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 */
  35
  36 #include "native/jvmti/cacaodbgserver.h"
  37 #include "native/jvmti/cacaodbg.h"
  38 #include "native/jvmti/dbg.h"
  39 #include <sys/types.h>
  40 #include <unistd.h>
  41 #include <signal.h>
  42 #include <sys/wait.h>
  43 #include <stdlib.h>
  44 #include <stdio.h>
  45 #include <assert.h>
  46 #include <string.h>
  47
  48 FILE *gdbin, *gdbout; /* file descriptor for gdb pipes */
  49
  50 struct _pending_brkpt {
  51         int brknumber;
  52         unsigned long threadid;
  53         char* regs;
  54 };
  55
  56 struct _pending_brkpt *pending_brkpts;
  57 int pending_brkpts_size;
  58
  59
  60 static void closepipeend (int fd) {
  61         if (close(fd) == -1) {
  62                 perror("unable to close pipe - ");
  63                 exit(1);
  64         }
  65 }
  66
  67 /* startgdb *******************************************************************
  68
  69    starts a gdb session and creates two pipes connection gdb stdout/stdin to
  70    gdbin/gdbout
  71
  72 *******************************************************************************/
  73
  74 static void startgdb() {
  75         char gdbargs[20];
  76         int cacao2gdbpipe[2],gdb2cacaopipe[2];
  77
  78         pipe(cacao2gdbpipe);
  79         pipe(gdb2cacaopipe);
  80
  81         snprintf(gdbargs,20,"--pid=%d",getppid());
  82
  83         switch(fork()) {
  84         case -1:
  85                 fprintf(stderr,"cacaodbgserver: fork error\n");
  86                 exit(1);
  87         case 0:
  88                 /* child */
  89                 closepipeend(gdb2cacaopipe[0]); /* read end */
  90                 closepipeend(cacao2gdbpipe[1]); /* write end */
  91
  92                 /* connect stdin of gdb to cacao2gdbpipe */
  93                 dup2(cacao2gdbpipe[0],0);
  94                 /* connect stdout of gdb to gdb2cacaopipe */
  95                 dup2(gdb2cacaopipe[1],1);
  96
  97                 if (execlp("gdb","gdb","--interpreter=mi" ,gdbargs,(char *) NULL)==-1){
  98                         fprintf(stderr,"cacaodbgserver: unable to start gdb\n");
  99                         exit(1);
 100                 }
 101         default:
 102                 /* parent */
 103                 closepipeend(gdb2cacaopipe[1]); /* write end */
 104                 closepipeend(cacao2gdbpipe[0]); /* read end */
 105
 106                 gdbin = fdopen(gdb2cacaopipe[0],"r");
 107                 gdbout = fdopen(cacao2gdbpipe[1],"w");
 108         }
 109
 110 }
 111
 112
 113 #define SENDCMD(CMD) \
 114         fprintf(gdbout,"%s",CMD); \
 115         fflush(gdbout); \
 116
 117
 118 static void getgdboutput(char *inbuf,int buflen) {
 119         int i=0;
 120         inbuf[0]='\0';
 121         do {
 122                 i += strlen(&inbuf[i]);
 123                 if (fgets(&inbuf[i],buflen-i,gdbin)==NULL) {
 124                         perror("cacaodbgserver: ");
 125                         exit(1);
 126                 }
 127         } while(!(strncmp(OUTPUTEND,&inbuf[i],OUTPUTENDSIZE)==0));
 128 }
 129
 130
 131 /* dataevaluate ***************************************************************
 132
 133    evaluates expr returning long in gdb and returns the result
 134
 135 *******************************************************************************/
 136
 137 static unsigned long dataevaluate(char *expr) {
 138         char *match, inbuf[160];
 139
 140         fprintf(gdbout,"-data-evaluate-expression %s\n",expr);
 141         fflush(gdbout);
 142
 143         getgdboutput(inbuf,160);
 144         if ((match=strstr(inbuf,DATAEVALUATE)) == NULL) {
 145                 fprintf(stderr,"dataevaluate: no matching value\n");
 146                 return -1;
 147         }
 148         return strtoll(&match[strlen(DATAEVALUATE)], NULL, 16);
 149 }
 150
 151
 152 /* commonbreakpointhandler *****************************************************
 153
 154    called by gdb and hard coded breakpoint handler
 155
 156 *******************************************************************************/
 157
 158 static bool commonbreakpointhandler(char* sigbuf, int sigtrap) {
 159         int numberofbreakpoints, i;
 160         char tmp[INBUFLEN], *match;
 161         unsigned long addr;
 162
 163         if ((match=strstr(sigbuf,SIGADDR))==NULL) {
 164                 fprintf(stderr,"commonbreakpointhandler: no matching address(%s)\n",
 165                                 sigbuf);
 166                 return true;
 167         }
