freebsd-skq/sys/kern/kern_sig.c

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1994-05-24 10:09:53 +00:00
/*
* 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.
* 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
*/
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#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include "opt_ktrace.h"
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#include <sys/param.h>
#include <sys/systm.h>
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#include <sys/signalvar.h>
#include <sys/vnode.h>
#include <sys/acct.h>
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#include <sys/condvar.h>
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#include <sys/event.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/kse.h>
#include <sys/ktr.h>
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#include <sys/ktrace.h>
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#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/pioctl.h>
#include <sys/resourcevar.h>
Switch the sleep/wakeup and condition variable implementations to use the sleep queue interface: - Sleep queues attempt to merge some of the benefits of both sleep queues and condition variables. Having sleep qeueus in a hash table avoids having to allocate a queue head for each wait channel. Thus, struct cv has shrunk down to just a single char * pointer now. However, the hash table does not hold threads directly, but queue heads. This means that once you have located a queue in the hash bucket, you no longer have to walk the rest of the hash chain looking for threads. Instead, you have a list of all the threads sleeping on that wait channel. - Outside of the sleepq code and the sleep/cv code the kernel no longer differentiates between cv's and sleep/wakeup. For example, calls to abortsleep() and cv_abort() are replaced with a call to sleepq_abort(). Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and cv_waitq_remove() have been replaced with calls to sleepq_remove(). - The sched_sleep() function no longer accepts a priority argument as sleep's no longer inherently bump the priority. Instead, this is soley a propery of msleep() which explicitly calls sched_prio() before blocking. - The TDF_ONSLEEPQ flag has been dropped as it was never used. The associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been dropped and replaced with a single explicit clearing of td_wchan. TD_SET_ONSLEEPQ() would really have only made sense if it had taken the wait channel and message as arguments anyway. Now that that only happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
#include <sys/sleepqueue.h>
Overhaul of the SMP code. Several portions of the SMP kernel support have been made machine independent and various other adjustments have been made to support Alpha SMP. - It splits the per-process portions of hardclock() and statclock() off into hardclock_process() and statclock_process() respectively. hardclock() and statclock() call the *_process() functions for the current process so that UP systems will run as before. For SMP systems, it is simply necessary to ensure that all other processors execute the *_process() functions when the main clock functions are triggered on one CPU by an interrupt. For the alpha 4100, clock interrupts are delievered in a staggered broadcast fashion, so we simply call hardclock/statclock on the boot CPU and call the *_process() functions on the secondaries. For x86, we call statclock and hardclock as usual and then call forward_hardclock/statclock in the MD code to send an IPI to cause the AP's to execute forwared_hardclock/statclock which then call the *_process() functions. - forward_signal() and forward_roundrobin() have been reworked to be MI and to involve less hackery. Now the cpu doing the forward sets any flags, etc. and sends a very simple IPI_AST to the other cpu(s). AST IPIs now just basically return so that they can execute ast() and don't bother with setting the astpending or needresched flags themselves. This also removes the loop in forward_signal() as sched_lock closes the race condition that the loop worked around. - need_resched(), resched_wanted() and clear_resched() have been changed to take a process to act on rather than assuming curproc so that they can be used to implement forward_roundrobin() as described above. - Various other SMP variables have been moved to a MI subr_smp.c and a new header sys/smp.h declares MI SMP variables and API's. The IPI API's from machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h. - The globaldata_register() and globaldata_find() functions as well as the SLIST of globaldata structures has become MI and moved into subr_smp.c. Also, the globaldata list is only available if SMP support is compiled in. Reviewed by: jake, peter Looked over by: eivind
2001-04-27 19:28:25 +00:00
#include <sys/smp.h>
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#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
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#include <sys/sysent.h>
#include <sys/syslog.h>
#include <sys/sysproto.h>
#include <sys/unistd.h>
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#include <sys/wait.h>
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#include <machine/cpu.h>
#if defined (__alpha__) && !defined(COMPAT_43)
#error "You *really* need COMPAT_43 on the alpha for longjmp(3)"
#endif
#define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
static int coredump(struct thread *);
static char *expand_name(const char *, uid_t, pid_t);
static int killpg1(struct thread *td, int sig, int pgid, int all);
static int issignal(struct thread *p);
static int sigprop(int sig);
static void stop(struct proc *);
static void tdsigwakeup(struct thread *td, int sig, sig_t action);
static int filt_sigattach(struct knote *kn);
static void filt_sigdetach(struct knote *kn);
static int filt_signal(struct knote *kn, long hint);
static struct thread *sigtd(struct proc *p, int sig, int prop);
static int kern_sigtimedwait(struct thread *td, sigset_t set,
siginfo_t *info, struct timespec *timeout);
static void do_tdsignal(struct thread *td, int sig, sigtarget_t target);
struct filterops sig_filtops =
{ 0, filt_sigattach, filt_sigdetach, filt_signal };
static int kern_logsigexit = 1;
SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
&kern_logsigexit, 0,
"Log processes quitting on abnormal signals to syslog(3)");
/*
* Policy -- Can ucred cr1 send SIGIO to process cr2?
* Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
* in the right situations.
*/
#define CANSIGIO(cr1, cr2) \
((cr1)->cr_uid == 0 || \
(cr1)->cr_ruid == (cr2)->cr_ruid || \
(cr1)->cr_uid == (cr2)->cr_ruid || \
(cr1)->cr_ruid == (cr2)->cr_uid || \
(cr1)->cr_uid == (cr2)->cr_uid)
int sugid_coredump;
SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
&sugid_coredump, 0, "Enable coredumping set user/group ID processes");
static int do_coredump = 1;
SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
&do_coredump, 0, "Enable/Disable coredumps");
/*
* Signal properties and actions.
* The array below categorizes the signals and their default actions
* according to the following properties:
*/
#define SA_KILL 0x01 /* terminates process by default */
#define SA_CORE 0x02 /* ditto and coredumps */
#define SA_STOP 0x04 /* suspend process */
#define SA_TTYSTOP 0x08 /* ditto, from tty */
#define SA_IGNORE 0x10 /* ignore by default */
#define SA_CONT 0x20 /* continue if suspended */
#define SA_CANTMASK 0x40 /* non-maskable, catchable */
#define SA_PROC 0x80 /* deliverable to any thread */
static int sigproptbl[NSIG] = {
SA_KILL|SA_PROC, /* SIGHUP */
SA_KILL|SA_PROC, /* SIGINT */
SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */
SA_KILL|SA_CORE, /* SIGILL */
SA_KILL|SA_CORE, /* SIGTRAP */
SA_KILL|SA_CORE, /* SIGABRT */
SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */
SA_KILL|SA_CORE, /* SIGFPE */
SA_KILL|SA_PROC, /* SIGKILL */
SA_KILL|SA_CORE, /* SIGBUS */
SA_KILL|SA_CORE, /* SIGSEGV */
SA_KILL|SA_CORE, /* SIGSYS */
SA_KILL|SA_PROC, /* SIGPIPE */
SA_KILL|SA_PROC, /* SIGALRM */
SA_KILL|SA_PROC, /* SIGTERM */
SA_IGNORE|SA_PROC, /* SIGURG */
SA_STOP|SA_PROC, /* SIGSTOP */
SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */
SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */
SA_IGNORE|SA_PROC, /* SIGCHLD */
SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */
SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */
SA_IGNORE|SA_PROC, /* SIGIO */
SA_KILL, /* SIGXCPU */
SA_KILL, /* SIGXFSZ */
SA_KILL|SA_PROC, /* SIGVTALRM */
SA_KILL|SA_PROC, /* SIGPROF */
SA_IGNORE|SA_PROC, /* SIGWINCH */
SA_IGNORE|SA_PROC, /* SIGINFO */
SA_KILL|SA_PROC, /* SIGUSR1 */
SA_KILL|SA_PROC, /* SIGUSR2 */
};
/*
* Determine signal that should be delivered to process p, the current
* process, 0 if none. If there is a pending stop signal with default
* action, the process stops in issignal().
* XXXKSE the check for a pending stop is not done under KSE
*
* MP SAFE.
*/
int
cursig(struct thread *td)
{
PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED);
mtx_assert(&sched_lock, MA_NOTOWNED);
return (SIGPENDING(td) ? issignal(td) : 0);
}
/*
* Arrange for ast() to handle unmasked pending signals on return to user
* mode. This must be called whenever a signal is added to td_siglist or
* unmasked in td_sigmask.
*/
void
signotify(struct thread *td)
{
struct proc *p;
sigset_t set, saved;
p = td->td_proc;
PROC_LOCK_ASSERT(p, MA_OWNED);
/*
* If our mask changed we may have to move signal that were
* previously masked by all threads to our siglist.
*/
set = p->p_siglist;
if (p->p_flag & P_SA)
saved = p->p_siglist;
SIGSETNAND(set, td->td_sigmask);
SIGSETNAND(p->p_siglist, set);
SIGSETOR(td->td_siglist, set);
if (SIGPENDING(td)) {
mtx_lock_spin(&sched_lock);
td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING;
mtx_unlock_spin(&sched_lock);
}
if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
if (SIGSETEQ(saved, p->p_siglist))
return;
else {
/* pending set changed */
p->p_flag |= P_SIGEVENT;
wakeup(&p->p_siglist);
}
}
}
int
sigonstack(size_t sp)
{
struct thread *td = curthread;
return ((td->td_pflags & TDP_ALTSTACK) ?
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
((td->td_sigstk.ss_size == 0) ?
(td->td_sigstk.ss_flags & SS_ONSTACK) :
((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size))
#else
((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)
#endif
: 0);
}
static __inline int
sigprop(int sig)
{
if (sig > 0 && sig < NSIG)
return (sigproptbl[_SIG_IDX(sig)]);
return (0);
}
int
sig_ffs(sigset_t *set)
{
int i;
for (i = 0; i < _SIG_WORDS; i++)
if (set->__bits[i])
return (ffs(set->__bits[i]) + (i * 32));
return (0);
}
/*
* kern_sigaction
* sigaction
* freebsd4_sigaction
* osigaction
*
* MPSAFE
*/
int
kern_sigaction(td, sig, act, oact, flags)
struct thread *td;
register int sig;
struct sigaction *act, *oact;
int flags;
{
struct sigacts *ps;
struct thread *td0;
struct proc *p = td->td_proc;
if (!_SIG_VALID(sig))
return (EINVAL);
PROC_LOCK(p);
ps = p->p_sigacts;
mtx_lock(&ps->ps_mtx);
if (oact) {
oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
oact->sa_flags = 0;
if (SIGISMEMBER(ps->ps_sigonstack, sig))
oact->sa_flags |= SA_ONSTACK;
if (!SIGISMEMBER(ps->ps_sigintr, sig))
oact->sa_flags |= SA_RESTART;
if (SIGISMEMBER(ps->ps_sigreset, sig))
oact->sa_flags |= SA_RESETHAND;
if (SIGISMEMBER(ps->ps_signodefer, sig))
oact->sa_flags |= SA_NODEFER;
if (SIGISMEMBER(ps->ps_siginfo, sig))
oact->sa_flags |= SA_SIGINFO;
if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP)
oact->sa_flags |= SA_NOCLDSTOP;
if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT)
oact->sa_flags |= SA_NOCLDWAIT;
}
if (act) {
if ((sig == SIGKILL || sig == SIGSTOP) &&
act->sa_handler != SIG_DFL) {
mtx_unlock(&ps->ps_mtx);
PROC_UNLOCK(p);
return (EINVAL);
}
/*
* Change setting atomically.
*/
ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
if (act->sa_flags & SA_SIGINFO) {
ps->ps_sigact[_SIG_IDX(sig)] =
(__sighandler_t *)act->sa_sigaction;
SIGADDSET(ps->ps_siginfo, sig);
} else {
ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
SIGDELSET(ps->ps_siginfo, sig);
}
if (!(act->sa_flags & SA_RESTART))
SIGADDSET(ps->ps_sigintr, sig);
else
SIGDELSET(ps->ps_sigintr, sig);
if (act->sa_flags & SA_ONSTACK)
SIGADDSET(ps->ps_sigonstack, sig);
else
SIGDELSET(ps->ps_sigonstack, sig);
if (act->sa_flags & SA_RESETHAND)
SIGADDSET(ps->ps_sigreset, sig);
else
SIGDELSET(ps->ps_sigreset, sig);
if (act->sa_flags & SA_NODEFER)
SIGADDSET(ps->ps_signodefer, sig);
else
SIGDELSET(ps->ps_signodefer, sig);
#ifdef COMPAT_SUNOS
if (act->sa_flags & SA_USERTRAMP)
SIGADDSET(ps->ps_usertramp, sig);
else
SIGDELSET(ps->ps_usertramp, sig);
#endif
if (sig == SIGCHLD) {
if (act->sa_flags & SA_NOCLDSTOP)
ps->ps_flag |= PS_NOCLDSTOP;
else
ps->ps_flag &= ~PS_NOCLDSTOP;
if (act->sa_flags & SA_NOCLDWAIT) {
/*
* Paranoia: since SA_NOCLDWAIT is implemented
* by reparenting the dying child to PID 1 (and
* trust it to reap the zombie), PID 1 itself
* is forbidden to set SA_NOCLDWAIT.
