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

/*
 * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This 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 OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_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/machine/thread_status.h>


/* 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 kern_return_t thread_getstatus(thread_t thread, int flavor, thread_state_t tstate, mach_msg_type_number_t *count);
extern thread_t get_firstthread(task_t);

#if defined (ppc)
extern kern_return_t thread_setstatus(thread_t thread, int flavor, thread_state_t tstate, mach_msg_type_number_t count);
#endif

/*
 * sys-trace system call.
 */

int
ptrace(p, uap, retval)
	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		*locr0;
#if defined(ppc)
	struct ppc_thread_state64 statep;
#elif	defined(i386)
	struct i386_saved_state statep;
#else
#error architecture not supported
#endif
	unsigned long state_count;
	int tr_sigexc = 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) {
		if (ISSET(p->p_flag, P_TRACED)) {
			exit1(p, W_EXITCODE(ENOTSUP, 0), retval);
			/* drop funnel before we return */
			thread_funnel_set(kernel_flock, FALSE);
			thread_exception_return();
			/* NOTREACHED */
		}
		SET(p->p_flag, P_NOATTACH);

		return(0);
	}

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

	/*
	 *	Intercept and deal with "please trace me" request.
	 */	 
	if (uap->req == PT_TRACE_ME) {
		SET(p->p_flag, P_TRACED);
		/* Non-attached case, our tracer is our parent. */
		t->p_oppid = t->p_pptr->p_pid;
		return(0);
	}
	if (uap->req == PT_SIGEXC) {
		if (ISSET(p->p_flag, P_TRACED)) {
			SET(p->p_flag, P_SIGEXC);
			return(0);
		} else
			return(EINVAL);
	}

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

	AUDIT_ARG(process, t);

	/* We do not want ptrace to do anything with kernel, init 
	 * and mach_init
	 */
	if (uap->pid <=2 )
		return (EPERM);

	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 */
			SET(t->p_flag, P_TRACED);
			if (tr_sigexc) 
				SET(t->p_flag, P_SIGEXC);
	
			t->p_oppid = t->p_pptr->p_pid;
			if (t->p_pptr != p)
				proc_reparent(t, p);
	
			if (get_task_userstop(task) == 0 ) {
				t->p_xstat = 0;
				psignal(t, SIGSTOP);
			} else {
				t->p_xstat = SIGSTOP; 
				task_resume(task);       
			}
			return(0);
		}
		else {
			/* not allowed to attach, proper error code returned by kauth_authorize_process */
			if (ISSET(t->p_flag, P_NOATTACH)) {
				psignal(p, SIGSEGV);
			}
			return (err);
		}
	}

	/*
	 * You can't do what you want to the process if:
	 *	(1) It's not being traced at all,
	 */
	if (!ISSET(t->p_flag, P_TRACED))
		return (EPERM);

	/*
	 *	(2) it's not being traced by _you_, or
	 */
	if (t->p_pptr != p)
		return (EBUSY);

	/*
	 *	(3) it's not currently stopped.
	 */
	if (t->p_stat != SSTOP)
		return (EBUSY);

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

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

			pp = pfind(t->p_oppid);
			proc_reparent(t, pp ? pp : initproc);
		}

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

	case PT_STEP:			/* single step the child */
	case PT_CONTINUE:		/* continue the child */
		th_act = (thread_t)get_firstthread(task);
		if (th_act == THREAD_NULL)
			goto errorLabel;
		ut = (uthread_t)get_bsdthread_info(th_act);
		locr0 = ut->uu_ar0;
#if defined(i386)
		state_count = i386_NEW_THREAD_STATE_COUNT;
		if (thread_getstatus(th_act, i386_NEW_THREAD_STATE, &statep, &state_count)  != KERN_SUCCESS) {
			goto errorLabel;
		}	
#elif defined(ppc)
		state_count = PPC_THREAD_STATE64_COUNT;
		if (thread_getstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, (mach_msg_type_number_t *)&state_count)  != KERN_SUCCESS) {
			goto errorLabel;
		}	
#else
#error architecture not supported
#endif
		if (uap->addr != (user_addr_t)1) {
#if	defined(i386)
			locr0[PC] = (int)uap->addr;
#elif	defined(ppc)
#define ALIGNED(addr,size)	(((unsigned)(addr)&((size)-1))==0)
		if (!ALIGNED((int)uap->addr, sizeof(int)))
			return (ERESTART);

		statep.srr0 = uap->addr;
		state_count = PPC_THREAD_STATE64_COUNT;
		if (thread_setstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, state_count)  != KERN_SUCCESS) {
			goto errorLabel;
		}	
#undef 	ALIGNED
#else
#error architecture not implemented!
#endif
		} /* uap->addr != (user_addr_t)1 */

		if ((unsigned)uap->data >= NSIG)
			goto errorLabel;

		if (uap->data != 0) {
			psignal_lock(t, uap->data, 0);
                }
#if defined(ppc)
		state_count = PPC_THREAD_STATE64_COUNT;
		if (thread_getstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, (mach_msg_type_number_t *)&state_count)  != KERN_SUCCESS) {
			goto errorLabel;
		}	
#endif

