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                 /*
 129                  * frame->tf_spsr and regs->spsr on FreeBSD 13 was 32-bit
 130                  * where from 14 they are 64 bit. As PSR_SETTABLE_64 clears
 131                  * the upper 32 bits no compatibility handling is needed,
 132                  * however if this is ever not the case we will need to add
 133                  * these, similar to how it is done in set_mcontext.
 134                  */
 135                 frame->tf_spsr &= ~PSR_SETTABLE_64;
 136                 frame->tf_spsr |= regs->spsr & PSR_SETTABLE_64;
 137                 /* Enable single stepping if userspace asked fot it */
 138                 if ((frame->tf_spsr & PSR_SS) != 0) {
 139                         td->td_pcb->pcb_flags |= PCB_SINGLE_STEP;
 140
 141                         WRITE_SPECIALREG(mdscr_el1,
 142                             READ_SPECIALREG(mdscr_el1) | MDSCR_SS);
 143                         isb();
 144                 }
 145         }
 146         return (0);
 147 }
 148
 149 int
 150 fill_fpregs(struct thread *td, struct fpreg *regs)
 151 {
 152 #ifdef VFP
 153         struct pcb *pcb;
 154
 155         pcb = td->td_pcb;
 156         if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
 157                 /*
 158                  * If we have just been running VFP instructions we will
 159                  * need to save the state to memcpy it below.
 160                  */
 161                 if (td == curthread)
 162                         vfp_save_state(td, pcb);
 163         }
 164
 165         KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
 166             ("Called fill_fpregs while the kernel is using the VFP"));
 167         memcpy(regs->fp_q, pcb->pcb_fpustate.vfp_regs,
 168             sizeof(regs->fp_q));
 169         regs->fp_cr = pcb->pcb_fpustate.vfp_fpcr;
 170         regs->fp_sr = pcb->pcb_fpustate.vfp_fpsr;
 171 #else
 172         memset(regs, 0, sizeof(*regs));
 173 #endif
 174         return (0);
 175 }
 176
 177 int
 178 set_fpregs(struct thread *td, struct fpreg *regs)
 179 {
 180 #ifdef VFP
 181         struct pcb *pcb;
 182
 183         pcb = td->td_pcb;
 184         KASSERT(pcb->pcb_fpusaved == &pcb->pcb_fpustate,
 185             ("Called set_fpregs while the kernel is using the VFP"));
 186         memcpy(pcb->pcb_fpustate.vfp_regs, regs->fp_q, sizeof(regs->fp_q));
 187         pcb->pcb_fpustate.vfp_fpcr = regs->fp_cr;
 188         pcb->pcb_fpustate.vfp_fpsr = regs->fp_sr;
 189 #endif
 190         return (0);
 191 }
 192
 193 int
 194 fill_dbregs(struct thread *td, struct dbreg *regs)
 195 {
 196         struct debug_monitor_state *monitor;
 197         int i;
 198         uint8_t debug_ver, nbkpts, nwtpts;
 199
 200         memset(regs, 0, sizeof(*regs));
 201
 202         extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_DebugVer_SHIFT,
 203             &debug_ver);
 204         extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_BRPs_SHIFT,
 205             &nbkpts);
 206         extract_user_id_field(ID_AA64DFR0_EL1, ID_AA64DFR0_WRPs_SHIFT,
 207             &nwtpts);
 208
 209         /*
 210          * The BRPs field contains the number of breakpoints - 1. Armv8-A
 211          * allows the hardware to provide 2-16 breakpoints so this won't
 212          * overflow an 8 bit value. The same applies to the WRPs field.
