1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25 
  26 #include <sys/param.h>
  27 #include <sys/vmparam.h>
  28 #include <sys/types.h>
  29 #include <sys/sysmacros.h>
  30 #include <sys/systm.h>
  31 #include <sys/signal.h>
  32 #include <sys/stack.h>
  33 #include <sys/cred.h>
  34 #include <sys/cmn_err.h>
  35 #include <sys/user.h>
  36 #include <sys/privregs.h>
  37 #include <sys/psw.h>
  38 #include <sys/debug.h>
  39 #include <sys/errno.h>
  40 #include <sys/proc.h>
  41 #include <sys/modctl.h>
  42 #include <sys/var.h>
  43 #include <sys/inline.h>
  44 #include <sys/syscall.h>
  45 #include <sys/ucontext.h>
  46 #include <sys/cpuvar.h>
  47 #include <sys/siginfo.h>
  48 #include <sys/trap.h>
  49 #include <sys/vtrace.h>
  50 #include <sys/sysinfo.h>
  51 #include <sys/procfs.h>
  52 #include <sys/prsystm.h>
  53 #include <c2/audit.h>
  54 #include <sys/modctl.h>
  55 #include <sys/aio_impl.h>
  56 #include <sys/tnf.h>
  57 #include <sys/tnf_probe.h>
  58 #include <sys/copyops.h>
  59 #include <sys/priv.h>
  60 #include <sys/msacct.h>
  61 
  62 int syscalltrace = 0;
  63 #ifdef SYSCALLTRACE
  64 static kmutex_t systrace_lock;          /* syscall tracing lock */
  65 #else
  66 #define syscalltrace 0
  67 #endif /* SYSCALLTRACE */
  68 
  69 typedef int64_t (*llfcn_t)();   /* function returning long long */
  70 
  71 int pre_syscall(void);
  72 void post_syscall(long rval1, long rval2);
  73 static krwlock_t *lock_syscall(struct sysent *, uint_t);
  74 void deferred_singlestep_trap(caddr_t);
  75 
  76 #ifdef _SYSCALL32_IMPL
  77 #define LWP_GETSYSENT(lwp)      \
  78         (lwp_getdatamodel(lwp) == DATAMODEL_NATIVE ? sysent : sysent32)
  79 #else
  80 #define LWP_GETSYSENT(lwp)      (sysent)
  81 #endif
  82 
  83 /*
  84  * If watchpoints are active, don't make copying in of
  85  * system call arguments take a read watchpoint trap.
  86  */
  87 static int
  88 copyin_args(struct regs *rp, long *ap, uint_t nargs)
  89 {
  90         greg_t *sp = 1 + (greg_t *)rp->r_sp;         /* skip ret addr */
  91 
  92         ASSERT(nargs <= MAXSYSARGS);
  93 
  94         return (copyin_nowatch(sp, ap, nargs * sizeof (*sp)));
  95 }
  96 
  97 #if defined(_SYSCALL32_IMPL)
  98 static int
  99 copyin_args32(struct regs *rp, long *ap, uint_t nargs)
 100 {
 101         greg32_t *sp = 1 + (greg32_t *)rp->r_sp;     /* skip ret addr */
 102         uint32_t a32[MAXSYSARGS];
 103         int rc;
 104 
 105         ASSERT(nargs <= MAXSYSARGS);
 106 
 107         if ((rc = copyin_nowatch(sp, a32, nargs * sizeof (*sp))) == 0) {
 108                 uint32_t *a32p = &a32[0];
 109 
 110                 while (nargs--)
 111                         *ap++ = (ulong_t)*a32p++;
 112         }
 113         return (rc);
 114 }
 115 #define COPYIN_ARGS32   copyin_args32
 116 #else
 117 #define COPYIN_ARGS32   copyin_args
 118 #endif
 119 
 120 /*
 121  * Error handler for system calls where arg copy gets fault.
 122  */
 123 static longlong_t
 124 syscall_err()
 125 {
 126         return (0);
 127 }
 128 
 129 /*
 130  * Corresponding sysent entry to allow syscall_entry caller
 131  * to invoke syscall_err.
 132  */
 133 static struct sysent sysent_err =  {
 134         0, SE_32RVAL1, NULL, NULL, (llfcn_t)syscall_err
 135 };
 136 
 137 /*
 138  * Called from syscall() when a non-trivial 32-bit system call occurs.
 139  *      Sets up the args and returns a pointer to the handler.
 140  */
 141 struct sysent *
 142 syscall_entry(kthread_t *t, long *argp)
 143 {
 144         klwp_t *lwp = ttolwp(t);
 145         struct regs *rp = lwptoregs(lwp);
 146         unsigned int code;
 147         struct sysent *callp;
 148         struct sysent *se = LWP_GETSYSENT(lwp);
 149         int error = 0;
 150         uint_t nargs;
 151 
 152         ASSERT(t == curthread);
 153 
 154         lwp->lwp_ru.sysc++;
 155         lwp->lwp_eosys = NORMALRETURN;       /* assume this will be normal */
 156 
 157         /*
 158          * Set lwp_ap to point to the args, even if none are needed for this
 159          * system call.  This is for the loadable-syscall case where the
 160          * number of args won't be known until the system call is loaded, and
 161          * also maintains a non-NULL lwp_ap setup for get_syscall_args(). Note
 162          * that lwp_ap MUST be set to a non-NULL value _BEFORE_ t_sysnum is
 163          * set to non-zero; otherwise get_syscall_args(), seeing a non-zero
 164          * t_sysnum for this thread, will charge ahead and dereference lwp_ap.
 165          */
 166         lwp->lwp_ap = argp;          /* for get_syscall_args */
 167 
 168         code = rp->r_r0;
 169         t->t_sysnum = (short)code;
 170         callp = code >= NSYSCALL ? &nosys_ent : se + code;
 171 
 172         if ((t->t_pre_sys | syscalltrace) != 0) {
 173                 error = pre_syscall();
 174 
 175                 /*
 176                  * pre_syscall() has taken care so that lwp_ap is current;
 177                  * it either points to syscall-entry-saved amd64 regs,
 178                  * or it points to lwp_arg[], which has been re-copied from
 179                  * the ia32 ustack, but either way, it's a current copy after
 180                  * /proc has possibly mucked with the syscall args.
 181                  */
 182 
 183                 if (error)
 184                         return (&sysent_err);       /* use dummy handler */
 185         }
 186 
 187         /*
 188          * Fetch the system call arguments to the kernel stack copy used
 189          * for syscall handling.
