/* * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 * $FreeBSD$ */ #include "opt_compat.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined (__alpha__) && !defined(COMPAT_43) #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" #endif #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ static int coredump(struct thread *); static int do_sigprocmask(struct proc *p, int how, sigset_t *set, sigset_t *oset, int old); static char *expand_name(const char *, uid_t, pid_t); static int killpg1(struct thread *td, int sig, int pgid, int all); static int sig_ffs(sigset_t *set); static int sigprop(int sig); static void stop(struct proc *); static void tdsignal(struct thread *td, int sig, sig_t action); static int filt_sigattach(struct knote *kn); static void filt_sigdetach(struct knote *kn); static int filt_signal(struct knote *kn, long hint); struct filterops sig_filtops = { 0, filt_sigattach, filt_sigdetach, filt_signal }; static int kern_logsigexit = 1; SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, &kern_logsigexit, 0, "Log processes quitting on abnormal signals to syslog(3)"); /* * Policy -- Can ucred cr1 send SIGIO to process cr2? * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG * in the right situations. */ #define CANSIGIO(cr1, cr2) \ ((cr1)->cr_uid == 0 || \ (cr1)->cr_ruid == (cr2)->cr_ruid || \ (cr1)->cr_uid == (cr2)->cr_ruid || \ (cr1)->cr_ruid == (cr2)->cr_uid || \ (cr1)->cr_uid == (cr2)->cr_uid) int sugid_coredump; SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); static int do_coredump = 1; SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, &do_coredump, 0, "Enable/Disable coredumps"); /* * Signal properties and actions. * The array below categorizes the signals and their default actions * according to the following properties: */ #define SA_KILL 0x01 /* terminates process by default */ #define SA_CORE 0x02 /* ditto and coredumps */ #define SA_STOP 0x04 /* suspend process */ #define SA_TTYSTOP 0x08 /* ditto, from tty */ #define SA_IGNORE 0x10 /* ignore by default */ #define SA_CONT 0x20 /* continue if suspended */ #define SA_CANTMASK 0x40 /* non-maskable, catchable */ static int sigproptbl[NSIG] = { SA_KILL, /* SIGHUP */ SA_KILL, /* SIGINT */ SA_KILL|SA_CORE, /* SIGQUIT */ SA_KILL|SA_CORE, /* SIGILL */ SA_KILL|SA_CORE, /* SIGTRAP */ SA_KILL|SA_CORE, /* SIGABRT */ SA_KILL|SA_CORE, /* SIGEMT */ SA_KILL|SA_CORE, /* SIGFPE */ SA_KILL, /* SIGKILL */ SA_KILL|SA_CORE, /* SIGBUS */ SA_KILL|SA_CORE, /* SIGSEGV */ SA_KILL|SA_CORE, /* SIGSYS */ SA_KILL, /* SIGPIPE */ SA_KILL, /* SIGALRM */ SA_KILL, /* SIGTERM */ SA_IGNORE, /* SIGURG */ SA_STOP, /* SIGSTOP */ SA_STOP|SA_TTYSTOP, /* SIGTSTP */ SA_IGNORE|SA_CONT, /* SIGCONT */ SA_IGNORE, /* SIGCHLD */ SA_STOP|SA_TTYSTOP, /* SIGTTIN */ SA_STOP|SA_TTYSTOP, /* SIGTTOU */ SA_IGNORE, /* SIGIO */ SA_KILL, /* SIGXCPU */ SA_KILL, /* SIGXFSZ */ SA_KILL, /* SIGVTALRM */ SA_KILL, /* SIGPROF */ SA_IGNORE, /* SIGWINCH */ SA_IGNORE, /* SIGINFO */ SA_KILL, /* SIGUSR1 */ SA_KILL, /* SIGUSR2 */ }; /* * Determine signal that should be delivered to process p, the current * process, 0 if none. If there is a pending stop signal with default * action, the process stops in issignal(). * XXXKSE the check for a pending stop is not done under KSE * * MP SAFE. */ int cursig(struct thread *td) { struct proc *p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); mtx_assert(&sched_lock, MA_NOTOWNED); return (SIGPENDING(p) ? issignal(td) : 0); } /* * Arrange for ast() to handle unmasked pending signals on return to user * mode. This must be called whenever a signal is added to p_siglist or * unmasked in p_sigmask. */ void signotify(struct proc *p) { struct thread *td; struct ksegrp *kg; PROC_LOCK_ASSERT(p, MA_OWNED); mtx_lock_spin(&sched_lock); if (SIGPENDING(p)) { p->p_sflag |= PS_NEEDSIGCHK; /* XXXKSE for now punish all KSEs */ FOREACH_KSEGRP_IN_PROC(p, kg) { FOREACH_THREAD_IN_GROUP(kg, td) { td->td_flags |= TDF_ASTPENDING; } } } mtx_unlock_spin(&sched_lock); } static __inline int sigprop(int sig) { if (sig > 0 && sig < NSIG) return (sigproptbl[_SIG_IDX(sig)]); return (0); } static __inline int sig_ffs(sigset_t *set) { int i; for (i = 0; i < _SIG_WORDS; i++) if (set->__bits[i]) return (ffs(set->__bits[i]) + (i * 32)); return (0); } /* * kern_sigaction * sigaction * freebsd4_sigaction * osigaction */ int kern_sigaction(td, sig, act, oact, flags) struct thread *td; register int sig; struct sigaction *act, *oact; int flags; { register struct sigacts *ps; struct proc *p = td->td_proc; if (!_SIG_VALID(sig)) return (EINVAL); PROC_LOCK(p); ps = p->p_sigacts; if (oact) { oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; oact->sa_flags = 0; if (SIGISMEMBER(ps->ps_sigonstack, sig)) oact->sa_flags |= SA_ONSTACK; if (!SIGISMEMBER(ps->ps_sigintr, sig)) oact->sa_flags |= SA_RESTART; if (SIGISMEMBER(ps->ps_sigreset, sig)) oact->sa_flags |= SA_RESETHAND; if (SIGISMEMBER(ps->ps_signodefer, sig)) oact->sa_flags |= SA_NODEFER; if (SIGISMEMBER(ps->ps_siginfo, sig)) oact->sa_flags |= SA_SIGINFO; if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP) oact->sa_flags |= SA_NOCLDSTOP; if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT) oact->sa_flags |= SA_NOCLDWAIT; } if (act) { if ((sig == SIGKILL || sig == SIGSTOP) && act->sa_handler != SIG_DFL) { PROC_UNLOCK(p); return (EINVAL); } /* * Change setting atomically. */ ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); if (act->sa_flags & SA_SIGINFO) { ps->ps_sigact[_SIG_IDX(sig)] = (__sighandler_t *)act->sa_sigaction; SIGADDSET(ps->ps_siginfo, sig); } else { ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; SIGDELSET(ps->ps_siginfo, sig); } if (!