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freebsd/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/resourcevar.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/wait.h>
#include <sys/ktr.h>
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#include <sys/ktrace.h>
#include <sys/syslog.h>
#include <sys/stat.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>
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Commit major SMP cleanups and move the BGL (big giant lock) in the syscall path inward. A system call may select whether it needs the MP lock or not (the default being that it does need it). A great deal of conditional SMP code for various deadended experiments has been removed. 'cil' and 'cml' have been removed entirely, and the locking around the cpl has been removed. The conditional separately-locked fast-interrupt code has been removed, meaning that interrupts must hold the CPL now (but they pretty much had to anyway). Another reason for doing this is that the original separate-lock for interrupts just doesn't apply to the interrupt thread mechanism being contemplated. Modifications to the cpl may now ONLY occur while holding the MP lock. For example, if an otherwise MP safe syscall needs to mess with the cpl, it must hold the MP lock for the duration and must (as usual) save/restore the cpl in a nested fashion. This is precursor work for the real meat coming later: avoiding having to hold the MP lock for common syscalls and I/O's and interrupt threads. It is expected that the spl mechanisms and new interrupt threading mechanisms will be able to run in tandem, allowing a slow piecemeal transition to occur. This patch should result in a moderate performance improvement due to the considerable amount of code that has been removed from the critical path, especially the simplification of the spl*() calls. The real performance gains will come later. Approved by: jkh Reviewed by: current, bde (exception.s) Some work taken from: luoqi's patch
2000-03-28 07:16:37 +00:00
#include <machine/ipl.h>
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#include <machine/cpu.h>
#include <machine/mutex.h>
#include <machine/smp.h>
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#define ONSIG 32 /* NSIG for osig* syscalls. XXX. */
static int coredump __P((struct proc *));
static int do_sigaction __P((struct proc *p, int sig, struct sigaction *act,
struct sigaction *oact, int old));
static int do_sigprocmask __P((struct proc *p, int how, sigset_t *set,
sigset_t *oset, int old));
static char *expand_name __P((const char *, uid_t, pid_t));
static int killpg1 __P((struct proc *cp, int sig, int pgid, int all));
static int sig_ffs __P((sigset_t *set));
static int sigprop __P((int sig));
static void stop __P((struct proc *));
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)");
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/*
* Can process p, with pcred pc, send the signal sig to process q?
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*/
#define CANSIGNAL(p, q, sig) \
o Centralize inter-process access control, introducing: int p_can(p1, p2, operation, privused) which allows specification of subject process, object process, inter-process operation, and an optional call-by-reference privused flag, allowing the caller to determine if privilege was required for the call to succeed. This allows jail, kern.ps_showallprocs and regular credential-based interaction checks to occur in one block of code. Possible operations are P_CAN_SEE, P_CAN_SCHED, P_CAN_KILL, and P_CAN_DEBUG. p_can currently breaks out as a wrapper to a series of static function checks in kern_prot, which should not be invoked directly. o Commented out capabilities entries are included for some checks. o Update most inter-process authorization to make use of p_can() instead of manual checks, PRISON_CHECK(), P_TRESPASS(), and kern.ps_showallprocs. o Modify suser{,_xxx} to use const arguments, as it no longer modifies process flags due to the disabling of ASU. o Modify some checks/errors in procfs so that ENOENT is returned instead of ESRCH, further improving concealment of processes that should not be visible to other processes. Also introduce new access checks to improve hiding of processes for procfs_lookup(), procfs_getattr(), procfs_readdir(). Correct a bug reported by bp concerning not handling the CREATE case in procfs_lookup(). Remove volatile flag in procfs that caused apparently spurious qualifier warnigns (approved by bde). o Add comment noting that ktrace() has not been updated, as its access control checks are different from ptrace(), whereas they should probably be the same. Further discussion should happen on this topic. Reviewed by: bde, green, phk, freebsd-security, others Approved by: bde Obtained from: TrustedBSD Project
2000-08-30 04:49:09 +00:00
(!p_can(p, q, P_CAN_KILL, NULL) || \
((sig) == SIGCONT && (q)->p_session == (p)->p_session))
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/*
* Policy -- Can real uid ruid with ucred uc send a signal to process q?