 190          * Note: for loadable system calls the number of arguments required
 191          * may not be known at this point, and will be zero if the system call
 192          * was never loaded.  Once the system call has been loaded, the number
 193          * of args is not allowed to be changed.
 194          */
 195         if ((nargs = (uint_t)callp->sy_narg) != 0 &&
 196             COPYIN_ARGS32(rp, argp, nargs)) {
 197                 (void) set_errno(EFAULT);
 198                 return (&sysent_err);       /* use dummy handler */
 199         }
 200 
 201         return (callp);         /* return sysent entry for caller */
 202 }
 203 
 204 void
 205 syscall_exit(kthread_t *t, long rval1, long rval2)
 206 {
 207         /*
 208          * Handle signals and other post-call events if necessary.
 209          */
 210         if ((t->t_post_sys_ast | syscalltrace) == 0) {
 211                 klwp_t *lwp = ttolwp(t);
 212                 struct regs *rp = lwptoregs(lwp);
 213 
 214                 /*
 215                  * Normal return.
 216                  * Clear error indication and set return values.
 217                  */
 218                 rp->r_ps &= ~PS_C;       /* reset carry bit */
 219                 rp->r_r0 = rval1;
 220                 rp->r_r1 = rval2;
 221                 lwp->lwp_state = LWP_USER;
 222         } else
 223                 post_syscall(rval1, rval2);
 224         t->t_sysnum = 0;             /* invalidate args */
 225 }
 226 
 227 /*
 228  * Perform pre-system-call processing, including stopping for tracing,
 229  * auditing, etc.
 230  *
 231  * This routine is called only if the t_pre_sys flag is set. Any condition
 232  * requiring pre-syscall handling must set the t_pre_sys flag. If the
 233  * condition is persistent, this routine will repost t_pre_sys.
 234  */
 235 int
 236 pre_syscall()
 237 {
 238         kthread_t *t = curthread;
 239         unsigned code = t->t_sysnum;
 240         klwp_t *lwp = ttolwp(t);
 241         proc_t *p = ttoproc(t);
 242         int     repost;
 243 
 244         t->t_pre_sys = repost = 0;   /* clear pre-syscall processing flag */
 245 
 246 #if defined(DEBUG)
 247         /*
 248          * On the i386 kernel, lwp_ap points at the piece of the thread
 249          * stack that we copy the users arguments into.
 250          *
 251          * On the amd64 kernel, the syscall arguments in the rdi..r9
 252          * registers should be pointed at by lwp_ap.  If the args need to
 253          * be copied so that those registers can be changed without losing
 254          * the ability to get the args for /proc, they can be saved by
 255          * save_syscall_args(), and lwp_ap will be restored by post_syscall().
 256          */
 257         if (lwp_getdatamodel(lwp) == DATAMODEL_NATIVE) {
 258 #if defined(_LP64)
 259                 ASSERT(lwp->lwp_ap == (long *)&lwptoregs(lwp)->r_rdi);
 260         } else {
 261 #endif
 262                 ASSERT((caddr_t)lwp->lwp_ap > t->t_stkbase &&
 263                     (caddr_t)lwp->lwp_ap < t->t_stk);
 264         }
 265 #endif  /* DEBUG */
 266 
 267         /*
 268          * Make sure the thread is holding the latest credentials for the
 269          * process.  The credentials in the process right now apply to this
 270          * thread for the entire system call.
 271          */
 272         if (t->t_cred != p->p_cred) {
 273                 cred_t *oldcred = t->t_cred;
 274                 /*
 275                  * DTrace accesses t_cred in probe context.  t_cred must
 276                  * always be either NULL, or point to a valid, allocated cred
 277                  * structure.
 278                  */
 279                 t->t_cred = crgetcred();
 280                 crfree(oldcred);
 281         }
 282 
 283         /*
 284          * From the proc(4) manual page:
 285          * When entry to a system call is being traced, the traced process
 286          * stops after having begun the call to the system but before the
 287          * system call arguments have been fetched from the process.
 288          */
 289         if (PTOU(p)->u_systrap) {
 290                 if (prismember(&PTOU(p)->u_entrymask, code)) {
 291                         mutex_enter(&p->p_lock);
 292                         /*
 293                          * Recheck stop condition, now that lock is held.
 294                          */
 295                         if (PTOU(p)->u_systrap &&
 296                             prismember(&PTOU(p)->u_entrymask, code)) {
 297                                 stop(PR_SYSENTRY, code);
 298 
 299                                 /*
 300                                  * /proc may have modified syscall args,
 301                                  * either in regs for amd64 or on ustack
 302                                  * for ia32.  Either way, arrange to
 303                                  * copy them again, both for the syscall
 304                                  * handler and for other consumers in
 305                                  * post_syscall (like audit).  Here, we
 306                                  * only do amd64, and just set lwp_ap
 307                                  * back to the kernel-entry stack copy;
 308                                  * the syscall ml code redoes
 309                                  * move-from-regs to set up for the
 310                                  * syscall handler after we return.  For
 311                                  * ia32, save_syscall_args() below makes
 312                                  * an lwp_ap-accessible copy.
 313                                  */
 314 #if defined(_LP64)
 315                                 if (lwp_getdatamodel(lwp) == DATAMODEL_NATIVE) {
 316                                         lwp->lwp_argsaved = 0;
 317                                         lwp->lwp_ap =
 318                                             (long *)&lwptoregs(lwp)->r_rdi;
 319                                 }
 320 #endif
 321                         }
 322                         mutex_exit(&p->p_lock);
 323                 }
 324                 repost = 1;
 325         }
 326 
 327         /*
 328          * ia32 kernel, or ia32 proc on amd64 kernel: keep args in
 329          * lwp_arg for post-syscall processing, regardless of whether
 330          * they might have been changed in /proc above.
 331          */
 332 #if defined(_LP64)
 333         if (lwp_getdatamodel(lwp) != DATAMODEL_NATIVE)
 334 #endif
 335                 (void) save_syscall_args();
 336 
 337         if (lwp->lwp_sysabort) {
 338                 /*
 339                  * lwp_sysabort may have been set via /proc while the process
 340                  * was stopped on PR_SYSENTRY.  If so, abort the system call.
 341                  * Override any error from the copyin() of the arguments.
