2000-10-23 Fernando Nasser <fnasser@redhat.com>

	From 2000-10-19  Steven Johnson  <sbjohnson@ozemail.com.au>
        Note: The original patch used asprintf/vasprintf.  I changed it to
	use the new xasprintf/xvasprintf gdb functions.
        * gdbtk.c (TclDebug, gdbtk_init): Replaced the vast majority of
	sprintf/vsprintf calls with asprintf and vasprintf respectively.
	Should prevent any possible buffer overruns possible with
	fixed size sprintf buffers. Specifically fixes a problem with long
	filenames and clearing breakpoints overflowing their buffers when
	using sprintf, causing a segfault. Generically should also prevent
	any other similar problems from occuring.
        * gdbtk-cmds.c (sprintf_append_element_to_obj, get_pc_register,
	gdb_get_tracepoint_info, gdb_load_disassembly, gdbtk_load_source,
	gdbtk_load_asm, gdb_set_bp, gdb_set_bp_addr, gdb_get_breakpoint_info,
	gdb_selected_frame, gdb_selected_block, gdb_get_blocks): Ditto.
        * gdbtk-hooks.c (gdbtk_warning, gdbtk_ignorable_warning,
	gdbtk_readline_begin, gdbtk_set_hook, breakpoint_notify,
	gdbtk_query, tracepoint_notify, gdbtk_error_begin,
	gdbtk_annotate_signal): Ditto.

diff --git a/gdb/gdbtk/generic/ChangeLog b/gdb/gdbtk/generic/ChangeLog
index 4a8c538..d3c48a1 100644 (file)
--- a/gdb/gdbtk/generic/ChangeLog
+++ b/gdb/gdbtk/generic/ChangeLog
@@ -1,3 +1,24 @@
+2000-10-23  Fernando Nasser  <fnasser@redhat.com>
+
+       From 2000-10-19  Steven Johnson  <sbjohnson@ozemail.com.au>
+        Note: The original patch used asprintf/vasprintf.  I changed it to
+       use the new xasprintf/xvasprintf gdb functions.
+        * gdbtk.c (TclDebug, gdbtk_init): Replaced the vast majority of
+       sprintf/vsprintf calls with asprintf and vasprintf respectively.
+       Should prevent any possible buffer overruns possible with
+       fixed size sprintf buffers. Specifically fixes a problem with long
+       filenames and clearing breakpoints overflowing their buffers when
+       using sprintf, causing a segfault. Generically should also prevent
+       any other similar problems from occuring.
+        * gdbtk-cmds.c (sprintf_append_element_to_obj, get_pc_register,
+       gdb_get_tracepoint_info, gdb_load_disassembly, gdbtk_load_source,
+       gdbtk_load_asm, gdb_set_bp, gdb_set_bp_addr, gdb_get_breakpoint_info,
+       gdb_selected_frame, gdb_selected_block, gdb_get_blocks): Ditto.
+        * gdbtk-hooks.c (gdbtk_warning, gdbtk_ignorable_warning,
+       gdbtk_readline_begin, gdbtk_set_hook, breakpoint_notify,
+       gdbtk_query, tracepoint_notify, gdbtk_error_begin,
+       gdbtk_annotate_signal): Ditto.
+
 2000-10-23  Fernando Nasser  <fnasser@totem.to.cygnus.com>
 
        * gdbtk-hooks.c (x_event): Only process events if the target is

diff --git a/gdb/gdbtk/generic/gdbtk-cmds.c b/gdb/gdbtk/generic/gdbtk-cmds.c
index f11f631..c1535d4 100644 (file)
--- a/gdb/gdbtk/generic/gdbtk-cmds.c
+++ b/gdb/gdbtk/generic/gdbtk-cmds.c
@@ -545,13 +545,14 @@ static void
 sprintf_append_element_to_obj (Tcl_Obj * objp, char *format,...)
 {
   va_list args;
-  char buf[1024];
+  char *buf;
 
   va_start (args, format);
 
-  vsprintf (buf, format, args);
+  xvasprintf (&buf, format, args);
 
   Tcl_ListObjAppendElement (NULL, objp, Tcl_NewStringObj (buf, -1));
+  free(buf);
 }
 \f
 /*
@@ -2008,10 +2009,11 @@ get_pc_register (clientData, interp, objc, objv)
      int objc;
      Tcl_Obj *CONST objv[];
 {
-  char buff[64];
+  char *buff;
 
