src/native/jvmti/cacaodbgserver.c

   1
   2 /* src/native/jvmti/cacaodbgserver.c - contains the cacaodbgserver process. This
   3                                        process controls the cacao vm through gdb
   4
   5    Copyright (C) 1996-2005, 2006 R. Grafl, A. Krall, C. Kruegel,
   6    C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
   7    E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
   8    J. Wenninger, Institut f. Computersprachen - TU Wien
   9
  10    This file is part of CACAO.
  11
  12    This program is free software; you can redistribute it and/or
  13    modify it under the terms of the GNU General Public License as
  14    published by the Free Software Foundation; either version 2, or (at
  15    your option) any later version.
  16
  17    This program is distributed in the hope that it will be useful, but
  18    WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20    General Public License for more details.
  21
  22    You should have received a copy of the GNU General Public License
  23    along with this program; if not, write to the Free Software
  24    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  25    02111-1307, USA.
  26
  27    Contact: cacao@complang.tuwien.ac.at
  28
  29    Authors: Martin Platter
  30
  31    Changes: Edwin Steiner
  32             Samuel Vinson
  33
  34    $Id: cacaodbgserver.c $
  35
  36 */
  37
  38 #include "native/jvmti/cacaodbgserver.h"
  39 #include "native/jvmti/cacaodbg.h"
  40 #include "native/jvmti/dbg.h"
  41 #include <sys/types.h>
  42 #include <unistd.h>
  43 #include <signal.h>
  44 #include <sys/wait.h>
  45 #include <stdlib.h>
  46 #include <stdio.h>
  47 #include <assert.h>
  48 #include <string.h>
  49
  50 FILE *gdbin, *gdbout; /* file descriptor for gdb pipes */
  51
  52 struct _pending_brkpt {
  53         int brknumber;
  54         unsigned long threadid;
  55         char* regs;
  56 };
  57
  58 struct _pending_brkpt *pending_brkpts;
  59 int pending_brkpts_size;
  60
  61
  62 static void closepipeend (int fd) {
  63         if (close(fd) == -1) {
  64                 perror("unable to close pipe - ");
  65                 exit(1);
  66         }
  67 }
  68
  69 /* startgdb *******************************************************************
  70
  71    starts a gdb session and creates two pipes connection gdb stdout/stdin to
  72    gdbin/gdbout
  73
  74 *******************************************************************************/
  75
  76 static void startgdb() {
  77         char gdbargs[20];
  78         int cacao2gdbpipe[2],gdb2cacaopipe[2];
  79
  80         pipe(cacao2gdbpipe);
  81         pipe(gdb2cacaopipe);
  82
  83         snprintf(gdbargs,20,"--pid=%d",getppid());
  84
  85         switch(fork()) {
  86         case -1:
  87                 fprintf(stderr,"cacaodbgserver: fork error\n");
  88                 exit(1);
  89         case 0:
  90                 /* child */
  91                 closepipeend(gdb2cacaopipe[0]); /* read end */
  92                 closepipeend(cacao2gdbpipe[1]); /* write end */
  93
  94                 /* connect stdin of gdb to cacao2gdbpipe */
  95                 dup2(cacao2gdbpipe[0],0);
  96                 /* connect stdout of gdb to gdb2cacaopipe */
  97                 dup2(gdb2cacaopipe[1],1);
  98
  99                 if (execlp("gdb","gdb","--interpreter=mi" ,gdbargs,(char *) NULL)==-1){
 100                         fprintf(stderr,"cacaodbgserver: unable to start gdb\n");
 101                         exit(1);
 102                 }
 103         default:
 104                 /* parent */
 105                 closepipeend(gdb2cacaopipe[1]); /* write end */
 106                 closepipeend(cacao2gdbpipe[0]); /* read end */
 107
 108                 gdbin = fdopen(gdb2cacaopipe[0],"r");
 109                 gdbout = fdopen(cacao2gdbpipe[1],"w");
 110         }
 111
 112 }
 113
 114
 115 #define SENDCMD(CMD) \
 116         fprintf(gdbout,"%s",CMD); \
 117         fflush(gdbout); \
 118
 119
 120 static void getgdboutput(char *inbuf,int buflen) {
 121         int i=0;
 122         inbuf[0]='\0';
 123         do {
 124                 i += strlen(&inbuf[i]);
 125                 if (fgets(&inbuf[i],buflen-i,gdbin)==NULL) {
 126                         perror("cacaodbgserver: ");
 127                         exit(1);
 128                 }
 129         } while(!(strncmp(OUTPUTEND,&inbuf[i],OUTPUTENDSIZE)==0));
 130 }
 131
 132
 133 /* dataevaluate ***************************************************************
 134
 135    evaluates expr returning long in gdb and returns the result
 136
 137 *******************************************************************************/
 138
 139 static unsigned long dataevaluate(char *expr) {
 140         char *match, inbuf[160];
 141
 142         fprintf(gdbout,"-data-evaluate-expression %s\n",expr);
 143         fflush(gdbout);
 144
 145         getgdboutput(inbuf,160);
 146         if ((match=strstr(inbuf,DATAEVALUATE)) == NULL) {
 147                 fprintf(stderr,"dataevaluate: no matching value\n");
 148                 return -1;
 149         }
 150         return strtoll(&match[strlen(DATAEVALUATE)], NULL, 16);
 151 }
 152
