[apple/xnu.git] / bsd / dev / dtrace / dtrace_subr.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * #pragma ident	"@(#)dtrace_subr.c	1.8	07/06/05 SMI"
 */

#include <stdarg.h>
#include <string.h>
#include <sys/malloc.h>
#include <sys/time.h>
#include <sys/dtrace.h>
#include <sys/dtrace_impl.h>
#include <sys/proc_internal.h>
#include <sys/vnode.h>
#include <kern/debug.h>
#include <kern/sched_prim.h>
#include <kern/task.h>

#if CONFIG_CSR
#include <sys/codesign.h>
#include <sys/csr.h>
#endif

/*
 * APPLE NOTE: Solaris proc_t is the struct.
 * Darwin's proc_t is a pointer to it.
 */
#define proc_t struct proc /* Steer clear of the Darwin typedef for proc_t */


/* Copied from an arch specific dtrace_subr.c. */
int (*dtrace_fasttrap_probe_ptr)(struct regs *);

/*
 * Following DTrace hooks are taken from Solaris' dtrace_subr.c
 * They're assigned in dtrace.c but Darwin never calls them.
 */
void (*dtrace_cpu_init)(processorid_t);
int (*dtrace_modload)(struct kmod_info *, uint32_t);
int (*dtrace_modunload)(struct kmod_info *);
void (*dtrace_helpers_cleanup)(proc_t *);
void (*dtrace_helpers_fork)(proc_t *, proc_t *);
void (*dtrace_cpustart_init)(void);
void (*dtrace_cpustart_fini)(void);

void (*dtrace_debugger_init)(void);
void (*dtrace_debugger_fini)(void);

dtrace_vtime_state_t dtrace_vtime_active = 0;
dtrace_cacheid_t dtrace_predcache_id = DTRACE_CACHEIDNONE + 1;

void (*dtrace_fasttrap_fork_ptr)(proc_t *, proc_t *);
void (*dtrace_fasttrap_exec_ptr)(proc_t *);
void (*dtrace_fasttrap_exit_ptr)(proc_t *);

/*
 * This function is called by cfork() in the event that it appears that
 * there may be dtrace tracepoints active in the parent process's address
 * space. This first confirms the existence of dtrace tracepoints in the
 * parent process and calls into the fasttrap module to remove the
 * corresponding tracepoints from the child. By knowing that there are
 * existing tracepoints, and ensuring they can't be removed, we can rely
 * on the fasttrap module remaining loaded.
 */
void
dtrace_fasttrap_fork(proc_t *p, proc_t *cp)
{
	if (dtrace_fasttrap_fork_ptr) {
		(*dtrace_fasttrap_fork_ptr)(p, cp);
	}
}


/*
 * DTrace wait for process execution
 *
 * This feature is using a list of entries, each entry containing a pointer
 * on a process description. The description is provided by a client, and it
 * contains the command we want to wait for along with a reserved space for
 * the caught process id.
 *
 * Once an awaited process has been spawned, it will be suspended before
 * notifying the client. Once the client has been back to userland, it's its
 * duty to resume the task.
 */

lck_mtx_t dtrace_procwaitfor_lock;

typedef struct dtrace_proc_awaited_entry {
	struct dtrace_procdesc			*pdesc;
	LIST_ENTRY(dtrace_proc_awaited_entry)	entries;
} dtrace_proc_awaited_entry_t;

LIST_HEAD(listhead, dtrace_proc_awaited_entry) dtrace_proc_awaited_head
	= LIST_HEAD_INITIALIZER(dtrace_proc_awaited_head);

void (*dtrace_proc_waitfor_exec_ptr)(proc_t*) = NULL;

static int
dtrace_proc_get_execpath(proc_t *p, char *buffer, int *maxlen)
{
	int err = 0, vid = 0;
	vnode_t tvp = NULLVP, nvp = NULLVP;

