1 /*- 2 * Copyright (c) 2014 Andrew Turner 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/exec.h> 34 #include <sys/imgact.h> 35 #include <sys/kdb.h> 36 #include <sys/kernel.h> 37 #include <sys/ktr.h> 38 #include <sys/limits.h> 39 #include <sys/lock.h> 40 #include <sys/mutex.h> 41 #include <sys/proc.h> 42 #include <sys/ptrace.h> 43 #include <sys/reg.h> 44 #include <sys/rwlock.h> 45 #include <sys/signalvar.h> 46 #include <sys/syscallsubr.h> 47 #include <sys/sysent.h> 48 #include <sys/sysproto.h> 49 #include <sys/ucontext.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_param.h> 53 #include <vm/pmap.h> 54 #include <vm/vm_map.h> 55 56 #include <machine/armreg.h> 57 #include <machine/kdb.h> 58 #include <machine/md_var.h> 59 #include <machine/pcb.h> 60 61 #ifdef VFP 62 #include <machine/vfp.h> 63 #endif 64 65 _Static_assert(sizeof(mcontext_t) == 880, "mcontext_t size incorrect"); 66 _Static_assert(sizeof(ucontext_t) == 960, "ucontext_t size incorrect"); 67 _Static_assert(sizeof(siginfo_t) == 80, "siginfo_t size incorrect"); 68 69 static void get_fpcontext(struct thread *td, mcontext_t *mcp); 70 static void set_fpcontext(struct thread *td, mcontext_t *mcp); 71 72 int 73 fill_regs(struct thread *td, struct reg *regs) 74 { 75 struct trapframe *frame; 76 77 frame = td->td_frame; 78 regs->sp = frame->tf_sp; 79 regs->lr = frame->tf_lr; 80 regs->elr = frame->tf_elr; 81 regs->spsr = frame->tf_spsr; 82 83 memcpy(regs->x, frame->tf_x, sizeof(regs->x)); 84 85 #ifdef COMPAT_FREEBSD32 86 /* 87 * We may be called here for a 32bits process, if we're using a 88 * 64bits debugger. If so, put PC and SPSR where it expects it. 89 */ 90 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 91 regs->x[15] = frame->tf_elr; 92 regs->x[16] = frame->tf_spsr; 93 } 94 #endif 95 return (0); 96 } 97 98 int 99 set_regs(struct thread *td, struct reg *regs) 100 { 101 struct trapframe *frame; 102 103 frame = td->td_frame; 104 frame->tf_sp = regs->sp; 105 frame->tf_lr = regs->lr; 106 107 memcpy(frame->tf_x, regs->x, sizeof(frame->tf_x)); 108 109 #ifdef COMPAT_FREEBSD32 110 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 111 /* 112 * We may be called for a 32bits process if we're using 113 * a 64bits debugger. If so, get PC and SPSR from where 114 * it put it. 115 */ 116 frame->tf_elr = regs->x[15]; 117 frame->tf_spsr &= ~PSR_SETTABLE_32; 118 frame->tf_spsr |= regs->x[16] & PSR_SETTABLE_32; 119 /* Don't allow userspace to ask to continue single stepping. 120 * The SPSR.SS field doesn't exist when the EL1 is AArch32. 121 * As the SPSR.DIT field has moved in its place don't 122 * allow userspace to set the SPSR.SS field. 123 */ 124 } else 125 #endif 126 { 127 frame->tf_elr = regs->elr; 128 frame->tf_spsr &= ~PSR_SETTABLE_64; 129 frame->tf_spsr |= regs->spsr & PSR_SETTABLE_64; 130 /* Enable single stepping if userspace asked fot it */ 131 if ((frame->tf_spsr & PSR_SS) != 0) { 132 td->td_pcb->pcb_flags |= PCB_SINGLE_STEP; 133 134 WRITE_SPECIALREG(mdscr_el1, 135 READ_SPECIALREG(mdscr_el1) | MDSCR_SS); 136 isb(); 137 } 138 } 139 return (0); 140 } 141 142 int 143 fill_fpregs(struct thread *td, struct fpreg *regs) 144 { 145 #ifdef VFP 146 struct pcb *pcb; 147 148 pcb = td->td_pcb; 149 if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 150 /* 151 * If we have just been running VFP instructions we will 152 * need to save the state to memcpy it below. 