| 1 | /* $NetBSD: mcount.c,v 1.13 2016/02/28 02:56:39 christos Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2003, 2004 Wasabi Systems, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Written by Nathan J. Williams for Wasabi Systems, Inc. |
| 8 | * |
| 9 | * Redistribution and use in source and binary forms, with or without |
| 10 | * modification, are permitted provided that the following conditions |
| 11 | * are met: |
| 12 | * 1. Redistributions of source code must retain the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer. |
| 14 | * 2. Redistributions in binary form must reproduce the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer in the |
| 16 | * documentation and/or other materials provided with the distribution. |
| 17 | * 3. All advertising materials mentioning features or use of this software |
| 18 | * must display the following acknowledgement: |
| 19 | * This product includes software developed for the NetBSD Project by |
| 20 | * Wasabi Systems, Inc. |
| 21 | * 4. The name of Wasabi Systems, Inc. may not be used to endorse |
| 22 | * or promote products derived from this software without specific prior |
| 23 | * written permission. |
| 24 | * |
| 25 | * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND |
| 26 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 27 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 28 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC |
| 29 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 30 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 31 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 32 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 33 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 34 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 35 | * POSSIBILITY OF SUCH DAMAGE. |
| 36 | */ |
| 37 | |
| 38 | /*- |
| 39 | * Copyright (c) 1983, 1992, 1993 |
| 40 | * The Regents of the University of California. All rights reserved. |
| 41 | * |
| 42 | * Redistribution and use in source and binary forms, with or without |
| 43 | * modification, are permitted provided that the following conditions |
| 44 | * are met: |
| 45 | * 1. Redistributions of source code must retain the above copyright |
| 46 | * notice, this list of conditions and the following disclaimer. |
| 47 | * 2. Redistributions in binary form must reproduce the above copyright |
| 48 | * notice, this list of conditions and the following disclaimer in the |
| 49 | * documentation and/or other materials provided with the distribution. |
| 50 | * 3. Neither the name of the University nor the names of its contributors |
| 51 | * may be used to endorse or promote products derived from this software |
| 52 | * without specific prior written permission. |
| 53 | * |
| 54 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 55 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 56 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 57 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 58 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 59 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 60 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 61 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 62 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 63 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 64 | * SUCH DAMAGE. |
| 65 | */ |
| 66 | |
| 67 | /* If building a standalone libkern, don't include mcount. */ |
| 68 | #if (!defined(_KERNEL) || defined(GPROF)) && !defined(_STANDALONE) |
| 69 | |
| 70 | #ifdef _KERNEL_OPT |
| 71 | #include "opt_multiprocessor.h" |
