libgloss/i386/cygmon-gmon.c

   1 /*-
   2  * Copyright (c) 1991, 2000 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * This is a modified gmon.c by J.W.Hawtin <oolon@ankh.org>,
  32  * 14/8/96 based on the original gmon.c in GCC and the hacked version
  33  * solaris 2 sparc version (config/sparc/gmon-sol.c) by Mark Eichin. To do
  34  * process profiling on solaris 2.X X86
  35  *
  36  * It must be used in conjunction with sol2-gc1.asm, which is used to start
  37  * and stop process monitoring.
  38  *
  39  * Differences.
  40  *
  41  * On Solaris 2 _mcount is called by library functions not mcount, so support
  42  * has been added for both.
  43  *
  44  * Also the prototype for profil() is different
  45  *
  46  * Solaris 2 does not seem to have char *minbrk which allows the setting of
  47  * the minimum SBRK region so this code has been removed and lets pray malloc
  48  * does not mess it up.
  49  *
  50  * Notes
  51  *
  52  * This code could easily be integrated with the original gmon.c and perhaps
  53  * should be.
  54  */
  55
  56 #ifndef lint
  57 static char sccsid[] = "@(#)gmon.c      5.3 (Berkeley) 5/22/91";
  58 #endif /* not lint */
  59
  60 #define DEBUG
  61 #ifdef DEBUG
  62 #include <stdio.h>
  63 #endif
  64
  65 #include "cygmon-gmon.h"
  66
  67 /*
  68  *      froms is actually a bunch of unsigned shorts indexing tos
  69  */
  70 static int              profiling = 3;
  71 static unsigned short   *froms;
  72 static struct tostruct  *tos = 0;
  73 static long             tolimit = 0;
  74 static char             *s_lowpc = 0;
  75 static char             *s_highpc = 0;
  76 static unsigned long    s_textsize = 0;
  77
  78 static int      ssiz;
  79 static char     *sbuf;
  80 static int      s_scale;
  81     /* see profil(2) where this is describe (incorrectly) */
  82 #define         SCALE_1_TO_1    0x10000L
  83
  84 #define MSG "No space for profiling buffer(s)\n"
  85
  86 extern int errno;
  87
  88 int
  89 monstartup(lowpc, highpc)
  90      char       *lowpc;
  91      char       *highpc;
  92 {
  93   int           monsize;
  94   char          *buffer;
  95   register int  o;
  96
  97         /*
  98          *      round lowpc and highpc to multiples of the density we're using
  99          *      so the rest of the scaling (here and in gprof) stays in ints.
 100          */
 101   lowpc = (char *)
 102     ROUNDDOWN((unsigned)lowpc, HISTFRACTION*sizeof(HISTCOUNTER));
 103   s_lowpc = lowpc;
 104   highpc = (char *)
 105     ROUNDUP((unsigned)highpc, HISTFRACTION*sizeof(HISTCOUNTER));
 106   s_highpc = highpc;
 107   s_textsize = highpc - lowpc;
 108   monsize = (s_textsize / HISTFRACTION) + sizeof(struct phdr);
 109   buffer = (char *) sbrk (monsize);
 110   if (buffer == (char *) -1)
 111     {
 112       write (2, MSG , sizeof(MSG));
 113       return;
 114     }
 115   bzero (buffer, monsize);
 116   froms = (unsigned short *) sbrk (s_textsize / HASHFRACTION);
 117   if (froms == (unsigned short *) -1)
 118     {
 119       write(2, MSG, sizeof(MSG));
 120       froms = 0;
 121       return;
 122     }
 123   bzero (froms, s_textsize / HASHFRACTION);
 124   tolimit = s_textsize * ARCDENSITY / 100;
 125   if (tolimit < MINARCS)
 126     {
 127       tolimit = MINARCS;
 128     }
 129   else
 130     {
 131       if (tolimit > 65534)
 132         {
 133           tolimit = 65534;
 134         }
 135     }
 136   tos = (struct tostruct *) sbrk( tolimit * sizeof( struct tostruct ) );
 137   if (tos == (struct tostruct *) -1)
 138     {
 139       write (2, MSG, sizeof(MSG));
 140       froms = 0;
 141       tos = 0;
 142       return;
 143     }
 144   bzero (tos, tolimit * sizeof( struct tostruct ) );
 145   tos[0].link = 0;
 146   sbuf = buffer;
 147   ssiz = monsize;
 148   ( (struct phdr *) buffer ) -> lpc = lowpc;
 149   ( (struct phdr *) buffer ) -> hpc = highpc;
 150   ( (struct phdr *) buffer ) -> ncnt = ssiz;
 151   monsize -= sizeof(struct phdr);
 152   if ( monsize <= 0 )
 153     return;
 154   o = highpc - lowpc;
 155   if (monsize < o)
 156     {
 157         s_scale = ( (float) monsize / o ) * SCALE_1_TO_1;
 158     }
 159   else
 160     s_scale = SCALE_1_TO_1;
 161   moncontrol (1);
 162 }
 163
 164 void
 165 _mcleanup()
 166 {
 167   int           fd;
 168   int           fromindex;
 169   int           endfrom;
 170   char          *frompc;
 171   int           toindex;
 172   struct rawarc rawarc;
 173
 174   moncontrol (0);
 175   profil_write (1, sbuf, ssiz);
 176
 177   endfrom = s_textsize / (HASHFRACTION * sizeof(*froms));
 178   for ( fromindex = 0 ; fromindex < endfrom ; fromindex++ )
 179     {
 180       if ( froms[fromindex] == 0 )
 181         {
 182           continue;
 183         }
 184       frompc = s_lowpc + (fromindex * HASHFRACTION * sizeof(*froms));
 185       for (toindex=froms[fromindex]; toindex!=0; toindex=tos[toindex].link)
 186         {
 187           rawarc.raw_frompc = (unsigned long) frompc;
 188           rawarc.raw_selfpc = (unsigned long) tos[toindex].selfpc;
 189           rawarc.raw_count = tos[toindex].count;
 190           profil_write (2, &rawarc, sizeof (rawarc));
 191         }
 192     }
 193   profil_write (3, 0, 0);
 194 }
 195
 196 static char already_setup = 0;
 197
 198 _mcount()
 199 {
 200   register char                 *selfpc;
 201   register unsigned short       *frompcindex;
 202   register struct tostruct      *top;
 203   register struct tostruct      *prevtop;
 204   register long                 toindex;
 205
 206   /*
 207    *    find the return address for mcount,
 208    *    and the return address for mcount's caller.
