X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/1e3738dae86d0c042a0b649870762a9e2e6158c5..a18538c92b3fbcaa835cae4bc38a5b50faa13519:/usr/src/sys/kern/kern_sig.c diff --git a/usr/src/sys/kern/kern_sig.c b/usr/src/sys/kern/kern_sig.c index 4cf8e02f03..9a2fc94217 100644 --- a/usr/src/sys/kern/kern_sig.c +++ b/usr/src/sys/kern/kern_sig.c @@ -1,292 +1,704 @@ -/* kern_sig.c 5.5 82/09/04 */ - -#include "../h/param.h" -#include "../h/systm.h" -#include "../h/dir.h" -#include "../h/user.h" -#include "../h/reg.h" -#include "../h/inode.h" -#include "../h/proc.h" -#include "../h/mtpr.h" -#include "../h/timeb.h" -#include "../h/times.h" -#include "../h/conf.h" -#include "../h/buf.h" -#include "../h/mount.h" -#include "../h/text.h" -#include "../h/seg.h" -#include "../h/pte.h" -#include "../h/psl.h" -#include "../h/vm.h" -#include "../h/acct.h" -#include "../h/uio.h" - -/* KILL CODE SHOULDNT KNOW ABOUT PROCESS INTERNALS !?! */ - -sigvec() -{ +/* + * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California. + * All rights reserved. + * + * %sccs.include.redist.c% + * + * @(#)kern_sig.c 7.50 (Berkeley) %G% + */ -} +#define SIGPROP /* include signal properties table */ +#include "param.h" +#include "signalvar.h" +#include "resourcevar.h" +#include "namei.h" +#include "vnode.h" +#include "proc.h" +#include "systm.h" +#include "timeb.h" +#include "times.h" +#include "buf.h" +#include "acct.h" +#include "file.h" +#include "kernel.h" +#include "wait.h" +#include "ktrace.h" + +#include "machine/cpu.h" + +#include "vm/vm.h" +#include "kinfo_proc.h" +#include "user.h" /* for coredump */ + +/* + * Can process p, with pcred pc, send the signal signo to process q? + */ +#define CANSIGNAL(p, pc, q, signo) \ + ((pc)->pc_ucred->cr_uid == 0 || \ + (pc)->p_ruid == (q)->p_cred->p_ruid || \ + (pc)->pc_ucred->cr_uid == (q)->p_cred->p_ruid || \ + (pc)->p_ruid == (q)->p_ucred->cr_uid || \ + (pc)->pc_ucred->cr_uid == (q)->p_ucred->cr_uid || \ + ((signo) == SIGCONT && (q)->p_session == (p)->p_session)) -sigblock() +struct sigaction_args { + int signo; + struct sigaction *nsa; + struct sigaction *osa; +}; +/* ARGSUSED */ +sigaction(p, uap, retval) + struct proc *p; + register struct sigaction_args *uap; + int *retval; { + struct sigaction vec; + register struct sigaction *sa; + register struct sigacts *ps = p->p_sigacts; + register int sig; + int bit, error; + sig = uap->signo; + if (sig <= 0 || sig >= NSIG || sig == SIGKILL || sig == SIGSTOP) + return (EINVAL); + sa = &vec; + if (uap->osa) { + sa->sa_handler = ps->ps_sigact[sig]; + sa->sa_mask = ps->ps_catchmask[sig]; + bit = sigmask(sig); + sa->sa_flags = 0; + if ((ps->ps_sigonstack & bit) != 0) + sa->sa_flags |= SA_ONSTACK; + if ((ps->ps_sigintr & bit) == 0) + sa->sa_flags |= SA_RESTART; + if (p->p_flag & SNOCLDSTOP) + sa->sa_flags |= SA_NOCLDSTOP; + if (error = copyout((caddr_t)sa, (caddr_t)uap->osa, + sizeof (vec))) + return (error); + } + if (uap->nsa) { + if (error = copyin((caddr_t)uap->nsa, (caddr_t)sa, + sizeof (vec))) + return (error); + setsigvec(p, sig, sa); + } + return (0); } -sigsetmask() +setsigvec(p, sig, sa) + register struct proc *p; + int sig; + register struct sigaction *sa; { + register struct sigacts *ps = p->p_sigacts; + register int bit; + bit = sigmask(sig); + /* + * Change setting atomically. + */ + (void) splhigh(); + ps->ps_sigact[sig] = sa->sa_handler; + ps->ps_catchmask[sig] = sa->sa_mask &~ sigcantmask; + if ((sa->sa_flags & SA_RESTART) == 0) + ps->ps_sigintr |= bit; + else + ps->ps_sigintr &= ~bit; + if (sa->sa_flags & SA_ONSTACK) + ps->ps_sigonstack |= bit; + else + ps->ps_sigonstack &= ~bit; +#ifdef COMPAT_SUNOS + if (sa->sa_flags & SA_USERTRAMP) + ps->ps_usertramp |= bit; + else + ps->ps_usertramp &= ~bit; +#endif + if (sig == SIGCHLD) { + if (sa->sa_flags & SA_NOCLDSTOP) + p->p_flag |= SNOCLDSTOP; + else + p->p_flag &= ~SNOCLDSTOP; + } + /* + * 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 (sa->sa_handler == SIG_IGN || + (sigprop[sig] & SA_IGNORE && sa->sa_handler == SIG_DFL)) { + p->p_sig &= ~bit; /* never to be seen again */ + if (sig != SIGCONT) + p->p_sigignore |= bit; /* easier in psignal */ + p->p_sigcatch &= ~bit; + } else { + p->p_sigignore &= ~bit; + if (sa->sa_handler == SIG_DFL) + p->p_sigcatch &= ~bit; + else + p->p_sigcatch |= bit; + } + (void) spl0(); } -sigpause() +/* + * Initialize signal state for process 0; + * set to ignore signals that are ignored by