 213          */
 214         nbkpts++;
 215         nwtpts++;
 216
 217         regs->db_debug_ver = debug_ver;
 218         regs->db_nbkpts = nbkpts;
 219         regs->db_nwtpts = nwtpts;
 220
 221         monitor = &td->td_pcb->pcb_dbg_regs;
 222         if ((monitor->dbg_flags & DBGMON_ENABLED) != 0) {
 223                 for (i = 0; i < nbkpts; i++) {
 224                         regs->db_breakregs[i].dbr_addr = monitor->dbg_bvr[i];
 225                         regs->db_breakregs[i].dbr_ctrl = monitor->dbg_bcr[i];
 226                 }
 227                 for (i = 0; i < nwtpts; i++) {
 228                         regs->db_watchregs[i].dbw_addr = monitor->dbg_wvr[i];
 229                         regs->db_watchregs[i].dbw_ctrl = monitor->dbg_wcr[i];
 230                 }
 231         }
 232
 233         return (0);
 234 }
 235
 236 int
 237 set_dbregs(struct thread *td, struct dbreg *regs)
 238 {
 239         struct debug_monitor_state *monitor;
 240         uint64_t addr;
 241         uint32_t ctrl;
 242         int i;
 243
 244         monitor = &td->td_pcb->pcb_dbg_regs;
 245         monitor->dbg_enable_count = 0;
 246
 247         for (i = 0; i < DBG_BRP_MAX; i++) {
 248                 addr = regs->db_breakregs[i].dbr_addr;
 249                 ctrl = regs->db_breakregs[i].dbr_ctrl;
 250
 251                 /*
 252                  * Don't let the user set a breakpoint on a kernel or
 253                  * non-canonical user address.
 254                  */
 255                 if (addr >= VM_MAXUSER_ADDRESS)
 256                         return (EINVAL);
 257
 258                 /*
 259                  * The lowest 2 bits are ignored, so record the effective
 260                  * address.
 261                  */
 262                 addr = rounddown2(addr, 4);
 263
 264                 /*
 265                  * Some control fields are ignored, and other bits reserved.
 266                  * Only unlinked, address-matching breakpoints are supported.
 267                  *
 268                  * XXX: fields that appear unvalidated, such as BAS, have
 269                  * constrained undefined behaviour. If the user mis-programs
 270                  * these, there is no risk to the system.
 271                  */
 272                 ctrl &= DBGBCR_EN | DBGBCR_PMC | DBGBCR_BAS;
 273                 if ((ctrl & DBGBCR_EN) != 0) {
 274                         /* Only target EL0. */
 275                         if ((ctrl & DBGBCR_PMC) != DBGBCR_PMC_EL0)
 276                                 return (EINVAL);
 277
 278                         monitor->dbg_enable_count++;
 279                 }
 280
 281                 monitor->dbg_bvr[i] = addr;
 282                 monitor->dbg_bcr[i] = ctrl;
 283         }
 284
 285         for (i = 0; i < DBG_WRP_MAX; i++) {
 286                 addr = regs->db_watchregs[i].dbw_addr;
 287                 ctrl = regs->db_watchregs[i].dbw_ctrl;
 288
 289                 /*
 290                  * Don't let the user set a watchpoint on a kernel or
 291                  * non-canonical user address.
 292                  */
 293                 if (addr >= VM_MAXUSER_ADDRESS)
 294                         return (EINVAL);
 295
 296                 /*
 297                  * Some control fields are ignored, and other bits reserved.
 298                  * Only unlinked watchpoints are supported.
 299                  */
 300                 ctrl &= DBGWCR_EN | DBGWCR_PAC | DBGWCR_LSC | DBGWCR_BAS |
 301                     DBGWCR_MASK;
 302
 303                 if ((ctrl & DBGWCR_EN) != 0) {
 304                         /* Only target EL0. */
 305                         if ((ctrl & DBGWCR_PAC) != DBGWCR_PAC_EL0)
 306                                 return (EINVAL);
 307
 308                         /* Must set at least one of the load/store bits. */
 309                         if ((ctrl & DBGWCR_LSC) == 0)
 310                                 return (EINVAL);
 311
 312                         /*
 313                          * When specifying the address range with BAS, the MASK
 314                          * field must be zero.
