1 /** $MirOS: src/sys/kern/subr_prof.c,v 1.2 2005/03/06 21:28:03 tg Exp $ */
2 /* $OpenBSD: subr_prof.c,v 1.14 2003/09/01 18:06:03 henning Exp $ */
3 /* $NetBSD: subr_prof.c,v 1.12 1996/04/22 01:38:50 christos Exp $ */
4
5 /*-
6 * Copyright (c) 1982, 1986, 1993
7 * The Regents of the University of California. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93
34 */
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/proc.h>
40 #include <sys/user.h>
41 #include <sys/mount.h>
42 #include <sys/syscallargs.h>
43
44 #include <machine/cpu.h>
45
46 /*
47 * Profiling system call.
48 *
49 * The scale factor is a fixed point number with 16 bits of fraction, so that
50 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling.
51 */
52 /* ARGSUSED */
53 int
sys_profil(p,v,retval)54 sys_profil(p, v, retval)
55 struct proc *p;
56 void *v;
57 register_t *retval;
58 {
59 register struct sys_profil_args /* {
60 syscallarg(caddr_t) samples;
61 syscallarg(size_t) size;
62 syscallarg(u_long) offset;
63 syscallarg(u_int) scale;
64 } */ *uap = v;
65 register struct uprof *upp;
66 int s;
67
68 if (SCARG(uap, scale) > (1 << 16))
69 return (EINVAL);
70 if (SCARG(uap, scale) == 0) {
71 stopprofclock(p);
72 return (0);
73 }
74 upp = &p->p_stats->p_prof;
75
76 /* Block profile interrupts while changing state. */
77 s = splstatclock();
78 upp->pr_off = SCARG(uap, offset);
79 upp->pr_scale = SCARG(uap, scale);
80 upp->pr_base = (caddr_t)SCARG(uap, samples);
81 upp->pr_size = SCARG(uap, size);
82 startprofclock(p);
83 splx(s);
84
85 return (0);
86 }
87
88 /*
89 * Scale is a fixed-point number with the binary point 16 bits
90 * into the value, and is <= 1.0. pc is at most 32 bits, so the
91 * intermediate result is at most 48 bits.
92 */
93 #define PC_TO_INDEX(pc, prof) \
94 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
95 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
96
97 /*
98 * Collect user-level profiling statistics; called on a profiling tick,
99 * when a process is running in user-mode. This routine may be called
100 * from an interrupt context. Schedule an AST that will vector us to
101 * trap() with a context in which copyin and copyout will work.
102 * Trap will then call addupc_task().
103 */
104 void
addupc_intr(struct proc * p,u_long pc)105 addupc_intr(struct proc *p, u_long pc)
106 {
107 struct uprof *prof;
108
109 prof = &p->p_stats->p_prof;
110 if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size)
111 return; /* out of range; ignore */
112
113 prof->pr_addr = pc;
114 need_proftick(p);
115 }
116
117
118 /*
119 * Much like before, but we can afford to take faults here. If the
120 * update fails, we simply turn off profiling.
121 */
122 void
addupc_task(struct proc * p,u_long pc,u_int nticks)123 addupc_task(struct proc *p, u_long pc, u_int nticks)
124 {
125 struct uprof *prof;
126 caddr_t addr;
127 u_int i;
128 u_short v;
129
130 /* Testing P_PROFIL may be unnecessary, but is certainly safe. */
131 if ((p->p_flag & P_PROFIL) == 0 || nticks == 0)
132 return;
133
134 prof = &p->p_stats->p_prof;
135 if (pc < prof->pr_off ||
136 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
137 return;
138
139 addr = prof->pr_base + i;
140 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) {
141 v += nticks;
142 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0)
143 return;
144 }
145 stopprofclock(p);
146 }
147