1 /* $OpenBSD: subr_prof.c,v 1.26 2014/07/08 17:19:25 deraadt Exp $ */ 2 /* $NetBSD: subr_prof.c,v 1.12 1996/04/22 01:38:50 christos Exp $ */ 3 4 /*- 5 * Copyright (c) 1982, 1986, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its 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 THE REGENTS 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 THE REGENTS 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 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/kernel.h> 38 #include <sys/proc.h> 39 #include <sys/resourcevar.h> 40 #include <sys/mount.h> 41 #include <sys/sysctl.h> 42 #include <sys/syscallargs.h> 43 44 45 #ifdef GPROF 46 #include <sys/malloc.h> 47 #include <sys/gmon.h> 48 49 /* 50 * Flag to prevent CPUs from executing the mcount() monitor function 51 * until we're sure they are in a sane state. 52 */ 53 int gmoninit = 0; 54 55 extern char etext[]; 56 57 void 58 kmstartup(void) 59 { 60 CPU_INFO_ITERATOR cii; 61 struct cpu_info *ci; 62 struct gmonparam *p; 63 u_long lowpc, highpc, textsize; 64 u_long kcountsize, fromssize, tossize; 65 long tolimit; 66 char *cp; 67 int size; 68 69 /* 70 * Round lowpc and highpc to multiples of the density we're using 71 * so the rest of the scaling (here and in gprof) stays in ints. 72 */ 73 lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER)); 74 highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 75 textsize = highpc - lowpc; 76 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 77 textsize, lowpc, highpc); 78 kcountsize = textsize / HISTFRACTION; 79 fromssize = textsize / HASHFRACTION; 80 tolimit = textsize * ARCDENSITY / 100; 81 if (tolimit < MINARCS) 82 tolimit = MINARCS; 83 else if (tolimit > MAXARCS) 84 tolimit = MAXARCS; 85 tossize = tolimit * sizeof(struct tostruct); 86 size = sizeof(*p) + kcountsize + fromssize + tossize; 87 88 /* Allocate and initialize one profiling buffer per CPU. */ 89 CPU_INFO_FOREACH(cii, ci) { 90 cp = km_alloc(round_page(size), &kv_any, &kp_zero, &kd_nowait); 91 if (cp == NULL) { 92 printf("No memory for profiling.\n"); 93 return; 94 } 95 96 p = (struct gmonparam *)cp; 97 cp += sizeof(*p); 98 p->tos = (struct tostruct *)cp; 99 cp += tossize; 100 p->kcount = (u_short *)cp; 101 cp += kcountsize; 102 p->froms = (u_short *)cp; 103 104 p->state = GMON_PROF_OFF; 105 p->lowpc = lowpc; 106 p->highpc = highpc; 107 p->textsize = textsize; 108 p->hashfraction = HASHFRACTION; 109 p->kcountsize = kcountsize; 110 p->fromssize = fromssize; 111 p->tolimit = tolimit; 112 p->tossize = tossize; 113 114 ci->ci_gmon = p; 115 } 116 } 117 118 /* 119 * Return kernel profiling information. 120 */ 121 int 122 sysctl_doprof(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 123 size_t newlen) 124 { 125 CPU_INFO_ITERATOR cii; 126 struct cpu_info *ci; 127 struct gmonparam *gp = NULL; 128 int error, cpuid, op; 129 130 /* all sysctl names at this level are name and field */ 131 if (namelen != 2) 132 return (ENOTDIR); /* overloaded */ 133 134 op = name[0]; 135 cpuid = name[1]; 136 137 CPU_INFO_FOREACH(cii, ci) { 138 if (cpuid == CPU_INFO_UNIT(ci)) { 139 gp = ci->ci_gmon; 140 break; 141 } 142 } 143 144 if (gp == NULL) 145 return (EOPNOTSUPP); 146 147 /* Assume that if we're here it is safe to execute profiling. */ 148 gmoninit = 1; 149 150 switch (op) { 151 case GPROF_STATE: 152 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 153 if (error) 154 return (error); 155 if (gp->state == GMON_PROF_OFF) 