 315                          */
 316                         if ((ctrl & DBGWCR_BAS) != DBGWCR_BAS &&
 317                             (ctrl & DBGWCR_MASK) != 0)
 318                                 return (EINVAL);
 319
 320                         monitor->dbg_enable_count++;
 321                 }
 322                 monitor->dbg_wvr[i] = addr;
 323                 monitor->dbg_wcr[i] = ctrl;
 324         }
 325
 326         if (monitor->dbg_enable_count > 0)
 327                 monitor->dbg_flags |= DBGMON_ENABLED;
 328
 329         return (0);
 330 }
 331
 332 #ifdef COMPAT_FREEBSD32
 333 int
 334 fill_regs32(struct thread *td, struct reg32 *regs)
 335 {
 336         int i;
 337         struct trapframe *tf;
 338
 339         tf = td->td_frame;
 340         for (i = 0; i < 13; i++)
 341                 regs->r[i] = tf->tf_x[i];
 342         /* For arm32, SP is r13 and LR is r14 */
 343         regs->r_sp = tf->tf_x[13];
 344         regs->r_lr = tf->tf_x[14];
 345         regs->r_pc = tf->tf_elr;
 346         regs->r_cpsr = tf->tf_spsr;
 347
 348         return (0);
 349 }
 350
 351 int
 352 set_regs32(struct thread *td, struct reg32 *regs)
 353 {
 354         int i;
 355         struct trapframe *tf;
 356
 357         tf = td->td_frame;
 358         for (i = 0; i < 13; i++)
 359                 tf->tf_x[i] = regs->r[i];
 360         /* For arm 32, SP is r13 an LR is r14 */
 361         tf->tf_x[13] = regs->r_sp;
 362         tf->tf_x[14] = regs->r_lr;
 363         tf->tf_elr = regs->r_pc;
 364         tf->tf_spsr &= ~PSR_SETTABLE_32;
 365         tf->tf_spsr |= regs->r_cpsr & PSR_SETTABLE_32;
 366
 367         return (0);
 368 }
 369
 370 /* XXX fill/set dbregs/fpregs are stubbed on 32-bit arm. */
 371 int
 372 fill_fpregs32(struct thread *td, struct fpreg32 *regs)
 373 {
 374
 375         memset(regs, 0, sizeof(*regs));
 376         return (0);
 377 }
 378
 379 int
 380 set_fpregs32(struct thread *td, struct fpreg32 *regs)
 381 {
 382
 383         return (0);
 384 }
 385
 386 int
 387 fill_dbregs32(struct thread *td, struct dbreg32 *regs)
 388 {
 389
 390         memset(regs, 0, sizeof(*regs));
 391         return (0);
 392 }
 393
 394 int
 395 set_dbregs32(struct thread *td, struct dbreg32 *regs)
 396 {
 397
 398         return (0);
 399 }
 400 #endif
 401
 402 void
 403 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack)
 404 {
 405         struct trapframe *tf = td->td_frame;
 406         struct pcb *pcb = td->td_pcb;
 407
 408         memset(tf, 0, sizeof(struct trapframe));
 409
 410         tf->tf_x[0] = stack;
 411         tf->tf_sp = STACKALIGN(stack);
 412         tf->tf_lr = imgp->entry_addr;
 413         tf->tf_elr = imgp->entry_addr;
 414
 415         td->td_pcb->pcb_tpidr_el0 = 0;
 416         td->td_pcb->pcb_tpidrro_el0 = 0;
 417         WRITE_SPECIALREG(tpidrro_el0, 0);
 418         WRITE_SPECIALREG(tpidr_el0, 0);
 419
 420 #ifdef VFP
 421         vfp_reset_state(td, pcb);
 422 #endif
 423
 424         /*
 425          * Clear debug register state. It is not applicable to the new process.
 426          */
 427         bzero(&pcb->pcb_dbg_regs, sizeof(pcb->pcb_dbg_regs));
 428
 429         /* Generate new pointer authentication keys */
 430         ptrauth_exec(td);
 431 }
 432
 433 /* Sanity check these are the same size, they will be memcpy'd to and from */
 434 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) ==
 435     sizeof((struct gpregs *)0)->gp_x);
 436 CTASSERT(sizeof(((struct trapframe *)0)->tf_x) ==
 437     sizeof((struct reg *)0)->x);
 438
 439 int
 440 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret)
 441 {
 442         struct trapframe *tf = td->td_frame;
 443
 444         if (clear_ret & GET_MC_CLEAR_RET) {
 445                 mcp->mc_gpregs.gp_x[0] = 0;
 446                 mcp->mc_gpregs.gp_spsr = tf->tf_spsr & ~PSR_C;
 447         } else {
 448                 mcp->mc_gpregs.gp_x[0] = tf->tf_x[0];
 449                 mcp->mc_gpregs.gp_spsr = tf->tf_spsr;
 450         }
 451
 452         memcpy(&mcp->mc_gpregs.gp_x[1], &tf->tf_x[1],
 453             sizeof(mcp->mc_gpregs.gp_x[1]) * (nitems(mcp->mc_gpregs.gp_x) - 1));
 454
 455         mcp->mc_gpregs.gp_sp = tf->tf_sp;
 456         mcp->mc_gpregs.gp_lr = tf->tf_lr;
 457         mcp->mc_gpregs.gp_elr = tf->tf_elr;
 458         get_fpcontext(td, mcp);
 459
 460         return (0);
 461 }
 462
 463 int
 464 set_mcontext(struct thread *td, mcontext_t *mcp)
 465 {
 466 #define PSR_13_MASK     0xfffffffful
 467         struct trapframe *tf = td->td_frame;
 468         uint64_t spsr;
 469
 470         spsr = mcp->mc_gpregs.gp_spsr;
 471 #ifdef COMPAT_FREEBSD13
 472         if (td->td_proc->p_osrel < P_OSREL_ARM64_SPSR) {
 473                 /*
 474                  * Before FreeBSD 14 gp_spsr was 32 bit. The size of mc_gpregs
 475                  * was identical because of padding so mask of the upper bits
 476                  * that may be invalid on earlier releases.