153 */ 154 if (td == curthread) 155 vfp_save_state(td, pcb); 156 157 KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate, 158 ("Called fill_fpregs while the kernel is using the VFP")); 159 memcpy(regs->fp_q, pcb->pcb_fpustate.vfp_regs, 160 sizeof(regs->fp_q)); 161 regs->fp_cr = pcb->pcb_fpustate.vfp_fpcr; 162 regs->fp_sr = pcb->pcb_fpustate.vfp_fpsr; 163 } else 164 #endif 165 memset(regs, 0, sizeof(*regs)); 166 return (0); 167 } 168 169 int 170 set_fpregs(struct thread *td, struct fpreg *regs) 171 { 172 #ifdef VFP 173 struct pcb *pcb; 174 175 pcb = td->td_pcb; 176 KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate, 177 ("Called set_fpregs while the kernel is using the VFP")); 178 memcpy(pcb->pcb_fpustate.vfp_regs, regs->fp_q, sizeof(regs->fp_q)); 179 pcb->pcb_fpustate.vfp_fpcr = regs->fp_cr; 180 pcb->pcb_fpustate.vfp_fpsr = regs->fp_sr; 181 #endif 182 return (0); 183 } 184 185 int 186 fill_dbregs(struct thread *td, struct dbreg *regs) 187 { 188 struct debug_monitor_state *monitor; 189 int i; 190 uint8_t debug_ver, nbkpts, nwtpts; 191 192 memset(regs, 0, sizeof(*regs)); 193 194 extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_DebugVer_SHIFT, 195 &debug_ver); 196 extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_BRPs_SHIFT, 197 &nbkpts); 198 extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_WRPs_SHIFT, 199 &nwtpts); 200 201 /* 202 * The BRPs field contains the number of breakpoints - 1. Armv8-A 203 * allows the hardware to provide 2-16 breakpoints so this won't 204 * overflow an 8 bit value. The same applies to the WRPs field. 205 */ 206 nbkpts++; 207 nwtpts++; 208 209 regs->db_debug_ver = debug_ver; 210 regs->db_nbkpts = nbkpts; 211 regs->db_nwtpts = nwtpts; 212 213 monitor = &td->td_pcb->pcb_dbg_regs; 214 if ((monitor->dbg_flags & DBGMON_ENABLED) != 0) { 215 for (i = 0; i < nbkpts; i++) { 216 regs->db_breakregs[i].dbr_addr = monitor->dbg_bvr[i]; 217 regs->db_breakregs[i].dbr_ctrl = monitor->dbg_bcr[i]; 218 } 219 for (i = 0; i < nwtpts; i++) { 220 regs->db_watchregs[i].dbw_addr = monitor->dbg_wvr[i]; 221 regs->db_watchregs[i].dbw_ctrl = monitor->dbg_wcr[i]; 222 } 223 } 224 225 return (0); 226 } 227 228 int 229 set_dbregs(struct thread *td, struct dbreg *regs) 230 { 231 struct debug_monitor_state *monitor; 232 uint64_t addr; 233 uint32_t ctrl; 234 int i; 235 236 monitor = &td->td_pcb->pcb_dbg_regs; 237 monitor->dbg_enable_count = 0; 238 239 for (i = 0; i < DBG_BRP_MAX; i++) { 240 addr = regs->db_breakregs[i].dbr_addr; 241 ctrl = regs->db_breakregs[i].dbr_ctrl; 242 243 /* 244 * Don't let the user set a breakpoint on a kernel or 245 * non-canonical user address. 246 */ 247 if (addr >= VM_MAXUSER_ADDRESS) 248 return (EINVAL); 249 250 /* 251 * The lowest 2 bits are ignored, so record the effective 252 * address. 253 */ 254 addr = rounddown2(addr, 4); 255 256 /* 257 * Some control fields are ignored, and other bits reserved. 258 * Only unlinked, address-matching breakpoints are supported. 259 * 260 * XXX: fields that appear unvalidated, such as BAS, have 261 * constrained undefined behaviour. If the user mis-programs 262 * these, there is no risk to the system. 