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 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 41 */ 42 43 #include <sys/cdefs.h> 44 #include "opt_isa.h" 45 #include "opt_cpu.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/kernel.h> 52 #include <sys/ktr.h> 53 #include <sys/lock.h> 54 #include <sys/malloc.h> 55 #include <sys/mbuf.h> 56 #include <sys/mutex.h> 57 #include <sys/priv.h> 58 #include <sys/proc.h> 59 #include <sys/procctl.h> 60 #include <sys/smp.h> 61 #include <sys/sysctl.h> 62 #include <sys/sysent.h> 63 #include <sys/unistd.h> 64 #include <sys/vnode.h> 65 #include <sys/vmmeter.h> 66 #include <sys/wait.h> 67 68 #include <machine/cpu.h> 69 #include <machine/md_var.h> 70 #include <machine/pcb.h> 71 #include <machine/smp.h> 72 #include <machine/specialreg.h> 73 #include <machine/tss.h> 74 75 #include <vm/vm.h> 76 #include <vm/vm_extern.h> 77 #include <vm/vm_kern.h> 78 #include <vm/vm_page.h> 79 #include <vm/vm_map.h> 80 #include <vm/vm_param.h> 81 82 _Static_assert(OFFSETOF_MONITORBUF == offsetof(struct pcpu, pc_monitorbuf), 83 "OFFSETOF_MONITORBUF does not correspond with offset of pc_monitorbuf."); 84 85 void 86 set_top_of_stack_td(struct thread *td) 87 { 88 td->td_md.md_stack_base = td->td_kstack + 89 td->td_kstack_pages * PAGE_SIZE; 90 } 91 92 struct savefpu * 93 get_pcb_user_save_td(struct thread *td) 94 { 95 KASSERT(((vm_offset_t)td->td_md.md_usr_fpu_save % 96 XSAVE_AREA_ALIGN) == 0, 97 ("Unaligned pcb_user_save area ptr %p td %p", 98 td->td_md.md_usr_fpu_save, td)); 99 return (td->td_md.md_usr_fpu_save); 100 } 101 102 struct pcb * 103 get_pcb_td(struct thread *td) 104 { 105 106 return (&td->td_md.md_pcb); 107 } 108 109 struct savefpu * 110 get_pcb_user_save_pcb(struct pcb *pcb) 111 { 112 struct thread *td; 113 114 td = __containerof(pcb, struct thread, td_md.md_pcb); 115 return (get_pcb_user_save_td(td)); 116 } 117 118 void * 119 alloc_fpusave(int flags) 120 { 121 void *res; 122 struct savefpu_ymm *sf; 123 124 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags); 125 if (use_xsave) { 126 sf = (struct savefpu_ymm *)res; 127 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd)); 128 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask; 129 } 130 return (res); 131 } 132 133 /* 134 * Common code shared between cpu_fork() and cpu_copy_thread() for 135 * initializing a thread. 136 */ 137 static void 138 copy_thread(struct thread *td1, struct thread *td2) 139 { 140 struct pcb *pcb2; 141 142 pcb2 = td2->td_pcb; 143 144 /* Ensure that td1's pcb is up to date for user threads. */ 145 if ((td2->td_pflags & TDP_KTHREAD) == 0) { 146 MPASS(td1 == curthread); 147 fpuexit(td1); 148 update_pcb_bases(td1->td_pcb); 149 } 150 151 /* Copy td1's pcb */ 152 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 153 154 /* Properly initialize pcb_save */ 155 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 156 157 /* Kernel threads start with clean FPU and segment bases. */ 158 if ((td2->td_pflags & TDP_KTHREAD) != 0) { 159 pcb2->pcb_fsbase = 0; 160 pcb2->pcb_gsbase = 0; 161 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE | 162 PCB_KERNFPU | PCB_KERNFPU_THR); 163 } else { 164 MPASS((pcb2->pcb_flags & (PCB_KERNFPU | PCB_KERNFPU_THR)) == 0); 165 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2), 166 cpu_max_ext_state_size); 167 } 168 169 td2->td_frame = (struct trapframe *)td2->td_md.md_stack_base - 1; 170 171 /* 172 * Set registers for trampoline to user mode. Leave space for the 173 * return address on stack. These are the kernel mode register values. 