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.

1 files changed, 7 insertions, 2 deletions

diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 06ec576..d2d4c1d 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -652,6 +652,8 @@ linux_attach_lwp_1 (unsigned long lwpid, int initial)
 
   if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0)
     {
+      struct buffer buffer;
+
       if (!initial)
 	{
 	  /* If we fail to attach to an LWP, just warn.  */
@@ -662,8 +664,11 @@ linux_attach_lwp_1 (unsigned long lwpid, int initial)
 	}
 
       /* If we fail to attach to a process, report an error.  */
-      error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid,
-	     strerror (errno), errno);
+      buffer_init (&buffer);
+      linux_ptrace_attach_warnings (lwpid, &buffer);
+      buffer_grow_str0 (&buffer, "");
+      error ("%sCannot attach to lwp %ld: %s (%d)", buffer_finish (&buffer),
+	     lwpid, strerror (errno), errno);
     }
 
   if (initial)