263 */ 264 ctrl &= DBGBCR_EN | DBGBCR_PMC | DBGBCR_BAS; 265 if ((ctrl & DBGBCR_EN) != 0) { 266 /* Only target EL0. */ 267 if ((ctrl & DBGBCR_PMC) != DBGBCR_PMC_EL0) 268 return (EINVAL); 269 270 monitor->dbg_enable_count++; 271 } 272 273 monitor->dbg_bvr[i] = addr; 274 monitor->dbg_bcr[i] = ctrl; 275 } 276 277 for (i = 0; i < DBG_WRP_MAX; i++) { 278 addr = regs->db_watchregs[i].dbw_addr; 279 ctrl = regs->db_watchregs[i].dbw_ctrl; 280 281 /* 282 * Don't let the user set a watchpoint on a kernel or 283 * non-canonical user address. 284 */ 285 if (addr >= VM_MAXUSER_ADDRESS) 286 return (EINVAL); 287 288 /* 289 * Some control fields are ignored, and other bits reserved. 290 * Only unlinked watchpoints are supported. 291 */ 292 ctrl &= DBGWCR_EN | DBGWCR_PAC | DBGWCR_LSC | DBGWCR_BAS | 293 DBGWCR_MASK; 294 295 if ((ctrl & DBGWCR_EN) != 0) { 296 /* Only target EL0. */ 297 if ((ctrl & DBGWCR_PAC) != DBGWCR_PAC_EL0) 298 return (EINVAL); 299 300 /* Must set at least one of the load/store bits. */ 301 if ((ctrl & DBGWCR_LSC) == 0) 302 return (EINVAL); 303 304 /* 305 * When specifying the address range with BAS, the MASK 306 * field must be zero. 307 */ 308 if ((ctrl & DBGWCR_BAS) != DBGWCR_BAS && 309 (ctrl & DBGWCR_MASK) != 0) 310 return (EINVAL); 311 312 monitor->dbg_enable_count++; 313 } 314 monitor->dbg_wvr[i] = addr; 315 monitor->dbg_wcr[i] = ctrl; 316 } 317 318 if (monitor->dbg_enable_count > 0) 319 monitor->dbg_flags |= DBGMON_ENABLED; 320 321 return (0); 322 } 323 324 #ifdef COMPAT_FREEBSD32 325 int 326 fill_regs32(struct thread *td, struct reg32 *regs) 327 { 328 int i; 329 struct trapframe *tf; 330 331 tf = td->td_frame; 332 for (i = 0; i < 13; i++) 333 regs->r[i] = tf->tf_x[i]; 334 /* For arm32, SP is r13 and LR is r14 */ 335 regs->r_sp = tf->tf_x[13]; 336 regs->r_lr = tf->tf_x[14]; 337 regs->r_pc = tf->tf_elr; 338 regs->r_cpsr = tf->tf_spsr; 339 340 return (0); 341 } 342 343 int 344 set_regs32(struct thread *td, struct reg32 *regs) 345 { 346 int i; 347 struct trapframe *tf; 348 349 tf = td->td_frame; 350 for (i = 0; i < 13; i++) 351 tf->tf_x[i] = regs->r[i]; 352 /* For arm 32, SP is r13 an LR is r14 */ 353 tf->tf_x[13] = regs->r_sp; 354 tf->tf_x[14] = regs->r_lr; 355 tf->tf_elr = regs->r_pc; 356 tf->tf_spsr &= ~PSR_SETTABLE_32; 357 tf->tf_spsr |= regs->r_cpsr & PSR_SETTABLE_32; 358 359 return (0); 360 } 361 362 /* XXX fill/set dbregs/fpregs are stubbed on 32-bit arm. */ 363 int 364 fill_fpregs32(struct thread *td, struct fpreg32 *regs) 365 { 366 367 memset(regs, 0, sizeof(*regs)); 368 return (0); 369 } 370 371 int 372 set_fpregs32(struct thread *td, struct fpreg32 *regs) 373 { 374 375 return (0); 376 } 377 378 int 379 fill_dbregs32(struct thread *td, struct dbreg32 *regs) 380 { 381 382 memset(regs, 0, sizeof(*regs)); 383 return (0); 384 } 385 386 int 387 set_dbregs32(struct thread *td, struct dbreg32 *regs) 388 { 389 390 return (0); 391 } 392 #endif 393 394 void 395 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack) 396 { 397 struct trapframe *tf = td->td_frame; 398 struct pcb *pcb = td->td_pcb; 399 400 memset(tf, 0, sizeof(struct trapframe)); 401 402 tf->tf_x[0] = stack; 403 tf->tf_sp = STACKALIGN(stack); 404 tf->tf_lr = imgp->entry_addr; 405 tf->tf_elr = imgp->entry_addr; 406 407 td->td_pcb->pcb_tpidr_el0 = 0; 408 td->td_pcb->pcb_tpidrro_el0 = 0; 409 WRITE_SPECIALREG(tpidrro_el0, 0); 410 WRITE_SPECIALREG(tpidr_el0, 0); 411 412 #ifdef VFP 413 vfp_reset_state(td, pcb); 414 #endif 415 416 /* 417 * Clear debug register state. It is not applicable to the new process. 