| 72 | #endif |
| 73 | |
| 74 | #include <sys/cdefs.h> |
| 75 | #if !defined(lint) && !defined(_KERNEL) && defined(LIBC_SCCS) |
| 76 | #if 0 |
| 77 | static char sccsid[] = "@(#)mcount.c 8.1 (Berkeley) 6/4/93" ; |
| 78 | #else |
| 79 | __RCSID("$NetBSD: mcount.c,v 1.13 2016/02/28 02:56:39 christos Exp $" ); |
| 80 | #endif |
| 81 | #endif |
| 82 | |
| 83 | #include <sys/param.h> |
| 84 | #include <sys/gmon.h> |
| 85 | #include <sys/lock.h> |
| 86 | |
| 87 | #ifndef _KERNEL |
| 88 | #include "reentrant.h" |
| 89 | #endif |
| 90 | |
| 91 | #ifdef _REENTRANT |
| 92 | extern thread_key_t _gmonkey; |
| 93 | extern struct gmonparam _gmondummy; |
| 94 | struct gmonparam *_m_gmon_alloc(void); |
| 95 | #endif |
| 96 | |
| 97 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) && defined(MULTIPROCESSOR) |
| 98 | __cpu_simple_lock_t __mcount_lock; |
| 99 | #endif |
| 100 | |
| 101 | #ifndef __LINT__ |
| 102 | _MCOUNT_DECL(u_long, u_long) |
| 103 | #ifdef _KERNEL |
| 104 | __attribute__((__no_instrument_function__)) |
| 105 | #endif |
| 106 | __used; |
| 107 | #endif |
| 108 | |
| 109 | /* XXX: make these interfaces */ |
| 110 | #ifdef _RUMPKERNEL |
| 111 | #undef MCOUNT_ENTER |
| 112 | #define MCOUNT_ENTER |
| 113 | #undef MCOUNT_EXIT |
| 114 | #define MCOUNT_EXIT |
| 115 | #undef MCOUNT |
| 116 | #define MCOUNT |
| 117 | #endif |
| 118 | |
| 119 | /* |
| 120 | * mcount is called on entry to each function compiled with the profiling |
| 121 | * switch set. _mcount(), which is declared in a machine-dependent way |
| 122 | * with _MCOUNT_DECL, does the actual work and is either inlined into a |
| 123 | * C routine or called by an assembly stub. In any case, this magic is |
| 124 | * taken care of by the MCOUNT definition in <machine/profile.h>. |
| 125 | * |
| 126 | * _mcount updates data structures that represent traversals of the |
| 127 | * program's call graph edges. frompc and selfpc are the return |
| 128 | * address and function address that represents the given call graph edge. |
| 129 | * |
| 130 | * Note: the original BSD code used the same variable (frompcindex) for |
| 131 | * both frompcindex and frompc. Any reasonable, modern compiler will |
| 132 | * perform this optimization. |
| 133 | */ |
| 134 | #ifndef __LINT__ |
| 135 | /* _mcount; may be static, inline, etc */ |
| 136 | _MCOUNT_DECL(u_long frompc, u_long selfpc) |
| 137 | { |
| 138 | u_short *frompcindex; |
| 139 | struct tostruct *top, *prevtop; |
| 140 | struct gmonparam *p; |
| 141 | long toindex; |
| 142 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
| 143 | int s; |
| 144 | #endif |
| 145 | |
| 146 | #if defined(_REENTRANT) && !defined(_KERNEL) |
| 147 | if (__isthreaded) { |
| 148 | /* prevent re-entry via thr_getspecific */ |
| 149 | if (_gmonparam.state != GMON_PROF_ON) |
| 150 | return; |
| 151 | _gmonparam.state = GMON_PROF_BUSY; |
| 152 | p = thr_getspecific(_gmonkey); |
| 153 | if (p == NULL) { |
| 154 | /* Prevent recursive calls while allocating */ |
| 155 | thr_setspecific(_gmonkey, &_gmondummy); |
| 156 | p = _m_gmon_alloc(); |
| 157 | } |
| 158 | _gmonparam.state = GMON_PROF_ON; |
| 159 | } else |
| 160 | #endif |
| 161 | p = &_gmonparam; |
| 162 | /* |
| 163 | * check that we are profiling |
| 164 | * and that we aren't recursively invoked. |
| 165 | */ |
| 166 | if (p->state != GMON_PROF_ON) |
| 167 | return; |
| 168 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
| 169 | MCOUNT_ENTER; |
| 170 | #ifdef MULTIPROCESSOR |
| 171 | __cpu_simple_lock(&__mcount_lock); |
| 172 | __insn_barrier(); |
| 173 | #endif |
| 174 | #endif |
| 175 | p->state = GMON_PROF_BUSY; |
| 176 | /* |
