[apple/xnu.git] / bsd / kern / mach_process.c

/*
 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*-
 * Copyright (c) 1982, 1986, 1989, 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.
 *
 *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
 */

#include <machine/reg.h>
#include <machine/psl.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/errno.h>
#include <sys/ptrace.h>
#include <sys/uio.h>
#include <sys/user.h>
#include <sys/sysctl.h>
#include <sys/wait.h>

#include <sys/mount_internal.h>
#include <sys/sysproto.h>

#include <bsm/audit_kernel.h>

#include <kern/task.h>
#include <kern/thread.h>

#include <mach/task.h>			/* for task_resume() */
#include <kern/sched_prim.h>		/* for thread_exception_return() */

/* XXX ken/bsd_kern.c - prototype should be in common header */
int get_task_userstop(task_t);

/* Macros to clear/set/test flags. */
#define	SET(t, f)	(t) |= (f)
#define	CLR(t, f)	(t) &= ~(f)
#define	ISSET(t, f)	((t) & (f))

extern thread_t	port_name_to_thread(mach_port_name_t port_name);
extern thread_t get_firstthread(task_t);


/*
 * sys-trace system call.
 */

int
ptrace(struct proc *p, struct ptrace_args *uap, register_t *retval)
{
	struct proc *t = current_proc();	/* target process */
	task_t		task;
	thread_t	th_act;
	struct uthread 	*ut;
	int tr_sigexc = 0;
	int error = 0;
	int stopped = 0;

	AUDIT_ARG(cmd, uap->req);
	AUDIT_ARG(pid, uap->pid);
	AUDIT_ARG(addr, uap->addr);
	AUDIT_ARG(value, uap->data);

	if (uap->req == PT_DENY_ATTACH) {
		proc_lock(p);
		if (ISSET(p->p_lflag, P_LTRACED)) {
			proc_unlock(p);
			exit1(p, W_EXITCODE(ENOTSUP, 0), retval);
			/* drop funnel before we return */
			thread_exception_return();
			/* NOTREACHED */
		}
		SET(p->p_lflag, P_LNOATTACH);
		proc_unlock(p);

		return(0);
	}

	if (uap->req == PT_FORCEQUOTA) {
		if (is_suser()) {
			OSBitOrAtomic(P_FORCEQUOTA, (UInt32 *)&t->p_flag);
			return (0);
		} else
			return (EPERM);
	}

	/*
	 *	Intercept and deal with "please trace me" request.
	 */	 
	if (uap->req == PT_TRACE_ME) {
		proc_lock(p);
		SET(p->p_lflag, P_LTRACED);
		/* Non-attached case, our tracer is our parent. */
		p->p_oppid = p->p_ppid;
		proc_unlock(p);
		return(0);
	}
	if (uap->req == PT_SIGEXC) {
		proc_lock(p);
		if (ISSET(p->p_lflag, P_LTRACED)) {
			SET(p->p_lflag, P_LSIGEXC);
			proc_unlock(p);
			return(0);
		} else {
			proc_unlock(p);
			return(EINVAL);
		}
	}

	/* 
	 * We do not want ptrace to do anything with kernel or launchd 
	 */
	if (uap->pid < 2) {
		return(EPERM);
	}

	/*
	 *	Locate victim, and make sure it is traceable.
	 */
	if ((t = proc_find(uap->pid)) == NULL)
			return (ESRCH);

	AUDIT_ARG(process, t);

	task = t->task;
	if (uap->req == PT_ATTACHEXC) {
		uap->req = PT_ATTACH;
		tr_sigexc = 1;
	}
	if (uap->req == PT_ATTACH) {
		int		err;
		
		if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE, 
									 t, (uintptr_t)&err, 0, 0) == 0 ) {
			/* it's OK to attach */
			proc_lock(t);
			SET(t->p_lflag, P_LTRACED);
			if (tr_sigexc) 
				SET(t->p_lflag, P_LSIGEXC);
	
			t->p_oppid = t->p_ppid;
			proc_unlock(t);
			if (t->p_pptr != p)
				proc_reparentlocked(t, p, 1, 0);
	
