X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/206ecc7290503ee29a05ab0340b54f3e67803ba9..d9c2f47f02d3238dc46704445f1f6dc0a68fa6f0:/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 00600af22e..6cf7c642af 100644 --- a/usr/src/sys/kern/kern_sig.c +++ b/usr/src/sys/kern/kern_sig.c @@ -1,292 +1,620 @@ -/* kern_sig.c 5.8 82/10/10 */ - -#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/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" -#include "../h/kernel.h" - -/* KILL CODE SHOULDNT KNOW ABOUT PROCESS INTERNALS !?! */ - -sigvec() +/* + * Copyright (c) 1982, 1986, 1989 Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + * @(#)kern_sig.c 7.22 (Berkeley) %G% + */ + +#include "param.h" +#include "systm.h" +#include "user.h" +#include "vnode.h" +#include "proc.h" +#include "timeb.h" +#include "times.h" +#include "buf.h" +#include "text.h" +#include "seg.h" +#include "vm.h" +#include "acct.h" +#include "uio.h" +#include "file.h" +#include "kernel.h" +#include "wait.h" +#include "ktrace.h" + +#include "machine/reg.h" +#include "machine/pte.h" +#include "machine/psl.h" +#include "machine/mtpr.h" + +#define ttystopsigmask (sigmask(SIGTSTP)|sigmask(SIGTTIN)|sigmask(SIGTTOU)) +#define stopsigmask (sigmask(SIGSTOP)|ttystopsigmask) +#define defaultignmask (sigmask(SIGCONT)|sigmask(SIGIO)|sigmask(SIGURG)| \ + sigmask(SIGCHLD)|sigmask(SIGWINCH)|sigmask(SIGINFO)) + +/* + * Can process p send the signal signo to process q? + */ +#define CANSIGNAL(p, q, signo) \ + ((p)->p_uid == 0 || \ + (p)->p_ruid == (q)->p_ruid || (p)->p_uid == (q)->p_ruid || \ + (p)->p_ruid == (q)->p_uid || (p)->p_uid == (q)->p_uid || \ + ((signo) == SIGCONT && (q)->p_session == (p)->p_session)) + +/* ARGSUSED */ +sigaction(p, uap, retval) + struct proc *p; + register struct args { + int signo; + struct sigaction *nsa; + struct sigaction *osa; + } *uap; + int *retval; { + struct sigaction vec; + register struct sigaction *sa; + 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 = u.u_signal[sig]; + sa->sa_mask = u.u_sigmask[sig]; + bit = sigmask(sig); + sa->sa_flags = 0; + if ((u.u_sigonstack & bit) != 0) + sa->sa_flags |= SA_ONSTACK; + if ((u.u_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); } -sigblock() +setsigvec(p, sig, sa) + register struct proc *p; + int sig; + register struct sigaction *sa; { + register int bit; + bit = sigmask(sig); + /* + * Change setting atomically. + */ + (void) splhigh(); + u.u_signal[sig] = sa->sa_handler; + u.u_sigmask[sig] = sa->sa_mask &~ sigcantmask; + if ((sa->sa_flags & SA_RESTART) == 0) + u.u_sigintr |= bit; + else + u.u_sigintr &= ~bit; + if (sa->sa_flags & SA_ONSTACK) + u.u_sigonstack |= bit; + else + u.u_sigonstack &= ~bit; + 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 || + (bit & defaultignmask && 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(); } -sigsetmask() +/* + * Initialize signal state for process 0; + * set to ignore signals that are ignored by default. + */ +siginit(p) + struct proc *p; { + p->p_sigignore = defaultignmask &~ sigmask(SIGCONT); } -sigpause() +/* + * Reset signals for an exec of the specified process. + */ +execsigs(p) + register struct proc *p; { + 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 (mask & defaultignmask) { + if (nc != SIGCONT) + p->p_sigignore |= mask; + p->p_sig &= ~mask; + } + u.u_signal[nc] = SIG_DFL; + } + /* + * Reset stack state to the user stack. + * Clear set of signals caught on the signal stack. + */ + u.u_onstack = 0; + u.u_sigsp = 0; + u.u_sigonstack = 0; } -sigstack() +/* + * Manipulate signal mask. + * Note