1 /* $OpenBSD: subr_prof.c,v 1.30 2016/09/04 09:22:29 mpi 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/proc.h> 38 #include <sys/resourcevar.h> 39 #include <sys/mount.h> 40 #include <sys/sysctl.h> 41 #include <sys/syscallargs.h> 42 43 44 #if defined(GPROF) || defined(DDBPROF) 45 #include <sys/malloc.h> 46 #include <sys/gmon.h> 47 48 #include <uvm/uvm_extern.h> 49 50 #include <machine/db_machdep.h> 51 #include <ddb/db_extern.h> 52 53 /* 54 * Flag to prevent CPUs from executing the mcount() monitor function 55 * until we're sure they are in a sane state. 56 */ 57 int gmoninit = 0; 58 59 extern char etext[]; 60 61 void 62 prof_init(void) 63 { 64 CPU_INFO_ITERATOR cii; 65 struct cpu_info *ci; 66 struct gmonparam *p; 67 u_long lowpc, highpc, textsize; 68 u_long kcountsize, fromssize, tossize; 69 long tolimit; 70 char *cp; 71 int size; 72 73 #if !defined(GPROF) && defined(DDBPROF) 74 db_prof_init(); 75 #endif 76 77 /* 78 * Round lowpc and highpc to multiples of the density we're using 79 * so the rest of the scaling (here and in gprof) stays in ints. 80 */ 81 lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER)); 82 highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 83 textsize = highpc - lowpc; 84 #ifdef GPROF 85 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 86 textsize, lowpc, highpc); 87 #endif 88 kcountsize = textsize / HISTFRACTION; 89 fromssize = textsize / HASHFRACTION; 90 tolimit = textsize * ARCDENSITY / 100; 91 if (tolimit < MINARCS) 92 tolimit = MINARCS; 93 else if (tolimit > MAXARCS) 94 tolimit = MAXARCS; 95 tossize = tolimit * sizeof(struct tostruct); 96 size = sizeof(*p) + kcountsize + fromssize + tossize; 97 98 /* Allocate and initialize one profiling buffer per CPU. */ 99 CPU_INFO_FOREACH(cii, ci) { 100 cp = km_alloc(round_page(size), &kv_any, &kp_zero, &kd_nowait); 101 if (cp == NULL) { 102 printf("No memory for profiling.\n"); 103 return; 104 } 105 106 p = (struct gmonparam *)cp; 107 cp += sizeof(*p); 108 p->tos = (struct tostruct *)cp; 109 cp += tossize; 110 p->kcount = (u_short *)cp; 111 cp += kcountsize; 112 p->froms = (u_short *)cp; 113 114 p->state = GMON_PROF_OFF; 115 p->lowpc = lowpc; 116 p->highpc = highpc; 117 p->textsize = textsize; 118 p->hashfraction = HASHFRACTION; 119 p->kcountsize = kcountsize; 120 p->fromssize = fromssize; 121 p->tolimit = tolimit; 122 p->tossize = tossize; 123 124 ci->ci_gmon = p; 125 } 126 } 127 128 int 129 prof_state_toggle(struct gmonparam *gp, int oldstate) 130 { 131 int error = 0; 132 133 if (gp->state == oldstate) 134 return (0); 135 136 switch (gp->state) { 137 case GMON_PROF_ON: 138 #if !defined(GPROF) 139 /* 140 * If this is not a profiling kernel, we need to patch 141 * all symbols that can be instrummented. 142 */ 143 error = db_prof_enable(); 144 #endif 145 if (error == 0) 146 startprofclock(&process0); 147 break; 148 default: 149 error = EINVAL; 150 gp->state = GMON_PROF_OFF; 151 /* FALLTHROUGH */ 152 case GMON_PROF_OFF: 153 stopprofclock(&process0); 154 #if !defined(GPROF) 155 db_prof_disable(); 156 #endif 157 break; 158 } 159 160 return (error); 161 } 162 163 /* 164 * Return kernel profiling information. 