 342                  */
 343                 lwp->lwp_sysabort = 0;
 344                 (void) set_errno(EINTR);        /* forces post_sys */
 345                 t->t_pre_sys = 1;    /* repost anyway */
 346                 return (1);             /* don't do system call, return EINTR */
 347         }
 348 
 349         /*
 350          * begin auditing for this syscall if the c2audit module is loaded
 351          * and auditing is enabled
 352          */
 353         if (audit_active == C2AUDIT_LOADED) {
 354                 uint32_t auditing = au_zone_getstate(NULL);
 355 
 356                 if (auditing & AU_AUDIT_MASK) {
 357                         int error;
 358                         if (error = audit_start(T_SYSCALL, code, auditing, \
 359                             0, lwp)) {
 360                                 t->t_pre_sys = 1;    /* repost anyway */
 361                                 (void) set_errno(error);
 362                                 return (1);
 363                         }
 364                         repost = 1;
 365                 }
 366         }
 367 
 368 #ifndef NPROBE
 369         /* Kernel probe */
 370         if (tnf_tracing_active) {
 371                 TNF_PROBE_1(syscall_start, "syscall thread", /* CSTYLED */,
 372                         tnf_sysnum,     sysnum,         t->t_sysnum);
 373                 t->t_post_sys = 1;   /* make sure post_syscall runs */
 374                 repost = 1;
 375         }
 376 #endif /* NPROBE */
 377 
 378 #ifdef SYSCALLTRACE
 379         if (syscalltrace) {
 380                 int i;
 381                 long *ap;
 382                 char *cp;
 383                 char *sysname;
 384                 struct sysent *callp;
 385 
 386                 if (code >= NSYSCALL)
 387                         callp = &nosys_ent; /* nosys has no args */
 388                 else
 389                         callp = LWP_GETSYSENT(lwp) + code;
 390                 (void) save_syscall_args();
 391                 mutex_enter(&systrace_lock);
 392                 printf("%d: ", p->p_pid);
 393                 if (code >= NSYSCALL)
 394                         printf("0x%x", code);
 395                 else {
 396                         sysname = mod_getsysname(code);
 397                         printf("%s[0x%x/0x%p]", sysname == NULL ? "NULL" :
 398                             sysname, code, callp->sy_callc);
 399                 }
 400                 cp = "(";
 401                 for (i = 0, ap = lwp->lwp_ap; i < callp->sy_narg; i++, ap++) {
 402                         printf("%s%lx", cp, *ap);
 403                         cp = ", ";
 404                 }
 405                 if (i)
 406                         printf(")");
 407                 printf(" %s id=0x%p\n", PTOU(p)->u_comm, curthread);
 408                 mutex_exit(&systrace_lock);
 409         }
 410 #endif /* SYSCALLTRACE */
 411 
 412         /*
 413          * If there was a continuing reason for pre-syscall processing,
 414          * set the t_pre_sys flag for the next system call.
 415          */
 416         if (repost)
 417                 t->t_pre_sys = 1;
 418         lwp->lwp_error = 0;  /* for old drivers */
 419         lwp->lwp_badpriv = PRIV_NONE;
 420         return (0);
 421 }
 422 
 423 
 424 /*
 425  * Post-syscall processing.  Perform abnormal system call completion
 426  * actions such as /proc tracing, profiling, signals, preemption, etc.
 427  *
 428  * This routine is called only if t_post_sys, t_sig_check, or t_astflag is set.
 429  * Any condition requiring pre-syscall handling must set one of these.
 430  * If the condition is persistent, this routine will repost t_post_sys.
 431  */
 432 void
 433 post_syscall(long rval1, long rval2)
 434 {
 435         kthread_t *t = curthread;
 436         klwp_t *lwp = ttolwp(t);
 437         proc_t *p = ttoproc(t);
 438         struct regs *rp = lwptoregs(lwp);
 439         uint_t  error;
 440         uint_t  code = t->t_sysnum;
 441         int     repost = 0;
 442         int     proc_stop = 0;          /* non-zero if stopping */
 443         int     sigprof = 0;            /* non-zero if sending SIGPROF */
 444 
 445         t->t_post_sys = 0;
 446 
 447         error = lwp->lwp_errno;
 448 
 449         /*
 450          * Code can be zero if this is a new LWP returning after a forkall(),
 451          * other than the one which matches the one in the parent which called
 452          * forkall().  In these LWPs, skip most of post-syscall activity.
 453          */
 454         if (code == 0)
 455                 goto sig_check;
 456         /*
 457          * If the trace flag is set, mark the lwp to take a single-step trap
 458          * on return to user level (below). The x86 lcall interface and
 459          * sysenter has already done this, and turned off the flag, but
 460          * amd64 syscall interface has not.
 461          */
 462         if (rp->r_ps & PS_T) {
 463                 lwp->lwp_pcb.pcb_flags |= DEBUG_PENDING;
 464                 rp->r_ps &= ~PS_T;
 465                 aston(curthread);
 466         }
 467 
 468         /* put out audit record for this syscall */
 469         if (AU_AUDITING()) {
 470                 rval_t  rval;
 471 
 472                 /* XX64 -- truncation of 64-bit return values? */
 473                 rval.r_val1 = (int)rval1;
 474                 rval.r_val2 = (int)rval2;
 475                 audit_finish(T_SYSCALL, code, error, &rval);
 476                 repost = 1;
 477         }
 478 
 479         if (curthread->t_pdmsg != NULL) {
 480                 char *m = curthread->t_pdmsg;
 481 
 482                 uprintf("%s", m);
 483                 kmem_free(m, strlen(m) + 1);
 484                 curthread->t_pdmsg = NULL;
 485         }
 486 
 487         /*
 488          * If we're going to stop for /proc tracing, set the flag and
 489          * save the arguments so that the return values don't smash them.
 490          */
 491         if (PTOU(p)->u_systrap) {
 492                 if (prismember(&PTOU(p)->u_exitmask, code)) {
 493                         if (lwp_getdatamodel(lwp) == DATAMODEL_LP64)
 494                                 (void) save_syscall_args();
 495                         proc_stop = 1;
 496                 }
 497                 repost = 1;
 498         }
 499 
 500         /*
 501          * Similarly check to see if SIGPROF might be sent.
