/*-
* Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* 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. 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 8.14 (Berkeley) 5/14/95
*/
/*
* Manipulate signal mask. Note that we receive new mask, not pointer, and
* return old mask as return value; the library stub does the rest.
*/
int
sys___sigprocmask14(struct lwp *l, const struct sys___sigprocmask14_args *uap,
register_t *retval)
{
/* {
syscallarg(int) how;
syscallarg(const sigset_t *) set;
syscallarg(sigset_t *) oset;
} */
struct proc *p = l->l_proc;
sigset_t nss, oss;
int error;
/*
* 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.
*/
int
sys___sigsuspend14(struct lwp *l, const struct sys___sigsuspend14_args *uap,
register_t *retval)
{
/* {
syscallarg(const sigset_t *) set;
} */
sigset_t ss;
int error;
int
kill1(struct lwp *l, pid_t pid, ksiginfo_t *ksi, register_t *retval)
{
int error;
struct proc *p;
if ((u_int)ksi->ksi_signo >= NSIG)
return EINVAL;
if (pid != l->l_proc->p_pid) {
if (ksi->ksi_pid != l->l_proc->p_pid)
return EPERM;
if (ksi->ksi_uid != kauth_cred_geteuid(l->l_cred))
return EPERM;
switch (ksi->ksi_code) {
case SI_USER:
case SI_QUEUE:
break;
default:
return EPERM;
}
}
if (pid > 0) {
/* kill single process */
mutex_enter(&proc_lock);
p = proc_find_raw(pid);
if (p == NULL || (p->p_stat != SACTIVE && p->p_stat != SSTOP)) {
mutex_exit(&proc_lock);
/* IEEE Std 1003.1-2001: return success for zombies */
return p ? 0 : ESRCH;
}
mutex_enter(p->p_lock);
error = kauth_authorize_process(l->l_cred,
KAUTH_PROCESS_SIGNAL, p, KAUTH_ARG(ksi->ksi_signo),
NULL, NULL);
if (!error && ksi->ksi_signo) {
error = kpsignal2(p, ksi);
}
mutex_exit(p->p_lock);
mutex_exit(&proc_lock);
return error;
}
switch (pid) {
case -1: /* broadcast signal */
return killpg1(l, ksi, 0, 1);
case 0: /* signal own process group */
return killpg1(l, ksi, 0, 0);
default: /* negative explicit process group */
if (pid <= INT_MIN)
return ESRCH;
return killpg1(l, ksi, -pid, 0);
}
/* NOTREACHED */
}
error = copyin(SCARG(uap, ucp), &uc, sizeof (uc));
if (error)
return error;
if ((uc.uc_flags & _UC_CPU) == 0)
return EINVAL;
mutex_enter(p->p_lock);
error = setucontext(l, &uc);
mutex_exit(p->p_lock);
if (error)
return error;
return EJUSTRETURN;
}
/*
* sigtimedwait(2) system call, used also for implementation
* of sigwaitinfo() and sigwait().
*
* This only handles single LWP in signal wait. libpthread provides
* its own sigtimedwait() wrapper to DTRT WRT individual threads.
*/
int
sys_____sigtimedwait50(struct lwp *l,
const struct sys_____sigtimedwait50_args *uap, register_t *retval)
{
int
sigaction1(struct lwp *l, int signum, const struct sigaction *nsa,
struct sigaction *osa, const void *tramp, int vers)
{
struct proc *p;
struct sigacts *ps;
sigset_t tset;
int prop, error;
ksiginfoq_t kq;
static bool v0v1valid;
if (signum <= 0 || signum >= NSIG)
return EINVAL;
p = l->l_proc;
error = 0;
ksiginfo_queue_init(&kq);
/*
* Trampoline ABI version __SIGTRAMP_SIGCODE_VERSION (0) is reserved
* for the legacy kernel provided on-stack trampoline. Conversely,
* if we are using a non-0 ABI version, we must have a trampoline.
* Only validate the vers if a new sigaction was supplied and there
* was an actual handler specified (not SIG_IGN or SIG_DFL), which
* don't require a trampoline. Emulations use legacy kernel
* trampolines with version 0, alternatively check for that too.
*
* If version < __SIGTRAMP_SIGINFO_VERSION_MIN (usually 2), we try
* to autoload the compat module. Note that we interlock with the
* unload check in compat_modcmd() using kernconfig_lock. If the
* autoload fails, we don't try it again for this process.
