gdb/

	* common/linux-procfs.c (linux_proc_get_int): New, from
	linux_proc_get_tgid, change its LWPID type to pid_t, add parameter
	field.
	(linux_proc_get_tgid): Only call linux_proc_get_int.
	(linux_proc_get_tracerpid): New.
	(linux_proc_pid_has_state): New, from linux_proc_pid_is_zombie.
	(linux_proc_pid_is_stopped, linux_proc_pid_is_zombie): Only call
	linux_proc_pid_has_state.
	* common/linux-procfs.h (linux_proc_get_tracerpid): New declaration.
	* common/linux-ptrace.c: Include linux-procfs.h and buffer.h.
	(linux_ptrace_attach_warnings): New.
	* common/linux-ptrace.h (struct buffer, linux_ptrace_attach_warnings):
	New declaration.
	* linux-nat.c: Include exceptions.h, linux-ptrace.h and buffer.h.
	(linux_nat_attach): New variables ex, buffer, message and message_s.
	Wrap to_attach by TRY_CATCH and call linux_ptrace_attach_warnings.

gdb/gdbserver/
	* linux-low.c (linux_attach_lwp_1): New variable buffer.  Call
	linux_ptrace_attach_warnings.

gdb/testsuite/
	* gdb.base/attach-twice.c: New files.
	* gdb.base/attach-twice.exp: New files.

3 files changed, 99 insertions, 0 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 16a32e4..d30037b 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-03-06  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* gdb.base/attach-twice.c: New files.
+	* gdb.base/attach-twice.exp: New files.
+
 2012-03-08  Keith Seitz  <keiths@redhat.com>
 
 	* lib/gdb.exp (gdb_get_line_number): Throw an
diff --git a/gdb/testsuite/gdb.base/attach-twice.c b/gdb/testsuite/gdb.base/attach-twice.c
new file mode 100644
index 0000000..cff2215
--- /dev/null
+++ b/gdb/testsuite/gdb.base/attach-twice.c
@@ -0,0 +1,42 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2011-2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/ptrace.h>
+#include <errno.h>
+
+int
+main (void)
+{
+  long l;
+
+  switch (fork ())
+  {
+    case -1:
+      perror ("fork");
+      exit (1);
+    case 0:
+      errno = 0;
+      ptrace (PTRACE_ATTACH, getppid (), NULL, NULL);
+      if (errno != 0)
+	perror ("PTRACE_ATTACH");
+      break;
+  }
+  sleep (600);
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/attach-twice.exp b/gdb/testsuite/gdb.base/attach-twice.exp
new file mode 100644
index 0000000..65dfe25
--- /dev/null
+++ b/gdb/testsuite/gdb.base/attach-twice.exp
@@ -0,0 +1,52 @@
+# Copyright (C) 2012 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Manipulation with PID on target is not supported.
+if [is_remote target] then {
+    return 0
+}
+
+set testfile attach-twice
+set executable ${testfile}
+set binfile ${objdir}/${subdir}/${executable}
+
+if { [prepare_for_testing ${testfile}.exp $executable] } {
+    return -1
+}
+
+set testpid [eval exec $binfile &]
+exec sleep 2
+
+set parentpid 0
+
+set test "attach"
+gdb_test_multiple "attach $testpid" $test {
+    -re "Attaching to program: \[^\r\n\]*, process $testpid\r\n.*warning: process $testpid is already traced by process (\[0-9\]+)\r\n.*ptrace: Operation not permitted\\.\r\n$gdb_prompt $" {
+	set parentpid $expect_out(1,string)
+	pass $test
+    }
+    -re "Attaching to program: \[^\r\n\]*, process $testpid\r\n.*ptrace: Operation not permitted\\.\r\n$gdb_prompt $" {
+	fail $test
+    }
+    -re "\r\n$gdb_prompt $" {
+	xfail $test
+    }
+}
+
+eval exec ps xfw
+if {$parentpid != 0} {
+  eval exec kill -9 $parentpid
+}
+eval exec kill -9 $testpid