 502          */
 503         if (curthread->t_rprof != NULL &&
 504             curthread->t_rprof->rp_anystate != 0) {
 505                 if (lwp_getdatamodel(lwp) == DATAMODEL_LP64)
 506                         (void) save_syscall_args();
 507                 sigprof = 1;
 508         }
 509 
 510         if (lwp->lwp_eosys == NORMALRETURN) {
 511                 if (error == 0) {
 512 #ifdef SYSCALLTRACE
 513                         if (syscalltrace) {
 514                                 mutex_enter(&systrace_lock);
 515                                 printf(
 516                                     "%d: r_val1=0x%lx, r_val2=0x%lx, id 0x%p\n",
 517                                     p->p_pid, rval1, rval2, curthread);
 518                                 mutex_exit(&systrace_lock);
 519                         }
 520 #endif /* SYSCALLTRACE */
 521                         rp->r_ps &= ~PS_C;
 522                         rp->r_r0 = rval1;
 523                         rp->r_r1 = rval2;
 524                 } else {
 525                         int sig;
 526 #ifdef SYSCALLTRACE
 527                         if (syscalltrace) {
 528                                 mutex_enter(&systrace_lock);
 529                                 printf("%d: error=%d, id 0x%p\n",
 530                                     p->p_pid, error, curthread);
 531                                 mutex_exit(&systrace_lock);
 532                         }
 533 #endif /* SYSCALLTRACE */
 534                         if (error == EINTR && t->t_activefd.a_stale)
 535                                 error = EBADF;
 536                         if (error == EINTR &&
 537                             (sig = lwp->lwp_cursig) != 0 &&
 538                             sigismember(&PTOU(p)->u_sigrestart, sig) &&
 539                             PTOU(p)->u_signal[sig - 1] != SIG_DFL &&
 540                             PTOU(p)->u_signal[sig - 1] != SIG_IGN)
 541                                 error = ERESTART;
 542                         rp->r_r0 = error;
 543                         rp->r_ps |= PS_C;
 544                 }
 545         }
 546 
 547         /*
 548          * From the proc(4) manual page:
 549          * When exit from a system call is being traced, the traced process
 550          * stops on completion of the system call just prior to checking for
 551          * signals and returning to user level.  At this point all return
 552          * values have been stored into the traced process's saved registers.
 553          */
 554         if (proc_stop) {
 555                 mutex_enter(&p->p_lock);
 556                 if (PTOU(p)->u_systrap &&
 557                     prismember(&PTOU(p)->u_exitmask, code))
 558                         stop(PR_SYSEXIT, code);
 559                 mutex_exit(&p->p_lock);
 560         }
 561 
 562         /*
 563          * If we are the parent returning from a successful
 564          * vfork, wait for the child to exec or exit.
 565          * This code must be here and not in the bowels of the system
 566          * so that /proc can intercept exit from vfork in a timely way.
 567          */
 568         if (t->t_flag & T_VFPARENT) {
 569                 ASSERT(code == SYS_vfork || code == SYS_forksys);
 570                 ASSERT(rp->r_r1 == 0 && error == 0);
 571                 vfwait((pid_t)rval1);
 572                 t->t_flag &= ~T_VFPARENT;
 573         }
 574 
 575         /*
 576          * If profiling is active, bill the current PC in user-land
 577          * and keep reposting until profiling is disabled.
 578          */
 579         if (p->p_prof.pr_scale) {
 580                 if (lwp->lwp_oweupc)
 581                         profil_tick(rp->r_pc);
 582                 repost = 1;
 583         }
 584 
 585 sig_check:
 586         /*
 587          * Reset flag for next time.
 588          * We must do this after stopping on PR_SYSEXIT
 589          * because /proc uses the information in lwp_eosys.
 590          */
 591         lwp->lwp_eosys = NORMALRETURN;
 592         clear_stale_fd();
 593         t->t_flag &= ~T_FORKALL;
 594 
 595         if (t->t_astflag | t->t_sig_check) {
 596                 /*
 597                  * Turn off the AST flag before checking all the conditions that
 598                  * may have caused an AST.  This flag is on whenever a signal or
 599                  * unusual condition should be handled after the next trap or
 600                  * syscall.
 601                  */
 602                 astoff(t);
 603                 /*
 604                  * If a single-step trap occurred on a syscall (see trap())
 605                  * recognize it now.  Do this before checking for signals
 606                  * because deferred_singlestep_trap() may generate a SIGTRAP to
 607                  * the LWP or may otherwise mark the LWP to call issig(FORREAL).
 608                  */
 609                 if (lwp->lwp_pcb.pcb_flags & DEBUG_PENDING)
 610                         deferred_singlestep_trap((caddr_t)rp->r_pc);
 611 
 612                 t->t_sig_check = 0;
 613 
 614                 /*
 615                  * The following check is legal for the following reasons:
 616                  *      1) The thread we are checking, is ourselves, so there is
 617                  *         no way the proc can go away.
 618                  *      2) The only time we need to be protected by the
 619                  *         lock is if the binding is changed.
 620                  *
 621                  *      Note we will still take the lock and check the binding
 622                  *      if the condition was true without the lock held.  This
 623                  *      prevents lock contention among threads owned by the
 624                  *      same proc.
 625                  */
 626 
 627                 if (curthread->t_proc_flag & TP_CHANGEBIND) {
 628                         mutex_enter(&p->p_lock);
 629                         if (curthread->t_proc_flag & TP_CHANGEBIND) {
 630                                 timer_lwpbind();
 631                                 curthread->t_proc_flag &= ~TP_CHANGEBIND;
 632                         }
 633                         mutex_exit(&p->p_lock);
 634                 }
 635 
 636                 /*
 637                  * for kaio requests on the special kaio poll queue,
 638                  * copyout their results to user memory.
 639                  */
 640                 if (p->p_aio)
 641                         aio_cleanup(0);
 642                 /*
 643                  * If this LWP was asked to hold, call holdlwp(), which will
 644                  * stop.  holdlwps() sets this up and calls pokelwps() which
 645                  * sets the AST flag.
 646                  *
 647                  * Also check TP_EXITLWP, since this is used by fresh new LWPs
 648                  * through lwp_rtt().  That flag is set if the lwp_create(2)
 649                  * syscall failed after creating the LWP.
 650                  */
 651                 if (ISHOLD(p) || (t->t_proc_flag & TP_EXITLWP))
 652                         holdlwp();
 653 
 654                 /*
 655                  * All code that sets signals and makes ISSIG_PENDING
 656                  * evaluate true must set t_sig_check afterwards.
 657                  */
 658                 if (ISSIG_PENDING(t, lwp, p)) {
 659                         if (issig(FORREAL))
 660                                 psig();
 661                         t->t_sig_check = 1;  /* recheck next time */
 662                 }
 663 
 664                 if (sigprof) {
 665                         int nargs = (code > 0 && code < NSYSCALL)?
 666                             LWP_GETSYSENT(lwp)[code].sy_narg : 0;
 667                         realsigprof(code, nargs, error);
 668                         t->t_sig_check = 1;  /* recheck next time */
 669                 }
 670 
 671                 /*
 672                  * If a performance counter overflow interrupt was
 673                  * delivered *during* the syscall, then re-enable the
 674                  * AST so that we take a trip through trap() to cause
 675                  * the SIGEMT to be delivered.