*/
#define CANSIGIO(ruid, uc, q) \
((uc)->cr_uid == 0 || \
(ruid) == (q)->p_cred->p_ruid || \
(uc)->cr_uid == (q)->p_cred->p_ruid || \
(ruid) == (q)->p_ucred->cr_uid || \
(uc)->cr_uid == (q)->p_ucred->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().
*
* MP SAFE
*/
int
CURSIG(struct proc *p)
{
sigset_t tmpset;
int r;
tmpset = p->p_siglist;
SIGSETNAND(tmpset, p->p_sigmask);
if (SIGISEMPTY(p->p_siglist) ||
(!(p->p_flag & P_TRACED) && SIGISEMPTY(tmpset))) {
return(0);
}
mtx_enter(&Giant, MTX_DEF);
r = issignal(p);
mtx_exit(&Giant, MTX_DEF);
return(r);
}
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);
}
/*
* do_sigaction
* sigaction
* osigaction
*/
static int
do_sigaction(p, sig, act, oact, old)
struct proc *p;
register int sig;
struct sigaction *act, *oact;
int old;
{
register struct sigacts *ps = p->p_sigacts;
if (sig <= 0 || sig > _SIG_MAXSIG)
return (EINVAL);
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)
return (EINVAL);
/*
* Change setting atomically.
*/
(void) splhigh();
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)] = act->sa_handler;
SIGADDSET(ps->ps_siginfo, sig);
} else {
ps->ps_sigact[_SIG_IDX(sig)] =
(__sighandler_t *)act->sa_sigaction;
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, seg);
#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;
}
/*
* 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);
}
if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old)
SIGDELSET(ps->ps_osigset, sig);
else
SIGADDSET(ps->ps_osigset, sig);
(void) spl0();
}
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
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/* ARGSUSED */
int
sigaction(p, uap)
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struct proc *p;
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)
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return (error);
}
error = do_sigaction(p, uap->sig, actp, oactp, 0);
if (oactp && !error) {
error = copyout(oactp, uap->oact, sizeof(oact));
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}
return (error);
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}
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
#ifndef _SYS_SYSPROTO_H_
struct osigaction_args {
int signum;
struct osigaction *nsa;
struct osigaction *osa;
};
#endif
/* ARGSUSED */
int
osigaction(p, uap)
struct proc *p;
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 = do_sigaction(p, uap->signum, nsap, osap, 1);
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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}
#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;
for (i = 1; i <= NSIG; i++)
if (sigprop(i) & SA_IGNORE && i != SIGCONT)
SIGADDSET(p->p_sigignore, i);
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}
/*
* Reset signals for an exec of the specified process.
*/
void
execsigs(p)
register struct proc *p;
{
register struct sigacts *ps = p->p_sigacts;
register int 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).
*/
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);
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}
ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL;
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}
/*
* 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;
/*
* Reset no zombies if child dies flag as Solaris does.
*/
p->p_procsig->ps_flag &= ~PS_NOCLDWAIT;
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}
/*
* do_sigprocmask() - MP SAFE ONLY IF p == curproc
*
* Manipulate signal mask. This routine is MP SAFE *ONLY* if
* p == curproc. Also remember that in order to remain MP SAFE
* no spl*() calls may be made.