			proc_lock(t);
			if (get_task_userstop(task) > 0 ) {
				stopped = 1;
			}
			t->p_xstat = 0;
			proc_unlock(t);
			psignal(t, SIGSTOP);
			/*
			 * If the process was stopped, wake up and run through
			 * issignal() again to properly connect to the tracing
			 * process.
			 */
			if (stopped)
				task_resume(task);       
			error = 0;
			goto out;
		}
		else {
			/* not allowed to attach, proper error code returned by kauth_authorize_process */
			if (ISSET(t->p_lflag, P_LNOATTACH)) {
				psignal(p, SIGSEGV);
			}
			
			error = err;
			goto out;
		}
	}

	/*
	 * You can't do what you want to the process if:
	 *	(1) It's not being traced at all,
	 */
	proc_lock(t);
	if (!ISSET(t->p_lflag, P_LTRACED)) {
		proc_unlock(t);
		error = EPERM;
		goto out;
	}

	/*
	 *	(2) it's not being traced by _you_, or
	 */
	if (t->p_pptr != p) {
		proc_unlock(t);
		error = EBUSY;
		goto out;
	}

	/*
	 *	(3) it's not currently stopped.
	 */
	if (t->p_stat != SSTOP) {
		proc_unlock(t);
		error = EBUSY;
		goto out;
	}

	/*
	 *	Mach version of ptrace executes request directly here,
	 *	thus simplifying the interaction of ptrace and signals.
	 */
	/* proc lock is held here */
	switch (uap->req) {

	case PT_DETACH:
		if (t->p_oppid != t->p_ppid) {
			struct proc *pp;

			proc_unlock(t);
			pp = proc_find(t->p_oppid);
			proc_reparentlocked(t, pp ? pp : initproc, 1, 0);
			if (pp != PROC_NULL)
				proc_rele(pp);
			proc_lock(t);
			
		}

		t->p_oppid = 0;
		CLR(t->p_lflag, P_LTRACED);
		CLR(t->p_lflag, P_LSIGEXC);
		proc_unlock(t);
		goto resume;
		
	case PT_KILL:
		/*
		 *	Tell child process to kill itself after it
		 *	is resumed by adding NSIG to p_cursig. [see issig]
		 */
		proc_unlock(t);
		psignal(t, SIGKILL);
		goto resume;

	case PT_STEP:			/* single step the child */
	case PT_CONTINUE:		/* continue the child */
		proc_unlock(t);
		th_act = (thread_t)get_firstthread(task);
		if (th_act == THREAD_NULL) {
			error = EINVAL;
			goto out;
		}

		if (uap->addr != (user_addr_t)1) {
#if defined(ppc)
#define ALIGNED(addr,size)	(((unsigned)(addr)&((size)-1))==0)
			if (!ALIGNED((int)uap->addr, sizeof(int)))
				return (ERESTART);
#undef 	ALIGNED
#endif
			thread_setentrypoint(th_act, uap->addr);
		}

		if ((unsigned)uap->data >= NSIG) {
			error = EINVAL;
			goto out;
		}

		if (uap->data != 0) {
			psignal(t, uap->data);
                }

		if (uap->req == PT_STEP) {
		        /*
			 * set trace bit
			 */
			if (thread_setsinglestep(th_act, 1) != KERN_SUCCESS) {
				error = ENOTSUP;
				goto out;
			}
		} else {
		        /*
			 * clear trace bit if on
			 */
			if (thread_setsinglestep(th_act, 0) != KERN_SUCCESS) {
				error = ENOTSUP;
				goto out;
			}
		}	
	resume:
		proc_lock(t);
		t->p_xstat = uap->data;
		t->p_stat = SRUN;
		if (t->sigwait) {
			wakeup((caddr_t)&(t->sigwait));
			proc_unlock(t);
			if ((t->p_lflag & P_LSIGEXC) == 0) {
				task_resume(task);
			}
		} else
			proc_unlock(t);
			
		break;
		
	case PT_THUPDATE:  {
		proc_unlock(t);
		if ((unsigned)uap->data >= NSIG) {
			error = EINVAL;
			goto out;
		}
		th_act = port_name_to_thread(CAST_DOWN(mach_port_name_t, uap->addr));
		if (th_act == THREAD_NULL)
			return (ESRCH);
		ut = (uthread_t)get_bsdthread_info(th_act);
		if (uap->data)
			ut->uu_siglist |= sigmask(uap->data);
		proc_lock(t);
		t->p_xstat = uap->data;
		t->p_stat = SRUN;
		proc_unlock(t);
		thread_deallocate(th_act);
		error = 0;
		}
		break;
	default:
		proc_unlock(t);
		error = EINVAL;
		goto out;
	}

	error = 0;
out:
	proc_rele(t);
	return(error);
}


/*
 * determine if one process (cur_procp) can trace another process (traced_procp).
 */

int
cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
{
	int		my_err;
	/*
	 * You can't trace a process if:
	 *	(1) it's the process that's doing the tracing,
	 */
	if (traced_procp->p_pid == cur_procp->p_pid) {
		*errp = EINVAL;
		return (0);
	}