(act->sa_flags & SA_RESTART)) SIGADDSET(ps->ps_sigintr, sig); else SIGDELSET(ps->ps_sigintr, sig); if (act->sa_flags & SA_ONSTACK) SIGADDSET(ps->ps_sigonstack, sig); else SIGDELSET(ps->ps_sigonstack, sig); if (act->sa_flags & SA_RESETHAND) SIGADDSET(ps->ps_sigreset, sig); else SIGDELSET(ps->ps_sigreset, sig); if (act->sa_flags & SA_NODEFER) SIGADDSET(ps->ps_signodefer, sig); else SIGDELSET(ps->ps_signodefer, sig); #ifdef COMPAT_SUNOS if (act->sa_flags & SA_USERTRAMP) SIGADDSET(ps->ps_usertramp, sig); else SIGDELSET(ps->ps_usertramp, sig); #endif if (sig == SIGCHLD) { if (act->sa_flags & SA_NOCLDSTOP) p->p_procsig->ps_flag |= PS_NOCLDSTOP; else p->p_procsig->ps_flag &= ~PS_NOCLDSTOP; if (act->sa_flags & SA_NOCLDWAIT) { /* * Paranoia: since SA_NOCLDWAIT is implemented * by reparenting the dying child to PID 1 (and * trust it to reap the zombie), PID 1 itself * is forbidden to set SA_NOCLDWAIT. */ if (p->p_pid == 1) p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; else p->p_procsig->ps_flag |= PS_NOCLDWAIT; } else p->p_procsig->ps_flag &= ~PS_NOCLDWAIT; if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) p->p_procsig->ps_flag |= PS_CLDSIGIGN; else p->p_procsig->ps_flag &= ~PS_CLDSIGIGN; } /* * Set bit in p_sigignore for signals that are set to SIG_IGN, * and for signals set to SIG_DFL where the default is to * ignore. However, don't put SIGCONT in p_sigignore, as we * have to restart the process. */ if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || (sigprop(sig) & SA_IGNORE && ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { /* never to be seen again */ SIGDELSET(p->p_siglist, sig); if (sig != SIGCONT) /* easier in psignal */ SIGADDSET(p->p_sigignore, sig); SIGDELSET(p->p_sigcatch, sig); } else { SIGDELSET(p->p_sigignore, sig); if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) SIGDELSET(p->p_sigcatch, sig); else SIGADDSET(p->p_sigcatch, sig); } #ifdef COMPAT_FREEBSD4 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || (flags & KSA_FREEBSD4) == 0) SIGDELSET(ps->ps_freebsd4, sig); else SIGADDSET(ps->ps_freebsd4, sig); #endif #ifdef COMPAT_43 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || (flags & KSA_OSIGSET) == 0) SIGDELSET(ps->ps_osigset, sig); else SIGADDSET(ps->ps_osigset, sig); #endif } PROC_UNLOCK(p); return (0); } #ifndef _SYS_SYSPROTO_H_ struct sigaction_args { int sig; struct sigaction *act; struct sigaction *oact; }; #endif /* * MPSAFE */ int sigaction(td, uap) struct thread *td; register struct sigaction_args *uap; { struct sigaction act, oact; register struct sigaction *actp, *oactp; int error; actp = (uap->act != NULL) ? &act : NULL; oactp = (uap->oact != NULL) ? &oact : NULL; if (actp) { error = copyin(uap->act, actp, sizeof(act)); if (error) return (error); } mtx_lock(&Giant); error = kern_sigaction(td, uap->sig, actp, oactp, 0); mtx_unlock(&Giant); if (oactp && !error) { error = copyout(oactp, uap->oact, sizeof(oact)); } return (error); } #ifdef COMPAT_FREEBSD4 #ifndef _SYS_SYSPROTO_H_ struct freebsd4_sigaction_args { int sig; struct sigaction *act; struct sigaction *oact; }; #endif /* * MPSAFE */ int freebsd4_sigaction(td, uap) struct thread *td; register struct freebsd4_sigaction_args *uap; { struct sigaction act, oact; register struct sigaction *actp, *oactp; int error; actp = (uap->act != NULL) ? &act : NULL; oactp = (uap->oact != NULL) ? &oact : NULL; if (actp) { error = copyin(uap->act, actp, sizeof(act)); if (error) return (error); } mtx_lock(&Giant); error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); mtx_unlock(&Giant); if (oactp && !error) { error = copyout(oactp, uap->oact, sizeof(oact)); } return (error); } #endif /* COMAPT_FREEBSD4 */ #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ #ifndef _SYS_SYSPROTO_H_ struct osigaction_args { int signum; struct osigaction *nsa; struct osigaction *osa; }; #endif /* * MPSAFE */ int osigaction(td, uap) struct thread *td; register struct osigaction_args *uap; { struct osigaction sa; struct sigaction nsa, osa; register struct sigaction *nsap, *osap; int error; if (uap->signum <= 0 || uap->signum >= ONSIG) return (EINVAL); nsap = (uap->nsa != NULL) ? &nsa : NULL; osap = (uap->osa != NULL) ? &osa : NULL; if (nsap) { error = copyin(uap->nsa, &sa, sizeof(sa)); if (error) return (error); nsap->sa_handler = sa.sa_handler; nsap->sa_flags = sa.sa_flags; OSIG2SIG(sa.sa_mask, nsap->sa_mask); } mtx_lock(&Giant); error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); mtx_unlock(&Giant); if (osap && !error) { sa.sa_handler = osap->sa_handler; sa.sa_flags = osap->sa_flags; SIG2OSIG(osap->sa_mask, sa.sa_mask); error = copyout(&sa, uap->osa, sizeof(sa)); } return (error); } #if !defined(__i386__) && !defined(__alpha__) /* Avoid replicating the same stub everywhere */ int osigreturn(td, uap) struct thread *td; struct osigreturn_args *uap; { return (nosys(td, (struct nosys_args *)uap)); } #endif #endif /* COMPAT_43 */ /* * Initialize signal state for process 0; * set to ignore signals that are ignored by default. */ void siginit(p) struct proc *p; { register int i; PROC_LOCK(p); for (i = 1; i <= NSIG; i++) if (sigprop(i) & SA_IGNORE && i != SIGCONT) SIGADDSET(p->p_sigignore, i); PROC_UNLOCK(p); } /* * Reset signals for an exec of the specified process. */ void execsigs(p) register struct proc *p; { register struct sigacts *ps; register int sig; /* * Reset caught signals. Held signals remain held * through p_sigmask (unless they were caught, * and are now ignored by default). */ PROC_LOCK_ASSERT(p, MA_OWNED); ps = p->p_sigacts; while (SIGNOTEMPTY(p->p_sigcatch)) { sig = sig_ffs(&p->p_sigcatch); SIGDELSET(p->p_sigcatch, sig); if (sigprop(sig) & SA_IGNORE) { if (sig != SIGCONT) SIGADDSET(p->p_sigignore, sig); SIGDELSET(p->p_siglist, sig); } ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; } /* * Reset stack state to the user stack. * Clear set of signals caught on the signal stack. */ p->p_sigstk.ss_flags = SS_DISABLE; p->p_sigstk.ss_size = 0; p->p_sigstk.ss_sp = 0; p->p_flag &= ~P_ALTSTACK; /* * Reset no zombies if child dies flag as Solaris does. */ p->p_procsig->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; } /* * do_sigprocmask() * * Manipulate