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*/
static int
do_sigprocmask(p, how, set, oset, old)
struct proc *p;
int how;
sigset_t *set, *oset;
int old;
{
int error;
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);
break;
case SIG_SETMASK:
SIG_CANTMASK(*set);
if (old)
SIGSETLO(p->p_sigmask, *set);
else
p->p_sigmask = *set;
break;
default:
error = EINVAL;
break;
}
}
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;
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};
#endif
int
sigprocmask(p, uap)
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register struct proc *p;
struct sigprocmask_args *uap;
{
sigset_t set, oset;
sigset_t *setp, *osetp;
int error;
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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);
}
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#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
/*
* osigprocmask() - MP SAFE
*/
#ifndef _SYS_SYSPROTO_H_
struct osigprocmask_args {
int how;
osigset_t mask;
};
#endif
int
osigprocmask(p, uap)
register struct proc *p;
struct osigprocmask_args *uap;
{
sigset_t set, oset;
int error;
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OSIG2SIG(uap->mask, set);
error = do_sigprocmask(p, uap->how, &set, &oset, 1);
SIG2OSIG(oset, p->p_retval[0]);
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return (error);
}
#endif /* COMPAT_43 */
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#ifndef _SYS_SYSPROTO_H_
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struct sigpending_args {
sigset_t *set;
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};
#endif
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/* ARGSUSED */
int
sigpending(p, uap)
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struct proc *p;
struct sigpending_args *uap;
{
return (copyout(&p->p_siglist, uap->set, sizeof(sigset_t)));
}
#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */
#ifndef _SYS_SYSPROTO_H_
struct osigpending_args {
int dummy;
};
#endif
/* ARGSUSED */
int
osigpending(p, uap)
struct proc *p;
struct osigpending_args *uap;
{
SIG2OSIG(p->p_siglist, p->p_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
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/* ARGSUSED */
int
osigvec(p, uap)
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struct proc *p;
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)
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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 = do_sigaction(p, uap->signum, nsap, osap, 1);
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;
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#ifdef COMPAT_SUNOS
vec.sv_flags &= ~SA_NOCLDSTOP;
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#endif
error = copyout(&vec, uap->osv, sizeof(vec));
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}
return (error);
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}
#ifndef _SYS_SYSPROTO_H_
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struct osigblock_args {
int mask;
};
#endif
int
osigblock(p, uap)
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register struct proc *p;
struct osigblock_args *uap;
{
sigset_t set;
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OSIG2SIG(uap->mask, set);
SIG_CANTMASK(set);
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(void) splhigh();
SIG2OSIG(p->p_sigmask, p->p_retval[0]);
SIGSETOR(p->p_sigmask, set);
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(void) spl0();
return (0);
}
#ifndef _SYS_SYSPROTO_H_
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struct osigsetmask_args {
int mask;
};
#endif
int
osigsetmask(p, uap)
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struct proc *p;
struct osigsetmask_args *uap;
{
sigset_t set;
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OSIG2SIG(uap->mask, set);
SIG_CANTMASK(set);
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(void) splhigh();
SIG2OSIG(p->p_sigmask, p->p_retval[0]);
SIGSETLO(p->p_sigmask, set);
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(void) spl0();
return (0);
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
/*
* Suspend process until signal, providing mask to be set
* in the meantime. Note nonstandard calling convention:
* libc stub passes mask, not pointer, to save a copyin.
*/
#ifndef _SYS_SYSPROTO_H_
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struct sigsuspend_args {
const sigset_t *sigmask;
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};
#endif
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/* ARGSUSED */
int
sigsuspend(p, uap)
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register struct proc *p;
struct sigsuspend_args *uap;
{
sigset_t mask;
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register struct sigacts *ps = p->p_sigacts;
int error;
error = copyin(uap->sigmask, &mask, sizeof(mask));
if (error)
return (error);
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/*
* When returning from sigsuspend, we want
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* 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.
*/
p->p_oldsigmask = p->p_sigmask;
p->p_flag |= P_OLDMASK;
SIG_CANTMASK(mask);
p->p_sigmask = mask;
while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0)
/* void */;
/* 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
/* ARGSUSED */
int
osigsuspend(p, uap)
register struct proc *p;
struct osigsuspend_args *uap;
{
sigset_t mask;
register struct sigacts *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);
while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "opause", 0) == 0)
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/* void */;
/* always return EINTR rather than ERESTART... */
return (EINTR);
}
#endif /* COMPAT_43 */
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#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#ifndef _SYS_SYSPROTO_H_
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struct osigstack_args {
struct sigstack *nss;
struct sigstack *oss;
};
#endif
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/* ARGSUSED */
int
osigstack(p, uap)
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struct proc *p;
register struct osigstack_args *uap;
{
struct sigstack ss;
int error = 0;
ss.ss_sp = p->p_sigstk.ss_sp;
ss.ss_onstack = p->p_sigstk.ss_flags & SS_ONSTACK;
if (uap->oss && (error = copyout(&ss, uap->oss,
sizeof(struct sigstack))))
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return (error);
if (uap->nss && (error = copyin(uap->nss, &ss, sizeof(ss))) == 0) {
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;
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}
return (error);
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
#ifndef _SYS_SYSPROTO_H_
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struct sigaltstack_args {
stack_t *ss;
stack_t *oss;
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};
#endif
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/* ARGSUSED */
int
sigaltstack(p, uap)
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struct proc *p;
register struct sigaltstack_args *uap;
{
stack_t ss;
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int error;
if ((p->p_flag & P_ALTSTACK) == 0)
p->p_sigstk.ss_flags |= SS_DISABLE;
if (uap->oss && (error = copyout(&p->p_sigstk, uap->oss,
sizeof(stack_t))))
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return (error);
if (uap->ss == 0)
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return (0);
if ((error = copyin(uap->ss, &ss, sizeof(ss))))
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return (error);
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
if (ss.ss_flags & SS_DISABLE) {
if (p->p_sigstk.ss_flags & SS_ONSTACK)
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return (EINVAL);
p->p_flag &= ~P_ALTSTACK;
p->p_sigstk.ss_flags = ss.ss_flags;
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return (0);
}
if (ss.ss_size < MINSIGSTKSZ)
return (ENOMEM);
p->p_flag |= P_ALTSTACK;
p->p_sigstk = ss;
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return (0);
}
/*
* Common code for kill process group/broadcast kill.