-  sprintf (buff, "0x%llx", (long long) read_register (PC_REGNUM));
+  xasprintf (&buff, "0x%llx", (long long) read_register (PC_REGNUM));
   Tcl_SetStringObj (result_ptr->obj_ptr, buff, -1);
+  free(buff);
   return TCL_OK;
 }
 
@@ -2180,9 +2182,10 @@ gdb_get_tracepoint_info (clientData, interp, objc, objv)
 
   if (tp == NULL)
     {
-      char buff[64];
-      sprintf (buff, "Tracepoint #%d does not exist", tpnum);
+      char *buff;
+      xasprintf (&buff, "Tracepoint #%d does not exist", tpnum);
       Tcl_SetStringObj (result_ptr->obj_ptr, buff, -1);
+      free(buff);
       return TCL_ERROR;
     }
 
@@ -2202,7 +2205,7 @@ gdb_get_tracepoint_info (clientData, interp, objc, objv)
                            Tcl_NewIntObj (sal.line));
   {
     char *tmp;
-    asprintf (&tmp, "0x%s", paddr_nz (tp->address));
+    xasprintf (&tmp, "0x%s", paddr_nz (tp->address));
     Tcl_ListObjAppendElement (interp, result_ptr->obj_ptr,
                              Tcl_NewStringObj (tmp, -1));
     free (tmp);
@@ -2597,14 +2600,16 @@ gdb_load_disassembly (clientData, interp, objc, objv)
      into the Tcl result. */
 
   if (ret_val == TCL_OK) {
-    char buffer[256];
+    char *buffer;
     Tcl_Obj *limits_obj[2];
 
-    sprintf (buffer, "0x%s", paddr_nz (low));
+    xasprintf (&buffer, "0x%s", paddr_nz (low));
     limits_obj[0] = Tcl_NewStringObj (buffer, -1);
+    free(buffer);
     
-    sprintf (buffer, "0x%s", paddr_nz (high));
+    xasprintf (&buffer, "0x%s", paddr_nz (high));
     limits_obj[1] = Tcl_NewStringObj (buffer, -1);
+    free(buffer);
 
     Tcl_DecrRefCount (result_ptr->obj_ptr);
     result_ptr->obj_ptr = Tcl_NewListObj (2, limits_obj);
@@ -2620,7 +2625,7 @@ gdbtk_load_source (ClientData clientData, struct symtab *symtab, int
 {
   struct disassembly_client_data *client_data =
     (struct disassembly_client_data *) clientData;
-  char buffer[18];
+  char *buffer;
   int index_len;
 
   index_len = Tcl_DStringLength (&client_data->src_to_line_prefix);
@@ -2695,11 +2700,12 @@ gdbtk_load_source (ClientData clientData, struct symtab *symtab, int
              /* FIXME: Convert to Tcl_SetVar2Ex when we move to 8.2.  This
                 will allow us avoid converting widget_line_no into a string. */
              
-             sprintf (buffer, "%d", client_data->widget_line_no);
+            xasprintf (&buffer, "%d", client_data->widget_line_no);
              
              Tcl_SetVar2 (client_data->interp, client_data->map_arr,
                           Tcl_DStringValue (&client_data->src_to_line_prefix),
                           buffer, 0);
+            free(buffer);
              
              Tcl_DStringSetLength (&client_data->src_to_line_prefix, index_len);
            }
@@ -2801,7 +2807,7 @@ gdbtk_load_asm (clientData, pc, di)
 
   if (*client_data->map_arr != '\0')
     {
-      char buffer[16];
+      char *buffer;
       
       /* Run the command, then add an entry to the map array in
         the caller's scope. */
@@ -2811,7 +2817,7 @@ gdbtk_load_asm (clientData, pc, di)
       /* FIXME: Convert to Tcl_SetVar2Ex when we move to 8.2.  This
         will allow us avoid converting widget_line_no into a string. */
       
-      sprintf (buffer, "%d", client_data->widget_line_no);
+      xasprintf (&buffer, "%d", client_data->widget_line_no);
       
       Tcl_SetVar2 (client_data->interp, client_data->map_arr,
                   Tcl_DStringValue (&client_data->pc_to_line_prefix),
@@ -2828,6 +2834,7 @@ gdbtk_load_asm (clientData, pc, di)
       Tcl_DStringSetLength (&client_data->pc_to_line_prefix, pc_to_line_len);      
       Tcl_DStringSetLength (&client_data->line_to_pc_prefix, line_to_pc_len);      
       