156 stopprofclock(&process0); 157 else 158 startprofclock(&process0); 159 return (0); 160 case GPROF_COUNT: 161 return (sysctl_struct(oldp, oldlenp, newp, newlen, 162 gp->kcount, gp->kcountsize)); 163 case GPROF_FROMS: 164 return (sysctl_struct(oldp, oldlenp, newp, newlen, 165 gp->froms, gp->fromssize)); 166 case GPROF_TOS: 167 return (sysctl_struct(oldp, oldlenp, newp, newlen, 168 gp->tos, gp->tossize)); 169 case GPROF_GMONPARAM: 170 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp)); 171 default: 172 return (EOPNOTSUPP); 173 } 174 /* NOTREACHED */ 175 } 176 #endif /* GPROF */ 177 178 /* 179 * Profiling system call. 180 * 181 * The scale factor is a fixed point number with 16 bits of fraction, so that 182 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 183 */ 184 /* ARGSUSED */ 185 int 186 sys_profil(struct proc *p, void *v, register_t *retval) 187 { 188 struct sys_profil_args /* { 189 syscallarg(caddr_t) samples; 190 syscallarg(size_t) size; 191 syscallarg(u_long) offset; 192 syscallarg(u_int) scale; 193 } */ *uap = v; 194 struct process *pr = p->p_p; 195 struct uprof *upp; 196 int s; 197 198 if (SCARG(uap, scale) > (1 << 16)) 199 return (EINVAL); 200 if (SCARG(uap, scale) == 0) { 201 stopprofclock(pr); 202 return (0); 203 } 204 upp = &pr->ps_prof; 205 206 /* Block profile interrupts while changing state. */ 207 s = splstatclock(); 208 upp->pr_off = SCARG(uap, offset); 209 upp->pr_scale = SCARG(uap, scale); 210 upp->pr_base = (caddr_t)SCARG(uap, samples); 211 upp->pr_size = SCARG(uap, size); 212 startprofclock(pr); 213 splx(s); 214 215 return (0); 216 } 217 218 /* 219 * Scale is a fixed-point number with the binary point 16 bits 220 * into the value, and is <= 1.0. pc is at most 32 bits, so the 221 * intermediate result is at most 48 bits. 222 */ 223 #define PC_TO_INDEX(pc, prof) \ 224 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 225 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 226 227 /* 228 * Collect user-level profiling statistics; called on a profiling tick, 229 * when a process is running in user-mode. This routine may be called 230 * from an interrupt context. Schedule an AST that will vector us to 231 * trap() with a context in which copyin and copyout will work. 232 * Trap will then call addupc_task(). 233 */ 234 void 235 addupc_intr(struct proc *p, u_long pc) 236 { 237 struct uprof *prof; 238 239 prof = &p->p_p->ps_prof; 240 if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size) 241 return; /* out of range; ignore */ 242 243 p->p_prof_addr = pc; 244 p->p_prof_ticks++; 245 atomic_setbits_int(&p->p_flag, P_OWEUPC); 246 need_proftick(p); 247 } 248 249 250 /* 251 * Much like before, but we can afford to take faults here. If the 252 * update fails, we simply turn off profiling. 253 */ 254 void 255 addupc_task(struct proc *p, u_long pc, u_int nticks) 256 { 257 struct process *pr = p->p_p; 258 struct uprof *prof; 259 caddr_t addr; 260 u_int i; 261 u_short v; 262 263 /* Testing PS_PROFIL may be unnecessary, but is certainly safe. */ 264 if ((pr->ps_flags & PS_PROFIL) == 0 || nticks == 0) 265 return; 266 267 prof = &pr->ps_prof; 268 if (pc < prof->pr_off || 269 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 270 return; 271 272 addr = prof->pr_base + i; 273 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 274 v += nticks; 275 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 276 return; 277 } 278 stopprofclock(pr); 279 } 280