 168
 169         addr = strtoll(&match[strlen(SIGADDR)],NULL,16);
 170         if (sigtrap) addr--;
 171
 172
 173         numberofbreakpoints = (int)dataevaluate("dbgcom->jvmtibrkpt.num");
 174
 175         i = -1;
 176         do {
 177                 i++;
 178                 snprintf(tmp,INBUFLEN,"dbgcom->jvmtibrkpt.brk[%d].addr",i);
 179         } while ((i<numberofbreakpoints) && (dataevaluate(tmp) != addr));
 180
 181         assert(i<numberofbreakpoints);
 182
 183         /* handle system breakpoints */
 184         switch(i) {
 185         case SETSYSBRKPT:
 186                 /* add a breakpoint */
 187                 fprintf(gdbout,"break *0x%lx\n",dataevaluate("dbgcom->brkaddr"));
 188                 fflush(gdbout);
 189                 getgdboutput(tmp,INBUFLEN);
 190                 break;
 191         case CACAODBGSERVERQUIT:
 192                 SENDCMD("-gdb-exit\n");
 193                 return false;
 194         default:
 195                 /* other breakpoints -> call jvmti_cacao_generic_breakpointhandler
 196                    in the cacao vm */
 197                 fprintf(gdbout,"call jvmti_cacao_generic_breakpointhandler(%d)\n",i);
 198                 fflush(gdbout);
 199                 getgdboutput(tmp,INBUFLEN);
 200         }
 201         SENDCMD(CONTINUE);
 202         getgdboutput(tmp,INBUFLEN);
 203         return true;
 204 }
 205
 206 /* controlloop ****************************************************************
 207
 208    this function controls the gdb behaviour
 209
 210 *******************************************************************************/
 211
 212 static void controlloop() {
 213         char inbuf[INBUFLEN], *match;
 214         bool running = true;
 215
 216         pending_brkpts_size = 5;
 217         pending_brkpts = malloc(sizeof(struct _pending_brkpt)*pending_brkpts_size);
 218
 219         getgdboutput(inbuf,INBUFLEN);   /* read gdb welcome message */
 220
 221         SENDCMD("handle SIGSEGV SIGPWR SIGXCPU SIGBUS noprint nostop\n");
 222         getgdboutput(inbuf,INBUFLEN);
 223
 224         SENDCMD("print dbgcom\n");
 225         getgdboutput(inbuf,INBUFLEN);
 226
 227         SENDCMD(CONTINUE);
 228         getgdboutput(inbuf,INBUFLEN);
 229
 230         while(running) {
 231                 getgdboutput(inbuf,INBUFLEN);
 232
 233                 if ((match=strstr(inbuf,HCSIGTRAP))!=NULL) {
 234                         running = commonbreakpointhandler(match,1);
 235                         continue;
 236                         }
 237
 238                 if ((match=strstr(inbuf,GDBBREAKPOINT))!=NULL) {
 239                         running = commonbreakpointhandler(match,0);
 240                         continue;
 241                 }
 242
 243                 if (strstr(inbuf,EXITEDNORMALLY) != NULL) {
 244                         /* quit gdb */
 245                         SENDCMD ("-gdb-exit");
 246                         running = false;
 247                         continue;
 248                 }
 249
 250                 if ((inbuf[0]!=LOGSTREAMOUTPUT) && (inbuf[0]!=CONSOLESTREAMOUTPUT)) {
 251                         fprintf(stderr,"gdbin not handled %s\n",inbuf);
 252                         fprintf(gdbout,"bt\n");
 253                         fflush(gdbout);
 254                         fprintf(stderr,"not handled 1\n");
 255                         fflush(stderr);
 256                         getgdboutput(inbuf,INBUFLEN);
 257                         fprintf(stderr,"gdbin: %s\n",inbuf);
 258                         SENDCMD("-gdb-exit\n");
 259                         return;
 260                 }
 261         }
 262
 263         free(pending_brkpts);
 264 }
 265
 266 /* main (cacaodbgserver) ******************************************************
 267
 268    main function for cacaodbgserver process.
 269
 270 *******************************************************************************/
 271
 272 int main(int argc, char **argv) {
 273         startgdb();
 274
 275         controlloop();
 276
 277         return 0;
 278 }
 279
 280
 281 /*
 282  * These are local overrides for various environment variables in Emacs.
 283  * Please do not remove this and leave it at the end of the file, where
 284  * Emacs will automagically detect them.
 285  * ---------------------------------------------------------------------
 286  * Local variables:
 287  * mode: c
 288  * indent-tabs-mode: t
 289  * c-basic-offset: 4
 290  * tab-width: 4
 291  * End:
 292  * vim:noexpandtab:sw=4:ts=4:
 293  */