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NetBSD/sys/kern/kern_sig.c
cgd 8595fc3073 make coredump() use more sensible error returns (even though they're 
not used by anything, for now), and implement MNT_NOCOREDUMP by checking
whether or not MNT_NOCOREDUMP is set on the file system where the dump
would land (i.e. the file system of the process's current working
directory), and disallowing the core dump if it's set.
1996-10-23 23:13:19 +00:00

1167 lines
29 KiB
C
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/* $NetBSD: kern_sig.c,v 1.59 1996/10/23 23:13:19 cgd Exp $ */
/*
* 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
*/
#define SIGPROP /* include signal properties table */
#include <sys/param.h>
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/timeb.h>
#include <sys/times.h>
#include <sys/buf.h>
#include <sys/acct.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/wait.h>
#include <sys/ktrace.h>
#include <sys/syslog.h>
#include <sys/stat.h>
#include <sys/core.h>
#include <sys/ptrace.h>
#include <sys/filedesc.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <machine/cpu.h>
#include <vm/vm.h>
#include <sys/user.h> /* for coredump */
void stop __P((struct proc *p));
void killproc __P((struct proc *, char *));
/*
* Can process p, with pcred pc, send the signal signum to process q?
*/
#define CANSIGNAL(p, pc, q, signum) \
((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 || \
((signum) == SIGCONT && (q)->p_session == (p)->p_session))
/* ARGSUSED */
int
sys_sigaction(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
register struct sys_sigaction_args /* {
syscallarg(int) signum;
syscallarg(struct sigaction *) nsa;
syscallarg(struct sigaction *) osa;
} */ *uap = v;
struct sigaction vec;
register struct sigaction *sa;
register struct sigacts *ps = p->p_sigacts;
register int signum;
int bit, error;
signum = SCARG(uap, signum);
if (signum <= 0 || signum >= NSIG ||
signum == SIGKILL || signum == SIGSTOP)
return (EINVAL);
sa = &vec;
if (SCARG(uap, osa)) {
sa->sa_handler = ps->ps_sigact[signum];
sa->sa_mask = ps->ps_catchmask[signum];
bit = sigmask(signum);
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 ((ps->ps_sigreset & bit) != 0)
sa->sa_flags |= SA_RESETHAND;
if (signum == SIGCHLD) {
if ((p->p_flag & P_NOCLDSTOP) != 0)
sa->sa_flags |= SA_NOCLDSTOP;
}
if ((sa->sa_mask & bit) == 0)
sa->sa_flags |= SA_NODEFER;
sa->sa_mask &= ~bit;
error = copyout((caddr_t)sa, (caddr_t)SCARG(uap, osa),
sizeof (vec));
if (error)
return (error);
}
if (SCARG(uap, nsa)) {
error = copyin((caddr_t)SCARG(uap, nsa), (caddr_t)sa,
sizeof (vec));
if (error)
return (error);
setsigvec(p, signum, sa);
}
return (0);
}
void
setsigvec(p, signum, sa)
register struct proc *p;
int signum;
register struct sigaction *sa;
{
register struct sigacts *ps = p->p_sigacts;
register int bit;
bit = sigmask(signum);
/*
* Change setting atomically.
*/
(void) splhigh();
ps->ps_sigact[signum] = sa->sa_handler;
if ((sa->sa_flags & SA_NODEFER) == 0)
sa->sa_mask |= sigmask(signum);
ps->ps_catchmask[signum] = sa->sa_mask &~ sigcantmask;
if (signum == SIGCHLD) {
if (sa->sa_flags & SA_NOCLDSTOP)
p->p_flag |= P_NOCLDSTOP;
else
p->p_flag &= ~P_NOCLDSTOP;
}
if ((sa->sa_flags & SA_RESETHAND) != 0)
ps->ps_sigreset |= bit;
else
ps->ps_sigreset &= ~bit;
if ((sa->sa_flags & SA_RESTART) == 0)
ps->ps_sigintr |= bit;
else
ps->ps_sigintr &= ~bit;
if ((sa->sa_flags & SA_ONSTACK) != 0)
ps->ps_sigonstack |= bit;
else
ps->ps_sigonstack &= ~bit;
#ifdef COMPAT_SUNOS
{
extern struct emul emul_sunos;
if (p->p_emul == &emul_sunos && sa->sa_flags & SA_USERTRAMP)
ps->ps_usertramp |= bit;
else
ps->ps_usertramp &= ~bit;
}
#endif
/*
* 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[signum] & SA_IGNORE && sa->sa_handler == SIG_DFL)) {
p->p_siglist &= ~bit; /* never to be seen again */
if (signum != 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();
}
/*
* 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);
}
/*
* 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_siglist &= ~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 = SS_DISABLE;
ps->ps_sigstk.ss_size = 0;
ps->ps_sigstk.ss_sp = 0;
ps->ps_flags = 0;
}
/*
* Manipulate signal mask.
