td->td_frame->tf_es = _udatasel; 663 td->td_frame->tf_fs = _ufssel; 664 td->td_frame->tf_gs = _ugssel; 665 td->td_frame->tf_flags = TF_HASSEGS; 666 667 /* Return address sentinel value to stop stack unwinding. */ 668 suword((void *)td->td_frame->tf_rsp, 0); 669 670 /* Pass the argument to the entry point. */ 671 td->td_frame->tf_rdi = (register_t)arg; 672 } 673 674 int 675 cpu_set_user_tls(struct thread *td, void *tls_base) 676 { 677 struct pcb *pcb; 678 679 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 680 return (EINVAL); 681 682 pcb = td->td_pcb; 683 set_pcb_flags(pcb, PCB_FULL_IRET); 684 #ifdef COMPAT_FREEBSD32 685 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 686 pcb->pcb_gsbase = (register_t)tls_base; 687 return (0); 688 } 689 #endif 690 pcb->pcb_fsbase = (register_t)tls_base; 691 return (0); 692 } 693