 676                  */
 677                 if (lwp->lwp_pcb.pcb_flags & CPC_OVERFLOW)
 678                         aston(t);
 679 
 680                 /*
 681                  * /proc can't enable/disable the trace bit itself
 682                  * because that could race with the call gate used by
 683                  * system calls via "lcall". If that happened, an
 684                  * invalid EFLAGS would result. prstep()/prnostep()
 685                  * therefore schedule an AST for the purpose.
 686                  */
 687                 if (lwp->lwp_pcb.pcb_flags & REQUEST_STEP) {
 688                         lwp->lwp_pcb.pcb_flags &= ~REQUEST_STEP;
 689                         rp->r_ps |= PS_T;
 690                 }
 691                 if (lwp->lwp_pcb.pcb_flags & REQUEST_NOSTEP) {
 692                         lwp->lwp_pcb.pcb_flags &= ~REQUEST_NOSTEP;
 693                         rp->r_ps &= ~PS_T;
 694                 }
 695         }
 696 
 697         lwp->lwp_errno = 0;          /* clear error for next time */
 698 
 699 #ifndef NPROBE
 700         /* Kernel probe */
 701         if (tnf_tracing_active) {
 702                 TNF_PROBE_3(syscall_end, "syscall thread", /* CSTYLED */,
 703                     tnf_long,   rval1,          rval1,
 704                     tnf_long,   rval2,          rval2,
 705                     tnf_long,   errno,          (long)error);
 706                 repost = 1;
 707         }
 708 #endif /* NPROBE */
 709 
 710         /*
 711          * Set state to LWP_USER here so preempt won't give us a kernel
 712          * priority if it occurs after this point.  Call CL_TRAPRET() to
 713          * restore the user-level priority.
 714          *
 715          * It is important that no locks (other than spinlocks) be entered
 716          * after this point before returning to user mode (unless lwp_state
 717          * is set back to LWP_SYS).
 718          *
 719          * XXX Sampled times past this point are charged to the user.
 720          */
 721         lwp->lwp_state = LWP_USER;
 722 
 723         if (t->t_trapret) {
 724                 t->t_trapret = 0;
 725                 thread_lock(t);
 726                 CL_TRAPRET(t);
 727                 thread_unlock(t);
 728         }
 729         if (CPU->cpu_runrun || t->t_schedflag & TS_ANYWAITQ)
 730                 preempt();
 731         prunstop();
 732 
 733         lwp->lwp_errno = 0;          /* clear error for next time */
 734 
 735         /*
 736          * The thread lock must be held in order to clear sysnum and reset
 737          * lwp_ap atomically with respect to other threads in the system that
 738          * may be looking at the args via lwp_ap from get_syscall_args().
 739          */
 740 
 741         thread_lock(t);
 742         t->t_sysnum = 0;             /* no longer in a system call */
 743 
 744         if (lwp_getdatamodel(lwp) == DATAMODEL_NATIVE) {
 745 #if defined(_LP64)
 746                 /*
 747                  * In case the args were copied to the lwp, reset the
 748                  * pointer so the next syscall will have the right
 749                  * lwp_ap pointer.
 750                  */
 751                 lwp->lwp_ap = (long *)&rp->r_rdi;
 752         } else {
 753 #endif
 754                 lwp->lwp_ap = NULL;  /* reset on every syscall entry */
 755         }
 756         thread_unlock(t);
 757 
 758         lwp->lwp_argsaved = 0;
 759 
 760         /*
 761          * If there was a continuing reason for post-syscall processing,
 762          * set the t_post_sys flag for the next system call.
 763          */
 764         if (repost)
 765                 t->t_post_sys = 1;
 766 
 767         /*
 768          * If there is a ustack registered for this lwp, and the stack rlimit
 769          * has been altered, read in the ustack. If the saved stack rlimit
 770          * matches the bounds of the ustack, update the ustack to reflect
 771          * the new rlimit. If the new stack rlimit is RLIM_INFINITY, disable
 772          * stack checking by setting the size to 0.
 773          */
 774         if (lwp->lwp_ustack != 0 && lwp->lwp_old_stk_ctl != 0) {
 775                 rlim64_t new_size;
 776                 caddr_t top;
 777                 stack_t stk;
 778                 struct rlimit64 rl;
 779 
 780                 mutex_enter(&p->p_lock);
 781                 new_size = p->p_stk_ctl;
 782                 top = p->p_usrstack;
 783                 (void) rctl_rlimit_get(rctlproc_legacy[RLIMIT_STACK], p, &rl);
 784                 mutex_exit(&p->p_lock);
 785 
 786                 if (rl.rlim_cur == RLIM64_INFINITY)
 787                         new_size = 0;
 788 
 789                 if (copyin((stack_t *)lwp->lwp_ustack, &stk,
 790                     sizeof (stack_t)) == 0 &&
 791                     (stk.ss_size == lwp->lwp_old_stk_ctl ||
 792                     stk.ss_size == 0) &&
 793                     stk.ss_sp == top - stk.ss_size) {
 794                         stk.ss_sp = (void *)((uintptr_t)stk.ss_sp +
 795                             stk.ss_size - (uintptr_t)new_size);
 796                         stk.ss_size = new_size;
 797 
 798                         (void) copyout(&stk, (stack_t *)lwp->lwp_ustack,
 799                             sizeof (stack_t));
 800                 }
 801 
 802                 lwp->lwp_old_stk_ctl = 0;
 803         }
 804 }
 805 
 806 /*
 807  * Called from post_syscall() when a deferred singlestep is to be taken.
 808  */
 809 void
 810 deferred_singlestep_trap(caddr_t pc)
 811 {
 812         proc_t *p = ttoproc(curthread);
 813         klwp_t *lwp = ttolwp(curthread);
 814         pcb_t *pcb = &lwp->lwp_pcb;
 815         uint_t fault = 0;
 816         k_siginfo_t siginfo;
 817 
 818         bzero(&siginfo, sizeof (siginfo));
 819 
 820         /*
 821          * If both NORMAL_STEP and WATCH_STEP are in
 822          * effect, give precedence to WATCH_STEP.
 823          * If neither is set, user must have set the
 824          * PS_T bit in %efl; treat this as NORMAL_STEP.
 825          */
 826         if ((fault = undo_watch_step(&siginfo)) == 0 &&
 827             ((pcb->pcb_flags & NORMAL_STEP) ||
 828             !(pcb->pcb_flags & WATCH_STEP))) {
 829                 siginfo.si_signo = SIGTRAP;
 830                 siginfo.si_code = TRAP_TRACE;
 831                 siginfo.si_addr  = pc;
 832                 fault = FLTTRACE;
 833         }
 834         pcb->pcb_flags &= ~(DEBUG_PENDING|NORMAL_STEP|WATCH_STEP);
 835 
 836         if (fault) {
 837                 /*
 838                  * Remember the fault and fault adddress
 839                  * for real-time (SIGPROF) profiling.
