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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_sig.c 8.7 (Berkeley) 4/18/94
1999-08-28 01:08:13 +00:00
* $FreeBSD$
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*/
#include "opt_compat.h"
#include "opt_ktrace.h"
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#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
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#include <sys/signalvar.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/event.h>
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#include <sys/proc.h>
#include <sys/pioctl.h>
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#include <sys/acct.h>
#include <sys/fcntl.h>
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#include <sys/condvar.h>
#include <sys/lock.h>
#include <sys/mutex.h>
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#include <sys/wait.h>
#include <sys/ktr.h>
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#include <sys/ktrace.h>
#include <sys/resourcevar.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/syslog.h>
Mega-commit for Linux emulator update.. This has been stress tested under netscape-2.0 for Linux running all the Java stuff. The scrollbars are now working, at least on my machine. (whew! :-) I'm uncomfortable with the size of this commit, but it's too inter-dependant to easily seperate out. The main changes: COMPAT_LINUX is *GONE*. Most of the code has been moved out of the i386 machine dependent section into the linux emulator itself. The int 0x80 syscall code was almost identical to the lcall 7,0 code and a minor tweak allows them to both be used with the same C code. All kernels can now just modload the lkm and it'll DTRT without having to rebuild the kernel first. Like IBCS2, you can statically compile it in with "options LINUX". A pile of new syscalls implemented, including getdents(), llseek(), readv(), writev(), msync(), personality(). The Linux-ELF libraries want to use some of these. linux_select() now obeys Linux semantics, ie: returns the time remaining of the timeout value rather than leaving it the original value. Quite a few bugs removed, including incorrect arguments being used in syscalls.. eg: mixups between passing the sigset as an int, vs passing it as a pointer and doing a copyin(), missing return values, unhandled cases, SIOC* ioctls, etc. The build for the code has changed. i386/conf/files now knows how to build linux_genassym and generate linux_assym.h on the fly. Supporting changes elsewhere in the kernel: The user-mode signal trampoline has moved from the U area to immediately below the top of the stack (below PS_STRINGS). This allows the different binary emulations to have their own signal trampoline code (which gets rid of the hardwired syscall 103 (sigreturn on BSD, syslog on Linux)) and so that the emulator can provide the exact "struct sigcontext *" argument to the program's signal handlers. The sigstack's "ss_flags" now uses SS_DISABLE and SS_ONSTACK flags, which have the same values as the re-used SA_DISABLE and SA_ONSTACK which are intended for sigaction only. This enables the support of a SA_RESETHAND flag to sigaction to implement the gross SYSV and Linux SA_ONESHOT signal semantics where the signal handler is reset when it's triggered. makesyscalls.sh no longer appends the struct sysentvec on the end of the generated init_sysent.c code. It's a lot saner to have it in a seperate file rather than trying to update the structure inside the awk script. :-) At exec time, the dozen bytes or so of signal trampoline code are copied to the top of the user's stack, rather than obtaining the trampoline code the old way by getting a clone of the parent's user area. This allows Linux and native binaries to freely exec each other without getting trampolines mixed up.
1996-03-02 19:38:20 +00:00
#include <sys/sysent.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/unistd.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 int do_sigprocmask(struct proc *p, int how, sigset_t *set,
sigset_t *oset, int old);
static char *expand_name(const char *, uid_t, pid_t);
static int killpg1(struct thread *td, int sig, int pgid, int all);
static int sig_ffs(sigset_t *set);
static int sigprop(int sig);
static void stop(struct proc *);
static void tdsignal(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);
struct filterops sig_filtops =
{ 0, filt_sigattach, filt_sigdetach, filt_signal };
static int kern_logsigexit = 1;
SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW,
&kern_logsigexit, 0,
"Log processes quitting on abnormal signals to syslog(3)");
/*
* Policy -- Can ucred cr1 send SIGIO to process cr2?
* Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG
* in the right situations.
*/
#define CANSIGIO(cr1, cr2) \
((cr1)->cr_uid == 0 || \
(cr1)->cr_ruid == (cr2)->cr_ruid || \
(cr1)->cr_uid == (cr2)->cr_ruid || \
(cr1)->cr_ruid == (cr2)->cr_uid || \
(cr1)->cr_uid == (cr2)->cr_uid)
int sugid_coredump;
SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW,
&sugid_coredump, 0, "Enable coredumping set user/group ID processes");
static int do_coredump = 1;
SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW,
&do_coredump, 0, "Enable/Disable coredumps");
/*
* Signal properties and actions.