default. + */ +void +siginit(p) + struct proc *p; { + register int i; + for (i = 0; i < NSIG; i++) + if (sigprop[i] & SA_IGNORE && i != SIGCONT) + p->p_sigignore |= sigmask(i); } -sigstack() +/* + * Reset signals for an exec of the specified process. + */ +void +execsigs(p) + register struct proc *p; { + register struct sigacts *ps = p->p_sigacts; + register int nc, mask; + /* + * Reset caught signals. Held signals remain held + * through p_sigmask (unless they were caught, + * and are now ignored by default). + */ + while (p->p_sigcatch) { + nc = ffs((long)p->p_sigcatch); + mask = sigmask(nc); + p->p_sigcatch &= ~mask; + if (sigprop[nc] & SA_IGNORE) { + if (nc != SIGCONT) + p->p_sigignore |= mask; + p->p_sig &= ~mask; + } + ps->ps_sigact[nc] = SIG_DFL; + } + /* + * Reset stack state to the user stack. + * Clear set of signals caught on the signal stack. + */ + ps->ps_sigstk.ss_flags = SA_DISABLE; + ps->ps_sigstk.ss_size = 0; + ps->ps_sigstk.ss_base = 0; + ps->ps_flags = 0; } -kill() +/* + * Manipulate signal mask. + * Note that we receive new mask, not pointer, + * and return old mask as return value; + * the library stub does the rest. + */ +struct sigprocmask_args { + int how; + sigset_t mask; +}; +sigprocmask(p, uap, retval) + register struct proc *p; + struct sigprocmask_args *uap; + int *retval; { + int error = 0; + + *retval = p->p_sigmask; + (void) splhigh(); + switch (uap->how) { + case SIG_BLOCK: + p->p_sigmask |= uap->mask &~ sigcantmask; + break; + + case SIG_UNBLOCK: + p->p_sigmask &= ~uap->mask; + break; + + case SIG_SETMASK: + p->p_sigmask = uap->mask &~ sigcantmask; + break; + + default: + error = EINVAL; + break; + } + (void) spl0(); + return (error); } -killpg() +struct sigpending_args { + int dummy; +}; +/* ARGSUSED */ +sigpending(p, uap, retval) + struct proc *p; + struct sigpending_args *uap; + int *retval; { + *retval = p->p_sig; + return (0); } -/* BEGIN DEFUNCT */ -okill() +#if defined(COMPAT_43) || defined(COMPAT_SUNOS) +/* + * Generalized interface signal handler, 4.3-compatible. + */ +struct osigvec_args { + int signo; + struct sigvec *nsv; + struct sigvec *osv; +}; +/* ARGSUSED */ +osigvec(p, uap, retval) + struct proc *p; + register struct osigvec_args *uap; + int *retval; { - register struct proc *p; - register a, sig; - register struct a { - int pid; - int signo; - } *uap; - int f, priv; - - uap = (struct a *)u.u_ap; - f = 0; - a = uap->pid; - priv = 0; + struct sigvec vec; + register struct sigacts *ps = p->p_sigacts; + register struct sigvec *sv; + register int sig; + int bit, error; + sig = uap->signo; - if (sig < 0) - /* - * A negative signal means send to process group. - */ - uap->signo = -uap->signo; - if (uap->signo == 0 || uap->signo > NSIG) { - u.u_error = EINVAL; - return; - } - if (a > 0 && sig > 0) { - p = pfind(a); - if (p == 0 || u.u_uid && u.u_uid != p->p_uid) { - u.u_error = ESRCH; - return; - } - psignal(p, uap->signo); - return; + if (sig <= 0 || sig >= NSIG || sig == SIGKILL || sig == SIGSTOP) + return (EINVAL); + sv = &vec; + if (uap->osv) { + *(sig_t *)&sv->sv_handler = ps->ps_sigact[sig]; + sv->sv_mask = ps->ps_catchmask[sig]; + bit = sigmask(sig); + sv->sv_flags = 0; + if ((ps->ps_sigonstack & bit) != 0) + sv->sv_flags |= SV_ONSTACK; + if ((ps->ps_sigintr & bit) != 0) + sv->sv_flags |= SV_INTERRUPT; +#ifndef COMPAT_SUNOS + if (p->p_flag & SNOCLDSTOP) + sv->sv_flags |= SA_NOCLDSTOP; +#endif + if (error = copyout((caddr_t)sv, (caddr_t)uap->osv, + sizeof (vec))) + return (error); } - if (a==-1 && u.u_uid==0) { - priv++; - a = 0; - sig = -1; /* like sending to pgrp */ - } else if (a==0) { + if (uap->nsv) { + if (error = copyin((caddr_t)uap->nsv, (caddr_t)sv, + sizeof (vec))) + return (error); +#ifdef COMPAT_SUNOS /* - * Zero process id means send to my process group. + * SunOS uses this bit (4, aka SA_DISABLE) as SV_RESETHAND, + * `reset to SIG_DFL on delivery'. We have no such option + * now or ever! */ - sig = -1; - a = u.u_procp->p_pgrp; - if (a == 0) { - u.u_error = EINVAL; - return; - } - } - for(p = proc; p < procNPROC; p++) { - if (p->p_stat == NULL) - continue; - if (sig > 0) { - if (p->p_pid != a) - continue; - } else if (p->p_pgrp!