*/
if (nsa != NULL && nsa->sa_handler != SIG_IGN
&& nsa->sa_handler != SIG_DFL) {
if (__predict_false(vers < __SIGTRAMP_SIGINFO_VERSION_MIN)) {
if (vers == __SIGTRAMP_SIGCODE_VERSION &&
p->p_sigctx.ps_sigcode != NULL) {
/*
* if sigcode is used for this emulation,
* version 0 is allowed.
*/
}
#ifdef __HAVE_STRUCT_SIGCONTEXT
else if (p->p_flag & PK_32) {
/*
* The 32-bit compat module will have
* pre-validated this for us.
*/
v0v1valid = true;
} else if ((p->p_lflag & PL_SIGCOMPAT) == 0) {
kernconfig_lock();
(void)module_autoload("compat_16",
MODULE_CLASS_ANY);
if (sendsig_sigcontext_16_hook.hooked) {
/*
* We need to remember if the
* sigcontext method may be useable,
* because libc may use it even
* if siginfo is available.
*/
v0v1valid = true;
}
mutex_enter(&proc_lock);
/*
* Prevent unload of compat module while
* this process remains.
*/
p->p_lflag |= PL_SIGCOMPAT;
mutex_exit(&proc_lock);
kernconfig_unlock();
}
#endif /* __HAVE_STRUCT_SIGCONTEXT */
}
if ((prop & SA_NORESET) != 0)
SIGACTION_PS(ps, signum).sa_flags &= ~SA_RESETHAND;
if (signum == SIGCHLD) {
if (nsa->sa_flags & SA_NOCLDSTOP)
p->p_sflag |= PS_NOCLDSTOP;
else
p->p_sflag &= ~PS_NOCLDSTOP;
if (nsa->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_flag &= ~PK_NOCLDWAIT;
else
p->p_flag |= PK_NOCLDWAIT;
} else
p->p_flag &= ~PK_NOCLDWAIT;
if (nsa->sa_handler == SIG_IGN) {
/*
* Paranoia: same as above.
*/
if (p->p_pid == 1)
p->p_flag &= ~PK_CLDSIGIGN;
else
p->p_flag |= PK_CLDSIGIGN;
} else
p->p_flag &= ~PK_CLDSIGIGN;
}
/*
* Set bit in p_sigctx.ps_sigignore for signals that are set to
* SIG_IGN, and for signals set to SIG_DFL where the default is to
* ignore. However, don't put SIGCONT in p_sigctx.ps_sigignore, as
* we have to restart the process.
*/
if (nsa->sa_handler == SIG_IGN ||
(nsa->sa_handler == SIG_DFL && (prop & SA_IGNORE) != 0)) {
/* Never to be seen again. */
sigemptyset(&tset);
sigaddset(&tset, signum);
sigclearall(p, &tset, &kq);
if (signum != SIGCONT) {
/* Easier in psignal */
sigaddset(&p->p_sigctx.ps_sigignore, signum);
}
sigdelset(&p->p_sigctx.ps_sigcatch, signum);
} else {
sigdelset(&p->p_sigctx.ps_sigignore, signum);
if (nsa->sa_handler == SIG_DFL)
sigdelset(&p->p_sigctx.ps_sigcatch, signum);
else
sigaddset(&p->p_sigctx.ps_sigcatch, signum);
}
/*
* Previously held signals may now have become visible. Ensure that
* we check for them before returning to userspace.
*/
if (sigispending(l, 0)) {
lwp_lock(l);
l->l_flag |= LW_PENDSIG;
lwp_need_userret(l);
lwp_unlock(l);
}
out:
mutex_exit(p->p_lock);
ksiginfo_queue_drain(&kq);
return error;
}
int
sigprocmask1(struct lwp *l, int how, const sigset_t *nss, sigset_t *oss)
{
sigset_t *mask = &l->l_sigmask;
bool more;
KASSERT(mutex_owned(l->l_proc->p_lock));
if (oss) {
*oss = *mask;
}
if (nss == NULL) {
return 0;
}
switch (how) {
case SIG_BLOCK:
sigplusset(nss, mask);
more = false;
break;
case SIG_UNBLOCK:
sigminusset(nss, mask);
more = true;
break;
case SIG_SETMASK:
*mask = *nss;
more = true;
break;
default:
return EINVAL;
}
sigminusset(&sigcantmask, mask);
if (more && sigispending(l, 0)) {
/*
* Check for pending signals on return to user.
*/
lwp_lock(l);
l->l_flag |= LW_PENDSIG;
lwp_need_userret(l);
lwp_unlock(l);
}
return 0;
}
/*
* When returning from sigsuspend/pselect/pollts, we want
* the old mask to be restored after the
* signal handler has finished. Thus, we
* save it here and mark the sigctx structure
* to indicate this.