* Note that we receive new mask, not pointer,
* and return old mask as return value;
* the library stub does the rest.
*/
int
sys_sigprocmask(p, v, retval)
register struct proc *p;
void *v;
register_t *retval;
{
struct sys_sigprocmask_args /* {
syscallarg(int) how;
syscallarg(sigset_t) mask;
} */ *uap = v;
int error = 0;
*retval = p->p_sigmask;
(void) splhigh();
switch (SCARG(uap, how)) {
case SIG_BLOCK:
p->p_sigmask |= SCARG(uap, mask) &~ sigcantmask;
break;
case SIG_UNBLOCK:
p->p_sigmask &= ~SCARG(uap, mask);
break;
case SIG_SETMASK:
p->p_sigmask = SCARG(uap, mask) &~ sigcantmask;
break;
default:
error = EINVAL;
break;
}
(void) spl0();
return (error);
}
/* ARGSUSED */
int
sys_sigpending(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
*retval = p->p_siglist;
return (0);
}
/*
* 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 */
int
sys_sigsuspend(p, v, retval)
register struct proc *p;
void *v;
register_t *retval;
{
struct sys_sigsuspend_args /* {
syscallarg(int) mask;
} */ *uap = v;
register struct sigacts *ps = p->p_sigacts;
/*
* 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.
*/
ps->ps_oldmask = p->p_sigmask;
ps->ps_flags |= SAS_OLDMASK;
p->p_sigmask = SCARG(uap, mask) &~ sigcantmask;
while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0)
/* void */;
/* always return EINTR rather than ERESTART... */
return (EINTR);
}
/* ARGSUSED */
int
sys_sigaltstack(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
register struct sys_sigaltstack_args /* {
syscallarg(struct sigaltstack *) nss;
syscallarg(struct sigaltstack *) oss;
} */ *uap = v;
struct sigacts *psp;
struct sigaltstack ss;
int error;
psp = p->p_sigacts;
if ((psp->ps_flags & SAS_ALTSTACK) == 0)
psp->ps_sigstk.ss_flags |= SS_DISABLE;
if (SCARG(uap, oss) && (error = copyout((caddr_t)&psp->ps_sigstk,
(caddr_t)SCARG(uap, oss), sizeof (struct sigaltstack))))
return (error);
if (SCARG(uap, nss) == 0)
return (0);
error = copyin((caddr_t)SCARG(uap, nss), (caddr_t)&ss, sizeof (ss));
if (error)
return (error);
if (ss.ss_flags & SS_DISABLE) {
if (psp->ps_sigstk.ss_flags & SS_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);
}
/* ARGSUSED */
int
sys_kill(cp, v, retval)
register struct proc *cp;
void *v;
register_t *retval;
{
register struct sys_kill_args /* {
syscallarg(int) pid;
syscallarg(int) signum;
} */ *uap = v;
register struct proc *p;
register struct pcred *pc = cp->p_cred;
#ifdef COMPAT_09
SCARG(uap, pid) = (short) SCARG(uap, pid);
#endif
if ((u_int)SCARG(uap, signum) >= NSIG)
return (EINVAL);
if (SCARG(uap, pid) > 0) {
/* kill single process */
if ((p = pfind(SCARG(uap, pid))) == NULL)
return (ESRCH);
if (!CANSIGNAL(cp, pc, p, SCARG(uap, signum)))
return (EPERM);
if (SCARG(uap, signum))
psignal(p, SCARG(uap, signum));
return (0);
}
switch (SCARG(uap, pid)) {
case -1: /* broadcast signal */
return (killpg1(cp, SCARG(uap, signum), 0, 1));
case 0: /* signal own process group */
return (killpg1(cp, SCARG(uap, signum), 0, 0));
default: /* negative explicit process group */
return (killpg1(cp, SCARG(uap, signum), -SCARG(uap, pid), 0));
}
/* NOTREACHED */
}
/*
* Common code for kill process group/broadcast kill.
