[rfc] GDB memory corruption in multi-forks test case

Index: gdb/inflow.c
===================================================================
RCS file: /cvs/src/src/gdb/inflow.c,v
retrieving revision 1.65
diff -u -p -r1.65 inflow.c
--- gdb/inflow.c	31 Jan 2011 03:11:39 -0000	1.65
+++ gdb/inflow.c	4 Mar 2011 15:58:35 -0000
@@ -224,10 +224,9 @@  terminal_init_inferior_with_pgrp (int pg
       struct inferior *inf = current_inferior ();
       struct terminal_info *tinfo = get_inflow_inferior_data (inf);
 
-      /* We could just as well copy our_ttystate (if we felt like
-         adding a new function serial_copy_tty_state()).  */
       xfree (tinfo->ttystate);
-      tinfo->ttystate = serial_get_tty_state (stdin_serial);
+      tinfo->ttystate = serial_copy_tty_state (stdin_serial,
+					       our_terminal_info.ttystate);
 
 #ifdef PROCESS_GROUP_TYPE
       tinfo->process_group = pgrp;
@@ -249,8 +248,6 @@  terminal_save_ours (void)
 {
   if (gdb_has_a_terminal ())
     {
-      /* We could just as well copy our_ttystate (if we felt like adding
-         a new function serial_copy_tty_state).  */
       xfree (our_terminal_info.ttystate);
       our_terminal_info.ttystate = serial_get_tty_state (stdin_serial);
     }
@@ -495,6 +492,7 @@  inflow_inferior_data_cleanup (struct inf
   if (info != NULL)
     {
       xfree (info->run_terminal);
+      xfree (info->ttystate);
       xfree (info);
     }
 }
@@ -532,6 +530,7 @@  inflow_inferior_exit (struct inferior *i
   if (info != NULL)
     {
       xfree (info->run_terminal);
+      xfree (info->ttystate);
       xfree (info);
       set_inferior_data (inf, inflow_inferior_data, NULL);
     }
@@ -544,10 +543,19 @@  copy_terminal_info (struct inferior *to,
 
   tinfo_to = get_inflow_inferior_data (to);
   tinfo_from = get_inflow_inferior_data (from);
+
+  xfree (tinfo_to->run_terminal);
+  xfree (tinfo_to->ttystate);
+
   *tinfo_to = *tinfo_from;
+
   if (tinfo_from->run_terminal)
     tinfo_to->run_terminal
       = xstrdup (tinfo_from->run_terminal);
+
+  if (tinfo_from->ttystate)
+    tinfo_to->ttystate
+      = serial_copy_tty_state (stdin_serial, tinfo_from->ttystate);
 }
 
 void
Index: gdb/ser-base.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-base.c,v
retrieving revision 1.21
diff -u -p -r1.21 ser-base.c
--- gdb/ser-base.c	11 Jan 2011 21:53:23 -0000	1.21
+++ gdb/ser-base.c	4 Mar 2011 15:58:35 -0000
@@ -463,6 +463,13 @@  ser_base_get_tty_state (struct serial *s
   return (serial_ttystate) XMALLOC (int);
 }
 
+serial_ttystate
+ser_base_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
+{
+  /* Allocate another dummy.  */
+  return (serial_ttystate) XMALLOC (int);
+}
+
 int
 ser_base_set_tty_state (struct serial *scb, serial_ttystate ttystate)
 {
Index: gdb/ser-base.h
===================================================================
RCS file: /cvs/src/src/gdb/ser-base.h,v
retrieving revision 1.11
diff -u -p -r1.11 ser-base.h
--- gdb/ser-base.h	1 Jan 2011 15:33:14 -0000	1.11
+++ gdb/ser-base.h	4 Mar 2011 15:58:35 -0000
@@ -32,6 +32,8 @@  extern int ser_base_flush_input (struct 
 extern int ser_base_send_break (struct serial *scb);
 extern void ser_base_raw (struct serial *scb);
 extern serial_ttystate ser_base_get_tty_state (struct serial *scb);
+extern serial_ttystate ser_base_copy_tty_state (struct serial *scb,
+						serial_ttystate ttystate);
 extern int ser_base_set_tty_state (struct serial *scb,
 				   serial_ttystate ttystate);
 extern void ser_base_print_tty_state (struct serial *scb,
Index: gdb/ser-go32.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-go32.c,v
retrieving revision 1.27
diff -u -p -r1.27 ser-go32.c
--- gdb/ser-go32.c	11 Jan 2011 21:53:23 -0000	1.27
+++ gdb/ser-go32.c	4 Mar 2011 15:58:35 -0000
@@ -652,6 +652,17 @@  dos_get_tty_state (struct serial *scb)
   return (serial_ttystate) state;
 }
 