+      free(buffer);
     }
   
   do_cleanups (old_chain);
@@ -3684,7 +3691,7 @@ gdb_set_bp (clientData, interp, objc, objv)
   struct symtab_and_line sal;
   int line, ret, thread = -1;
   struct breakpoint *b;
-  char buf[64], *typestr;
+  char *buf, *typestr;
   Tcl_DString cmd;
   enum bpdisp disp;
 
@@ -3744,27 +3751,31 @@ gdb_set_bp (clientData, interp, objc, objv)
   b->thread = thread;
 
   /* FIXME: this won't work for duplicate basenames! */
-  sprintf (buf, "%s:%d", basename (Tcl_GetStringFromObj (objv[1], NULL)),
+  xasprintf (&buf, "%s:%d", basename (Tcl_GetStringFromObj (objv[1], NULL)),
           line);
   b->addr_string = strsave (buf);
+  free(buf);
 
   /* now send notification command back to GUI */
 
   Tcl_DStringInit (&cmd);
 
   Tcl_DStringAppend (&cmd, "gdbtk_tcl_breakpoint create ", -1);
-  sprintf (buf, "%d", b->number);
+  xasprintf (&buf, "%d", b->number);
   Tcl_DStringAppendElement (&cmd, buf);
-  sprintf (buf, "0x%lx", (long) sal.pc);
+  free(buf);
+  xasprintf (&buf, "0x%lx", (long) sal.pc);
   Tcl_DStringAppendElement (&cmd, buf);
   Tcl_DStringAppendElement (&cmd, Tcl_GetStringFromObj (objv[2], NULL));
   Tcl_DStringAppendElement (&cmd, Tcl_GetStringFromObj (objv[1], NULL));
   Tcl_DStringAppendElement (&cmd, bpdisp[b->disposition]);
-  sprintf (buf, "%d", b->enable);
+  free(buf);
+  xasprintf (&buf, "%d", b->enable);
   Tcl_DStringAppendElement (&cmd, buf);
-  sprintf (buf, "%d", b->thread);
+  free(buf);
+  xasprintf (&buf, "%d", b->thread);
   Tcl_DStringAppendElement (&cmd, buf);
-
+  free(buf);
 
   ret = Tcl_Eval (interp, Tcl_DStringValue (&cmd));
   Tcl_DStringFree (&cmd);
@@ -3796,7 +3807,7 @@ gdb_set_bp_addr (clientData, interp, objc, objv)
   int line, ret, thread = -1;
   long addr;
   struct breakpoint *b;
-  char *filename, *typestr, buf[64];
+  char *filename, *typestr, *buf;
   Tcl_DString cmd;
   enum bpdisp disp;
 
@@ -3848,7 +3859,7 @@ gdb_set_bp_addr (clientData, interp, objc, objv)
   b->disposition = disp;
   b->thread = thread;
 
-  sprintf (buf, "*(0x%lx)", addr);
+  xasprintf (&buf, "*(0x%lx)", addr);
   b->addr_string = strsave (buf);
 
   /* now send notification command back to GUI */
@@ -3856,11 +3867,14 @@ gdb_set_bp_addr (clientData, interp, objc, objv)
   Tcl_DStringInit (&cmd);
 
   Tcl_DStringAppend (&cmd, "gdbtk_tcl_breakpoint create ", -1);
-  sprintf (buf, "%d", b->number);
+  free(buf);
+  xasprintf (&buf, "%d", b->number);
   Tcl_DStringAppendElement (&cmd, buf);
-  sprintf (buf, "0x%lx", addr);
+  free(buf);
+  xasprintf (&buf, "0x%lx", addr);
   Tcl_DStringAppendElement (&cmd, buf);
-  sprintf (buf, "%d", b->line_number);
+  free(buf);
+  xasprintf (&buf, "%d", b->line_number);
   Tcl_DStringAppendElement (&cmd, buf);
 
   filename = symtab_to_filename (sal.symtab);
@@ -3868,13 +3882,16 @@ gdb_set_bp_addr (clientData, interp, objc, objv)
     filename = "";
   Tcl_DStringAppendElement (&cmd, filename);
   Tcl_DStringAppendElement (&cmd, bpdisp[b->disposition]);
-  sprintf (buf, "%d", b->enable);
+  free(buf);
+  xasprintf (&buf, "%d", b->enable);
   Tcl_DStringAppendElement (&cmd, buf);
-  sprintf (buf, "%d", b->thread);
+  free(buf);
+  xasprintf (&buf, "%d", b->thread);
   Tcl_DStringAppendElement (&cmd, buf);
 
   ret = Tcl_Eval (interp, Tcl_DStringValue (&cmd));
   Tcl_DStringFree (&cmd);
+  free(buf);
   return ret;
 }
 
