1 /* $OpenBSD: subr_prof.c,v 1.33 2023/04/25 01:32:36 cheloha 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 u_int gmon_cpu_count; /* [K] number of CPUs with profiling enabled */ 59 60 extern char etext[]; 61 62 void 63 prof_init(void) 64 { 65 CPU_INFO_ITERATOR cii; 66 struct cpu_info *ci; 67 struct gmonparam *p; 68 u_long lowpc, highpc, textsize; 69 u_long kcountsize, fromssize, tossize; 70 long tolimit; 71 char *cp; 72 int size; 73 74 /* 75 * Round lowpc and highpc to multiples of the density we're using 76 * so the rest of the scaling (here and in gprof) stays in ints. 77 */ 78 lowpc = ROUNDDOWN(KERNBASE, HISTFRACTION * sizeof(HISTCOUNTER)); 79 highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER)); 80 textsize = highpc - lowpc; 81 #ifdef GPROF 82 printf("Profiling kernel, textsize=%ld [%lx..%lx]\n", 83 textsize, lowpc, highpc); 84 #endif 85 kcountsize = textsize / HISTFRACTION; 86 fromssize = textsize / HASHFRACTION; 87 tolimit = textsize * ARCDENSITY / 100; 88 if (tolimit < MINARCS) 89 tolimit = MINARCS; 90 else if (tolimit > MAXARCS) 91 tolimit = MAXARCS; 92 tossize = tolimit * sizeof(struct tostruct); 93 size = sizeof(*p) + kcountsize + fromssize + tossize; 94 95 /* Allocate and initialize one profiling buffer per CPU. */ 96 CPU_INFO_FOREACH(cii, ci) { 97 cp = km_alloc(round_page(size), &kv_any, &kp_zero, &kd_nowait); 98 if (cp == NULL) { 99 printf("No memory for profiling.\n"); 100 return; 101 } 102 103 p = (struct gmonparam *)cp; 104 cp += sizeof(*p); 105 p->tos = (struct tostruct *)cp; 106 cp += tossize; 107 p->kcount = (u_short *)cp; 108 cp += kcountsize; 109 p->froms = (u_short *)cp; 110 111 p->state = GMON_PROF_OFF; 112 p->lowpc = lowpc; 113 p->highpc = highpc; 114 p->textsize = textsize; 115 p->hashfraction = HASHFRACTION; 116 p->kcountsize = kcountsize; 117 p->fromssize = fromssize; 118 p->tolimit = tolimit; 119 p->tossize = tossize; 120 121 ci->ci_gmon = p; 122 } 123 } 124 125 int 126 prof_state_toggle(struct gmonparam *gp, int oldstate) 127 { 128 int error = 0; 129 130 KERNEL_ASSERT_LOCKED(); 131 132 if (gp->state == oldstate) 133 return (0); 134 135 switch (gp->state) { 136 case GMON_PROF_ON: 137 #if !defined(GPROF) 138 /* 139 * If this is not a profiling kernel, we need to patch 140 * all symbols that can be instrummented. 141 */ 142 error = db_prof_enable(); 143 #endif 144 if (error == 0) { 145 if (++gmon_cpu_count == 1) 146 startprofclock(&process0); 147 } 148 break; 149 default: 150 error = EINVAL; 151 gp->state = GMON_PROF_OFF; 152 /* FALLTHROUGH */ 153 case GMON_PROF_OFF: 154 if (--gmon_cpu_count == 0) 155 stopprofclock(&process0); 156 #if !defined(GPROF) 157 db_prof_disable(); 158 #endif 159 break; 160 } 161 162 return (error); 163 } 164 165 /* 166 * Return kernel profiling information. 167 */ 168 int 169 sysctl_doprof(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, 170 size_t newlen) 171 { 172 CPU_INFO_ITERATOR cii; 173 struct cpu_info *ci; 174 struct gmonparam *gp = NULL; 175 int error, cpuid, op, state; 176 177 /* all sysctl names at this level are name and field */ 178 if (namelen != 2) 179 return (ENOTDIR); /* overloaded */ 180 181 op = name[0]; 182 cpuid = name[1]; 183 184 CPU_INFO_FOREACH(cii, ci) { 185 if (cpuid == CPU_INFO_UNIT(ci)) { 186 gp = ci->ci_gmon; 187 break; 188 } 189 } 190 191 if (gp == NULL) 192 return (EOPNOTSUPP); 193 194 /* Assume that if we're here it is safe to execute profiling. */ 195 gmoninit = 1; 196 197 switch (op) { 198 case GPROF_STATE: 199 state = gp->state; 200 