sys/arm64/arm64/exec_machdep.c

   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
 158         KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
 159             ("Called fill_fpregs while the kernel is using the VFP"));
 160         memcpy(regs->fp_q, pcb->pcb_fpustate.vfp_regs,
 161             sizeof(regs->fp_q));
 162         regs->fp_cr = pcb->pcb_fpustate.vfp_fpcr;
 163         regs->fp_sr = pcb->pcb_fpustate.vfp_fpsr;
 164 #else
 165         memset(regs, 0, sizeof(*regs));
 166 #endif
 167         return (0);
 168 }
 169
 170 int
 171 set_fpregs(struct thread *td, struct fpreg *regs)
 172 {
 173 #ifdef VFP
 174         struct pcb *pcb;
 175
 176         pcb = td->td_pcb;
 177         KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
 178             ("Called set_fpregs while the kernel is using the VFP"));
 179         memcpy(pcb->pcb_fpustate.vfp_regs, regs->fp_q, sizeof(regs->fp_q));
 180         pcb->pcb_fpustate.vfp_fpcr = regs->fp_cr;
 181         pcb->pcb_fpustate.vfp_fpsr = regs->fp_sr;
 182 #endif
 183         return (0);
 184 }
 185
 186 int
 187 fill_dbregs(struct thread *td, struct dbreg *regs)
 188 {
 189         struct debug_monitor_state *monitor;
 190         int i;
 191         uint8_t debug_ver, nbkpts, nwtpts;
 192
 193         memset(regs, 0, sizeof(*regs));
 194
 195         extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_DebugVer_SHIFT,
 196             &debug_ver);
 197         extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_BRPs_SHIFT,
 198             &nbkpts);
 199         extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_WRPs_SHIFT,
 200             &nwtpts);
 201
 202         /*
 203          * The BRPs field contains the number of breakpoints - 1. Armv8-A
 204          * allows the hardware to provide 2-16 breakpoints so this won't
 205          * overflow an 8 bit value. The same applies to the WRPs field.
 206          */
 207         nbkpts++;
 208         nwtpts++;
 209
 210         regs->db_debug_ver = debug_ver;
 211         regs->db_nbkpts = nbkpts;
 212         regs->db_nwtpts = nwtpts;
 213
 214         monitor = &td->td_pcb->pcb_dbg_regs;
 215         if ((monitor->dbg_flags & DBGMON_ENABLED) != 0) {
 216                 for (i = 0; i < nbkpts; i++) {
 217                         regs->db_breakregs[i].dbr_addr = monitor->dbg_bvr[i];
 218                         regs->db_breakregs[i].dbr_ctrl = monitor->dbg_bcr[i];
 219                 }
 220                 for (i = 0; i < nwtpts; i++) {
 221                         regs->db_watchregs[i].dbw_addr = monitor->dbg_wvr[i];
 222                         regs->db_watchregs[i].dbw_ctrl = monitor->dbg_wcr[i];
 223                 }
 224         }
 225
 226         return (0);
 227 }
 228
 229 int
 230 set_dbregs(struct thread *td, struct dbreg *regs)
 231 {
 232         struct debug_monitor_state *monitor;
 233         uint64_t addr;
 234         uint32_t ctrl;
 235         int i;
 236
 237         monitor = &td->td_pcb->pcb_dbg_regs;
 238         monitor->dbg_enable_count = 0;
 239
 240         for (i = 0; i < DBG_BRP_MAX; i++) {
 241                 addr = regs->db_breakregs[i].dbr_addr;
 242                 ctrl = regs->db_breakregs[i].dbr_ctrl;
 243
 244                 /*
 245                  * Don't let the user set a breakpoint on a kernel or
 246                  * non-canonical user address.
 247                  */
 248                 if (addr >= VM_MAXUSER_ADDRESS)
 249                         return (EINVAL);
 250
 251                 /*
 252                  * The lowest 2 bits are ignored, so record the effective
 253                  * address.
 254                  */
 255                 addr = rounddown2(addr, 4);
 256
 257                 /*
 258                  * Some control fields are ignored, and other bits reserved.
 259                  * Only unlinked, address-matching breakpoints are supported.
 260                  *
 261                  * XXX: fields that appear unvalidated, such as BAS, have
 262                  * constrained undefined behaviour. If the user mis-programs
 263                  * these, there is no risk to the system.