* The array below categorizes the signals and their default actions
* according to the following properties:
*/
#define SA_KILL 0x01 /* terminates process by default */
#define SA_CORE 0x02 /* ditto and coredumps */
#define SA_STOP 0x04 /* suspend process */
#define SA_TTYSTOP 0x08 /* ditto, from tty */
#define SA_IGNORE 0x10 /* ignore by default */
#define SA_CONT 0x20 /* continue if suspended */
#define SA_CANTMASK 0x40 /* non-maskable, catchable */
static int sigproptbl[NSIG] = {
SA_KILL, /* SIGHUP */
SA_KILL, /* SIGINT */
SA_KILL|SA_CORE, /* SIGQUIT */
SA_KILL|SA_CORE, /* SIGILL */
SA_KILL|SA_CORE, /* SIGTRAP */
SA_KILL|SA_CORE, /* SIGABRT */
SA_KILL|SA_CORE, /* SIGEMT */
SA_KILL|SA_CORE, /* SIGFPE */
SA_KILL, /* SIGKILL */
SA_KILL|SA_CORE, /* SIGBUS */
SA_KILL|SA_CORE, /* SIGSEGV */
SA_KILL|SA_CORE, /* SIGSYS */
SA_KILL, /* SIGPIPE */
SA_KILL, /* SIGALRM */
SA_KILL, /* SIGTERM */
SA_IGNORE, /* SIGURG */
SA_STOP, /* SIGSTOP */
SA_STOP|SA_TTYSTOP, /* SIGTSTP */
SA_IGNORE|SA_CONT, /* SIGCONT */
SA_IGNORE, /* SIGCHLD */
SA_STOP|SA_TTYSTOP, /* SIGTTIN */
SA_STOP|SA_TTYSTOP, /* SIGTTOU */
SA_IGNORE, /* SIGIO */
SA_KILL, /* SIGXCPU */
SA_KILL, /* SIGXFSZ */
SA_KILL, /* SIGVTALRM */
SA_KILL, /* SIGPROF */
SA_IGNORE, /* SIGWINCH */
SA_IGNORE, /* SIGINFO */
SA_KILL, /* SIGUSR1 */
SA_KILL, /* SIGUSR2 */
};
/*
* Determine signal that should be delivered to process p, the current
* process, 0 if none. If there is a pending stop signal with default
* action, the process stops in issignal().
* XXXKSE the check for a pending stop is not done under KSE
*
* MP SAFE.
*/
int
cursig(struct thread *td)
{
struct proc *p = td->td_proc;
PROC_LOCK_ASSERT(p, MA_OWNED);
mtx_assert(&sched_lock, MA_NOTOWNED);
return (SIGPENDING(p) ? 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 p_siglist or
* unmasked in p_sigmask.
*/
void
signotify(struct proc *p)
{
struct kse *ke;
struct ksegrp *kg;
PROC_LOCK_ASSERT(p, MA_OWNED);
mtx_lock_spin(&sched_lock);
if (SIGPENDING(p)) {
p->p_sflag |= PS_NEEDSIGCHK;
/* XXXKSE for now punish all KSEs */
FOREACH_KSEGRP_IN_PROC(p, kg) {
FOREACH_KSE_IN_GROUP(kg, ke) {
ke->ke_flags |= KEF_ASTPENDING;
}
}
}
mtx_unlock_spin(&sched_lock);
}
static __inline int
sigprop(int sig)
{
if (sig > 0 && sig < NSIG)
return (sigproptbl[_SIG_IDX(sig)]);
return (0);
}
static __inline int
sig_ffs(sigset_t *set)
{
int i;
for (i = 0; i < _SIG_WORDS; i++)
if (set->__bits[i])
return (ffs(set->__bits[i]) + (i * 32));
return (0);
}
/*
* kern_sigaction
* sigaction
* freebsd4_sigaction
* osigaction
*/
int
kern_sigaction(td, sig, act, oact, flags)
struct thread *td;
register int sig;
struct sigaction *act, *oact;
int flags;
{
register struct sigacts *ps;
struct proc *p = td->td_proc;
if (!_SIG_VALID(sig))
return (EINVAL);
PROC_LOCK(p);
ps = p->p_sigacts;
if (oact) {
oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)];
oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)];
oact->sa_flags = 0;
if (SIGISMEMBER(ps->ps_sigonstack, sig))
oact->sa_flags |= SA_ONSTACK;
if (!SIGISMEMBER(ps->ps_sigintr, sig))
oact->sa_flags |= SA_RESTART;
if (SIGISMEMBER(ps->ps_sigreset, sig))
oact->sa_flags |= SA_RESETHAND;
if (SIGISMEMBER(ps->ps_signodefer, sig))
oact->sa_flags |= SA_NODEFER;
if (SIGISMEMBER(ps->ps_siginfo, sig))
oact->sa_flags |= SA_SIGINFO;
if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDSTOP)
oact->sa_flags |= SA_NOCLDSTOP;
if (sig == SIGCHLD && p->p_procsig->ps_flag & PS_NOCLDWAIT)
oact->sa_flags |= SA_NOCLDWAIT;
}
if (act) {
if ((sig == SIGKILL || sig == SIGSTOP) &&
act->sa_handler != SIG_DFL) {
PROC_UNLOCK(p);
return (EINVAL);
}
/*
* Change setting atomically.