@@ -4013,9 +4030,10 @@ gdb_get_breakpoint_info (clientData, interp, objc, objv)
 
   if (!b || b->type != bp_breakpoint)
     {
-      char err_buf[64];
-      sprintf (err_buf, "Breakpoint #%d does not exist.", bpnum);
+      char *err_buf;
+      xasprintf (&err_buf, "Breakpoint #%d does not exist.", bpnum);
       Tcl_SetStringObj (result_ptr->obj_ptr, err_buf, -1);
+      free(err_buf);
       return TCL_ERROR;
     }
 
@@ -4308,15 +4326,16 @@ gdb_selected_frame (clientData, interp, objc, objv)
      int objc;
      Tcl_Obj *CONST objv[];
 {
-  char frame[32];
+  char *frame;
 
   if (selected_frame == NULL)
-    strcpy (frame, "");
+    xasprintf (&frame, "%s","");
   else
-    sprintf (frame, "0x%s", paddr_nz (FRAME_FP (selected_frame)));
+    xasprintf (&frame, "0x%s", paddr_nz (FRAME_FP (selected_frame)));
 
   Tcl_SetStringObj (result_ptr->obj_ptr, frame, -1);
 
+  free(frame);
   return TCL_OK;
 }
 
@@ -4338,20 +4357,20 @@ gdb_selected_block (clientData, interp, objc, objv)
      int objc;
      Tcl_Obj *CONST objv[];
 {
-  char start[32];
-  char end[32];
+  char *start = NULL;
+  char *end   = NULL;
 
   if (selected_frame == NULL)
     {
-      strcpy (start, "");
-      strcpy (end, "");
+      xasprintf (&start, "%s", "");
+      xasprintf (&end, "%s", "");
     }
   else
     {
       struct block *block;
       block = get_frame_block (selected_frame);
-      sprintf (start, "0x%s", paddr_nz (BLOCK_START (block)));
-      sprintf (end, "0x%s", paddr_nz (BLOCK_END (block)));
+      xasprintf (&start, "0x%s", paddr_nz (BLOCK_START (block)));
+      xasprintf (&end, "0x%s", paddr_nz (BLOCK_END (block)));
     }
 
   Tcl_SetListObj (result_ptr->obj_ptr, 0, NULL);
@@ -4360,6 +4379,8 @@ gdb_selected_block (clientData, interp, objc, objv)
   Tcl_ListObjAppendElement (interp, result_ptr->obj_ptr,
                            Tcl_NewStringObj (end, -1));
 
+  free(start);
+  free(end);
   return TCL_OK;
 }
 
@@ -4435,16 +4456,18 @@ gdb_get_blocks (clientData, interp, objc, objv)
          
          if (!junk && pc < BLOCK_END (block))
            {
-             char addr[32];
+            char *addr;
 
              Tcl_Obj *elt = Tcl_NewListObj (0, NULL);
-             sprintf (addr, "0x%s", paddr_nz (BLOCK_START (block)));
+            xasprintf (&addr, "0x%s", paddr_nz (BLOCK_START (block)));
              Tcl_ListObjAppendElement (interp, elt,
                                        Tcl_NewStringObj (addr, -1));
-             sprintf (addr, "0x%s", paddr_nz (BLOCK_END (block)));
+            free(addr);
+            xasprintf (&addr, "0x%s", paddr_nz (BLOCK_END (block)));
              Tcl_ListObjAppendElement (interp, elt,
                                        Tcl_NewStringObj (addr, -1));
              Tcl_ListObjAppendElement (interp, result_ptr->obj_ptr, elt);
+            free(addr);
            }
 
          if (BLOCK_FUNCTION (block))

diff --git a/gdb/gdbtk/generic/gdbtk-hooks.c b/gdb/gdbtk/generic/gdbtk-hooks.c
index 98fd8a8..7de7617 100644 (file)
--- a/gdb/gdbtk/generic/gdbtk-hooks.c
+++ b/gdb/gdbtk/generic/gdbtk-hooks.c
@@ -292,10 +292,12 @@ gdbtk_warning (warning, args)
      const char *warning;
      va_list args;
 {
-  char buf[200];
+  char *buf;
 