that we receive new mask, not pointer, + * and return old mask as return value; + * the library stub does the rest. + */ +sigprocmask(p, uap, retval) + register struct proc *p; + struct args { + int how; + sigset_t mask; + } *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); } -kill() +/* ARGSUSED */ +sigpending(p, uap, retval) + struct proc *p; + void *uap; + int *retval; { + *retval = p->p_sig; + return (0); } -killpg() +#ifdef COMPAT_43 +/* + * Generalized interface signal handler, 4.3-compatible. + */ +/* ARGSUSED */ +osigvec(p, uap, retval) + struct proc *p; + register struct args { + int signo; + struct sigvec *nsv; + struct sigvec *osv; + } *uap; + int *retval; { + struct sigvec vec; + register struct sigvec *sv; + register int sig; + int bit, error; + sig = uap->signo; + if (sig <= 0 || sig >= NSIG || sig == SIGKILL || sig == SIGSTOP) + return (EINVAL); + sv = &vec; + if (uap->osv) { + *(sig_t *)&sv->sv_handler = u.u_signal[sig]; + sv->sv_mask = u.u_sigmask[sig]; + bit = sigmask(sig); + sv->sv_flags = 0; + if ((u.u_sigonstack & bit) != 0) + sv->sv_flags |= SV_ONSTACK; + if ((u.u_sigintr & bit) != 0) + sv->sv_flags |= SV_INTERRUPT; + if (p->p_flag & SNOCLDSTOP) + sv->sv_flags |= SA_NOCLDSTOP; + if (error = copyout((caddr_t)sv, (caddr_t)uap->osv, + sizeof (vec))) + return (error); + } + if (uap->nsv) { + if (error = copyin((caddr_t)uap->nsv, (caddr_t)sv, + sizeof (vec))) + return (error); + sv->sv_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ + setsigvec(p, sig, (struct sigaction *)sv); + } + return (0); } -/* BEGIN DEFUNCT */ -okill() +osigblock(p, uap, retval) + register struct proc *p; + struct args { + int mask; + } *uap; + int *retval; { + + (void) splhigh(); + *retval = p->p_sigmask; + p->p_sigmask |= uap->mask &~ sigcantmask; + (void) spl0(); + return (0); +} + +osigsetmask(p, uap, retval) + struct proc *p; + struct args { + int mask; + } *uap; + int *retval; +{ + + (void) splhigh(); + *retval = p->p_sigmask; + p->p_sigmask = uap->mask &~ sigcantmask; + (void) spl0(); + return (0); +} +#endif + +/* + * 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. + */ +/* ARGSUSED */ +sigsuspend(p, uap, retval) register struct proc *p; - register a, sig; - register struct a { + struct args { + sigset_t mask; + } *uap; + int *retval; +{ + + /* + * 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 proc structure + * to indicate this (should be in u.). + */ + u.u_oldmask = p->p_sigmask; + p->p_flag |= SOMASK; + p->p_sigmask = uap->mask &~ sigcantmask; + (void) tsleep((caddr_t)&u, PPAUSE | PCATCH, "pause", 0); + /* always return EINTR rather than ERESTART... */ + return (EINTR); +} + +/* ARGSUSED */ +sigstack(p, uap, retval) + struct proc *p; + register struct args { + struct sigstack *nss; + struct sigstack *oss; + } *uap; + int *retval; +{ + struct sigstack ss; + int error = 0; + + if (uap->oss && (error = copyout((caddr_t)&u.u_sigstack, + (caddr_t)uap->oss, sizeof (struct sigstack)))) + return (error); + if (uap->nss && (error = copyin((caddr_t)uap->nss, (caddr_t)&ss, + sizeof (ss))) == 0) + u.u_sigstack = ss; + return (error); +} + +/* ARGSUSED */ +kill(cp, uap, retval) + register struct proc *cp; + register struct args { int pid; int signo; } *uap; - int f, priv; + int *retval; +{ + register struct proc *p; - uap = (struct a *)u.u_ap; - f = 0; - a = uap->pid; - priv = 0; - 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 ((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, p, uap->signo)) + return (EPERM); + if (uap->signo) + psignal(p, uap->signo); + return (0); } - if (a==-1 && u.u_uid==0) { - priv++; - a = 0; - sig = -1; /* like sending to pgrp */ - } else if (a==0) { - /* - * Zero process id means send to my process group. - */ - sig = -1; - a = u.u_procp->p_pgrp; - if (a == 0) { - u.u_error = EINVAL; - return; - } + 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)); } - 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 (f == 0) - u.u_error = ESRCH; + /* NOTREACHED */ } -ossig() -{ - register int (*f)(); - struct a { +#ifdef COMPAT_43 +/* ARGSUSED */ +okillpg(p, uap, retval) + struct proc *p; + register struct args { + int pgid; 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) spl0(); - /* - * Now handle options. - */ - if (uap->signo & SIGDOPAUSE) { - /* - * Simulate a PDP11 style wait instrution which - * atomically lowers priority, enables interrupts - * and hangs. + int *retval; +{ + + if ((unsigned) uap->signo >= NSIG) + return (EINVAL); + return (killpg1(p, uap->signo, uap->pgid, 0)); +} +#endif + +/* + * 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; + struct pgrp *pgrp; + int f = 0; + + if (all) + /* + * broadcast */ - opause(); - /*NOTREACHED*/ + for (p = allproc; p != NULL; p = p->p_nxt) { + if (p->p_ppid == 0 || p->p_flag&SSYS || + p == u.u_procp || !CANSIGNAL(cp, p, signo)) + continue; + f++; + if (signo) + psignal(p, signo); + } + else { + if (pgid == 0) + /* + * zero pgid means send to my process group. + */ + pgrp = u.u_procp->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_ppid == 0 || p->p_flag&SSYS || + !CANSIGNAL(cp, p, signo)) + continue; + f++; + if (signo) + psignal(p, signo); + } } - if (uap->signo & SIGDORTI) - u.u_eosys = SIMULATERTI; + return (f ? 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; +gsignal(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. + */ +pgsignal(pgrp, sig, checkctty) + struct pgrp *pgrp; { 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. + */ +trapsignal(sig, code) + register int sig; + unsigned code; +{ + register struct proc *p = u.u_procp; /* XXX */ + int mask; + + mask = sigmask(sig); + if ((p->p_flag & STRC) == 0 && (p->p_sigcatch & mask) != 0 && + (p->p_sigmask & mask) == 0) { + u.u_ru.ru_nsignals++; +#ifdef KTRACE + if (KTRPOINT(p, KTR_PSIG)) + ktrpsig(p->p_tracep, sig, u.u_signal[sig], + p->p_sigmask, code); +#endif + sendsig(u.u_signal[sig], sig, p->p_sigmask, code); + p->p_sigmask |= u.u_sigmask[sig] | mask; + } else { + u.u_code = code; /* XXX for core dump/debugger */ + psignal(p, sig); + } +} + +/* + * Send the specified signal to the specified process. + * Most signals do not do anything directly to a process; + * they set a flag that asks the process to do something to itself. + * 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. */ psignal(p, sig) register struct proc *p; register int sig; { register int s; - register int (*action)(); - long sigmask; + 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); /* * 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) { + 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; + case SIGTERM: + if ((p->p_flag&STRC) || action != SIG_DFL) break; + /* FALLTHROUGH */ - case SIGCONT: - p->p_sig &= ~stops; - break; + case SIGKILL: + if (p->p_nice > NZERO) + p->p_nice = NZERO; + break; - case SIGSTOP: - case SIGTSTP: - case SIGTTIN: - case SIGTTOU: - p->p_sig &= ~mask(SIGCONT); - break; - } + case SIGCONT: + p->p_sig &= ~stopsigmask; + break; + + case SIGTSTP: + case SIGTTIN: + case SIGTTOU: + case SIGSTOP: + p->p_sig &= ~sigmask(SIGCONT); + break; } -#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 && (sig != SIGCONT || 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 +623,29 @@ 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 (mask & stopsigmask) { 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 (p->p_flag&SVFORK) 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: @@ -362,16 +661,24 @@ psignal(p, sig) /* * Kill signal always sets processes running. */ - goto run; + goto runfast; case SIGCONT: /* + * 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; @@ -384,18 +691,17 @@ psignal(p, sig) * Already stopped, don't need to stop again. * (If we did the shell could get confused.) */ - p->p_sig &= ~sigmask; /* take it away */ + p->p_sig &= ~mask; /* 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. + * 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_pri > PZERO) + if (p->p_wchan && p->p_flag & SSINTR) unsleep(p); goto out; } @@ -408,170 +714,162 @@ psignal(p, sig) * It will either never be noticed, or noticed very soon. */ if (p == u.u_procp && !noproc) -#include "../vax/mtpr.h" aston(); 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. + * 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 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. */ issig() { - register struct proc *p; - register int sig; - long sigbits; - long sigmask; + register struct proc *p = u.u_procp; /* XXX */ + register int sig, mask; - p = u.u_procp; for (;;) { - sigbits = p->p_sig; - if ((p->p_flag&STRC) == 0) - sigbits &= ~p->p_ignsig; + mask = p->p_sig &~ p->p_sigmask; 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 &= ~stopsigmask; + if (mask == 0) /* no signal to send */ + return (0); + sig = ffs((long)mask); + mask = sigmask(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&SVFORK) == 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 u_signal 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)u.u_signal[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: - /* - * Children of init aren't allowed to stop - * on signals from the keyboard. - */ - if (p->p_pptr == &proc[1]) { - psignal(p, SIGKILL); - continue; - } - /* fall into ... */ - - case SIGSTOP: - if (p->p_flag&STRC) - continue; + 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 (mask & stopsigmask) { + if (p->p_flag&STRC || + (p->p_pgrp->pg_jobc == 0 && + mask & ttystopsigmask)) + 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 (mask & defaultignmask) { /* - * 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 (sig != SIGCONT && (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; @@ -580,145 +878,167 @@ 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. + * 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. + * if (sig = CURSIG(p)) + * psig(sig); */ -psig() +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)(); - - if (rp->p_cursig == 0) - panic("psig"); - action = u.u_signal[n]; - if (action != SIG_DFL) { - if (action == SIG_IGN || action == SIG_HOLD) - panic("psig action"); - u.u_error = 0; - if (n != SIGILL && n != SIGTRAP) - u.u_signal[n] = 0; - /* - * If this catch value indicates automatic holding of - * subsequent signals, set the hold value. - */ - 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; + register struct proc *p = u.u_procp; + int mask, returnmask; + register sig_t action; + + do { +#ifdef DIAGNOSTIC + if (sig == 0) + panic("psig"); +#endif + mask = sigmask(sig); + p->p_sig &= ~mask; + action = u.u_signal[sig]; +#ifdef KTRACE + if (KTRPOINT(p, KTR_PSIG)) + ktrpsig(p->p_tracep, sig, action, p->p_flag & SOMASK ? + u.u_oldmask : p->p_sigmask, 0); +#endif + if (action != SIG_DFL) { +#ifdef DIAGNOSTIC + if (action == SIG_IGN || (p->p_sigmask & mask)) + panic("psig action"); +#endif + /* + * 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. + */ + (void) splhigh(); + if (p->p_flag & SOMASK) { + returnmask = u.u_oldmask; + p->p_flag &= ~SOMASK; + } else + returnmask = p->p_sigmask; + p->p_sigmask |= u.u_sigmask[sig] | mask; (void) spl0(); - action = SIGUNDEFER(action); + u.u_ru.ru_nsignals++; + sendsig(action, sig, returnmask, 0); + continue; } - 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; - } - exit(n); + u.u_acflag |= AXSIG; + switch (sig) { + + case SIGILL: + case SIGIOT: + case SIGBUS: + case SIGQUIT: + case SIGTRAP: + case SIGEMT: + case SIGFPE: + case SIGSEGV: + case SIGSYS: + u.u_sig = sig; + if (core() == 0) + sig |= WCOREFLAG; + } + exit(p, W_EXITCODE(0, sig)); + /* NOTREACHED */ + } while (sig = CURSIG(p)); } -#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. - * + * Create a core image on the file "core". * It writes UPAGES block of the * user.h area followed by the entire * data+stack segments. */ core() { - 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) >= + register struct vnode *vp; + register struct proc *p = u.u_procp; + register struct nameidata *ndp = &u.u_nd; + struct vattr vattr; + int error; + + if (p->p_svuid != p->p_ruid || p->p_svgid != p->p_rgid) + return (EFAULT); + 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); + return (EFAULT); + if (p->p_textp) { + VOP_LOCK(p->p_textp->x_vptr); + error = VOP_ACCESS(p->p_textp->x_vptr, VREAD, u.u_cred); + VOP_UNLOCK(p->p_textp->x_vptr); + if (error) + return (EFAULT); } - if (access(ip, IWRITE) || - (ip->i_mode&IFMT) != IFREG || - ip->i_nlink != 1) { - u.u_error = EFAULT; - goto out; + ndp->ni_segflg = UIO_SYSSPACE; + ndp->ni_dirp = "core"; + if (error = vn_open(ndp, FCREAT|FWRITE, 0644)) + return (error); + vp = ndp->ni_vp; + VOP_LOCK(vp); + if (vp->v_type != VREG || + VOP_GETATTR(vp, &vattr, u.u_cred) || + vattr.va_nlink != 1) { + vput(vp); + return (EFAULT); + } +#ifdef MAPMEM + if (error = mmcore(p)) { + vput(vp); + return (error); } - itrunc(ip, 0); +#endif + VATTR_NULL(&vattr); + vattr.va_size = 0; + VOP_SETATTR(vp, &vattr, u.u_cred); u.u_acflag |= ACORE; - u.u_error =rdwri(UIO_WRITE, ip, - (caddr_t)&u, ctob(UPAGES), - 0, 1, (int *)0); - if (u.u_error == 0) - rdwri(UIO_WRITE, ip, - (caddr_t)ctob(u.u_tsize), ctob(u.u_dsize), - ctob(UPAGES), 0, (int *)0); - if (u.u_error == 0) - 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); +#ifdef HPUXCOMPAT + /* + * BLETCH! If we loaded from an HPUX format binary file + * we have to dump an HPUX style user struct so that the + * HPUX debuggers can grok it. + */ + if (u.u_pcb.pcb_flags & PCB_HPUXBIN) + error = hpuxdumpu(vp, ndp->ni_cred); + else +#endif + error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&u, ctob(UPAGES), (off_t)0, + UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, ndp->ni_cred, (int *)0); + if (error == 0) + error = vn_rdwr(UIO_WRITE, vp, + (caddr_t)ctob(dptov(p, 0)), + (int)ctob(u.u_dsize), (off_t)ctob(UPAGES), UIO_USERSPACE, + IO_NODELOCKED|IO_UNIT, ndp->ni_cred, (int *)0); + if (error == 0) + error = vn_rdwr(UIO_WRITE, vp, + (caddr_t)ctob(sptov(p, u.u_ssize - 1)), + (int)ctob(u.u_ssize), + (off_t)ctob(UPAGES) + ctob(u.u_dsize), UIO_USERSPACE, + IO_NODELOCKED|IO_UNIT, ndp->ni_cred, (int *)0); + vput(vp); + 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). + */ +/* ARGSUSED */ +nosys(p, args, retval) + struct proc *p; + void *args; + int *retval; +{ + + psignal(p, SIGSYS); + return (EINVAL); }