*/
ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask;
SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]);
if (act->sa_flags & SA_SIGINFO) {
ps->ps_sigact[_SIG_IDX(sig)] =
(__sighandler_t *)act->sa_sigaction;
SIGADDSET(ps->ps_siginfo, sig);
} else {
ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler;
SIGDELSET(ps->ps_siginfo, sig);
}
if (!(act->sa_flags & SA_RESTART))
SIGADDSET(ps->ps_sigintr, sig);
else
SIGDELSET(ps->ps_sigintr, sig);
if (act->sa_flags & SA_ONSTACK)
SIGADDSET(ps->ps_sigonstack, sig);
else
SIGDELSET(ps->ps_sigonstack, sig);
if (act->sa_flags & SA_RESETHAND)
SIGADDSET(ps->ps_sigreset, sig);
else
SIGDELSET(ps->ps_sigreset, sig);
if (act->sa_flags & SA_NODEFER)
SIGADDSET(ps->ps_signodefer, sig);
else
SIGDELSET(ps->ps_signodefer, sig);
#ifdef COMPAT_SUNOS
if (act->sa_flags & SA_USERTRAMP)
SIGADDSET(ps->ps_usertramp, sig);
else
SIGDELSET(ps->ps_usertramp, sig);
#endif
if (sig == SIGCHLD) {
if (act->sa_flags & SA_NOCLDSTOP)
p->p_procsig->ps_flag |= PS_NOCLDSTOP;
else
p->p_procsig->ps_flag &= ~PS_NOCLDSTOP;
if (act->sa_flags & SA_NOCLDWAIT) {
/*
* Paranoia: since SA_NOCLDWAIT is implemented
* by reparenting the dying child to PID 1 (and
* trust it to reap the zombie), PID 1 itself
* is forbidden to set SA_NOCLDWAIT.
*/
if (p->p_pid == 1)
p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
else
p->p_procsig->ps_flag |= PS_NOCLDWAIT;
} else
p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
p->p_procsig->ps_flag |= PS_CLDSIGIGN;
else
p->p_procsig->ps_flag &= ~PS_CLDSIGIGN;
}
/*
* Set bit in p_sigignore for signals that are set to SIG_IGN,
* and for signals set to SIG_DFL where the default is to
* ignore. However, don't put SIGCONT in p_sigignore, as we
* have to restart the process.
*/
if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
(sigprop(sig) & SA_IGNORE &&
ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) {
/* never to be seen again */
SIGDELSET(p->p_siglist, sig);
if (sig != SIGCONT)
/* easier in psignal */
SIGADDSET(p->p_sigignore, sig);
SIGDELSET(p->p_sigcatch, sig);
} else {
SIGDELSET(p->p_sigignore, sig);
if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)
SIGDELSET(p->p_sigcatch, sig);
else
SIGADDSET(p->p_sigcatch, sig);
}
#ifdef COMPAT_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
}
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
*/
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/* ARGSUSED */
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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mtx_lock(&Giant);
actp = (uap->act != NULL) ? &act : NULL;
oactp = (uap->oact != NULL) ? &oact : NULL;
if (actp) {
error = copyin(uap->act, actp, sizeof(act));
if (error)
goto done2;
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}
error = kern_sigaction(td, uap->sig, actp, oactp, 0);
if (oactp && !error) {
error = copyout(oactp, uap->oact, sizeof(oact));
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}
done2:
mtx_unlock(&Giant);
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
*/
/* ARGSUSED */
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;
mtx_lock(&Giant);
actp = (uap->act != NULL) ? &act : NULL;
oactp = (uap->oact != NULL) ? &oact : NULL;
if (actp) {
error = copyin(uap->act, actp, sizeof(act));
if (error)
goto done2;
}
error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4);
if (oactp && !error) {
error = copyout(oactp, uap->oact, sizeof(oact));
}
done2:
mtx_unlock(&Giant);
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
*/
/* ARGSUSED */
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;
mtx_lock(&Giant);
if (nsap) {
error = copyin(uap->nsa, &sa, sizeof(sa));
if (error)
goto done2;
nsap->sa_handler = sa.sa_handler;
nsap->sa_flags = sa.sa_flags;
OSIG2SIG(sa.sa_mask, nsap->sa_mask);
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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}
done2:
mtx_unlock(&Giant);
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;
PROC_LOCK(p);
for (i = 1; i <= NSIG; i++)
if (sigprop(i) & SA_IGNORE && i != SIGCONT)
SIGADDSET(p->p_sigignore, i);
PROC_UNLOCK(p);
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}
/*
* Reset signals for an exec of the specified process.