*/
if (p->p_pid == 1)
ps->ps_flag &= ~PS_NOCLDWAIT;
else
ps->ps_flag |= PS_NOCLDWAIT;
} else
ps->ps_flag &= ~PS_NOCLDWAIT;
if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
ps->ps_flag |= PS_CLDSIGIGN;
else
ps->ps_flag &= ~PS_CLDSIGIGN;
}
/*
* Set bit in ps_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 ps_sigignore, as we
* have to restart the process.
*/
if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
(sigprop(sig) & SA_IGNORE &&
ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
if ((p->p_flag & P_SA) &&
SIGISMEMBER(p->p_siglist, sig)) {
p->p_flag |= P_SIGEVENT;
wakeup(&p->p_siglist);
}
/* never to be seen again */
SIGDELSET(p->p_siglist, sig);
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td0)
SIGDELSET(td0->td_siglist, sig);
mtx_unlock_spin(&sched_lock);
if (sig != SIGCONT)
/* easier in psignal */
SIGADDSET(ps->ps_sigignore, sig);
SIGDELSET(ps->ps_sigcatch, sig);
} else {
SIGDELSET(ps->ps_sigignore, sig);
if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
SIGDELSET(ps->ps_sigcatch, sig);
else
SIGADDSET(ps->ps_sigcatch, sig);
}
#ifdef COMPAT_FREEBSD4
if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
(flags & KSA_FREEBSD4) == 0)
SIGDELSET(ps->ps_freebsd4, sig);
else
SIGADDSET(ps->ps_freebsd4, sig);
#endif
#ifdef COMPAT_43
if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL ||
(flags & KSA_OSIGSET) == 0)
SIGDELSET(ps->ps_osigset, sig);
else
SIGADDSET(ps->ps_osigset, sig);
#endif
}
mtx_unlock(&ps->ps_mtx);
PROC_UNLOCK(p);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
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struct sigaction_args {
int sig;
struct sigaction *act;
struct sigaction *oact;
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};
#endif
/*
* MPSAFE
*/
int
sigaction(td, uap)
struct thread *td;
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register struct sigaction_args *uap;
{
struct sigaction act, oact;
register struct sigaction *actp, *oactp;
int error;
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actp = (uap->act != NULL) ? &act : NULL;
oactp = (uap->oact != NULL) ? &oact : NULL;
if (actp) {
error = copyin(uap->act, actp, sizeof(act));
if (error)
return (error);
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}
error = kern_sigaction(td, uap->sig, actp, oactp, 0);
if (oactp && !error)
error = copyout(oactp, uap->oact, sizeof(oact));
return (error);
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}
#ifdef COMPAT_FREEBSD4
#ifndef _SYS_SYSPROTO_H_
struct freebsd4_sigaction_args {
int sig;
struct sigaction *act;
struct sigaction *oact;
};
#endif
/*
* MPSAFE
*/
int
freebsd4_sigaction(td, uap)
struct thread *td;
register struct freebsd4_sigaction_args *uap;
{
struct sigaction act, oact;
register struct sigaction *actp, *oactp;
int error;
actp = (uap->act != NULL) ? &act : NULL;
oactp = (uap->oact != NULL) ? &oact : NULL;
if (actp) {
error = copyin(uap->act, actp, sizeof(act));
if (error)
return (error);
}
error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
if (oactp && !error)
error = copyout(oactp, uap->oact, sizeof(oact));
return (error);
}
#endif /* COMAPT_FREEBSD4 */
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
#ifndef _SYS_SYSPROTO_H_
struct osigaction_args {
int signum;
struct osigaction *nsa;
struct osigaction *osa;
};
#endif
/*
* MPSAFE
*/
int
osigaction(td, uap)
struct thread *td;
register struct osigaction_args *uap;
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{
struct osigaction sa;
struct sigaction nsa, osa;
register struct sigaction *nsap, *osap;
int error;
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if (uap->signum <= 0 || uap->signum >= ONSIG)
return (EINVAL);
nsap = (uap->nsa != NULL) ? &nsa : NULL;
osap = (uap->osa != NULL) ? &osa : NULL;
if (nsap) {
error = copyin(uap->nsa, &sa, sizeof(sa));
if (error)
return (error);
nsap->sa_handler = sa.sa_handler;
nsap->sa_flags = sa.sa_flags;
OSIG2SIG(sa.sa_mask, nsap->sa_mask);
Implement SA_SIGINFO for i386. Thanks to Bruce Evans for much more than a review, this was a nice puzzle. This is supposed to be binary and source compatible with older applications that access the old FreeBSD-style three arguments to a signal handler. Except those applications that access hidden signal handler arguments bejond the documented third one. If you have applications that do, please let me know so that we take the opportunity to provide the functionality they need in a documented manner. Also except application that use 'struct sigframe' directly. You need to recompile gdb and doscmd. `make world` is recommended. Example program that demonstrates how SA_SIGINFO and old-style FreeBSD handlers (with their three args) may be used in the same process is at http://www3.cons.org/tmp/fbsd-siginfo.c Programs that use the old FreeBSD-style three arguments are easy to change to SA_SIGINFO (although they don't need to, since the old style will still work): Old args to signal handler: void handler_sn(int sig, int code, struct sigcontext *scp) New args: void handler_si(int sig, siginfo_t *si, void *third) where: old:code == new:second->si_code old:scp == &(new:si->si_scp) /* Passed by value! */ The latter is also pointed to by new:third, but accessing via si->si_scp is preferred because it is type-save. FreeBSD implementation notes: - This is just the framework to make the interface POSIX compatible. For now, no additional functionality is provided. This is supposed to happen now, starting with floating point values. - We don't use 'sigcontext_t.si_value' for now (POSIX meant it for realtime-related values). - Documentation will be updated when new functionality is added and the exact arguments passed are determined. The comments in sys/signal.h are meant to be useful. Reviewed by: BDE
1999-07-06 07:13:48 +00:00
}
error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
if (osap && !error) {
sa.sa_handler = osap->sa_handler;
sa.sa_flags = osap->sa_flags;
SIG2OSIG(osap->sa_mask, sa.sa_mask);
error = copyout(&sa, uap->osa, sizeof(sa));
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}
return (error);
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}
#if !defined(__i386__) && !defined(__alpha__)
/* Avoid replicating the same stub everywhere */
int
osigreturn(td, uap)
struct thread *td;
struct osigreturn_args *uap;
{
return (nosys(td, (struct nosys_args *)uap));
}
#endif
#endif /* COMPAT_43 */
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/*
* Initialize signal state for process 0;
* set to ignore signals that are ignored by default.
*/
void
siginit(p)
struct proc *p;
{
register int i;
struct sigacts *ps;
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PROC_LOCK(p);
ps = p->p_sigacts;
mtx_lock(&ps->ps_mtx);
for (i = 1; i <= NSIG; i++)
if (sigprop(i) & SA_IGNORE && i != SIGCONT)
SIGADDSET(ps->ps_sigignore, i);
mtx_unlock(&ps->ps_mtx);
PROC_UNLOCK(p);
1994-05-24 10:09:53 +00:00
}
/*
* Reset signals for an exec of the specified process.
*/
void
execsigs(struct proc *p)
1994-05-24 10:09:53 +00:00
{
struct sigacts *ps;
int sig;
struct thread *td;
1994-05-24 10:09:53 +00:00
/*
* Reset caught signals. Held signals remain held
* through td_sigmask (unless they were caught,
1994-05-24 10:09:53 +00:00
* and are now ignored by default).
*/
PROC_LOCK_ASSERT(p, MA_OWNED);
td = FIRST_THREAD_IN_PROC(p);
ps = p->p_sigacts;
mtx_lock(&ps->ps_mtx);
while (SIGNOTEMPTY(ps->ps_sigcatch)) {
sig = sig_ffs(&ps->ps_sigcatch);
SIGDELSET(ps->ps_sigcatch, sig);
if (sigprop(sig) & SA_IGNORE) {
if (sig != SIGCONT)
SIGADDSET(ps->ps_sigignore, sig);
SIGDELSET(p->p_siglist, sig);
/*
* There is only one thread at this point.
*/
SIGDELSET(td->td_siglist, sig);
1994-05-24 10:09:53 +00:00
}
ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
1994-05-24 10:09:53 +00:00
}
/*
* Reset stack state to the user stack.
* Clear set of signals caught on the signal stack.
*/
td->td_sigstk.ss_flags = SS_DISABLE;
td->td_sigstk.ss_size = 0;
td->td_sigstk.ss_sp = 0;
td->td_pflags &= ~TDP_ALTSTACK;
/*
* Reset no zombies if child dies flag as Solaris does.
*/
ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
mtx_unlock(&ps->ps_mtx);
1994-05-24 10:09:53 +00:00
}
/*
* kern_sigprocmask()
*
* Manipulate signal mask.
1994-05-24 10:09:53 +00:00
*/
int
kern_sigprocmask(td, how, set, oset, old)
struct thread *td;
int how;
sigset_t *set, *oset;
int old;
{
int error;
PROC_LOCK(td->td_proc);
if (oset != NULL)
*oset = td->td_sigmask;
error = 0;
if (set != NULL) {
switch (how) {
case SIG_BLOCK:
SIG_CANTMASK(*set);
SIGSETOR(td->td_sigmask, *set);
break;
case SIG_UNBLOCK:
SIGSETNAND(td->td_sigmask, *set);
signotify(td);
break;
case SIG_SETMASK:
SIG_CANTMASK(*set);
if (old)
SIGSETLO(td->td_sigmask, *set);
else
td->td_sigmask = *set;
signotify(td);
break;
default:
error = EINVAL;
break;
}
}
PROC_UNLOCK(td->td_proc);
return (error);
}
/*
* sigprocmask() - MP SAFE
*/
#ifndef _SYS_SYSPROTO_H_
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struct sigprocmask_args {
int how;
const sigset_t *set;
sigset_t *oset;
1994-05-24 10:09:53 +00:00
};
#endif
int
sigprocmask(td, uap)
register struct thread *td;
1994-05-24 10:09:53 +00:00
struct sigprocmask_args *uap;
{
sigset_t set, oset;
sigset_t *setp, *osetp;
int error;
1994-05-24 10:09:53 +00:00
setp = (uap->set != NULL) ? &set : NULL;
osetp = (uap->oset != NULL) ? &oset : NULL;
if (setp) {
error = copyin(uap->set, setp, sizeof(set));
if (error)
return (error);
}
error = kern_sigprocmask(td, uap->how, setp, osetp, 0);
if (osetp && !error) {
error = copyout(osetp, uap->oset, sizeof(oset));
}
return (error);
}
1994-05-24 10:09:53 +00:00
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
/*
* osigprocmask() - MP SAFE
*/
#ifndef _SYS_SYSPROTO_H_
struct osigprocmask_args {
int how;
osigset_t mask;
};
#endif
int
osigprocmask(td, uap)
register struct thread *td;
struct osigprocmask_args *uap;
{
sigset_t set, oset;
int error;
1995-05-30 08:16:23 +00:00
OSIG2SIG(uap->mask, set);
error = kern_sigprocmask(td, uap->how, &set, &oset, 1);
SIG2OSIG(oset, td->td_retval[0]);
1994-05-24 10:09:53 +00:00
return (error);
}
#endif /* COMPAT_43 */
1994-05-24 10:09:53 +00:00
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct sigpending_args {
sigset_t *set;
1994-05-24 10:09:53 +00:00
};
#endif
/*
* MPSAFE
*/
int
sigwait(struct thread *td, struct sigwait_args *uap)
{
siginfo_t info;
sigset_t set;
int error;
error = copyin(uap->set, &set, sizeof(set));
if (error)
return (error);
error = kern_sigtimedwait(td, set, &info, NULL);
if (error)
return (error);
error = copyout(&info.si_signo, uap->sig, sizeof(info.si_signo));
/* Repost if we got an error. */
if (error && info.si_signo) {
PROC_LOCK(td->td_proc);
tdsignal(td, info.si_signo, SIGTARGET_TD);
PROC_UNLOCK(td->td_proc);
}
return (error);
}
/*
* MPSAFE
*/
int
sigtimedwait(struct thread *td, struct sigtimedwait_args *uap)
{
struct timespec ts;
struct timespec *timeout;
sigset_t set;
siginfo_t info;
int error;
if (uap->timeout) {
error = copyin(uap->timeout, &ts, sizeof(ts));
if (error)
return (error);
timeout = &ts;
} else
timeout = NULL;
error = copyin(uap->set, &set, sizeof(set));
if (error)
return (error);
error = kern_sigtimedwait(td, set, &info, timeout);
if (error)
return (error);
if (uap->info)
error = copyout(&info, uap->info, sizeof(info));
/* Repost if we got an error. */
if (error && info.si_signo) {
PROC_LOCK(td->td_proc);
tdsignal(td, info.si_signo, SIGTARGET_TD);
PROC_UNLOCK(td->td_proc);
} else {
td->td_retval[0] = info.si_signo;
}
return (error);
}
/*
* MPSAFE
*/
int
sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap)
{
siginfo_t info;
sigset_t set;
int error;
error = copyin(uap->set, &set, sizeof(set));
if (error)
return (error);
error = kern_sigtimedwait(td, set, &info, NULL);
if (error)
return (error);
if (uap->info)
error = copyout(&info, uap->info, sizeof(info));
/* Repost if we got an error. */
if (error && info.si_signo) {
PROC_LOCK(td->td_proc);
tdsignal(td, info.si_signo, SIGTARGET_TD);
PROC_UNLOCK(td->td_proc);
} else {
td->td_retval[0] = info.si_signo;
}
return (error);
}
static int
kern_sigtimedwait(struct thread *td, sigset_t waitset, siginfo_t *info,
struct timespec *timeout)
{
struct sigacts *ps;
sigset_t savedmask, sigset;
struct proc *p;
int error;
int sig;
int hz;
int i;
p = td->td_proc;
error = 0;
sig = 0;
SIG_CANTMASK(waitset);
PROC_LOCK(p);
ps = p->p_sigacts;
savedmask = td->td_sigmask;
again:
for (i = 1; i <= _SIG_MAXSIG; ++i) {
if (!SIGISMEMBER(waitset, i))
continue;
if (SIGISMEMBER(td->td_siglist, i)) {
SIGFILLSET(td->td_sigmask);
SIG_CANTMASK(td->td_sigmask);
SIGDELSET(td->td_sigmask, i);
mtx_lock(&ps->ps_mtx);
sig = cursig(td);
i = 0;
mtx_unlock(&ps->ps_mtx);
} else if (SIGISMEMBER(p->p_siglist, i)) {
if (p->p_flag & P_SA) {
p->p_flag |= P_SIGEVENT;
wakeup(&p->p_siglist);
}
SIGDELSET(p->p_siglist, i);
SIGADDSET(td->td_siglist, i);
SIGFILLSET(td->td_sigmask);
SIG_CANTMASK(td->td_sigmask);
SIGDELSET(td->td_sigmask, i);
mtx_lock(&ps->ps_mtx);
sig = cursig(td);
i = 0;
mtx_unlock(&ps->ps_mtx);
}
if (sig) {
td->td_sigmask = savedmask;
signotify(td);
goto out;
}
}
if (error)
goto out;
td->td_sigmask = savedmask;
signotify(td);
sigset = td->td_siglist;
SIGSETOR(sigset, p->p_siglist);
SIGSETAND(sigset, waitset);
if (!SIGISEMPTY(sigset))
goto again;
/*
* POSIX says this must be checked after looking for pending
* signals.