 264                  */
 265                 ctrl &= DBGBCR_EN | DBGBCR_PMC | DBGBCR_BAS;
 266                 if ((ctrl & DBGBCR_EN) != 0) {
 267                         /* Only target EL0. */
 268                         if ((ctrl & DBGBCR_PMC) != DBGBCR_PMC_EL0)
 269                                 return (EINVAL);
 270
 271                         monitor->dbg_enable_count++;
 272                 }
 273
 274                 monitor->dbg_bvr[i] = addr;
 275                 monitor->dbg_bcr[i] = ctrl;
 276         }
 277
 278         for (i = 0; i < DBG_WRP_MAX; i++) {
 279                 addr = regs->db_watchregs[i].dbw_addr;
 280                 ctrl = regs->db_watchregs[i].dbw_ctrl;
 281
 282                 /*
 283                  * Don't let the user set a watchpoint on a kernel or
 284                  * non-canonical user address.
 285                  */
 286                 if (addr >= VM_MAXUSER_ADDRESS)
 287                         return (EINVAL);
 288
 289                 /*
 290                  * Some control fields are ignored, and other bits reserved.
 291                  * Only unlinked watchpoints are supported.
 292                  */
 293                 ctrl &= DBGWCR_EN | DBGWCR_PAC | DBGWCR_LSC | DBGWCR_BAS |
 294                     DBGWCR_MASK;
 295
 296                 if ((ctrl & DBGWCR_EN) != 0) {
 297                         /* Only target EL0. */
 298                         if ((ctrl & DBGWCR_PAC) != DBGWCR_PAC_EL0)
 299                                 return (EINVAL);
 300
 301                         /* Must set at least one of the load/store bits. */
 302                         if ((ctrl & DBGWCR_LSC) == 0)
 303                                 return (EINVAL);
 304
 305                         /*
 306                          * When specifying the address range with BAS, the MASK
 307                          * field must be zero.
 308                          */
 309                         if ((ctrl & DBGWCR_BAS) != DBGWCR_BAS &&
 310                             (ctrl & DBGWCR_MASK) != 0)
 311                                 return (EINVAL);
 312
 313                         monitor->dbg_enable_count++;
 314                 }
 315                 monitor->dbg_wvr[i] = addr;
 316                 monitor->dbg_wcr[i] = ctrl;
 317         }
 318
 319         if (monitor->dbg_enable_count > 0)
 320                 monitor->dbg_flags |= DBGMON_ENABLED;
 321
 322         return (0);
 323 }
 324
 325 #ifdef COMPAT_FREEBSD32
 326 int
 327 fill_regs32(struct thread *td, struct reg32 *regs)
 328 {
 329         int i;
 330         struct trapframe *tf;
 331
 332         tf = td->td_frame;
 333         for (i = 0; i < 13; i++)
 334                 regs->r[i] = tf->tf_x[i];
 335         /* For arm32, SP is r13 and LR is r14 */
 336         regs->r_sp = tf->tf_x[13];
 337         regs->r_lr = tf->tf_x[14];
 338         regs->r_pc = tf->tf_elr;
 339         regs->r_cpsr = tf->tf_spsr;
 340
 341         return (0);
 342 }
 343
 344 int
 345 set_regs32(struct thread *td, struct reg32 *regs)
 346 {
 347         int i;
 348         struct trapframe *tf;
 349
 350         tf = td->td_frame;
 351         for (i = 0; i < 13; i++)
 352                 tf->tf_x[i] = regs->r[i];
 353         /* For arm 32, SP is r13 an LR is r14 */
 354         tf->tf_x[13] = regs->r_sp;
 355         tf->tf_x[14] = regs->r_lr;
 356         tf->tf_elr = regs->r_pc;
 357         tf->tf_spsr &= ~PSR_SETTABLE_32;
 358         tf->tf_spsr |= regs->r_cpsr & PSR_SETTABLE_32;
 359
 360         return (0);
 361 }
 362
 363 /* XXX fill/set dbregs/fpregs are stubbed on 32-bit arm. */
 364 int
 365 fill_fpregs32(struct thread *td, struct fpreg32 *regs)
 366 {
 367
 368         memset(regs, 0, sizeof(*regs));
 369         return (0);
 370 }
 371
 372 int
 373 set_fpregs32(struct thread *td, struct fpreg32 *regs)
 374 {
 375
 376         return (0);
 377 }
 378
 379 int
 380 fill_dbregs32(struct thread *td, struct dbreg32 *regs)
 381 {
 382
 383         memset(regs, 0, sizeof(*regs));
 384         return (0);
 385 }
 386
 387 int
 388 set_dbregs32(struct thread *td, struct dbreg32 *regs)
 389 {
 390
 391         return (0);
 392 }
 393 #endif
 394
 395 void
 396 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
 397 {
 398         struct trapframe *tf = td->td_frame;
 399         struct pcb *pcb = td->td_pcb;
 400
 401         memset(tf, 0, sizeof(struct trapframe));
 402
 403         tf->tf_x[0] = stack;
 404         tf->tf_sp = STACKALIGN(stack);
 405         tf->tf_lr = imgp->entry_addr;
 406         tf->tf_elr = imgp->entry_addr;
 407
 408         td->td_pcb->pcb_tpidr_el0 = 0;
 409         td->td_pcb->pcb_tpidrro_el0 = 0;
 410         WRITE_SPECIALREG(tpidrro_el0, 0);
 411         WRITE_SPECIALREG(tpidr_el0, 0);
 412
 413 #ifdef VFP
 414         vfp_reset_state(td, pcb);
 415 #endif
 416
 417         /*
 418          * Clear debug register state. It is not applicable to the new process.