418 */ 419 bzero(&pcb->pcb_dbg_regs, sizeof(pcb->pcb_dbg_regs)); 420 421 /* Generate new pointer authentication keys */ 422 ptrauth_exec(td); 423 } 424 425 /* Sanity check these are the same size, they will be memcpy'd to and from */ 426 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) == 427 sizeof((struct gpregs *)0)->gp_x); 428 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) == 429 sizeof((struct reg *)0)->x); 430 431 int 432 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret) 433 { 434 struct trapframe *tf = td->td_frame; 435 436 if (clear_ret & GET_MC_CLEAR_RET) { 437 mcp->mc_gpregs.gp_x[0] = 0; 438 mcp->mc_gpregs.gp_spsr = tf->tf_spsr & ~PSR_C; 439 } else { 440 mcp->mc_gpregs.gp_x[0] = tf->tf_x[0]; 441 mcp->mc_gpregs.gp_spsr = tf->tf_spsr; 442 } 443 444 memcpy(&mcp->mc_gpregs.gp_x[1], &tf->tf_x[1], 445 sizeof(mcp->mc_gpregs.gp_x[1]) * (nitems(mcp->mc_gpregs.gp_x) - 1)); 446 447 mcp->mc_gpregs.gp_sp = tf->tf_sp; 448 mcp->mc_gpregs.gp_lr = tf->tf_lr; 449 mcp->mc_gpregs.gp_elr = tf->tf_elr; 450 get_fpcontext(td, mcp); 451 452 return (0); 453 } 454 455 int 456 set_mcontext(struct thread *td, mcontext_t *mcp) 457 { 458 struct trapframe *tf = td->td_frame; 459 uint32_t spsr; 460 461 spsr = mcp->mc_gpregs.gp_spsr; 462 if ((spsr & PSR_M_MASK) != PSR_M_EL0t || 463 (spsr & PSR_AARCH32) != 0 || 464 (spsr & PSR_DAIF) != (td->td_frame->tf_spsr & PSR_DAIF)) 465 return (EINVAL); 466 467 memcpy(tf->tf_x, mcp->mc_gpregs.gp_x, sizeof(tf->tf_x)); 468 469 tf->tf_sp = mcp->mc_gpregs.gp_sp; 470 tf->tf_lr = mcp->mc_gpregs.gp_lr; 471 tf->tf_elr = mcp->mc_gpregs.gp_elr; 472 tf->tf_spsr = mcp->mc_gpregs.gp_spsr; 473 if ((tf->tf_spsr & PSR_SS) != 0) { 474 td->td_pcb->pcb_flags |= PCB_SINGLE_STEP; 475 476 WRITE_SPECIALREG(mdscr_el1, 477 READ_SPECIALREG(mdscr_el1) | MDSCR_SS); 478 isb(); 479 } 480 set_fpcontext(td, mcp); 481 482 return (0); 483 } 484 485 static void 486 get_fpcontext(struct thread *td, mcontext_t *mcp) 487 { 488 #ifdef VFP 489 struct pcb *curpcb; 490 491 critical_enter(); 492 493 curpcb = curthread->td_pcb; 494 495 if ((curpcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 496 /* 497 * If we have just been running VFP instructions we will 498 * need to save the state to memcpy it below. 499 */ 500 vfp_save_state(td, curpcb); 501 502 KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate, 503 ("Called get_fpcontext while the kernel is using the VFP")); 504 KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0, 505 ("Non-userspace FPU flags set in get_fpcontext")); 506 memcpy(mcp->mc_fpregs.fp_q, curpcb->pcb_fpustate.vfp_regs, 507 sizeof(mcp->mc_fpregs.fp_q)); 508 mcp->mc_fpregs.fp_cr = curpcb->pcb_fpustate.vfp_fpcr; 509 mcp->mc_fpregs.fp_sr = curpcb->pcb_fpustate.vfp_fpsr; 510 mcp->mc_fpregs.fp_flags = curpcb->pcb_fpflags; 511 mcp->mc_flags |= _MC_FP_VALID; 512 } 513 514 critical_exit(); 515 #endif 516 } 517 518 static void 519 set_fpcontext(struct thread *td, mcontext_t *mcp) 520 { 521 #ifdef VFP 522 struct pcb *curpcb; 523 524 critical_enter(); 525 526 if ((mcp->mc_flags & _MC_FP_VALID) != 0) { 527 curpcb = curthread->td_pcb; 528 529 /* 530 * Discard any vfp state for the current thread, we 531 * are about to override