* gdb_ptrace.h (PT_TRACE_ME): Define to zero if not already

defined.
* inf-ptrace.c: Tweak comments.
(inf_ptrace_me): Use PT_TRACE_ME instead of hardcoded zero.
(inf_ptrace_mourn_inferior): Call waitpid.
(inf_ptrace_attach): Use pid_t, Remove unnecessary cast.
(inf_ptrace_detach): Use pid_t.  Use ptid_get_pid instead of
PIDGET.
(inf_ptrace_kill): Rename from inf_ptrace_kill_inferior.  Use
pid_t.  Use ptid_get_pid instead of PIDGET.
(inf_ptrace_kill): Call waitpid instead of wait.
(inf_ptrace_resume): Use pid_t.  Use ptid_get_pid instead of
PIDGET.
(inf_ptrace_wait): Use waitpid instead wait.  Use pid_t.  Don't
call target_has_exited or target_thread_alive.  Properly ignore
terminated detached child processes.
(inf_ptrace_has_exited): Remove function.
(inf_ptrace_xfer_partial): Use pid_t.  Use ptid_get_pid instead of
PIDGET.  Use gdb_byte instead of `unsigned char'.
(inf_ptrace_thread_alive): Use ptid_get_pid instead of PIDGET.
(inf_ptrace_pid_to_str): Remove function.
(inf_ptrace_target): Use inf_ptrace_kill instead of
inf_ptrace_kill_inferior.  Use normal_pid_to_str instead of
inf_ptrace_pid_to_str.  Don't set to_has_exited.
(inf_ptrace_fetch_register, inf_ptrace_store_register): Reformat
long lines.

1 files changed, 110 insertions, 153 deletions

diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
index 771a7d6..9c4a77f 100644
--- a/gdb/inf-ptrace.c
+++ b/gdb/inf-ptrace.c
@@ -41,18 +41,16 @@
 static struct target_ops *ptrace_ops_hack;
 
 
-/* Stub function which causes the inferior that runs it, to be ptrace-able
-   by its parent process.  */
+/* Prepare to be traced.  */
 
 static void
 inf_ptrace_me (void)
 {
   /* "Trace me, Dr. Memory!"  */
-  ptrace (0, 0, (PTRACE_TYPE_ARG3) 0, 0);
+  ptrace (PT_TRACE_ME, 0, (PTRACE_TYPE_ARG3)0, 0);
 }
 
-/* Stub function which causes the GDB that runs it, to start ptrace-ing
-   the child process.  */
+/* Start tracing PID.  */
 
 static void
 inf_ptrace_him (int pid)
@@ -76,10 +74,10 @@ inf_ptrace_him (int pid)
   target_post_startup_inferior (pid_to_ptid (pid));
 }
 
-/* Start an inferior Unix child process and sets inferior_ptid to its
-   pid.  EXEC_FILE is the file to run.  ALLARGS is a string containing
-   the arguments to the program.  ENV is the environment vector to
-   pass.  Errors reported with error().  */
+/* Start a new inferior Unix child process.  EXEC_FILE is the file to
+   run, ALLARGS is a string containing the arguments to the program.
+   ENV is the environment vector to pass.  If FROM_TTY is non-zero, be
+   chatty about it.  */
 
 static void
 inf_ptrace_create_inferior (char *exec_file, char *allargs, char **env,
@@ -87,26 +85,39 @@ inf_ptrace_create_inferior (char *exec_file, char *allargs, char **env,
 {
   fork_inferior (exec_file, allargs, env, inf_ptrace_me, inf_ptrace_him,
 		 NULL, NULL);
+
   /* We are at the first instruction we care about.  */
   observer_notify_inferior_created (&current_target, from_tty);
+
   /* Pedal to the metal...  */
   proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0);
 }
 
+/* Clean up a rotting corpse of an inferior after it died.  */
+
 static void
 inf_ptrace_mourn_inferior (void)
 {
+  int status;
+
+  /* Wait just one more time to collect the inferior's exit status.
+     Don not check whether this succeeds though, since we may be
+     dealing with a process that we attached to.  Such a process will
+     only report its exit status to its origional parent.  */
+  waitpid (ptid_get_pid (inferior_ptid), &status, 0);
+
   unpush_target (ptrace_ops_hack);
   generic_mourn_inferior ();
 }
 