| 177 | * check that frompcindex is a reasonable pc value. |
| 178 | * for example: signal catchers get called from the stack, |
| 179 | * not from text space. too bad. |
| 180 | */ |
| 181 | frompc -= p->lowpc; |
| 182 | if (frompc > p->textsize) |
| 183 | goto done; |
| 184 | |
| 185 | #if (HASHFRACTION & (HASHFRACTION - 1)) == 0 |
| 186 | if (p->hashfraction == HASHFRACTION) |
| 187 | frompcindex = |
| 188 | &p->froms[ |
| 189 | (size_t)(frompc / (HASHFRACTION * sizeof(*p->froms)))]; |
| 190 | else |
| 191 | #endif |
| 192 | frompcindex = |
| 193 | &p->froms[ |
| 194 | (size_t)(frompc / (p->hashfraction * sizeof(*p->froms)))]; |
| 195 | toindex = *frompcindex; |
| 196 | if (toindex == 0) { |
| 197 | /* |
| 198 | * first time traversing this arc |
| 199 | */ |
| 200 | toindex = ++p->tos[0].link; |
| 201 | if (toindex >= p->tolimit) |
| 202 | /* halt further profiling */ |
| 203 | goto overflow; |
| 204 | |
| 205 | *frompcindex = (u_short)toindex; |
| 206 | top = &p->tos[(size_t)toindex]; |
| 207 | top->selfpc = selfpc; |
| 208 | top->count = 1; |
| 209 | top->link = 0; |
| 210 | goto done; |
| 211 | } |
| 212 | top = &p->tos[(size_t)toindex]; |
| 213 | if (top->selfpc == selfpc) { |
| 214 | /* |
| 215 | * arc at front of chain; usual case. |
| 216 | */ |
| 217 | top->count++; |
| 218 | goto done; |
| 219 | } |
| 220 | /* |
| 221 | * have to go looking down chain for it. |
| 222 | * top points to what we are looking at, |
| 223 | * prevtop points to previous top. |
| 224 | * we know it is not at the head of the chain. |
| 225 | */ |
| 226 | for (; /* goto done */; ) { |
| 227 | if (top->link == 0) { |
| 228 | /* |
| 229 | * top is end of the chain and none of the chain |
| 230 | * had top->selfpc == selfpc. |
| 231 | * so we allocate a new tostruct |
| 232 | * and link it to the head of the chain. |
| 233 | */ |
| 234 | toindex = ++p->tos[0].link; |
| 235 | if (toindex >= p->tolimit) |
| 236 | goto overflow; |
| 237 | |
| 238 | top = &p->tos[(size_t)toindex]; |
| 239 | top->selfpc = selfpc; |
| 240 | top->count = 1; |
| 241 | top->link = *frompcindex; |
| 242 | *frompcindex = (u_short)toindex; |
| 243 | goto done; |
| 244 | } |
| 245 | /* |
| 246 | * otherwise, check the next arc on the chain. |
| 247 | */ |
| 248 | prevtop = top; |
| 249 | top = &p->tos[top->link]; |
| 250 | if (top->selfpc == selfpc) { |
| 251 | /* |
| 252 | * there it is. |
| 253 | * increment its count |
| 254 | * move it to the head of the chain. |
| 255 | */ |
| 256 | top->count++; |
| 257 | toindex = prevtop->link; |
| 258 | prevtop->link = top->link; |
| 259 | top->link = *frompcindex; |
| 260 | *frompcindex = (u_short)toindex; |
| 261 | goto done; |
| 262 | } |
| 263 | } |
| 264 | done: |
| 265 | p->state = GMON_PROF_ON; |
| 266 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
| 267 | #ifdef MULTIPROCESSOR |
| 268 | __insn_barrier(); |
| 269 | __cpu_simple_unlock(&__mcount_lock); |
| 270 | #endif |
| 271 | MCOUNT_EXIT; |
| 272 | #endif |
| 273 | return; |
| 274 | |
| 275 | overflow: |
| 276 | p->state = GMON_PROF_ERROR; |
| 277 | #if defined(_KERNEL) && !defined(_RUMPKERNEL) |
| 278 | #ifdef MULTIPROCESSOR |
| 279 | __insn_barrier(); |
| 280 | __cpu_simple_unlock(&__mcount_lock); |
| 281 | #endif |
| 282 | MCOUNT_EXIT; |
| 283 | #endif |
| 284 | return; |
| 285 | } |
| 286 | #endif |
| 287 | |
| 288 | #ifdef MCOUNT |
| 289 | /* |
| 290 | * Actual definition of mcount function. Defined in <machine/profile.h>, |
| 291 | * which is included by <sys/gmon.h>. |
| 292 | */ |
| 293 | MCOUNT |
| 294 | #endif |
| 295 | |
| 296 | #endif /* (!_KERNEL || GPROF) && !_STANDALONE */ |
| 297 | |