*/
if (timeout) {
struct timeval tv;
if (timeout->tv_nsec < 0 || timeout->tv_nsec > 1000000000) {
error = EINVAL;
goto out;
}
if (timeout->tv_sec == 0 && timeout->tv_nsec == 0) {
error = EAGAIN;
goto out;
}
TIMESPEC_TO_TIMEVAL(&tv, timeout);
hz = tvtohz(&tv);
} else
hz = 0;
td->td_waitset = &waitset;
error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz);
td->td_waitset = NULL;
if (error == 0) /* surplus wakeup ? */
error = EINTR;
goto again;
out:
if (sig) {
sig_t action;
error = 0;
mtx_lock(&ps->ps_mtx);
action = ps->ps_sigact[_SIG_IDX(sig)];
mtx_unlock(&ps->ps_mtx);
#ifdef KTRACE
if (KTRPOINT(td, KTR_PSIG))
ktrpsig(sig, action, &td->td_sigmask, 0);
#endif
_STOPEVENT(p, S_SIG, sig);
SIGDELSET(td->td_siglist, sig);
info->si_signo = sig;
info->si_code = 0;
}
PROC_UNLOCK(p);
return (error);
}
/*
* MPSAFE
*/
int
sigpending(td, uap)
struct thread *td;
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struct sigpending_args *uap;
{
struct proc *p = td->td_proc;
sigset_t siglist;
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PROC_LOCK(p);
siglist = p->p_siglist;
SIGSETOR(siglist, td->td_siglist);
PROC_UNLOCK(p);
return (copyout(&siglist, uap->set, sizeof(sigset_t)));
}
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
#ifndef _SYS_SYSPROTO_H_
struct osigpending_args {
int dummy;
};
#endif
/*
* MPSAFE
*/
int
osigpending(td, uap)
struct thread *td;
struct osigpending_args *uap;
{
struct proc *p = td->td_proc;
sigset_t siglist;
PROC_LOCK(p);
siglist = p->p_siglist;
SIGSETOR(siglist, td->td_siglist);
PROC_UNLOCK(p);
SIG2OSIG(siglist, td->td_retval[0]);
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return (0);
}
#endif /* COMPAT_43 */
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#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
/*
* Generalized interface signal handler, 4.3-compatible.
*/
#ifndef _SYS_SYSPROTO_H_
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struct osigvec_args {
int signum;
struct sigvec *nsv;
struct sigvec *osv;
};
#endif
/*
* MPSAFE
*/
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/* ARGSUSED */
int
osigvec(td, uap)
struct thread *td;
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register struct osigvec_args *uap;
{
struct sigvec vec;
struct sigaction nsa, osa;
register struct sigaction *nsap, *osap;
int error;
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if (uap->signum <= 0 || uap->signum >= ONSIG)
return (EINVAL);
nsap = (uap->nsv != NULL) ? &nsa : NULL;
osap = (uap->osv != NULL) ? &osa : NULL;
if (nsap) {
error = copyin(uap->nsv, &vec, sizeof(vec));
if (error)
1994-05-24 10:09:53 +00:00
return (error);
nsap->sa_handler = vec.sv_handler;
OSIG2SIG(vec.sv_mask, nsap->sa_mask);
nsap->sa_flags = vec.sv_flags;
nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */
#ifdef COMPAT_SUNOS
nsap->sa_flags |= SA_USERTRAMP;
#endif
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}
error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET);
if (osap && !error) {
vec.sv_handler = osap->sa_handler;
SIG2OSIG(osap->sa_mask, vec.sv_mask);
vec.sv_flags = osap->sa_flags;
vec.sv_flags &= ~SA_NOCLDWAIT;
vec.sv_flags ^= SA_RESTART;
1994-05-24 10:09:53 +00:00
#ifdef COMPAT_SUNOS
vec.sv_flags &= ~SA_NOCLDSTOP;
1994-05-24 10:09:53 +00:00
#endif
error = copyout(&vec, uap->osv, sizeof(vec));
1994-05-24 10:09:53 +00:00
}
return (error);
1994-05-24 10:09:53 +00:00
}
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct osigblock_args {
int mask;
};
#endif
/*
* MPSAFE
*/
int
osigblock(td, uap)
register struct thread *td;
1994-05-24 10:09:53 +00:00
struct osigblock_args *uap;
{
struct proc *p = td->td_proc;
sigset_t set;
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OSIG2SIG(uap->mask, set);
SIG_CANTMASK(set);
PROC_LOCK(p);
SIG2OSIG(td->td_sigmask, td->td_retval[0]);
SIGSETOR(td->td_sigmask, set);
PROC_UNLOCK(p);
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return (0);
}
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct osigsetmask_args {
int mask;
};
#endif
/*
* MPSAFE
*/
int
osigsetmask(td, uap)
struct thread *td;
1994-05-24 10:09:53 +00:00
struct osigsetmask_args *uap;
{
struct proc *p = td->td_proc;
sigset_t set;
1994-05-24 10:09:53 +00:00
OSIG2SIG(uap->mask, set);
SIG_CANTMASK(set);
PROC_LOCK(p);
SIG2OSIG(td->td_sigmask, td->td_retval[0]);
SIGSETLO(td->td_sigmask, set);
signotify(td);
PROC_UNLOCK(p);
1994-05-24 10:09:53 +00:00
return (0);
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
/*
* Suspend process until signal, providing mask to be set
* in the meantime.
***** XXXKSE this doesn't make sense under KSE.
***** Do we suspend the thread or all threads in the process?
***** How do we suspend threads running NOW on another processor?
1994-05-24 10:09:53 +00:00
*/
#ifndef _SYS_SYSPROTO_H_
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struct sigsuspend_args {
const sigset_t *sigmask;
1994-05-24 10:09:53 +00:00
};
#endif
/*
* MPSAFE
*/
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
sigsuspend(td, uap)
struct thread *td;
1994-05-24 10:09:53 +00:00
struct sigsuspend_args *uap;
{
sigset_t mask;
int error;
error = copyin(uap->sigmask, &mask, sizeof(mask));
if (error)
return (error);
return (kern_sigsuspend(td, mask));
}
int
kern_sigsuspend(struct thread *td, sigset_t mask)
{
struct proc *p = td->td_proc;
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/*
* When returning from sigsuspend, we want
1994-05-24 10:09:53 +00:00
* 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.
*/
PROC_LOCK(p);
td->td_oldsigmask = td->td_sigmask;
td->td_pflags |= TDP_OLDMASK;
SIG_CANTMASK(mask);
td->td_sigmask = mask;
signotify(td);
while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0)
/* void */;
PROC_UNLOCK(p);
/* always return EINTR rather than ERESTART... */
return (EINTR);
}
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
/*
* Compatibility sigsuspend call for old binaries. Note nonstandard calling
* convention: libc stub passes mask, not pointer, to save a copyin.
*/
#ifndef _SYS_SYSPROTO_H_
struct osigsuspend_args {
osigset_t mask;
};
#endif
/*
* MPSAFE
*/
/* ARGSUSED */
int
osigsuspend(td, uap)
struct thread *td;
struct osigsuspend_args *uap;
{
struct proc *p = td->td_proc;
sigset_t mask;
PROC_LOCK(p);
td->td_oldsigmask = td->td_sigmask;
td->td_pflags |= TDP_OLDMASK;
OSIG2SIG(uap->mask, mask);
SIG_CANTMASK(mask);
SIGSETLO(td->td_sigmask, mask);
signotify(td);
while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0)
1994-05-24 10:09:53 +00:00
/* void */;
PROC_UNLOCK(p);
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/* always return EINTR rather than ERESTART... */
return (EINTR);
}
#endif /* COMPAT_43 */
1994-05-24 10:09:53 +00:00
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct osigstack_args {
struct sigstack *nss;
struct sigstack *oss;
};
#endif
/*
* MPSAFE
*/
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
osigstack(td, uap)
struct thread *td;
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register struct osigstack_args *uap;
{
struct sigstack nss, oss;
int error = 0;
if (uap->nss != NULL) {
error = copyin(uap->nss, &nss, sizeof(nss));
if (error)
return (error);
}
oss.ss_sp = td->td_sigstk.ss_sp;
oss.ss_onstack = sigonstack(cpu_getstack(td));
if (uap->nss != NULL) {
td->td_sigstk.ss_sp = nss.ss_sp;
td->td_sigstk.ss_size = 0;
td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK;
td->td_pflags |= TDP_ALTSTACK;
1994-05-24 10:09:53 +00:00
}
if (uap->oss != NULL)
error = copyout(&oss, uap->oss, sizeof(oss));
return (error);
1994-05-24 10:09:53 +00:00
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct sigaltstack_args {
stack_t *ss;
stack_t *oss;
1994-05-24 10:09:53 +00:00
};
#endif
/*
* MPSAFE
*/
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
sigaltstack(td, uap)
struct thread *td;
1994-05-24 10:09:53 +00:00
register struct sigaltstack_args *uap;
{
stack_t ss, oss;
int error;
if (uap->ss != NULL) {
error = copyin(uap->ss, &ss, sizeof(ss));
if (error)
return (error);
}
error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL,
(uap->oss != NULL) ? &oss : NULL);
if (error)
return (error);
if (uap->oss != NULL)
error = copyout(&oss, uap->oss, sizeof(stack_t));
return (error);
}
int
kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss)
1994-05-24 10:09:53 +00:00
{
struct proc *p = td->td_proc;
int oonstack;
oonstack = sigonstack(cpu_getstack(td));
if (oss != NULL) {
*oss = td->td_sigstk;
oss->ss_flags = (td->td_pflags & TDP_ALTSTACK)
? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
}
if (ss != NULL) {
if (oonstack)
return (EPERM);
if ((ss->ss_flags & ~SS_DISABLE) != 0)
return (EINVAL);
if (!(ss->ss_flags & SS_DISABLE)) {
if (ss->ss_size < p->p_sysent->sv_minsigstksz) {
return (ENOMEM);
}
td->td_sigstk = *ss;
td->td_pflags |= TDP_ALTSTACK;
} else {
td->td_pflags &= ~TDP_ALTSTACK;
}
1994-05-24 10:09:53 +00:00
}
return (0);
1994-05-24 10:09:53 +00:00
}
/*
* Common code for kill process group/broadcast kill.