 840                  */
 841                 lwp->lwp_lastfault = fault;
 842                 lwp->lwp_lastfaddr = siginfo.si_addr;
 843                 /*
 844                  * If a debugger has declared this fault to be an
 845                  * event of interest, stop the lwp.  Otherwise just
 846                  * deliver the associated signal.
 847                  */
 848                 if (prismember(&p->p_fltmask, fault) &&
 849                     stop_on_fault(fault, &siginfo) == 0)
 850                         siginfo.si_signo = 0;
 851         }
 852 
 853         if (siginfo.si_signo)
 854                 trapsig(&siginfo, 1);
 855 }
 856 
 857 /*
 858  * nonexistent system call-- signal lwp (may want to handle it)
 859  * flag error if lwp won't see signal immediately
 860  */
 861 int64_t
 862 nosys()
 863 {
 864         tsignal(curthread, SIGSYS);
 865         return (set_errno(ENOSYS));
 866 }
 867 
 868 /*
 869  * Execute a 32-bit system call on behalf of the current thread.
 870  */
 871 void
 872 dosyscall(void)
 873 {
 874         /*
 875          * Need space on the stack to store syscall arguments.
 876          */
 877         long            syscall_args[MAXSYSARGS];
 878         struct sysent   *se;
 879         int64_t         ret;
 880 
 881         syscall_mstate(LMS_TRAP, LMS_SYSTEM);
 882 
 883         ASSERT(curproc->p_model == DATAMODEL_ILP32);
 884 
 885         CPU_STATS_ENTER_K();
 886         CPU_STATS_ADDQ(CPU, sys, syscall, 1);
 887         CPU_STATS_EXIT_K();
 888 
 889         se = syscall_entry(curthread, syscall_args);
 890 
 891         /*
 892          * syscall_entry() copied all 8 arguments into syscall_args.
 893          */
 894         ret = se->sy_callc(syscall_args[0], syscall_args[1], syscall_args[2],
 895             syscall_args[3], syscall_args[4], syscall_args[5], syscall_args[6],
 896             syscall_args[7]);
 897 
 898         syscall_exit(curthread, (int)ret & 0xffffffffu, (int)(ret >> 32));
 899         syscall_mstate(LMS_SYSTEM, LMS_TRAP);
 900 }
 901 
 902 /*
 903  * Get the arguments to the current system call. See comment atop
 904  * save_syscall_args() regarding lwp_ap usage.
 905  */
 906 
 907 uint_t
 908 get_syscall_args(klwp_t *lwp, long *argp, int *nargsp)
 909 {
 910         kthread_t       *t = lwptot(lwp);
 911         ulong_t mask = 0xfffffffful;
 912         uint_t  code;
 913         long    *ap;
 914         int     nargs;
 915 
 916 #if defined(_LP64)
 917         if (lwp_getdatamodel(lwp) == DATAMODEL_LP64)
 918                 mask = 0xfffffffffffffffful;
 919 #endif
 920 
 921         /*
 922          * The thread lock must be held while looking at the arguments to ensure
 923          * they don't go away via post_syscall().
 924          * get_syscall_args() is the only routine to read them which is callable
 925          * outside the LWP in question and hence the only one that must be
 926          * synchronized in this manner.
 927          */
 928         thread_lock(t);
 929 
 930         code = t->t_sysnum;
 931         ap = lwp->lwp_ap;
 932 
 933         thread_unlock(t);
 934 
 935         if (code != 0 && code < NSYSCALL) {
 936                 nargs = LWP_GETSYSENT(lwp)[code].sy_narg;
 937 
 938                 ASSERT(nargs <= MAXSYSARGS);
 939 
 940                 *nargsp = nargs;
 941                 while (nargs-- > 0)
 942                         *argp++ = *ap++ & mask;
 943         } else {
 944                 *nargsp = 0;
 945         }
 946 
 947         return (code);
 948 }
 949 
 950 #ifdef _SYSCALL32_IMPL
 951 /*
 952  * Get the arguments to the current 32-bit system call.
 953  */
 954 uint_t
 955 get_syscall32_args(klwp_t *lwp, int *argp, int *nargsp)
 956 {
 957         long args[MAXSYSARGS];
 958         uint_t i, code;
 959 
 960         code = get_syscall_args(lwp, args, nargsp);
 961 
 962         for (i = 0; i != *nargsp; i++)
 963                 *argp++ = (int)args[i];
 964         return (code);
 965 }
 966 #endif
 967 
 968 /*
 969  * Save the system call arguments in a safe place.
 970  *
 971  * On the i386 kernel:
 972  *
 973  *      Copy the users args prior to changing the stack or stack pointer.
 974  *      This is so /proc will be able to get a valid copy of the
 975  *      args from the user stack even after the user stack has been changed.
 976  *      Note that the kernel stack copy of the args may also have been
 977  *      changed by a system call handler which takes C-style arguments.
 978  *
 979  *      Note that this may be called by stop() from trap().  In that case
 980  *      t_sysnum will be zero (syscall_exit clears it), so no args will be
 981  *      copied.
 982  *
 983  * On the amd64 kernel:
 984  *
 985  *      For 64-bit applications, lwp->lwp_ap normally points to %rdi..%r9
 986  *      in the reg structure. If the user is going to change the argument
 987  *      registers, rax, or the stack and might want to get the args (for
 988  *      /proc tracing), it must copy the args elsewhere via save_syscall_args().
 989  *
 990  *      For 32-bit applications, lwp->lwp_ap normally points to a copy of
 991  *      the system call arguments on the kernel stack made from the user
 992  *      stack.  Copy the args prior to change the stack or stack pointer.
 993  *      This is so /proc will be able to get a valid copy of the args
 994  *      from the user stack even after that stack has been changed.
 995  *
 996  *      This may be called from stop() even when we're not in a system call.
 997  *      Since there's no easy way to tell, this must be safe (not panic).
 998  *      If the copyins get data faults, return non-zero.
 999  */
1000 int
1001 save_syscall_args()
1002 {
1003         kthread_t       *t = curthread;
1004         klwp_t          *lwp = ttolwp(t);
1005         uint_t          code = t->t_sysnum;
1006         uint_t          nargs;
1007 
1008         if (lwp->lwp_argsaved || code == 0)
1009                 return (0);             /* args already saved or not needed */
1010 
1011         if (code >= NSYSCALL) {
1012                 nargs = 0;              /* illegal syscall */
1013         } else {
1014                 struct sysent *se = LWP_GETSYSENT(lwp);
1015                 struct sysent *callp = se + code;
1016 
1017                 nargs = callp->sy_narg;
1018                 if (LOADABLE_SYSCALL(callp) && nargs == 0) {
1019                         krwlock_t       *module_lock;
1020 
1021                         /*
1022                          * Find out how many arguments the system
1023                          * call uses.