	ASSERT(p);
	ASSERT(buffer);
	ASSERT(maxlen);

	if ((tvp = p->p_textvp) == NULLVP)
		return ESRCH;

	vid = vnode_vid(tvp);
	if ((err = vnode_getwithvid(tvp, vid)) != 0)
		return err;

	if ((err = vn_getpath_fsenter(tvp, buffer, maxlen)) != 0)
		return err;
	vnode_put(tvp);

	if ((err = vnode_lookup(buffer, 0, &nvp, vfs_context_current())) != 0)
		return err;
	if (nvp != NULLVP)
		vnode_put(nvp);

	return 0;
}


static void
dtrace_proc_exec_notification(proc_t *p) {
	dtrace_proc_awaited_entry_t *entry, *tmp;
	static char execpath[MAXPATHLEN];

	ASSERT(p);
	ASSERT(p->p_pid != -1);
	ASSERT(current_task() != p->task);

	lck_mtx_lock(&dtrace_procwaitfor_lock);

	LIST_FOREACH_SAFE(entry, &dtrace_proc_awaited_head, entries, tmp) {
		/* By default consider we're using p_comm. */
		char *pname = p->p_comm;

		/* Already matched with another process. */
		if ((entry->pdesc->p_pid != -1))
			continue;

		/* p_comm is too short, use the execpath. */
		if (entry->pdesc->p_name_length >= MAXCOMLEN) {
			/*
			 * Retrieve the executable path. After the call, length contains
			 * the length of the string + 1.
			 */
			int length = sizeof(execpath);
			if (dtrace_proc_get_execpath(p, execpath, &length) != 0)
				continue;
			/* Move the cursor to the position after the last / */
			pname = &execpath[length - 1];
			while (pname != execpath && *pname != '/')
				pname--;
			pname = (*pname == '/') ? pname + 1 : pname;
		}

		if (!strcmp(entry->pdesc->p_name, pname)) {
			entry->pdesc->p_pid = p->p_pid;
			task_pidsuspend(p->task);
			wakeup(entry);
		}
	}

	lck_mtx_unlock(&dtrace_procwaitfor_lock);
}

int
dtrace_proc_waitfor(dtrace_procdesc_t* pdesc) {
	dtrace_proc_awaited_entry_t entry;
	int res;

	ASSERT(pdesc);
	ASSERT(pdesc->p_name);

	/*
	 * Never trust user input, compute the length of the process name and ensure the
	 * string is null terminated.
	 */
	pdesc->p_name_length = strnlen(pdesc->p_name, sizeof(pdesc->p_name));
	if (pdesc->p_name_length >= (int) sizeof(pdesc->p_name))
		return -1;

	lck_mtx_lock(&dtrace_procwaitfor_lock);

	/* Initialize and insert the entry, then install the hook. */
	pdesc->p_pid = -1;
	entry.pdesc = pdesc;
	LIST_INSERT_HEAD(&dtrace_proc_awaited_head, &entry, entries);
	dtrace_proc_waitfor_exec_ptr = &dtrace_proc_exec_notification;

	/* Sleep until the process has been executed */
	res = msleep(&entry, &dtrace_procwaitfor_lock, PCATCH, "dtrace_proc_waitfor", NULL);

	/* Remove the entry and the hook if it is not needed anymore. */
	LIST_REMOVE(&entry, entries);
	if (LIST_EMPTY(&dtrace_proc_awaited_head))
		dtrace_proc_waitfor_exec_ptr = NULL;

	lck_mtx_unlock(&dtrace_procwaitfor_lock);

	return res;
}


typedef struct dtrace_invop_hdlr {
	int (*dtih_func)(uintptr_t, uintptr_t *, uintptr_t);
	struct dtrace_invop_hdlr *dtih_next;
} dtrace_invop_hdlr_t;

dtrace_invop_hdlr_t *dtrace_invop_hdlr;

int
dtrace_invop(uintptr_t, uintptr_t *, uintptr_t);

int
dtrace_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
{
	dtrace_invop_hdlr_t *hdlr;
	int rval;