* cp is calling process.
*/
int
killpg1(cp, signum, pgid, all)
register struct proc *cp;
int signum, pgid, all;
{
register struct proc *p;
register struct pcred *pc = cp->p_cred;
struct pgrp *pgrp;
int nfound = 0;
if (all)
/*
* broadcast
*/
for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
p == cp || !CANSIGNAL(cp, pc, p, signum))
continue;
nfound++;
if (signum)
psignal(p, signum);
}
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_members.lh_first; p != 0; p = p->p_pglist.le_next) {
if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
p->p_stat == SZOMB ||
!CANSIGNAL(cp, pc, p, signum))
continue;
nfound++;
if (signum)
psignal(p, signum);
}
}
return (nfound ? 0 : ESRCH);
}
/*
* Send a signal to a process group.
*/
void
gsignal(pgid, signum)
int pgid, signum;
{
struct pgrp *pgrp;
if (pgid && (pgrp = pgfind(pgid)))
pgsignal(pgrp, signum, 0);
}
/*
* Send a signal to a process group. If checktty is 1,
* limit to members which have a controlling terminal.
*/
void
pgsignal(pgrp, signum, checkctty)
struct pgrp *pgrp;
int signum, checkctty;
{
register struct proc *p;
if (pgrp)
for (p = pgrp->pg_members.lh_first; p != 0; p = p->p_pglist.le_next)
if (checkctty == 0 || p->p_flag & P_CONTROLT)
psignal(p, signum);
}
/*
* 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, signum, code)
struct proc *p;
register int signum;
u_long code;
{
register struct sigacts *ps = p->p_sigacts;
int mask;
mask = sigmask(signum);
if ((p->p_flag & P_TRACED) == 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, signum, ps->ps_sigact[signum],
p->p_sigmask, code);
#endif
(*p->p_emul->e_sendsig)(ps->ps_sigact[signum], signum,
p->p_sigmask, code);
p->p_sigmask |= ps->ps_catchmask[signum];
if ((ps->ps_sigreset & mask) != 0) {
p->p_sigcatch &= ~mask;
if (signum != SIGCONT && sigprop[signum] & SA_IGNORE)
p->p_sigignore |= mask;
ps->ps_sigact[signum] = SIG_DFL;
}
} else {
ps->ps_code = code; /* XXX for core dump/debugger */
psignal(p, signum);
}
}
/*
* 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, signum)
register struct proc *p;
register int signum;
{
register int s, prop;
register sig_t action;
int mask;
if ((u_int)signum >= NSIG || signum == 0)
panic("psignal signal number");
mask = sigmask(signum);
prop = sigprop[signum];
/*
* If proc is traced, always give parent a chance.
*/
if (p->p_flag & P_TRACED)
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 (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;
if (prop & SA_KILL && p->p_nice > NZERO)
p->p_nice = NZERO;
/*
* 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)
return;
}
}
if (prop & SA_CONT)
p->p_siglist &= ~stopsigmask;
if (prop & SA_STOP)
p->p_siglist &= ~contsigmask;
p->p_siglist |= mask;
/*
* Defer further processing for signals which are held,
* except that stopped processes must be continued by SIGCONT.
*/
if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP))
return;
s = splhigh();
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 ((p->p_flag & P_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) {
p->p_siglist &= ~mask;
goto out;
}
/*
* When a sleeping process receives a stop
* signal, process immediately if possible.
*/
if ((prop & SA_STOP) && action == SIG_DFL) {
/*
* If a child holding parent blocked,
* stopping could cause deadlock.
*/
if (p->p_flag & P_PPWAIT)
goto out;
p->p_siglist &= ~mask;
p->p_xstat = signum;
if ((p->p_pptr->p_flag & P_NOCLDSTOP) == 0)
psignal(p->p_pptr, SIGCHLD);
stop(p);
goto out;
}
/*
* All other (caught or default) signals
* cause the process to run.
*/
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 (signum == 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)
p->p_siglist &= ~mask;
if (action == SIG_CATCH)
goto runfast;
if (p->p_wchan == 0)
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.)
*/
p->p_siglist &= ~mask; /* take it away */
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.