-/* Attach to process PID, then initialize for debugging it.  */
+/* Attach to the process specified by ARGS.  If FROM_TTY is non-zero,
+   be chatty about it.  */
 
 static void
 inf_ptrace_attach (char *args, int from_tty)
 {
   char *exec_file;
-  int pid;
+  pid_t pid;
   char *dummy;
 
   if (!args)
@@ -123,7 +134,7 @@ inf_ptrace_attach (char *args, int from_tty)
 
   if (from_tty)
     {
-      exec_file = (char *) get_exec_file (0);
+      exec_file = get_exec_file (0);
 
       if (exec_file)
 	printf_unfiltered (_("Attaching to program: %s, %s\n"), exec_file,
@@ -137,7 +148,7 @@ inf_ptrace_attach (char *args, int from_tty)
 
 #ifdef PT_ATTACH
   errno = 0;
-  ptrace (PT_ATTACH, pid, (PTRACE_TYPE_ARG3) 0, 0);
+  ptrace (PT_ATTACH, pid, (PTRACE_TYPE_ARG3)0, 0);
   if (errno != 0)
     perror_with_name (("ptrace"));
   attach_flag = 1;
@@ -153,18 +164,14 @@ inf_ptrace_attach (char *args, int from_tty)
   observer_notify_inferior_created (&current_target, from_tty);
 }
 
-/* Take a program previously attached to and detaches it.  The program
-   resumes execution and will no longer stop on signals, etc.  We'd
-   better not have left any breakpoints in the program or it'll die
-   when it hits one.  For this to work, it may be necessary for the
-   process to have been previously attached.  It *might* work if the
-   program was started via the normal ptrace (PTRACE_TRACEME).  */
+/* Detach from the inferior, optionally passing it the signal
+   specified ARGS.  If FROM_TTY is non-zero, be chatty about it.  */
 
 static void
 inf_ptrace_detach (char *args, int from_tty)
 {
+  pid_t pid = ptid_get_pid (inferior_ptid);
   int sig = 0;
-  int pid = PIDGET (inferior_ptid);
 
   if (from_tty)
     {
@@ -179,8 +186,12 @@ inf_ptrace_detach (char *args, int from_tty)
     sig = atoi (args);
 
 #ifdef PT_DETACH
+  /* We'd better not have left any breakpoints in the program or it'll
+     die when it hits one.  Alsno note that this may only work if we
+     previously attached to the inferior.  It *might* work if we
+     started the process ourselves.  */
   errno = 0;
-  ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3) 1, sig);
+  ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, sig);
   if (errno != 0)
     perror_with_name (("ptrace"));
   attach_flag = 0;
@@ -192,56 +203,50 @@ inf_ptrace_detach (char *args, int from_tty)
   unpush_target (ptrace_ops_hack);
 }
 
+/* Kill the inferior.  */
+
 static void
-inf_ptrace_kill_inferior (void)
+inf_ptrace_kill (void)
 {
+  pid_t pid = ptid_get_pid (inferior_ptid);
   int status;
-  int pid = PIDGET (inferior_ptid);
 
   if (pid == 0)
     return;
 
-  /* This once used to call "kill" to kill the inferior just in case
-     the inferior was still running.  As others have noted in the past
-     (kingdon) there shouldn't be any way to get here if the inferior
-     is still running -- else there's a major problem elsewere in GDB
-     and it needs to be fixed.
-
-     The kill call causes problems under HP-UX 10, so it's been
-     removed; if this causes problems we'll deal with them as they
-     arise.  */
-  ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3) 0, 0);
-  wait (&status);
+  ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3)0, 0);
+  waitpid (pid, &status, 0);
+
   target_mourn_inferior ();
 }
 
-/* Send a SIGINT to the process group.  This acts just like the user
-   typed a ^C on the controlling terminal.
-
-   FIXME: This may not be correct for all systems.  Some may want to
-   use killpg() instead of kill (-pgrp).  */
+/* Stop the inferior.  */
 
 static void
 inf_ptrace_stop (void)
 {
+  /* Send a SIGINT to the process group.  This acts just like the user
+     typed a ^C on the controlling terminal.  Note that using a
+     negative process number in kill() is a System V-ism.  The proper
+     BSD interface is killpg().  However, all modern BSDs support the
+     System V interface too.  */
   kill (-inferior_process_group, SIGINT);
 }
 
