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 roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN); 95 } 96 97 struct savefpu * 98 get_pcb_user_save_td(struct thread *td) 99 { 100 vm_offset_t p; 101 102 p = td->td_md.md_stack_base; 103 KASSERT((p % XSAVE_AREA_ALIGN) == 0, 104 ("Unaligned pcb_user_save area ptr %#lx td %p", p, td)); 105 return ((struct savefpu *)p); 106 } 107 108 struct pcb * 109 get_pcb_td(struct thread *td) 110 { 111 112 return (&td->td_md.md_pcb); 113 } 114 115 struct savefpu * 116 get_pcb_user_save_pcb(struct pcb *pcb) 117 { 118 struct thread *td; 119 120 td = __containerof(pcb, struct thread, td_md.md_pcb); 121 return (get_pcb_user_save_td(td)); 122 } 123 124 void * 125 alloc_fpusave(int flags) 126 { 127 void *res; 128 struct savefpu_ymm *sf; 129 130 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags); 131 if (use_xsave) { 132 sf = (struct savefpu_ymm *)res; 133 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd)); 134 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask; 135 } 136 return (res); 137 } 138 139 /* 140 * Common code shared between cpu_fork() and cpu_copy_thread() for 141 * initializing a thread. 142 */ 143 static void 144 copy_thread(struct thread *td1, struct thread *td2) 145 { 146 struct pcb *pcb2; 147 148 pcb2 = td2->td_pcb; 149 150 /* Ensure that td1's pcb is up to date for user threads. */ 151 if ((td2->td_pflags & TDP_KTHREAD) == 0) { 152 MPASS(td1 == curthread); 153 fpuexit(td1); 154 update_pcb_bases(td1->td_pcb); 155 } 156 157 /* Copy td1's pcb */ 158 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 159 160 /* Properly initialize pcb_save */ 161 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 162 163 /* Kernel threads start with clean FPU and segment bases. */ 164 if ((td2->td_pflags & TDP_KTHREAD) != 0) { 165 pcb2->pcb_fsbase = 0; 166 pcb2->pcb_gsbase = 0; 167 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE | 168 PCB_KERNFPU | PCB_KERNFPU_THR); 169 } else { 170 MPASS((pcb2->pcb_flags & (PCB_KERNFPU | PCB_KERNFPU_THR)) == 0); 171 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2), 172 cpu_max_ext_state_size); 173 } 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 /* 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 /* 199 * Finish a fork operation, with process p2 nearly set up. 200 * Copy and update the pcb, set up the stack so that the child 201 * ready to run and return to user mode. 202 */ 203 void 204 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 205 { 206 struct proc *p1; 207 struct pcb *pcb2; 208 struct mdproc *mdp1, *mdp2; 209 struct proc_ldt *pldt; 210 211 p1 = td1->td_proc; 212 if ((flags & RFPROC) == 0) { 213 if ((flags & RFMEM) == 0) { 214 /* unshare user LDT */ 215 mdp1 = &p1->p_md; 216 mtx_lock(&dt_lock); 217 if ((pldt = mdp1->md_ldt) != NULL && 218 pldt->ldt_refcnt > 1 && 219 user_ldt_alloc(p1, 1) == NULL) 220 panic("could not copy LDT"); 221 mtx_unlock(&dt_lock); 222 } 223 return; 224 } 225 226 /* Point the stack and pcb to the actual location */ 227 set_top_of_stack_td(td2); 228 td2->td_pcb = pcb2 = get_pcb_td(td2); 229 230 copy_thread(td1, td2); 231 232 /* Reset debug registers in the new process */ 233 pcb2->pcb_dr0 = 0; 234 pcb2->pcb_dr1 = 0; 235 pcb2->pcb_dr2 = 0; 236 pcb2->pcb_dr3 = 0; 237 pcb2->pcb_dr6 = 0; 238 pcb2->pcb_dr7 = 0; 239 240 /* Point mdproc and then copy over p1's contents */ 241 mdp2 = &p2->p_md; 242 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 243 244 /* 245 * Copy the trap frame for the return to user mode as if from a 246 * syscall. This copies most of the user mode register values. 