kern_thr.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2003, Jeffrey Roberson <jeff@freebsd.org>
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice unmodified, this list of conditions, and the following
   12  *    disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   27  */
   28 
   29 #include <sys/cdefs.h>
   30 __FBSDID("$FreeBSD$");
   31 
   32 #include "opt_posix.h"
   33 #include "opt_hwpmc_hooks.h"
   34 #include <sys/param.h>
   35 #include <sys/kernel.h>
   36 #include <sys/lock.h>
   37 #include <sys/mutex.h>
   38 #include <sys/priv.h>
   39 #include <sys/proc.h>
   40 #include <sys/posix4.h>
   41 #include <sys/ptrace.h>
   42 #include <sys/racct.h>
   43 #include <sys/resourcevar.h>
   44 #include <sys/rwlock.h>
   45 #include <sys/sched.h>
   46 #include <sys/sysctl.h>
   47 #include <sys/smp.h>
   48 #include <sys/syscallsubr.h>
   49 #include <sys/sysent.h>
   50 #include <sys/systm.h>
   51 #include <sys/sysproto.h>
   52 #include <sys/signalvar.h>
   53 #include <sys/sysctl.h>
   54 #include <sys/ucontext.h>
   55 #include <sys/thr.h>
   56 #include <sys/rtprio.h>
   57 #include <sys/umtx.h>
   58 #include <sys/limits.h>
   59 #ifdef  HWPMC_HOOKS
   60 #include <sys/pmckern.h>
   61 #endif
   62 
   63 #include <machine/frame.h>
   64 
   65 #include <security/audit/audit.h>
   66 
   67 static SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0,
   68     "thread allocation");
   69 
   70 static int max_threads_per_proc = 1500;
   71 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW,
   72     &max_threads_per_proc, 0, "Limit on threads per proc");
   73 
   74 static int max_threads_hits;
   75 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD,
   76     &max_threads_hits, 0, "kern.threads.max_threads_per_proc hit count");
   77 
   78 #ifdef COMPAT_FREEBSD32
   79 
   80 static inline int
   81 suword_lwpid(void *addr, lwpid_t lwpid)
   82 {
   83         int error;
   84 
   85         if (SV_CURPROC_FLAG(SV_LP64))
   86                 error = suword(addr, lwpid);
   87         else
   88                 error = suword32(addr, lwpid);
   89         return (error);
   90 }
   91 
   92 #else
   93 #define suword_lwpid    suword
   94 #endif
   95 
   96 /*
   97  * System call interface.
   98  */
   99 
  100 struct thr_create_initthr_args {
  101         ucontext_t ctx;
  102         long *tid;
  103 };
  104 
  105 static int
  106 thr_create_initthr(struct thread *td, void *thunk)
  107 {
  108         struct thr_create_initthr_args *args;
  109 
  110         /* Copy out the child tid. */
  111         args = thunk;
  112         if (args->tid != NULL && suword_lwpid(args->tid, td->td_tid))
  113                 return (EFAULT);
  114 
  115         return (set_mcontext(td, &args->ctx.uc_mcontext));
  116 }
  117 
  118 int
  119 sys_thr_create(struct thread *td, struct thr_create_args *uap)
  120     /* ucontext_t *ctx, long *id, int flags */
  121 {
  122         struct thr_create_initthr_args args;
  123         int error;
  124 
  125         if ((error = copyin(uap->ctx, &args.ctx, sizeof(args.ctx))))
  126                 return (error);
  127         args.tid = uap->id;
  128         return (thread_create(td, NULL, thr_create_initthr, &args));
  129 }
  130 
  131 int
  132 sys_thr_new(struct thread *td, struct thr_new_args *uap)
  133     /* struct thr_param * */
  134 {
  135         struct thr_param param;
  136         int error;
  137 
  138         if (uap->param_size < 0 || uap->param_size > sizeof(param))
  139                 return (EINVAL);
  140         bzero(&param, sizeof(param));
  141         if ((error = copyin(uap->param, &param, uap->param_size)))
  142                 return (error);
  143         return (kern_thr_new(td, &param));
  144 }
  145 
  146 static int
  147 thr_new_initthr(struct thread *td, void *thunk)
  148 {
  149         stack_t stack;
  150         struct thr_param *param;
  151 
  152         /*
  153          * Here we copy out tid to two places, one for child and one
  154          * for parent, because pthread can create a detached thread,
  155          * if parent wants to safely access child tid, it has to provide
  156          * its storage, because child thread may exit quickly and
  157          * memory is freed before parent thread can access it.