-/* Resume execution of the inferior process.  If STEP is nonzero,
-   single-step it.  If SIGNAL is nonzero, give it that signal.  */
+/* Resume execution of thread PTID, or all threads if PTID is -1.  If
+   STEP is nonzero, single-step it.  If SIGNAL is nonzero, give it
+   that signal.  */
 
 static void
 inf_ptrace_resume (ptid_t ptid, int step, enum target_signal signal)
 {
+  pid_t pid = ptid_get_pid (ptid);
   int request = PT_CONTINUE;
-  int pid = PIDGET (ptid);
 
   if (pid == -1)
-    /* Resume all threads.  */
-    /* I think this only gets used in the non-threaded case, where
-       "resume all threads" and "resume inferior_ptid" are the
-       same.  */
-    pid = PIDGET (inferior_ptid);
+    /* Resume all threads.  Traditionally ptrace() only supports
+       single-threaded processes, so simply resume the inferior.  */
+    pid = ptid_get_pid (inferior_ptid);
 
   if (step)
     {
@@ -255,99 +260,63 @@ inf_ptrace_resume (ptid_t ptid, int step, enum target_signal signal)
 
   /* An address of (PTRACE_TYPE_ARG3)1 tells ptrace to continue from
      where it was.  If GDB wanted it to start some other way, we have
-     already written a new PC value to the child.  */
+     already written a new program counter value to the child.  */
   errno = 0;
-  ptrace (request, pid, (PTRACE_TYPE_ARG3) 1, target_signal_to_host (signal));
+  ptrace (request, pid, (PTRACE_TYPE_ARG3)1, target_signal_to_host (signal));
   if (errno != 0)
     perror_with_name (("ptrace"));
 }
 
-/* Wait for child to do something.  Return pid of child, or -1 in case
-   of error; store status through argument pointer OURSTATUS.  */
+/* Wait for the child specified by PTID to do something.  Return the
+   process ID of the child, or MINUS_ONE_PTID in case of error; store
+   the status in *OURSTATUS.  */
 
 static ptid_t
 inf_ptrace_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
 {
-  int save_errno;
-  int status;
-  char *execd_pathname = NULL;
-  int exit_status;
-  int related_pid;
-  int syscall_id;
-  enum target_waitkind kind;
-  int pid;
+  pid_t pid;
+  int status, save_errno;
 
   do
     {
-      set_sigint_trap ();	/* Causes SIGINT to be passed on to the
-				   attached process. */
+      set_sigint_trap ();
       set_sigio_trap ();
 
-      pid = wait (&status);
-
-      save_errno = errno;
+      do
+	{
+	  pid = waitpid (ptid_get_pid (ptid), &status, 0);
+	  save_errno = errno;
+	}
+      while (pid == -1 && errno == EINTR);
 
       clear_sigio_trap ();
-
       clear_sigint_trap ();
 
       if (pid == -1)
 	{
-	  if (save_errno == EINTR)
-	    continue;
-
 	  fprintf_unfiltered (gdb_stderr,
-			      "Child process unexpectedly missing: %s.\n",
+			      _("Child process unexpectedly missing: %s.\n"),
 			      safe_strerror (save_errno));
 
 	  /* Claim it exited with unknown signal.  */
 	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
 	  ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
-	  return pid_to_ptid (-1);
+	  return minus_one_ptid;
 	}
 
-      /* Did it exit?  */
-      if (target_has_exited (pid, status, &exit_status))
-	{
-	  /* ??rehrauer: For now, ignore this. */
-	  continue;
-	}
-
-      if (!target_thread_alive (pid_to_ptid (pid)))
-	{
-	  ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
-	  return pid_to_ptid (pid);
-	}
+      /* Ignore terminated detached child processes.  */
+      if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid))
+	pid = -1;
     }
-  while (pid != PIDGET (inferior_ptid)); /* Some other child died or
-                                            stopped.  */
+  while (pid == -1);
 