 153
 154 /* commonbreakpointhandler *****************************************************
 155
 156    called by gdb and hard coded breakpoint handler
 157
 158 *******************************************************************************/
 159
 160 static bool commonbreakpointhandler(char* sigbuf, int sigtrap) {
 161         int numberofbreakpoints, i;
 162         char tmp[INBUFLEN], *match;
 163         unsigned long addr;
 164
 165         if ((match=strstr(sigbuf,SIGADDR))==NULL) {
 166                 fprintf(stderr,"commonbreakpointhandler: no matching address(%s)\n",
 167                                 sigbuf);
 168                 return true;
 169         }
 170
 171         addr = strtoll(&match[strlen(SIGADDR)],NULL,16);
 172         if (sigtrap) addr--;
 173
 174
 175         numberofbreakpoints = (int)dataevaluate("dbgcom->jvmtibrkpt.num");
 176
 177         i = -1;
 178         do {
 179                 i++;
 180                 snprintf(tmp,INBUFLEN,"dbgcom->jvmtibrkpt.brk[%d].addr",i);
 181         } while ((i<numberofbreakpoints) && (dataevaluate(tmp) != addr));
 182
 183         assert(i<numberofbreakpoints);
 184
 185         /* handle system breakpoints */
 186         switch(i) {
 187         case SETSYSBRKPT:
 188                 /* add a breakpoint */
 189                 fprintf(gdbout,"break *0x%lx\n",dataevaluate("dbgcom->brkaddr"));
 190                 fflush(gdbout);
 191                 getgdboutput(tmp,INBUFLEN);
 192                 break;
 193         case CACAODBGSERVERQUIT:
 194                 SENDCMD("-gdb-exit\n");
 195                 return false;
 196         default:
 197                 /* other breakpoints -> call jvmti_cacao_generic_breakpointhandler
 198                    in the cacao vm */
 199                 fprintf(gdbout,"call jvmti_cacao_generic_breakpointhandler(%d)\n",i);
 200                 fflush(gdbout);
 201                 getgdboutput(tmp,INBUFLEN);
 202         }
 203         SENDCMD(CONTINUE);
 204         getgdboutput(tmp,INBUFLEN);
 205         return true;
 206 }
 207
 208 /* controlloop ****************************************************************
 209
 210    this function controls the gdb behaviour
 211
 212 *******************************************************************************/
 213
 214 static void controlloop() {
 215         char inbuf[INBUFLEN], *match;
 216         bool running = true;
 217
 218         pending_brkpts_size = 5;
 219         pending_brkpts = malloc(sizeof(struct _pending_brkpt)*pending_brkpts_size);
 220
 221         getgdboutput(inbuf,INBUFLEN);   /* read gdb welcome message */
 222
 223         SENDCMD("handle SIGSEGV SIGPWR SIGXCPU SIGBUS noprint nostop\n");
 224         getgdboutput(inbuf,INBUFLEN);
 225
 226         SENDCMD("print dbgcom\n");
 227         getgdboutput(inbuf,INBUFLEN);
 228
 229         SENDCMD(CONTINUE);
 230         getgdboutput(inbuf,INBUFLEN);
 231
 232         while(running) {
 233                 getgdboutput(inbuf,INBUFLEN);
 234
 235                 if ((match=strstr(inbuf,HCSIGTRAP))!=NULL) {
 236                         running = commonbreakpointhandler(match,1);
 237                         continue;
 238                         }
 239
 240                 if ((match=strstr(inbuf,GDBBREAKPOINT))!=NULL) {
 241                         running = commonbreakpointhandler(match,0);
 242                         continue;
 243                 }
 244
 245                 if (strstr(inbuf,EXITEDNORMALLY) != NULL) {
 246                         /* quit gdb */
 247                         SENDCMD ("-gdb-exit");
 248                         running = false;
 249                         continue;
 250                 }
 251
 252                 if ((inbuf[0]!=LOGSTREAMOUTPUT) && (inbuf[0]!=CONSOLESTREAMOUTPUT)) {
 253                         fprintf(stderr,"gdbin not handled %s\n",inbuf);
 254                         fprintf(gdbout,"bt\n");
 255                         fflush(gdbout);
 256                         fprintf(stderr,"not handled 1\n");
 257                         fflush(stderr);
 258                         getgdboutput(inbuf,INBUFLEN);
 259                         fprintf(stderr,"gdbin: %s\n",inbuf);
 260                         SENDCMD("-gdb-exit\n");
 261                         return;
 262                 }
 263         }
 264
 265         free(pending_brkpts);
 266 }
 267
 268 /* main (cacaodbgserver) ******************************************************
 269
 270    main function for cacaodbgserver process.
 271
 272 *******************************************************************************/
 273
 274 int main(int argc, char **argv) {
 275         startgdb();
 276
 277         controlloop();
 278
 279         return 0;
 280 }
 281
 282
 283 /*
 284  * These are local overrides for various environment variables in Emacs.
 285  * Please do not remove this and leave it at the end of the file, where
 286  * Emacs will automagically detect them.
 287  * ---------------------------------------------------------------------
 288  * Local variables:
 289  * mode: c
 290  * indent-tabs-mode: t
 291  * c-basic-offset: 4
 292  * tab-width: 4
 293  * End:
 294  * vim:noexpandtab:sw=4:ts=4:
 295  */