	/*
	 *	(2) it's already being traced, or
	 */
	if (ISSET(traced_procp->p_lflag, P_LTRACED)) {
		*errp = EBUSY;
		return (0);
	}

	/*
	 *	(3) it's not owned by you, or is set-id on exec
	 *	    (unless you're root).
	 */
	if ((creds->cr_ruid != proc_ucred(traced_procp)->cr_ruid ||
		ISSET(traced_procp->p_flag, P_SUGID)) &&
		(my_err = suser(creds, &cur_procp->p_acflag)) != 0) {
		*errp = my_err;
		return (0);
	}

	if ((cur_procp->p_lflag & P_LTRACED) && isinferior(cur_procp, traced_procp)) {
		*errp = EPERM;
		return (0);
	}

	if (ISSET(traced_procp->p_lflag, P_LNOATTACH)) {
		*errp = EBUSY;
		return (0);
	}
	return(1);
}
Commit	Line	Data
1c79356b	1	/*
2d21ac55	2	* Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
5d5c5d0d	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	29	/*-
	30	* Copyright (c) 1982, 1986, 1989, 1993
	31	* The Regents of the University of California. All rights reserved.
	32	* (c) UNIX System Laboratories, Inc.
	33	* All or some portions of this file are derived from material licensed
	34	* to the University of California by American Telephone and Telegraph
	35	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	36	* the permission of UNIX System Laboratories, Inc.
	37	*
	38	* Redistribution and use in source and binary forms, with or without
	39	* modification, are permitted provided that the following conditions
	40	* are met:
	41	* 1. Redistributions of source code must retain the above copyright
	42	* notice, this list of conditions and the following disclaimer.
	43	* 2. Redistributions in binary form must reproduce the above copyright
	44	* notice, this list of conditions and the following disclaimer in the
	45	* documentation and/or other materials provided with the distribution.
	46	* 3. All advertising materials mentioning features or use of this software
	47	* must display the following acknowledgement:
	48	* This product includes software developed by the University of
	49	* California, Berkeley and its contributors.
	50	* 4. Neither the name of the University nor the names of its contributors
	51	* may be used to endorse or promote products derived from this software
	52	* without specific prior written permission.
	53	*
	54	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	55	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	56	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	57	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	58	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	59	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	60	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	61	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	62	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	63	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	64	* SUCH DAMAGE.
	65	*
	66	* from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93
	67	*/
1c79356b A	68
	69	#include <machine/reg.h>
	70	#include <machine/psl.h>
	71
	72	#include <sys/param.h>
	73	#include <sys/systm.h>
91447636 A	74	#include <sys/proc_internal.h>
91447636 A	75	#include <sys/kauth.h>
1c79356b A	76	#include <sys/errno.h>
	77	#include <sys/ptrace.h>
	78	#include <sys/uio.h>
	79	#include <sys/user.h>
	80	#include <sys/sysctl.h>
0b4e3aa0	81	#include <sys/wait.h>