* cp is calling process.
*/
static int
killpg1(td, sig, pgid, all)
register struct thread *td;
int sig, pgid, all;
{
register struct proc *p;
struct pgrp *pgrp;
int nfound = 0;
1995-05-30 08:16:23 +00:00
if (all) {
1995-05-30 08:16:23 +00:00
/*
* broadcast
*/
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list) {
PROC_LOCK(p);
if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
p == td->td_proc) {
PROC_UNLOCK(p);
continue;
}
if (p_cansignal(td, p, sig) == 0) {
nfound++;
if (sig)
psignal(p, sig);
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
} else {
sx_slock(&proctree_lock);
if (pgid == 0) {
1995-05-30 08:16:23 +00:00
/*
* zero pgid means send to my process group.
*/
pgrp = td->td_proc->p_pgrp;
PGRP_LOCK(pgrp);
} else {
pgrp = pgfind(pgid);
if (pgrp == NULL) {
sx_sunlock(&proctree_lock);
return (ESRCH);
}
}
sx_sunlock(&proctree_lock);
LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
PROC_LOCK(p);
if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) {
PROC_UNLOCK(p);
continue;
}
if (p->p_state == PRS_ZOMBIE) {
PROC_UNLOCK(p);
continue;
}
if (p_cansignal(td, p, sig) == 0) {
nfound++;
if (sig)
psignal(p, sig);
}
PROC_UNLOCK(p);
}
PGRP_UNLOCK(pgrp);
}
return (nfound ? 0 : ESRCH);
}
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct kill_args {
int pid;
int signum;
};
#endif
/*
* MPSAFE
*/
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
kill(td, uap)
register struct thread *td;
1994-05-24 10:09:53 +00:00
register struct kill_args *uap;
{
register struct proc *p;
int error;
1994-05-24 10:09:53 +00:00
if ((u_int)uap->signum > _SIG_MAXSIG)
1994-05-24 10:09:53 +00:00
return (EINVAL);
1994-05-24 10:09:53 +00:00
if (uap->pid > 0) {
/* kill single process */
if ((p = pfind(uap->pid)) == NULL)
return (ESRCH);
error = p_cansignal(td, p, uap->signum);
if (error == 0 && uap->signum)
psignal(p, uap->signum);
PROC_UNLOCK(p);
return (error);
}
switch (uap->pid) {
case -1: /* broadcast signal */
return (killpg1(td, uap->signum, 0, 1));
case 0: /* signal own process group */
return (killpg1(td, uap->signum, 0, 0));
default: /* negative explicit process group */
return (killpg1(td, uap->signum, -uap->pid, 0));
1994-05-24 10:09:53 +00:00
}
/* NOTREACHED */
1994-05-24 10:09:53 +00:00
}
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct okillpg_args {
int pgid;
int signum;
};
#endif
/*
* MPSAFE
*/
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
okillpg(td, uap)
struct thread *td;
1994-05-24 10:09:53 +00:00
register struct okillpg_args *uap;
{
if ((u_int)uap->signum > _SIG_MAXSIG)
1994-05-24 10:09:53 +00:00
return (EINVAL);
return (killpg1(td, uap->signum, uap->pgid, 0));
1994-05-24 10:09:53 +00:00
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
/*
* Send a signal to a process group.
*/
void
gsignal(pgid, sig)
int pgid, sig;
1994-05-24 10:09:53 +00:00
{
struct pgrp *pgrp;
if (pgid != 0) {
sx_slock(&proctree_lock);
pgrp = pgfind(pgid);
sx_sunlock(&proctree_lock);
if (pgrp != NULL) {
pgsignal(pgrp, sig, 0);
PGRP_UNLOCK(pgrp);
}
}
1994-05-24 10:09:53 +00:00
}
/*
* Send a signal to a process group. If checktty is 1,
1994-05-24 10:09:53 +00:00
* limit to members which have a controlling terminal.
*/
void
pgsignal(pgrp, sig, checkctty)
1994-05-24 10:09:53 +00:00
struct pgrp *pgrp;
int sig, checkctty;
1994-05-24 10:09:53 +00:00
{
register struct proc *p;
if (pgrp) {
PGRP_LOCK_ASSERT(pgrp, MA_OWNED);
LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
PROC_LOCK(p);
1994-05-24 10:09:53 +00:00
if (checkctty == 0 || p->p_flag & P_CONTROLT)
psignal(p, sig);
PROC_UNLOCK(p);
}
}
1994-05-24 10:09:53 +00:00
}
/*
* Send a signal caused by a trap to the current thread.
1994-05-24 10:09:53 +00:00
* If it will be caught immediately, deliver it with correct code.
* Otherwise, post it normally.
*
* MPSAFE
1994-05-24 10:09:53 +00:00
*/
void
trapsignal(struct thread *td, int sig, u_long code)
1994-05-24 10:09:53 +00:00
{
struct sigacts *ps;
struct proc *p;
siginfo_t siginfo;
int error;
p = td->td_proc;
if (td->td_flags & TDF_SA) {
if (td->td_mailbox == NULL)
thread_user_enter(p, td);
PROC_LOCK(p);
if (td->td_mailbox) {
SIGDELSET(td->td_sigmask, sig);
mtx_lock_spin(&sched_lock);
/*
* Force scheduling an upcall, so UTS has chance to
* process the signal before thread runs again in
* userland.
*/
if (td->td_upcall)
td->td_upcall->ku_flags |= KUF_DOUPCALL;
mtx_unlock_spin(&sched_lock);
} else {
/* UTS caused a sync signal */
p->p_code = code; /* XXX for core dump/debugger */
p->p_sig = sig; /* XXX to verify code */
sigexit(td, sig);
}
} else {
PROC_LOCK(p);
}
ps = p->p_sigacts;
mtx_lock(&ps->ps_mtx);
if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) &&
!SIGISMEMBER(td->td_sigmask, sig)) {
1994-05-24 10:09:53 +00:00
p->p_stats->p_ru.ru_nsignals++;
#ifdef KTRACE
if (KTRPOINT(curthread, KTR_PSIG))
ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)],
&td->td_sigmask, code);
1994-05-24 10:09:53 +00:00
#endif
if (!(td->td_flags & TDF_SA))
(*p->p_sysent->sv_sendsig)(
ps->ps_sigact[_SIG_IDX(sig)], sig,
&td->td_sigmask, code);
else {
cpu_thread_siginfo(sig, code, &siginfo);
mtx_unlock(&ps->ps_mtx);
PROC_UNLOCK(p);
error = copyout(&siginfo, &td->td_mailbox->tm_syncsig,
sizeof(siginfo));
PROC_LOCK(p);
/* UTS memory corrupted */
if (error)
sigexit(td, SIGILL);
SIGADDSET(td->td_sigmask, sig);
mtx_lock(&ps->ps_mtx);
}
SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
if (!SIGISMEMBER(ps->ps_signodefer, sig))
SIGADDSET(td->td_sigmask, sig);
if (SIGISMEMBER(ps->ps_sigreset, sig)) {
/*
* See kern_sigaction() for origin of this code.
*/
SIGDELSET(ps->ps_sigcatch, sig);
if (sig != SIGCONT &&
sigprop(sig) & SA_IGNORE)
SIGADDSET(ps->ps_sigignore, sig);
ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
}
mtx_unlock(&ps->ps_mtx);
} else {
mtx_unlock(&ps->ps_mtx);
p->p_code = code; /* XXX for core dump/debugger */
p->p_sig = sig; /* XXX to verify code */
tdsignal(td, sig, SIGTARGET_TD);
1994-05-24 10:09:53 +00:00
}
PROC_UNLOCK(p);
1994-05-24 10:09:53 +00:00
}
static struct thread *
sigtd(struct proc *p, int sig, int prop)
{
struct thread *td, *signal_td;
PROC_LOCK_ASSERT(p, MA_OWNED);
/*
* First find a thread in sigwait state and signal belongs to
* its wait set. POSIX's arguments is that speed of delivering signal
* to sigwait thread is faster than delivering signal to user stack.
* If we can not find sigwait thread, then find the first thread in
* the proc that doesn't have this signal masked, an exception is
* if current thread is sending signal to its process, and it does not
* mask the signal, it should get the signal, this is another fast
* way to deliver signal.
*/
signal_td = NULL;
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td) {
if (td->td_waitset != NULL &&
SIGISMEMBER(*(td->td_waitset), sig)) {
mtx_unlock_spin(&sched_lock);
return (td);
}
if (!SIGISMEMBER(td->td_sigmask, sig)) {
if (td == curthread)
signal_td = curthread;
else if (signal_td == NULL)
signal_td = td;
}
}
if (signal_td == NULL)
signal_td = FIRST_THREAD_IN_PROC(p);
mtx_unlock_spin(&sched_lock);
return (signal_td);
}
1994-05-24 10:09:53 +00:00
/*
* 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.
*
* MPSAFE
1994-05-24 10:09:53 +00:00
*/
void
psignal(struct proc *p, int sig)
1994-05-24 10:09:53 +00:00
{
struct thread *td;
int prop;
if (!_SIG_VALID(sig))
panic("psignal(): invalid signal");
PROC_LOCK_ASSERT(p, MA_OWNED);
prop = sigprop(sig);
/*
* Find a thread to deliver the signal to.
*/
td = sigtd(p, sig, prop);
tdsignal(td, sig, SIGTARGET_P);
}
/*
* MPSAFE
*/
void
tdsignal(struct thread *td, int sig, sigtarget_t target)
{
sigset_t saved;
struct proc *p = td->td_proc;
if (p->p_flag & P_SA)
saved = p->p_siglist;
do_tdsignal(td, sig, target);
if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) {
if (SIGSETEQ(saved, p->p_siglist))
return;
else {
/* pending set changed */
p->p_flag |= P_SIGEVENT;
wakeup(&p->p_siglist);
}
}
}
static void
do_tdsignal(struct thread *td, int sig, sigtarget_t target)
{
struct proc *p;
register sig_t action;
sigset_t *siglist;
struct thread *td0;
register int prop;
struct sigacts *ps;
1994-05-24 10:09:53 +00:00
if (!_SIG_VALID(sig))
panic("do_tdsignal(): invalid signal");
p = td->td_proc;
ps = p->p_sigacts;
PROC_LOCK_ASSERT(p, MA_OWNED);
KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
prop = sigprop(sig);
/*
* If the signal is blocked and not destined for this thread, then
* assign it to the process so that we can find it later in the first
* thread that unblocks it. Otherwise, assign it to this thread now.
*/
if (target == SIGTARGET_TD) {
siglist = &td->td_siglist;
} else {
if (!SIGISMEMBER(td->td_sigmask, sig))
siglist = &td->td_siglist;
else if (td->td_waitset != NULL &&
SIGISMEMBER(*(td->td_waitset), sig))
siglist = &td->td_siglist;
else
siglist = &p->p_siglist;
}
1994-05-24 10:09:53 +00:00
/*
* If proc is traced, always give parent a chance;
* if signal event is tracked by procfs, give *that*
* a chance, as well.
1994-05-24 10:09:53 +00:00
*/
if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG)) {
1994-05-24 10:09:53 +00:00
action = SIG_DFL;
} else {
1994-05-24 10:09:53 +00:00
/*
* If the signal is being ignored,
* then we forget about it immediately.
* (Note: we don't set SIGCONT in ps_sigignore,
1994-05-24 10:09:53 +00:00
* and if it is set to SIG_IGN,
* action will be SIG_DFL here.)