-  vsprintf (buf, warning, args);
+  xvasprintf (&buf, warning, args);
   gdbtk_two_elem_cmd ("gdbtk_tcl_warning", buf);
+
+  free(buf);
 }
 
 
@@ -325,10 +327,11 @@ gdbtk_ignorable_warning (class, warning)
      const char *class;
      const char *warning;
 {
-  char buf[512];
-  sprintf (buf, "gdbtk_tcl_ignorable_warning {%s} {%s}", class, warning);
+  char *buf;
+  xasprintf (&buf, "gdbtk_tcl_ignorable_warning {%s} {%s}", class, warning);
   if (Tcl_Eval (gdbtk_interp, buf) != TCL_OK)
     report_error ();
+  free(buf); 
 }
 
 static void
@@ -469,11 +472,12 @@ static void
 gdbtk_readline_begin (char *format,...)
 {
   va_list args;
-  char buf[200];
+  char *buf;
 
   va_start (args, format);
-  vsprintf (buf, format, args);
+  xvasprintf (&buf, format, args);
   gdbtk_two_elem_cmd ("gdbtk_tcl_readline_begin", buf);
+  free(buf);
 }
 
 static char *
@@ -538,7 +542,7 @@ gdbtk_set_hook (struct cmd_list_element *cmdblk)
 {
   Tcl_DString cmd;
   char *p;
-  char buffer[30];
+  char *buffer = NULL;
 
   Tcl_DStringInit (&cmd);
   Tcl_DStringAppendElement (&cmd, "run_hooks");
@@ -550,7 +554,7 @@ gdbtk_set_hook (struct cmd_list_element *cmdblk)
   while (p && *p)
     {
       char *q = strchr (p, ' ');
-      char save;
+      char save = '\0';
       if (q)
        {
          save = *q;
@@ -581,12 +585,12 @@ gdbtk_set_hook (struct cmd_list_element *cmdblk)
 
     case var_uinteger:
     case var_zinteger:
-      sprintf (buffer, "%u", *(unsigned int *) cmdblk->var);
+      xasprintf (&buffer, "%u", *(unsigned int *) cmdblk->var);
       Tcl_DStringAppendElement (&cmd, buffer);
       break;
 
     case var_integer:
-      sprintf (buffer, "%d", *(int *) cmdblk->var);
+      xasprintf (&buffer, "%d", *(int *) cmdblk->var);
       Tcl_DStringAppendElement (&cmd, buffer);
       break;
 
@@ -600,6 +604,11 @@ gdbtk_set_hook (struct cmd_list_element *cmdblk)
     report_error ();
 
   Tcl_DStringFree (&cmd);
+   
+  if (buffer != NULL)
+    {
+       free(buffer);
+    }
 }
 
 /* The next three functions use breakpoint_notify to allow the GUI 
@@ -640,7 +649,7 @@ breakpoint_notify (b, action)
      struct breakpoint *b;
      const char *action;
 {
-  char buf[256];
+  char *buf;
   int v;
   struct symtab_and_line sal;
   char *filename;
@@ -655,21 +664,24 @@ breakpoint_notify (b, action)
   if (filename == NULL)
     filename = "";
 
-  sprintf (buf, "gdbtk_tcl_breakpoint %s %d 0x%lx %d {%s} {%s} %d %d",
+  xasprintf (&buf, "gdbtk_tcl_breakpoint %s %d 0x%lx %d {%s} {%s} %d %d",
           action, b->number, (long) b->address, b->line_number, filename,
           bpdisp[b->disposition], b->enable, b->thread);
 
   if (Tcl_Eval (gdbtk_interp, buf) != TCL_OK)
     report_error ();
+  free(buf); 
 }
 
 int
 gdbtk_load_hash (const char *section, unsigned long num)
 {
-  char buf[128];
-  sprintf (buf, "Download::download_hash %s %ld", section, num);
+  char *buf;
+  xasprintf (&buf, "Download::download_hash %s %ld", section, num);
   if (Tcl_Eval (gdbtk_interp, buf) != TCL_OK)
     report_error ();
+  free(buf); 
+   
   return atoi (gdbtk_interp->result);
 }
 