1024                          *
1025                          * We have the property that loaded syscalls
1026                          * never change the number of arguments they
1027                          * use after they've been loaded once.  This
1028                          * allows us to stop for /proc tracing without
1029                          * holding the module lock.
1030                          * /proc is assured that sy_narg is valid.
1031                          */
1032                         module_lock = lock_syscall(se, code);
1033                         nargs = callp->sy_narg;
1034                         rw_exit(module_lock);
1035                 }
1036         }
1037 
1038         /*
1039          * Fetch the system call arguments.
1040          */
1041         if (nargs == 0)
1042                 goto out;
1043 
1044         ASSERT(nargs <= MAXSYSARGS);
1045 
1046         if (lwp_getdatamodel(lwp) == DATAMODEL_NATIVE) {
1047 #if defined(_LP64)
1048                 struct regs *rp = lwptoregs(lwp);
1049 
1050                 lwp->lwp_arg[0] = rp->r_rdi;
1051                 lwp->lwp_arg[1] = rp->r_rsi;
1052                 lwp->lwp_arg[2] = rp->r_rdx;
1053                 lwp->lwp_arg[3] = rp->r_rcx;
1054                 lwp->lwp_arg[4] = rp->r_r8;
1055                 lwp->lwp_arg[5] = rp->r_r9;
1056                 if (nargs > 6 && copyin_args(rp, &lwp->lwp_arg[6], nargs - 6))
1057                         return (-1);
1058         } else {
1059 #endif
1060                 if (COPYIN_ARGS32(lwptoregs(lwp), lwp->lwp_arg, nargs))
1061                         return (-1);
1062         }
1063 out:
1064         lwp->lwp_ap = lwp->lwp_arg;
1065         lwp->lwp_argsaved = 1;
1066         t->t_post_sys = 1;   /* so lwp_ap will be reset */
1067         return (0);
1068 }
1069 
1070 void
1071 reset_syscall_args(void)
1072 {
1073         ttolwp(curthread)->lwp_argsaved = 0;
1074 }
1075 
1076 /*
1077  * Call a system call which takes a pointer to the user args struct and
1078  * a pointer to the return values.  This is a bit slower than the standard
1079  * C arg-passing method in some cases.
1080  */
1081 int64_t
1082 syscall_ap(void)
1083 {
1084         uint_t  error;
1085         struct sysent *callp;
1086         rval_t  rval;
1087         kthread_t *t = curthread;
1088         klwp_t  *lwp = ttolwp(t);
1089         struct regs *rp = lwptoregs(lwp);
1090 
1091         callp = LWP_GETSYSENT(lwp) + t->t_sysnum;
1092 
1093 #if defined(__amd64)
1094         /*
1095          * If the arguments don't fit in registers %rdi-%r9, make sure they
1096          * have been copied to the lwp_arg array.
1097          */
1098         if (callp->sy_narg > 6 && save_syscall_args())
1099                 return ((int64_t)set_errno(EFAULT));
1100 #endif
1101 
1102         rval.r_val1 = 0;
1103         rval.r_val2 = rp->r_r1;
1104         lwp->lwp_error = 0;  /* for old drivers */
1105         error = (*(callp->sy_call))(lwp->lwp_ap, &rval);
1106         if (error)
1107                 return ((longlong_t)set_errno(error));
1108         return (rval.r_vals);
1109 }
1110 
1111 /*
1112  * Load system call module.
1113  *      Returns with pointer to held read lock for module.
1114  */
1115 static krwlock_t *
1116 lock_syscall(struct sysent *table, uint_t code)
1117 {
1118         krwlock_t       *module_lock;
1119         struct modctl   *modp;
1120         int             id;
1121         struct sysent   *callp;
1122 
1123         callp = table + code;
1124         module_lock = callp->sy_lock;
1125 
1126         /*
1127          * Optimization to only call modload if we don't have a loaded
1128          * syscall.
1129          */
1130         rw_enter(module_lock, RW_READER);
1131         if (LOADED_SYSCALL(callp))
1132                 return (module_lock);
1133         rw_exit(module_lock);
1134 
1135         for (;;) {
1136                 if ((id = modload("sys", syscallnames[code])) == -1)
1137                         break;
1138 
1139                 /*
1140                  * If we loaded successfully at least once, the modctl
1141                  * will still be valid, so we try to grab it by filename.
1142                  * If this call fails, it's because the mod_filename
1143                  * was changed after the call to modload() (mod_hold_by_name()
1144                  * is the likely culprit).  We can safely just take
1145                  * another lap if this is the case;  the modload() will
1146                  * change the mod_filename back to one by which we can
1147                  * find the modctl.
1148                  */
1149                 modp = mod_find_by_filename("sys", syscallnames[code]);
1150 
1151                 if (modp == NULL)
1152                         continue;
1153 
1154                 mutex_enter(&mod_lock);
1155 
1156                 if (!modp->mod_installed) {
1157                         mutex_exit(&mod_lock);
1158                         continue;
1159                 }
1160                 break;
1161         }
1162         rw_enter(module_lock, RW_READER);
1163 
1164         if (id != -1)
1165                 mutex_exit(&mod_lock);
1166 
1167         return (module_lock);
1168 }
1169 
1170 /*
1171  * Loadable syscall support.
1172  *      If needed, load the module, then reserve it by holding a read
1173  *      lock for the duration of the call.
1174  *      Later, if the syscall is not unloadable, it could patch the vector.
1175  */
1176 /*ARGSUSED*/
1177 int64_t
1178 loadable_syscall(
1179     long a0, long a1, long a2, long a3,
1180     long a4, long a5, long a6, long a7)
1181 {
1182         klwp_t *lwp = ttolwp(curthread);
1183         int64_t rval;
1184         struct sysent *callp;
1185         struct sysent *se = LWP_GETSYSENT(lwp);
1186         krwlock_t *module_lock;
1187         int code, error = 0;
1188         int64_t (*sy_call)();
1189 
1190         code = curthread->t_sysnum;
1191         callp = se + code;
1192 
1193         /*
1194          * Try to autoload the system call if necessary
1195          */
1196         module_lock = lock_syscall(se, code);
1197         THREAD_KPRI_RELEASE();  /* drop priority given by rw_enter */
1198 
1199         /*
1200          * we've locked either the loaded syscall or nosys
1201          */
1202 
1203         if (lwp_getdatamodel(lwp) == DATAMODEL_NATIVE) {
1204 #if defined(_LP64)
1205                 if (callp->sy_flags & SE_ARGC) {
1206                         sy_call = (int64_t (*)())callp->sy_call;
1207                         rval = (*sy_call)(a0, a1, a2, a3, a4, a5);
1208                 } else
1209                         rval = syscall_ap();
1210         } else {
1211 #endif
1212                 /*
1213                  * Now that it's loaded, make sure enough args were copied.