=a && priv==0 || p->p_ppid==0 || - (p->p_flag&SSYS) || (priv && p==u.u_procp)) - continue; - if (u.u_uid != 0 && u.u_uid != p->p_uid && - (uap->signo != SIGCONT || !inferior(p))) - continue; - f++; - psignal(p, uap->signo); + if (sv->sv_flags & SA_DISABLE) + return (EINVAL); + sv->sv_flags |= SA_USERTRAMP; +#endif + sv->sv_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ + setsigvec(p, sig, (struct sigaction *)sv); } - if (f == 0) - u.u_error = ESRCH; + return (0); } -ossig() +struct osigblock_args { + int mask; +}; +osigblock(p, uap, retval) + register struct proc *p; + struct osigblock_args *uap; + int *retval; { - register int (*f)(); - struct a { - int signo; - int (*fun)(); - } *uap; - register struct proc *p = u.u_procp; - register a; - long sigmask; - - uap = (struct a *)u.u_ap; - a = uap->signo & SIGNUMMASK; - f = uap->fun; - if (a<=0 || a>=NSIG || a==SIGKILL || a==SIGSTOP || - a==SIGCONT && (f == SIG_IGN || f == SIG_HOLD)) { - u.u_error = EINVAL; - return; - } - if ((uap->signo &~ SIGNUMMASK) || (f != SIG_DFL && f != SIG_IGN && - SIGISDEFER(f))) - u.u_procp->p_flag |= SNUSIG; - /* - * Don't clobber registers if we are to simulate - * a ret+rti. - */ - if ((uap->signo&SIGDORTI) == 0) - u.u_r.r_val1 = (int)u.u_signal[a]; - /* - * Change setting atomically. - */ - (void) spl6(); - sigmask = 1L << (a-1); - if (u.u_signal[a] == SIG_IGN) - p->p_sig &= ~sigmask; /* never to be seen again */ - u.u_signal[a] = f; - if (f != SIG_DFL && f != SIG_IGN && f != SIG_HOLD) - f = SIG_CATCH; - if ((int)f & 1) - p->p_siga0 |= sigmask; - else - p->p_siga0 &= ~sigmask; - if ((int)f & 2) - p->p_siga1 |= sigmask; - else - p->p_siga1 &= ~sigmask; + + (void) splhigh(); + *retval = p->p_sigmask; + p->p_sigmask |= uap->mask &~ sigcantmask; + (void) spl0(); + return (0); +} + +struct osigsetmask_args { + int mask; +}; +osigsetmask(p, uap, retval) + struct proc *p; + struct osigsetmask_args *uap; + int *retval; +{ + + (void) splhigh(); + *retval = p->p_sigmask; + p->p_sigmask = uap->mask &~ sigcantmask; (void) spl0(); + 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. + */ +struct sigsuspend_args { + sigset_t mask; +}; +/* ARGSUSED */ +sigsuspend(p, uap, retval) + register struct proc *p; + struct sigsuspend_args *uap; + int *retval; +{ + register struct sigacts *ps = p->p_sigacts; + /* - * Now handle options. + * When returning from sigpause, 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. */ - if (uap->signo & SIGDOPAUSE) { - /* - * Simulate a PDP11 style wait instrution which - * atomically lowers priority, enables interrupts - * and hangs. + ps->ps_oldmask = p->p_sigmask; + ps->ps_flags |= SAS_OLDMASK; + p->p_sigmask = uap->mask &~ sigcantmask; + (void) tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0); + /* always return EINTR rather than ERESTART... */ + return (EINTR); +} + +#if defined(COMPAT_43) || defined(COMPAT_SUNOS) +struct osigstack_args { + struct sigstack *nss; + struct sigstack *oss; +}; +/* ARGSUSED */ +osigstack(p, uap, retval) + struct proc *p; + register struct osigstack_args *uap; + int *retval; +{ + struct sigstack ss; + struct sigacts *psp; + int error = 0; + + psp = p->p_sigacts; + ss.ss_sp = psp->ps_sigstk.ss_base; + ss.ss_onstack = psp->ps_sigstk.ss_flags & SA_ONSTACK; + if (uap->oss && (error = copyout((caddr_t)&ss, (caddr_t)uap->oss, + sizeof (struct sigstack)))) + return (error); + if (uap->nss && (error = copyin((caddr_t)uap->nss, (caddr_t)&ss, + sizeof (ss))) == 0) { + psp->ps_sigstk.ss_base = ss.ss_sp; + psp->ps_sigstk.ss_size = 0; + psp->ps_sigstk.ss_flags |= ss.ss_onstack & SA_ONSTACK; + psp->ps_flags |= SAS_ALTSTACK; + } + return (error); +} +#endif /* COMPAT_43 || COMPAT_SUNOS */ + +struct sigaltstack_args { + struct sigaltstack *nss; + struct sigaltstack *oss; +}; +/* ARGSUSED */ +sigaltstack(p, uap, retval) + struct proc *p; + register struct sigaltstack_args *uap; + int *retval; +{ + struct sigacts *psp; + struct sigaltstack ss; + int error; + + psp = p->p_sigacts; + if ((psp->ps_flags & SAS_ALTSTACK) == 0) + psp->ps_sigstk.ss_flags |= SA_DISABLE; + if (uap->oss && (error = copyout((caddr_t)&psp->ps_sigstk, + (caddr_t)uap->oss, sizeof (struct sigaltstack)))) + return (error); + if (uap->nss == 0) + return (0); + if (error = copyin((caddr_t)uap->nss, (caddr_t)&ss, sizeof (ss))) + return (error); + if (ss.ss_flags & SA_DISABLE) { + if (psp->ps_sigstk.ss_flags & SA_ONSTACK) + return (EINVAL); + psp->ps_flags &= ~SAS_ALTSTACK; + psp->ps_sigstk.ss_flags = ss.ss_flags; + return (0); + } + if (ss.ss_size < MINSIGSTKSZ) + return (ENOMEM); + psp->ps_flags |= SAS_ALTSTACK; + psp->ps_sigstk= ss; + return (0); +} + +struct kill_args { + int pid; + int