#define MSR_SE_BIT	21

		if (uap->req == PT_STEP) {
#if	defined(i386)
			locr0[PS] |= PSL_T;
#elif 	defined(ppc)
			statep.srr1 |= MASK(MSR_SE);
#else
#error architecture not implemented!
#endif
		} /* uap->req == PT_STEP */
		else {  /* PT_CONTINUE - clear trace bit if set */
#if defined(i386)
			locr0[PS] &= ~PSL_T;
#elif defined(ppc)
			statep.srr1 &= ~MASK(MSR_SE);
#endif
		}
#if defined (ppc)
		state_count = PPC_THREAD_STATE64_COUNT;
		if (thread_setstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, state_count)  != KERN_SUCCESS) {
			goto errorLabel;
		}	
#endif
	resume:
		t->p_xstat = uap->data;
		t->p_stat = SRUN;
		if (t->sigwait) {
			wakeup((caddr_t)&(t->sigwait));
			if ((t->p_flag & P_SIGEXC) == 0)
				task_release(task);
		}
		break;
		
	case PT_THUPDATE:  {
		if ((unsigned)uap->data >= NSIG)
			goto errorLabel;
		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);
		t->p_xstat = uap->data;
		t->p_stat = SRUN;
		thread_deallocate(th_act);
		return(0);
		}
		break;
errorLabel:
	default:
		return(EINVAL);
	}

	return(0);
}


/*
 * 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_flag, P_TRACED)) {
		*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_flag & P_TRACED) && isinferior(cur_procp, traced_procp)) {
		*errp = EPERM;
		return (0);
	}