   store_waitstatus (ourstatus, status);
   return pid_to_ptid (pid);
 }
 
-static int
-inf_ptrace_has_exited (int pid, int wait_status, int *exit_status)
-{
-  if (WIFEXITED (wait_status))
-    {
-      *exit_status = WEXITSTATUS (wait_status);
-      return 1;
-    }
-
-  if (WIFSIGNALED (wait_status))
-    {
-      *exit_status = 0;		/* ?? Don't know what else to say here. */
-      return 1;
-    }
-
-  /* ??? Do we really need to consult the event state, too?
-     Assume the wait_state alone suffices.  */
-  return 0;
-}
-
-/* Perform a partial transfer to/from the specified object.  For
-   memory transfers, fall back to the old memory xfer functions.  */
+/* Attempt a transfer all LEN bytes starting at OFFSET between the
+   inferior's OBJECT:ANNEX space and GDB's READBUF/WRITEBUF buffer.
+   Return the number of bytes actually transferred.  */
 
 static LONGEST
 inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
@@ -355,6 +324,8 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
 			 const gdb_byte *writebuf,
 			 ULONGEST offset, LONGEST len)
 {
+  pid_t pid = ptid_get_pid (inferior_ptid);
+
   switch (object)
     {
     case TARGET_OBJECT_MEMORY:
@@ -364,7 +335,7 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
 	 and writing data in the traced process's address space.  */
       {
 	struct ptrace_io_desc piod;
-	
+
 	/* NOTE: We assume that there are no distinct address spaces
 	   for instruction and data.  */
 	piod.piod_op = writebuf ? PIOD_WRITE_D : PIOD_READ_D;
@@ -373,7 +344,7 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
 	piod.piod_len = len;
 
 	errno = 0;
-	if (ptrace (PT_IO, PIDGET (inferior_ptid), (caddr_t) &piod, 0) == 0)
+	if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0)
 	  /* Return the actual number of bytes read or written.  */
 	  return piod.piod_len;
 	/* If the PT_IO request is somehow not supported, fallback on
@@ -387,15 +358,15 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
 	union
 	{
 	  PTRACE_TYPE_RET word;
-	  unsigned char byte[sizeof (PTRACE_TYPE_RET)];
+	  gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
 	} buffer;
 	ULONGEST rounded_offset;
 	LONGEST partial_len;
-	
+
 	/* Round the start offset down to the next long word
 	   boundary.  */
 	rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
-	
+
 	/* Since ptrace will transfer a single word starting at that
 	   rounded_offset the partial_len needs to be adjusted down to
 	   that (remember this function only does a single transfer).
@@ -404,7 +375,7 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
 	partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
 	if (partial_len > len)
 	  partial_len = len;
-	
+
 	if (writebuf)
 	  {
 	    /* If OFFSET:PARTIAL_LEN is smaller than
@@ -414,42 +385,41 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
 		|| (offset + partial_len
 		    < rounded_offset + sizeof (PTRACE_TYPE_RET)))
 	      /* Need part of initial word -- fetch it.  */
-	      buffer.word = ptrace (PT_READ_I, PIDGET (inferior_ptid),
-				    (PTRACE_TYPE_ARG3) (long) rounded_offset,
-				    0);
-	    
+	      buffer.word = ptrace (PT_READ_I, pid,
+				    (PTRACE_TYPE_ARG3)(long)rounded_offset, 0);
+
 	    /* Copy data to be written over corresponding part of
 	       buffer.  */
 	    memcpy (buffer.byte + (offset - rounded_offset),
 		    writebuf, partial_len);
-	    
+
 	    errno = 0;
-	    ptrace (PT_WRITE_D, PIDGET (inferior_ptid),
-		    (PTRACE_TYPE_ARG3) (long) rounded_offset,
-		    buffer.word);
+	    ptrace (PT_WRITE_D, pid,
+		    (PTRACE_TYPE_ARG3)(long)rounded_offset, buffer.word);
 	    if (errno)
 	      {
 		/* Using the appropriate one (I or D) is necessary for
 		   Gould NP1, at least.  */
 		errno = 0;
-		ptrace (PT_WRITE_I, PIDGET (inferior_ptid),
-			(PTRACE_TYPE_ARG3) (long) rounded_offset,
-			buffer.word);
+		ptrace (PT_WRITE_I, pid,
+			(PTRACE_TYPE_ARG3)(long)rounded_offset, buffer.word);
 		if (errno)
 		  return 0;
 	      }
 	  }
+
 	if (readbuf)
 	  {
 	    errno = 0;
-	    buffer.word = ptrace (PT_READ_I, PIDGET (inferior_ptid),
-				  (PTRACE_TYPE_ARG3) (long) rounded_offset, 0);
+	    buffer.word = ptrace (PT_READ_I, pid,
+				  (PTRACE_TYPE_ARG3)(long)rounded_offset, 0);
 	    if (errno)
 	      return 0;
 	    /* Copy appropriate bytes out of the buffer.  */
 	    memcpy (readbuf, buffer.byte + (offset - rounded_offset),
 		    partial_len);
 	  }
+
 	return partial_len;
       }
 