signo; +}; +/* ARGSUSED */ +kill(cp, uap, retval) + register struct proc *cp; + register struct kill_args *uap; + int *retval; +{ + register struct proc *p; + register struct pcred *pc = cp->p_cred; + + if ((unsigned) uap->signo >= NSIG) + return (EINVAL); + if (uap->pid > 0) { + /* kill single process */ + p = pfind(uap->pid); + if (p == 0) + return (ESRCH); + if (!CANSIGNAL(cp, pc, p, uap->signo)) + return (EPERM); + if (uap->signo) + psignal(p, uap->signo); + return (0); + } + switch (uap->pid) { + case -1: /* broadcast signal */ + return (killpg1(cp, uap->signo, 0, 1)); + case 0: /* signal own process group */ + return (killpg1(cp, uap->signo, 0, 0)); + default: /* negative explicit process group */ + return (killpg1(cp, uap->signo, -uap->pid, 0)); + } + /* NOTREACHED */ +} + +#if defined(COMPAT_43) || defined(COMPAT_SUNOS) +struct okillpg_args { + int pgid; + int signo; +}; +/* ARGSUSED */ +okillpg(p, uap, retval) + struct proc *p; + register struct okillpg_args *uap; + int *retval; +{ + + if ((unsigned) uap->signo >= NSIG) + return (EINVAL); + return (killpg1(p, uap->signo, uap->pgid, 0)); +} +#endif /* COMPAT_43 || COMPAT_SUNOS */ + +/* + * Common code for kill process group/broadcast kill. + * cp is calling process. + */ +killpg1(cp, signo, pgid, all) + register struct proc *cp; + int signo, pgid, all; +{ + register struct proc *p; + register struct pcred *pc = cp->p_cred; + struct pgrp *pgrp; + int nfound = 0; + + if (all) + /* + * broadcast */ - opause(); - /*NOTREACHED*/ + for (p = (struct proc *)allproc; p != NULL; p = p->p_nxt) { + if (p->p_pid <= 1 || p->p_flag&SSYS || + p == cp || !CANSIGNAL(cp, pc, p, signo)) + continue; + nfound++; + if (signo) + psignal(p, signo); + } + else { + if (pgid == 0) + /* + * zero pgid means send to my process group. + */ + pgrp = cp->p_pgrp; + else { + pgrp = pgfind(pgid); + if (pgrp == NULL) + return (ESRCH); + } + for (p = pgrp->pg_mem; p != NULL; p = p->p_pgrpnxt) { + if (p->p_pid <= 1 || p->p_flag&SSYS || + p->p_stat == SZOMB || !CANSIGNAL(cp, pc, p, signo)) + continue; + nfound++; + if (signo) + psignal(p, signo); + } } - if (uap->signo & SIGDORTI) - u.u_eosys = SIMULATERTI; + return (nfound ? 0 : ESRCH); } /* * Send the specified signal to - * all processes with 'pgrp' as + * all processes with 'pgid' as * process group. - * Called by tty.c for quits and - * interrupts. */ -gsignal(pgrp, sig) - register int pgrp; +void +gsignal(pgid, sig) + int pgid, sig; +{ + struct pgrp *pgrp; + + if (pgid && (pgrp = pgfind(pgid))) + pgsignal(pgrp, sig, 0); +} + +/* + * Send sig to every member of 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 == 0) - return; - for(p = proc; p < procNPROC; p++) - if (p->p_pgrp == pgrp) - psignal(p, sig); + if (pgrp) + for (p = pgrp->pg_mem; p != NULL; p = p->p_pgrpnxt) + if (checkctty == 0 || p->p_flag&SCTTY) + psignal(p, sig); } /* - * Send the specified signal to - * the specified process. + * 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. + */ +void +trapsignal(p, sig, code) + struct proc *p; + register int sig; + unsigned code; +{ + register struct sigacts *ps = p->p_sigacts; + int mask; + + mask = sigmask(sig); + if ((p->p_flag & STRC) == 0 && (p->p_sigcatch & mask) != 0 && + (p->p_sigmask & mask) == 0) { + p->p_stats->p_ru.ru_nsignals++; +#ifdef KTRACE + if (KTRPOINT(p, KTR_PSIG)) + ktrpsig(p->p_tracep, sig, ps->ps_sigact[sig], + p->p_sigmask, code); +#endif + sendsig(ps->ps_sigact[sig], sig, p->p_sigmask, code); + p->p_sigmask |= ps->ps_catchmask[sig] | mask; + } else { + ps->ps_code = code; /* XXX for core dump/debugger */ + psignal(p, sig); + } +} + +/* + * Send the specified signal to the specified process. + * If the signal has an action, the action is usually performed + * by the target process rather than the caller; we simply 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 s; - register int (*action)(); - long sigmask; + register int s, prop; + register sig_t action; + int mask; - if ((unsigned)sig >= NSIG) - return; - sigmask = (1L << (sig-1)); + if ((unsigned)sig >= NSIG || sig == 0) + panic("psignal sig"); + mask = sigmask(sig); + prop = sigprop[sig]; /* * If proc is traced, always give parent a chance. - * Otherwise get the signal action from the bits in the proc table. */ if (p->p_flag & STRC) action = SIG_DFL; else { - s = (p->p_siga1&sigmask) != 0; - s <<= 1; - s |= (p->p_siga0&sigmask) != 0; - action = (int(*)())s; /* - * If the signal is