174 */ 175 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */ 176 pcb2->pcb_rbp = 0; 177 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *); 178 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */ 179 pcb2->pcb_rip = (register_t)fork_trampoline; 180 /*- 181 * pcb2->pcb_dr*: cloned above. 182 * pcb2->pcb_savefpu: cloned above. 183 * pcb2->pcb_flags: cloned above. 184 * pcb2->pcb_onfault: cloned above (always NULL here?). 185 * pcb2->pcb_[fg]sbase: cloned above 186 */ 187 188 pcb2->pcb_tssp = NULL; 189 190 /* Setup to release spin count in fork_exit(). */ 191 td2->td_md.md_spinlock_count = 1; 192 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 193 pmap_thread_init_invl_gen(td2); 194 195 /* 196 * Copy the trap frame for the return to user mode as if from a syscall. 197 * This copies most of the user mode register values. Some of these 198 * registers are rewritten by cpu_set_upcall() and linux_set_upcall(). 199 */ 200 if ((td1->td_proc->p_flag & P_KPROC) == 0) { 201 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 202 203 /* 204 * If the current thread has the trap bit set (i.e. a debugger 205 * had single stepped the process to the system call), we need 206 * to clear the trap flag from the new frame. Otherwise, the new 207 * thread will receive a (likely unexpected) SIGTRAP when it 208 * executes the first instruction after returning to userland. 209 */ 210 td2->td_frame->tf_rflags &= ~PSL_T; 211 } 212 } 213 214 /* 215 * Finish a fork operation, with process p2 nearly set up. 216 * Copy and update the pcb, set up the stack so that the child 217 * ready to run and return to user mode. 218 */ 219 void 220 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 221 { 222 struct proc *p1; 223 struct pcb *pcb2; 224 struct mdproc *mdp1, *mdp2; 225 struct proc_ldt *pldt; 226 227 p1 = td1->td_proc; 228 if ((flags & RFPROC) == 0) { 229 if ((flags & RFMEM) == 0) { 230 /* unshare user LDT */ 231 mdp1 = &p1->p_md; 232 mtx_lock(&dt_lock); 233 if ((pldt = mdp1->md_ldt) != NULL && 234 pldt->ldt_refcnt > 1 && 235 user_ldt_alloc(p1, 1) == NULL) 236 panic("could not copy LDT"); 237 mtx_unlock(&dt_lock); 238 } 239 return; 240 } 241 242 /* Point the stack and pcb to the actual location */ 243 set_top_of_stack_td(td2); 244 td2->td_pcb = pcb2 = get_pcb_td(td2); 245 246 copy_thread(td1, td2); 247 248 /* Reset debug registers in the new process */ 249 x86_clear_dbregs(pcb2); 250 251 /* Point mdproc and then copy over p1's contents */ 252 mdp2 = &p2->p_md; 253 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 254 255 /* Set child return values. */ 256 p2->p_sysent->sv_set_fork_retval(td2); 257 258 /* As on i386, do not copy io permission bitmap. */ 259 pcb2->pcb_tssp = NULL; 260 261 /* New segment registers. */ 262 set_pcb_flags_raw(pcb2, PCB_FULL_IRET); 263 264 /* Copy the LDT, if necessary. */ 265 mdp1 = &td1->td_proc->p_md; 266 mdp2 = &p2->p_md; 267 if (mdp1->md_ldt == NULL) { 268 mdp2->md_ldt = NULL; 269 return; 270 } 271 mtx_lock(&dt_lock); 272 if (mdp1->md_ldt != NULL) { 273 if (flags & RFMEM) { 274 mdp1->md_ldt->ldt_refcnt++; 275 mdp2->md_ldt = mdp1->md_ldt; 276 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct 277 system_segment_descriptor)); 278 } else { 279 mdp2->md_ldt = NULL; 280 mdp2->md_ldt = user_ldt_alloc(p2, 0); 281 if (mdp2->md_ldt == NULL) 282 panic("could not copy LDT"); 283 amd64_set_ldt_data(td2, 0, max_ldt_segment, 284 (struct user_segment_descriptor *) 285 mdp1->md_ldt->ldt_base); 286 } 287 } else 288 mdp2->md_ldt = NULL; 289 mtx_unlock(&dt_lock); 290 291 /* 292 * Now, cpu_switch() can schedule the new process. 