* cp is calling process.
*/
int
killpg1(cp, sig, pgid, all)
register struct proc *cp;
int sig, pgid, all;
{
register struct proc *p;
struct pgrp *pgrp;
int nfound = 0;
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if (all)
/*
* broadcast
*/
LIST_FOREACH(p, &allproc, p_list) {
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if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
p == cp || !CANSIGNAL(cp, p, sig))
continue;
nfound++;
if (sig)
psignal(p, sig);
}
else {
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if (pgid == 0)
/*
* zero pgid means send to my process group.
*/
pgrp = cp->p_pgrp;
else {
pgrp = pgfind(pgid);
if (pgrp == NULL)
return (ESRCH);
}
LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
p->p_stat == SZOMB ||
!CANSIGNAL(cp, p, sig))
continue;
nfound++;
if (sig)
psignal(p, sig);
}
}
return (nfound ? 0 : ESRCH);
}
#ifndef _SYS_SYSPROTO_H_
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struct kill_args {
int pid;
int signum;
};
#endif
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/* ARGSUSED */
int
kill(cp, uap)
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register struct proc *cp;
register struct kill_args *uap;
{
register struct proc *p;
if ((u_int)uap->signum > _SIG_MAXSIG)
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return (EINVAL);
if (uap->pid > 0) {
/* kill single process */
if ((p = pfind(uap->pid)) == NULL)
return (ESRCH);
if (!CANSIGNAL(cp, p, uap->signum))
1994-05-24 10:09:53 +00:00
return (EPERM);
if (uap->signum)
psignal(p, uap->signum);
return (0);
}
switch (uap->pid) {
case -1: /* broadcast signal */
return (killpg1(cp, uap->signum, 0, 1));
case 0: /* signal own process group */
return (killpg1(cp, uap->signum, 0, 0));
default: /* negative explicit process group */
return (killpg1(cp, uap->signum, -uap->pid, 0));
}
/* NOTREACHED */
}
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#ifndef _SYS_SYSPROTO_H_
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struct okillpg_args {
int pgid;
int signum;
};
#endif
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/* ARGSUSED */
int
okillpg(p, uap)
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struct proc *p;
register struct okillpg_args *uap;
{
if ((u_int)uap->signum > _SIG_MAXSIG)
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return (EINVAL);
return (killpg1(p, uap->signum, uap->pgid, 0));
}
#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 && (pgrp = pgfind(pgid)))
pgsignal(pgrp, sig, 0);
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}
/*
* Send a signal to a process group. If checktty is 1,
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* 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)
LIST_FOREACH(p, &pgrp->pg_members, p_pglist)
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if (checkctty == 0 || p->p_flag & P_CONTROLT)
psignal(p, sig);
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}
/*
* Send a signal caused by a trap to the current process.
* If it will be caught immediately, deliver it with correct code.
* Otherwise, post it normally.