 419          */
 420         bzero(&pcb->pcb_dbg_regs, sizeof(pcb->pcb_dbg_regs));
 421
 422         /* Generate new pointer authentication keys */
 423         ptrauth_exec(td);
 424 }
 425
 426 /* Sanity check these are the same size, they will be memcpy'd to and from */
 427 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) ==
 428     sizeof((struct gpregs *)0)->gp_x);
 429 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) ==
 430     sizeof((struct reg *)0)->x);
 431
 432 int
 433 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret)
 434 {
 435         struct trapframe *tf = td->td_frame;
 436
 437         if (clear_ret & GET_MC_CLEAR_RET) {
 438                 mcp->mc_gpregs.gp_x[0] = 0;
 439                 mcp->mc_gpregs.gp_spsr = tf->tf_spsr & ~PSR_C;
 440         } else {
 441                 mcp->mc_gpregs.gp_x[0] = tf->tf_x[0];
 442                 mcp->mc_gpregs.gp_spsr = tf->tf_spsr;
 443         }
 444
 445         memcpy(&mcp->mc_gpregs.gp_x[1], &tf->tf_x[1],
 446             sizeof(mcp->mc_gpregs.gp_x[1]) * (nitems(mcp->mc_gpregs.gp_x) - 1));
 447
 448         mcp->mc_gpregs.gp_sp = tf->tf_sp;
 449         mcp->mc_gpregs.gp_lr = tf->tf_lr;
 450         mcp->mc_gpregs.gp_elr = tf->tf_elr;
 451         get_fpcontext(td, mcp);
 452
 453         return (0);
 454 }
 455
 456 int
 457 set_mcontext(struct thread *td, mcontext_t *mcp)
 458 {
 459         struct trapframe *tf = td->td_frame;
 460         uint32_t spsr;
 461
 462         spsr = mcp->mc_gpregs.gp_spsr;
 463         if ((spsr & PSR_M_MASK) != PSR_M_EL0t ||
 464             (spsr & PSR_AARCH32) != 0 ||
 465             (spsr & PSR_DAIF) != (td->td_frame->tf_spsr & PSR_DAIF))
 466                 return (EINVAL);
 467
 468         memcpy(tf->tf_x, mcp->mc_gpregs.gp_x, sizeof(tf->tf_x));
 469
 470         tf->tf_sp = mcp->mc_gpregs.gp_sp;
 471         tf->tf_lr = mcp->mc_gpregs.gp_lr;
 472         tf->tf_elr = mcp->mc_gpregs.gp_elr;
 473         tf->tf_spsr = mcp->mc_gpregs.gp_spsr;
 474         if ((tf->tf_spsr & PSR_SS) != 0) {
 475                 td->td_pcb->pcb_flags |= PCB_SINGLE_STEP;
 476
 477                 WRITE_SPECIALREG(mdscr_el1,
 478                     READ_SPECIALREG(mdscr_el1) | MDSCR_SS);
 479                 isb();
 480         }
 481         set_fpcontext(td, mcp);
 482
 483         return (0);
 484 }
 485
 486 static void
 487 get_fpcontext(struct thread *td, mcontext_t *mcp)
 488 {
 489 #ifdef VFP
 490         struct pcb *curpcb;
 491
 492         MPASS(td == curthread);
 493
 494         curpcb = curthread->td_pcb;
 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
 503         KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate,
 504             ("Called get_fpcontext while the kernel is using the VFP"));
 505         KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
 506             ("Non-userspace FPU flags set in get_fpcontext"));
 507         memcpy(mcp->mc_fpregs.fp_q, curpcb->pcb_fpustate.vfp_regs,
 508             sizeof(mcp->mc_fpregs.fp_q));
 509         mcp->mc_fpregs.fp_cr = curpcb->pcb_fpustate.vfp_fpcr;
 510         mcp->mc_fpregs.fp_sr = curpcb->pcb_fpustate.vfp_fpsr;
 511         mcp->mc_fpregs.fp_flags = curpcb->pcb_fpflags;
 512         mcp->mc_flags |= _MC_FP_VALID;
 513 #endif
 514 }
 515
 516 static void
 517 set_fpcontext(struct thread *td, mcontext_t *mcp)
 518 {
 519 #ifdef VFP
 520         struct pcb *curpcb;
 521
 522         MPASS(td == curthread);
 523         if ((mcp->mc_flags & _MC_FP_VALID) != 0) {
 524                 curpcb = curthread->td_pcb;
 525
 526                 /*
 527                  * Discard any vfp state for the current thread, we
 528                  * are about to override it.