*/
mutex_enter(p->p_lock);
l->l_sigrestore = 1;
l->l_sigoldmask = l->l_sigmask;
l->l_sigmask = *ss;
sigminusset(&sigcantmask, &l->l_sigmask);
/* Check for pending signals when sleeping. */
if (sigispending(l, 0)) {
lwp_lock(l);
l->l_flag |= LW_PENDSIG;
lwp_need_userret(l);
lwp_unlock(l);
}
mutex_exit(p->p_lock);
}
/*
* Calculate timeout, if it was specified.
*
* NULL pointer means an infinite timeout.
* {.tv_sec = 0, .tv_nsec = 0} means do not block.
*/
if (SCARG(uap, timeout)) {
error = (*fetchts)(SCARG(uap, timeout), &ts, sizeof(ts));
if (error)
return error;
if ((error = itimespecfix(&ts)) != 0)
return error;
timo = tstohz(&ts);
if (timo == 0) {
if (ts.tv_sec == 0 && ts.tv_nsec == 0)
timo = -1; /* do not block */
else
timo = 1; /* the shortest possible timeout */
}
/*
* Remember current uptime, it would be used in
* ECANCELED/ERESTART case.
*/
getnanouptime(&tsstart);
} else {
memset(&tsstart, 0, sizeof(tsstart)); /* XXXgcc */
timo = 0; /* infinite timeout */
}
error = (*fetchss)(SCARG(uap, set), &l->l_sigwaitset,
sizeof(l->l_sigwaitset));
if (error)
return error;
/*
* Silently ignore SA_CANTMASK signals. psignal1() would ignore
* SA_CANTMASK signals in waitset, we do this only for the below
* siglist check.
*/
sigminusset(&sigcantmask, &l->l_sigwaitset);
memset(&ksi.ksi_info, 0, sizeof(ksi.ksi_info));
mutex_enter(p->p_lock);
/* Check for pending signals in the process, if no - then in LWP. */
if ((signum = sigget(&p->p_sigpend, &ksi, 0, &l->l_sigwaitset)) == 0)
signum = sigget(&l->l_sigpend, &ksi, 0, &l->l_sigwaitset);
if (signum != 0) {
/* If found a pending signal, just copy it out to the user. */
mutex_exit(p->p_lock);
goto out;
}
if (timo < 0) {
/* If not allowed to block, return an error */
mutex_exit(p->p_lock);
return EAGAIN;
}
/*
* Set up the sigwait list and wait for signal to arrive.
* We can either be woken up or time out.
*/
l->l_sigwaited = &ksi;
LIST_INSERT_HEAD(&p->p_sigwaiters, l, l_sigwaiter);
error = cv_timedwait_sig(&l->l_sigcv, p->p_lock, timo);
/*
* Need to find out if we woke as a result of _lwp_wakeup() or a
* signal outside our wait set.
*/
if (l->l_sigwaited != NULL) {
if (error == EINTR) {
/* Wakeup via _lwp_wakeup(). */
error = ECANCELED;
} else if (!error) {
/* Spurious wakeup - arrange for syscall restart. */
error = ERESTART;
}
l->l_sigwaited = NULL;
LIST_REMOVE(l, l_sigwaiter);
}
mutex_exit(p->p_lock);
/*
* If the sleep was interrupted (either by signal or wakeup), update
* the timeout and copyout new value back. It would be used when
* the syscall would be restarted or called again.
*/
if (timo && (error == ERESTART || error == ECANCELED)) {
getnanouptime(&tsnow);
/* Compute how much time has passed since start. */
timespecsub(&tsnow, &tsstart, &tsnow);
/* Subtract passed time from timeout. */
timespecsub(&ts, &tsnow, &ts);
if (ts.tv_sec < 0)
error = EAGAIN;
else {
/* Copy updated timeout to userland. */
error = (*storets)(&ts, SCARG(uap, timeout),
sizeof(ts));
}
}
out:
/*
* If a signal from the wait set arrived, copy it to userland.
* Copy only the used part of siginfo, the padding part is
* left unchanged (userland is not supposed to touch it anyway).
*/
if (error == 0 && SCARG(uap, info)) {
error = (*storeinf)(&ksi.ksi_info, SCARG(uap, info),
sizeof(ksi.ksi_info));
}
if (error == 0) {
*retval = ksi.ksi_info._signo;
SDT_PROBE(proc, kernel, , signal__clear, *retval,
&ksi, 0, 0, 0);
}
return error;
}