*/
if (p->p_wchan && p->p_flag & P_SINTR)
unsleep(p);
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 == curproc)
signotify(p);
goto out;
}
/*NOTREACHED*/
runfast:
/*
* Raise priority to at least PUSER.
*/
if (p->p_priority > PUSER)
p->p_priority = PUSER;
run:
setrunnable(p);
out:
splx(s);
}
/*
* 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 the CURSIG macro.) The normal call
* sequence is
*
* while (signum = CURSIG(curproc))
* postsig(signum);
*/
int
issignal(p)
register struct proc *p;
{
register int signum, mask, prop;
for (;;) {
mask = p->p_siglist & ~p->p_sigmask;
if (p->p_flag & P_PPWAIT)
mask &= ~stopsigmask;
if (mask == 0) /* no signal to send */
return (0);
signum = ffs((long)mask);
mask = sigmask(signum);
p->p_siglist &= ~mask; /* take the signal! */
/*
* We should see pending but ignored signals
* only if P_TRACED was on when they were posted.
*/
if (mask & p->p_sigignore && (p->p_flag & P_TRACED) == 0)
continue;
if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
/*
* If traced, always stop, and stay
* stopped until released by the debugger.
*/
p->p_xstat = signum;
if (p->p_flag & P_FSTRACE) {
#ifdef PROCFS
/* procfs debugging */
p->p_stat = SSTOP;
wakeup((caddr_t)p);
mi_switch();
#else
panic("procfs debugging");
#endif
} else {
/* ptrace debugging */
psignal(p->p_pptr, SIGCHLD);
do {
stop(p);
mi_switch();
} while (!trace_req(p) && p->p_flag & P_TRACED);
}
/*
* If we are no longer being traced, or the parent
* didn't give us a signal, look for more signals.
*/
if ((p->p_flag & P_TRACED) == 0 || p->p_xstat == 0)
continue;
/*
* If the new signal is being masked, look for other
* signals.
*/
signum = p->p_xstat;
mask = sigmask(signum);
if ((p->p_sigmask & mask) != 0)
continue;
p->p_siglist &= ~mask; /* take the signal! */
}
prop = sigprop[signum];
/*
* Decide whether the signal should be returned.
* Return the signal's number, or fall through
* to clear it from the pending mask.
*/
switch ((long)p->p_sigacts->ps_sigact[signum]) {
case (long)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 %d) got signal %d\n",
p->p_pid, signum);
#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 = signum;
if ((p->p_pptr->p_flag & P_NOCLDSTOP) == 0)
psignal(p->p_pptr, SIGCHLD);
stop(p);
mi_switch();
break;
} else if (prop & SA_IGNORE) {
/*
* Except for SIGCONT, shouldn't get here.
* Default action is to ignore; drop it.
*/
break; /* == ignore */
} else
goto keep;
/*NOTREACHED*/
case (long)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.
*/
goto keep;
}
}
/* NOTREACHED */
keep:
p->p_siglist |= mask; /* leave the signal for later */
return (signum);
}
/*
* 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.
*/
void
stop(p)
register struct proc *p;
{
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(signum)
register int signum;
{
register struct proc *p = curproc;
register struct sigacts *ps = p->p_sigacts;
register sig_t action;
u_long code;
int mask, returnmask;
#ifdef DIAGNOSTIC
if (signum == 0)
panic("postsig");
#endif
mask = sigmask(signum);
p->p_siglist &= ~mask;
action = ps->ps_sigact[signum];
#ifdef KTRACE
if (KTRPOINT(p, KTR_PSIG))
ktrpsig(p->p_tracep,
signum, 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, signum);
/* NOTREACHED */
} else {
/*
* If we get here, the signal must be caught.
*/
#ifdef DIAGNOSTIC
if (action == SIG_IGN || (p->p_sigmask & mask))
panic("postsig 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 (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[signum];
if ((ps->ps_sigreset & mask) != 0) {
p->p_sigcatch &= ~mask;
if (signum != SIGCONT && sigprop[signum] & SA_IGNORE)
p->p_sigignore |= mask;
ps->ps_sigact[signum] = SIG_DFL;
}
(void) spl0();
p->p_stats->p_ru.ru_nsignals++;
if (ps->ps_sig != signum) {
code = 0;
} else {
code = ps->ps_code;
ps->ps_code = 0;
}
(*p->p_emul->e_sendsig)(action, signum, returnmask, code);
}
}
/*
* Kill the current process for stated reason.