1c79356b	82
91447636 A	83	#include <sys/mount_internal.h>
91447636 A	84	#include <sys/sysproto.h>
1c79356b	85
e5568f75 A	86	#include <bsm/audit_kernel.h>
e5568f75 A	87
1c79356b A	88	#include <kern/task.h>
1c79356b A	89	#include <kern/thread.h>
1c79356b	90
2d21ac55 A	91	#include <mach/task.h> /* for task_resume() */
	92	#include <kern/sched_prim.h> /* for thread_exception_return() */
	93
	94	/* XXX ken/bsd_kern.c - prototype should be in common header */
	95	int get_task_userstop(task_t);
91447636	96
1c79356b A	97	/* Macros to clear/set/test flags. */
	98	#define SET(t, f) (t) \|= (f)
	99	#define CLR(t, f) (t) &= ~(f)
	100	#define ISSET(t, f) ((t) & (f))
	101
91447636	102	extern thread_t port_name_to_thread(mach_port_name_t port_name);
91447636 A	103	extern thread_t get_firstthread(task_t);
91447636 A	104
9bccf70c	105
1c79356b A	106	/*
	107	* sys-trace system call.
	108	*/
9bccf70c	109
1c79356b	110	int
2d21ac55	111	ptrace(struct proc p, struct ptrace_args uap, register_t *retval)
1c79356b A	112	{
1c79356b A	113	struct proc t = current_proc(); / target process */
1c79356b	114	task_t task;
91447636	115	thread_t th_act;
1c79356b	116	struct uthread *ut;
9bccf70c	117	int tr_sigexc = 0;
2d21ac55 A	118	int error = 0;
2d21ac55 A	119	int stopped = 0;
1c79356b	120
e5568f75 A	121	AUDIT_ARG(cmd, uap->req);
	122	AUDIT_ARG(pid, uap->pid);
	123	AUDIT_ARG(addr, uap->addr);
	124	AUDIT_ARG(value, uap->data);
1c79356b	125
91447636	126	if (uap->req == PT_DENY_ATTACH) {
2d21ac55 A	127	proc_lock(p);
	128	if (ISSET(p->p_lflag, P_LTRACED)) {
	129	proc_unlock(p);
91447636 A	130	exit1(p, W_EXITCODE(ENOTSUP, 0), retval);
91447636 A	131	/* drop funnel before we return */
91447636 A	132	thread_exception_return();
	133	/* NOTREACHED */
	134	}
2d21ac55 A	135	SET(p->p_lflag, P_LNOATTACH);
2d21ac55 A	136	proc_unlock(p);
0b4e3aa0 A	137
	138	return(0);
	139	}
	140
9bccf70c A	141	if (uap->req == PT_FORCEQUOTA) {
9bccf70c A	142	if (is_suser()) {
2d21ac55	143	OSBitOrAtomic(P_FORCEQUOTA, (UInt32 *)&t->p_flag);
9bccf70c A	144	return (0);
	145	} else
	146	return (EPERM);
	147	}
	148
1c79356b A	149	/*
	150	* Intercept and deal with "please trace me" request.
	151	*/
	152	if (uap->req == PT_TRACE_ME) {
2d21ac55 A	153	proc_lock(p);
2d21ac55 A	154	SET(p->p_lflag, P_LTRACED);
1c79356b	155	/* Non-attached case, our tracer is our parent. */
2d21ac55 A	156	p->p_oppid = p->p_ppid;
2d21ac55 A	157	proc_unlock(p);
1c79356b A	158	return(0);
1c79356b A	159	}
9bccf70c	160	if (uap->req == PT_SIGEXC) {
2d21ac55 A	161	proc_lock(p);
	162	if (ISSET(p->p_lflag, P_LTRACED)) {
	163	SET(p->p_lflag, P_LSIGEXC);
	164	proc_unlock(p);
9bccf70c	165	return(0);
2d21ac55 A	166	} else {
2d21ac55 A	167	proc_unlock(p);
9bccf70c	168	return(EINVAL);
2d21ac55 A	169	}
	170	}
	171
	172	/*
	173	* We do not want ptrace to do anything with kernel or launchd
	174	*/
	175	if (uap->pid < 2) {
	176	return(EPERM);
9bccf70c	177	}
1c79356b A	178
	179	/*
	180	* Locate victim, and make sure it is traceable.
	181	*/
2d21ac55	182	if ((t = proc_find(uap->pid)) == NULL)
1c79356b A	183	return (ESRCH);
1c79356b A	184
e5568f75 A	185	AUDIT_ARG(process, t);
e5568f75 A	186
1c79356b	187	task = t->task;
9bccf70c A	188	if (uap->req == PT_ATTACHEXC) {
	189	uap->req = PT_ATTACH;
	190	tr_sigexc = 1;