  158          */
  159         param = thunk;
  160         if ((param->child_tid != NULL &&
  161             suword_lwpid(param->child_tid, td->td_tid)) ||
  162             (param->parent_tid != NULL &&
  163             suword_lwpid(param->parent_tid, td->td_tid)))
  164                 return (EFAULT);
  165 
  166         /* Set up our machine context. */
  167         stack.ss_sp = param->stack_base;
  168         stack.ss_size = param->stack_size;
  169         /* Set upcall address to user thread entry function. */
  170         cpu_set_upcall(td, param->start_func, param->arg, &stack);
  171         /* Setup user TLS address and TLS pointer register. */
  172         return (cpu_set_user_tls(td, param->tls_base));
  173 }
  174 
  175 int
  176 kern_thr_new(struct thread *td, struct thr_param *param)
  177 {
  178         struct rtprio rtp, *rtpp;
  179         int error;
  180 
  181         rtpp = NULL;
  182         if (param->rtp != 0) {
  183                 error = copyin(param->rtp, &rtp, sizeof(struct rtprio));
  184                 if (error)
  185                         return (error);
  186                 rtpp = &rtp;
  187         }
  188         return (thread_create(td, rtpp, thr_new_initthr, param));
  189 }
  190 
  191 int
  192 thread_create(struct thread *td, struct rtprio *rtp,
  193     int (*initialize_thread)(struct thread *, void *), void *thunk)
  194 {
  195         struct thread *newtd;
  196         struct proc *p;
  197         int error;
  198 
  199         p = td->td_proc;
  200 
  201         if (rtp != NULL) {
  202                 switch(rtp->type) {
  203                 case RTP_PRIO_REALTIME:
  204                 case RTP_PRIO_FIFO:
  205                         /* Only root can set scheduler policy */
  206                         if (priv_check(td, PRIV_SCHED_SETPOLICY) != 0)
  207                                 return (EPERM);
  208                         if (rtp->prio > RTP_PRIO_MAX)
  209                                 return (EINVAL);
  210                         break;
  211                 case RTP_PRIO_NORMAL:
  212                         rtp->prio = 0;
  213                         break;
  214                 default:
  215                         return (EINVAL);
  216                 }
  217         }
  218 
  219 #ifdef RACCT
  220         if (racct_enable) {
  221                 PROC_LOCK(p);
  222                 error = racct_add(p, RACCT_NTHR, 1);
  223                 PROC_UNLOCK(p);
  224                 if (error != 0)
  225                         return (EPROCLIM);
  226         }
  227 #endif
  228 
  229         /* Initialize our td */
  230         error = kern_thr_alloc(p, 0, &newtd);
  231         if (error)
  232                 goto fail;
  233 
  234         cpu_copy_thread(newtd, td);
  235 
  236         bzero(&newtd->td_startzero,
  237             __rangeof(struct thread, td_startzero, td_endzero));
  238         newtd->td_pflags2 = 0;
  239         newtd->td_errno = 0;
  240         bcopy(&td->td_startcopy, &newtd->td_startcopy,
  241             __rangeof(struct thread, td_startcopy, td_endcopy));
  242         newtd->td_proc = td->td_proc;
  243         newtd->td_rb_list = newtd->td_rbp_list = newtd->td_rb_inact = 0;
  244         thread_cow_get(newtd, td);
  245 
  246         error = initialize_thread(newtd, thunk);
  247         if (error != 0) {
  248                 thread_cow_free(newtd);
  249                 thread_free(newtd);
  250                 goto fail;
  251         }
  252 
  253         PROC_LOCK(p);
  254         p->p_flag |= P_HADTHREADS;
  255         thread_link(newtd, p);
  256         bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name));
  257         thread_lock(td);
  258         /* let the scheduler know about these things. */
  259         sched_fork_thread(td, newtd);
  260         thread_unlock(td);
  261         if (P_SHOULDSTOP(p))
  262                 newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