*/
void
execsigs(p)
register struct proc *p;
{
register struct sigacts *ps;
register int sig;
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/*
* Reset caught signals. Held signals remain held
* through p_sigmask (unless they were caught,
* and are now ignored by default).
*/
PROC_LOCK_ASSERT(p, MA_OWNED);
ps = p->p_sigacts;
while (SIGNOTEMPTY(p->p_sigcatch)) {
sig = sig_ffs(&p->p_sigcatch);
SIGDELSET(p->p_sigcatch, sig);
if (sigprop(sig) & SA_IGNORE) {
if (sig != SIGCONT)
SIGADDSET(p->p_sigignore, sig);
SIGDELSET(p->p_siglist, sig);
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.
*/
p->p_sigstk.ss_flags = SS_DISABLE;
p->p_sigstk.ss_size = 0;
p->p_sigstk.ss_sp = 0;
p->p_flag &= ~P_ALTSTACK;
/*
* Reset no zombies if child dies flag as Solaris does.
*/
p->p_procsig->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN);
if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN)
ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL;
1994-05-24 10:09:53 +00:00
}
/*
* do_sigprocmask()
*
* Manipulate signal mask.
1994-05-24 10:09:53 +00:00
*/
static int
do_sigprocmask(p, how, set, oset, old)
struct proc *p;
int how;
sigset_t *set, *oset;
int old;
{
int error;
PROC_LOCK(p);
if (oset != NULL)
*oset = p->p_sigmask;
error = 0;
if (set != NULL) {
switch (how) {
case SIG_BLOCK:
SIG_CANTMASK(*set);
SIGSETOR(p->p_sigmask, *set);
break;
case SIG_UNBLOCK:
SIGSETNAND(p->p_sigmask, *set);
signotify(p);
break;
case SIG_SETMASK:
SIG_CANTMASK(*set);
if (old)
SIGSETLO(p->p_sigmask, *set);
else
p->p_sigmask = *set;
signotify(p);
break;
default:
error = EINVAL;
break;
}
}
PROC_UNLOCK(p);
return (error);
}
/*
* sigprocmask() - MP SAFE (XXXKSE not under KSE it isn't)
*/
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
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;
{
struct proc *p = td->td_proc;
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 = do_sigprocmask(p, 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;
{
struct proc *p = td->td_proc;
sigset_t set, oset;
int error;
1995-05-30 08:16:23 +00:00
OSIG2SIG(uap->mask, set);
error = do_sigprocmask(p, 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;
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};
#endif
/*
* MPSAFE
*/
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
sigpending(td, uap)
struct thread *td;
1994-05-24 10:09:53 +00:00
struct sigpending_args *uap;
{
struct proc *p = td->td_proc;
sigset_t siglist;
int error;
1994-05-24 10:09:53 +00:00
mtx_lock(&Giant);
PROC_LOCK(p);
siglist = p->p_siglist;
PROC_UNLOCK(p);
mtx_unlock(&Giant);
error = copyout(&siglist, uap->set, sizeof(sigset_t));
return(error);
}
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
#ifndef _SYS_SYSPROTO_H_
struct osigpending_args {
int dummy;
};
#endif
/*
* MPSAFE
*/
/* ARGSUSED */
int
osigpending(td, uap)
struct thread *td;
struct osigpending_args *uap;
{
struct proc *p = td->td_proc;
mtx_lock(&Giant);
PROC_LOCK(p);
SIG2OSIG(p->p_siglist, td->td_retval[0]);
PROC_UNLOCK(p);
mtx_unlock(&Giant);
1994-05-24 10:09:53 +00:00
return (0);
}
#endif /* COMPAT_43 */
1994-05-24 10:09:53 +00:00
#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;
1994-05-24 10:09:53 +00:00
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
1994-05-24 10:09:53 +00:00
}
mtx_lock(&Giant);
error = kern_sigaction(td, uap->signum, nsap, osap, 1);
mtx_unlock(&Giant);
if (osap && !error) {
vec.sv_handler = osap->sa_handler;
SIG2OSIG(osap->sa_mask, vec.sv_mask);
vec.sv_flags = osap->sa_flags;
vec.sv_flags &= ~SA_NOCLDWAIT;
vec.sv_flags ^= SA_RESTART;
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;
1994-05-24 10:09:53 +00:00
OSIG2SIG(uap->mask, set);
SIG_CANTMASK(set);
mtx_lock(&Giant);
PROC_LOCK(p);
SIG2OSIG(p->p_sigmask, td->td_retval[0]);
SIGSETOR(p->p_sigmask, set);
PROC_UNLOCK(p);
mtx_unlock(&Giant);
1994-05-24 10:09:53 +00:00
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);
mtx_lock(&Giant);
PROC_LOCK(p);
SIG2OSIG(p->p_sigmask, td->td_retval[0]);
SIGSETLO(p->p_sigmask, set);
signotify(p);
PROC_UNLOCK(p);
mtx_unlock(&Giant);
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. Note nonstandard calling convention:
* libc stub passes mask, not pointer, to save a copyin.