	191	}
1c79356b	192	if (uap->req == PT_ATTACH) {
91447636 A	193	int err;
	194
	195	if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE,
	196	t, (uintptr_t)&err, 0, 0) == 0 ) {
	197	/* it's OK to attach */
2d21ac55 A	198	proc_lock(t);
2d21ac55 A	199	SET(t->p_lflag, P_LTRACED);
91447636	200	if (tr_sigexc)
2d21ac55	201	SET(t->p_lflag, P_LSIGEXC);
91447636	202
2d21ac55 A	203	t->p_oppid = t->p_ppid;
2d21ac55 A	204	proc_unlock(t);
91447636	205	if (t->p_pptr != p)
2d21ac55	206	proc_reparentlocked(t, p, 1, 0);
91447636	207
2d21ac55 A	208	proc_lock(t);
	209	if (get_task_userstop(task) > 0 ) {
	210	stopped = 1;
91447636	211	}
2d21ac55 A	212	t->p_xstat = 0;
	213	proc_unlock(t);
	214	psignal(t, SIGSTOP);
	215	/*
	216	* If the process was stopped, wake up and run through
	217	* issignal() again to properly connect to the tracing
	218	* process.
	219	*/
	220	if (stopped)
	221	task_resume(task);
	222	error = 0;
	223	goto out;
0b4e3aa0	224	}
91447636 A	225	else {
91447636 A	226	/* not allowed to attach, proper error code returned by kauth_authorize_process */
2d21ac55	227	if (ISSET(t->p_lflag, P_LNOATTACH)) {
91447636 A	228	psignal(p, SIGSEGV);
91447636 A	229	}
2d21ac55 A	230
	231	error = err;
	232	goto out;
1c79356b	233	}
1c79356b A	234	}
	235
	236	/*
	237	* You can't do what you want to the process if:
	238	* (1) It's not being traced at all,
	239	*/
2d21ac55 A	240	proc_lock(t);
	241	if (!ISSET(t->p_lflag, P_LTRACED)) {
	242	proc_unlock(t);
	243	error = EPERM;
	244	goto out;
	245	}
1c79356b A	246
	247	/*
	248	* (2) it's not being traced by _you_, or
	249	*/
2d21ac55 A	250	if (t->p_pptr != p) {
	251	proc_unlock(t);
	252	error = EBUSY;
	253	goto out;
	254	}
1c79356b A	255
	256	/*
	257	* (3) it's not currently stopped.
	258	*/
2d21ac55 A	259	if (t->p_stat != SSTOP) {
	260	proc_unlock(t);
	261	error = EBUSY;
	262	goto out;
	263	}
1c79356b A	264
	265	/*
	266	* Mach version of ptrace executes request directly here,
	267	* thus simplifying the interaction of ptrace and signals.
	268	*/
2d21ac55	269	/* proc lock is held here */
1c79356b A	270	switch (uap->req) {
	271
	272	case PT_DETACH:
2d21ac55	273	if (t->p_oppid != t->p_ppid) {
1c79356b A	274	struct proc *pp;
1c79356b A	275
2d21ac55 A	276	proc_unlock(t);
	277	pp = proc_find(t->p_oppid);
	278	proc_reparentlocked(t, pp ? pp : initproc, 1, 0);
	279	if (pp != PROC_NULL)
	280	proc_rele(pp);
	281	proc_lock(t);
	282
1c79356b A	283	}
	284
	285	t->p_oppid = 0;
2d21ac55 A	286	CLR(t->p_lflag, P_LTRACED);
	287	CLR(t->p_lflag, P_LSIGEXC);
	288	proc_unlock(t);
1c79356b A	289	goto resume;
	290
	291	case PT_KILL:
	292	/*
	293	* Tell child process to kill itself after it
	294	* is resumed by adding NSIG to p_cursig. [see issig]
	295	*/
2d21ac55 A	296	proc_unlock(t);
2d21ac55 A	297	psignal(t, SIGKILL);
1c79356b A	298	goto resume;
	299
	300	case PT_STEP: /* single step the child */
	301	case PT_CONTINUE: /* continue the child */
2d21ac55	302	proc_unlock(t);
91447636	303	th_act = (thread_t)get_firstthread(task);
2d21ac55 A	304	if (th_act == THREAD_NULL) {
	305	error = EINVAL;
	306	goto out;
	307	}
0c530ab8	308
91447636	309	if (uap->addr != (user_addr_t)1) {
0c530ab8	310	#if defined(ppc)
1c79356b	311	#define ALIGNED(addr,size) (((unsigned)(addr)&((size)-1))==0)