*/
void
trapsignal(p, sig, code)
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struct proc *p;
register int sig;
u_long code;
1994-05-24 10:09:53 +00:00
{
register struct sigacts *ps = p->p_sigacts;
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(p, KTR_PSIG))
ktrpsig(p->p_tracep, sig, ps->ps_sigact[_SIG_IDX(sig)],
&p->p_sigmask, code);
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#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 do_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
}
}
/*
* 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)
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register struct proc *p;
register int sig;
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{
register int s, prop;
register sig_t action;
if (sig > _SIG_MAXSIG || sig <= 0) {
printf("psignal: signal %d\n", sig);
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panic("psignal signal number");
}
KNOTE(&p->p_klist, NOTE_SIGNAL | sig);
prop = sigprop(sig);
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/*
* 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))
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action = SIG_DFL;
else {
/*
* If the signal is being ignored,
* then we forget about it immediately.
* (Note: we don't set SIGCONT in p_sigignore,
* and if it is set to SIG_IGN,
* action will be SIG_DFL here.)
*/
if (SIGISMEMBER(p->p_sigignore, sig) || (p->p_flag & P_WEXIT))
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return;
if (SIGISMEMBER(p->p_sigmask, sig))
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action = SIG_HOLD;
else if (SIGISMEMBER(p->p_sigcatch, sig))
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action = SIG_CATCH;
else
action = SIG_DFL;
}
if (p->p_nice > NZERO && action == SIG_DFL && (prop & SA_KILL) &&
(p->p_flag & P_TRACED) == 0)
p->p_nice = NZERO;
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)
return;
SIG_CONTSIGMASK(p->p_siglist);
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}
SIGADDSET(p->p_siglist, sig);
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/*
* 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_stat != SSTOP))
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return;
s = splhigh();
switch (p->p_stat) {
case SSLEEP:
/*
* If process is sleeping uninterruptibly
* we can't interrupt the sleep... the signal will
* be noticed when the process returns through
* trap() or syscall().
*/
if ((p->p_flag & P_SINTR) == 0)
goto out;
/*
* Process is sleeping and traced... make it runnable
* so it can discover the signal in issignal() and stop
* for the parent.
*/
if (p->p_flag & P_TRACED)
goto run;
/*
* If SIGCONT is default (or ignored) and process is
* asleep, we are finished; the process should not
* be awakened.
*/
if ((prop & SA_CONT) && action == SIG_DFL) {
SIGDELSET(p->p_siglist, sig);
1994-05-24 10:09:53 +00:00
goto out;
}
/*
* When a sleeping process receives a stop
* signal, process immediately if possible.
* All other (caught or default) signals
* cause the process to run.
*/
if (prop & SA_STOP) {
if (action != SIG_DFL)
goto runfast;
/*
* If a child holding parent blocked,
* stopping could cause deadlock.
*/
if (p->p_flag & P_PPWAIT)
goto out;
SIGDELSET(p->p_siglist, sig);
p->p_xstat = sig;
if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
1994-05-24 10:09:53 +00:00
psignal(p->p_pptr, SIGCHLD);
stop(p);
goto out;
} else
goto runfast;
/*NOTREACHED*/
case SSTOP:
/*
* If traced process is already stopped,
* then no further action is necessary.
*/
if (p->p_flag & P_TRACED)
goto out;
/*
* Kill signal always sets processes running.
*/
if (sig == SIGKILL)
1994-05-24 10:09:53 +00:00
goto runfast;
if (prop & SA_CONT) {
/*
* If SIGCONT is default (or ignored), we continue the
* process but don't leave the signal in p_siglist, as
* it has no further action. If SIGCONT is held, we
* continue the process and leave the signal in
* p_siglist. If the process catches SIGCONT, let it
* handle the signal itself. If it isn't waiting on
* an event, then it goes back to run state.
* Otherwise, process goes back to sleep state.
*/
if (action == SIG_DFL)
SIGDELSET(p->p_siglist, sig);
1994-05-24 10:09:53 +00:00
if (action == SIG_CATCH)
goto runfast;
if (p->p_wchan == 0)
goto run;
p->p_stat = SSLEEP;
goto out;
}
if (prop & SA_STOP) {
/*
* Already stopped, don't need to stop again.
* (If we did the shell could get confused.)