*/
mtx_lock(&ps->ps_mtx);
if (SIGISMEMBER(ps->ps_sigignore, sig) ||
(p->p_flag & P_WEXIT)) {
mtx_unlock(&ps->ps_mtx);
1994-05-24 10:09:53 +00:00
return;
}
if (((td->td_waitset == NULL) &&
SIGISMEMBER(td->td_sigmask, sig)) ||
((td->td_waitset != NULL) &&
SIGISMEMBER(td->td_sigmask, sig) &&
!SIGISMEMBER(*(td->td_waitset), sig)))
1994-05-24 10:09:53 +00:00
action = SIG_HOLD;
else if (SIGISMEMBER(ps->ps_sigcatch, sig))
1994-05-24 10:09:53 +00:00
action = SIG_CATCH;
else
action = SIG_DFL;
mtx_unlock(&ps->ps_mtx);
1994-05-24 10:09:53 +00:00
}
if (prop & SA_CONT) {
SIG_STOPSIGMASK(p->p_siglist);
/*
* XXX Should investigate leaving STOP and CONT sigs only in
* the proc's siglist.
*/
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td0)
SIG_STOPSIGMASK(td0->td_siglist);
mtx_unlock_spin(&sched_lock);
}
1994-05-24 10:09:53 +00:00
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))
1994-05-24 10:09:53 +00:00
return;
SIG_CONTSIGMASK(p->p_siglist);
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td0)
SIG_CONTSIGMASK(td0->td_siglist);
mtx_unlock_spin(&sched_lock);
p->p_flag &= ~P_CONTINUED;
1994-05-24 10:09:53 +00:00
}
SIGADDSET(*siglist, sig);
signotify(td); /* uses schedlock */
if (siglist == &td->td_siglist && (td->td_waitset != NULL) &&
action != SIG_HOLD) {
td->td_waitset = NULL;
}
/*
* Defer further processing for signals which are held,
* except that stopped processes must be continued by SIGCONT.
*/
if (action == SIG_HOLD &&
!((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG)))
2003-04-12 02:54:46 +00:00
return;
1994-05-24 10:09:53 +00:00
/*
* Some signals have a process-wide effect and a per-thread
* component. Most processing occurs when the process next
* tries to cross the user boundary, however there are some
* times when processing needs to be done immediatly, such as
* waking up threads so that they can cross the user boundary.
* We try do the per-process part here.
1994-05-24 10:09:53 +00:00
*/
if (P_SHOULDSTOP(p)) {
1994-05-24 10:09:53 +00:00
/*
* The process is in stopped mode. All the threads should be
* either winding down or already on the suspended queue.
1994-05-24 10:09:53 +00:00
*/
if (p->p_flag & P_TRACED) {
/*
* The traced process is already stopped,
* so no further action is necessary.
* No signal can restart us.
*/
goto out;
}
if (sig == SIGKILL) {
/*
* SIGKILL sets process running.
* It will die elsewhere.
* All threads must be restarted.
*/
p->p_flag &= ~P_STOPPED;
goto runfast;
}
if (prop & SA_CONT) {
/*
* If SIGCONT is default (or ignored), we continue the
* process but don't leave the signal in siglist as
* it has no further action. If SIGCONT is held, we
* continue the process and leave the signal in
* siglist. If the process catches SIGCONT, let it
* handle the signal itself. If it isn't waiting on
* an event, it goes back to run state.
* Otherwise, process goes back to sleep state.
*/
p->p_flag &= ~P_STOPPED_SIG;
p->p_flag |= P_CONTINUED;
if (action == SIG_DFL) {
SIGDELSET(*siglist, sig);
} else if (action == SIG_CATCH) {
/*
* The process wants to catch it so it needs
* to run at least one thread, but which one?
* It would seem that the answer would be to
* run an upcall in the next KSE to run, and
* deliver the signal that way. In a NON KSE
* process, we need to make sure that the
* single thread is runnable asap.
* XXXKSE for now however, make them all run.
*/
goto runfast;
}
/*
* The signal is not ignored or caught.
*/
mtx_lock_spin(&sched_lock);
thread_unsuspend(p);
mtx_unlock_spin(&sched_lock);
1994-05-24 10:09:53 +00:00
goto out;
}
if (prop & SA_STOP) {
/*
* Already stopped, don't need to stop again
* (If we did the shell could get confused).
* Just make sure the signal STOP bit set.
*/
p->p_flag |= P_STOPPED_SIG;
SIGDELSET(*siglist, sig);
goto out;
}
1994-05-24 10:09:53 +00:00
/*
* All other kinds of signals:
* If a thread is sleeping interruptibly, simulate a
* wakeup so that when it is continued it will be made
* runnable and can look at the signal. However, don't make
* the PROCESS runnable, leave it stopped.
* It may run a bit until it hits a thread_suspend_check().
1994-05-24 10:09:53 +00:00
*/
mtx_lock_spin(&sched_lock);
Switch the sleep/wakeup and condition variable implementations to use the sleep queue interface: - Sleep queues attempt to merge some of the benefits of both sleep queues and condition variables. Having sleep qeueus in a hash table avoids having to allocate a queue head for each wait channel. Thus, struct cv has shrunk down to just a single char * pointer now. However, the hash table does not hold threads directly, but queue heads. This means that once you have located a queue in the hash bucket, you no longer have to walk the rest of the hash chain looking for threads. Instead, you have a list of all the threads sleeping on that wait channel. - Outside of the sleepq code and the sleep/cv code the kernel no longer differentiates between cv's and sleep/wakeup. For example, calls to abortsleep() and cv_abort() are replaced with a call to sleepq_abort(). Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and cv_waitq_remove() have been replaced with calls to sleepq_remove(). - The sched_sleep() function no longer accepts a priority argument as sleep's no longer inherently bump the priority. Instead, this is soley a propery of msleep() which explicitly calls sched_prio() before blocking. - The TDF_ONSLEEPQ flag has been dropped as it was never used. The associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been dropped and replaced with a single explicit clearing of td_wchan. TD_SET_ONSLEEPQ() would really have only made sense if it had taken the wait channel and message as arguments anyway. Now that that only happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR))
sleepq_abort(td);
mtx_unlock_spin(&sched_lock);
goto out;
1994-05-24 10:09:53 +00:00
/*
2004-03-29 22:46:54 +00:00
* Mutexes are short lived. Threads waiting on them will
* hit thread_suspend_check() soon.
1994-05-24 10:09:53 +00:00
*/
} else if (p->p_state == PRS_NORMAL) {
In the kernel code, we have the tsleep() call with the PCATCH argument. PCATCH means 'if we get a signal, interrupt me!" and tsleep returns either EINTR or ERESTART depending on the circumstances. ERESTART is "special" because it causes the system call to fail, but right as it returns back to userland it tells the trap handler to move %eip back a bit so that userland will immediately re-run the syscall. This is a syscall restart. It only works for things like read() etc where nothing has changed yet. Note that *userland* is tricked into restarting the syscall by the kernel. The kernel doesn't actually do the restart. It is deadly for things like select, poll, nanosleep etc where it might cause the elapsed time to be reset and start again from scratch. So those syscalls do this to prevent userland rerunning the syscall: if (error == ERESTART) error = EINTR; Fake "signals" like SIGTSTP from ^Z etc do not normally invoke userland signal handlers. But, in -current, the PCATCH *is* being triggered and tsleep is returning ERESTART, and the syscall is aborted even though no userland signal handler was run. That is the fault here. We're triggering the PCATCH in cases that we shouldn't. ie: it is being triggered on *any* signal processing, rather than the case where the signal is posted to userland. --- Peter The work of psignal() is a patchwork of special case required by the process debugging and job-control facilities... --- Kirk McKusick "The design and impelementation of the 4.4BSD Operating system" Page 105 in STABLE source, when psignal is posting a STOP signal to sleeping process and the signal action of the process is SIG_DFL, system will directly change the process state from SSLEEP to SSTOP, and when SIGCONT is posted to the stopped process, if it finds that the process is still on sleep queue, the process state will be restored to SSLEEP, and won't wakeup the process. this commit mimics the behaviour in STABLE source tree. Reviewed by: Jon Mini, Tim Robbins, Peter Wemm Approved by: julian@freebsd.org (mentor)
2002-09-03 12:56:01 +00:00
if ((p->p_flag & P_TRACED) || (action != SIG_DFL) ||
!(prop & SA_STOP)) {
mtx_lock_spin(&sched_lock);
tdsigwakeup(td, sig, action);
mtx_unlock_spin(&sched_lock);
1994-05-24 10:09:53 +00:00
goto out;
}
In the kernel code, we have the tsleep() call with the PCATCH argument. PCATCH means 'if we get a signal, interrupt me!" and tsleep returns either EINTR or ERESTART depending on the circumstances. ERESTART is "special" because it causes the system call to fail, but right as it returns back to userland it tells the trap handler to move %eip back a bit so that userland will immediately re-run the syscall. This is a syscall restart. It only works for things like read() etc where nothing has changed yet. Note that *userland* is tricked into restarting the syscall by the kernel. The kernel doesn't actually do the restart. It is deadly for things like select, poll, nanosleep etc where it might cause the elapsed time to be reset and start again from scratch. So those syscalls do this to prevent userland rerunning the syscall: if (error == ERESTART) error = EINTR; Fake "signals" like SIGTSTP from ^Z etc do not normally invoke userland signal handlers. But, in -current, the PCATCH *is* being triggered and tsleep is returning ERESTART, and the syscall is aborted even though no userland signal handler was run. That is the fault here. We're triggering the PCATCH in cases that we shouldn't. ie: it is being triggered on *any* signal processing, rather than the case where the signal is posted to userland. --- Peter The work of psignal() is a patchwork of special case required by the process debugging and job-control facilities... --- Kirk McKusick "The design and impelementation of the 4.4BSD Operating system" Page 105 in STABLE source, when psignal is posting a STOP signal to sleeping process and the signal action of the process is SIG_DFL, system will directly change the process state from SSLEEP to SSTOP, and when SIGCONT is posted to the stopped process, if it finds that the process is still on sleep queue, the process state will be restored to SSLEEP, and won't wakeup the process. this commit mimics the behaviour in STABLE source tree. Reviewed by: Jon Mini, Tim Robbins, Peter Wemm Approved by: julian@freebsd.org (mentor)
2002-09-03 12:56:01 +00:00
if (prop & SA_STOP) {
if (p->p_flag & P_PPWAIT)
goto out;
p->p_flag |= P_STOPPED_SIG;
p->p_xstat = sig;
In the kernel code, we have the tsleep() call with the PCATCH argument. PCATCH means 'if we get a signal, interrupt me!" and tsleep returns either EINTR or ERESTART depending on the circumstances. ERESTART is "special" because it causes the system call to fail, but right as it returns back to userland it tells the trap handler to move %eip back a bit so that userland will immediately re-run the syscall. This is a syscall restart. It only works for things like read() etc where nothing has changed yet. Note that *userland* is tricked into restarting the syscall by the kernel. The kernel doesn't actually do the restart. It is deadly for things like select, poll, nanosleep etc where it might cause the elapsed time to be reset and start again from scratch. So those syscalls do this to prevent userland rerunning the syscall: if (error == ERESTART) error = EINTR; Fake "signals" like SIGTSTP from ^Z etc do not normally invoke userland signal handlers. But, in -current, the PCATCH *is* being triggered and tsleep is returning ERESTART, and the syscall is aborted even though no userland signal handler was run. That is the fault here. We're triggering the PCATCH in cases that we shouldn't. ie: it is being triggered on *any* signal processing, rather than the case where the signal is posted to userland. --- Peter The work of psignal() is a patchwork of special case required by the process debugging and job-control facilities... --- Kirk McKusick "The design and impelementation of the 4.4BSD Operating system" Page 105 in STABLE source, when psignal is posting a STOP signal to sleeping process and the signal action of the process is SIG_DFL, system will directly change the process state from SSLEEP to SSTOP, and when SIGCONT is posted to the stopped process, if it finds that the process is still on sleep queue, the process state will be restored to SSLEEP, and won't wakeup the process. this commit mimics the behaviour in STABLE source tree. Reviewed by: Jon Mini, Tim Robbins, Peter Wemm Approved by: julian@freebsd.org (mentor)
2002-09-03 12:56:01 +00:00
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td0) {
if (TD_IS_SLEEPING(td0) &&
(td0->td_flags & TDF_SINTR) &&
!TD_IS_SUSPENDED(td0)) {
thread_suspend_one(td0);
} else if (td != td0) {
td0->td_flags |= TDF_ASTPENDING;
}
In the kernel code, we have the tsleep() call with the PCATCH argument. PCATCH means 'if we get a signal, interrupt me!" and tsleep returns either EINTR or ERESTART depending on the circumstances. ERESTART is "special" because it causes the system call to fail, but right as it returns back to userland it tells the trap handler to move %eip back a bit so that userland will immediately re-run the syscall. This is a syscall restart. It only works for things like read() etc where nothing has changed yet. Note that *userland* is tricked into restarting the syscall by the kernel. The kernel doesn't actually do the restart. It is deadly for things like select, poll, nanosleep etc where it might cause the elapsed time to be reset and start again from scratch. So those syscalls do this to prevent userland rerunning the syscall: if (error == ERESTART) error = EINTR; Fake "signals" like SIGTSTP from ^Z etc do not normally invoke userland signal handlers. But, in -current, the PCATCH *is* being triggered and tsleep is returning ERESTART, and the syscall is aborted even though no userland signal handler was run. That is the fault here. We're triggering the PCATCH in cases that we shouldn't. ie: it is being triggered on *any* signal processing, rather than the case where the signal is posted to userland. --- Peter The work of psignal() is a patchwork of special case required by the process debugging and job-control facilities... --- Kirk McKusick "The design and impelementation of the 4.4BSD Operating system" Page 105 in STABLE source, when psignal is posting a STOP signal to sleeping process and the signal action of the process is SIG_DFL, system will directly change the process state from SSLEEP to SSTOP, and when SIGCONT is posted to the stopped process, if it finds that the process is still on sleep queue, the process state will be restored to SSLEEP, and won't wakeup the process. this commit mimics the behaviour in STABLE source tree. Reviewed by: Jon Mini, Tim Robbins, Peter Wemm Approved by: julian@freebsd.org (mentor)
2002-09-03 12:56:01 +00:00
}
thread_stopped(p);
if (p->p_numthreads == p->p_suspcount) {
SIGDELSET(p->p_siglist, p->p_xstat);
FOREACH_THREAD_IN_PROC(p, td0)
SIGDELSET(td0->td_siglist, p->p_xstat);
}
mtx_unlock_spin(&sched_lock);
In the kernel code, we have the tsleep() call with the PCATCH argument. PCATCH means 'if we get a signal, interrupt me!" and tsleep returns either EINTR or ERESTART depending on the circumstances. ERESTART is "special" because it causes the system call to fail, but right as it returns back to userland it tells the trap handler to move %eip back a bit so that userland will immediately re-run the syscall. This is a syscall restart. It only works for things like read() etc where nothing has changed yet. Note that *userland* is tricked into restarting the syscall by the kernel. The kernel doesn't actually do the restart. It is deadly for things like select, poll, nanosleep etc where it might cause the elapsed time to be reset and start again from scratch. So those syscalls do this to prevent userland rerunning the syscall: if (error == ERESTART) error = EINTR; Fake "signals" like SIGTSTP from ^Z etc do not normally invoke userland signal handlers. But, in -current, the PCATCH *is* being triggered and tsleep is returning ERESTART, and the syscall is aborted even though no userland signal handler was run. That is the fault here. We're triggering the PCATCH in cases that we shouldn't. ie: it is being triggered on *any* signal processing, rather than the case where the signal is posted to userland. --- Peter The work of psignal() is a patchwork of special case required by the process debugging and job-control facilities... --- Kirk McKusick "The design and impelementation of the 4.4BSD Operating system" Page 105 in STABLE source, when psignal is posting a STOP signal to sleeping process and the signal action of the process is SIG_DFL, system will directly change the process state from SSLEEP to SSTOP, and when SIGCONT is posted to the stopped process, if it finds that the process is still on sleep queue, the process state will be restored to SSLEEP, and won't wakeup the process. this commit mimics the behaviour in STABLE source tree. Reviewed by: Jon Mini, Tim Robbins, Peter Wemm Approved by: julian@freebsd.org (mentor)
2002-09-03 12:56:01 +00:00
goto out;
}
else
1994-05-24 10:09:53 +00:00
goto runfast;
/* NOTREACHED */
} else {
/* Not in "NORMAL" state. discard the signal. */
SIGDELSET(*siglist, sig);
goto out;
}
1994-05-24 10:09:53 +00:00
/*
* The process is not stopped so we need to apply the signal to all the
* running threads.
