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Diffstat (limited to 'sys/kern/kern_sig.c')
| -rw-r--r-- | sys/kern/kern_sig.c | 2153 |
1 files changed, 2153 insertions, 0 deletions
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c new file mode 100644 index 0000000..8af0280 --- /dev/null +++ b/sys/kern/kern_sig.c @@ -0,0 +1,2153 @@ +/* + * 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 <sys/param.h> +#include <sys/kernel.h> +#include <sys/sysproto.h> +#include <sys/systm.h> +#include <sys/signalvar.h> +#include <sys/namei.h> +#include <sys/vnode.h> +#include <sys/event.h> +#include <sys/proc.h> +#include <sys/pioctl.h> +#include <sys/acct.h> +#include <sys/fcntl.h> +#include <sys/condvar.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/wait.h> +#include <sys/ktr.h> +#include <sys/ktrace.h> +#include <sys/resourcevar.h> +#include <sys/smp.h> +#include <sys/stat.h> +#include <sys/sx.h> +#include <sys/syslog.h> +#include <sys/sysent.h> +#include <sys/sysctl.h> +#include <sys/malloc.h> +#include <sys/unistd.h> + +#include <machine/cpu.h> + +#define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ + +static int coredump(struct thread *); +static int do_sigaction(struct proc *p, int sig, struct sigaction *act, + struct sigaction *oact, int old); +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 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(). + * + * MP SAFE. + */ +int +cursig(struct proc *p) +{ + + PROC_LOCK_ASSERT(p, MA_OWNED); + mtx_assert(&sched_lock, MA_NOTOWNED); + return (SIGPENDING(p) ? issignal(p) : 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) +{ + + PROC_LOCK_ASSERT(p, MA_OWNED); + mtx_lock_spin(&sched_lock); + if (SIGPENDING(p)) { + p->p_sflag |= PS_NEEDSIGCHK; + p->p_kse.ke_flags |= KEF_ASTPENDING; /* XXXKSE */ + } + 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); +} + +/* + * do_sigaction + * sigaction + * osigaction + */ +static int +do_sigaction(p, sig, act, oact, old) + struct proc *p; + register int sig; + struct sigaction *act, *oact; + int old; +{ + register struct sigacts *ps; + + 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_43 + if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || + ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old) + 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 + */ +/* ARGSUSED */ +int +sigaction(td, uap) + struct thread *td; + register struct sigaction_args *uap; +{ + struct proc *p = td->td_proc; + struct sigaction act, oact; + register struct sigaction *actp, *oactp; + int error; + + mtx_lock(&Giant); + + actp = (uap->act != NULL) ? &act : NULL; + oactp = (uap->oact != NULL) ? &oact : NULL; + if (actp) { + error = copyin(uap->act, actp, sizeof(act)); + if (error) + goto done2; + } + error = do_sigaction(p, uap->sig, actp, oactp, 0); + if (oactp && !error) { + error = copyout(oactp, uap->oact, sizeof(oact)); + } +done2: + mtx_unlock(&Giant); + return (error); +} + +#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ +#ifndef _SYS_SYSPROTO_H_ +struct osigaction_args { + int signum; + struct osigaction *nsa; + struct osigaction *osa; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +osigaction(td, uap) + struct thread *td; + register struct osigaction_args *uap; +{ + struct proc *p = td->td_proc; + 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; + + mtx_lock(&Giant); + + if (nsap) { + error = copyin(uap->nsa, &sa, sizeof(sa)); + if (error) + goto done2; + nsap->sa_handler = sa.sa_handler; + nsap->sa_flags = sa.sa_flags; + OSIG2SIG(sa.sa_mask, nsap->sa_mask); + } + error = do_sigaction(p, uap->signum, nsap, osap, 1); + 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)); + } +done2: + mtx_unlock(&Giant); + return (error); +} +#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 + */ +/* ARGSUSED */ +int +sigpending(td, uap) + struct thread *td; + struct sigpending_args *uap; +{ + struct proc *p = td->td_proc; + sigset_t siglist; + int error; + + mtx_lock(&Giant); + PROC_LOCK(p); + siglist = p->p_siglist; + PROC_UNLOCK(p); + mtx_unlock(&Giant); + error = copyout(&siglist, uap->set, sizeof(sigset_t)); + return(error); +} + +#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ +#ifndef _SYS_SYSPROTO_H_ +struct osigpending_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +osigpending(td, uap) + struct thread *td; + struct osigpending_args *uap; +{ + struct proc *p = td->td_proc; + + mtx_lock(&Giant); + PROC_LOCK(p); + SIG2OSIG(p->p_siglist, td->td_retval[0]); + PROC_UNLOCK(p); + mtx_unlock(&Giant); + 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 proc *p = td->td_proc; + 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 = do_sigaction(p, 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; +{ + struct proc *p = td->td_proc; + sigset_t mask; + register struct sigacts *ps; + int error; + + error = copyin(uap->sigmask, &mask, sizeof(mask)); + if (error) + return (error); + + /* + * 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((caddr_t) 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((caddr_t) 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; +{ + struct proc *p = td->td_proc; + stack_t ss; + int oonstack; + int error = 0; + + mtx_lock(&Giant); + + oonstack = sigonstack(cpu_getstack(td)); + + if (uap->oss != NULL) { + PROC_LOCK(p); + ss = p->p_sigstk; + ss.ss_flags = (p->p_flag & P_ALTSTACK) + ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; + PROC_UNLOCK(p); + if ((error = copyout(&ss, uap->oss, sizeof(stack_t))) != 0) + goto done2; + } + + if (uap->ss != NULL) { + if (oonstack) { + error = EPERM; + goto done2; + } + if ((error = copyin(uap->ss, &ss, sizeof(ss))) != 0) + 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. + */ +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_stat == SZOMB) { + 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 do_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 int prop; + register sig_t action; + struct thread *td; +#ifdef SMP + struct ksegrp *kg; +#endif + + 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; + } + + /* + * bring the priority of a process up if we want it to get + * killed in this lifetime. + * XXXKSE think if a better way to do this. + * + * What we need to do is see if there is a thread that will + * be able to accept the signal. e.g. + * FOREACH_THREAD_IN_PROC() { + * if runnable, we're done + * else pick one at random. + * } + */ + /* XXXKSE + * For now there is one thread per proc. + * Effectively select one sucker thread.. + */ + td = FIRST_THREAD_IN_PROC(p); + mtx_lock_spin(&sched_lock); + if ((p->p_ksegrp.kg_nice > NZERO) && (action == SIG_DFL) && + (prop & SA_KILL) && ((p->p_flag & P_TRACED) == 0)) + p->p_ksegrp.kg_nice = NZERO; /* XXXKSE */ + mtx_unlock_spin(&sched_lock); + + 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); + } + SIGADDSET(p->p_siglist, sig); + mtx_lock_spin(&sched_lock); + signotify(p); + + /* + * Defer further processing for signals which are held, + * except that stopped processes must be continued by SIGCONT. + */ + if (action == SIG_HOLD && (!(prop & SA_CONT) || p->p_stat != SSTOP)) { + mtx_unlock_spin(&sched_lock); + return; + } + + switch (p->p_stat) { + + case SSLEEP: + /* + * If process 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) + goto out; + /* + * Process is sleeping and traced... make it runnable + * so it can discover the signal in issignal() and stop + * for the parent. + */ + if (p->p_flag & P_TRACED) + goto run; + /* + * 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); + goto out; + } + /* + * When a sleeping process receives a stop + * signal, process immediately if possible. + * All other (caught or default) signals + * cause the process to run. + */ + if (prop & SA_STOP) { + if (action != SIG_DFL) + goto runfast; + /* + * If a child holding parent blocked, + * stopping could cause deadlock. + */ + if (p->p_flag & P_PPWAIT) + goto out; + mtx_unlock_spin(&sched_lock); + SIGDELSET(p->p_siglist, sig); + p->p_xstat = 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); + mtx_lock_spin(&sched_lock); + stop(p); + goto out; + } else + goto runfast; + /* NOTREACHED */ + + case SSTOP: + /* + * If traced process is already stopped, + * then no further action is necessary. + */ + if (p->p_flag & P_TRACED) + goto out; + + /* + * Kill