247 */ 248 td2->td_frame = (struct trapframe *)td2->td_md.md_stack_base - 1; 249 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 250 251 td2->td_frame->tf_rax = 0; /* Child returns zero */ 252 td2->td_frame->tf_rflags &= ~PSL_C; /* success */ 253 td2->td_frame->tf_rdx = 1; 254 255 /* 256 * If the parent process has the trap bit set (i.e. a debugger 257 * had single stepped the process to the system call), we need 258 * to clear the trap flag from the new frame. 259 */ 260 td2->td_frame->tf_rflags &= ~PSL_T; 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 /* 307 * Intercept the return address from a freshly forked process that has NOT 308 * been scheduled yet. 309 * 310 * This is needed to make kernel threads stay in kernel mode. 311 */ 312 void 313 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 314 { 315 /* 316 * Note that the trap frame follows the args, so the function 317 * is really called like this: func(arg, frame); 318 */ 319 td->td_pcb->pcb_r12 = (long) func; /* function */ 320 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 321 } 322 323 void 324 cpu_exit(struct thread *td) 325 { 326 327 /* 328 * If this process has a custom LDT, release it. 329 */ 330 if (td->td_proc->p_md.md_ldt != NULL) 331 user_ldt_free(td); 332 } 333 334 void 335 cpu_thread_exit(struct thread *td) 336 { 337 struct pcb *pcb; 338 339 critical_enter(); 340 if (td == PCPU_GET(fpcurthread)) 341 fpudrop(); 342 critical_exit(); 343 344 pcb = td->td_pcb; 345 346 /* Disable any hardware breakpoints. */ 347 if (pcb->pcb_flags & PCB_DBREGS) { 348 reset_dbregs(); 349 clear_pcb_flags(pcb, PCB_DBREGS); 350 } 351 } 352 353 void 354 cpu_thread_clean(struct thread *td) 355 { 356 struct pcb *pcb; 357 358 pcb = td->td_pcb; 359 360 /* 361 * Clean TSS/iomap 362 */ 363 if (pcb->pcb_tssp != NULL) { 364 pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp, 365 (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1)); 366 kmem_free((vm_offset_t)pcb->pcb_tssp, ctob(IOPAGES + 1)); 367 pcb->pcb_tssp = NULL; 368 } 369 } 370 371 void 372 cpu_thread_swapin(struct thread *td) 373 { 374 } 375 376 void 377 cpu_thread_swapout(struct thread *td) 378 { 379 } 380 381 void 382 cpu_thread_alloc(struct thread *td) 383 { 384 struct pcb *pcb; 385 struct xstate_hdr *xhdr; 386 387 set_top_of_stack_td(td); 388 td->td_pcb = pcb = get_pcb_td(td); 389 td->td_frame = (struct trapframe *)td->td_md.md_stack_base - 1; 390 pcb->pcb_save = get_pcb_user_save_pcb(pcb); 391 if (use_xsave) { 392 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1); 393 bzero(xhdr, sizeof(*xhdr)); 394 xhdr->xstate_bv = xsave_mask; 395 } 396 } 397 398 void 399 cpu_thread_free(struct thread *td) 400 { 401 402 cpu_thread_clean(td); 403 } 404 405 bool 406 cpu_exec_vmspace_reuse(struct proc *p, vm_map_t map) 407 { 408 409 return (((curproc->p_md.md_flags & P_MD_KPTI) != 0) == 410 (vm_map_pmap(map)->pm_ucr3 != PMAP_NO_CR3)); 411 } 412 413 static void 414 cpu_procctl_kpti_ctl(struct proc *p, int val) 415 { 416 417 if (pti && val == PROC_KPTI_CTL_ENABLE_ON_EXEC) 418 p->p_md.md_flags |= P_MD_KPTI; 419 if (val == PROC_KPTI_CTL_DISABLE_ON_EXEC) 420 p->p_md.md_flags &= ~P_MD_KPTI; 421 } 422 423 static void 424 cpu_procctl_kpti_status(struct proc *p, int *val) 425 { 426 *val = (p->p_md.md_flags & P_MD_KPTI) != 0 ? 