***** XXXKSE this doesn't make sense under KSE.
***** Do we suspend the thread or all threads in the process?
***** How do we suspend threads running NOW on another processor?
1994-05-24 10:09:53 +00:00
*/
#ifndef _SYS_SYSPROTO_H_
1994-05-24 10:09:53 +00:00
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;
register struct sigacts *ps;
1994-05-24 10:09:53 +00:00
/*
* 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.
*/
mtx_lock(&Giant);
PROC_LOCK(p);
ps = p->p_sigacts;
p->p_oldsigmask = p->p_sigmask;
p->p_flag |= P_OLDMASK;
SIG_CANTMASK(mask);
p->p_sigmask = mask;
signotify(p);
2002-06-29 02:00:02 +00:00
while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0)
/* void */;
PROC_UNLOCK(p);
mtx_unlock(&Giant);
/* always return EINTR rather than ERESTART... */
return (EINTR);
}
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
#ifndef _SYS_SYSPROTO_H_
struct osigsuspend_args {
osigset_t mask;
};
#endif
/*
* MPSAFE
*/
/* ARGSUSED */
int
osigsuspend(td, uap)
struct thread *td;
struct osigsuspend_args *uap;
{
struct proc *p = td->td_proc;
sigset_t mask;
register struct sigacts *ps;
mtx_lock(&Giant);
PROC_LOCK(p);
ps = p->p_sigacts;
p->p_oldsigmask = p->p_sigmask;
p->p_flag |= P_OLDMASK;
OSIG2SIG(uap->mask, mask);
SIG_CANTMASK(mask);
SIGSETLO(p->p_sigmask, mask);
signotify(p);
2002-06-29 02:00:02 +00:00
while (msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0)
1994-05-24 10:09:53 +00:00
/* void */;
PROC_UNLOCK(p);
mtx_unlock(&Giant);
1994-05-24 10:09:53 +00:00
/* 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;
1994-05-24 10:09:53 +00:00
register struct osigstack_args *uap;
{
struct proc *p = td->td_proc;
1994-05-24 10:09:53 +00:00
struct sigstack ss;
int error = 0;
mtx_lock(&Giant);
1994-05-24 10:09:53 +00:00
if (uap->oss != NULL) {
PROC_LOCK(p);
ss.ss_sp = p->p_sigstk.ss_sp;
ss.ss_onstack = sigonstack(cpu_getstack(td));
PROC_UNLOCK(p);
error = copyout(&ss, uap->oss, sizeof(struct sigstack));
if (error)
goto done2;
}
if (uap->nss != NULL) {
if ((error = copyin(uap->nss, &ss, sizeof(ss))) != 0)
goto done2;
PROC_LOCK(p);
p->p_sigstk.ss_sp = ss.ss_sp;
p->p_sigstk.ss_size = 0;
p->p_sigstk.ss_flags |= ss.ss_onstack & SS_ONSTACK;
p->p_flag |= P_ALTSTACK;
PROC_UNLOCK(p);
1994-05-24 10:09:53 +00:00
}
done2:
mtx_unlock(&Giant);
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;
int error = 0;
mtx_lock(&Giant);
1994-05-24 10:09:53 +00:00
oonstack = sigonstack(cpu_getstack(td));
if (oss != NULL) {
PROC_LOCK(p);
*oss = p->p_sigstk;
oss->ss_flags = (p->p_flag & P_ALTSTACK)
? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
PROC_UNLOCK(p);
}
if (ss != NULL) {
if (oonstack) {
error = EPERM;
goto done2;
}
if ((ss->ss_flags & ~SS_DISABLE) != 0) {
error = EINVAL;
goto done2;
}
if (!(ss->ss_flags & SS_DISABLE)) {
if (ss->ss_size < p->p_sysent->sv_minsigstksz) {
error = ENOMEM;
goto done2;
}
PROC_LOCK(p);
p->p_sigstk = *ss;
p->p_flag |= P_ALTSTACK;
PROC_UNLOCK(p);
} else {
PROC_LOCK(p);
p->p_flag &= ~P_ALTSTACK;
PROC_UNLOCK(p);
}
1994-05-24 10:09:53 +00:00
}
done2:
mtx_unlock(&Giant);
return (error);
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 = 0;
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);
mtx_lock(&Giant);
1994-05-24 10:09:53 +00:00
if (uap->pid > 0) {
/* kill single process */
if ((p = pfind(uap->pid)) == NULL) {
error = ESRCH;
} else if ((error = p_cansignal(td, p, uap->signum)) != 0) {
PROC_UNLOCK(p);
} else {
if (uap->signum)
psignal(p, uap->signum);
PROC_UNLOCK(p);
error = 0;
}
} else {
switch (uap->pid) {
case -1: /* broadcast signal */
error = killpg1(td, uap->signum, 0, 1);
break;
case 0: /* signal own process group */
error = killpg1(td, uap->signum, 0, 0);
break;
default: /* negative explicit process group */
error = killpg1(td, uap->signum, -uap->pid, 0);
break;
}
1994-05-24 10:09:53 +00:00
}
mtx_unlock(&Giant);
return(error);
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;
{
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);
mtx_lock(&Giant);
error = killpg1(td, uap->signum, uap->pgid, 0);
mtx_unlock(&Giant);
return (error);
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 process.