signal always sets processes running. + */ + if (sig == SIGKILL) + 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, then it goes back to run state. + * Otherwise, process goes back to sleep state. + */ + if (action == SIG_DFL) + SIGDELSET(p->p_siglist, sig); + if (action == SIG_CATCH) + goto runfast; + /* + * XXXKSE + * do this for each thread. + */ + if (p->p_flag & P_KSES) { + mtx_assert(&sched_lock, + MA_OWNED | MA_NOTRECURSED); + FOREACH_THREAD_IN_PROC(p, td) { + if (td->td_wchan == NULL) { + setrunnable(td); /* XXXKSE */ + } else { + /* mark it as sleeping */ + } + } + } else { + p->p_flag |= P_CONTINUED; + wakeup((caddr_t)p->p_pptr); + if (td->td_wchan == NULL) + goto run; + p->p_stat = SSLEEP; + } + goto out; + } + + if (prop & SA_STOP) { + /* + * Already stopped, don't need to stop again. + * (If we did the shell could get confused.) + */ + SIGDELSET(p->p_siglist, sig); + goto out; + } + + /* + * If process is sleeping interruptibly, then simulate a + * wakeup so that when it is continued, it will be made + * runnable and can look at the signal. But don't make + * the process runnable, leave it stopped. + * XXXKSE should we wake ALL blocked threads? + */ + if (p->p_flag & P_KSES) { + FOREACH_THREAD_IN_PROC(p, td) { + if (td->td_wchan && (td->td_flags & TDF_SINTR)){ + if (td->td_flags & TDF_CVWAITQ) + cv_waitq_remove(td); + else + unsleep(td); /* XXXKSE */ + } + } + } else { + if (td->td_wchan && td->td_flags & TDF_SINTR) { + if (td->td_flags & TDF_CVWAITQ) + cv_waitq_remove(td); + else + unsleep(td); /* XXXKSE */ + } + } + goto out; + + default: + /* + * SRUN, SIDL, SZOMB do nothing with the signal, + * other than kicking ourselves if we are running. + * It will either never be noticed, or noticed very soon. + */ + if (p->p_stat == SRUN) { +#ifdef SMP + struct kse *ke; + struct thread *td = curthread; +/* we should only deliver to one thread.. but which one? */ + FOREACH_KSEGRP_IN_PROC(p, kg) { + FOREACH_KSE_IN_GROUP(kg, ke) { + if (ke->ke_thread == td) { + continue; + } + forward_signal(ke->ke_thread); + } + } +#endif + } + goto out; + } + /*NOTREACHED*/ + +runfast: + /* + * Raise priority to at least PUSER. + * XXXKSE Should we make them all run fast? + * Maybe just one would be enough? + */ + + if (FIRST_THREAD_IN_PROC(p)->td_priority > PUSER) { + FIRST_THREAD_IN_PROC(p)->td_priority = PUSER; + } +run: + /* If we jump here, sched_lock has to be owned. */ + mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED); + setrunnable(td); /* XXXKSE */ +out: + mtx_unlock_spin(&sched_lock); + + /* Once we get here, sched_lock should not be owned. */ + mtx_assert(&sched_lock, MA_NOTOWNED); +} + +/* + * 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(curproc)) + * postsig(sig); + */ +int +issignal(p) + register struct proc *p; +{ + sigset_t mask; + register int sig, prop; + + PROC_LOCK_ASSERT(p, MA_OWNED); + 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); + 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; + } + + /* + * Decide whether the signal should be returned. + * Return the signal's number, or fall through + * to clear it from the pending mask. + */ + switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { + + case (int)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; + 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); + 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 (int)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); + mtx_assert(&sched_lock, MA_OWNED); + p->p_stat = SSTOP; + p->p_flag &= ~P_WAITED; + wakeup((caddr_t)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 do_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; + } + (*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. + * + * XXX: VOP_GETATTR() here requires holding the vnode lock. + */ + +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; + + 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; + } + + /* 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) { + error = EFAULT; + goto out1; + } + 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; + +out1: + 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); +} |