	if (ISSET(traced_procp->p_flag, P_NOATTACH)) {
		*errp = EBUSY;
		return (0);
	}
	return(1);
}
Commit	Line	Data
1c79356b	1	/*
91447636	2	* Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
1c79356b A	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
e5568f75 A	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
1c79356b	11	*
e5568f75 A	12	* This Original Code and all software distributed under the License are
e5568f75 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
e5568f75 A	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
1c79356b A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	23	/*-
	24	* Copyright (c) 1982, 1986, 1989, 1993
	25	* The Regents of the University of California. All rights reserved.
	26	* (c) UNIX System Laboratories, Inc.
	27	* All or some portions of this file are derived from material licensed
	28	* to the University of California by American Telephone and Telegraph
	29	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	30	* the permission of UNIX System Laboratories, Inc.
	31	*
	32	* Redistribution and use in source and binary forms, with or without
	33	* modification, are permitted provided that the following conditions
	34	* are met:
	35	* 1. Redistributions of source code must retain the above copyright
	36	* notice, this list of conditions and the following disclaimer.
	37	* 2. Redistributions in binary form must reproduce the above copyright
	38	* notice, this list of conditions and the following disclaimer in the
	39	* documentation and/or other materials provided with the distribution.
	40	* 3. All advertising materials mentioning features or use of this software
	41	* must display the following acknowledgement:
	42	* This product includes software developed by the University of
	43	* California, Berkeley and its contributors.
	44	* 4. Neither the name of the University nor the names of its contributors
	45	* may be used to endorse or promote products derived from this software
	46	* without specific prior written permission.
	47	*
	48	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	49	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	50	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	51	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	52	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	53	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	54	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	55	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	56	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	57	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	58	* SUCH DAMAGE.
	59	*
	60	* from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93
	61	*/
1c79356b A	62
	63	#include <machine/reg.h>
	64	#include <machine/psl.h>
	65
	66	#include <sys/param.h>
	67	#include <sys/systm.h>
91447636 A	68	#include <sys/proc_internal.h>
91447636 A	69	#include <sys/kauth.h>
1c79356b A	70	#include <sys/errno.h>
	71	#include <sys/ptrace.h>
	72	#include <sys/uio.h>
	73	#include <sys/user.h>
	74	#include <sys/sysctl.h>
0b4e3aa0	75	#include <sys/wait.h>
1c79356b	76
91447636 A	77	#include <sys/mount_internal.h>
91447636 A	78	#include <sys/sysproto.h>
1c79356b	79
e5568f75 A	80	#include <bsm/audit_kernel.h>
e5568f75 A	81
1c79356b A	82	#include <kern/task.h>
	83	#include <kern/thread.h>
	84	#include <mach/machine/thread_status.h>
	85
91447636	86
1c79356b A	87	/* Macros to clear/set/test flags. */
	88	#define SET(t, f) (t) \|= (f)
	89	#define CLR(t, f) (t) &= ~(f)
	90	#define ISSET(t, f) ((t) & (f))
	91
91447636 A	92	extern thread_t port_name_to_thread(mach_port_name_t port_name);
	93	extern kern_return_t thread_getstatus(thread_t thread, int flavor, thread_state_t tstate, mach_msg_type_number_t *count);
	94	extern thread_t get_firstthread(task_t);
	95
	96	#if defined (ppc)
	97	extern kern_return_t thread_setstatus(thread_t thread, int flavor, thread_state_t tstate, mach_msg_type_number_t count);
	98	#endif
9bccf70c	99
1c79356b A	100	/*
	101	* sys-trace system call.
	102	*/
9bccf70c	103
1c79356b A	104	int
	105	ptrace(p, uap, retval)
	106	struct proc *p;
	107	struct ptrace_args *uap;
	108	register_t *retval;
	109	{
	110	struct proc t = current_proc(); / target process */
1c79356b	111	task_t task;
91447636	112	thread_t th_act;