	for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next) {
		if ((rval = hdlr->dtih_func(addr, stack, eax)) != 0)
			return (rval);
	}

	return (0);
}

void
dtrace_invop_add(int (*func)(uintptr_t, uintptr_t *, uintptr_t))
{
	dtrace_invop_hdlr_t *hdlr;

	hdlr = kmem_alloc(sizeof (dtrace_invop_hdlr_t), KM_SLEEP);
	hdlr->dtih_func = func;
	hdlr->dtih_next = dtrace_invop_hdlr;
	dtrace_invop_hdlr = hdlr;
}

void
dtrace_invop_remove(int (*func)(uintptr_t, uintptr_t *, uintptr_t))
{
	dtrace_invop_hdlr_t *hdlr = dtrace_invop_hdlr, *prev = NULL;

	for (;;) {
		if (hdlr == NULL)
			panic("attempt to remove non-existent invop handler");

		if (hdlr->dtih_func == func)
			break;

		prev = hdlr;
		hdlr = hdlr->dtih_next;
	}

	if (prev == NULL) {
		ASSERT(dtrace_invop_hdlr == hdlr);
		dtrace_invop_hdlr = hdlr->dtih_next;
	} else {
		ASSERT(dtrace_invop_hdlr != hdlr);
		prev->dtih_next = hdlr->dtih_next;
	}

	kmem_free(hdlr, sizeof (dtrace_invop_hdlr_t));
}

static minor_t next_minor = 0;
static dtrace_state_t* dtrace_clients[DTRACE_NCLIENTS] = {NULL};


minor_t
dtrace_state_reserve(void)
{
	for (int i = 0; i < DTRACE_NCLIENTS; i++) {
		minor_t minor = atomic_add_32(&next_minor, 1) % DTRACE_NCLIENTS;
		if (dtrace_clients[minor] == NULL)
			return minor;
	}
	return 0;
}

dtrace_state_t*
dtrace_state_get(minor_t minor)
{
	ASSERT(minor < DTRACE_NCLIENTS);
	return dtrace_clients[minor];
}

dtrace_state_t*
dtrace_state_allocate(minor_t minor)
{
	dtrace_state_t *state = _MALLOC(sizeof(dtrace_state_t), M_TEMP, M_ZERO | M_WAITOK);
	if (dtrace_casptr(&dtrace_clients[minor], NULL, state) != NULL) {
		// We have been raced by another client for this number, abort
		_FREE(state, M_TEMP);
		return NULL;
	}
	return state;
}

void
dtrace_state_free(minor_t minor)
{
	dtrace_state_t *state = dtrace_clients[minor];
	dtrace_clients[minor] = NULL;
	_FREE(state, M_TEMP);
}


void
dtrace_restriction_policy_load(void)
{
}

/*
 * Check if DTrace has been restricted by the current security policy.
 */
boolean_t
dtrace_is_restricted(void)
{
#if CONFIG_CSR
	if (csr_check(CSR_ALLOW_UNRESTRICTED_DTRACE) != 0)
		return TRUE;
#endif

	return FALSE;
}

boolean_t
dtrace_are_restrictions_relaxed(void)
{
#if CONFIG_CSR
	if (csr_check(CSR_ALLOW_APPLE_INTERNAL) == 0)
		return TRUE;
#endif

	return FALSE;
}

boolean_t
dtrace_fbt_probes_restricted(void)
{

#if CONFIG_CSR
	if (dtrace_is_restricted() && !dtrace_are_restrictions_relaxed())
		return TRUE;
#endif

	return FALSE;
}

boolean_t
dtrace_sdt_probes_restricted(void)
{

	return FALSE;
}

/*
 * Check if the process can be attached.
 */
boolean_t
dtrace_can_attach_to_proc(proc_t *proc)
{
#pragma unused(proc)
	ASSERT(proc != NULL);