signal mask. */ static int do_sigprocmask(p, how, set, oset, old) struct proc *p; int how; sigset_t *set, *oset; int old; { int error; PROC_LOCK(p); if (oset != NULL) *oset = p->p_sigmask; error = 0; if (set != NULL) { switch (how) { case SIG_BLOCK: SIG_CANTMASK(*set); SIGSETOR(p->p_sigmask, *set); break; case SIG_UNBLOCK: SIGSETNAND(p->p_sigmask, *set); signotify(p); break; case SIG_SETMASK: SIG_CANTMASK(*set); if (old) SIGSETLO(p->p_sigmask, *set); else p->p_sigmask = *set; signotify(p); break; default: error = EINVAL; break; } } PROC_UNLOCK(p); return (error); } /* * sigprocmask() - MP SAFE (XXXKSE not under KSE it isn't) */ #ifndef _SYS_SYSPROTO_H_ struct sigprocmask_args { int how; const sigset_t *set; sigset_t *oset; }; #endif int sigprocmask(td, uap) register struct thread *td; struct sigprocmask_args *uap; { struct proc *p = td->td_proc; sigset_t set, oset; sigset_t *setp, *osetp; int error; setp = (uap->set != NULL) ? &set : NULL; osetp = (uap->oset != NULL) ? &oset : NULL; if (setp) { error = copyin(uap->set, setp, sizeof(set)); if (error) return (error); } error = do_sigprocmask(p, uap->how, setp, osetp, 0); if (osetp && !error) { error = copyout(osetp, uap->oset, sizeof(oset)); } return (error); } #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ /* * osigprocmask() - MP SAFE */ #ifndef _SYS_SYSPROTO_H_ struct osigprocmask_args { int how; osigset_t mask; }; #endif int osigprocmask(td, uap) register struct thread *td; struct osigprocmask_args *uap; { struct proc *p = td->td_proc; sigset_t set, oset; int error; OSIG2SIG(uap->mask, set); error = do_sigprocmask(p, uap->how, &set, &oset, 1); SIG2OSIG(oset, td->td_retval[0]); return (error); } #endif /* COMPAT_43 */ #ifndef _SYS_SYSPROTO_H_ struct sigpending_args { sigset_t *set; }; #endif /* * MPSAFE */ int sigpending(td, uap) struct thread *td; struct sigpending_args *uap; { struct proc *p = td->td_proc; sigset_t siglist; PROC_LOCK(p); siglist = p->p_siglist; PROC_UNLOCK(p); return (copyout(&siglist, uap->set, sizeof(sigset_t))); } #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ #ifndef _SYS_SYSPROTO_H_ struct osigpending_args { int dummy; }; #endif /* * MPSAFE */ int osigpending(td, uap) struct thread *td; struct osigpending_args *uap; { struct proc *p = td->td_proc; PROC_LOCK(p); SIG2OSIG(p->p_siglist, td->td_retval[0]); PROC_UNLOCK(p); return (0); } #endif /* COMPAT_43 */ #if defined(COMPAT_43) || defined(COMPAT_SUNOS) /* * Generalized interface signal handler, 4.3-compatible. */ #ifndef _SYS_SYSPROTO_H_ struct osigvec_args { int signum; struct sigvec *nsv; struct sigvec *osv; }; #endif /* * MPSAFE */ /* ARGSUSED */ int osigvec(td, uap) struct thread *td; register struct osigvec_args *uap; { struct sigvec vec; struct sigaction nsa, osa; register struct sigaction *nsap, *osap; int error; if (uap->signum <= 0 || uap->signum >= ONSIG) return (EINVAL); nsap = (uap->nsv != NULL) ? &nsa : NULL; osap = (uap->osv != NULL) ? &osa : NULL; if (nsap) { error = copyin(uap->nsv, &vec, sizeof(vec)); if (error) return (error); nsap->sa_handler = vec.sv_handler; OSIG2SIG(vec.sv_mask, nsap->sa_mask); nsap->sa_flags = vec.sv_flags; nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ #ifdef COMPAT_SUNOS nsap->sa_flags |= SA_USERTRAMP; #endif } mtx_lock(&Giant); error = kern_sigaction(td, uap->signum, nsap, osap, 1); mtx_unlock(&Giant); if (osap && !error) { vec.sv_handler = osap->sa_handler; SIG2OSIG(osap->sa_mask, vec.sv_mask); vec.sv_flags = osap->sa_flags; vec.sv_flags &= ~SA_NOCLDWAIT; vec.sv_flags ^= SA_RESTART; #ifdef COMPAT_SUNOS vec.sv_flags &= ~SA_NOCLDSTOP; #endif error = copyout(&vec, uap->osv, sizeof(vec)); } return (error); } #ifndef _SYS_SYSPROTO_H_ struct osigblock_args { int mask; }; #endif /* * MPSAFE */ int osigblock(td, uap) register struct thread *td; struct osigblock_args *uap; { struct proc *p = td->td_proc; sigset_t set; OSIG2SIG(uap->mask, set); SIG_CANTMASK(set); mtx_lock(&Giant); PROC_LOCK(p); SIG2OSIG(p->p_sigmask, td->td_retval[0]); SIGSETOR(p->p_sigmask, set); PROC_UNLOCK(p); mtx_unlock(&Giant); return (0); } #ifndef _SYS_SYSPROTO_H_ struct osigsetmask_args { int mask; }; #endif /* * MPSAFE */ int osigsetmask(td, uap) struct thread *td; struct osigsetmask_args *uap; { struct proc *p = td->td_proc; sigset_t set; OSIG2SIG(uap->mask, set); SIG_CANTMASK(set); mtx_lock(&Giant); PROC_LOCK(p); SIG2OSIG(p->p_sigmask, td->td_retval[0]); SIGSETLO(p->p_sigmask, set); signotify(p); PROC_UNLOCK(p); mtx_unlock(&Giant); return (0); } #endif /* COMPAT_43 || COMPAT_SUNOS */ /* * Suspend process until signal, providing mask to be set * in the meantime. Note nonstandard calling convention: * libc stub passes mask, not pointer, to save a copyin. ***** XXXKSE this doesn't make sense under KSE. ***** Do we suspend the thread or all threads in the process? ***** How do we suspend threads running NOW on another processor? */ #ifndef _SYS_SYSPROTO_H_ struct sigsuspend_args { const sigset_t *sigmask; }; #endif /* * MPSAFE */ /* ARGSUSED */ int sigsuspend(td, uap) struct thread *td; struct sigsuspend_args *uap; { sigset_t mask; int error; error = copyin(uap->sigmask, &mask, sizeof(mask)); if (error) return (error); return (kern_sigsuspend(td, mask)); } int kern_sigsuspend(struct thread *td, sigset_t mask) { struct proc *p = td->td_proc; register struct sigacts *ps; /* * When returning from sigsuspend, we want * the old mask to be restored after the * signal handler has finished. Thus, we * save it here and mark the sigacts structure * to indicate this. */ mtx_lock(&Giant); PROC_LOCK(p); ps = p->p_sigacts; p->p_oldsigmask = p->p_sigmask; p->p_flag |= P_OLDMASK; SIG_CANTMASK(mask); p->p_sigmask = mask; signotify(p); while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) /* void */; PROC_UNLOCK(p); mtx_unlock(&Giant); /* always return EINTR rather than ERESTART... */ return (EINTR); } #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ #ifndef _SYS_SYSPROTO_H_ struct osigsuspend_args { osigset_t mask; }; #endif /* * MPSAFE */ /* ARGSUSED */ int osigsuspend(td, uap) struct thread *td; struct osigsuspend_args *uap; { struct proc *p = td->td_proc; sigset_t mask; register struct sigacts *ps; mtx_lock(&Giant); PROC_LOCK(p); ps = p->p_sigacts; p->p_oldsigmask = p->p_sigmask; p->p_flag |= P_OLDMASK; OSIG2SIG(uap->mask, mask); SIG_CANTMASK(mask); SIGSETLO(p->p_sigmask, mask); signotify(p); while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) /* void */; PROC_UNLOCK(p); mtx_unlock(&Giant); /* always return EINTR rather than ERESTART... */ return (EINTR); } #endif /* COMPAT_43 */ #if defined(COMPAT_43) || defined(COMPAT_SUNOS) #ifndef _SYS_SYSPROTO_H_ struct osigstack_args { struct sigstack *nss; struct sigstack *oss; }; #endif /* * MPSAFE */ /* ARGSUSED */ int osigstack(td, uap) struct thread *td; register struct osigstack_args *uap; { struct proc *p = td->td_proc; struct sigstack ss; int error = 0; mtx_lock(&Giant); if (uap->oss != NULL) { PROC_LOCK(p); ss.ss_sp = p->p_sigstk.ss_sp; ss.ss_onstack = sigonstack(cpu_getstack(td)); PROC_UNLOCK(p); error = copyout(&ss, uap->oss, sizeof(struct sigstack)); if (error) goto done2; } if (uap->nss != NULL) { if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0) goto done2; PROC_LOCK(p); p->p_sigstk.ss_sp = ss.ss_sp; p->p_sigstk.ss_size = 0; p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK; p->p_flag |= P_ALTSTACK; PROC_UNLOCK(p); } done2: mtx_unlock(&Giant); return (error); } #endif /* COMPAT_43 || COMPAT_SUNOS */ #ifndef _SYS_SYSPROTO_H_ struct sigaltstack_args { stack_t *ss; stack_t *oss; }; #endif /* * MPSAFE */ /* ARGSUSED */ int sigaltstack(td, uap) struct thread *td; register struct sigaltstack_args *uap; { stack_t ss, oss; int error; if (uap->ss != NULL) { error = copyin(uap->ss, &ss, sizeof(ss)); if (error) return (error); } error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, (uap->oss != NULL) ? &oss : NULL); if (error) return (error); if (uap->oss != NULL) error = copyout(&oss, uap->oss, sizeof(stack_t)); return (error); } int kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) { struct proc *p = td->td_proc; int oonstack; int error = 0; mtx_lock(&Giant); oonstack = sigonstack(cpu_getstack(td)); if (oss != NULL) { PROC_LOCK(p); *oss = p->p_sigstk; oss->ss_flags = (p->p_flag & P_ALTSTACK) ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; PROC_UNLOCK(p); } if (ss != NULL) { if (oonstack) { error = EPERM; goto done2; } if ((ss->ss_flags & ~SS_DISABLE) != 0) { error = EINVAL; goto done2; } if (!(ss->ss_flags & SS_DISABLE)) { if (ss->ss_size < p->p_sysent->sv_minsigstksz) { error = ENOMEM; goto done2; } PROC_LOCK(p); p->p_sigstk = *ss; p->p_flag |= P_ALTSTACK; PROC_UNLOCK(p); } else { PROC_LOCK(p); p->p_flag &= ~P_ALTSTACK; PROC_UNLOCK(p); } } done2: mtx_unlock(&Giant); return (error); } /* * Common code for kill process group/broadcast kill. * cp is calling process. */ static int killpg1(td, sig, pgid, all) register struct thread *td; int sig, pgid, all; { register struct proc *p; struct pgrp *pgrp; int nfound = 0; if (all) { /* * broadcast */ sx_slock(&allproc_lock); LIST_FOREACH(p, &allproc, p_list) { PROC_LOCK(p); if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || p == td->td_proc) { PROC_UNLOCK(p); continue; } if (p_cansignal(td, p, sig) == 0) { nfound++; if (sig) psignal(p, sig); } PROC_UNLOCK(p); } sx_sunlock(&allproc_lock); } else { sx_slock(&proctree_lock); if (pgid == 0) { /* * zero pgid means send to my process group. */ pgrp = td->td_proc->p_pgrp; PGRP_LOCK(pgrp); } else { pgrp = pgfind(pgid); if (pgrp == NULL) { sx_sunlock(&proctree_lock); return (ESRCH); } } sx_sunlock(&proctree_lock); LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { PROC_LOCK(p); if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { PROC_UNLOCK(p); continue; } if (p->p_state == PRS_ZOMBIE) { PROC_UNLOCK(p); continue; } if (p_cansignal(td, p, sig) == 0) { nfound++; if (sig) psignal(p, sig); } PROC_UNLOCK(p); } PGRP_UNLOCK(pgrp); } return (nfound ? 0 : ESRCH); } #ifndef _SYS_SYSPROTO_H_ struct kill_args { int pid; int signum; }; #endif /* * MPSAFE */ /* ARGSUSED */ int kill(td, uap) register struct thread *td; register struct kill_args *uap; { register struct proc *p; int error = 0; if ((u_int)uap->signum > _SIG_MAXSIG) return (EINVAL); mtx_lock(&Giant); if (uap->pid > 0) { /* kill single process */ if ((p = pfind(uap->pid)) == NULL) { error = ESRCH; } else if ((error = p_cansignal(td, p, uap->signum)) != 0) { PROC_UNLOCK(p); } else { if (uap->signum) psignal(p, uap->signum); PROC_UNLOCK(p); error = 0; } } else { switch (uap->pid) { case -1: /* broadcast signal */ error = killpg1(td, uap->signum, 0, 1); break; case 0: /* signal own process group */ error = killpg1(td, uap->signum, 0, 0); break; default: /* negative explicit process group */ error = killpg1(td, uap->signum, -uap->pid, 0); break; } } mtx_unlock(&Giant); return(error); } #if defined(COMPAT_43) || defined(COMPAT_SUNOS) #ifndef _SYS_SYSPROTO_H_ struct okillpg_args { int pgid; int signum; }; #endif /* * MPSAFE */ /* ARGSUSED */ int okillpg(td, uap) struct thread *td; register struct okillpg_args *uap; { int error; if ((u_int)uap->signum > _SIG_MAXSIG) return (EINVAL); mtx_lock(&Giant); error = killpg1(td, uap->signum, uap->pgid, 0); mtx_unlock(&Giant); return (error); } #endif /* COMPAT_43 || COMPAT_SUNOS */ /* * Send a signal to a process group. */ void gsignal(pgid, sig) int pgid, sig; { struct pgrp *pgrp; if (pgid != 0) { sx_slock(&proctree_lock); pgrp = pgfind(pgid); sx_sunlock(&proctree_lock); if (pgrp != NULL) { pgsignal(pgrp, sig, 0); PGRP_UNLOCK(pgrp); } } } /* * Send a signal to a process group. If checktty is 1, * limit to members which have a controlling terminal. */ void pgsignal(pgrp, sig, checkctty) struct pgrp *pgrp; int sig, checkctty; { register struct proc *p; if (pgrp) { PGRP_LOCK_ASSERT(pgrp, MA_OWNED); LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { PROC_LOCK(p); if (checkctty == 0 || p->p_flag & P_CONTROLT) psignal(p, sig); PROC_UNLOCK(p); } } } /* * Send a signal caused by a trap to the current process. * If it will be caught immediately, deliver it with correct code. * Otherwise, post it normally. * * MPSAFE */ void trapsignal(p, sig, code) struct proc *p; register int sig; u_long code; { register struct sigacts *ps = p->p_sigacts; PROC_LOCK(p); if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) && !SIGISMEMBER(p->p_sigmask, sig)) { p->p_stats->p_ru.ru_nsignals++; #ifdef KTRACE if (KTRPOINT(curthread, KTR_PSIG)) ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], &p->p_sigmask, code); #endif (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig, &p->p_sigmask, code); SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); if (!SIGISMEMBER(ps->ps_signodefer, sig)) SIGADDSET(p->p_sigmask, sig); if (SIGISMEMBER(ps->ps_sigreset, sig)) { /* * See kern_sigaction() for origin of this code. */ SIGDELSET(p->p_sigcatch, sig); if (sig != SIGCONT && sigprop(sig) & SA_IGNORE) SIGADDSET(p->p_sigignore, sig); ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; } } else { p->p_code = code; /* XXX for core dump/debugger */ p->p_sig = sig; /* XXX to verify code */ psignal(p, sig); } PROC_UNLOCK(p); } /* * Send the signal to the process. If the signal has an action, the action * is usually performed by the target process rather than the caller; we add * the signal to the set of pending signals for the process. * * Exceptions: * o When a stop signal is sent to a sleeping process that takes the * default action, the process is stopped without awakening it. * o SIGCONT restarts stopped processes (or puts them back to sleep) * regardless of the signal action (eg, blocked or ignored). * * Other ignored signals are discarded immediately. */ void psignal(p, sig) register struct proc *p; register int sig; { register sig_t action; struct thread *td; register int prop; KASSERT(_SIG_VALID(sig), ("psignal(): invalid signal %d\n", sig)); PROC_LOCK_ASSERT(p, MA_OWNED); KNOTE(&p->p_klist, NOTE_SIGNAL | sig); prop = sigprop(sig); /* * If proc is traced, always give parent a chance; * if signal event is tracked by procfs, give *that* * a chance, as well. */ if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) { action = SIG_DFL; } else { /* * If the signal is being ignored, * then we forget about it immediately. * (Note: we don't set SIGCONT in p_sigignore, * and if it is set to SIG_IGN, * action will be SIG_DFL here.) */ if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT)) return; if (SIGISMEMBER(p->p_sigmask, sig)) action = SIG_HOLD; else if (SIGISMEMBER(p->p_sigcatch, sig)) action = SIG_CATCH; else action = SIG_DFL; } if (prop & SA_CONT) SIG_STOPSIGMASK(p->p_siglist); if (prop & SA_STOP) { /* * If sending a tty stop signal to a member of an orphaned * process group, discard the signal here if the action * is default; don't stop the process below if sleeping, * and don't clear any pending SIGCONT. */ if ((prop & SA_TTYSTOP) && (p->p_pgrp->pg_jobc == 0) && (action == SIG_DFL)) return; SIG_CONTSIGMASK(p->p_siglist); p->p_flag &= ~P_CONTINUED; } SIGADDSET(p->p_siglist, sig); signotify(p); /* uses schedlock */ /* * Some signals have a process-wide effect and a per-thread * component. Most processing occurs when the process next * tries to cross the user boundary, however there are some * times when processing needs to be done immediatly, such as * waking up threads so that they can cross the user boundary. * We try do the per-process part here. */ if (P_SHOULDSTOP(p)) { /* * The process is in stopped mode. All the threads should be * either winding down or already on the suspended queue. */ if (p->p_flag & P_TRACED) { /* * The traced process is already stopped, * so no further action is necessary. * No signal can restart us. */ goto out; } if (sig == SIGKILL) { /* * SIGKILL sets process running. * It will die elsewhere. * All threads must be restarted. */ p->p_flag &= ~P_STOPPED; goto runfast; } if (prop & SA_CONT) { /* * If SIGCONT is default (or ignored), we continue the * process but don't leave the signal in p_siglist as * it has no further action. If SIGCONT is held, we * continue the process and leave the signal in * p_siglist. If the process catches SIGCONT, let it * handle the signal itself. If it isn't waiting on * an event, it goes back to run state. * Otherwise, process goes back to sleep state. */ p->p_flag &= ~P_STOPPED_SIG; p->p_flag |= P_CONTINUED; if (action == SIG_DFL) { SIGDELSET(p->p_siglist, sig); } else if (action == SIG_CATCH) { /* * The process wants to catch it so it needs * to run at least one thread, but which one? * It would seem that the answer would be to * run an upcall in the next KSE to run, and * deliver the signal that way. In a NON KSE * process, we need to make sure that the * single thread is runnable asap. * XXXKSE for now however, make them all run. */ goto runfast; } /* * The signal is not ignored or caught. */ mtx_lock_spin(&sched_lock); thread_unsuspend(p); mtx_unlock_spin(&sched_lock); goto out; } if (prop & SA_STOP) { /* * Already stopped, don't need to stop again * (If we did the shell could get confused). * Just make sure the signal STOP bit set. */ p->p_flag |= P_STOPPED_SIG; SIGDELSET(p->p_siglist, sig); goto out; } /* * All other kinds of signals: * If a thread is sleeping interruptibly, simulate a * wakeup so that when it is continued it will be made * runnable and can look at the signal. However, don't make * the PROCESS runnable, leave it stopped. * It may run a bit until it hits a thread_suspend_check(). */ mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td) { if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) { if (td->td_flags & TDF_CVWAITQ) cv_abort(td); else abortsleep(td); } } mtx_unlock_spin(&sched_lock); goto out; /* * XXXKSE What about threads that are waiting on mutexes? * Shouldn't they abort too? * No, hopefully mutexes are short lived.. They'll * eventually hit thread_suspend_check(). */ } else if (p->p_state == PRS_NORMAL) { if (prop & SA_CONT) { /* * Already active, don't need to start again. */ SIGDELSET(p->p_siglist, sig); goto out; } if ((p->p_flag & P_TRACED) || (action != SIG_DFL) || !