  263         if (p->p_ptevents & PTRACE_LWP)
  264                 newtd->td_dbgflags |= TDB_BORN;
  265 
  266         PROC_UNLOCK(p);
  267 #ifdef  HWPMC_HOOKS
  268         if (PMC_PROC_IS_USING_PMCS(p))
  269                 PMC_CALL_HOOK(newtd, PMC_FN_THR_CREATE, NULL);
  270         else if (PMC_SYSTEM_SAMPLING_ACTIVE())
  271                 PMC_CALL_HOOK_UNLOCKED(newtd, PMC_FN_THR_CREATE_LOG, NULL);
  272 #endif
  273 
  274         tidhash_add(newtd);
  275 
  276         thread_lock(newtd);
  277         if (rtp != NULL) {
  278                 if (!(td->td_pri_class == PRI_TIMESHARE &&
  279                       rtp->type == RTP_PRIO_NORMAL)) {
  280                         rtp_to_pri(rtp, newtd);
  281                         sched_prio(newtd, newtd->td_user_pri);
  282                 } /* ignore timesharing class */
  283         }
  284         TD_SET_CAN_RUN(newtd);
  285         sched_add(newtd, SRQ_BORING);
  286         thread_unlock(newtd);
  287 
  288         return (0);
  289 
  290 fail:
  291 #ifdef RACCT
  292         if (racct_enable) {
  293                 PROC_LOCK(p);
  294                 racct_sub(p, RACCT_NTHR, 1);
  295                 PROC_UNLOCK(p);
  296         }
  297 #endif
  298         return (error);
  299 }
  300 
  301 int
  302 sys_thr_self(struct thread *td, struct thr_self_args *uap)
  303     /* long *id */
  304 {
  305         int error;
  306 
  307         error = suword_lwpid(uap->id, (unsigned)td->td_tid);
  308         if (error == -1)
  309                 return (EFAULT);
  310         return (0);
  311 }
  312 
  313 int
  314 sys_thr_exit(struct thread *td, struct thr_exit_args *uap)
  315     /* long *state */
  316 {
  317 
  318         umtx_thread_exit(td);
  319 
  320         /* Signal userland that it can free the stack. */
  321         if ((void *)uap->state != NULL) {
  322                 suword_lwpid(uap->state, 1);
  323                 kern_umtx_wake(td, uap->state, INT_MAX, 0);
  324         }
  325 
  326         return (kern_thr_exit(td));
  327 }
  328 
  329 int
  330 kern_thr_exit(struct thread *td)
  331 {
  332         struct proc *p;
  333 
  334         p = td->td_proc;
  335 
  336         /*
  337          * If all of the threads in a process call this routine to
  338          * exit (e.g. all threads call pthread_exit()), exactly one
  339          * thread should return to the caller to terminate the process
  340          * instead of the thread.
  341          *
  342          * Checking p_numthreads alone is not sufficient since threads
  343          * might be committed to terminating while the PROC_LOCK is
  344          * dropped in either ptracestop() or while removing this thread
  345          * from the tidhash.  Instead, the p_pendingexits field holds
  346          * the count of threads in either of those states and a thread
  347          * is considered the "last" thread if all of the other threads
  348          * in a process are already terminating.
  349          */
  350         PROC_LOCK(p);
  351         if (p->p_numthreads == p->p_pendingexits + 1) {
  352                 /*
  353                  * Ignore attempts to shut down last thread in the
  354                  * proc.  This will actually call _exit(2) in the
  355                  * usermode trampoline when it returns.
  356                  */
  357                 PROC_UNLOCK(p);
  358                 return (0);
  359         }
  360 
  361         p->p_pendingexits++;
  362         td->td_dbgflags |= TDB_EXIT;
  363         if (p->p_ptevents & PTRACE_LWP)
  364                 ptracestop(td, SIGTRAP, NULL);
  365         PROC_UNLOCK(p);
  366         tidhash_remove(td);
  367         PROC_LOCK(p);
  368         p->p_pendingexits--;
  369 
  370         /*
  371          * The check above should prevent all other threads from this
  372          * process from exiting while the PROC_LOCK is dropped, so
  373          * there must be at least one other thread other than the
  374          * current thread.