427 PROC_KPTI_CTL_ENABLE_ON_EXEC: 428 PROC_KPTI_CTL_DISABLE_ON_EXEC; 429 if (vmspace_pmap(p->p_vmspace)->pm_ucr3 != PMAP_NO_CR3) 430 *val |= PROC_KPTI_STATUS_ACTIVE; 431 } 432 433 static int 434 cpu_procctl_la_ctl(struct proc *p, int val) 435 { 436 int error; 437 438 error = 0; 439 switch (val) { 440 case PROC_LA_CTL_LA48_ON_EXEC: 441 p->p_md.md_flags |= P_MD_LA48; 442 p->p_md.md_flags &= ~P_MD_LA57; 443 break; 444 case PROC_LA_CTL_LA57_ON_EXEC: 445 if (la57) { 446 p->p_md.md_flags &= ~P_MD_LA48; 447 p->p_md.md_flags |= P_MD_LA57; 448 } else { 449 error = ENOTSUP; 450 } 451 break; 452 case PROC_LA_CTL_DEFAULT_ON_EXEC: 453 p->p_md.md_flags &= ~(P_MD_LA48 | P_MD_LA57); 454 break; 455 } 456 return (error); 457 } 458 459 static void 460 cpu_procctl_la_status(struct proc *p, int *val) 461 { 462 int res; 463 464 if ((p->p_md.md_flags & P_MD_LA48) != 0) 465 res = PROC_LA_CTL_LA48_ON_EXEC; 466 else if ((p->p_md.md_flags & P_MD_LA57) != 0) 467 res = PROC_LA_CTL_LA57_ON_EXEC; 468 else 469 res = PROC_LA_CTL_DEFAULT_ON_EXEC; 470 if (p->p_sysent->sv_maxuser == VM_MAXUSER_ADDRESS_LA48) 471 res |= PROC_LA_STATUS_LA48; 472 else 473 res |= PROC_LA_STATUS_LA57; 474 *val = res; 475 } 476 477 int 478 cpu_procctl(struct thread *td, int idtype, id_t id, int com, void *data) 479 { 480 struct proc *p; 481 int error, val; 482 483 switch (com) { 484 case PROC_KPTI_CTL: 485 case PROC_KPTI_STATUS: 486 case PROC_LA_CTL: 487 case PROC_LA_STATUS: 488 if (idtype != P_PID) { 489 error = EINVAL; 490 break; 491 } 492 if (com == PROC_KPTI_CTL) { 493 /* sad but true and not a joke */ 494 error = priv_check(td, PRIV_IO); 495 if (error != 0) 496 break; 497 } 498 if (com == PROC_KPTI_CTL || com == PROC_LA_CTL) { 499 error = copyin(data, &val, sizeof(val)); 500 if (error != 0) 501 break; 502 } 503 if (com == PROC_KPTI_CTL && 504 val != PROC_KPTI_CTL_ENABLE_ON_EXEC && 505 val != PROC_KPTI_CTL_DISABLE_ON_EXEC) { 506 error = EINVAL; 507 break; 508 } 509 if (com == PROC_LA_CTL && 510 val != PROC_LA_CTL_LA48_ON_EXEC && 511 val != PROC_LA_CTL_LA57_ON_EXEC && 512 val != PROC_LA_CTL_DEFAULT_ON_EXEC) { 513 error = EINVAL; 514 break; 515 } 516 error = pget(id, PGET_CANSEE | PGET_NOTWEXIT | PGET_NOTID, &p); 517 if (error != 0) 518 break; 519 switch (com) { 520 case PROC_KPTI_CTL: 521 cpu_procctl_kpti_ctl(p, val); 522 break; 523 case PROC_KPTI_STATUS: 524 cpu_procctl_kpti_status(p, &val); 525 break; 526 case PROC_LA_CTL: 527 error = cpu_procctl_la_ctl(p, val); 528 break; 529 case PROC_LA_STATUS: 530 cpu_procctl_la_status(p, &val); 531 break; 532 } 533 PROC_UNLOCK(p); 534 if (com == PROC_KPTI_STATUS || com == PROC_LA_STATUS) 535 error = copyout(&val, data, sizeof(val)); 536 break; 537 default: 538 error = EINVAL; 539 break; 540 } 541 return (error); 542 } 543 544 void 545 cpu_set_syscall_retval(struct thread *td, int error) 546 { 547 struct trapframe *frame; 548 549 frame = td->td_frame; 550 if (__predict_true(error == 0)) { 551 frame->tf_rax = td->td_retval[0]; 552 frame->tf_rdx = td->td_retval[1]; 553 frame->tf_rflags &= ~PSL_C; 554 return; 555 } 556 557 switch (error) { 558 case ERESTART: 559 /* 560 * Reconstruct pc, we know that 'syscall' is 2 bytes, 561 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 562 * We saved this in tf_err. 563 * %r10 (which was holding the value of %rcx) is restored 564 * for the next iteration. 565 * %r10 restore is only required for freebsd/amd64 processes, 566 * but shall be innocent for any ia32 ABI. 567 * 568 * Require full context restore to get the arguments 569 * in the registers reloaded at return to usermode. 570 */ 571 frame->tf_rip -= frame->tf_err; 572 frame->tf_r10 = frame->tf_rcx; 573 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 574 break; 575 576 case EJUSTRETURN: 577 break; 578 579 default: 580 frame->tf_rax = error; 581 frame->tf_rflags |= PSL_C; 582 break; 583 } 584 } 585 586 /* 587 * Initialize machine state, mostly pcb and trap frame for a new 588 * thread, about to return to userspace. Put enough state in the new 589 * thread's PCB to get it to go back to the fork_return(), which 590 * finalizes the thread state and handles peculiarities of the first 591 * return to userspace for the new thread. 