p1003_1b.c revision 75893 
1/*
2 * Copyright (c) 1996, 1997, 1998
3 *	HD Associates, Inc.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by HD Associates, Inc
16 * 4. Neither the name of the author nor the names of any co-contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: head/sys/kern/p1003_1b.c 75893 2001-04-24 00:51:53Z jhb $
33 */
34
35/* p1003_1b: Real Time common code.
36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/kernel.h>
41#include <sys/sysent.h>
42#include <sys/proc.h>
43#include <sys/syslog.h>
44#include <sys/module.h>
45#include <sys/sysproto.h>
46#include <sys/sysctl.h>
47
48#include <posix4/posix4.h>
49
50MALLOC_DEFINE(M_P31B, "p1003.1b", "Posix 1003.1B");
51
52/* p31b_proc: Return a proc struct corresponding to a pid to operate on.
53 *
54 * Enforce permission policy.
55 *
56 * The policy is the same as for sending signals except there
57 * is no notion of process groups.
58 *
59 * pid == 0 means my process.
60 *
61 * This is disabled until I've got a permission gate in again:
62 * only root can do this.
63 */
64
65#if 0
66/*
67 * This is stolen from CANSIGNAL in kern_sig:
68 *
69 * Can process p, with pcred pc, do "write flavor" operations to process q?
70 */
71#define CAN_AFFECT(p, pc, q) \
72	((pc)->pc_ucred->cr_uid == 0 || \
73	    (pc)->p_ruid == (q)->p_cred->p_ruid || \
74	    (pc)->pc_ucred->cr_uid == (q)->p_cred->p_ruid || \
75	    (pc)->p_ruid == (q)->p_ucred->cr_uid || \
76	    (pc)->pc_ucred->cr_uid == (q)->p_ucred->cr_uid)
77#else
78#define CAN_AFFECT(p, pc, q) ((pc)->pc_ucred->cr_uid == 0)
79#endif
80
81/*
82 * p31b_proc: Look up a proc from a PID.  If proc is 0 it is
83 * my own proc.
84 */
85int p31b_proc(struct proc *p, pid_t pid, struct proc **pp)
86{
87	int ret = 0;
88	struct proc *other_proc = 0;
89
90	if (pid == 0) {
91		other_proc = p;
92		PROC_LOCK(p);
93	} else
94		other_proc = pfind(pid);
95
96	if (other_proc)
97	{
98		/* Enforce permission policy.
99		 */
100		if (CAN_AFFECT(p, p->p_cred, other_proc))
101			*pp = other_proc;
102		else
103			ret = EPERM;
104		PROC_UNLOCK(other_proc);
105	}
106	else
107		ret = ESRCH;
108
109	return ret;
110}
111
112/* The system calls return ENOSYS if an entry is called that is
113 * not run-time supported.  I am also logging since some programs
114 * start to use this when they shouldn't.  That will be removed if annoying.
115 */
116int
117syscall_not_present(struct proc *p, const char *s, struct nosys_args *uap)
118{
119	log(LOG_ERR, "cmd %s pid %d tried to use non-present %s\n",
120			p->p_comm, p->p_pid, s);
121
122	/* a " return nosys(p, uap); " here causes a core dump.
123	 */
124
125	return ENOSYS;
126}
127
128#if !defined(_KPOSIX_PRIORITY_SCHEDULING)
129
130/* Not configured but loadable via a module:
131 */
132
133static int sched_attach(void)
134{
135	return 0;
136}
137
138SYSCALL_NOT_PRESENT_GEN(sched_setparam)
139SYSCALL_NOT_PRESENT_GEN(sched_getparam)
140SYSCALL_NOT_PRESENT_GEN(sched_setscheduler)
141SYSCALL_NOT_PRESENT_GEN(sched_getscheduler)
142SYSCALL_NOT_PRESENT_GEN(sched_yield)
143SYSCALL_NOT_PRESENT_GEN(sched_get_priority_max)
144SYSCALL_NOT_PRESENT_GEN(sched_get_priority_min)
145SYSCALL_NOT_PRESENT_GEN(sched_rr_get_interval)
146
147#else
148
149/* Configured in kernel version:
150 */
151static struct ksched *ksched;
152
153static int sched_attach(void)
154{
155	int ret = ksched_attach(&ksched);
156
157	if (ret == 0)
158		p31b_setcfg(CTL_P1003_1B_PRIORITY_SCHEDULING, 1);
159
160	return ret;
161}
162
163int sched_setparam(struct proc *p,
164	struct sched_setparam_args *uap)
165{
166	int e;
167
168	struct sched_param sched_param;
169	copyin(uap->param, &sched_param, sizeof(sched_param));
170
171	(void) (0
172	|| (e = p31b_proc(p, uap->pid, &p))
173	|| (e = ksched_setparam(&p->p_retval[0], ksched, p,
174		(const struct sched_param *)&sched_param))
175	);
176
177	return e;
178}
179
180int sched_getparam(struct proc *p,
181	struct sched_getparam_args *uap)
182{
183	int e;
184	struct sched_param sched_param;
185
186	(void) (0
187	|| (e = p31b_proc(p, uap->pid, &p))
188	|| (e = ksched_getparam(&p->p_retval[0], ksched, p, &sched_param))
189	);
190
191	if (!e)
192		copyout(&sched_param, uap->param, sizeof(sched_param));
193
194	return e;
195}
196int sched_setscheduler(struct proc *p,
197	struct sched_setscheduler_args *uap)
198{
199	int e;
200
201	struct sched_param sched_param;
202	copyin(uap->param, &sched_param, sizeof(sched_param));
203
204	(void) (0
205	|| (e = p31b_proc(p, uap->pid, &p))
206	|| (e = ksched_setscheduler(&p->p_retval[0],
207	ksched, p, uap->policy,
208		(const struct sched_param *)&sched_param))
209	);
210
211	return e;
212}
213int sched_getscheduler(struct proc *p,
214	struct sched_getscheduler_args *uap)
215{
216	int e;
217	(void) (0
218	|| (e = p31b_proc(p, uap->pid, &p))
219	|| (e = ksched_getscheduler(&p->p_retval[0], ksched, p))
220	);
221
222	return e;
223}
224int sched_yield(struct proc *p,
225	struct sched_yield_args *uap)
226{
227	return ksched_yield(&p->p_retval[0], ksched);
228}
229int sched_get_priority_max(struct proc *p,
230	struct sched_get_priority_max_args *uap)
231{
232	return ksched_get_priority_max(&p->p_retval[0],
233	ksched, uap->policy);
234}
235int sched_get_priority_min(struct proc *p,
236	struct sched_get_priority_min_args *uap)
237{
238	return ksched_get_priority_min(&p->p_retval[0],
239	ksched, uap->policy);
240}
241int sched_rr_get_interval(struct proc *p,
242	struct sched_rr_get_interval_args *uap)
243{
244	int e;
245
246	(void) (0
247	|| (e = p31b_proc(p, uap->pid, &p))
248	|| (e = ksched_rr_get_interval(&p->p_retval[0], ksched,
249	p, uap->interval))
250	);
251
252	return e;
253}
254
255#endif
256
257static void p31binit(void *notused)
258{
259	(void) sched_attach();
260	p31b_setcfg(CTL_P1003_1B_PAGESIZE, PAGE_SIZE);
261}
262
263SYSINIT(p31b, SI_SUB_P1003_1B, SI_ORDER_FIRST, p31binit, NULL);
264