* 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(p, sig, code)
1994-05-24 10:09:53 +00:00
struct proc *p;
register int sig;
u_long code;
1994-05-24 10:09:53 +00:00
{
register struct sigacts *ps = p->p_sigacts;
PROC_LOCK(p);
if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(p->p_sigcatch, sig) &&
!SIGISMEMBER(p->p_sigmask, sig)) {
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)],
&p->p_sigmask, code);
1994-05-24 10:09:53 +00:00
#endif
(*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], sig,
&p->p_sigmask, code);
SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
if (!SIGISMEMBER(ps->ps_signodefer, sig))
SIGADDSET(p->p_sigmask, sig);
if (SIGISMEMBER(ps->ps_sigreset, sig)) {
/*
* See kern_sigaction() for origin of this code.
*/
SIGDELSET(p->p_sigcatch, sig);
if (sig != SIGCONT &&
sigprop(sig) & SA_IGNORE)
SIGADDSET(p->p_sigignore, sig);
ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
}
} else {
p->p_code = code; /* XXX for core dump/debugger */
p->p_sig = sig; /* XXX to verify code */
psignal(p, sig);
1994-05-24 10:09:53 +00:00
}
PROC_UNLOCK(p);
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.
*/
void
psignal(p, sig)
1994-05-24 10:09:53 +00:00
register struct proc *p;
register int sig;
1994-05-24 10:09:53 +00:00
{
register sig_t action;
struct thread *td;
register int prop;
1994-05-24 10:09:53 +00:00
KASSERT(_SIG_VALID(sig),
("psignal(): invalid signal %d\n", sig));
PROC_LOCK_ASSERT(p, MA_OWNED);
KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
prop = sigprop(sig);
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 p_sigignore,
* and if it is set to SIG_IGN,
* action will be SIG_DFL here.)
*/
if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
1994-05-24 10:09:53 +00:00
return;
if (SIGISMEMBER(p->p_sigmask, sig))
1994-05-24 10:09:53 +00:00
action = SIG_HOLD;
else if (SIGISMEMBER(p->p_sigcatch, sig))
1994-05-24 10:09:53 +00:00
action = SIG_CATCH;
else
action = SIG_DFL;
}
if (prop & SA_CONT)
SIG_STOPSIGMASK(p->p_siglist);
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);
p->p_flag &= ~P_CONTINUED;
1994-05-24 10:09:53 +00:00
}
SIGADDSET(p->p_siglist, sig);
signotify(p); /* uses schedlock */
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 p_siglist as
* it has no further action. If SIGCONT is held, we
* continue the process and leave the signal in
* p_siglist. If the process catches SIGCONT, let it
* handle the signal itself. If it isn't waiting on
* an event, 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(p->p_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(p->p_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);
FOREACH_THREAD_IN_PROC(p, td) {
if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) {
if (td->td_flags & TDF_CVWAITQ)
cv_abort(td);
else
abortsleep(td);
}
}
mtx_unlock_spin(&sched_lock);
goto out;
1994-05-24 10:09:53 +00:00
/*
* XXXKSE What about threads that are waiting on mutexes?
* Shouldn't they abort too?
* No, hopefully mutexes are short lived.. They'll
* eventually hit thread_suspend_check().
1994-05-24 10:09:53 +00:00
*/
} else if (p->p_state == PRS_NORMAL) {
if (prop & SA_CONT) {
/*
* Already active, don't need to start again.
