xref: /titanic_52/usr/src/uts/common/syscall/tasksys.c (revision 18c2aff776a775d34a4c9893a4c72e0434d68e36)
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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * System calls for creating and inquiring about tasks and projects
30  */
31 
32 #include <sys/param.h>
33 #include <sys/types.h>
34 #include <sys/errno.h>
35 #include <sys/thread.h>
36 #include <sys/proc.h>
37 #include <sys/task.h>
38 #include <sys/systm.h>
39 #include <sys/project.h>
40 #include <sys/cpuvar.h>
41 #include <sys/policy.h>
42 #include <sys/zone.h>
43 #include <sys/rctl.h>
44 
45 /*
46  * Limit projlist to 256k projects.
47  */
48 #define	MAX_PROJLIST_BUFSIZE		1048576
49 
50 typedef struct projlist_walk {
51 	projid_t	*pw_buf;
52 	size_t		pw_bufsz;
53 } projlist_walk_t;
54 
55 /*
56  * taskid_t tasksys_settaskid(projid_t projid, uint_t flags);
57  *
58  * Overview
59  *   Place the calling process in a new task if sufficiently privileged.  If the
60  *   present task is finalized, the process may not create a new task.
61  *
62  * Return values
63  *   0 on success, errno on failure.
64  */
65 static long
66 tasksys_settaskid(projid_t projid, uint_t flags)
67 {
68 	proc_t *p = ttoproc(curthread);
69 	kproject_t *oldpj;
70 	kproject_t *kpj;
71 	task_t *tk, *oldtk;
72 	rctl_entity_p_t e;
73 	zone_t *zone;
74 	int rctlfail = 0;
75 
76 	if (secpolicy_tasksys(CRED()) != 0)
77 		return (set_errno(EPERM));
78 
79 	if (projid < 0 || projid > MAXPROJID)
80 		return (set_errno(EINVAL));
81 
82 	if (flags & ~TASK_FINAL)
83 		return (set_errno(EINVAL));
84 
85 	mutex_enter(&pidlock);
86 	if (p->p_task->tk_flags & TASK_FINAL) {
87 		mutex_exit(&pidlock);
88 		return (set_errno(EACCES));
89 	}
90 	mutex_exit(&pidlock);
91 
92 	/*
93 	 * Try to stop all other lwps in the process while we're changing
94 	 * our project.  This way, curthread doesn't need to grab its own
95 	 * thread_lock to find its project ID (see curprojid()).  If this
96 	 * is the /proc agent lwp, we know that the other lwps are already
97 	 * held.  If we failed to hold all lwps, bail out and return EINTR.
98 	 */
99 	if (curthread != p->p_agenttp && !holdlwps(SHOLDFORK1))
100 		return (set_errno(EINTR));
101 	/*
102 	 * Put a hold on our new project and make sure that nobody is
103 	 * trying to bind it to a pool while we're joining.
104 	 */
105 	kpj = project_hold_by_id(projid, getzoneid(), PROJECT_HOLD_INSERT);
106 	e.rcep_p.proj = kpj;
107 	e.rcep_t = RCENTITY_PROJECT;
108 
109 	mutex_enter(&p->p_lock);
110 	oldpj = p->p_task->tk_proj;
111 	zone = p->p_zone;
112 
113 	mutex_enter(&zone->zone_nlwps_lock);
114 	mutex_enter(&zone->zone_rctl_lock);
115 
116 	if (kpj->kpj_nlwps + p->p_lwpcnt > kpj->kpj_nlwps_ctl)
117 		if (rctl_test_entity(rc_project_nlwps, kpj->kpj_rctls, p, &e,
118 		    p->p_lwpcnt, 0) & RCT_DENY)
119 			rctlfail = 1;
120 
121 	if (kpj->kpj_ntasks + 1 > kpj->kpj_ntasks_ctl)
122 		if (rctl_test_entity(rc_project_ntasks, kpj->kpj_rctls, p, &e,
123 		    1, 0) & RCT_DENY)
124 			rctlfail = 1;
125 
126 	if (kpj->kpj_data.kpd_locked_mem + p->p_locked_mem
127 	    > kpj->kpj_data.kpd_locked_mem_ctl)
128 		if (rctl_test_entity(rc_project_locked_mem, kpj->kpj_rctls, p,
129 		    &e, p->p_locked_mem, 0) &RCT_DENY)
130 			rctlfail = 1;
131 
132 	if (rctlfail) {
133 		mutex_exit(&zone->zone_rctl_lock);
134 		mutex_exit(&zone->zone_nlwps_lock);
135 		if (curthread != p->p_agenttp)
136 			continuelwps(p);
137 		mutex_exit(&p->p_lock);
138 		return (set_errno(EAGAIN));
139 	}
140 	kpj->kpj_data.kpd_locked_mem += p->p_locked_mem;
141 	kpj->kpj_nlwps += p->p_lwpcnt;
142 	kpj->kpj_ntasks++;
143 
144 	oldpj->kpj_data.kpd_locked_mem -= p->p_locked_mem;
145 	oldpj->kpj_nlwps -= p->p_lwpcnt;
146 
147 	mutex_exit(&zone->zone_rctl_lock);
148 	mutex_exit(&zone->zone_nlwps_lock);
149 	mutex_exit(&p->p_lock);
150 
151 	mutex_enter(&kpj->kpj_poolbind);
152 	tk = task_create(projid, curproc->p_zone);
153 	mutex_enter(&cpu_lock);
154 	/*
155 	 * Returns with p_lock held.