1214                  */
1215                 if (COPYIN_ARGS32(lwptoregs(lwp), lwp->lwp_ap, callp->sy_narg))
1216                         error = EFAULT;
1217                 if (error) {
1218                         rval = set_errno(error);
1219                 } else if (callp->sy_flags & SE_ARGC) {
1220                         sy_call = (int64_t (*)())callp->sy_call;
1221                         rval = (*sy_call)(lwp->lwp_ap[0], lwp->lwp_ap[1],
1222                             lwp->lwp_ap[2], lwp->lwp_ap[3], lwp->lwp_ap[4],
1223                             lwp->lwp_ap[5]);
1224                 } else
1225                         rval = syscall_ap();
1226         }
1227 
1228         THREAD_KPRI_REQUEST();  /* regain priority from read lock */
1229         rw_exit(module_lock);
1230         return (rval);
1231 }
1232 
1233 /*
1234  * Indirect syscall handled in libc on x86 architectures
1235  */
1236 int64_t
1237 indir()
1238 {
1239         return (nosys());
1240 }
1241 
1242 /*
1243  * set_errno - set an error return from the current system call.
1244  *      This could be a macro.
1245  *      This returns the value it is passed, so that the caller can
1246  *      use tail-recursion-elimination and do return (set_errno(ERRNO));
1247  */
1248 uint_t
1249 set_errno(uint_t error)
1250 {
1251         ASSERT(error != 0);             /* must not be used to clear errno */
1252 
1253         curthread->t_post_sys = 1;   /* have post_syscall do error return */
1254         return (ttolwp(curthread)->lwp_errno = error);
1255 }
1256 
1257 /*
1258  * set_proc_pre_sys - Set pre-syscall processing for entire process.
1259  */
1260 void
1261 set_proc_pre_sys(proc_t *p)
1262 {
1263         kthread_t       *t;
1264         kthread_t       *first;
1265 
1266         ASSERT(MUTEX_HELD(&p->p_lock));
1267 
1268         t = first = p->p_tlist;
1269         do {
1270                 t->t_pre_sys = 1;
1271         } while ((t = t->t_forw) != first);
1272 }
1273 
1274 /*
1275  * set_proc_post_sys - Set post-syscall processing for entire process.
1276  */
1277 void
1278 set_proc_post_sys(proc_t *p)
1279 {
1280         kthread_t       *t;
1281         kthread_t       *first;
1282 
1283         ASSERT(MUTEX_HELD(&p->p_lock));
1284 
1285         t = first = p->p_tlist;
1286         do {
1287                 t->t_post_sys = 1;
1288         } while ((t = t->t_forw) != first);
1289 }
1290 
1291 /*
1292  * set_proc_sys - Set pre- and post-syscall processing for entire process.
1293  */
1294 void
1295 set_proc_sys(proc_t *p)
1296 {
1297         kthread_t       *t;
1298         kthread_t       *first;
1299 
1300         ASSERT(MUTEX_HELD(&p->p_lock));
1301 
1302         t = first = p->p_tlist;
1303         do {
1304                 t->t_pre_sys = 1;
1305                 t->t_post_sys = 1;
1306         } while ((t = t->t_forw) != first);
1307 }
1308 
1309 /*
1310  * set_all_proc_sys - set pre- and post-syscall processing flags for all
1311  * user processes.
1312  *
1313  * This is needed when auditing, tracing, or other facilities which affect
1314  * all processes are turned on.
1315  */
1316 void
1317 set_all_proc_sys()
1318 {
1319         kthread_t       *t;
1320         kthread_t       *first;
1321 
1322         mutex_enter(&pidlock);
1323         t = first = curthread;
1324         do {
1325                 t->t_pre_sys = 1;
1326                 t->t_post_sys = 1;
1327         } while ((t = t->t_next) != first);
1328         mutex_exit(&pidlock);
1329 }
1330 
1331 /*
1332  * set_all_zone_usr_proc_sys - set pre- and post-syscall processing flags for
1333  * all user processes running in the zone of the current process
1334  *
1335  * This is needed when auditing, tracing, or other facilities which affect
1336  * all processes are turned on.
1337  */
1338 void
1339 set_all_zone_usr_proc_sys(zoneid_t zoneid)
1340 {
1341         proc_t      *p;
1342         kthread_t   *t;
1343 
1344         mutex_enter(&pidlock);
1345         for (p = practive; p != NULL; p = p->p_next) {
1346                 /* skip kernel and incomplete processes */
1347                 if (p->p_exec == NULLVP || p->p_as == &kas ||
1348                     p->p_stat == SIDL || p->p_stat == SZOMB ||
1349                     (p->p_flag & (SSYS | SEXITING | SEXITLWPS)))
1350                         continue;
1351                 /*
1352                  * Only processes in the given zone (eventually in
1353                  * all zones) are taken into account
1354                  */
1355                 if (zoneid == ALL_ZONES || p->p_zone->zone_id == zoneid) {
1356                         mutex_enter(&p->p_lock);
1357                         if ((t = p->p_tlist) == NULL) {
1358                                 mutex_exit(&p->p_lock);
1359                                 continue;
1360                         }
1361                         /*
1362                          * Set pre- and post-syscall processing flags
1363                          * for all threads of the process
1364                          */
1365                         do {
1366                                 t->t_pre_sys = 1;
1367                                 t->t_post_sys = 1;
1368                         } while (p->p_tlist != (t = t->t_forw));
1369                         mutex_exit(&p->p_lock);
1370                 }
1371         }
1372         mutex_exit(&pidlock);
1373 }
1374 
1375 /*
1376  * set_proc_ast - Set asynchronous service trap (AST) flag for all
1377  * threads in process.
1378  */
1379 void
1380 set_proc_ast(proc_t *p)
1381 {
1382         kthread_t       *t;
1383         kthread_t       *first;
1384 
1385         ASSERT(MUTEX_HELD(&p->p_lock));
1386 
1387         t = first = p->p_tlist;
1388         do {
1389                 aston(t);
1390         } while ((t = t->t_forw) != first);
1391 }