*/
SIGDELSET(p->p_siglist, sig);
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 ((p->p_flag & P_TRACED) || (action != SIG_DFL) ||
!(prop & SA_STOP)) {
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td)
tdsignal(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;
mtx_lock_spin(&sched_lock);
FOREACH_THREAD_IN_PROC(p, td) {
if (TD_IS_SLEEPING(td) &&
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
(td->td_flags & TDF_SINTR))
thread_suspend_one(td);
}
if (p->p_suspcount == p->p_numthreads) {
mtx_unlock_spin(&sched_lock);
stop(p);
p->p_xstat = sig;
SIGDELSET(p->p_siglist, 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
PROC_LOCK(p->p_pptr);
if ((p->p_pptr->p_procsig->ps_flag &
PS_NOCLDSTOP) == 0) {
psignal(p->p_pptr, SIGCHLD);
}
PROC_UNLOCK(p->p_pptr);
} else {
mtx_unlock_spin(&sched_lock);
}
goto out;
}
else
1994-05-24 10:09:53 +00:00
goto runfast;
/* NOTREACHED */
} else {
/* Not in "NORMAL" state. discard the signal. */
SIGDELSET(p->p_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);
FOREACH_THREAD_IN_PROC(p, td)
tdsignal(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
tdsignal(struct thread *td, int sig, sig_t action)
{
struct proc *p = td->td_proc;
register int prop;
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
}
}
1994-05-24 10:09:53 +00:00
/*
* Defer further processing for signals which are held,
* except that stopped processes must be continued by SIGCONT.
*/
if (action == SIG_HOLD) {
return;
}
if (TD_IS_SLEEPING(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().
*/
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);
return;
}
/*
* Raise priority to at least PUSER.
*/
if (td->td_priority > PUSER) {
td->td_priority = PUSER;
}
}
if (td->td_flags & TDF_CVWAITQ)
cv_abort(td);
else
abortsleep(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.
*/
if (TD_IS_RUNNING(td) && td != curthread) {
forward_signal(td);
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
}
}
#endif
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
*/
int
issignal(td)
struct thread *td;
1994-05-24 10:09:53 +00:00
{
struct proc *p;
sigset_t mask;
register int sig, prop;
1994-05-24 10:09:53 +00:00
p = td->td_proc;
PROC_LOCK_ASSERT(p, MA_OWNED);
2002-08-26 05:02:56 +00:00
WITNESS_SLEEP(1, &p->p_mtx.mtx_object);
1994-05-24 10:09:53 +00:00
for (;;) {
int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
mask = p->p_siglist;
SIGSETNAND(mask, p->p_sigmask);
1994-05-24 10:09:53 +00:00
if (p->p_flag & P_PPWAIT)
SIG_STOPSIGMASK(mask);
if (SIGISEMPTY(mask)) /* no signal to send */
1994-05-24 10:09:53 +00:00
return (0);
sig = sig_ffs(&mask);
prop = sigprop(sig);
_STOPEVENT(p, S_SIG, sig);
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(p->p_sigignore, sig) && (traced == 0)) {
SIGDELSET(p->p_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
*/
p->p_xstat = sig;
PROC_LOCK(p->p_pptr);
1994-05-24 10:09:53 +00:00
psignal(p->p_pptr, SIGCHLD);
PROC_UNLOCK(p->p_pptr);
mtx_lock_spin(&sched_lock);
stop(p); /* uses schedlock too eventually */
thread_suspend_one(td);
PROC_UNLOCK(p);
DROP_GIANT();
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
mtx_unlock_spin(&sched_lock);
PICKUP_GIANT();
PROC_LOCK(p);
1994-05-24 10:09:53 +00:00
/*
* If the traced bit got turned off, go back up
* to the top to rescan signals. This ensures
* that p_sig* and ps_sigact are consistent.
*/
if ((p->p_flag & P_TRACED) == 0)
continue;
/*
* If parent wants us to take the signal,
* then it will leave it in p->p_xstat;
* otherwise we just look for signals again.
*/
SIGDELSET(p->p_siglist, sig); /* clear old signal */
sig = p->p_xstat;
if (sig == 0)
1994-05-24 10:09:53 +00:00
continue;
/*
* Put the new signal into p_siglist. If the
* signal is being masked, look for other signals.