 477                  */
 478                 spsr &= PSR_13_MASK;
 479         }
 480 #endif
 481
 482         if ((spsr & PSR_M_MASK) != PSR_M_EL0t ||
 483             (spsr & PSR_AARCH32) != 0 ||
 484             (spsr & PSR_DAIF) != (td->td_frame->tf_spsr & PSR_DAIF))
 485                 return (EINVAL);
 486
 487         memcpy(tf->tf_x, mcp->mc_gpregs.gp_x, sizeof(tf->tf_x));
 488
 489         tf->tf_sp = mcp->mc_gpregs.gp_sp;
 490         tf->tf_lr = mcp->mc_gpregs.gp_lr;
 491         tf->tf_elr = mcp->mc_gpregs.gp_elr;
 492 #ifdef COMPAT_FREEBSD13
 493         if (td->td_proc->p_osrel < P_OSREL_ARM64_SPSR) {
 494                 /* Keep the upper 32 bits of spsr on older releases */
 495                 tf->tf_spsr &= ~PSR_13_MASK;
 496                 tf->tf_spsr |= spsr;
 497         } else
 498 #endif
 499                 tf->tf_spsr = spsr;
 500         if ((tf->tf_spsr & PSR_SS) != 0) {
 501                 td->td_pcb->pcb_flags |= PCB_SINGLE_STEP;
 502
 503                 WRITE_SPECIALREG(mdscr_el1,
 504                     READ_SPECIALREG(mdscr_el1) | MDSCR_SS);
 505                 isb();
 506         }
 507         set_fpcontext(td, mcp);
 508
 509         return (0);
 510 #undef PSR_13_MASK
 511 }
 512
 513 static void
 514 get_fpcontext(struct thread *td, mcontext_t *mcp)
 515 {
 516 #ifdef VFP
 517         struct pcb *curpcb;
 518
 519         MPASS(td == curthread);
 520
 521         curpcb = curthread->td_pcb;
 522         if ((curpcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
 523                 /*
 524                  * If we have just been running VFP instructions we will
 525                  * need to save the state to memcpy it below.
 526                  */
 527                 vfp_save_state(td, curpcb);
 528         }
 529
 530         KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate,
 531             ("Called get_fpcontext while the kernel is using the VFP"));
 532         KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0,
 533             ("Non-userspace FPU flags set in get_fpcontext"));
 534         memcpy(mcp->mc_fpregs.fp_q, curpcb->pcb_fpustate.vfp_regs,
 535             sizeof(mcp->mc_fpregs.fp_q));
 536         mcp->mc_fpregs.fp_cr = curpcb->pcb_fpustate.vfp_fpcr;
 537         mcp->mc_fpregs.fp_sr = curpcb->pcb_fpustate.vfp_fpsr;
 538         mcp->mc_fpregs.fp_flags = curpcb->pcb_fpflags;
 539         mcp->mc_flags |= _MC_FP_VALID;
 540 #endif
 541 }
 542
 543 static void
 544 set_fpcontext(struct thread *td, mcontext_t *mcp)
 545 {
 546 #ifdef VFP
 547         struct pcb *curpcb;
 548
 549         MPASS(td == curthread);
 550         if ((mcp->mc_flags & _MC_FP_VALID) != 0) {
 551                 curpcb = curthread->td_pcb;
 552
 553                 /*
 554                  * Discard any vfp state for the current thread, we
 555                  * are about to override it.