293 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 294 * containing the return address when exiting cpu_switch. 295 * This will normally be to fork_trampoline(), which will have 296 * %rbx loaded with the new proc's pointer. fork_trampoline() 297 * will set up a stack to call fork_return(p, frame); to complete 298 * the return to user-mode. 299 */ 300 } 301 302 void 303 x86_set_fork_retval(struct thread *td) 304 { 305 struct trapframe *frame = td->td_frame; 306 307 frame->tf_rax = 0; /* Child returns zero */ 308 frame->tf_rflags &= ~PSL_C; /* success */ 309 frame->tf_rdx = 1; /* System V emulation */ 310 } 311 312 /* 313 * Intercept the return address from a freshly forked process that has NOT 314 * been scheduled yet. 315 * 316 * This is needed to make kernel threads stay in kernel mode. 317 */ 318 void 319 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 320 { 321 /* 322 * Note that the trap frame follows the args, so the function 323 * is really called like this: func(arg, frame); 324 */ 325 td->td_pcb->pcb_r12 = (long) func; /* function */ 326 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 327 } 328 329 void 330 cpu_exit(struct thread *td) 331 { 332 333 /* 334 * If this process has a custom LDT, release it. 335 */ 336 if (td->td_proc->p_md.md_ldt != NULL) 337 user_ldt_free(td); 338 } 339 340 void 341 cpu_thread_exit(struct thread *td) 342 { 343 struct pcb *pcb; 344 345 critical_enter(); 346 if (td == PCPU_GET(fpcurthread)) 347 fpudrop(); 348 critical_exit(); 349 350 pcb = td->td_pcb; 351 352 /* Disable any hardware breakpoints. */ 353 if (pcb->pcb_flags & PCB_DBREGS) { 354 reset_dbregs(); 355 clear_pcb_flags(pcb, PCB_DBREGS); 356 } 357 } 358 359 void 360 cpu_thread_clean(struct thread *td) 361 { 362 struct pcb *pcb; 363 364 pcb = td->td_pcb; 365 366 /* 367 * Clean TSS/iomap 368 */ 369 if (pcb->pcb_tssp != NULL) { 370 pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp, 371 (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1)); 372 kmem_free(pcb->pcb_tssp, ctob(IOPAGES + 1)); 373 pcb->pcb_tssp = NULL; 374 } 375 } 376 377 void 378 cpu_thread_swapin(struct thread *td) 379 { 380 } 381 382 void 383 cpu_thread_swapout(struct thread *td) 384 { 385 } 386 387 void 388 cpu_thread_alloc(struct thread *td) 389 { 390 struct pcb *pcb; 391 struct xstate_hdr *xhdr; 392 393 set_top_of_stack_td(td); 394 td->td_pcb = pcb = get_pcb_td(td); 395 td->td_frame = (struct trapframe *)td->td_md.md_stack_base - 1; 396 td->td_md.md_usr_fpu_save = fpu_save_area_alloc(); 397 pcb->pcb_save = get_pcb_user_save_pcb(pcb); 398 if (use_xsave) { 399 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1); 400 bzero(xhdr, sizeof(*xhdr)); 401 xhdr->xstate_bv = xsave_mask; 402 } 403 } 404 405 void 406 cpu_thread_free(struct thread *td) 407 { 408 cpu_thread_clean(td); 409 410 fpu_save_area_free(td->td_md.md_usr_fpu_save); 411 td->td_md.md_usr_fpu_save = NULL; 412 } 413 414 bool 415 cpu_exec_vmspace_reuse(struct proc *p, vm_map_t map) 416 { 417 418 return (((curproc->p_md.md_flags & P_MD_KPTI) != 0) == 419 (vm_map_pmap(map)->pm_ucr3 != PMAP_NO_CR3)); 420 } 421 422 static void 423 cpu_procctl_kpti_ctl(struct proc *p, int val) 424 { 425 426 if (pti && val == PROC_KPTI_CTL_ENABLE_ON_EXEC) 427 p->p_md.md_flags |= P_MD_KPTI; 428 if (val == PROC_KPTI_CTL_DISABLE_ON_EXEC) 429 p->p_md.md_flags &= ~P_MD_KPTI; 430 } 431 432 static void 433 cpu_procctl_kpti_status(struct proc *p, int *val) 434 { 435 *val = (p->p_md.md_flags & P_MD_KPTI) != 0 ? 