Remove linux_proc_pid_get_ns

This commit removes linux_proc_pid_get_ns, and updates its only
caller to use linux_ns_same instead.

gdb/ChangeLog:

	* linux-thread-db.c (nat/linux-namespaces.h): New include.
	(check_pid_namespace_match): Use linux_ns_same rather than
	linux_proc_pid_get_ns to spot PID namespace mismatches.
	* nat/linux-procfs.h (linux_proc_pid_get_ns): Remove.
	* nat/linux-procfs.c (linux_proc_pid_get_ns): Likewise.

4 files changed, 10 insertions, 35 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 42a5182..d85e4e7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,13 @@
 2015-06-10  Gary Benson <gbenson@redhat.com>
 
+	* linux-thread-db.c (nat/linux-namespaces.h): New include.
+	(check_pid_namespace_match): Use linux_ns_same rather than
+	linux_proc_pid_get_ns to spot PID namespace mismatches.
+	* nat/linux-procfs.h (linux_proc_pid_get_ns): Remove.
+	* nat/linux-procfs.c (linux_proc_pid_get_ns): Likewise.
+
+2015-06-10  Gary Benson <gbenson@redhat.com>
+
 	* configure.ac (AC_CHECK_FUNCS): Add setns.
 	* config.in: Regenerate.
 	* configure: Likewise.
diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index d6387d5..6177f39 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -42,9 +42,9 @@
 #include "nat/linux-osdata.h"
 #include "auto-load.h"
 #include "cli/cli-utils.h"
-
 #include <signal.h>
 #include <ctype.h>
+#include "nat/linux-namespaces.h"
 
 /* GNU/Linux libthread_db support.
 
@@ -1200,20 +1200,12 @@ check_pid_namespace_match (void)
 	 child's thread list, we'll mistakenly think it has no threads
 	 since the thread PID fields won't match the PID we give to
 	 libthread_db.  */
-      char *our_pid_ns = linux_proc_pid_get_ns (getpid (), "pid");
-      char *inferior_pid_ns = linux_proc_pid_get_ns (
-	ptid_get_pid (inferior_ptid), "pid");
-
-      if (our_pid_ns != NULL && inferior_pid_ns != NULL
-	  && strcmp (our_pid_ns, inferior_pid_ns) != 0)
+      if (!linux_ns_same (ptid_get_pid (inferior_ptid), LINUX_NS_PID))
 	{
 	  warning (_ ("Target and debugger are in different PID "
 		      "namespaces; thread lists and other data are "
 		      "likely unreliable"));
 	}
-
-      xfree (our_pid_ns);
-      xfree (inferior_pid_ns);
     }
 }
 
diff --git a/gdb/nat/linux-procfs.c b/gdb/nat/linux-procfs.c
index 44364c5..24bcb01 100644
--- a/gdb/nat/linux-procfs.c
+++ b/gdb/nat/linux-procfs.c
@@ -185,25 +185,6 @@ linux_proc_pid_is_zombie (pid_t pid)
   return linux_proc_pid_is_zombie_maybe_warn (pid, 1);
 }
 
-/* See linux-procfs.h declaration.  */
-
-char *
-linux_proc_pid_get_ns (pid_t pid, const char *ns)
-{
-  char buf[100];
-  char nsval[64];
-  int ret;
-  xsnprintf (buf, sizeof (buf), "/proc/%d/ns/%s", (int) pid, ns);
-  ret = readlink (buf, nsval, sizeof (nsval));
-  if (0 < ret && ret < sizeof (nsval))
-    {
-      nsval[ret] = '\0';
-      return xstrdup (nsval);
-    }
-
-  return NULL;
-}
-
 /* See linux-procfs.h.  */
 
 void
diff --git a/gdb/nat/linux-procfs.h b/gdb/nat/linux-procfs.h
index fdbf383..f9cad39 100644
--- a/gdb/nat/linux-procfs.h
+++ b/gdb/nat/linux-procfs.h
@@ -54,12 +54,6 @@ extern int linux_proc_pid_is_zombie_nowarn (pid_t pid);
 
 extern int linux_proc_pid_is_gone (pid_t pid);
 
-/* Return an opaque string identifying PID's NS namespace or NULL if
- * the information is unavailable.  The returned string must be
- * released with xfree.  */
-
-extern char *linux_proc_pid_get_ns (pid_t pid, const char *ns);
-
 /* Callback function for linux_proc_attach_tgid_threads.  If the PTID
    thread is not yet known, try to attach to it and return true,
    otherwise return false.  */