*/
void
killproc(p, why)
struct proc *p;
char *why;
{
log(LOG_ERR, "pid %d was killed: %s\n", p->p_pid, why);
uprintf("sorry, pid %d was killed: %s\n", p->p_pid, 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(p, signum)
register struct proc *p;
int signum;
{
p->p_acflag |= AXSIG;
if (sigprop[signum] & SA_CORE) {
p->p_sigacts->ps_sig = signum;
if (coredump(p) == 0)
signum |= WCOREFLAG;
}
exit1(p, W_EXITCODE(0, signum));
/* NOTREACHED */
}
/*
* Dump core, into a file named "progname.core", unless the process was
* setuid/setgid.
*/
int
coredump(p)
register struct proc *p;
{
register struct vnode *vp;
register struct vmspace *vm = p->p_vmspace;
register struct ucred *cred = p->p_cred->pc_ucred;
struct nameidata nd;
struct vattr vattr;
int error, error1;
char name[MAXCOMLEN+6]; /* progname.core */
struct core core;
/*
* Make sure the process has not set-id, to prevent data leaks.
*/
if (p->p_flag & P_SUGID)
return (EPERM);
/*
* Refuse to core if the data + stack + user size is larger than
* the core dump limit. XXX THIS IS WRONG, because of mapped
* data.
*/
if (USPACE + ctob(vm->vm_dsize + vm->vm_ssize) >=
p->p_rlimit[RLIMIT_CORE].rlim_cur)
return (EFBIG); /* better error code? */
/*
* The core dump will go in the current working directory. Make
* sure that mount flags allow us to write core dumps there.
*/
if (p->p_fd->fd_cdir->v_mount->mnt_flag & MNT_NOCOREDUMP)
return (EPERM);
sprintf(name, "%s.core", p->p_comm);
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, name, p);
error = vn_open(&nd, O_CREAT | FWRITE, S_IRUSR | S_IWUSR);
if (error)
return (error);
vp = nd.ni_vp;
/* Don't dump to non-regular files or files with links. */
if (vp->v_type != VREG ||
VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) {
error = EINVAL;
goto out;
}
VATTR_NULL(&vattr);
vattr.va_size = 0;
VOP_LEASE(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);
core.c_midmag = 0;
strncpy(core.c_name, p->p_comm, MAXCOMLEN);
core.c_nseg = 0;
core.c_signo = p->p_sigacts->ps_sig;
core.c_ucode = p->p_sigacts->ps_code;
core.c_cpusize = 0;
core.c_tsize = (u_long)ctob(vm->vm_tsize);
core.c_dsize = (u_long)ctob(vm->vm_dsize);
core.c_ssize = (u_long)round_page(ctob(vm->vm_ssize));
error = cpu_coredump(p, vp, cred, &core);
if (error)
goto out;
if (core.c_midmag == 0) {
/* XXX
* cpu_coredump() didn't bother to set the magic; assume
* this is a request to do a traditional dump. cpu_coredump()
* is still responsible for setting sensible values in
* the core header.
*/
if (core.c_cpusize == 0)
core.c_cpusize = USPACE; /* Just in case */
error = vn_rdwr(UIO_WRITE, vp, vm->vm_daddr,
(int)core.c_dsize,
(off_t)core.c_cpusize, UIO_USERSPACE,
IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
if (error)
goto out;
error = vn_rdwr(UIO_WRITE, vp,
(caddr_t) trunc_page(USRSTACK - ctob(vm->vm_ssize)),
core.c_ssize,
(off_t)(core.c_cpusize + core.c_dsize), UIO_USERSPACE,
IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
} else {
/*
* vm_coredump() spits out all appropriate segments.
* All that's left to do is to write the core header.
*/
error = vm_coredump(p, vp, cred, &core);
if (error)
goto out;
error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&core,
(int)core.c_hdrsize, (off_t)0,
UIO_SYSSPACE, 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);
}
/*
* Nonexistent system call-- signal process (may want to handle it).
* Flag error in case process won't see signal immediately (blocked or ignored).
*/
/* ARGSUSED */
int
sys_nosys(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
psignal(p, SIGSYS);
return (ENOSYS);
}
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