(prop & SA_STOP)) { mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td) tdsignal(td, sig, action); mtx_unlock_spin(&sched_lock); goto out; } if (prop & SA_STOP) { if (p->p_flag & P_PPWAIT) goto out; mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td) { if (TD_IS_SLEEPING(td) && (td->td_flags & TDF_SINTR)) thread_suspend_one(td); } if (p->p_suspcount == p->p_numthreads) { mtx_unlock_spin(&sched_lock); stop(p); p->p_xstat = sig; SIGDELSET(p->p_siglist, sig); PROC_LOCK(p->p_pptr); if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) { psignal(p->p_pptr, SIGCHLD); } PROC_UNLOCK(p->p_pptr); } else { mtx_unlock_spin(&sched_lock); } goto out; } else goto runfast; /* NOTREACHED */ } else { /* Not in "NORMAL" state. discard the signal. */ SIGDELSET(p->p_siglist, sig); goto out; } /* * The process is not stopped so we need to apply the signal to all the * running threads. */ runfast: mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td) tdsignal(td, sig, action); thread_unsuspend(p); mtx_unlock_spin(&sched_lock); out: /* If we jump here, sched_lock should not be owned. */ mtx_assert(&sched_lock, MA_NOTOWNED); } /* * The force of a signal has been directed against a single * thread. We need to see what we can do about knocking it * out of any sleep it may be in etc. */ static void tdsignal(struct thread *td, int sig, sig_t action) { struct proc *p = td->td_proc; register int prop; mtx_assert(&sched_lock, MA_OWNED); prop = sigprop(sig); /* * Bring the priority of a thread up if we want it to get * killed in this lifetime. */ if ((action == SIG_DFL) && (prop & SA_KILL)) { if (td->td_priority > PUSER) { td->td_priority = PUSER; } } /* * Defer further processing for signals which are held, * except that stopped processes must be continued by SIGCONT. */ if (action == SIG_HOLD) { return; } if (TD_IS_SLEEPING(td)) { /* * If thread is sleeping uninterruptibly * we can't interrupt the sleep... the signal will * be noticed when the process returns through * trap() or syscall(). */ if ((td->td_flags & TDF_SINTR) == 0) { return; } /* * Process is sleeping and traced. Make it runnable * so it can discover the signal in issignal() and stop * for its parent. */ if (p->p_flag & P_TRACED) { p->p_flag &= ~P_STOPPED_TRACE; } else { /* * If SIGCONT is default (or ignored) and process is * asleep, we are finished; the process should not * be awakened. */ if ((prop & SA_CONT) && action == SIG_DFL) { SIGDELSET(p->p_siglist, sig); return; } /* * Raise priority to at least PUSER. */ if (td->td_priority > PUSER) { td->td_priority = PUSER; } } if (td->td_flags & TDF_CVWAITQ) cv_abort(td); else abortsleep(td); } #ifdef SMP else { /* * Other states do nothing with the signal immediatly, * other than kicking ourselves if we are running. * It will either never be noticed, or noticed very soon. */ if (TD_IS_RUNNING(td) && td != curthread) { forward_signal(td); } } #endif } /* * If the current process has received a signal (should be caught or cause * termination, should interrupt current syscall), return the signal number. * Stop signals with default action are processed immediately, then cleared; * they aren't returned. This is checked after each entry to the system for * a syscall or trap (though this can usually be done without calling issignal * by checking the pending signal masks in cursig.) The normal call * sequence is * * while (sig = cursig(curthread)) * postsig(sig); */ int issignal(td) struct thread *td; { struct proc *p; sigset_t mask; register int sig, prop; p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); WITNESS_SLEEP(1, &p->p_mtx.mtx_object); for (;;) { int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); mask = p->p_siglist; SIGSETNAND(mask, p->p_sigmask); if (p->p_flag & P_PPWAIT) SIG_STOPSIGMASK(mask); if (SIGISEMPTY(mask)) /* no signal to send */ return (0); sig = sig_ffs(&mask); prop = sigprop(sig); _STOPEVENT(p, S_SIG, sig); /* * We should see pending but ignored signals * only if P_TRACED was on when they were posted. */ if (SIGISMEMBER(p->p_sigignore, sig) && (traced == 0)) { SIGDELSET(p->p_siglist, sig); continue; } if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { /* * If traced, always stop. */ p->p_xstat = sig; PROC_LOCK(p->p_pptr); psignal(p->p_pptr, SIGCHLD); PROC_UNLOCK(p->p_pptr); mtx_lock_spin(&sched_lock); stop(p); /* uses schedlock too eventually */ thread_suspend_one(td); PROC_UNLOCK(p); DROP_GIANT(); p->p_stats->p_ru.ru_nivcsw++; mi_switch(); mtx_unlock_spin(&sched_lock); PICKUP_GIANT(); PROC_LOCK(p); /* * If the traced bit got turned off, go back up * to the top to rescan signals. This ensures * that p_sig* and ps_sigact are consistent. */ if ((p->p_flag & P_TRACED) == 0) continue; /* * If parent wants us to take the signal, * then it will leave it in p->p_xstat; * otherwise we just look for signals again. */ SIGDELSET(p->p_siglist, sig); /* clear old signal */ sig = p->p_xstat; if (sig == 0) continue; /* * Put the new signal into p_siglist. If the * signal is being masked, look for other signals. */ SIGADDSET(p->p_siglist, sig); if (SIGISMEMBER(p->p_sigmask, sig)) continue; signotify(p); } /* * Decide whether the signal should be returned. * Return the signal's number, or fall through * to clear it from the pending mask. */ switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { case (intptr_t)SIG_DFL: /* * Don't take default actions on system processes. */ if (p->p_pid <= 1) { #ifdef DIAGNOSTIC /* * Are you sure you want to ignore SIGSEGV * in init? XXX */ printf("Process (pid %lu) got signal %d\n", (u_long)p->p_pid, sig); #endif break; /* == ignore */ } /* * If there is a pending stop signal to process * with default action, stop here, * then clear the signal. However, * if process is member of an orphaned * process group, ignore tty stop signals. */ if (prop & SA_STOP) { if (p->p_flag & P_TRACED || (p->p_pgrp->pg_jobc == 0 && prop & SA_TTYSTOP)) break; /* == ignore */ p->p_xstat = sig; mtx_lock_spin(&sched_lock); if (p->p_suspcount+1 == p->p_numthreads) { mtx_unlock_spin(&sched_lock); PROC_LOCK(p->p_pptr); if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0) { psignal(p->p_pptr, SIGCHLD); } PROC_UNLOCK(p->p_pptr); mtx_lock_spin(&sched_lock); } stop(p); thread_suspend_one(td); PROC_UNLOCK(p); DROP_GIANT(); p->p_stats->p_ru.ru_nivcsw++; mi_switch(); mtx_unlock_spin(&sched_lock); PICKUP_GIANT(); PROC_LOCK(p); break; } else if (prop & SA_IGNORE) { /* * Except for SIGCONT, shouldn't get here. * Default action is to ignore; drop it. */ break; /* == ignore */ } else return (sig); /*NOTREACHED*/ case (intptr_t)SIG_IGN: /* * Masking above should prevent us ever trying * to take action on an ignored signal other * than SIGCONT, unless process is traced. */ if ((prop & SA_CONT) == 0 && (p->p_flag & P_TRACED) == 0) printf("issignal\n"); break; /* == ignore */ default: /* * This signal has an action, let * postsig() process it. */ return (sig); } SIGDELSET(p->p_siglist, sig); /* take the signal! */ } /* NOTREACHED */ } /* * Put the argument process into the stopped state and notify the parent * via wakeup. Signals are handled elsewhere. The process must not be * on the run queue. Must be called with the proc p locked and the scheduler * lock held. */ static void stop(p) register struct proc *p; { PROC_LOCK_ASSERT(p, MA_OWNED); p->p_flag |= P_STOPPED_SIG; p->p_flag &= ~P_WAITED; wakeup(p->p_pptr); } /* * Take the action for the specified signal * from the current set of pending signals. */ void postsig(sig) register int sig; { struct thread *td = curthread; register struct proc *p = td->td_proc; struct sigacts *ps; sig_t action; sigset_t returnmask; int code; KASSERT(sig != 0, ("postsig")); PROC_LOCK_ASSERT(p, MA_OWNED); ps = p->p_sigacts; SIGDELSET(p->p_siglist, sig); action = ps->ps_sigact[_SIG_IDX(sig)]; #ifdef KTRACE if (KTRPOINT(td, KTR_PSIG)) ktrpsig(sig, action, p->p_flag & P_OLDMASK ? &p->p_oldsigmask : &p->p_sigmask, 0); #endif _STOPEVENT(p, S_SIG, sig); if (action == SIG_DFL) { /* * Default action, where the default is to kill * the process. (Other cases were ignored above.) */ sigexit(td, sig); /* NOTREACHED */ } else { /* * If we get here, the signal must be caught. */ KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_sigmask, sig), ("postsig action")); /* * Set the new mask value and also defer further * occurrences of this signal. * * Special case: user has done a sigsuspend. Here the * current mask is not of interest, but rather the * mask from before the sigsuspend is what we want * restored after the signal processing is completed. */ if (p->p_flag & P_OLDMASK) { returnmask = p->p_oldsigmask; p->p_flag &= ~P_OLDMASK; } else returnmask = p->p_sigmask; SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); if (!SIGISMEMBER(ps->ps_signodefer, sig)) SIGADDSET(p->p_sigmask, sig); if (SIGISMEMBER(ps->ps_sigreset, sig)) { /* * See kern_sigaction() for origin of this code. */ SIGDELSET(p->p_sigcatch, sig); if (sig != SIGCONT && sigprop(sig) & SA_IGNORE) SIGADDSET(p->p_sigignore, sig); ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; } p->p_stats->p_ru.ru_nsignals++; if (p->p_sig != sig) { code = 0; } else { code = p->p_code; p->p_code = 0; p->p_sig = 0; } if (p->p_flag & P_KSES) thread_signal_add(curthread, sig); else (*p->p_sysent->sv_sendsig)(action, sig, &returnmask, code); } } /* * Kill the current process for stated reason. */ void killproc(p, why) struct proc *p; char *why; { PROC_LOCK_ASSERT(p, MA_OWNED); CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, p->p_comm); log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); psignal(p, SIGKILL); } /* * Force the current process to exit with the specified signal, dumping core * if appropriate. We bypass the normal tests for masked and caught signals, * allowing unrecoverable failures to terminate the process without changing * signal state. Mark the accounting record with the signal termination. * If dumping core, save the signal number for the debugger. Calls exit and * does not return. */ void sigexit(td, sig) struct thread *td; int sig; { struct proc *p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); p->p_acflag |= AXSIG; if (sigprop(sig) & SA_CORE) { p->p_sig = sig; /* * Log signals which would cause core dumps * (Log as LOG_INFO to appease those who don't want * these messages.) * XXX : Todo, as well as euid, write out ruid too */ PROC_UNLOCK(p); if (!mtx_owned(&Giant)) mtx_lock(&Giant); if (coredump(td) == 0) sig |= WCOREFLAG; if (kern_logsigexit) log(LOG_INFO, "pid %d (%s), uid %d: exited on signal %d%s\n", p->p_pid, p->p_comm, td->td_ucred ? td->td_ucred->cr_uid : -1, sig &~ WCOREFLAG, sig & WCOREFLAG ? " (core dumped)" : ""); } else { PROC_UNLOCK(p); if (!mtx_owned(&Giant)) mtx_lock(&Giant); } exit1(td, W_EXITCODE(0, sig)); /* NOTREACHED */ } static char corefilename[MAXPATHLEN+1] = {"%N.core"}; SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, sizeof(corefilename), "process corefile name format string"); /* * expand_name(name, uid, pid) * Expand the name described in corefilename, using name, uid, and pid. * corefilename is a printf-like string, with three format specifiers: * %N name of process ("name") * %P process id (pid) * %U user id (uid) * For example, "%N.core" is the default; they can be disabled completely * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". * This is controlled by the sysctl variable kern.corefile (see