#if CONFIG_CSR
	if (cs_restricted(proc))
		return FALSE;
#endif

	return TRUE;
}
Commit	Line	Data
2d21ac55 A	1	/*
	2	* CDDL HEADER START
	3	*
	4	* The contents of this file are subject to the terms of the
	5	* Common Development and Distribution License (the "License").
	6	* You may not use this file except in compliance with the License.
	7	*
	8	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	9	* or http://www.opensolaris.org/os/licensing.
	10	* See the License for the specific language governing permissions
	11	* and limitations under the License.
	12	*
	13	* When distributing Covered Code, include this CDDL HEADER in each
	14	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	15	* If applicable, add the following below this CDDL HEADER, with the
	16	* fields enclosed by brackets "[]" replaced with your own identifying
	17	* information: Portions Copyright [yyyy] [name of copyright owner]
	18	*
	19	* CDDL HEADER END
	20	*/
	21
	22	/*
b0d623f7	23	* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
2d21ac55 A	24	* Use is subject to license terms.
	25	*/
	26
	27	/*
b0d623f7	28	* #pragma ident "@(#)dtrace_subr.c 1.8 07/06/05 SMI"
2d21ac55 A	29	*/
	30
	31	#include <stdarg.h>
	32	#include <string.h>
	33	#include <sys/malloc.h>
	34	#include <sys/time.h>
	35	#include <sys/dtrace.h>
	36	#include <sys/dtrace_impl.h>
fe8ab488	37	#include <sys/proc_internal.h>
3e170ce0	38	#include <sys/vnode.h>
2d21ac55	39	#include <kern/debug.h>
fe8ab488 A	40	#include <kern/sched_prim.h>
fe8ab488 A	41	#include <kern/task.h>
2d21ac55	42
fe8ab488 A	43	#if CONFIG_CSR
	44	#include <sys/codesign.h>
	45	#include <sys/csr.h>
2d21ac55 A	46	#endif
2d21ac55 A	47
fe8ab488 A	48	/*
	49	* APPLE NOTE: Solaris proc_t is the struct.
	50	* Darwin's proc_t is a pointer to it.
	51	*/
	52	#define proc_t struct proc /* Steer clear of the Darwin typedef for proc_t */
	53
	54
2d21ac55 A	55	/* Copied from an arch specific dtrace_subr.c. */
	56	int (dtrace_fasttrap_probe_ptr)(struct regs );
	57
	58	/*
	59	* Following DTrace hooks are taken from Solaris' dtrace_subr.c
	60	* They're assigned in dtrace.c but Darwin never calls them.
	61	*/
	62	void (*dtrace_cpu_init)(processorid_t);
316670eb	63	int (dtrace_modload)(struct kmod_info , uint32_t);
6d2010ae	64	int (dtrace_modunload)(struct kmod_info );
2d21ac55	65	void (dtrace_helpers_cleanup)(proc_t );
2d21ac55 A	66	void (dtrace_helpers_fork)(proc_t , proc_t *);
	67	void (*dtrace_cpustart_init)(void);
	68	void (*dtrace_cpustart_fini)(void);
	69
2d21ac55 A	70	void (*dtrace_debugger_init)(void);
	71	void (*dtrace_debugger_fini)(void);
	72
	73	dtrace_vtime_state_t dtrace_vtime_active = 0;
	74	dtrace_cacheid_t dtrace_predcache_id = DTRACE_CACHEIDNONE + 1;
	75
	76	void (dtrace_fasttrap_fork_ptr)(proc_t , proc_t *);
	77	void (dtrace_fasttrap_exec_ptr)(proc_t );
	78	void (dtrace_fasttrap_exit_ptr)(proc_t );
	79
	80	/*
	81	* This function is called by cfork() in the event that it appears that