@@ -721,11 +733,12 @@ gdbtk_query (query, args)
      const char *query;
      va_list args;
 {
-  char buf[200];
+  char *buf;
   long val;
 
-  vsprintf (buf, query, args);
+  xvasprintf (&buf, query, args);
   gdbtk_two_elem_cmd ("gdbtk_tcl_query", buf);
+  free(buf);
 
   val = atol (gdbtk_interp->result);
   return val;
@@ -769,7 +782,7 @@ tracepoint_notify (tp, action)
      struct tracepoint *tp;
      const char *action;
 {
-  char buf[256];
+  char *buf;
   int v;
   struct symtab_and_line sal;
   char *filename;
@@ -781,11 +794,12 @@ tracepoint_notify (tp, action)
   filename = symtab_to_filename (sal.symtab);
   if (filename == NULL)
     filename = "N/A";
-  sprintf (buf, "gdbtk_tcl_tracepoint %s %d 0x%lx %d {%s} %d", action, tp->number,
+  xasprintf (&buf, "gdbtk_tcl_tracepoint %s %d 0x%lx %d {%s} %d", action, tp->number,
           (long) tp->address, sal.line, filename, tp->pass_count);
 
   if (Tcl_Eval (gdbtk_interp, buf) != TCL_OK)
     report_error ();
+  free(buf); 
 }
 
 /*
@@ -886,7 +900,7 @@ gdbtk_error_begin ()
 static void
 gdbtk_annotate_signal ()
 {
-  char buf[128];
+  char *buf;
 
   /* Inform gui that the target has stopped. This is
      a necessary stop button evil. We don't want signal notification
@@ -894,10 +908,11 @@ gdbtk_annotate_signal ()
      timeout. */
   Tcl_Eval (gdbtk_interp, "gdbtk_stop_idle_callback");
 
-  sprintf (buf, "gdbtk_signal %s {%s}", target_signal_to_name (stop_signal),
+  xasprintf (&buf, "gdbtk_signal %s {%s}", target_signal_to_name (stop_signal),
           target_signal_to_string (stop_signal));
   if (Tcl_Eval (gdbtk_interp, buf) != TCL_OK)
     report_error ();
+  free(buf);  
 }
 
 static void

diff --git a/gdb/gdbtk/generic/gdbtk.c b/gdb/gdbtk/generic/gdbtk.c
index 829118d..1dd2af3 100644 (file)
--- a/gdb/gdbtk/generic/gdbtk.c
+++ b/gdb/gdbtk/generic/gdbtk.c
@@ -196,7 +196,7 @@ void
 TclDebug (char level, const char *fmt,...)
 {
   va_list args;
-  char buf[10000], *v[3], *merge, *priority;
+  char *buf, *v[3], *merge, *priority;
 
   switch (level)
     {
@@ -215,17 +215,19 @@ TclDebug (char level, const char *fmt,...)
 
   va_start (args, fmt);
 
+
+  xvasprintf (&buf, fmt, args);
+  va_end (args);
+
   v[0] = "dbug";
   v[1] = priority;
   v[2] = buf;
 
-  vsprintf (buf, fmt, args);
-  va_end (args);
-
   merge = Tcl_Merge (3, v);
   if (Tcl_Eval (gdbtk_interp, merge) != TCL_OK)
     Tcl_BackgroundError (gdbtk_interp);
   Tcl_Free (merge);
+  free(buf);
 }
 \f
 
@@ -359,7 +361,7 @@ gdbtk_init (argv0)
 {
   struct cleanup *old_chain;
   int found_main;
-  char s[5];
+  char *s;
   Tcl_Obj *auto_path_elem, *auto_path_name;
 
   /* If there is no DISPLAY environment variable, Tk_Init below will fail,
@@ -389,8 +391,10 @@ gdbtk_init (argv0)
 
   /* Set up some globals used by gdb to pass info to gdbtk
      for start up options and the like */
-  sprintf (s, "%d", inhibit_gdbinit);
+  xasprintf (&s, "%d", inhibit_gdbinit);
   Tcl_SetVar2 (gdbtk_interp, "GDBStartup", "inhibit_prefs", s, TCL_GLOBAL_ONLY);
+  free(s);
+   
   /* Note: Tcl_SetVar2() treats the value as read-only (making a
      copy).  Unfortunatly it does not mark the parameter as
      ``const''. */