 529                  */
 530                 critical_enter();
 531                 vfp_discard(td);
 532                 critical_exit();
 533
 534                 KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate,
 535                     ("Called set_fpcontext while the kernel is using the VFP"));
 536                 memcpy(curpcb->pcb_fpustate.vfp_regs, mcp->mc_fpregs.fp_q,
 537                     sizeof(mcp->mc_fpregs.fp_q));
 538                 curpcb->pcb_fpustate.vfp_fpcr = mcp->mc_fpregs.fp_cr;
 539                 curpcb->pcb_fpustate.vfp_fpsr = mcp->mc_fpregs.fp_sr;
 540                 curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK;
 541         }
 542 #endif
 543 }
 544
 545 int
 546 sys_sigreturn(struct thread *td, struct sigreturn_args *uap)
 547 {
 548         ucontext_t uc;
 549         int error;
 550
 551         if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
 552                 return (EFAULT);
 553
 554         error = set_mcontext(td, &uc.uc_mcontext);
 555         if (error != 0)
 556                 return (error);
 557
 558         /* Restore signal mask. */
 559         kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
 560
 561         return (EJUSTRETURN);
 562 }
 563
 564 void
 565 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 566 {
 567         struct thread *td;
 568         struct proc *p;
 569         struct trapframe *tf;
 570         struct sigframe *fp, frame;
 571         struct sigacts *psp;
 572         int onstack, sig;
 573
 574         td = curthread;
 575         p = td->td_proc;
 576         PROC_LOCK_ASSERT(p, MA_OWNED);
 577
 578         sig = ksi->ksi_signo;
 579         psp = p->p_sigacts;
 580         mtx_assert(&psp->ps_mtx, MA_OWNED);
 581
 582         tf = td->td_frame;
 583         onstack = sigonstack(tf->tf_sp);
 584
 585         CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
 586             catcher, sig);
 587
 588         /* Allocate and validate space for the signal handler context. */
 589         if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack &&
 590             SIGISMEMBER(psp->ps_sigonstack, sig)) {
 591                 fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
 592                     td->td_sigstk.ss_size);
 593 #if defined(COMPAT_43)
 594                 td->td_sigstk.ss_flags |= SS_ONSTACK;
 595 #endif
 596         } else {
 597                 fp = (struct sigframe *)td->td_frame->tf_sp;
 598         }
 599
 600         /* Make room, keeping the stack aligned */
 601         fp--;
 602         fp = (struct sigframe *)STACKALIGN(fp);
 603
 604         /* Fill in the frame to copy out */
 605         bzero(&frame, sizeof(frame));
 606         get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);
 607         frame.sf_si = ksi->ksi_info;
 608         frame.sf_uc.uc_sigmask = *mask;
 609         frame.sf_uc.uc_stack = td->td_sigstk;
 610         frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
 611             (onstack ? SS_ONSTACK : 0) : SS_DISABLE;
 612         mtx_unlock(&psp->ps_mtx);
 613         PROC_UNLOCK(td->td_proc);
 614
 615         /* Copy the sigframe out to the user's stack. */
 616         if (copyout(&frame, fp, sizeof(*fp)) != 0) {
 617                 /* Process has trashed its stack. Kill it. */
 618                 CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
 619                 PROC_LOCK(p);
 620                 sigexit(td, SIGILL);
 621         }
 622
 623         tf->tf_x[0] = sig;
 624         tf->tf_x[1] = (register_t)&fp->sf_si;
 625         tf->tf_x[2] = (register_t)&fp->sf_uc;
 626         tf->tf_x[8] = (register_t)catcher;
 627         tf->tf_sp = (register_t)fp;
 628         tf->tf_elr = (register_t)PROC_SIGCODE(p);
 629
 630         /* Clear the single step flag while in the signal handler */
 631         if ((td->td_pcb->pcb_flags & PCB_SINGLE_STEP) != 0) {
 632                 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP;
 633                 WRITE_SPECIALREG(mdscr_el1,
 634                     READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS);
 635                 isb();
 636         }
 637
 638         CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_elr,
 639             tf->tf_sp);
 640
 641         PROC_LOCK(p);
 642         mtx_lock(&psp->ps_mtx);
 643 }