*/
SIGDELSET(p->p_siglist, sig);
1994-05-24 10:09:53 +00:00
goto out;
}
/*
* If process is sleeping interruptibly, then simulate a
* wakeup so that when it is continued, it will be made
* runnable and can look at the signal. But don't make
* the process runnable, leave it stopped.
*/
if (p->p_wchan && p->p_flag & P_SINTR)
unsleep(p);
goto out;
default:
/*
* SRUN, SIDL, SZOMB do nothing with the signal,
* other than kicking ourselves if we are running.
* It will either never be noticed, or noticed very soon.
*/
if (p == curproc)
signotify(p);
#ifdef SMP
else if (p->p_stat == SRUN)
forward_signal(p);
#endif
1994-05-24 10:09:53 +00:00
goto out;
}
/*NOTREACHED*/
runfast:
/*
* Raise priority to at least PUSER.
*/
if (p->p_priority > PUSER)
p->p_priority = PUSER;
run:
setrunnable(p);
out:
splx(s);
}
/*
* If the current process has received a signal (should be caught or cause
* termination, should interrupt current syscall), return the signal number.
* Stop signals with default action are processed immediately, then cleared;
* they aren't returned. This is checked after each entry to the system for
* a syscall or trap (though this can usually be done without calling issignal
* by checking the pending signal masks in the CURSIG macro.) The normal call
* sequence is
*
* while (sig = CURSIG(curproc))
* postsig(sig);
1994-05-24 10:09:53 +00:00
*/
int
1994-05-24 10:09:53 +00:00
issignal(p)
register struct proc *p;
{
sigset_t mask;
register int sig, prop;
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 (!SIGNOTEMPTY(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, and stay
* stopped until released by the parent.
*/
p->p_xstat = sig;
1994-05-24 10:09:53 +00:00
psignal(p->p_pptr, SIGCHLD);
do {
stop(p);
mi_switch();
} while (!trace_req(p)
&& p->p_flag & P_TRACED);
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.
*/
SIGADDSET(p->p_siglist, sig);
if (SIGISMEMBER(p->p_sigmask, sig))
1994-05-24 10:09:53 +00:00
continue;
}
/*
* Decide whether the signal should be returned.
* Return the signal's number, or fall through
* to clear it from the pending mask.
*/
switch ((int)(intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) {
1994-05-24 10:09:53 +00:00
case (int)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))
break; /* == ignore */
p->p_xstat = sig;
1994-05-24 10:09:53 +00:00
stop(p);
if ((p->p_pptr->p_procsig->ps_flag & PS_NOCLDSTOP) == 0)
1994-05-24 10:09:53 +00:00
psignal(p->p_pptr, SIGCHLD);
mi_switch();
break;
} else if (prop & SA_IGNORE) {
/*
* Except for SIGCONT, shouldn't get here.
* Default action is to ignore; drop it.
*/
break; /* == ignore */
} else
return (sig);
1994-05-24 10:09:53 +00:00
/*NOTREACHED*/
case (int)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.
*/
void
1994-05-24 10:09:53 +00:00
stop(p)
register struct proc *p;
{
p->p_stat = SSTOP;
p->p_flag &= ~P_WAITED;
wakeup((caddr_t)p->p_pptr);
}
/*
* Take the action for the specified signal
* from the current set of pending signals.
*/
void
postsig(sig)
register int sig;
1994-05-24 10:09:53 +00:00
{
register struct proc *p = curproc;
struct sigacts *ps = p->p_sigacts;
sig_t action;
sigset_t returnmask;
int code;
1994-05-24 10:09:53 +00:00
KASSERT(sig != 0, ("postsig"));
SIGDELSET(p->p_siglist, sig);
action = ps->ps_sigact[_SIG_IDX(sig)];
1994-05-24 10:09:53 +00:00
#ifdef KTRACE
if (KTRPOINT(p, KTR_PSIG))
ktrpsig(p->p_tracep, 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(p, 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.