436 PROC_KPTI_CTL_ENABLE_ON_EXEC: 437 PROC_KPTI_CTL_DISABLE_ON_EXEC; 438 if (vmspace_pmap(p->p_vmspace)->pm_ucr3 != PMAP_NO_CR3) 439 *val |= PROC_KPTI_STATUS_ACTIVE; 440 } 441 442 static int 443 cpu_procctl_la_ctl(struct proc *p, int val) 444 { 445 int error; 446 447 error = 0; 448 switch (val) { 449 case PROC_LA_CTL_LA48_ON_EXEC: 450 p->p_md.md_flags |= P_MD_LA48; 451 p->p_md.md_flags &= ~P_MD_LA57; 452 break; 453 case PROC_LA_CTL_LA57_ON_EXEC: 454 if (la57) { 455 p->p_md.md_flags &= ~P_MD_LA48; 456 p->p_md.md_flags |= P_MD_LA57; 457 } else { 458 error = ENOTSUP; 459 } 460 break; 461 case PROC_LA_CTL_DEFAULT_ON_EXEC: 462 p->p_md.md_flags &= ~(P_MD_LA48 | P_MD_LA57); 463 break; 464 } 465 return (error); 466 } 467 468 static void 469 cpu_procctl_la_status(struct proc *p, int *val) 470 { 471 int res; 472 473 if ((p->p_md.md_flags & P_MD_LA48) != 0) 474 res = PROC_LA_CTL_LA48_ON_EXEC; 475 else if ((p->p_md.md_flags & P_MD_LA57) != 0) 476 res = PROC_LA_CTL_LA57_ON_EXEC; 477 else 478 res = PROC_LA_CTL_DEFAULT_ON_EXEC; 479 if (p->p_sysent->sv_maxuser == VM_MAXUSER_ADDRESS_LA48) 480 res |= PROC_LA_STATUS_LA48; 481 else 482 res |= PROC_LA_STATUS_LA57; 483 *val = res; 484 } 485 486 int 487 cpu_procctl(struct thread *td, int idtype, id_t id, int com, void *data) 488 { 489 struct proc *p; 490 int error, val; 491 492 switch (com) { 493 case PROC_KPTI_CTL: 494 case PROC_KPTI_STATUS: 495 case PROC_LA_CTL: 496 case PROC_LA_STATUS: 497 if (idtype != P_PID) { 498 error = EINVAL; 499 break; 500 } 501 if (com == PROC_KPTI_CTL) { 502 /* sad but true and not a joke */ 503 error = priv_check(td, PRIV_IO); 504 if (error != 0) 505 break; 506 } 507 if (com == PROC_KPTI_CTL || com == PROC_LA_CTL) { 508 error = copyin(data, &val, sizeof(val)); 509 if (error != 0) 510 break; 511 } 512 if (com == PROC_KPTI_CTL && 513 val != PROC_KPTI_CTL_ENABLE_ON_EXEC && 514 val != PROC_KPTI_CTL_DISABLE_ON_EXEC) { 515 error = EINVAL; 516 break; 517 } 518 if (com == PROC_LA_CTL && 519 val != PROC_LA_CTL_LA48_ON_EXEC && 520 val != PROC_LA_CTL_LA57_ON_EXEC && 521 val != PROC_LA_CTL_DEFAULT_ON_EXEC) { 522 error = EINVAL; 523 break; 524 } 525 error = pget(id, PGET_CANSEE | PGET_NOTWEXIT | PGET_NOTID, &p); 526 if (error != 0) 527 break; 528 switch (com) { 529 case PROC_KPTI_CTL: 530 cpu_procctl_kpti_ctl(p, val); 531 break; 532 case PROC_KPTI_STATUS: 533 cpu_procctl_kpti_status(p, &val); 534 break; 535 case PROC_LA_CTL: 536 error = cpu_procctl_la_ctl(p, val); 537 break; 538 case PROC_LA_STATUS: 539 cpu_procctl_la_status(p, &val); 540 break; 541 } 542 PROC_UNLOCK(p); 543 if (com == PROC_KPTI_STATUS || com == PROC_LA_STATUS) 544 error = copyout(&val, data, sizeof(val)); 545 break; 546 default: 547 error = EINVAL; 548 break; 549 } 550 return (error); 551 } 552 553 void 554 cpu_set_syscall_retval(struct thread *td, int error) 555 { 556 struct trapframe *frame; 557 558 frame = td->td_frame; 559 if (__predict_true(error == 0)) { 560 frame->tf_rax = td->td_retval[0]; 561 frame->tf_rdx = td->td_retval[1]; 562 frame->tf_rflags &= ~PSL_C; 563 return; 564 } 565 566 switch (error) { 567 case ERESTART: 568 /* 569 * Reconstruct pc, we know that 'syscall' is 2 bytes, 570 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 571 * We saved this in tf_err. 572 * %r10 (which was holding the value of %rcx) is restored 573 * for the next iteration. 