1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/sysproto.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/proc.h> 39 #include <sys/resourcevar.h> 40 #include <sys/sysctl.h> 41 42 #include <machine/cpu.h> 43 44 /* 45 * Profiling system call. 46 * 47 * The scale factor is a fixed point number with 16 bits of fraction, so that 48 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 49 */ 50 #ifndef _SYS_SYSPROTO_H_ 51 struct profil_args { 52 caddr_t samples; 53 size_t size; 54 size_t offset; 55 u_int scale; 56 }; 57 #endif 58 /* ARGSUSED */ 59 int 60 sys_profil(struct thread *td, struct profil_args *uap) 61 { 62 struct uprof *upp; 63 struct proc *p; 64 65 if (uap->scale > (1 << 16)) 66 return (EINVAL); 67 68 p = td->td_proc; 69 if (uap->scale == 0) { 70 PROC_LOCK(p); 71 stopprofclock(p); 72 PROC_UNLOCK(p); 73 return (0); 74 } 75 PROC_LOCK(p); 76 upp = &td->td_proc->p_stats->p_prof; 77 PROC_PROFLOCK(p); 78 upp->pr_off = uap->offset; 79 upp->pr_scale = uap->scale; 80 upp->pr_base = uap->samples; 81 upp->pr_size = uap->size; 82 PROC_PROFUNLOCK(p); 83 startprofclock(p); 84 PROC_UNLOCK(p); 85 86 return (0); 87 } 88 89 /* 90 * Scale is a fixed-point number with the binary point 16 bits 91 * into the value, and is <= 1.0. pc is at most 32 bits, so the 92 * intermediate result is at most 48 bits. 93 */ 94 #define PC_TO_INDEX(pc, prof) \ 95 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 96 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 97 98 /* 99 * Collect user-level profiling statistics; called on a profiling tick, 100 * when a process is running in user-mode. This routine may be called 101 * from an interrupt context. We perform the update with an AST 102 * that will vector us to trap() with a context in which copyin and 103 * copyout will work. Trap will then call addupc_task(). 104 * 105 * Note that we may (rarely) not get around to the AST soon enough, and 106 * lose profile ticks when the next tick overwrites this one, but in this 107 * case the system is overloaded and the profile is probably already 108 * inaccurate. 109 */ 110 void 111 addupc_intr(struct thread *td, uintfptr_t pc, u_int ticks) 112 { 113 struct uprof *prof; 114 115 if (ticks == 0) 116 return; 117 prof = &td->td_proc->p_stats->p_prof; 118 PROC_PROFLOCK(td->td_proc); 119 if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size) { 120 PROC_PROFUNLOCK(td->td_proc); 121 return; /* out of range; ignore */ 122 } 123 124 PROC_PROFUNLOCK(td->td_proc); 125 td->td_profil_addr = pc; 126 td->td_profil_ticks = ticks; 127 td->td_pflags |= TDP_OWEUPC; 128 ast_sched(td, TDA_OWEUPC); 129 } 130 131 /* 132 * Actually update the profiling statistics. If the update fails, we 133 * simply turn off profiling. 134 */ 135 void 136 addupc_task(struct thread *td, uintfptr_t pc, u_int ticks) 137 { 138 struct proc *p = td->td_proc; 139 struct uprof *prof; 140 caddr_t addr; 141 u_int i; 142 u_short v; 143 int stop = 0; 144 145 if (ticks == 0) 146 return; 147 148 PROC_LOCK(p); 149 if (!(p->p_flag & P_PROFIL)) { 150 PROC_UNLOCK(p); 151 return; 152 } 153 p->p_profthreads++; 154 prof = &p->p_stats->p_prof; 155 PROC_PROFLOCK(p); 156 if (pc < prof->pr_off || 157 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) { 158 PROC_PROFUNLOCK(p); 159 goto out; 160 } 161 162 addr = prof->pr_base + i; 163 PROC_PROFUNLOCK(p); 164 PROC_UNLOCK(p); 165 if (copyin(addr, &v, sizeof(v)) == 0) { 166 v += ticks; 167 if (copyout(&v, addr, sizeof(v)) == 0) { 168 PROC_LOCK(p); 169 goto out; 170 } 171 } 172 stop = 1; 173 PROC_LOCK(p); 174 175 out: 176 if (--p->p_profthreads == 0) { 177 if (p->p_flag & P_STOPPROF) { 178 wakeup(&p->p_profthreads); 179 p->p_flag &= ~P_STOPPROF; 180 stop = 0; 181 } 182 } 183 if (stop) 184 stopprofclock(p); 185 PROC_UNLOCK(p); 186 } 187