 556                  */
 557                 critical_enter();
 558                 vfp_discard(td);
 559                 critical_exit();
 560
 561                 KASSERT(curpcb->pcb_fpusaved == &curpcb->pcb_fpustate,
 562                     ("Called set_fpcontext while the kernel is using the VFP"));
 563                 memcpy(curpcb->pcb_fpustate.vfp_regs, mcp->mc_fpregs.fp_q,
 564                     sizeof(mcp->mc_fpregs.fp_q));
 565                 curpcb->pcb_fpustate.vfp_fpcr = mcp->mc_fpregs.fp_cr;
 566                 curpcb->pcb_fpustate.vfp_fpsr = mcp->mc_fpregs.fp_sr;
 567                 curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK;
 568         }
 569 #endif
 570 }
 571
 572 int
 573 sys_sigreturn(struct thread *td, struct sigreturn_args *uap)
 574 {
 575         ucontext_t uc;
 576         int error;
 577
 578         if (copyin(uap->sigcntxp, &uc, sizeof(uc)))
 579                 return (EFAULT);
 580
 581         error = set_mcontext(td, &uc.uc_mcontext);
 582         if (error != 0)
 583                 return (error);
 584
 585         /* Restore signal mask. */
 586         kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
 587
 588         return (EJUSTRETURN);
 589 }
 590
 591 void
 592 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 593 {
 594         struct thread *td;
 595         struct proc *p;
 596         struct trapframe *tf;
 597         struct sigframe *fp, frame;
 598         struct sigacts *psp;
 599         int onstack, sig;
 600
 601         td = curthread;
 602         p = td->td_proc;
 603         PROC_LOCK_ASSERT(p, MA_OWNED);
 604
 605         sig = ksi->ksi_signo;
 606         psp = p->p_sigacts;
 607         mtx_assert(&psp->ps_mtx, MA_OWNED);
 608
 609         tf = td->td_frame;
 610         onstack = sigonstack(tf->tf_sp);
 611
 612         CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm,
 613             catcher, sig);
 614
 615         /* Allocate and validate space for the signal handler context. */
 616         if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack &&
 617             SIGISMEMBER(psp->ps_sigonstack, sig)) {
 618                 fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
 619                     td->td_sigstk.ss_size);
 620 #if defined(COMPAT_43)
 621                 td->td_sigstk.ss_flags |= SS_ONSTACK;
 622 #endif
 623         } else {
 624                 fp = (struct sigframe *)td->td_frame->tf_sp;
 625         }
 626
 627         /* Make room, keeping the stack aligned */
 628         fp--;
 629         fp = (struct sigframe *)STACKALIGN(fp);
 630
 631         /* Fill in the frame to copy out */
 632         bzero(&frame, sizeof(frame));
 633         get_mcontext(td, &frame.sf_uc.uc_mcontext, 0);
 634         frame.sf_si = ksi->ksi_info;
 635         frame.sf_uc.uc_sigmask = *mask;
 636         frame.sf_uc.uc_stack = td->td_sigstk;
 637         frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
 638             (onstack ? SS_ONSTACK : 0) : SS_DISABLE;
 639         mtx_unlock(&psp->ps_mtx);
 640         PROC_UNLOCK(td->td_proc);
 641
 642         /* Copy the sigframe out to the user's stack. */
 643         if (copyout(&frame, fp, sizeof(*fp)) != 0) {
 644                 /* Process has trashed its stack. Kill it. */
 645                 CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp);
 646                 PROC_LOCK(p);
 647                 sigexit(td, SIGILL);
 648         }
 649
 650         tf->tf_x[0] = sig;
 651         tf->tf_x[1] = (register_t)&fp->sf_si;
 652         tf->tf_x[2] = (register_t)&fp->sf_uc;
 653         tf->tf_x[8] = (register_t)catcher;
 654         tf->tf_sp = (register_t)fp;
 655         tf->tf_elr = (register_t)PROC_SIGCODE(p);
 656
 657         /* Clear the single step flag while in the signal handler */
 658         if ((td->td_pcb->pcb_flags & PCB_SINGLE_STEP) != 0) {
 659                 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP;
 660                 WRITE_SPECIALREG(mdscr_el1,
 661                     READ_SPECIALREG(mdscr_el1) & ~MDSCR_SS);
 662                 isb();
 663         }
 664
 665         CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_elr,
 666             tf->tf_sp);
 667
 668         PROC_LOCK(p);
 669         mtx_lock(&psp->ps_mtx);
 670 }