Don't write to inferior_ptid in nto-procfs.c

A best effort patch, which fixes some bit rot and removes some
inferior_ptid references -- this port clearly hasn't been built in a
long while.

gdb/ChangeLog:
2020-06-18  Pedro Alves  <palves@redhat.com>

	* nto-procfs.c (nto_procfs_target::update_thread_list): Avoid
	inferior_ptid.
	(nto_procfs_target::attach): Avoid inferior_ptid.  Switch to
	thread.
	(nto_procfs_target::detach): Avoid referencing
	inferior_ptid.  Use switch_to_no_thread instead of writing to
	inferior_ptid directly.
	(nto_procfs_target::mourn_inferior): Use switch_to_no_thread
	instead of writing to inferior_ptid directly.
	(nto_procfs_target::create_inferior): Avoid inferior_ptid.  Switch
	to thread.

2 files changed, 26 insertions, 12 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2d99bf3..dc0202d 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,19 @@
 2020-06-18  Pedro Alves  <palves@redhat.com>
 
+	* nto-procfs.c (nto_procfs_target::update_thread_list): Avoid
+	inferior_ptid.
+	(nto_procfs_target::attach): Avoid inferior_ptid.  Switch to
+	thread.
+	(nto_procfs_target::detach): Avoid referencing
+	inferior_ptid.  Use switch_to_no_thread instead of writing to
+	inferior_ptid directly.
+	(nto_procfs_target::mourn_inferior): Use switch_to_no_thread
+	instead of writing to inferior_ptid directly.
+	(nto_procfs_target::create_inferior): Avoid inferior_ptid.  Switch
+	to thread.
+
+2020-06-18  Pedro Alves  <palves@redhat.com>
+
 	* remote-sim.c (gdbsim_target::create_inferior): Switch to thread
 	after creating it, instead of writing to inferior_ptid.
 	(gdbsim_target_open): Use switch_to_no_thread instead of writing
diff --git a/gdb/nto-procfs.c b/gdb/nto-procfs.c
index 58e572c..f649b6c 100644
--- a/gdb/nto-procfs.c
+++ b/gdb/nto-procfs.c
@@ -393,7 +393,7 @@ nto_procfs_target::update_thread_list ()
 
   prune_threads ();
 
-  pid = inferior_ptid.pid ();
+  pid = current_inferior ()->pid;
 
   status.tid = 1;
 
@@ -712,7 +712,7 @@ nto_procfs_target::attach (const char *args, int from_tty)
 	printf_unfiltered ("Attaching to %s\n",
 			   target_pid_to_str (ptid_t (pid)).c_str ());
     }
-  inferior_ptid = do_attach (ptid_t (pid));
+  ptid_t ptid = do_attach (ptid_t (pid));
   inf = current_inferior ();
   inferior_appeared (inf, pid);
   inf->attach_flag = 1;
@@ -720,7 +720,9 @@ nto_procfs_target::attach (const char *args, int from_tty)
   if (!target_is_pushed (ops))
     push_target (ops);
 
-  procfs_update_thread_list (ops);
+  update_thread_list ();
+
+  switch_to_thread (find_thread_ptid (this, ptid));
 }
 
 void
@@ -1000,19 +1002,16 @@ nto_procfs_target::xfer_partial (enum target_object object,
 void
 nto_procfs_target::detach (inferior *inf, int from_tty)
 {
-  int pid;
-
   target_announce_detach ();
 
   if (siggnal)
-    SignalKill (nto_node (), inferior_ptid.pid (), 0, 0, 0, 0);
+    SignalKill (nto_node (), inf->pid, 0, 0, 0, 0);
 
   close (ctl_fd);
   ctl_fd = -1;
 
-  pid = inferior_ptid.pid ();
-  inferior_ptid = null_ptid;
-  detach_inferior (pid);
+  switch_to_no_thread ();
+  detach_inferior (inf->pid);
   init_thread_list ();
   inf_child_maybe_unpush_target (ops);
 }
@@ -1132,7 +1131,7 @@ nto_procfs_target::mourn_inferior ()
       SignalKill (nto_node (), inferior_ptid.pid (), 0, SIGKILL, 0, 0);
       close (ctl_fd);
     }
-  inferior_ptid = null_ptid;
+  switch_to_no_thread ();
   init_thread_list ();
   inf_child_mourn_inferior (ops);
 }
@@ -1303,8 +1302,9 @@ nto_procfs_target::create_inferior (const char *exec_file,
   if (fds[2] != STDERR_FILENO)
     close (fds[2]);
 
-  inferior_ptid = do_attach (ptid_t (pid));
-  procfs_update_thread_list (ops);
+  ptid_t ptid = do_attach (ptid_t (pid));
+  update_thread_list ();
+  switch_to_thread (find_thread_ptid (this, ptid));
 
   inf = current_inferior ();
   inferior_appeared (inf, pid);