	82	* there may be dtrace tracepoints active in the parent process's address
	83	* space. This first confirms the existence of dtrace tracepoints in the
	84	* parent process and calls into the fasttrap module to remove the
	85	* corresponding tracepoints from the child. By knowing that there are
	86	* existing tracepoints, and ensuring they can't be removed, we can rely
	87	* on the fasttrap module remaining loaded.
	88	*/
	89	void
	90	dtrace_fasttrap_fork(proc_t p, proc_t cp)
	91	{
2d21ac55 A	92	if (dtrace_fasttrap_fork_ptr) {
	93	(*dtrace_fasttrap_fork_ptr)(p, cp);
	94	}
	95	}
	96
fe8ab488 A	97
	98	/*
	99	* DTrace wait for process execution
	100	*
	101	* This feature is using a list of entries, each entry containing a pointer
	102	* on a process description. The description is provided by a client, and it
	103	* contains the command we want to wait for along with a reserved space for
	104	* the caught process id.
	105	*
	106	* Once an awaited process has been spawned, it will be suspended before
	107	* notifying the client. Once the client has been back to userland, it's its
	108	* duty to resume the task.
	109	*/
	110
	111	lck_mtx_t dtrace_procwaitfor_lock;
	112
	113	typedef struct dtrace_proc_awaited_entry {
	114	struct dtrace_procdesc *pdesc;
	115	LIST_ENTRY(dtrace_proc_awaited_entry) entries;
	116	} dtrace_proc_awaited_entry_t;
	117
	118	LIST_HEAD(listhead, dtrace_proc_awaited_entry) dtrace_proc_awaited_head
	119	= LIST_HEAD_INITIALIZER(dtrace_proc_awaited_head);
	120
	121	void (dtrace_proc_waitfor_exec_ptr)(proc_t) = NULL;
	122
3e170ce0 A	123	static int
	124	dtrace_proc_get_execpath(proc_t p, char buffer, int *maxlen)
	125	{
	126	int err = 0, vid = 0;
	127	vnode_t tvp = NULLVP, nvp = NULLVP;
	128
	129	ASSERT(p);
	130	ASSERT(buffer);
	131	ASSERT(maxlen);
	132
	133	if ((tvp = p->p_textvp) == NULLVP)
	134	return ESRCH;
	135
	136	vid = vnode_vid(tvp);
	137	if ((err = vnode_getwithvid(tvp, vid)) != 0)
	138	return err;
	139
	140	if ((err = vn_getpath_fsenter(tvp, buffer, maxlen)) != 0)
	141	return err;
	142	vnode_put(tvp);
	143
	144	if ((err = vnode_lookup(buffer, 0, &nvp, vfs_context_current())) != 0)
	145	return err;
	146	if (nvp != NULLVP)
	147	vnode_put(nvp);
	148
	149	return 0;
	150	}
	151
	152
fe8ab488 A	153	static void
	154	dtrace_proc_exec_notification(proc_t *p) {
	155	dtrace_proc_awaited_entry_t entry, tmp;
3e170ce0	156	static char execpath[MAXPATHLEN];
fe8ab488 A	157
	158	ASSERT(p);
	159	ASSERT(p->p_pid != -1);
	160	ASSERT(current_task() != p->task);
	161
	162	lck_mtx_lock(&dtrace_procwaitfor_lock);
	163
fe8ab488	164	LIST_FOREACH_SAFE(entry, &dtrace_proc_awaited_head, entries, tmp) {
3e170ce0 A	165	/* By default consider we're using p_comm. */
	166	char *pname = p->p_comm;
	167
	168	/* Already matched with another process. */
	169	if ((entry->pdesc->p_pid != -1))
	170	continue;
	171
	172	/* p_comm is too short, use the execpath. */
	173	if (entry->pdesc->p_name_length >= MAXCOMLEN) {