+static serial_ttystate
+dos_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
+{
+  struct dos_ttystate *state;
+
+  state = (struct dos_ttystate *) xmalloc (sizeof *state);
+  *state = *(struct dos_ttystate *) ttystate;
+
+  return (serial_ttystate) state;
+}
+
 static int
 dos_set_tty_state (struct serial *scb, serial_ttystate ttystate)
 {
@@ -851,6 +862,7 @@  static struct serial_ops dos_ops =
   dos_sendbreak,
   dos_raw,
   dos_get_tty_state,
+  dos_copy_tty_state,
   dos_set_tty_state,
   dos_print_tty_state,
   dos_noflush_set_tty_state,
Index: gdb/ser-mingw.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-mingw.c,v
retrieving revision 1.28
diff -u -p -r1.28 ser-mingw.c
--- gdb/ser-mingw.c	21 Feb 2011 13:40:31 -0000	1.28
+++ gdb/ser-mingw.c	4 Mar 2011 15:58:35 -0000
@@ -1244,6 +1244,7 @@  _initialize_ser_windows (void)
   /* These are only used for stdin; we do not need them for serial
      ports, so supply the standard dummies.  */
   ops->get_tty_state = ser_base_get_tty_state;
+  ops->copy_tty_state = ser_base_copy_tty_state;
   ops->set_tty_state = ser_base_set_tty_state;
   ops->print_tty_state = ser_base_print_tty_state;
   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
@@ -1272,6 +1273,7 @@  _initialize_ser_windows (void)
 
   ops->close = ser_console_close;
   ops->get_tty_state = ser_console_get_tty_state;
+  ops->copy_tty_state = ser_base_copy_tty_state;
   ops->set_tty_state = ser_base_set_tty_state;
   ops->print_tty_state = ser_base_print_tty_state;
   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
@@ -1297,6 +1299,7 @@  _initialize_ser_windows (void)
   ops->send_break = ser_base_send_break;
   ops->go_raw = ser_base_raw;
   ops->get_tty_state = ser_base_get_tty_state;
+  ops->copy_tty_state = ser_base_copy_tty_state;
   ops->set_tty_state = ser_base_set_tty_state;
   ops->print_tty_state = ser_base_print_tty_state;
   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
@@ -1331,6 +1334,7 @@  _initialize_ser_windows (void)
   ops->send_break = ser_tcp_send_break;
   ops->go_raw = ser_base_raw;
   ops->get_tty_state = ser_base_get_tty_state;
+  ops->copy_tty_state = ser_base_copy_tty_state;
   ops->set_tty_state = ser_base_set_tty_state;
   ops->print_tty_state = ser_base_print_tty_state;
   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
Index: gdb/ser-pipe.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-pipe.c,v
retrieving revision 1.31
diff -u -p -r1.31 ser-pipe.c
--- gdb/ser-pipe.c	11 Jan 2011 21:53:23 -0000	1.31
+++ gdb/ser-pipe.c	4 Mar 2011 15:58:35 -0000
@@ -214,6 +214,7 @@  _initialize_ser_pipe (void)
   ops->send_break = ser_base_send_break;
   ops->go_raw = ser_base_raw;
   ops->get_tty_state = ser_base_get_tty_state;
+  ops->copy_tty_state = ser_base_copy_tty_state;
   ops->set_tty_state = ser_base_set_tty_state;
   ops->print_tty_state = ser_base_print_tty_state;
   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
Index: gdb/ser-tcp.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-tcp.c,v
retrieving revision 1.38
diff -u -p -r1.38 ser-tcp.c
--- gdb/ser-tcp.c	11 Jan 2011 21:53:23 -0000	1.38
+++ gdb/ser-tcp.c	4 Mar 2011 15:58:35 -0000
@@ -390,6 +390,7 @@  _initialize_ser_tcp (void)
   ops->send_break = ser_tcp_send_break;
   ops->go_raw = ser_base_raw;
   ops->get_tty_state = ser_base_get_tty_state;
+  ops->copy_tty_state = ser_base_copy_tty_state;
   ops->set_tty_state = ser_base_set_tty_state;
   ops->print_tty_state = ser_base_print_tty_state;
   ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
Index: gdb/ser-unix.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-unix.c,v
retrieving revision 1.38
diff -u -p -r1.38 ser-unix.c
--- gdb/ser-unix.c	11 Jan 2011 21:53:23 -0000	1.38
+++ gdb/ser-unix.c	4 Mar 2011 15:58:36 -0000
@@ -188,6 +188,17 @@  hardwire_get_tty_state (struct serial *s
   return (serial_ttystate) state;
 }
 
