Hi! Patch looks, sounds and runs good; similar (correct) code is already in
char **Dbg_ArgcArgv(argc,argv,copy) ... main_argv = alloc = (char **)ckalloc((argc+1)*sizeof(char *)); >From my initial tests, this has corrected a nasty segmentation fault that occurred sometimes inside the debugger. If you don't already know, I have a modification to enable debugging inside the TKCon console http://tagus.inesc-id.pt/~pestrela/ns2/ns2_debugging2.html I'm forwarding this patch to the ns-developers list Pedro Vale Estrela > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf > Of Christian Walter > Sent: terça-feira, 5 de Setembro de 2006 17:35 > To: ns-users@ISI.EDU > Subject: [ns] [bug] tcl-debugger segfaults when printing stack ('w') > > > [Bug Report] > > ----------------------------- > Category: Run Time - Segmentation Fault > Package: other tcl-debug-2.0 > OS: RHEL4/OTHERS > Environment Variables: > > > ----------------------------- > Description: > > Description of Problem: > > The tcl debugger tcl-debug 2.0 from Don Libes contains a bug in the > function print_objc (Dbg.c:445) where not enough memory is allocated. The > variable argv[] should hold an array of char * pointers. The call to > malloc misses parentheses around objc + 1 and allocates insufficient > memory. > A recent GLIBC as well as valgrind detect the error and aborts program > execution. As a consequence the simulator execution is aborted by the > system environment. > > How Easily Reproducible: every time > > Steps to Reproduce: > 1. Start ns2 > 2. Enter 'debug 1' > 3. Hit s until the stack has at least two elements. starting ns and using > 's' three or more time is sufficient. > 3. Simply execute some commands where you should use 'w' multiple times. > valgrind will immediately detect it. glibc runtime checks sometimes. > > Requirements: > Ns compiled with --with-debug and tcl-debug. In addition the following > system components/libraries are of interest: > > Linux: CentOS release 4.4 > GLIBC: glibc-2.3.4-2.25 > valgrind: valgrind-3.1.1-1.EL4 > > Actual Results: > > GLIBC: > dbg2.7> w > 0: application > *1: history {add} {s > } > 2: llength {add {s > }} > dbg2.8> w > *** glibc detected *** malloc(): memory corruption (fast): 0x08629bf8 *** > Aborted > > VALGRIND: > > dbg2.6> s > 2: set len [llength $args] > dbg2.7> w > 0: application > ==12203== Invalid write of size 4 > ==12203== at 0x8242DFB: print_objv (Dbg.c:445) > ==12203== by 0x8242EB5: PrintStackBelow (Dbg.c:469) > ==12203== by 0x8242EED: PrintStack (Dbg.c:488) > ==12203== by 0x82432E5: debugger_trap (Dbg.c:696) > > Expected Results: > No output > > Additional Information: > Patch is supplied below: > --- Dbg.c.orig 2000-08-16 00:09:30.000000000 +0200 > +++ Dbg.c 2006-09-05 17:05:43.000000000 +0200 > @@ -440,7 +440,7 @@ > char **argv; > int argc; > int len; > - argv = (char **)ckalloc(objc+1 * sizeof(char *)); > + argv = (char **)ckalloc((objc + 1) * sizeof(char *)); > for (argc=0 ; argc<objc ; argc++) { > argv[argc] = Tcl_GetStringFromObj(objv[argc],&len); > } > > Kind regards, > Christian Walter