ignored, we forget about it immediately. + * 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 (action == SIG_IGN) + if (p->p_sigignore & mask) return; + if (p->p_sigmask & mask) + action = SIG_HOLD; + else if (p->p_sigcatch & mask) + action = SIG_CATCH; + else + action = SIG_DFL; } -#define mask(sig) (1<<(sig-1)) -#define stops (mask(SIGSTOP)|mask(SIGTSTP)|mask(SIGTTIN)|mask(SIGTTOU)) - if (sig) { - p->p_sig |= sigmask; - switch (sig) { - - case SIGTERM: - if ((p->p_flag&STRC) != 0 || action != SIG_DFL) - break; - /* fall into ... */ - - case SIGKILL: - if (p->p_nice > NZERO) - p->p_nice = NZERO; - break; - - case SIGCONT: - p->p_sig &= ~stops; - break; - - case SIGSTOP: - case SIGTSTP: - case SIGTTIN: - case SIGTTOU: - p->p_sig &= ~mask(SIGCONT); - break; - } + + if (p->p_nice > NZERO && (sig == SIGKILL || + sig == SIGTERM && (p->p_flag&STRC || action != SIG_DFL))) + p->p_nice = NZERO; + + if (prop & SA_CONT) + p->p_sig &= ~stopsigmask; + + 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; + p->p_sig &= ~contsigmask; } -#undef mask -#undef stops + p->p_sig |= mask; + /* - * Defer further processing for signals which are held. + * Defer further processing for signals which are held, + * except that stopped processes must be continued by SIGCONT. */ - if (action == SIG_HOLD) + if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP)) return; - s = spl6(); + s = splhigh(); switch (p->p_stat) { case SSLEEP: /* - * If process is sleeping at negative priority + * 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 (p->p_pri <= PZERO) + if ((p->p_flag & SSINTR) == 0) goto out; /* * Process is sleeping and traced... make it runnable @@ -295,58 +707,29 @@ psignal(p, sig) */ if (p->p_flag&STRC) goto run; - switch (sig) { - - case SIGSTOP: - case SIGTSTP: - case SIGTTIN: - case SIGTTOU: - /* - * These are the signals which by default - * stop a process. - */ + /* + * 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 run; - /* - * Don't clog system with children of init - * stopped from the keyboard. - */ - if (sig != SIGSTOP && p->p_pptr == &proc[1]) { - psignal(p, SIGKILL); - p->p_sig &= ~sigmask; - splx(s); - return; - } + goto runfast; /* - * If a child in vfork(), stopping could - * cause deadlock. + * If a child holding parent blocked, + * stopping could cause deadlock. */ - if (p->p_flag&SVFORK) + if (p->p_flag&SPPWAIT) goto out; - p->p_sig &= ~sigmask; - p->p_cursig = sig; + p->p_sig &= ~mask; + p->p_xstat = sig; + if ((p->p_pptr->p_flag & SNOCLDSTOP) == 0) + psignal(p->p_pptr, SIGCHLD); stop(p); goto out; - - case SIGIO: - case SIGURG: - case SIGCHLD: - /* - * These signals are special in that they - * don't get propogated... if the process - * isn't interested, forget it. - */ - if (action != SIG_DFL) - goto run; - p->p_sig &= ~sigmask; /* take it away */ - goto out; - - default: - /* - * All other signals cause the process to run - */ - goto run; - } + } else + goto runfast; /*NOTREACHED*/ case SSTOP: @@ -356,50 +739,52 @@ psignal(p, sig) */ if (p->p_flag&STRC) goto out; - switch (sig) { - case SIGKILL: - /* - * Kill signal always sets processes running. - */ - goto run; + /* + * Kill signal always sets processes running. + */ + if (sig == SIGKILL) + goto runfast; - case SIGCONT: + if (prop & SA_CONT) { /* + * If SIGCONT is default (or ignored), we continue + * the process but don't leave the signal in p_sig, + * as it has no further action. If SIGCONT is held, + * continue the process and leave the signal in p_sig. * 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 || p->p_wchan == 0) + if (action == SIG_DFL) + p->p_sig &= ~mask; + if (action == SIG_CATCH) + goto runfast; + if (p->p_wchan == 0) goto run; p->p_stat = SSLEEP; goto out; + } - case SIGSTOP: - case SIGTSTP: - case SIGTTIN: - case SIGTTOU: + if (prop & SA_STOP) { /* * Already stopped, don't need to stop again. * (If we did the shell could get confused.) */ - p->p_sig &= ~sigmask; /* take it away */ - goto out; - - default: - /* - * If process is sleeping interruptibly, then - * unstick it so that when it is continued - * it can look at the signal. - * But don't setrun the process as its not to - * be unstopped by the signal alone. - */ - if (p->p_wchan && p->p_pri > PZERO) - unsleep(p); + p->p_sig &= ~mask; /* take it away */ goto out; } - /*NOTREACHED*/ + + /* + * 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 setrun the process, leave it stopped. + */ + if (p->p_wchan && p->p_flag & SSINTR) + unsleep(p); + goto out; default: /* @@ -407,170 +792,178 @@ psignal(p, sig) * other than kicking ourselves if we are running. * It will either never be noticed, or noticed very soon. */ - if (p == u.u_procp && !noproc) - aston(); + if (p == curproc) + signotify(p); goto out; } /*NOTREACHED*/ -run: + +runfast: /* * Raise priority to at least PUSER. */ if (p->p_pri > PUSER) - if ((p != u.u_procp || noproc) && p->p_stat == SRUN && - (p->p_flag & SLOAD)) { - remrq(p); - p->p_pri = PUSER; - setrq(p); - } else - p->p_pri = PUSER; + p->p_pri = PUSER; +run: setrun(p); out: splx(s); } /* - * Returns true if the current - * process has a signal to process. - * The signal to process is put in p_cursig. - * This is asked at least once each time a process enters the - * system (though this can usually be done without actually - * calling issig by checking the pending signal masks.) - * A signal does not do anything - * directly to a process; it sets - * a flag that asks the process to - * do something to itself. + * If the current process has a signal to process (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 actually calling + * issig by checking the pending signal masks in the CURSIG macro.) + * The normal call sequence is + * + * while (sig = CURSIG(curproc)) + * psig(sig); */ -issig() -{ +issig(p) register struct proc *p; - register int sig; - long sigbits; - long sigmask; +{ + register int sig, mask, prop; - p = u.u_procp; for (;;) { - sigbits = p->p_sig; - if ((p->p_flag&STRC) == 0) - sigbits &= ~p->p_ignsig; - if (p->p_flag&SVFORK) -#define bit(a) (1<<(a-1)) - sigbits &= ~(bit(SIGSTOP)|bit(SIGTSTP)|bit(SIGTTIN)|bit(SIGTTOU)); - if (sigbits == 0) - break; - sig = ffs((int)sigbits); - sigmask = 1L << (sig-1); - p->p_sig &= ~sigmask; /* take the signal! */ - p->p_cursig = sig; - if (p->p_flag&STRC && (p->p_flag&SVFORK)==0) { + mask = p->p_sig &~ p->p_sigmask; + if (p->p_flag&SPPWAIT) + mask &= ~stopsigmask; + if (mask == 0) /* no signal to send */ + return (0); + sig = ffs((long)mask); + mask = sigmask(sig); + prop = sigprop[sig]; + /* + * We should see pending but ignored signals + * only if STRC was on when they were posted. + */ + if (mask & p->p_sigignore && (p->p_flag&STRC) == 0) { + p->p_sig &= ~mask; + continue; + } + if (p->p_flag&STRC && (p->p_flag&SPPWAIT) == 0) { /* * If traced, always stop, and stay * stopped until released by the parent. */ + p->p_xstat = sig; + psignal(p->p_pptr, SIGCHLD); do { stop(p); swtch(); - } while (!procxmt() && p->p_flag&STRC); + } while (!procxmt(p) && p->p_flag&STRC); /* * If the traced bit got turned off, - * then put the signal taken above back into p_sig - * and go back up to the top to rescan signals. - * This ensures that siga0 and u_signal are consistent. + * go back up to the top to rescan signals. + * This ensures that p_sig* and ps_sigact + * are consistent. */ - if ((p->p_flag&STRC) == 0) { - p->p_sig |= sigmask; + if ((p->p_flag&STRC) == 0) continue; - } /* * If parent wants us to take the signal, - * then it will leave it in p->p_cursig; + * then it will leave it in p->p_xstat; * otherwise we just look for signals again. */ - sig = p->p_cursig; + p->p_sig &= ~mask; /* clear the old signal */ + sig = p->p_xstat; if (sig == 0) continue; + + /* + * Put the new signal into p_sig. + * If signal is being masked, + * look for other signals. + */ + mask = sigmask(sig); + p->p_sig |= mask; + if (p->p_sigmask & mask) + continue; } - switch (u.u_signal[sig]) { + + /* + * Decide whether the signal should be returned. + * Return the signal's number, or fall through + * to clear it from the pending mask. + */ + switch ((int)p->p_sigacts->ps_sigact[sig]) { case SIG_DFL: /* * Don't take default actions on system processes. */ - if (p->p_ppid == 0) - break; - switch (sig) { - - case SIGTSTP: - case SIGTTIN: - case SIGTTOU: + if (p->p_pid <= 1) { +#ifdef DIAGNOSTIC /* - * Children of init aren't allowed to stop - * on signals from the keyboard. + * Are you sure you want to ignore SIGSEGV + * in init? XXX */ - if (p->p_pptr == &proc[1]) { - psignal(p, SIGKILL); - continue; - } - /* fall into ... */ - - case SIGSTOP: - if (p->p_flag&STRC) - continue; + printf("Process (pid %d) got signal %d\n", + 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&STRC || + (p->p_pgrp->pg_jobc == 0 && + prop & SA_TTYSTOP)) + break; /* == ignore */ + p->p_xstat = sig; stop(p); + if ((p->p_pptr->p_flag & SNOCLDSTOP) == 0) + psignal(p->p_pptr, SIGCHLD); swtch(); - continue; - - case SIGCONT: - case SIGCHLD: + break; + } else if (prop & SA_IGNORE) { /* - * These signals are normally not - * sent if the action is the default. + * Except for SIGCONT, shouldn't get here. + * Default action is to ignore; drop it. */ - continue; /* == ignore */ - - default: - goto send; - } + break; /* == ignore */ + } else + return (sig); /*NOTREACHED*/ - case SIG_HOLD: case SIG_IGN: /* - * Masking above should prevent us - * ever trying to take action on a held - * or ignored signal, unless process is traced. + * Masking above should prevent us ever trying + * to take action on an ignored signal other + * than SIGCONT, unless process is traced. */ - if ((p->p_flag&STRC) == 0) + if ((prop & SA_CONT) == 0 && (p->p_flag&STRC) == 0) printf("issig\n"); - continue; + break; /* == ignore */ default: /* * This signal has an action, let * psig process it. */ - goto send; + return (sig); } - /*NOTREACHED*/ + p->p_sig &= ~mask; /* take the signal! */ } - /* - * Didn't find a signal to send. - */ - p->p_cursig = 0; - return (0); - -send: - /* - * Let psig process the signal. - */ - return (sig); + /* NOTREACHED */ } /* * Put the argument process into the stopped - * state and notify the parent via wakeup and/or signal. + * state and notify the parent via wakeup. + * Signals are handled elsewhere. + * The process must not be on the run queue. */ stop(p) register struct proc *p; @@ -579,175 +972,167 @@ stop(p) p->p_stat = SSTOP; p->p_flag &= ~SWTED; wakeup((caddr_t)p->p_pptr); - /* - * Avoid sending signal to parent if process is traced - */ - if (p->p_flag&STRC) - return; - psignal(p->p_pptr, SIGCHLD); } /* - * Perform the action specified by - * the current signal. - * The usual sequence is: - * if (issig()) - * psig(); - * The signal bit has already been cleared by issig, - * and the current signal number stored in p->p_cursig. + * Take the action for the specified signal + * from the current set of pending signals. */ -psig() +void +psig(sig) + register int sig; { - register struct proc *rp = u.u_procp; - register int n = rp->p_cursig; - long sigmask = 1L << (n-1); - register int (*action)(); + register struct proc *p = curproc; + register struct sigacts *ps = p->p_sigacts; + register sig_t action; + int mask, returnmask; - if (rp->p_cursig == 0) +#ifdef DIAGNOSTIC + if (sig == 0) panic("psig"); - action = u.u_signal[n]; - if (action != SIG_DFL) { - if (action == SIG_IGN || action == SIG_HOLD) +#endif + mask = sigmask(sig); + p->p_sig &= ~mask; + action = ps->ps_sigact[sig]; +#ifdef KTRACE + if (KTRPOINT(p, KTR_PSIG)) + ktrpsig(p->p_tracep, sig, action, ps->ps_flags & SAS_OLDMASK ? + ps->ps_oldmask : p->p_sigmask, 0); +#endif + if (action == SIG_DFL) { + /* + * Default action, where the default is to kill + * the process. (Other cases were ignored above.) + */ + sigexit(p, sig); + /* NOTREACHED */ + } else { + /* + * If we get here, the signal must be caught. + */ +#ifdef DIAGNOSTIC + if (action == SIG_IGN || (p->p_sigmask & mask)) panic("psig action"); - u.u_error = 0; - if (n != SIGILL && n != SIGTRAP) - u.u_signal[n] = 0; +#endif /* - * If this catch value indicates automatic holding of - * subsequent signals, set the hold value. + * Set the new mask value and also defer further + * occurences of this signal. + * + * Special case: user has done a sigpause. Here the + * current mask is not of interest, but rather the + * mask from before the sigpause is what we want + * restored after the signal processing is completed. */ - if (SIGISDEFER(action)) { - (void) spl6(); - if ((int)SIG_HOLD & 1) - rp->p_siga0 |= sigmask; - else - rp->p_siga0 &= ~sigmask; - if ((int)SIG_HOLD & 2) - rp->p_siga1 |= sigmask; - else - rp->p_siga1 &= ~sigmask; - u.u_signal[n] = SIG_HOLD; - (void) spl0(); - action = SIGUNDEFER(action); - } - u.u_ru.ru_nsignals++; - sendsig(action, n); - rp->p_cursig = 0; - return; - } - u.u_acflag |= AXSIG; - switch (n) { - - case SIGILL: - case SIGIOT: - case SIGBUS: - case SIGQUIT: - case SIGTRAP: - case SIGEMT: - case SIGFPE: - case SIGSEGV: - case SIGSYS: - u.u_arg[0] = n; - if (core()) - n += 0200; + (void) splhigh(); + if (ps->ps_flags & SAS_OLDMASK) { + returnmask = ps->ps_oldmask; + ps->ps_flags &= ~SAS_OLDMASK; + } else + returnmask = p->p_sigmask; + p->p_sigmask |= ps->ps_catchmask[sig] | mask; + (void) spl0(); + p->p_stats->p_ru.ru_nsignals++; + sendsig(action, sig, returnmask, 