+static serial_ttystate
+hardwire_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
+{
+  struct hardwire_ttystate *state;
+
+  state = (struct hardwire_ttystate *) xmalloc (sizeof *state);
+  *state = *(struct hardwire_ttystate *) ttystate;
+
+  return (serial_ttystate) state;
+}
+
 static int
 hardwire_set_tty_state (struct serial *scb, serial_ttystate ttystate)
 {
@@ -911,6 +922,7 @@  _initialize_ser_hardwire (void)
   ops->send_break = hardwire_send_break;
   ops->go_raw = hardwire_raw;
   ops->get_tty_state = hardwire_get_tty_state;
+  ops->copy_tty_state = hardwire_copy_tty_state;
   ops->set_tty_state = hardwire_set_tty_state;
   ops->print_tty_state = hardwire_print_tty_state;
   ops->noflush_set_tty_state = hardwire_noflush_set_tty_state;
Index: gdb/serial.c
===================================================================
RCS file: /cvs/src/src/gdb/serial.c,v
retrieving revision 1.43
diff -u -p -r1.43 serial.c
--- gdb/serial.c	27 Feb 2011 16:25:37 -0000	1.43
+++ gdb/serial.c	4 Mar 2011 15:58:36 -0000
@@ -493,6 +493,12 @@  serial_get_tty_state (struct serial *scb
   return scb->ops->get_tty_state (scb);
 }
 
+serial_ttystate
+serial_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
+{
+  return scb->ops->copy_tty_state (scb, ttystate);
+}
+
 int
 serial_set_tty_state (struct serial *scb, serial_ttystate ttystate)
 {
Index: gdb/serial.h
===================================================================
RCS file: /cvs/src/src/gdb/serial.h,v
retrieving revision 1.27
diff -u -p -r1.27 serial.h
--- gdb/serial.h	11 Jan 2011 21:53:23 -0000	1.27
+++ gdb/serial.h	4 Mar 2011 15:58:36 -0000
@@ -129,6 +129,12 @@  extern void serial_raw (struct serial *s
 
 extern serial_ttystate serial_get_tty_state (struct serial *scb);
 
+/* Return a pointer to a newly malloc'd ttystate containing a copy
+   of the state in TTYSTATE.  */
+
+extern serial_ttystate serial_copy_tty_state (struct serial *scb,
+					      serial_ttystate ttystate);
+
 /* Set the state of the tty to TTYSTATE.  The change is immediate.
    When changing to or from raw mode, input might be discarded.
    Returns 0 for success, negative value for error (in which case
@@ -250,6 +256,7 @@  struct serial_ops
     int (*send_break) (struct serial *);
     void (*go_raw) (struct serial *);
     serial_ttystate (*get_tty_state) (struct serial *);
+    serial_ttystate (*copy_tty_state) (struct serial *, serial_ttystate);
     int (*set_tty_state) (struct serial *, serial_ttystate);
     void (*print_tty_state) (struct serial *, serial_ttystate,
 			     struct ui_file *);