1c79356b A	113	struct uthread *ut;
1c79356b A	114	int *locr0;
1c79356b	115	#if defined(ppc)
55e303ae	116	struct ppc_thread_state64 statep;
1c79356b A	117	#elif defined(i386)
	118	struct i386_saved_state statep;
	119	#else
	120	#error architecture not supported
	121	#endif
	122	unsigned long state_count;
9bccf70c	123	int tr_sigexc = 0;
1c79356b	124
e5568f75 A	125	AUDIT_ARG(cmd, uap->req);
	126	AUDIT_ARG(pid, uap->pid);
	127	AUDIT_ARG(addr, uap->addr);
	128	AUDIT_ARG(value, uap->data);
1c79356b	129
91447636 A	130	if (uap->req == PT_DENY_ATTACH) {
	131	if (ISSET(p->p_flag, P_TRACED)) {
	132	exit1(p, W_EXITCODE(ENOTSUP, 0), retval);
	133	/* drop funnel before we return */
	134	thread_funnel_set(kernel_flock, FALSE);
	135	thread_exception_return();
	136	/* NOTREACHED */
	137	}
0b4e3aa0 A	138	SET(p->p_flag, P_NOATTACH);
	139
	140	return(0);
	141	}
	142
9bccf70c A	143	if (uap->req == PT_FORCEQUOTA) {
	144	if (is_suser()) {
	145	SET(t->p_flag, P_FORCEQUOTA);
	146	return (0);
	147	} else
	148	return (EPERM);
	149	}
	150
1c79356b A	151	/*
	152	* Intercept and deal with "please trace me" request.
	153	*/
	154	if (uap->req == PT_TRACE_ME) {
	155	SET(p->p_flag, P_TRACED);
	156	/* Non-attached case, our tracer is our parent. */
	157	t->p_oppid = t->p_pptr->p_pid;
	158	return(0);
	159	}
9bccf70c A	160	if (uap->req == PT_SIGEXC) {
	161	if (ISSET(p->p_flag, P_TRACED)) {
	162	SET(p->p_flag, P_SIGEXC);
	163	return(0);
	164	} else
	165	return(EINVAL);
	166	}
1c79356b A	167
	168	/*
	169	* Locate victim, and make sure it is traceable.
	170	*/
	171	if ((t = pfind(uap->pid)) == NULL)
	172	return (ESRCH);
	173
e5568f75 A	174	AUDIT_ARG(process, t);
e5568f75 A	175
1c79356b A	176	/* We do not want ptrace to do anything with kernel, init
	177	* and mach_init
	178	*/
	179	if (uap->pid <=2 )
	180	return (EPERM);
	181
	182	task = t->task;
9bccf70c A	183	if (uap->req == PT_ATTACHEXC) {
	184	uap->req = PT_ATTACH;
	185	tr_sigexc = 1;
	186	}
1c79356b	187	if (uap->req == PT_ATTACH) {
91447636 A	188	int err;
	189
	190	if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE,
	191	t, (uintptr_t)&err, 0, 0) == 0 ) {
	192	/* it's OK to attach */
	193	SET(t->p_flag, P_TRACED);
	194	if (tr_sigexc)
	195	SET(t->p_flag, P_SIGEXC);
	196
	197	t->p_oppid = t->p_pptr->p_pid;
	198	if (t->p_pptr != p)
	199	proc_reparent(t, p);
	200
	201	if (get_task_userstop(task) == 0 ) {
	202	t->p_xstat = 0;
	203	psignal(t, SIGSTOP);
	204	} else {
	205	t->p_xstat = SIGSTOP;
	206	task_resume(task);
	207	}
	208	return(0);
0b4e3aa0	209	}
91447636 A	210	else {
	211	/* not allowed to attach, proper error code returned by kauth_authorize_process */
	212	if (ISSET(t->p_flag, P_NOATTACH)) {
	213	psignal(p, SIGSEGV);
	214	}
	215	return (err);
1c79356b	216	}
1c79356b A	217	}
	218
	219	/*
	220	* You can't do what you want to the process if:
	221	* (1) It's not being traced at all,
	222	*/
	223	if (!ISSET(t->p_flag, P_TRACED))
	224	return (EPERM);
	225
	226	/*
	227	* (2) it's not being traced by _you_, or
	228	*/
	229	if (t->p_pptr != p)
	230	return (EBUSY);
	231
	232	/*
	233	* (3) it's not currently stopped.
	234	*/
	235	if (t->p_stat != SSTOP)
	236	return (EBUSY);
	237
	238	/*
	239	* Mach version of ptrace executes request directly here,
	240	* thus simplifying the interaction of ptrace and signals.
	241	*/
	242	switch (uap->req) {
	243
	244	case PT_DETACH:
	245	if (t->p_oppid != t->p_pptr->p_pid) {
	246	struct proc *pp;
	247
	248	pp = pfind(t->p_oppid);
	249	proc_reparent(t, pp ? pp : initproc);
	250	}
	251
	252	t->p_oppid = 0;
	253	CLR(t->p_flag, P_TRACED);
9bccf70c	254	CLR(t->p_flag, P_SIGEXC);
1c79356b A	255	goto resume;
	256
	257	case PT_KILL:
	258	/*
	259	* Tell child process to kill itself after it
	260	* is resumed by adding NSIG to p_cursig. [see issig]
	261	*/
9bccf70c	262	psignal_lock(t, SIGKILL, 0);
1c79356b A	263	goto resume;
	264
	265	case PT_STEP: /* single step the child */
	266	case PT_CONTINUE: /* continue the child */
91447636 A	267	th_act = (thread_t)get_firstthread(task);
91447636 A	268	if (th_act == THREAD_NULL)
1c79356b A	269	goto errorLabel;
	270	ut = (uthread_t)get_bsdthread_info(th_act);
	271	locr0 = ut->uu_ar0;
	272	#if defined(i386)
	273	state_count = i386_NEW_THREAD_STATE_COUNT;
9bccf70c	274	if (thread_getstatus(th_act, i386_NEW_THREAD_STATE, &statep, &state_count) != KERN_SUCCESS) {