165 */ 166 int 167 sysctl_doprof(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 168 size_t newlen) 169 { 170 CPU_INFO_ITERATOR cii; 171 struct cpu_info *ci; 172 struct gmonparam *gp = NULL; 173 int error, cpuid, op, state; 174 175 /* all sysctl names at this level are name and field */ 176 if (namelen != 2) 177 return (ENOTDIR); /* overloaded */ 178 179 op = name[0]; 180 cpuid = name[1]; 181 182 CPU_INFO_FOREACH(cii, ci) { 183 if (cpuid == CPU_INFO_UNIT(ci)) { 184 gp = ci->ci_gmon; 185 break; 186 } 187 } 188 189 if (gp == NULL) 190 return (EOPNOTSUPP); 191 192 /* Assume that if we're here it is safe to execute profiling. */ 193 gmoninit = 1; 194 195 switch (op) { 196 case GPROF_STATE: 197 state = gp->state; 198 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 199 if (error) 200 return (error); 201 return (prof_state_toggle(gp, state)); 202 case GPROF_COUNT: 203 return (sysctl_struct(oldp, oldlenp, newp, newlen, 204 gp->kcount, gp->kcountsize)); 205 case GPROF_FROMS: 206 return (sysctl_struct(oldp, oldlenp, newp, newlen, 207 gp->froms, gp->fromssize)); 208 case GPROF_TOS: 209 return (sysctl_struct(oldp, oldlenp, newp, newlen, 210 gp->tos, gp->tossize)); 211 case GPROF_GMONPARAM: 212 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp)); 213 default: 214 return (EOPNOTSUPP); 215 } 216 /* NOTREACHED */ 217 } 218 #endif /* GPROF || DDBPROF */ 219 220 /* 221 * Profiling system call. 222 * 223 * The scale factor is a fixed point number with 16 bits of fraction, so that 224 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 225 */ 226 int 227 sys_profil(struct proc *p, void *v, register_t *retval) 228 { 229 struct sys_profil_args /* { 230 syscallarg(caddr_t) samples; 231 syscallarg(size_t) size; 232 syscallarg(u_long) offset; 233 syscallarg(u_int) scale; 234 } */ *uap = v; 235 struct process *pr = p->p_p; 236 struct uprof *upp; 237 int s; 238 239 if (SCARG(uap, scale) > (1 << 16)) 240 return (EINVAL); 241 if (SCARG(uap, scale) == 0) { 242 stopprofclock(pr); 243 return (0); 244 } 245 upp = &pr->ps_prof; 246 247 /* Block profile interrupts while changing state. */ 248 s = splstatclock(); 249 upp->pr_off = SCARG(uap, offset); 250 upp->pr_scale = SCARG(uap, scale); 251 upp->pr_base = (caddr_t)SCARG(uap, samples); 252 upp->pr_size = SCARG(uap, size); 253 startprofclock(pr); 254 splx(s); 255 256 return (0); 257 } 258 259 /* 260 * Scale is a fixed-point number with the binary point 16 bits 261 * into the value, and is <= 1.0. pc is at most 32 bits, so the 262 * intermediate result is at most 48 bits. 263 */ 264 #define PC_TO_INDEX(pc, prof) \ 265 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 266 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 267 268 /* 269 * Collect user-level profiling statistics; called on a profiling tick, 270 * when a process is running in user-mode. This routine may be called 271 * from an interrupt context. Schedule an AST that will vector us to 272 * trap() with a context in which copyin and copyout will work. 273 * Trap will then call addupc_task(). 274 */ 275 void 276 addupc_intr(struct proc *p, u_long pc) 277 { 278 struct uprof *prof; 279 280 prof = &p->p_p->ps_prof; 281 if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size) 282 return; /* out of range; ignore */ 283 284 p->p_prof_addr = pc; 285 p->p_prof_ticks++; 286 atomic_setbits_int(&p->p_flag, P_OWEUPC); 287 need_proftick(p); 288 } 289 290 291 /* 292 * Much like before, but we can afford to take faults here. If the 293 * update fails, we simply turn off profiling. 294 */ 295 void 296 addupc_task(struct proc *p, u_long pc, u_int nticks) 297 { 298 struct process *pr = p->p_p; 299 struct uprof *prof; 300 caddr_t addr; 301 u_int i; 302 u_short v; 303 304 /* Testing PS_PROFIL may be unnecessary, but is certainly safe. */ 305 if ((pr->ps_flags & PS_PROFIL) == 0 || nticks == 0) 306 return; 307 308 prof = &pr->ps_prof; 309 if (pc < prof->pr_off || 310 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 311 return; 312 313 addr = prof->pr_base + i; 314 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 315 v += nticks; 316 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 317 return; 318 } 319 stopprofclock(pr); 320 } 321