592 */ 593 void 594 cpu_copy_thread(struct thread *td, struct thread *td0) 595 { 596 copy_thread(td0, td); 597 598 /* 599 * Copy user general-purpose registers. 600 * 601 * Some of these registers are rewritten by cpu_set_upcall() 602 * and linux_set_upcall(). 603 */ 604 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 605 606 /* If the current thread has the trap bit set (i.e. a debugger had 607 * single stepped the process to the system call), we need to clear 608 * the trap flag from the new frame. Otherwise, the new thread will 609 * receive a (likely unexpected) SIGTRAP when it executes the first 610 * instruction after returning to userland. 611 */ 612 td->td_frame->tf_rflags &= ~PSL_T; 613 614 set_pcb_flags_raw(td->td_pcb, PCB_FULL_IRET); 615 } 616 617 /* 618 * Set that machine state for performing an upcall that starts 619 * the entry function with the given argument. 620 */ 621 void 622 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 623 stack_t *stack) 624 { 625 626 /* 627 * Do any extra cleaning that needs to be done. 628 * The thread may have optional components 629 * that are not present in a fresh thread. 630 * This may be a recycled thread so make it look 631 * as though it's newly allocated. 632 */ 633 cpu_thread_clean(td); 634 635 #ifdef COMPAT_FREEBSD32 636 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 637 /* 638 * Set the trap frame to point at the beginning of the entry 639 * function. 640 */ 641 td->td_frame->tf_rbp = 0; 642 td->td_frame->tf_rsp = 643 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 644 td->td_frame->tf_rip = (uintptr_t)entry; 645 646 /* Return address sentinel value to stop stack unwinding. */ 647 suword32((void *)td->td_frame->tf_rsp, 0); 648 649 /* Pass the argument to the entry point. */ 650 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 651 (uint32_t)(uintptr_t)arg); 652 653 return; 654 } 655 #endif 656 657 /* 658 * Set the trap frame to point at the beginning of the uts 659 * function. 660 */ 661 td->td_frame->tf_rbp = 0; 662 td->td_frame->tf_rsp = 663 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; 664 td->td_frame->tf_rsp -= 8; 665 td->td_frame->tf_rip = (register_t)entry; 666 td->td_frame->tf_ds = _udatasel; 667 td->td_frame->tf_es = _udatasel; 668 td->td_frame->tf_fs = _ufssel; 669 td->td_frame->tf_gs = _ugssel; 670 td->td_frame->tf_flags = TF_HASSEGS; 671 672 /* Return address sentinel value to stop stack unwinding. */ 673 suword((void *)td->td_frame->tf_rsp, 0); 674 675 /* Pass the argument to the entry point. */ 676 td->td_frame->tf_rdi = (register_t)arg; 677 } 678 679 int 680 cpu_set_user_tls(struct thread *td, void *tls_base) 681 { 682 struct pcb *pcb; 683 684 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 685 return (EINVAL); 686 687 pcb = td->td_pcb; 688 set_pcb_flags(pcb, PCB_FULL_IRET); 689 #ifdef COMPAT_FREEBSD32 690 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 691 pcb->pcb_gsbase = (register_t)tls_base; 692 return (0); 693 } 694 #endif 695 pcb->pcb_fsbase = (register_t)tls_base; 696 return (0); 697 } 698 699 /* 700 * Software interrupt handler for queued VM system processing. 701 */ 702 void 703 swi_vm(void *dummy) 704 { 705 if (busdma_swi_pending != 0) 706 busdma_swi(); 707 } 708 709 /* 710 * Tell whether this address is in some physical memory region. 711 * Currently used by the kernel coredump code in order to avoid 712 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 713 * or other unpredictable behaviour. 714 */ 715 716 int 717 is_physical_memory(vm_paddr_t addr) 718 { 719 720 #ifdef DEV_ISA 721 /* The ISA ``memory hole''. */ 722 if (addr >= 0xa0000 && addr < 0x100000) 723 return 0; 724 #endif 725 726 /* 727 * stuff other tests for known memory-mapped devices (PCI?) 728 * here 729 */ 730 731 return 1; 732 } 733