@@ -467,18 +437,13 @@ inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object,
     }
 }
 
-/* Check to see if the given thread is alive.
-
-   FIXME: Is kill() ever the right way to do this?  I doubt it, but
-   for now we're going to try and be compatable with the old thread
-   code.  */
+/* Return non-zero if the thread specified by PTID is alive.  */
 
 static int
 inf_ptrace_thread_alive (ptid_t ptid)
 {
-  pid_t pid = PIDGET (ptid);
-
-  return (kill (pid, 0) != -1);
+  /* ??? Is kill the right way to do this?  */
+  return (kill (ptid_get_pid (ptid), 0) != -1);
 }
 
 /* Print status information about what we're accessing.  */
@@ -486,15 +451,9 @@ inf_ptrace_thread_alive (ptid_t ptid)
 static void
 inf_ptrace_files_info (struct target_ops *ignore)
 {
-  printf_unfiltered (_("\tUsing the running image of %s %s.\n"),
-		     attach_flag ? "attached" : "child",
-		     target_pid_to_str (inferior_ptid));
-}
-
-static char *
-inf_ptrace_pid_to_str (ptid_t ptid)
-{
-  return normal_pid_to_str (ptid);
+  printf_filtered (_("\tUsing the running image of %s %s.\n"),
+		   attach_flag ? "attached" : "child",
+		   target_pid_to_str (inferior_ptid));
 }
 
 /* Create a prototype ptrace target.  The client can override it with
@@ -510,22 +469,20 @@ inf_ptrace_target (void)
   t->to_resume = inf_ptrace_resume;
   t->to_wait = inf_ptrace_wait;
   t->to_files_info = inf_ptrace_files_info;
-  t->to_kill = inf_ptrace_kill_inferior;
+  t->to_kill = inf_ptrace_kill;
   t->to_create_inferior = inf_ptrace_create_inferior;
   t->to_mourn_inferior = inf_ptrace_mourn_inferior;
   t->to_thread_alive = inf_ptrace_thread_alive;
-  t->to_pid_to_str = inf_ptrace_pid_to_str;
+  t->to_pid_to_str = normal_pid_to_str;
   t->to_stop = inf_ptrace_stop;
   t->to_xfer_partial = inf_ptrace_xfer_partial;
 
-  t->to_has_exited = inf_ptrace_has_exited;
-
   ptrace_ops_hack = t;
   return t;
 }
 
 
-/* Pointer to a function that returns the oggset within the user area
+/* Pointer to a function that returns the offset within the user area
    where a particular register is stored.  */
 static CORE_ADDR (*inf_ptrace_register_u_offset)(int);
 
@@ -556,10 +513,10 @@ inf_ptrace_fetch_register (int regnum)
   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
     {
       errno = 0;
-      buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3) addr, 0);
+      buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)addr, 0);
       if (errno != 0)
-	error (_("Couldn't read register %s (#%d): %s."), REGISTER_NAME (regnum),
-	       regnum, safe_strerror (errno));
+	error (_("Couldn't read register %s (#%d): %s."),
+	       REGISTER_NAME (regnum), regnum, safe_strerror (errno));
 
       addr += sizeof (PTRACE_TYPE_RET);
     }
@@ -607,10 +564,10 @@ inf_ptrace_store_register (int regnum)
   for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++)
     {
       errno = 0;
-      ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3) addr, buf[i]);
+      ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)addr, buf[i]);
       if (errno != 0)
-	error (_("Couldn't write register %s (#%d): %s."), REGISTER_NAME (regnum),
-	       regnum, safe_strerror (errno));
+	error (_("Couldn't write register %s (#%d): %s."),
+	       REGISTER_NAME (regnum), regnum, safe_strerror (errno));
 
       addr += sizeof (PTRACE_TYPE_RET);
     }