574 * %r10 restore is only required for freebsd/amd64 processes, 575 * but shall be innocent for any ia32 ABI. 576 * 577 * Require full context restore to get the arguments 578 * in the registers reloaded at return to usermode. 579 */ 580 frame->tf_rip -= frame->tf_err; 581 frame->tf_r10 = frame->tf_rcx; 582 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 583 break; 584 585 case EJUSTRETURN: 586 break; 587 588 default: 589 frame->tf_rax = error; 590 frame->tf_rflags |= PSL_C; 591 break; 592 } 593 } 594 595 /* 596 * Initialize machine state, mostly pcb and trap frame for a new 597 * thread, about to return to userspace. Put enough state in the new 598 * thread's PCB to get it to go back to the fork_return(), which 599 * finalizes the thread state and handles peculiarities of the first 600 * return to userspace for the new thread. 601 */ 602 void 603 cpu_copy_thread(struct thread *td, struct thread *td0) 604 { 605 copy_thread(td0, td); 606 607 set_pcb_flags_raw(td->td_pcb, PCB_FULL_IRET); 608 } 609 610 /* 611 * Set that machine state for performing an upcall that starts 612 * the entry function with the given argument. 613 */ 614 int 615 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 616 stack_t *stack) 617 { 618 619 /* 620 * Do any extra cleaning that needs to be done. 621 * The thread may have optional components 622 * that are not present in a fresh thread. 623 * This may be a recycled thread so make it look 624 * as though it's newly allocated. 625 */ 626 cpu_thread_clean(td); 627 628 #ifdef COMPAT_FREEBSD32 629 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 630 /* 631 * Set the trap frame to point at the beginning of the entry 632 * function. 633 */ 634 td->td_frame->tf_rbp = 0; 635 td->td_frame->tf_rsp = 636 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 637 td->td_frame->tf_rip = (uintptr_t)entry; 638 639 /* Return address sentinel value to stop stack unwinding. */ 640 if (suword32((void *)td->td_frame->tf_rsp, 0) != 0) 641 return (EFAULT); 642 643 /* Pass the argument to the entry point. */ 644 if (suword32( 645 (void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 646 (uint32_t)(uintptr_t)arg) != 0) 647 return (EFAULT); 648 return (0); 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 if (suword((void *)td->td_frame->tf_rsp, 0) != 0) 669 return (EFAULT); 670 671 /* Pass the argument to the entry point. */ 672 td->td_frame->tf_rdi = (register_t)arg; 673 674 return (0); 675 } 676 677 int 678 cpu_set_user_tls(struct thread *td, void *tls_base) 679 { 680 struct pcb *pcb; 681 682 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 683 return (EINVAL); 684 685 pcb = td->td_pcb; 686 set_pcb_flags(pcb, PCB_FULL_IRET); 687 #ifdef COMPAT_FREEBSD32 688 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 689 pcb->pcb_gsbase = (register_t)tls_base; 690 return (0); 691 } 692 #endif 693 pcb->pcb_fsbase = (register_t)tls_base; 694 return (0); 695 } 696