1c79356b A	275	goto errorLabel;
	276	}
	277	#elif defined(ppc)
55e303ae	278	state_count = PPC_THREAD_STATE64_COUNT;
91447636	279	if (thread_getstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, (mach_msg_type_number_t *)&state_count) != KERN_SUCCESS) {
1c79356b A	280	goto errorLabel;
	281	}
	282	#else
	283	#error architecture not supported
	284	#endif
91447636	285	if (uap->addr != (user_addr_t)1) {
1c79356b A	286	#if defined(i386)
	287	locr0[PC] = (int)uap->addr;
	288	#elif defined(ppc)
	289	#define ALIGNED(addr,size) (((unsigned)(addr)&((size)-1))==0)
	290	if (!ALIGNED((int)uap->addr, sizeof(int)))
	291	return (ERESTART);
	292
91447636	293	statep.srr0 = uap->addr;
55e303ae	294	state_count = PPC_THREAD_STATE64_COUNT;
91447636	295	if (thread_setstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, state_count) != KERN_SUCCESS) {
1c79356b A	296	goto errorLabel;
	297	}
	298	#undef ALIGNED
	299	#else
	300	#error architecture not implemented!
	301	#endif
91447636	302	} /* uap->addr != (user_addr_t)1 */
1c79356b	303
91447636	304	if ((unsigned)uap->data >= NSIG)
1c79356b A	305	goto errorLabel;
	306
	307	if (uap->data != 0) {
9bccf70c	308	psignal_lock(t, uap->data, 0);
1c79356b A	309	}
1c79356b A	310	#if defined(ppc)
55e303ae	311	state_count = PPC_THREAD_STATE64_COUNT;
91447636	312	if (thread_getstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, (mach_msg_type_number_t *)&state_count) != KERN_SUCCESS) {
1c79356b A	313	goto errorLabel;
	314	}
	315	#endif
	316
	317	#define MSR_SE_BIT 21
	318
	319	if (uap->req == PT_STEP) {
	320	#if defined(i386)
	321	locr0[PS] \|= PSL_T;
	322	#elif defined(ppc)
	323	statep.srr1 \|= MASK(MSR_SE);
	324	#else
	325	#error architecture not implemented!
	326	#endif
	327	} /* uap->req == PT_STEP */
	328	else { /* PT_CONTINUE - clear trace bit if set */
	329	#if defined(i386)
	330	locr0[PS] &= ~PSL_T;
	331	#elif defined(ppc)
	332	statep.srr1 &= ~MASK(MSR_SE);
	333	#endif
	334	}
	335	#if defined (ppc)
55e303ae	336	state_count = PPC_THREAD_STATE64_COUNT;
91447636	337	if (thread_setstatus(th_act, PPC_THREAD_STATE64, (thread_state_t)&statep, state_count) != KERN_SUCCESS) {
1c79356b A	338	goto errorLabel;
	339	}
	340	#endif
	341	resume:
	342	t->p_xstat = uap->data;
	343	t->p_stat = SRUN;
	344	if (t->sigwait) {
	345	wakeup((caddr_t)&(t->sigwait));
55e303ae A	346	if ((t->p_flag & P_SIGEXC) == 0)
55e303ae A	347	task_release(task);
1c79356b A	348	}
	349	break;
	350
9bccf70c	351	case PT_THUPDATE: {
9bccf70c A	352	if ((unsigned)uap->data >= NSIG)
9bccf70c A	353	goto errorLabel;
91447636 A	354	th_act = port_name_to_thread(CAST_DOWN(mach_port_name_t, uap->addr));
91447636 A	355	if (th_act == THREAD_NULL)
9bccf70c A	356	return (ESRCH);
	357	ut = (uthread_t)get_bsdthread_info(th_act);
	358	if (uap->data)
	359	ut->uu_siglist \|= sigmask(uap->data);
	360	t->p_xstat = uap->data;
	361	t->p_stat = SRUN;
91447636	362	thread_deallocate(th_act);
9bccf70c A	363	return(0);
	364	}
	365	break;
	366	errorLabel:
1c79356b	367	default:
1c79356b A	368	return(EINVAL);
1c79356b A	369	}
9bccf70c	370
1c79356b A	371	return(0);
	372	}
	373
91447636 A	374
	375	/*
	376	* determine if one process (cur_procp) can trace another process (traced_procp).
	377	*/
	378
	379	int
	380	cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
	381	{
	382	int my_err;
	383	/*
	384	* You can't trace a process if:
	385	* (1) it's the process that's doing the tracing,
	386	*/
	387	if (traced_procp->p_pid == cur_procp->p_pid) {
	388	*errp = EINVAL;
	389	return (0);
	390	}
	391
	392	/*
	393	* (2) it's already being traced, or
	394	*/
	395	if (ISSET(traced_procp->p_flag, P_TRACED)) {
	396	*errp = EBUSY;
	397	return (0);
	398	}
	399
	400	/*
	401	* (3) it's not owned by you, or is set-id on exec
	402	* (unless you're root).
	403	*/
	404	if ((creds->cr_ruid != proc_ucred(traced_procp)->cr_ruid \|\|
	405	ISSET(traced_procp->p_flag, P_SUGID)) &&
	406	(my_err = suser(creds, &cur_procp->p_acflag)) != 0) {
	407	*errp = my_err;
	408	return (0);
	409	}
	410
	411	if ((cur_procp->p_flag & P_TRACED) && isinferior(cur_procp, traced_procp)) {
	412	*errp = EPERM;
	413	return (0);
	414	}
	415
	416	if (ISSET(traced_procp->p_flag, P_NOATTACH)) {
	417	*errp = EBUSY;
	418	return (0);
	419	}
	420	return(1);
	421	}