above). */ static char * expand_name(name, uid, pid) const char *name; uid_t uid; pid_t pid; { const char *format, *appendstr; char *temp; char buf[11]; /* Buffer for pid/uid -- max 4B */ size_t i, l, n; format = corefilename; temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); if (temp == NULL) return (NULL); for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { switch (format[i]) { case '%': /* Format character */ i++; switch (format[i]) { case '%': appendstr = "%"; break; case 'N': /* process name */ appendstr = name; break; case 'P': /* process id */ sprintf(buf, "%u", pid); appendstr = buf; break; case 'U': /* user id */ sprintf(buf, "%u", uid); appendstr = buf; break; default: appendstr = ""; log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); } l = strlen(appendstr); if ((n + l) >= MAXPATHLEN) goto toolong; memcpy(temp + n, appendstr, l); n += l; break; default: temp[n++] = format[i]; } } if (format[i] != '\0') goto toolong; return (temp); toolong: log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", (long)pid, name, (u_long)uid); free(temp, M_TEMP); return (NULL); } /* * Dump a process' core. The main routine does some * policy checking, and creates the name of the coredump; * then it passes on a vnode and a size limit to the process-specific * coredump routine if there is one; if there _is not_ one, it returns * ENOSYS; otherwise it returns the error from the process-specific routine. */ static int coredump(struct thread *td) { struct proc *p = td->td_proc; register struct vnode *vp; register struct ucred *cred = td->td_ucred; struct flock lf; struct nameidata nd; struct vattr vattr; int error, error1, flags; struct mount *mp; char *name; /* name of corefile */ off_t limit; PROC_LOCK(p); _STOPEVENT(p, S_CORE, 0); if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { PROC_UNLOCK(p); return (EFAULT); } /* * Note that the bulk of limit checking is done after * the corefile is created. The exception is if the limit * for corefiles is 0, in which case we don't bother * creating the corefile at all. This layout means that * a corefile is truncated instead of not being created, * if it is larger than the limit. */ limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; if (limit == 0) { PROC_UNLOCK(p); return 0; } PROC_UNLOCK(p); restart: name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); if (name == NULL) return (EINVAL); NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ flags = O_CREAT | FWRITE | O_NOFOLLOW; error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR); free(name, M_TEMP); if (error) return (error); NDFREE(&nd, NDF_ONLY_PNBUF); vp = nd.ni_vp; /* Don't dump to non-regular files or files with links. */ if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { VOP_UNLOCK(vp, 0, td); error = EFAULT; goto out2; } VOP_UNLOCK(vp, 0, td); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_WRLCK; error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK); if (error) goto out2; if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { lf.l_type = F_UNLCK; VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); if ((error = vn_close(vp, FWRITE, cred, td)) != 0) return (error); if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) return (error); goto restart; } VATTR_NULL(&vattr); vattr.va_size = 0; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); VOP_LEASE(vp, td, cred, LEASE_WRITE); VOP_SETATTR(vp, &vattr, cred, td); VOP_UNLOCK(vp, 0, td); PROC_LOCK(p); p->p_acflag |= ACORE; PROC_UNLOCK(p); error = p->p_sysent->sv_coredump ? p->p_sysent->sv_coredump(td, vp, limit) : ENOSYS; lf.l_type = F_UNLCK; VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); vn_finished_write(mp); out2: error1 = vn_close(vp, FWRITE, cred, td); if (error == 0) error = error1; return (error); } /* * Nonexistent system call-- signal process (may want to handle it). * Flag error in case process won't see signal immediately (blocked or ignored). */ #ifndef _SYS_SYSPROTO_H_ struct nosys_args { int dummy; }; #endif /* * MPSAFE */ /* ARGSUSED */ int nosys(td, args) struct thread *td; struct nosys_args *args; { struct proc *p = td->td_proc; mtx_lock(&Giant); PROC_LOCK(p); psignal(p, SIGSYS); PROC_UNLOCK(p); mtx_unlock(&Giant); return (ENOSYS); } /* * Send a SIGIO or SIGURG signal to a process or process group using * stored credentials rather than those of the current process. */ void pgsigio(sigiop, sig, checkctty) struct sigio **sigiop; int sig, checkctty; { struct sigio *sigio; SIGIO_LOCK(); sigio = *sigiop; if (sigio == NULL) { SIGIO_UNLOCK(); return; } if (sigio->sio_pgid > 0) { PROC_LOCK(sigio->sio_proc); if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) psignal(sigio->sio_proc, sig); PROC_UNLOCK(sigio->sio_proc); } else if (sigio->sio_pgid < 0) { struct proc *p; PGRP_LOCK(sigio->sio_pgrp); LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { PROC_LOCK(p); if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && (checkctty == 0 || (p->p_flag & P_CONTROLT))) psignal(p, sig); PROC_UNLOCK(p); } PGRP_UNLOCK(sigio->sio_pgrp); } SIGIO_UNLOCK(); } static int filt_sigattach(struct knote *kn) { struct proc *p = curproc; kn->kn_ptr.p_proc = p; kn->kn_flags |= EV_CLEAR; /* automatically set */ PROC_LOCK(p); SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); PROC_UNLOCK(p); return (0); } static void filt_sigdetach(struct knote *kn) { struct proc *p = kn->kn_ptr.p_proc; PROC_LOCK(p); SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); PROC_UNLOCK(p); } /* * signal knotes are shared with proc knotes, so we apply a mask to * the hint in order to differentiate them from process hints. This * could be avoided by using a signal-specific knote list, but probably * isn't worth the trouble. */ static int filt_signal(struct knote *kn, long hint) { if (hint & NOTE_SIGNAL) { hint &= ~NOTE_SIGNAL; if (kn->kn_id == hint) kn->kn_data++; } return (kn->kn_data != 0); }