*/
(void) splhigh();
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 do_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
(void) spl0();
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
}
(*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;
{
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,
p->p_cred && 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(p, sig)
1994-05-24 10:09:53 +00:00
register struct proc *p;
int sig;
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
*/
if (coredump(p) == 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,
p->p_cred && p->p_ucred ? p->p_ucred->cr_uid : -1,
sig &~ WCOREFLAG,
sig & WCOREFLAG ? " (core dumped)" : "");
1994-05-24 10:09:53 +00:00
}
exit1(p, 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; {
char *temp;
char buf[11]; /* Buffer for pid/uid -- max 4B */
int i, n;
char *format = corefilename;
size_t namelen;
temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT);
if (temp == NULL)
return NULL;
namelen = strlen(name);
for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) {
int l;
switch (format[i]) {
case '%': /* Format character */
i++;
switch (format[i]) {
case '%':
temp[n++] = '%';
break;
case 'N': /* process name */
if ((n + namelen) > MAXPATHLEN) {
log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
pid, name, uid, temp, name);
free(temp, M_TEMP);
return NULL;
}
memcpy(temp+n, name, namelen);
n += namelen;
break;
case 'P': /* process id */
l = sprintf(buf, "%u", pid);
if ((n + l) > MAXPATHLEN) {
log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
pid, name, uid, temp, name);
free(temp, M_TEMP);
return NULL;
}
memcpy(temp+n, buf, l);
n += l;
break;
case 'U': /* user id */
l = sprintf(buf, "%u", uid);
if ((n + l) > MAXPATHLEN) {
log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n",
pid, name, uid, temp, name);
free(temp, M_TEMP);
return NULL;
}
memcpy(temp+n, buf, l);
n += l;
break;
default:
log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format);
}
break;
default:
temp[n++] = format[i];
}
}
temp[n] = '\0';
return temp;
}
/*
* 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(p)
register struct proc *p;
{
register struct vnode *vp;
1999-11-21 12:38:21 +00:00
register struct ucred *cred = p->p_ucred;
struct nameidata nd;
struct vattr vattr;
int error, error1, flags;
struct mount *mp;
char *name; /* name of corefile */
off_t limit;
STOPEVENT(p, S_CORE, 0);
if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0)
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)
return 0;
restart:
name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p);
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;
if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
VOP_UNLOCK(vp, 0, p);
if ((error = vn_close(vp, FWRITE, cred, p)) != 0)
return (error);
if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
return (error);
goto restart;
}
/* Don't dump to non-regular files or files with links. */
if (vp->v_type != VREG ||
VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) {
error = EFAULT;
goto out;
}
VATTR_NULL(&vattr);
vattr.va_size = 0;
VOP_LEASE(vp, p, cred, LEASE_WRITE);
VOP_SETATTR(vp, &vattr, cred, p);
p->p_acflag |= ACORE;
error = p->p_sysent->sv_coredump ?
p->p_sysent->sv_coredump(p, vp, limit) :
ENOSYS;
out:
VOP_UNLOCK(vp, 0, p);
vn_finished_write(mp);
error1 = vn_close(vp, FWRITE, cred, p);
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
1994-05-24 10:09:53 +00:00
/* ARGSUSED */
int
nosys(p, args)
1994-05-24 10:09:53 +00:00
struct proc *p;
struct nosys_args *args;
{
psignal(p, SIGSYS);
return (EINVAL);
}
/*
* Send a signal to a SIGIO or SIGURG to a process or process group using
* stored credentials rather than those of the current process.
*/
void
pgsigio(sigio, sig, checkctty)
struct sigio *sigio;
int sig, checkctty;
{
if (sigio == NULL)
return;
if (sigio->sio_pgid > 0) {
if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred,
sigio->sio_proc))
psignal(sigio->sio_proc, sig);
} else if (sigio->sio_pgid < 0) {
struct proc *p;
LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist)
if (CANSIGIO(sigio->sio_ruid, sigio->sio_ucred, p) &&
(checkctty == 0 || (p->p_flag & P_CONTROLT)))
psignal(p, sig);
}
}
static int
filt_sigattach(struct knote *kn)
{
struct proc *p = curproc;
kn->kn_ptr.p_proc = p;
kn->kn_flags |= EV_CLEAR; /* automatically set */
/* XXX lock the proc here while adding to the list? */
SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
return (0);
}
static void
filt_sigdetach(struct knote *kn)
{
struct proc *p = kn->kn_ptr.p_proc;
SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
}
/*
* 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);
}