156 	 */
157 	oldtk = task_join(tk, flags);
158 	if (curthread != p->p_agenttp)
159 		continuelwps(p);
160 	mutex_exit(&p->p_lock);
161 	mutex_exit(&cpu_lock);
162 	mutex_exit(&kpj->kpj_poolbind);
163 	task_rele(oldtk);
164 	project_rele(kpj);
165 	return (tk->tk_tkid);
166 }
167 
168 /*
169  * taskid_t tasksys_gettaskid(void);
170  *
171  * Overview
172  *   Return the current task ID for this process.
173  *
174  * Return value
175  *   The ID for the task to which the current process belongs.
176  */
177 static long
178 tasksys_gettaskid()
179 {
180 	long ret;
181 	proc_t *p = ttoproc(curthread);
182 
183 	mutex_enter(&pidlock);
184 	ret = p->p_task->tk_tkid;
185 	mutex_exit(&pidlock);
186 	return (ret);
187 }
188 
189 /*
190  * projid_t tasksys_getprojid(void);
191  *
192  * Overview
193  *   Return the current project ID for this process.
194  *
195  * Return value
196  *   The ID for the project to which the current process belongs.
197  */
198 static long
199 tasksys_getprojid()
200 {
201 	long ret;
202 	proc_t *p = ttoproc(curthread);
203 
204 	mutex_enter(&pidlock);
205 	ret = p->p_task->tk_proj->kpj_id;
206 	mutex_exit(&pidlock);
207 	return (ret);
208 }
209 
210 static int
211 tasksys_projlist_cb(kproject_t *kp, void *buf)
212 {
213 	projlist_walk_t *pw = (projlist_walk_t *)buf;
214 
215 	if (pw && pw->pw_bufsz >= sizeof (projid_t)) {
216 		*pw->pw_buf = kp->kpj_id;
217 		pw->pw_buf++;
218 		pw->pw_bufsz -= sizeof (projid_t);
219 	}
220 
221 	return (0);
222 }
223 
224 /*
225  * long tasksys_projlist(void *buf, size_t bufsz)
226  *
227  * Overview
228  *   Return a buffer containing the project IDs of all currently active projects
229  *   in the current zone.
230  *
231  * Return values
232  *   The minimum size of a buffer sufficiently large to contain all of the
233  *   active project IDs, or -1 if an error occurs during copyout.
234  */
235 static long
236 tasksys_projlist(void *buf, size_t bufsz)
237 {
238 	long ret = 0;
239 	projlist_walk_t pw;
240 	void *kbuf;
241 
242 	if (buf == NULL || bufsz == 0)
243 		return (project_walk_all(getzoneid(), tasksys_projlist_cb,
244 		    NULL));
245 
246 	if (bufsz > MAX_PROJLIST_BUFSIZE)
247 		return (set_errno(ENOMEM));
248 
249 	kbuf = pw.pw_buf = kmem_zalloc(bufsz, KM_SLEEP);
250 	pw.pw_bufsz = bufsz;
251 
252 	ret = project_walk_all(getzoneid(), tasksys_projlist_cb, &pw);
253 
254 	if (copyout(kbuf, buf, bufsz) == -1)
255 		ret = set_errno(EFAULT);
256 
257 	kmem_free(kbuf, bufsz);
258 	return (ret);
259 }
260 
261 long
262 tasksys(int code, projid_t projid, uint_t flags, void *projidbuf, size_t pbufsz)
263 {
264 	switch (code) {
265 	case 0:
266 		return (tasksys_settaskid(projid, flags));
267 	case 1:
268 		return (tasksys_gettaskid());
269 	case 2:
270 		return (tasksys_getprojid());
271 	case 3:
272 		return (tasksys_projlist(projidbuf, pbufsz));
273 	default:
274 		return (set_errno(EINVAL));
275 	}
276 }
277