	174	/*
	175	* Retrieve the executable path. After the call, length contains
	176	* the length of the string + 1.
	177	*/
	178	int length = sizeof(execpath);
	179	if (dtrace_proc_get_execpath(p, execpath, &length) != 0)
	180	continue;
	181	/* Move the cursor to the position after the last / */
	182	pname = &execpath[length - 1];
	183	while (pname != execpath && *pname != '/')
	184	pname--;
	185	pname = (*pname == '/') ? pname + 1 : pname;
	186	}
	187
	188	if (!strcmp(entry->pdesc->p_name, pname)) {
fe8ab488 A	189	entry->pdesc->p_pid = p->p_pid;
	190	task_pidsuspend(p->task);
	191	wakeup(entry);
	192	}
	193	}
	194
	195	lck_mtx_unlock(&dtrace_procwaitfor_lock);
	196	}
	197
	198	int
	199	dtrace_proc_waitfor(dtrace_procdesc_t* pdesc) {
	200	dtrace_proc_awaited_entry_t entry;
	201	int res;
	202
	203	ASSERT(pdesc);
3e170ce0 A	204	ASSERT(pdesc->p_name);
	205
	206	/*
	207	* Never trust user input, compute the length of the process name and ensure the
	208	* string is null terminated.
	209	*/
	210	pdesc->p_name_length = strnlen(pdesc->p_name, sizeof(pdesc->p_name));
	211	if (pdesc->p_name_length >= (int) sizeof(pdesc->p_name))
	212	return -1;
fe8ab488 A	213
	214	lck_mtx_lock(&dtrace_procwaitfor_lock);
	215
	216	/* Initialize and insert the entry, then install the hook. */
	217	pdesc->p_pid = -1;
	218	entry.pdesc = pdesc;
	219	LIST_INSERT_HEAD(&dtrace_proc_awaited_head, &entry, entries);
	220	dtrace_proc_waitfor_exec_ptr = &dtrace_proc_exec_notification;
	221
	222	/* Sleep until the process has been executed */
	223	res = msleep(&entry, &dtrace_procwaitfor_lock, PCATCH, "dtrace_proc_waitfor", NULL);
	224
	225	/* Remove the entry and the hook if it is not needed anymore. */
	226	LIST_REMOVE(&entry, entries);
	227	if (LIST_EMPTY(&dtrace_proc_awaited_head))
	228	dtrace_proc_waitfor_exec_ptr = NULL;
	229
	230	lck_mtx_unlock(&dtrace_procwaitfor_lock);
	231
	232	return res;
	233	}
	234
	235
2d21ac55 A	236	typedef struct dtrace_invop_hdlr {
	237	int (dtih_func)(uintptr_t, uintptr_t , uintptr_t);
	238	struct dtrace_invop_hdlr *dtih_next;
	239	} dtrace_invop_hdlr_t;
	240
	241	dtrace_invop_hdlr_t *dtrace_invop_hdlr;
	242
	243	int
	244	dtrace_invop(uintptr_t, uintptr_t *, uintptr_t);
	245
	246	int
	247	dtrace_invop(uintptr_t addr, uintptr_t *stack, uintptr_t eax)
	248	{
	249	dtrace_invop_hdlr_t *hdlr;
	250	int rval;
	251
	252	for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next) {
	253	if ((rval = hdlr->dtih_func(addr, stack, eax)) != 0)
	254	return (rval);
	255	}
	256
	257	return (0);
	258	}
	259
	260	void
	261	dtrace_invop_add(int (func)(uintptr_t, uintptr_t , uintptr_t))
	262	{
	263	dtrace_invop_hdlr_t *hdlr;
	264
	265	hdlr = kmem_alloc(sizeof (dtrace_invop_hdlr_t), KM_SLEEP);
	266	hdlr->dtih_func = func;
	267	hdlr->dtih_next = dtrace_invop_hdlr;
	268	dtrace_invop_hdlr = hdlr;
	269	}
	270
	271	void
	272	dtrace_invop_remove(int (func)(uintptr_t, uintptr_t , uintptr_t))
	273	{