0); } - exit(n); } -#ifdef unneeded -int corestop = 0; -#endif /* - * Create a core image on the file "core" - * If you are looking for protection glitches, - * there are probably a wealth of them here - * when this occurs to a suid command. - * - * It writes UPAGES block of the - * user.h area followed by the entire - * data+stack segments. + * 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. */ -core() +sigexit(p, sig) + register struct proc *p; + int sig; { - register struct inode *ip; - extern schar(); - -#ifdef unneeded - if (corestop) { - int i; - for (i = 0; i < 10; i++) - if (u.u_comm[i]) - putchar(u.u_comm[i], 0); - printf(", uid %d\n", u.u_uid); - if (corestop&2) - asm("halt"); - } -#endif - if (u.u_uid != u.u_ruid) - return (0); - if (ctob(UPAGES+u.u_dsize+u.u_ssize) >= - u.u_rlimit[RLIMIT_CORE].rlim_cur) - return (0); - u.u_error = 0; - u.u_dirp = "core"; - ip = namei(schar, 1, 1); - if (ip == NULL) { - if (u.u_error) - return (0); - ip = maknode(0666); - if (ip==NULL) - return (0); - } - if (access(ip, IWRITE) || - (ip->i_mode&IFMT) != IFREG || - ip->i_nlink != 1) { - u.u_error = EFAULT; - goto out; + + p->p_acflag |= AXSIG; + if (sigprop[sig] & SA_CORE) { + p->p_sigacts->ps_sig = sig; + if (coredump(p) == 0) + sig |= WCOREFLAG; } - itrunc(ip, 0); - u.u_acflag |= ACORE; - u.u_error =rdwri(UIO_WRITE, ip, - (caddr_t)&u, ctob(UPAGES), - 0, 1, (int *)0); - if (u.u_error) - rdwri(UIO_WRITE, ip, - (caddr_t)ctob(u.u_tsize), ctob(u.u_dsize), - ctob(UPAGES), 0, (int *)0); - if (u.u_error) - rdwri(UIO_WRITE, ip, - (caddr_t)(USRSTACK-ctob(u.u_ssize)), ctob(u.u_ssize), - ctob(UPAGES)+ctob(u.u_dsize), 0, (int *)0); -out: - iput(ip); - return (u.u_error == 0); + exit(p, W_EXITCODE(0, sig)); + /* NOTREACHED */ } /* - * alarm clock signal + * Create a core dump. + * The file name is "core.progname". + * Core dumps are not created if the process is setuid. */ -oalarm() +coredump(p) + register struct proc *p; { - register struct a { - int deltat; - } *uap = (struct a *)u.u_ap; - register struct proc *p = u.u_procp; - int s = spl7(); - - p->p_realtimer.itimer_reload = 0; - u.u_r.r_val1 = p->p_realtimer.itimer_value.tv_sec; - p->p_realtimer.itimer_value.tv_sec = uap->deltat; - p->p_realtimer.itimer_value.tv_usec = 0; - splx(s); + register struct vnode *vp; + register struct pcred *pcred = p->p_cred; + register struct ucred *cred = pcred->pc_ucred; + register struct vmspace *vm = p->p_vmspace; + struct vattr vattr; + int error, error1; + struct nameidata nd; + char name[MAXCOMLEN+6]; /* core.progname */ + + if (pcred->p_svuid != pcred->p_ruid || + pcred->p_svgid != pcred->p_rgid) + return (EFAULT); + if (ctob(UPAGES + vm->vm_dsize + vm->vm_ssize) >= + p->p_rlimit[RLIMIT_CORE].rlim_cur) + return (EFAULT); + sprintf(name, "core.%s", p->p_comm); + NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, name, p); + if (error = vn_open(&nd, O_CREAT|FWRITE, 0644)) + return (error); + vp = nd.ni_vp; + if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred, p) || + vattr.va_nlink != 1) { + error = EFAULT; + goto out; + } + VATTR_NULL(&vattr); + vattr.va_size = 0; + LEASE_CHECK(vp, p, cred, LEASE_WRITE); + VOP_SETATTR(vp, &vattr, cred, p); + p->p_acflag |= ACORE; + bcopy(p, &p->p_addr->u_kproc.kp_proc, sizeof(struct proc)); + fill_eproc(p, &p->p_addr->u_kproc.kp_eproc); + error = cpu_coredump(p, vp, cred); + if (error == 0) + error = vn_rdwr(UIO_WRITE, vp, vm->vm_daddr, + (int)ctob(vm->vm_dsize), (off_t)ctob(UPAGES), UIO_USERSPACE, + IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p); + if (error == 0) + error = vn_rdwr(UIO_WRITE, vp, + (caddr_t) trunc_page(USRSTACK - ctob(vm->vm_ssize)), + round_page(ctob(vm->vm_ssize)), + (off_t)ctob(UPAGES) + ctob(vm->vm_dsize), UIO_USERSPACE, + IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p); +out: + VOP_UNLOCK(vp); + error1 = vn_close(vp, FWRITE, cred, p); + if (error == 0) + error = error1; + return (error); } /* - * indefinite wait. - * no one should wakeup(&u) + * Nonexistent system call-- signal process (may want to handle it). + * Flag error in case process won't see signal immediately (blocked or ignored). */ -opause() +struct nosys_args { + int dummy; +}; +/* ARGSUSED */ +nosys(p, args, retval) + struct proc *p; + struct nosys_args *args; + int *retval; { - for (;;) - sleep((caddr_t)&u, PSLEP); + psignal(p, SIGSYS); + return (EINVAL); } -