it. 532 */ 533 vfp_discard(td); 534 535 KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate, 536 ("Called set_fpcontext while the kernel is using the VFP")); 537 memcpy(curpcb->pcb_fpustate.vfp_regs, mcp->mc_fpregs.fp_q, 538 sizeof(mcp->mc_fpregs.fp_q)); 539 curpcb->pcb_fpustate.vfp_fpcr = mcp->mc_fpregs.fp_cr; 540 curpcb->pcb_fpustate.vfp_fpsr = mcp->mc_fpregs.fp_sr; 541 curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK; 542 } 543 544 critical_exit(); 545 #endif 546 } 547 548 int 549 sys_sigreturn(struct thread *td, struct sigreturn_args *uap) 550 { 551 ucontext_t uc; 552 int error; 553 554 if (copyin(uap->sigcntxp, &uc, sizeof(uc))) 555 return (EFAULT); 556 557 error = set_mcontext(td, &uc.uc_mcontext); 558 if (error != 0) 559 return (error); 560 561 /* Restore signal mask. */ 562 kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0); 563 564 return (EJUSTRETURN); 565 } 566 567 void 568 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 569 { 570 struct thread *td; 571 struct proc *p; 572 struct trapframe *tf; 573 struct sigframe *fp, frame; 574 struct sigacts *psp; 575 int onstack, sig; 576 577 td = curthread; 578 p = td->td_proc; 579 PROC_LOCK_ASSERT(p, MA_OWNED); 580 581 sig = ksi->ksi_signo; 582 psp = p->p_sigacts; 583 mtx_assert(&psp->ps_mtx, MA_OWNED); 584 585 tf = td->td_frame; 586 onstack = sigonstack(tf->tf_sp); 587 588 CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm, 589 catcher, sig); 590 591 /* Allocate and validate space for the signal handler context. */ 592 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack && 593 SIGISMEMBER(psp->ps_sigonstack, sig)) { 594 fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 595 td->td_sigstk.ss_size); 596 #if defined(COMPAT_43) 597 td->td_sigstk.ss_flags |= SS_ONSTACK; 598 #endif 599 } else { 600 fp = (struct sigframe *)td->td_frame->tf_sp; 601 } 602 603 /* Make room, keeping the stack aligned */ 604 fp--; 605 fp = (struct sigframe *)STACKALIGN(fp); 606 607 /* Fill in the frame to copy out */ 608 bzero(&frame, sizeof(frame)); 609 get_mcontext(td, &frame.sf_uc.uc_mcontext, 0); 610 frame.sf_si = ksi->ksi_info; 611 frame.sf_uc.uc_sigmask = *mask; 612 frame.sf_uc.uc_stack = td->td_sigstk; 613 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ? 614 (onstack ? SS_ONSTACK : 0) : SS_DISABLE; 615 mtx_unlock(&psp->ps_mtx); 616 PROC_UNLOCK(td->td_proc); 617 618 /* Copy the sigframe out to the user's stack. */ 619 if (copyout(&frame, fp, sizeof(*fp)) != 0) { 620 /* Process has trashed its stack. Kill it. */ 621 CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp); 622 PROC_LOCK(p); 623 sigexit(td, SIGILL); 624 } 625 626 tf->tf_x[0] = sig; 627 tf->tf_x[1] = (register_t)&fp->sf_si; 628 tf->tf_x[2] = (register_t)&fp->sf_uc; 629 tf->tf_x[8] = (register_t)catcher; 630 tf->tf_sp = (register_t)fp; 631 tf->tf_elr = (register_t)PROC_SIGCODE(p); 632 633 /* Clear the single step flag while in the signal handler */ 634 if ((td->td_pcb->pcb_flags & PCB_SINGLE_STEP) != 0) { 635 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP; 636 WRITE_SPECIALREG(mdscr_el1, 637 READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS); 638 isb(); 639 } 640 641 CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_elr, 642 tf->tf_sp); 643 644 PROC_LOCK(p); 645 mtx_lock(&psp->ps_mtx); 646 } 647