 209    */
 210
 211   /* selfpc = pc pushed by mcount call.
 212      This identifies the function that was just entered.  */
 213   selfpc = (void *) __builtin_return_address (0);
 214   /* frompcindex = pc in preceding frame.
 215      This identifies the caller of the function just entered.  */
 216   frompcindex = (void *) __builtin_return_address (1);
 217
 218   if (! already_setup)
 219     {
 220       extern _etext();
 221       extern _ftext();
 222       already_setup = 1;
 223       monstartup(_ftext, _etext);
 224       atexit(_mcleanup);
 225     }
 226   /*
 227    *    check that we are profiling
 228    *    and that we aren't recursively invoked.
 229    */
 230   if (profiling)
 231     {
 232       goto out;
 233     }
 234   profiling++;
 235   /*
 236    *    check that frompcindex is a reasonable pc value.
 237    *    for example:    signal catchers get called from the stack,
 238    *                    not from text space.  too bad.
 239    */
 240   frompcindex = (unsigned short *)((long)frompcindex - (long)s_lowpc);
 241   if ((unsigned long)frompcindex > s_textsize)
 242     {
 243       goto done;
 244     }
 245   frompcindex =
 246     &froms[((long)frompcindex) / (HASHFRACTION * sizeof(*froms))];
 247   toindex = *frompcindex;
 248   if (toindex == 0)
 249     {
 250       /*
 251        *        first time traversing this arc
 252        */
 253       toindex = ++tos[0].link;
 254       if (toindex >= tolimit)
 255         {
 256           goto overflow;
 257         }
 258       *frompcindex = toindex;
 259       top = &tos[toindex];
 260       top->selfpc = selfpc;
 261       top->count = 1;
 262       top->link = 0;
 263       goto done;
 264     }
 265   top = &tos[toindex];
 266   if (top->selfpc == selfpc)
 267     {
 268       /*
 269        *        arc at front of chain; usual case.
 270        */
 271       top->count++;
 272       goto done;
 273     }
 274   /*
 275    *    have to go looking down chain for it.
 276    *    top points to what we are looking at,
 277    *    prevtop points to previous top.
 278    *    we know it is not at the head of the chain.
 279    */
 280   for (; /* goto done */; )
 281     {
 282       if (top->link == 0)
 283         {
 284           /*
 285            *    top is end of the chain and none of the chain
 286            *    had top->selfpc == selfpc.
 287            *    so we allocate a new tostruct
 288            *    and link it to the head of the chain.
 289            */
 290           toindex = ++tos[0].link;
 291           if (toindex >= tolimit)
 292             {
 293               goto overflow;
 294             }
 295           top = &tos[toindex];
 296           top->selfpc = selfpc;
 297           top->count = 1;
 298           top->link = *frompcindex;
 299           *frompcindex = toindex;
 300           goto done;
 301         }
 302       /*
 303        *        otherwise, check the next arc on the chain.
 304        */
 305       prevtop = top;
 306       top = &tos[top->link];
 307       if (top->selfpc == selfpc)
 308         {
 309           /*
 310            *    there it is.
 311            *    increment its count
 312            *    move it to the head of the chain.
 313            */
 314           top->count++;
 315           toindex = prevtop->link;
 316           prevtop->link = top->link;
 317           top->link = *frompcindex;
 318           *frompcindex = toindex;
 319           goto done;
 320         }
 321     }
 322 done:
 323   profiling--;
 324   /* and fall through */
 325 out:
 326   return;               /* normal return restores saved registers */
 327
 328 overflow:
 329   profiling++; /* halt further profiling */
 330 #   define      TOLIMIT "mcount: tos overflow\n"
 331   write (2, TOLIMIT, sizeof(TOLIMIT));
 332   goto out;
 333 }
 334
 335 /*
 336  * Control profiling
 337  *      profiling is what mcount checks to see if
 338  *      all the data structures are ready.
 339  */
 340 moncontrol(mode)
 341     int mode;
 342 {
 343   if (mode)
 344     {
 345       /* start */
 346       profil((unsigned short *)(sbuf + sizeof(struct phdr)),
 347              ssiz - sizeof(struct phdr),
 348              (int)s_lowpc, s_scale);
 349
 350       profiling = 0;
 351     }
 352   else
 353     {
 354       /* stop */
 355       profil((unsigned short *)0, 0, 0, 0);
 356       profiling = 3;
 357     }
 358 }