1994-05-24 10:09:53 +00:00
*/
SIGADDSET(p->p_siglist, sig);
if (SIGISMEMBER(p->p_sigmask, sig))
1994-05-24 10:09:53 +00:00
continue;
signotify(p);
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 */
p->p_xstat = sig;
mtx_lock_spin(&sched_lock);
if (p->p_suspcount+1 == p->p_numthreads) {
mtx_unlock_spin(&sched_lock);
PROC_LOCK(p->p_pptr);
if ((p->p_pptr->p_procsig->ps_flag &
PS_NOCLDSTOP) == 0) {
psignal(p->p_pptr, SIGCHLD);
}
PROC_UNLOCK(p->p_pptr);
mtx_lock_spin(&sched_lock);
}
stop(p);
thread_suspend_one(td);
PROC_UNLOCK(p);
DROP_GIANT();
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
mtx_unlock_spin(&sched_lock);
PICKUP_GIANT();
PROC_LOCK(p);
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(p->p_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 and the scheduler
* lock held.
1994-05-24 10:09:53 +00:00
*/
static void
1994-05-24 10:09:53 +00:00
stop(p)
register struct proc *p;
{
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
}
/*
* 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;
SIGDELSET(p->p_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, p->p_flag & P_OLDMASK ?
&p->p_oldsigmask : &p->p_sigmask, 0);
1994-05-24 10:09:53 +00:00
#endif
_STOPEVENT(p, S_SIG, sig);
1994-05-24 10:09:53 +00:00
if (action == SIG_DFL) {
/*
* Default action, where the default is to kill
* the process. (Other cases were ignored above.)
*/
sigexit(td, sig);
1994-05-24 10:09:53 +00:00
/* NOTREACHED */
} else {
/*
* If we get here, the signal must be caught.
*/
KASSERT(action != SIG_IGN && !SIGISMEMBER(p->p_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 (p->p_flag & P_OLDMASK) {
returnmask = p->p_oldsigmask;
p->p_flag &= ~P_OLDMASK;
1994-05-24 10:09:53 +00:00
} else
returnmask = p->p_sigmask;
SIGSETOR(p->p_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]);
if (!SIGISMEMBER(ps->ps_signodefer, sig))
SIGADDSET(p->p_sigmask, sig);
if (SIGISMEMBER(ps->ps_sigreset, sig)) {
/*
* See kern_sigaction() for origin of this code.
*/
SIGDELSET(p->p_sigcatch, sig);
if (sig != SIGCONT &&
sigprop(sig) & SA_IGNORE)
SIGADDSET(p->p_sigignore, sig);
ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
}
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 (p->p_flag & P_KSES)
if (signal_upcall(p, sig))
return;
(*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.
*/
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
*/
PROC_UNLOCK(p);
if (!mtx_owned(&Giant))
mtx_lock(&Giant);
if (coredump(td) == 0)
sig |= WCOREFLAG;
if (kern_logsigexit)
log(LOG_INFO,
"pid %d (%s), uid %d: exited on signal %d%s\n",
p->p_pid, p->p_comm,
td->td_ucred ? td->td_ucred->cr_uid : -1,
sig &~ WCOREFLAG,
sig & WCOREFLAG ? " (core dumped)" : "");
} else {
PROC_UNLOCK(p);
if (!mtx_owned(&Giant))
mtx_lock(&Giant);
}
exit1(td, W_EXITCODE(0, sig));
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;
struct mount *mp;
char *name; /* name of corefile */
off_t limit;
PROC_LOCK(p);
_STOPEVENT(p, S_CORE, 0);
if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) {
PROC_UNLOCK(p);
return (EFAULT);
}
/*
* Note that the bulk of limit checking is done after
* the corefile is created. The exception is if the limit
* for corefiles is 0, in which case we don't bother
* creating the corefile at all. This layout means that
* a corefile is truncated instead of not being created,
* if it is larger than the limit.
*/
limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
if (limit == 0) {
PROC_UNLOCK(p);
return 0;
}
PROC_UNLOCK(p);
restart:
name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid);
if (name == NULL)
return (EINVAL);
NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */
flags = O_CREAT | FWRITE | O_NOFOLLOW;
error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR);
free(name, M_TEMP);
if (error)
return (error);
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
/* 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 out2;
}
VOP_UNLOCK(vp, 0, td);
lf.l_whence = SEEK_SET;
lf.l_start = 0;
lf.l_len = 0;
lf.l_type = F_WRLCK;
error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK);
if (error)
goto out2;
if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
lf.l_type = F_UNLCK;
VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
if ((error = vn_close(vp, FWRITE, cred, td)) != 0)
return (error);
if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
return (error);
goto restart;
}
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;
lf.l_type = F_UNLCK;
VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK);
vn_finished_write(mp);
out2:
error1 = vn_close(vp, FWRITE, cred, td);
if (error == 0)
error = error1;
return (error);
}
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;
mtx_lock(&Giant);
PROC_LOCK(p);
1994-05-24 10:09:53 +00:00
psignal(p, SIGSYS);
PROC_UNLOCK(p);
mtx_unlock(&Giant);
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);
}