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/cdefs.h> 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/sysproto.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/mutex.h> 39 #include <sys/proc.h> 40 #include <sys/resourcevar.h> 41 #include <sys/sysctl.h> 42 43 #include <machine/cpu.h> 44 45 /* 46 * Profiling system call. 47 * 48 * The scale factor is a fixed point number with 16 bits of fraction, so that 49 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 50 */ 51 #ifndef _SYS_SYSPROTO_H_ 52 struct profil_args { 53 caddr_t samples; 54 size_t size; 55 size_t offset; 56 u_int scale; 57 }; 58 #endif 59 /* ARGSUSED */ 60 int 61 sys_profil(struct thread *td, struct profil_args *uap) 62 { 63 struct uprof *upp; 64 struct proc *p; 65 66 if (uap->scale > (1 << 16)) 67 return (EINVAL); 68 69 p = td->td_proc; 70 if (uap->scale == 0) { 71 PROC_LOCK(p); 72 stopprofclock(p); 73 PROC_UNLOCK(p); 74 return (0); 75 } 76 PROC_LOCK(p); 77 upp = &td->td_proc->p_stats->p_prof; 78 PROC_PROFLOCK(p); 79 upp->pr_off = uap->offset; 80 upp->pr_scale = uap->scale; 81 upp->pr_base = uap->samples; 82 upp->pr_size = uap->size; 83 PROC_PROFUNLOCK(p); 84 startprofclock(p); 85 PROC_UNLOCK(p); 86 87 return (0); 88 } 89 90 /* 91 * Scale is a fixed-point number with the binary point 16 bits 92 * into the value, and is <= 1.0. pc is at most 32 bits, so the 93 * intermediate result is at most 48 bits. 94 */ 95 #define PC_TO_INDEX(pc, prof) \ 96 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 97 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 98 99 /* 100 * Collect user-level profiling statistics; called on a profiling tick, 101 * when a process is running in user-mode. This routine may be called 102 * from an interrupt context. We perform the update with an AST 103 * that will vector us to trap() with a context in which copyin and 104 * copyout will work. Trap will then call addupc_task(). 105 * 106 * Note that we may (rarely) not get around to the AST soon enough, and 107 * lose profile ticks when the next tick overwrites this one, but in this 108 * case the system is overloaded and the profile is probably already 109 * inaccurate. 110 */ 111 void 112 addupc_intr(struct thread *td, uintfptr_t pc, u_int ticks) 113 { 114 struct uprof *prof; 115 116 if (ticks == 0) 117 return; 118 prof = &td->td_proc->p_stats->p_prof; 119 PROC_PROFLOCK(td->td_proc); 120 if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size) { 121 PROC_PROFUNLOCK(td->td_proc); 122 return; /* out of range; ignore */ 123 } 124 125 PROC_PROFUNLOCK(td->td_proc); 126 td->td_profil_addr = pc; 127 td->td_profil_ticks = ticks; 128 td->td_pflags |= TDP_OWEUPC; 129 ast_sched(td, TDA_OWEUPC); 130 } 131 132 /* 133 * Actually update the profiling statistics. If the update fails, we 134 * simply turn off profiling. 135 */ 136 void 137 addupc_task(struct thread *td, uintfptr_t pc, u_int ticks) 138 { 139 struct proc *p = td->td_proc; 140 struct uprof *prof; 141 caddr_t addr; 142 u_int i; 143 u_short v; 144 int stop = 0; 145 146 if (ticks == 0) 147 return; 148 149 PROC_LOCK(p); 150 if (!(p->p_flag & P_PROFIL)) { 151 PROC_UNLOCK(p); 152 return; 153 } 154 p->p_profthreads++; 155 prof = &p->p_stats->p_prof; 156 PROC_PROFLOCK(p); 157 if (pc < prof->pr_off || 158 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) { 159 PROC_PROFUNLOCK(p); 160 goto out; 161 } 162 163 addr = prof->pr_base + i; 164 PROC_PROFUNLOCK(p); 165 PROC_UNLOCK(p); 166 if (copyin(addr, &v, sizeof(v)) == 0) { 167 v += ticks; 168 if (copyout(&v, addr, sizeof(v)) == 0) { 169 PROC_LOCK(p); 170 goto out; 171 } 172 } 173 stop = 1; 174 PROC_LOCK(p); 175 176 out: 177 if (--p->p_profthreads == 0) { 178 if (p->p_flag & P_STOPPROF) { 179 wakeup(&p->p_profthreads); 180 p->p_flag &= ~P_STOPPROF; 181 stop = 0; 182 } 183 } 184 if (stop) 185 stopprofclock(p); 186 PROC_UNLOCK(p); 187 } 188