  375          */
  376         KASSERT(p->p_numthreads > 1, ("too few threads"));
  377         racct_sub(p, RACCT_NTHR, 1);
  378         tdsigcleanup(td);
  379 
  380 #ifdef AUDIT
  381         AUDIT_SYSCALL_EXIT(0, td);
  382 #endif
  383 
  384         PROC_SLOCK(p);
  385         thread_stopped(p);
  386         thread_exit();
  387         /* NOTREACHED */
  388 }
  389 
  390 int
  391 sys_thr_kill(struct thread *td, struct thr_kill_args *uap)
  392     /* long id, int sig */
  393 {
  394         ksiginfo_t ksi;
  395         struct thread *ttd;
  396         struct proc *p;
  397         int error;
  398 
  399         p = td->td_proc;
  400         ksiginfo_init(&ksi);
  401         ksi.ksi_signo = uap->sig;
  402         ksi.ksi_code = SI_LWP;
  403         ksi.ksi_pid = p->p_pid;
  404         ksi.ksi_uid = td->td_ucred->cr_ruid;
  405         if (uap->id == -1) {
  406                 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
  407                         error = EINVAL;
  408                 } else {
  409                         error = ESRCH;
  410                         PROC_LOCK(p);
  411                         FOREACH_THREAD_IN_PROC(p, ttd) {
  412                                 if (ttd != td) {
  413                                         error = 0;
  414                                         if (uap->sig == 0)
  415                                                 break;
  416                                         tdksignal(ttd, uap->sig, &ksi);
  417                                 }
  418                         }
  419                         PROC_UNLOCK(p);
  420                 }
  421         } else {
  422                 error = 0;
  423                 ttd = tdfind((lwpid_t)uap->id, p->p_pid);
  424                 if (ttd == NULL)
  425                         return (ESRCH);
  426                 if (uap->sig == 0)
  427                         ;
  428                 else if (!_SIG_VALID(uap->sig))
  429                         error = EINVAL;
  430                 else 
  431                         tdksignal(ttd, uap->sig, &ksi);
  432                 PROC_UNLOCK(ttd->td_proc);
  433         }
  434         return (error);
  435 }
  436 
  437 int
  438 sys_thr_kill2(struct thread *td, struct thr_kill2_args *uap)
  439     /* pid_t pid, long id, int sig */
  440 {
  441         ksiginfo_t ksi;
  442         struct thread *ttd;
  443         struct proc *p;
  444         int error;
  445 
  446         AUDIT_ARG_SIGNUM(uap->sig);
  447 
  448         ksiginfo_init(&ksi);
  449         ksi.ksi_signo = uap->sig;
  450         ksi.ksi_code = SI_LWP;
  451         ksi.ksi_pid = td->td_proc->p_pid;
  452         ksi.ksi_uid = td->td_ucred->cr_ruid;
  453         if (uap->id == -1) {
  454                 if ((p = pfind(uap->pid)) == NULL)
  455                         return (ESRCH);
  456                 AUDIT_ARG_PROCESS(p);
  457                 error = p_cansignal(td, p, uap->sig);
  458                 if (error) {
  459                         PROC_UNLOCK(p);
  460                         return (error);
  461                 }
  462                 if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
  463                         error = EINVAL;
  464                 } else {
  465                         error = ESRCH;
  466                         FOREACH_THREAD_IN_PROC(p, ttd) {
  467                                 if (ttd != td) {
  468                                         error = 0;
  469                                         if (uap->sig == 0)
  470                                                 break;
  471                                         tdksignal(ttd, uap->sig, &ksi);
  472                                 }
  473                         }
  474                 }
  475                 PROC_UNLOCK(p);
  476         } else {
  477                 ttd = tdfind((lwpid_t)uap->id, uap->pid);
  478                 if (ttd == NULL)
  479                         return (ESRCH);
  480                 p = ttd->td_proc;
  481                 AUDIT_ARG_PROCESS(p);
  482                 error = p_cansignal(td, p, uap->sig);
  483                 if (uap->sig == 0)
  484                         ;
  485                 else if (!_SIG_VALID(uap->sig))
  486                         error = EINVAL;
  487                 else
  488                         tdksignal(ttd, uap->sig, &ksi);
  489                 PROC_UNLOCK(p);
  490         }
  491         return (error);
  492 }
  493 
  494 int
  495 sys_thr_suspend(struct thread *td, struct thr_suspend_args *uap)