*/
1994-05-24 10:09:53 +00:00
runfast:
mtx_lock_spin(&sched_lock);
tdsigwakeup(td, sig, action);
thread_unsuspend(p);
mtx_unlock_spin(&sched_lock);
out:
/* If we jump here, sched_lock should not be owned. */
mtx_assert(&sched_lock, MA_NOTOWNED);
}
1994-05-24 10:09:53 +00:00
/*
* The force of a signal has been directed against a single
* thread. We need to see what we can do about knocking it
* out of any sleep it may be in etc.
*/
static void
tdsigwakeup(struct thread *td, int sig, sig_t action)
{
struct proc *p = td->td_proc;
register int prop;
PROC_LOCK_ASSERT(p, MA_OWNED);
mtx_assert(&sched_lock, MA_OWNED);
prop = sigprop(sig);
/*
* Bring the priority of a thread up if we want it to get
* killed in this lifetime.
*/
if ((action == SIG_DFL) && (prop & SA_KILL)) {
if (td->td_priority > PUSER) {
td->td_priority = PUSER;
1994-05-24 10:09:53 +00:00
}
}
if (TD_ON_SLEEPQ(td)) {
/*
* If thread is sleeping uninterruptibly
* we can't interrupt the sleep... the signal will
* be noticed when the process returns through
* trap() or syscall().
*/
Switch the sleep/wakeup and condition variable implementations to use the sleep queue interface: - Sleep queues attempt to merge some of the benefits of both sleep queues and condition variables. Having sleep qeueus in a hash table avoids having to allocate a queue head for each wait channel. Thus, struct cv has shrunk down to just a single char * pointer now. However, the hash table does not hold threads directly, but queue heads. This means that once you have located a queue in the hash bucket, you no longer have to walk the rest of the hash chain looking for threads. Instead, you have a list of all the threads sleeping on that wait channel. - Outside of the sleepq code and the sleep/cv code the kernel no longer differentiates between cv's and sleep/wakeup. For example, calls to abortsleep() and cv_abort() are replaced with a call to sleepq_abort(). Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and cv_waitq_remove() have been replaced with calls to sleepq_remove(). - The sched_sleep() function no longer accepts a priority argument as sleep's no longer inherently bump the priority. Instead, this is soley a propery of msleep() which explicitly calls sched_prio() before blocking. - The TDF_ONSLEEPQ flag has been dropped as it was never used. The associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been dropped and replaced with a single explicit clearing of td_wchan. TD_SET_ONSLEEPQ() would really have only made sense if it had taken the wait channel and message as arguments anyway. Now that that only happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
if ((td->td_flags & TDF_SINTR) == 0)
return;
1994-05-24 10:09:53 +00:00
/*
* Process is sleeping and traced. Make it runnable
* so it can discover the signal in issignal() and stop
* for its parent.
1994-05-24 10:09:53 +00:00
*/
if (p->p_flag & P_TRACED) {
p->p_flag &= ~P_STOPPED_TRACE;
} else {
1994-05-24 10:09:53 +00:00
/*
* If SIGCONT is default (or ignored) and process is
* asleep, we are finished; the process should not
* be awakened.
*/
if ((prop & SA_CONT) && action == SIG_DFL) {
SIGDELSET(p->p_siglist, sig);
/*
* It may be on either list in this state.
* Remove from both for now.
*/
SIGDELSET(td->td_siglist, sig);
return;
}
/*
* Raise priority to at least PUSER.
*/
Switch the sleep/wakeup and condition variable implementations to use the sleep queue interface: - Sleep queues attempt to merge some of the benefits of both sleep queues and condition variables. Having sleep qeueus in a hash table avoids having to allocate a queue head for each wait channel. Thus, struct cv has shrunk down to just a single char * pointer now. However, the hash table does not hold threads directly, but queue heads. This means that once you have located a queue in the hash bucket, you no longer have to walk the rest of the hash chain looking for threads. Instead, you have a list of all the threads sleeping on that wait channel. - Outside of the sleepq code and the sleep/cv code the kernel no longer differentiates between cv's and sleep/wakeup. For example, calls to abortsleep() and cv_abort() are replaced with a call to sleepq_abort(). Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and cv_waitq_remove() have been replaced with calls to sleepq_remove(). - The sched_sleep() function no longer accepts a priority argument as sleep's no longer inherently bump the priority. Instead, this is soley a propery of msleep() which explicitly calls sched_prio() before blocking. - The TDF_ONSLEEPQ flag has been dropped as it was never used. The associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been dropped and replaced with a single explicit clearing of td_wchan. TD_SET_ONSLEEPQ() would really have only made sense if it had taken the wait channel and message as arguments anyway. Now that that only happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
if (td->td_priority > PUSER)
td->td_priority = PUSER;
}
Switch the sleep/wakeup and condition variable implementations to use the sleep queue interface: - Sleep queues attempt to merge some of the benefits of both sleep queues and condition variables. Having sleep qeueus in a hash table avoids having to allocate a queue head for each wait channel. Thus, struct cv has shrunk down to just a single char * pointer now. However, the hash table does not hold threads directly, but queue heads. This means that once you have located a queue in the hash bucket, you no longer have to walk the rest of the hash chain looking for threads. Instead, you have a list of all the threads sleeping on that wait channel. - Outside of the sleepq code and the sleep/cv code the kernel no longer differentiates between cv's and sleep/wakeup. For example, calls to abortsleep() and cv_abort() are replaced with a call to sleepq_abort(). Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and cv_waitq_remove() have been replaced with calls to sleepq_remove(). - The sched_sleep() function no longer accepts a priority argument as sleep's no longer inherently bump the priority. Instead, this is soley a propery of msleep() which explicitly calls sched_prio() before blocking. - The TDF_ONSLEEPQ flag has been dropped as it was never used. The associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been dropped and replaced with a single explicit clearing of td_wchan. TD_SET_ONSLEEPQ() would really have only made sense if it had taken the wait channel and message as arguments anyway. Now that that only happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
sleepq_abort(td);
}
#ifdef SMP
else {
1994-05-24 10:09:53 +00:00
/*
* Other states do nothing with the signal immediatly,
1994-05-24 10:09:53 +00:00
* other than kicking ourselves if we are running.
* It will either never be noticed, or noticed very soon.
*/
Switch the sleep/wakeup and condition variable implementations to use the sleep queue interface: - Sleep queues attempt to merge some of the benefits of both sleep queues and condition variables. Having sleep qeueus in a hash table avoids having to allocate a queue head for each wait channel. Thus, struct cv has shrunk down to just a single char * pointer now. However, the hash table does not hold threads directly, but queue heads. This means that once you have located a queue in the hash bucket, you no longer have to walk the rest of the hash chain looking for threads. Instead, you have a list of all the threads sleeping on that wait channel. - Outside of the sleepq code and the sleep/cv code the kernel no longer differentiates between cv's and sleep/wakeup. For example, calls to abortsleep() and cv_abort() are replaced with a call to sleepq_abort(). Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and cv_waitq_remove() have been replaced with calls to sleepq_remove(). - The sched_sleep() function no longer accepts a priority argument as sleep's no longer inherently bump the priority. Instead, this is soley a propery of msleep() which explicitly calls sched_prio() before blocking. - The TDF_ONSLEEPQ flag has been dropped as it was never used. The associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been dropped and replaced with a single explicit clearing of td_wchan. TD_SET_ONSLEEPQ() would really have only made sense if it had taken the wait channel and message as arguments anyway. Now that that only happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
if (TD_IS_RUNNING(td) && td != curthread)
forward_signal(td);
}
#endif
1994-05-24 10:09:53 +00:00
}
void
ptracestop(struct thread *td, int sig)
{
struct proc *p = td->td_proc;
PROC_LOCK_ASSERT(p, MA_OWNED);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
&p->p_mtx.mtx_object, "Stopping for traced signal");
p->p_xstat = sig;
PROC_LOCK(p->p_pptr);
psignal(p->p_pptr, SIGCHLD);
PROC_UNLOCK(p->p_pptr);
stop(p);
mtx_lock_spin(&sched_lock);
thread_suspend_one(td);
PROC_UNLOCK(p);
DROP_GIANT();
mi_switch(SW_INVOL);
mtx_unlock_spin(&sched_lock);
PICKUP_GIANT();
}
1994-05-24 10:09:53 +00:00
/*
* If the current process has received a signal (should be caught or cause
* termination, should interrupt current syscall), return the signal number.