2d21ac55 A	312	if (!ALIGNED((int)uap->addr, sizeof(int)))
2d21ac55 A	313	return (ERESTART);
1c79356b	314	#undef ALIGNED
1c79356b	315	#endif
2d21ac55	316	thread_setentrypoint(th_act, uap->addr);
0c530ab8	317	}
1c79356b	318
2d21ac55 A	319	if ((unsigned)uap->data >= NSIG) {
	320	error = EINVAL;
	321	goto out;
	322	}
1c79356b A	323
1c79356b A	324	if (uap->data != 0) {
2d21ac55	325	psignal(t, uap->data);
1c79356b	326	}
1c79356b A	327
1c79356b A	328	if (uap->req == PT_STEP) {
0c530ab8 A	329	/*
	330	* set trace bit
	331	*/
2d21ac55 A	332	if (thread_setsinglestep(th_act, 1) != KERN_SUCCESS) {
	333	error = ENOTSUP;
	334	goto out;
	335	}
0c530ab8 A	336	} else {
	337	/*
	338	* clear trace bit if on
	339	*/
2d21ac55 A	340	if (thread_setsinglestep(th_act, 0) != KERN_SUCCESS) {
	341	error = ENOTSUP;
	342	goto out;
	343	}
	344	}
1c79356b	345	resume:
2d21ac55	346	proc_lock(t);
1c79356b A	347	t->p_xstat = uap->data;
	348	t->p_stat = SRUN;
	349	if (t->sigwait) {
	350	wakeup((caddr_t)&(t->sigwait));
2d21ac55 A	351	proc_unlock(t);
	352	if ((t->p_lflag & P_LSIGEXC) == 0) {
	353	task_resume(task);
	354	}
	355	} else
	356	proc_unlock(t);
	357
1c79356b A	358	break;
1c79356b A	359
9bccf70c	360	case PT_THUPDATE: {
2d21ac55 A	361	proc_unlock(t);
	362	if ((unsigned)uap->data >= NSIG) {
	363	error = EINVAL;
	364	goto out;
	365	}
91447636 A	366	th_act = port_name_to_thread(CAST_DOWN(mach_port_name_t, uap->addr));
91447636 A	367	if (th_act == THREAD_NULL)
9bccf70c A	368	return (ESRCH);
	369	ut = (uthread_t)get_bsdthread_info(th_act);
	370	if (uap->data)
	371	ut->uu_siglist \|= sigmask(uap->data);
2d21ac55	372	proc_lock(t);
9bccf70c A	373	t->p_xstat = uap->data;
9bccf70c A	374	t->p_stat = SRUN;
2d21ac55	375	proc_unlock(t);
91447636	376	thread_deallocate(th_act);
2d21ac55	377	error = 0;
9bccf70c A	378	}
9bccf70c A	379	break;
1c79356b	380	default:
2d21ac55 A	381	proc_unlock(t);
	382	error = EINVAL;
	383	goto out;
1c79356b	384	}
9bccf70c	385
2d21ac55 A	386	error = 0;
	387	out:
	388	proc_rele(t);
	389	return(error);
1c79356b A	390	}
1c79356b A	391
91447636 A	392
	393	/*
	394	* determine if one process (cur_procp) can trace another process (traced_procp).
	395	*/
	396
	397	int
	398	cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
	399	{
	400	int my_err;
	401	/*
	402	* You can't trace a process if:
	403	* (1) it's the process that's doing the tracing,
	404	*/
	405	if (traced_procp->p_pid == cur_procp->p_pid) {
	406	*errp = EINVAL;
	407	return (0);
	408	}
	409
	410	/*
	411	* (2) it's already being traced, or
	412	*/
2d21ac55	413	if (ISSET(traced_procp->p_lflag, P_LTRACED)) {
91447636 A	414	*errp = EBUSY;
	415	return (0);
	416	}
	417
	418	/*
	419	* (3) it's not owned by you, or is set-id on exec
	420	* (unless you're root).
	421	*/
	422	if ((creds->cr_ruid != proc_ucred(traced_procp)->cr_ruid \|\|
	423	ISSET(traced_procp->p_flag, P_SUGID)) &&
	424	(my_err = suser(creds, &cur_procp->p_acflag)) != 0) {
	425	*errp = my_err;
	426	return (0);
	427	}
	428
2d21ac55	429	if ((cur_procp->p_lflag & P_LTRACED) && isinferior(cur_procp, traced_procp)) {
91447636 A	430	*errp = EPERM;
	431	return (0);
	432	}
	433
2d21ac55	434	if (ISSET(traced_procp->p_lflag, P_LNOATTACH)) {
91447636 A	435	*errp = EBUSY;
	436	return (0);
	437	}
	438	return(1);
	439	}