  496         /* const struct timespec *timeout */
  497 {
  498         struct timespec ts, *tsp;
  499         int error;
  500 
  501         tsp = NULL;
  502         if (uap->timeout != NULL) {
  503                 error = umtx_copyin_timeout(uap->timeout, &ts);
  504                 if (error != 0)
  505                         return (error);
  506                 tsp = &ts;
  507         }
  508 
  509         return (kern_thr_suspend(td, tsp));
  510 }
  511 
  512 int
  513 kern_thr_suspend(struct thread *td, struct timespec *tsp)
  514 {
  515         struct proc *p = td->td_proc;
  516         struct timeval tv;
  517         int error = 0;
  518         int timo = 0;
  519 
  520         if (td->td_pflags & TDP_WAKEUP) {
  521                 td->td_pflags &= ~TDP_WAKEUP;
  522                 return (0);
  523         }
  524 
  525         if (tsp != NULL) {
  526                 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
  527                         error = EWOULDBLOCK;
  528                 else {
  529                         TIMESPEC_TO_TIMEVAL(&tv, tsp);
  530                         timo = tvtohz(&tv);
  531                 }
  532         }
  533 
  534         PROC_LOCK(p);
  535         if (error == 0 && (td->td_flags & TDF_THRWAKEUP) == 0)
  536                 error = msleep((void *)td, &p->p_mtx,
  537                          PCATCH, "lthr", timo);
  538 
  539         if (td->td_flags & TDF_THRWAKEUP) {
  540                 thread_lock(td);
  541                 td->td_flags &= ~TDF_THRWAKEUP;
  542                 thread_unlock(td);
  543                 PROC_UNLOCK(p);
  544                 return (0);
  545         }
  546         PROC_UNLOCK(p);
  547         if (error == EWOULDBLOCK)
  548                 error = ETIMEDOUT;
  549         else if (error == ERESTART) {
  550                 if (timo != 0)
  551                         error = EINTR;
  552         }
  553         return (error);
  554 }
  555 
  556 int
  557 sys_thr_wake(struct thread *td, struct thr_wake_args *uap)
  558         /* long id */
  559 {
  560         struct proc *p;
  561         struct thread *ttd;
  562 
  563         if (uap->id == td->td_tid) {
  564                 td->td_pflags |= TDP_WAKEUP;
  565                 return (0);
  566         } 
  567 
  568         p = td->td_proc;
  569         ttd = tdfind((lwpid_t)uap->id, p->p_pid);
  570         if (ttd == NULL)
  571                 return (ESRCH);
  572         thread_lock(ttd);
  573         ttd->td_flags |= TDF_THRWAKEUP;
  574         thread_unlock(ttd);
  575         wakeup((void *)ttd);
  576         PROC_UNLOCK(p);
  577         return (0);
  578 }
  579 
  580 int
  581 sys_thr_set_name(struct thread *td, struct thr_set_name_args *uap)
  582 {
  583         struct proc *p;
  584         char name[MAXCOMLEN + 1];
  585         struct thread *ttd;
  586         int error;
  587 
  588         error = 0;
  589         name[0] = '\0';
  590         if (uap->name != NULL) {
  591                 error = copyinstr(uap->name, name, sizeof(name), NULL);
  592                 if (error == ENAMETOOLONG) {
  593                         error = copyin(uap->name, name, sizeof(name) - 1);
  594                         name[sizeof(name) - 1] = '\0';
  595                 }
  596                 if (error)
  597                         return (error);
  598         }
  599         p = td->td_proc;
  600         ttd = tdfind((lwpid_t)uap->id, p->p_pid);
  601         if (ttd == NULL)
  602                 return (ESRCH);
  603         strcpy(ttd->td_name, name);
  604 #ifdef HWPMC_HOOKS
  605         if (PMC_PROC_IS_USING_PMCS(p) || PMC_SYSTEM_SAMPLING_ACTIVE())
  606                 PMC_CALL_HOOK_UNLOCKED(ttd, PMC_FN_THR_CREATE_LOG, NULL);
  607 #endif
  608 #ifdef KTR
  609         sched_clear_tdname(ttd);
  610 #endif
  611         PROC_UNLOCK(p);
  612         return (error);
  613 }
  614 
  615 int
  616 kern_thr_alloc(struct proc *p, int pages, struct thread **ntd)
  617 {
  618 
  619         /* Have race condition but it is cheap. */
  620         if (p->p_numthreads >= max_threads_per_proc) {
  621                 ++max_threads_hits;
  622                 return (EPROCLIM);
  623         }
  624 
  625         *ntd = thread_alloc(pages);
  626         if (*ntd == NULL)
  627                 return (ENOMEM);
  628 
  629         return (0);
  630 }
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This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/kern/kern_thr.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_thr.c