* Stop signals with default action are processed immediately, then cleared;
* they aren't returned. This is checked after each entry to the system for
* a syscall or trap (though this can usually be done without calling issignal
* by checking the pending signal masks in cursig.) The normal call
1994-05-24 10:09:53 +00:00
* sequence is
*
* while (sig = cursig(curthread))
* postsig(sig);
1994-05-24 10:09:53 +00:00
*/
static int
issignal(td)
struct thread *td;
1994-05-24 10:09:53 +00:00
{
struct proc *p;
struct sigacts *ps;
sigset_t sigpending;
int sig, prop;
struct thread *td0;
1994-05-24 10:09:53 +00:00
p = td->td_proc;
ps = p->p_sigacts;
mtx_assert(&ps->ps_mtx, MA_OWNED);
PROC_LOCK_ASSERT(p, MA_OWNED);
1994-05-24 10:09:53 +00:00
for (;;) {
int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
sigpending = td->td_siglist;
SIGSETNAND(sigpending, td->td_sigmask);
1994-05-24 10:09:53 +00:00
if (p->p_flag & P_PPWAIT)
SIG_STOPSIGMASK(sigpending);
if (SIGISEMPTY(sigpending)) /* no signal to send */
1994-05-24 10:09:53 +00:00
return (0);
sig = sig_ffs(&sigpending);
if (p->p_stops & S_SIG) {
mtx_unlock(&ps->ps_mtx);
stopevent(p, S_SIG, sig);
mtx_lock(&ps->ps_mtx);
}
1994-05-24 10:09:53 +00:00
/*
* We should see pending but ignored signals
* only if P_TRACED was on when they were posted.
*/
if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) {
SIGDELSET(td->td_siglist, sig);
1994-05-24 10:09:53 +00:00
continue;
}
if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
/*
* If traced, always stop.
1994-05-24 10:09:53 +00:00
*/
mtx_unlock(&ps->ps_mtx);
ptracestop(td, sig);
PROC_LOCK(p);
mtx_lock(&ps->ps_mtx);
1994-05-24 10:09:53 +00:00
/*
* If parent wants us to take the signal,
* then it will leave it in p->p_xstat;
* otherwise we just look for signals again.
*/
SIGDELSET(td->td_siglist, sig); /* clear old signal */
sig = p->p_xstat;
if (sig == 0)
1994-05-24 10:09:53 +00:00
continue;
/*
* If the traced bit got turned off, go back up
* to the top to rescan signals. This ensures
* that p_sig* and p_sigact are consistent.
*/
if ((p->p_flag & P_TRACED) == 0)
continue;
1994-05-24 10:09:53 +00:00
/*
* Put the new signal into td_siglist. If the
* signal is being masked, look for other signals.
1994-05-24 10:09:53 +00:00
*/
SIGADDSET(td->td_siglist, sig);
if (SIGISMEMBER(td->td_sigmask, sig))
1994-05-24 10:09:53 +00:00
continue;
signotify(td);
1994-05-24 10:09:53 +00:00
}
prop = sigprop(sig);
1994-05-24 10:09:53 +00:00
/*
* Decide whether the signal should be returned.
* Return the signal's number, or fall through
* to clear it from the pending mask.
*/
switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1994-05-24 10:09:53 +00:00
case (intptr_t)SIG_DFL:
1994-05-24 10:09:53 +00:00
/*
* Don't take default actions on system processes.
*/
if (p->p_pid <= 1) {
#ifdef DIAGNOSTIC
/*
* Are you sure you want to ignore SIGSEGV
* in init? XXX
*/
printf("Process (pid %lu) got signal %d\n",
(u_long)p->p_pid, sig);
1994-05-24 10:09:53 +00:00
#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))
1994-05-24 10:09:53 +00:00
break; /* == ignore */
mtx_unlock(&ps->ps_mtx);
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK,
&p->p_mtx.mtx_object, "Catching SIGSTOP");
p->p_flag |= P_STOPPED_SIG;
p->p_xstat = sig;
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td0) {
if (TD_IS_SLEEPING(td0) &&
(td0->td_flags & TDF_SINTR) &&
!TD_IS_SUSPENDED(td0)) {
thread_suspend_one(td0);
} else if (td != td0) {
td0->td_flags |= TDF_ASTPENDING;
}
}
thread_stopped(p);
thread_suspend_one(td);
PROC_UNLOCK(p);
DROP_GIANT();
mi_switch(SW_INVOL);
mtx_unlock_spin(&sched_lock);
PICKUP_GIANT();
PROC_LOCK(p);
mtx_lock(&ps->ps_mtx);
1994-05-24 10:09:53 +00:00
break;
} else if (prop & SA_IGNORE) {
1994-05-24 10:09:53 +00:00
/*
* Except for SIGCONT, shouldn't get here.
* Default action is to ignore; drop it.
*/
break; /* == ignore */
} else
return (sig);
1994-05-24 10:09:53 +00:00
/*NOTREACHED*/
case (intptr_t)SIG_IGN:
1994-05-24 10:09:53 +00:00
/*
* Masking above should prevent us ever trying
* to take action on an ignored signal other
* than SIGCONT, unless process is traced.
*/
if ((prop & SA_CONT) == 0 &&
(p->p_flag & P_TRACED) == 0)
printf("issignal\n");
break; /* == ignore */
default:
/*
* This signal has an action, let
* postsig() process it.
*/
return (sig);
1994-05-24 10:09:53 +00:00
}
SIGDELSET(td->td_siglist, sig); /* take the signal! */
1994-05-24 10:09:53 +00:00
}
/* NOTREACHED */
}
/*
* Put the argument process into the stopped state and notify the parent
* via wakeup. Signals are handled elsewhere. The process must not be
* on the run queue. Must be called with the proc p locked.
1994-05-24 10:09:53 +00:00
*/
static void
stop(struct proc *p)
1994-05-24 10:09:53 +00:00
{
PROC_LOCK_ASSERT(p, MA_OWNED);
p->p_flag |= P_STOPPED_SIG;
1994-05-24 10:09:53 +00:00
p->p_flag &= ~P_WAITED;
2002-06-29 02:00:02 +00:00
wakeup(p->p_pptr);
1994-05-24 10:09:53 +00:00
}
/*
* MPSAFE
*/
void
thread_stopped(struct proc *p)
{
struct proc *p1 = curthread->td_proc;
struct sigacts *ps;
int n;
PROC_LOCK_ASSERT(p, MA_OWNED);
mtx_assert(&sched_lock, MA_OWNED);
n = p->p_suspcount;
if (p == p1)
n++;
if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) {
mtx_unlock_spin(&sched_lock);
stop(p);
PROC_LOCK(p->p_pptr);
ps = p->p_pptr->p_sigacts;
mtx_lock(&ps->ps_mtx);
if ((ps->ps_flag & PS_NOCLDSTOP) == 0) {
mtx_unlock(&ps->ps_mtx);
psignal(p->p_pptr, SIGCHLD);
} else
mtx_unlock(&ps->ps_mtx);
PROC_UNLOCK(p->p_pptr);
mtx_lock_spin(&sched_lock);
}
}
1994-05-24 10:09:53 +00:00
/*
* Take the action for the specified signal
* from the current set of pending signals.
*/
void
postsig(sig)
register int sig;
1994-05-24 10:09:53 +00:00
{
struct thread *td = curthread;
register struct proc *p = td->td_proc;
struct sigacts *ps;
sig_t action;
sigset_t returnmask;
int code;
1994-05-24 10:09:53 +00:00
KASSERT(sig != 0, ("postsig"));
PROC_LOCK_ASSERT(p, MA_OWNED);
ps = p->p_sigacts;
mtx_assert(&ps->ps_mtx, MA_OWNED);
SIGDELSET(td->td_siglist, sig);
action = ps->ps_sigact[_SIG_IDX(sig)];
1994-05-24 10:09:53 +00:00
#ifdef KTRACE
if (KTRPOINT(td, KTR_PSIG))
ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ?
&td->td_oldsigmask : &td->td_sigmask, 0);
1994-05-24 10:09:53 +00:00
#endif
if (p->p_stops & S_SIG) {
mtx_unlock(&ps->ps_mtx);
stopevent(p, S_SIG, sig);
mtx_lock(&ps->ps_mtx);
}
if (!(td->td_flags & TDF_SA && td->td_mailbox) &&
action == SIG_DFL) {
1994-05-24 10:09:53 +00:00
/*
* Default action, where the default is to kill
* the process. (Other cases were ignored above.)
*/
mtx_unlock(&ps->ps_mtx);
sigexit(td, sig);
1994-05-24 10:09:53 +00:00
/* NOTREACHED */
} else {
if (td->td_flags & TDF_SA && td->td_mailbox) {
if (sig == SIGKILL) {
mtx_unlock(&ps->ps_mtx);
sigexit(td, sig);
}
}
1994-05-24 10:09:53 +00:00
/*
* If we get here, the signal must be caught.
*/
KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
1999-01-10 01:58:29 +00:00
("postsig action"));
1994-05-24 10:09:53 +00:00
/*
* Set the new mask value and also defer further
* occurrences of this signal.
1994-05-24 10:09:53 +00:00
*
* Special case: user has done a sigsuspend. Here the
1994-05-24 10:09:53 +00:00
* current mask is not of interest, but rather the
* mask from before the sigsuspend is what we want
1994-05-24 10:09:53 +00:00
* restored after the signal processing is completed.
*/
if (td->td_pflags & TDP_OLDMASK) {
returnmask = td->td_oldsigmask;
td->td_pflags &= ~TDP_OLDMASK;
1994-05-24 10:09:53 +00:00
} else
returnmask = td->td_sigmask;
SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
if (!SIGISMEMBER(ps->ps_signodefer, sig))
SIGADDSET(td->td_sigmask, sig);
if (SIGISMEMBER(ps->ps_sigreset, sig)) {
/*
* See kern_sigaction() for origin of this code.
*/
SIGDELSET(ps->ps_sigcatch, sig);
if (sig != SIGCONT &&
sigprop(sig) & SA_IGNORE)
SIGADDSET(ps->ps_sigignore, sig);
ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
}
1994-05-24 10:09:53 +00:00
p->p_stats->p_ru.ru_nsignals++;
if (p->p_sig != sig) {
1994-05-24 10:09:53 +00:00
code = 0;
} else {
code = p->p_code;
p->p_code = 0;
p->p_sig = 0;
1994-05-24 10:09:53 +00:00
}
if (td->td_flags & TDF_SA && td->td_mailbox)
thread_signal_add(curthread, sig);
else
(*p->p_sysent->sv_sendsig)(action, sig,
&returnmask, code);
1994-05-24 10:09:53 +00:00
}
}
/*
* Kill the current process for stated reason.
*/
void
1994-05-24 10:09:53 +00:00
killproc(p, why)
struct proc *p;
char *why;
{
PROC_LOCK_ASSERT(p, MA_OWNED);
CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)",
p, p->p_pid, p->p_comm);
log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm,
o Merge contents of struct pcred into struct ucred. Specifically, add the real uid, saved uid, real gid, and saved gid to ucred, as well as the pcred->pc_uidinfo, which was associated with the real uid, only rename it to cr_ruidinfo so as not to conflict with cr_uidinfo, which corresponds to the effective uid. o Remove p_cred from struct proc; add p_ucred to struct proc, replacing original macro that pointed. p->p_ucred to p->p_cred->pc_ucred. o Universally update code so that it makes use of ucred instead of pcred, p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo, cr_{r,sv}{u,g}id instead of p_*, etc. o Remove pcred0 and its initialization from init_main.c; initialize cr_ruidinfo there. o Restruction many credential modification chunks to always crdup while we figure out locking and optimizations; generally speaking, this means moving to a structure like this: newcred = crdup(oldcred); ... p->p_ucred = newcred; crfree(oldcred); It's not race-free, but better than nothing. There are also races in sys_process.c, all inter-process authorization, fork, exec, and exit. o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid; remove comments indicating that the old arrangement was a problem. o Restructure exec1() a little to use newcred/oldcred arrangement, and use improved uid management primitives. o Clean up exit1() so as to do less work in credential cleanup due to pcred removal. o Clean up fork1() so as to do less work in credential cleanup and allocation. o Clean up ktrcanset() to take into account changes, and move to using suser_xxx() instead of performing a direct uid==0 comparision. o Improve commenting in various kern_prot.c credential modification calls to better document current behavior. In a couple of places, current behavior is a little questionable and we need to check POSIX.1 to make sure it's "right". More commenting work still remains to be done. o Update credential management calls, such as crfree(), to take into account new ruidinfo reference. o Modify or add the following uid and gid helper routines: change_euid() change_egid() change_ruid() change_rgid() change_svuid() change_svgid() In each case, the call now acts on a credential not a process, and as such no longer requires more complicated process locking/etc. They now assume the caller will do any necessary allocation of an exclusive credential reference. Each is commented to document its reference requirements. o CANSIGIO() is simplified to require only credentials, not processes and pcreds. o Remove lots of (p_pcred==NULL) checks. o Add an XXX to authorization code in nfs_lock.c, since it's questionable, and needs to be considered carefully. o Simplify posix4 authorization code to require only credentials, not processes and pcreds. Note that this authorization, as well as CANSIGIO(), needs to be updated to use the p_cansignal() and p_cansched() centralized authorization routines, as they currently do not take into account some desirable restrictions that are handled by the centralized routines, as well as being inconsistent with other similar authorization instances. o Update libkvm to take these changes into account. Obtained from: TrustedBSD Project Reviewed by: green, bde, jhb, freebsd-arch, freebsd-audit
2001-05-25 16:59:11 +00:00
p->p_ucred ? p->p_ucred->cr_uid : -1, why);
1994-05-24 10:09:53 +00:00
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.