error = sysctl_int(oldp, oldlenp, newp, newlen, &gp->state); 201 if (error) 202 return (error); 203 return (prof_state_toggle(gp, state)); 204 case GPROF_COUNT: 205 return (sysctl_struct(oldp, oldlenp, newp, newlen, 206 gp->kcount, gp->kcountsize)); 207 case GPROF_FROMS: 208 return (sysctl_struct(oldp, oldlenp, newp, newlen, 209 gp->froms, gp->fromssize)); 210 case GPROF_TOS: 211 return (sysctl_struct(oldp, oldlenp, newp, newlen, 212 gp->tos, gp->tossize)); 213 case GPROF_GMONPARAM: 214 return (sysctl_rdstruct(oldp, oldlenp, newp, gp, sizeof *gp)); 215 default: 216 return (EOPNOTSUPP); 217 } 218 /* NOTREACHED */ 219 } 220 #endif /* GPROF || DDBPROF */ 221 222 /* 223 * Profiling system call. 224 * 225 * The scale factor is a fixed point number with 16 bits of fraction, so that 226 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling. 227 */ 228 int 229 sys_profil(struct proc *p, void *v, register_t *retval) 230 { 231 struct sys_profil_args /* { 232 syscallarg(caddr_t) samples; 233 syscallarg(size_t) size; 234 syscallarg(u_long) offset; 235 syscallarg(u_int) scale; 236 } */ *uap = v; 237 struct process *pr = p->p_p; 238 struct uprof *upp; 239 int s; 240 241 if (SCARG(uap, scale) > (1 << 16)) 242 return (EINVAL); 243 if (SCARG(uap, scale) == 0) { 244 stopprofclock(pr); 245 return (0); 246 } 247 upp = &pr->ps_prof; 248 249 /* Block profile interrupts while changing state. */ 250 s = splstatclock(); 251 upp->pr_off = SCARG(uap, offset); 252 upp->pr_scale = SCARG(uap, scale); 253 upp->pr_base = (caddr_t)SCARG(uap, samples); 254 upp->pr_size = SCARG(uap, size); 255 startprofclock(pr); 256 splx(s); 257 258 return (0); 259 } 260 261 /* 262 * Scale is a fixed-point number with the binary point 16 bits 263 * into the value, and is <= 1.0. pc is at most 32 bits, so the 264 * intermediate result is at most 48 bits. 265 */ 266 #define PC_TO_INDEX(pc, prof) \ 267 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \ 268 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1) 269 270 /* 271 * Collect user-level profiling statistics; called on a profiling tick, 272 * when a process is running in user-mode. This routine may be called 273 * from an interrupt context. Schedule an AST that will vector us to 274 * trap() with a context in which copyin and copyout will work. 275 * Trap will then call addupc_task(). 276 */ 277 void 278 addupc_intr(struct proc *p, u_long pc, u_long nticks) 279 { 280 struct uprof *prof; 281 282 prof = &p->p_p->ps_prof; 283 if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size) 284 return; /* out of range; ignore */ 285 286 p->p_prof_addr = pc; 287 p->p_prof_ticks += nticks; 288 atomic_setbits_int(&p->p_flag, P_OWEUPC); 289 need_proftick(p); 290 } 291 292 293 /* 294 * Much like before, but we can afford to take faults here. If the 295 * update fails, we simply turn off profiling. 296 */ 297 void 298 addupc_task(struct proc *p, u_long pc, u_int nticks) 299 { 300 struct process *pr = p->p_p; 301 struct uprof *prof; 302 caddr_t addr; 303 u_int i; 304 u_short v; 305 306 /* Testing PS_PROFIL may be unnecessary, but is certainly safe. */ 307 if ((pr->ps_flags & PS_PROFIL) == 0 || nticks == 0) 308 return; 309 310 prof = &pr->ps_prof; 311 if (pc < prof->pr_off || 312 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) 313 return; 314 315 addr = prof->pr_base + i; 316 if (copyin(addr, (caddr_t)&v, sizeof(v)) == 0) { 317 v += nticks; 318 if (copyout((caddr_t)&v, addr, sizeof(v)) == 0) 319 return; 320 } 321 stopprofclock(pr); 322 } 323