	274	dtrace_invop_hdlr_t hdlr = dtrace_invop_hdlr, prev = NULL;
	275
	276	for (;;) {
	277	if (hdlr == NULL)
	278	panic("attempt to remove non-existent invop handler");
	279
	280	if (hdlr->dtih_func == func)
	281	break;
	282
	283	prev = hdlr;
	284	hdlr = hdlr->dtih_next;
	285	}
	286
	287	if (prev == NULL) {
	288	ASSERT(dtrace_invop_hdlr == hdlr);
	289	dtrace_invop_hdlr = hdlr->dtih_next;
	290	} else {
	291	ASSERT(dtrace_invop_hdlr != hdlr);
	292	prev->dtih_next = hdlr->dtih_next;
	293	}
	294
	295	kmem_free(hdlr, sizeof (dtrace_invop_hdlr_t));
	296	}
	297
39037602 A	298	static minor_t next_minor = 0;
	299	static dtrace_state_t* dtrace_clients[DTRACE_NCLIENTS] = {NULL};
	300
	301
	302	minor_t
	303	dtrace_state_reserve(void)
	304	{
	305	for (int i = 0; i < DTRACE_NCLIENTS; i++) {
	306	minor_t minor = atomic_add_32(&next_minor, 1) % DTRACE_NCLIENTS;
	307	if (dtrace_clients[minor] == NULL)
	308	return minor;
	309	}
	310	return 0;
	311	}
	312
	313	dtrace_state_t*
	314	dtrace_state_get(minor_t minor)
	315	{
	316	ASSERT(minor < DTRACE_NCLIENTS);
	317	return dtrace_clients[minor];
	318	}
	319
	320	dtrace_state_t*
	321	dtrace_state_allocate(minor_t minor)
	322	{
	323	dtrace_state_t *state = _MALLOC(sizeof(dtrace_state_t), M_TEMP, M_ZERO \| M_WAITOK);
	324	if (dtrace_casptr(&dtrace_clients[minor], NULL, state) != NULL) {
	325	// We have been raced by another client for this number, abort
	326	_FREE(state, M_TEMP);
	327	return NULL;
	328	}
	329	return state;
	330	}
	331
	332	void
	333	dtrace_state_free(minor_t minor)
	334	{
	335	dtrace_state_t *state = dtrace_clients[minor];
	336	dtrace_clients[minor] = NULL;
	337	_FREE(state, M_TEMP);
	338	}
3e170ce0 A	339
	340
	341
	342	void
	343	dtrace_restriction_policy_load(void)
	344	{
	345	}
	346
fe8ab488 A	347	/*
	348	* Check if DTrace has been restricted by the current security policy.
	349	*/
	350	boolean_t
	351	dtrace_is_restricted(void)
	352	{
	353	#if CONFIG_CSR
	354	if (csr_check(CSR_ALLOW_UNRESTRICTED_DTRACE) != 0)
	355	return TRUE;
	356	#endif
	357
	358	return FALSE;
	359	}
	360
3e170ce0	361	boolean_t
39037602	362	dtrace_are_restrictions_relaxed(void)
3e170ce0 A	363	{
	364	#if CONFIG_CSR
	365	if (csr_check(CSR_ALLOW_APPLE_INTERNAL) == 0)
	366	return TRUE;
	367	#endif
	368
	369	return FALSE;
	370	}
	371
	372	boolean_t
	373	dtrace_fbt_probes_restricted(void)
	374	{
	375
	376	#if CONFIG_CSR
39037602	377	if (dtrace_is_restricted() && !dtrace_are_restrictions_relaxed())
3e170ce0 A	378	return TRUE;
	379	#endif
	380
	381	return FALSE;
	382	}
	383
39037602 A	384	boolean_t
	385	dtrace_sdt_probes_restricted(void)
	386	{
	387
	388	return FALSE;
	389	}
	390
fe8ab488 A	391	/*
	392	* Check if the process can be attached.
	393	*/
	394	boolean_t
	395	dtrace_can_attach_to_proc(proc_t *proc)
	396	{
	397	#pragma unused(proc)
	398	ASSERT(proc != NULL);
	399
	400	#if CONFIG_CSR
3e170ce0	401	if (cs_restricted(proc))
fe8ab488 A	402	return FALSE;
	403	#endif
	404
	405	return TRUE;
	406	}
	407