*
* MPSAFE
1994-05-24 10:09:53 +00:00
*/
void
sigexit(td, sig)
struct thread *td;
int sig;
1994-05-24 10:09:53 +00:00
{
struct proc *p = td->td_proc;
1994-05-24 10:09:53 +00:00
PROC_LOCK_ASSERT(p, MA_OWNED);
1994-05-24 10:09:53 +00:00
p->p_acflag |= AXSIG;
if (sigprop(sig) & SA_CORE) {
p->p_sig = sig;
/*
* Log signals which would cause core dumps
1995-05-30 08:16:23 +00:00
* (Log as LOG_INFO to appease those who don't want
* these messages.)
* XXX : Todo, as well as euid, write out ruid too
* Note that coredump() drops proc lock.
*/
if (coredump(td) == 0)
sig |= WCOREFLAG;
if (kern_logsigexit)
log(LOG_INFO,
"pid %d (%s), uid %d: exited on signal %d%s\n",
p->p_pid, p->p_comm,
td->td_ucred ? td->td_ucred->cr_uid : -1,
sig &~ WCOREFLAG,
sig & WCOREFLAG ? " (core dumped)" : "");
} else
PROC_UNLOCK(p);
exit1(td, W_EXITCODE(0, sig));
1994-05-24 10:09:53 +00:00
/* NOTREACHED */
}
static char corefilename[MAXPATHLEN+1] = {"%N.core"};
SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
sizeof(corefilename), "process corefile name format string");
/*
* expand_name(name, uid, pid)
* Expand the name described in corefilename, using name, uid, and pid.
* corefilename is a printf-like string, with three format specifiers:
* %N name of process ("name")
* %P process id (pid)
* %U user id (uid)
* For example, "%N.core" is the default; they can be disabled completely
* by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P".
* This is controlled by the sysctl variable kern.corefile (see above).
*/
static char *
expand_name(name, uid, pid)
const char *name;
uid_t uid;
pid_t pid;
{
const char *format, *appendstr;
char *temp;
char buf[11]; /* Buffer for pid/uid -- max 4B */
size_t i, l, n;
format = corefilename;
temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO);
if (temp == NULL)
return (NULL);
for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
switch (format[i]) {
case '%': /* Format character */
i++;
switch (format[i]) {
case '%':
appendstr = "%";
break;
case 'N': /* process name */
appendstr = name;
break;
case 'P': /* process id */
sprintf(buf, "%u", pid);
appendstr = buf;
break;
case 'U': /* user id */
sprintf(buf, "%u", uid);
appendstr = buf;
break;
default:
appendstr = "";
log(LOG_ERR,
"Unknown format character %c in `%s'\n",
format[i], format);
}
l = strlen(appendstr);
if ((n + l) >= MAXPATHLEN)
goto toolong;
memcpy(temp + n, appendstr, l);
n += l;
break;
default:
temp[n++] = format[i];
}
}
if (format[i] != '\0')
goto toolong;
return (temp);
toolong:
log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n",
(long)pid, name, (u_long)uid);
free(temp, M_TEMP);
return (NULL);
}
/*
* Dump a process' core. The main routine does some
* policy checking, and creates the name of the coredump;
* then it passes on a vnode and a size limit to the process-specific
* coredump routine if there is one; if there _is not_ one, it returns
* ENOSYS; otherwise it returns the error from the process-specific routine.
*/
static int
coredump(struct thread *td)
{
struct proc *p = td->td_proc;
register struct vnode *vp;
register struct ucred *cred = td->td_ucred;
struct flock lf;
struct nameidata nd;
struct vattr vattr;
int error, error1, flags, locked;
struct mount *mp;
char *name; /* name of corefile */
off_t limit;
PROC_LOCK_ASSERT(p, MA_OWNED);
_STOPEVENT(p, S_CORE, 0);
if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
PROC_UNLOCK(p);
return (EFAULT);
}
/*
* Note that the bulk of limit checking is done after
* the corefile is created. The exception is if the limit
* for corefiles is 0, in which case we don't bother
* creating the corefile at all. This layout means that
* a corefile is truncated instead of not being created,
* if it is larger than the limit.
*/
Locking for the per-process resource limits structure. - struct plimit includes a mutex to protect a reference count. The plimit structure is treated similarly to struct ucred in that is is always copy on write, so having a reference to a structure is sufficient to read from it without needing a further lock. - The proc lock protects the p_limit pointer and must be held while reading limits from a process to keep the limit structure from changing out from under you while reading from it. - Various global limits that are ints are not protected by a lock since int writes are atomic on all the archs we support and thus a lock wouldn't buy us anything. - All accesses to individual resource limits from a process are abstracted behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return either an rlimit, or the current or max individual limit of the specified resource from a process. - dosetrlimit() was renamed to kern_setrlimit() to match existing style of other similar syscall helper functions. - The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit() (it didn't used the stackgap when it should have) but uses lim_rlimit() and kern_setrlimit() instead. - The svr4 compat no longer uses the stackgap for resource limits calls, but uses lim_rlimit() and kern_setrlimit() instead. - The ibcs2 compat no longer uses the stackgap for resource limits. It also no longer uses the stackgap for accessing sysctl's for the ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result, ibcs2_sysconf() no longer needs Giant. - The p_rlimit macro no longer exists. Submitted by: mtm (mostly, I only did a few cleanups and catchups) Tested on: i386 Compiled on: alpha, amd64
2004-02-04 21:52:57 +00:00
limit = (off_t)lim_cur(p, RLIMIT_CORE);
PROC_UNLOCK(p);
Locking for the per-process resource limits structure. - struct plimit includes a mutex to protect a reference count. The plimit structure is treated similarly to struct ucred in that is is always copy on write, so having a reference to a structure is sufficient to read from it without needing a further lock. - The proc lock protects the p_limit pointer and must be held while reading limits from a process to keep the limit structure from changing out from under you while reading from it. - Various global limits that are ints are not protected by a lock since int writes are atomic on all the archs we support and thus a lock wouldn't buy us anything. - All accesses to individual resource limits from a process are abstracted behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return either an rlimit, or the current or max individual limit of the specified resource from a process. - dosetrlimit() was renamed to kern_setrlimit() to match existing style of other similar syscall helper functions. - The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit() (it didn't used the stackgap when it should have) but uses lim_rlimit() and kern_setrlimit() instead. - The svr4 compat no longer uses the stackgap for resource limits calls, but uses lim_rlimit() and kern_setrlimit() instead. - The ibcs2 compat no longer uses the stackgap for resource limits. It also no longer uses the stackgap for accessing sysctl's for the ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result, ibcs2_sysconf() no longer needs Giant. - The p_rlimit macro no longer exists. Submitted by: mtm (mostly, I only did a few cleanups and catchups) Tested on: i386 Compiled on: alpha, amd64
2004-02-04 21:52:57 +00:00
if (limit == 0)
return (EFBIG);
mtx_lock(&Giant);
restart:
name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
if (name == NULL) {
mtx_unlock(&Giant);
return (EINVAL);
}
NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */
flags = O_CREAT | FWRITE | O_NOFOLLOW;
error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1);
free(name, M_TEMP);
if (error) {
mtx_unlock(&Giant);
return (error);
}
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
/* Don't dump to non-regular files or files with links. */
if (vp->v_type != VREG ||
VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) {
VOP_UNLOCK(vp, 0, td);
error = EFAULT;
goto out;
}
VOP_UNLOCK(vp, 0, td);
lf.l_whence = SEEK_SET;
lf.l_start = 0;
lf.l_len = 0;
lf.l_type = F_WRLCK;
locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0);
if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
lf.l_type = F_UNLCK;
if (locked)
VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
return (error);
if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
return (error);
goto restart;
}
VATTR_NULL(&vattr);
vattr.va_size = 0;
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
VOP_LEASE(vp, td, cred, LEASE_WRITE);
VOP_SETATTR(vp, &vattr, cred, td);
VOP_UNLOCK(vp, 0, td);
PROC_LOCK(p);
p->p_acflag |= ACORE;
PROC_UNLOCK(p);
error = p->p_sysent->sv_coredump ?
p->p_sysent->sv_coredump(td, vp, limit) :
ENOSYS;
if (locked) {
lf.l_type = F_UNLCK;
VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
}
vn_finished_write(mp);
out:
error1 = vn_close(vp, FWRITE, cred, td);
mtx_unlock(&Giant);
if (error == 0)
error = error1;
return (error);
}
1994-05-24 10:09:53 +00:00
/*
* Nonexistent system call-- signal process (may want to handle it).
* Flag error in case process won't see signal immediately (blocked or ignored).
*/
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
struct nosys_args {
int dummy;
};
#endif
/*
* MPSAFE
*/
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
nosys(td, args)
struct thread *td;
1994-05-24 10:09:53 +00:00
struct nosys_args *args;
{
struct proc *p = td->td_proc;
PROC_LOCK(p);
1994-05-24 10:09:53 +00:00
psignal(p, SIGSYS);
PROC_UNLOCK(p);
return (ENOSYS);
1994-05-24 10:09:53 +00:00
}
/*
* Send a SIGIO or SIGURG signal to a process or process group using
* stored credentials rather than those of the current process.
*/
void
pgsigio(sigiop, sig, checkctty)
struct sigio **sigiop;
int sig, checkctty;
{
struct sigio *sigio;
SIGIO_LOCK();
sigio = *sigiop;
if (sigio == NULL) {
SIGIO_UNLOCK();
return;
}
if (sigio->sio_pgid > 0) {
PROC_LOCK(sigio->sio_proc);
if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
psignal(sigio->sio_proc, sig);
PROC_UNLOCK(sigio->sio_proc);
} else if (sigio->sio_pgid < 0) {
struct proc *p;
PGRP_LOCK(sigio->sio_pgrp);
LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) {
PROC_LOCK(p);
if (CANSIGIO(sigio->sio_ucred, p->p_ucred) &&
(checkctty == 0 || (p->p_flag & P_CONTROLT)))
psignal(p, sig);
PROC_UNLOCK(p);
}
PGRP_UNLOCK(sigio->sio_pgrp);
}
SIGIO_UNLOCK();
}
static int
filt_sigattach(struct knote *kn)
{
struct proc *p = curproc;
kn->kn_ptr.p_proc = p;
kn->kn_flags |= EV_CLEAR; /* automatically set */
PROC_LOCK(p);
SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
PROC_UNLOCK(p);
return (0);
}
static void
filt_sigdetach(struct knote *kn)
{
struct proc *p = kn->kn_ptr.p_proc;
PROC_LOCK(p);
SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
PROC_UNLOCK(p);
}
/*
* signal knotes are shared with proc knotes, so we apply a mask to
* the hint in order to differentiate them from process hints. This
* could be avoided by using a signal-specific knote list, but probably
* isn't worth the trouble.
*/
static int
filt_signal(struct knote *kn, long hint)
{
if (hint & NOTE_SIGNAL) {
hint &= ~NOTE_SIGNAL;
if (kn->kn_id == hint)
kn->kn_data++;
}
return (kn->kn_data != 0);
}
struct sigacts *
sigacts_alloc(void)
{
struct sigacts *ps;
ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO);
ps->ps_refcnt = 1;
mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF);
return (ps);
}
void
sigacts_free(struct sigacts *ps)
{
mtx_lock(&ps->ps_mtx);
ps->ps_refcnt--;
if (ps->ps_refcnt == 0) {
mtx_destroy(&ps->ps_mtx);
free(ps, M_SUBPROC);
} else
mtx_unlock(&ps->ps_mtx);
}
struct sigacts *
sigacts_hold(struct sigacts *ps)
{
mtx_lock(&ps->ps_mtx);
ps->ps_refcnt++;
mtx_unlock(&ps->ps_mtx);
return (ps);
}
void
sigacts_copy(struct sigacts *dest, struct sigacts *src)
{
KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest"));
mtx_lock(&src->ps_mtx);
bcopy(src, dest, offsetof(struct sigacts, ps_refcnt));
mtx_unlock(&src->ps_mtx);
}
int
sigacts_shared(struct sigacts *ps)
{
int shared;
mtx_lock(&ps->ps_mtx);
shared = ps->ps_refcnt > 1;
mtx_unlock(&ps->ps_mtx);
return (shared);
}