[PATCH 4/9] startup: do not pass signals on to the child

[Justus Winter]

Formerly /hurd/startup would forward all signals to the child it
started (e.g. /libexec/runsystem).

The motivation for doing so is not revealed in the comments, nor it is
mentioned in the history of the version control system.

This patch removes the forwarding of signals to the child.

* startup/startup.c (process_signal): Do not pass signals on to the child.
* startup/stubs.c: Remove file.
* startup/Makefile: Remove stubs.c.
---
 startup/Makefile  |    2 +-
 startup/startup.c |   49 -------------------
 startup/stubs.c   |  139 -----------------------------------------------------
 3 files changed, 1 insertion(+), 189 deletions(-)
 delete mode 100644 startup/stubs.c

diff --git a/startup/Makefile b/startup/Makefile
index 2d6b892..277fee4 100644
--- a/startup/Makefile
+++ b/startup/Makefile
@@ -18,7 +18,7 @@
 dir := startup
 makemode := server
 
-SRCS = startup.c stubs.c
+SRCS = startup.c
 OBJS = $(SRCS:.c=.o) \
        startupServer.o notifyServer.o startup_replyUser.o msgServer.o \
        startup_notifyUser.o
diff --git a/startup/startup.c b/startup/startup.c
index 979ae49..f54e650 100644
--- a/startup/startup.c
+++ b/startup/startup.c
@@ -904,9 +904,6 @@ frob_kernel_process (void)
 static pid_t child_pid;                /* PID of the child we run */
 static task_t child_task;              /* and its (original) task port */
 
-error_t send_signal (mach_port_t msgport, int signal, mach_port_t refport,
-                    mach_msg_timeout_t);
-
 static void launch_something (const char *why);
 
 
@@ -964,52 +961,6 @@ process_signal (int signo)
            }
        }
     }
-  else
-    {
-      /* Pass the signal on to the child.  */
-      task_t task;
-      error_t err;
-
-      err = proc_pid2task (procserver, child_pid, &task);
-      if (err)
-       {
-         error (0, err, "proc_pid2task on %d", child_pid);
-         task = child_task;
-       }
-      else
-       {
-         mach_port_deallocate (mach_task_self (), child_task);
-         child_task = task;
-       }
-
-      if (signo == SIGKILL)
-       {
-         err = task_terminate (task);
-         if (err != MACH_SEND_INVALID_DEST)
-           error (0, err, "task_terminate");
-       }
-      else
-       {
-         mach_port_t msgport;
-         err = proc_getmsgport (procserver, child_pid, &msgport);
-         if (err)
-           error (0, err, "proc_getmsgport");
-         else
-           {
-             err = send_signal (msgport, signo, task,
-                                500); /* Block only half a second.  */
-             mach_port_deallocate (mach_task_self (), msgport);
-             if (err)
-               {
-                 error (0, err, "cannot send %s to child %d",
-                        strsignal (signo), child_pid);
-                 err = task_terminate (task);
-                 if (err != MACH_SEND_INVALID_DEST)
-                   error (0, err, "task_terminate");
-               }
-           }
-       }
-    }
 }
 
 /* Start the child program PROG.  It is run via /libexec/console-run
diff --git a/startup/stubs.c b/startup/stubs.c
deleted file mode 100644
index 5292ab6..0000000
--- a/startup/stubs.c
+++ /dev/null
@@ -1,139 +0,0 @@
-/* By-hand stubs for some RPC calls
-   Copyright (C) 1994,96,99,2000 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 2, 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, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
-
-#include <stdlib.h>
-#include <hurd/hurd_types.h>
-#include <mach.h>
-#include <string.h>
-#include <assert.h>
-
-/* From hurd/msg.defs: */
-#define RPCID_SIG_POST 23000
-
-
-/* Send signal SIGNO to MSGPORT with REFPORT as reference.  Don't
-   block in any fashion.  */
-error_t
-send_signal (mach_port_t msgport,
-            int signal,
-            mach_port_t refport,
-            mach_msg_timeout_t timeout)
-{
-  error_t err;
-
-  /* This message buffer might be modified by mach_msg in some error cases,
-     so we cannot safely reuse a static buffer.  */
-  struct
-    {
-      mach_msg_header_t head;
-      mach_msg_type_t signaltype;
-      int signal;
-      mach_msg_type_t sigcode_type;
-      natural_t sigcode;
-      mach_msg_type_t refporttype;
-      mach_port_t refport;
-    }
-  message =
-  {
-    {
-      /* Message header: */
-      (MACH_MSGH_BITS_COMPLEX
-       | MACH_MSGH_BITS (MACH_MSG_TYPE_COPY_SEND,
-                        MACH_MSG_TYPE_MAKE_SEND_ONCE)), /* msgh_bits */
-      sizeof message,          /* msgh_size */
-      msgport,                 /* msgh_remote_port */
-      MACH_PORT_NULL,          /* msgh_local_port */
-      0,                       /* msgh_seqno */
-      RPCID_SIG_POST,          /* msgh_id */
-    },
-    {
-      /* Type descriptor for signo */
-      MACH_MSG_TYPE_INTEGER_32, /* msgt_name */
-      32,                      /* msgt_size */
-      1,                       /* msgt_number */
-      1,                       /* msgt_inline */
-      0,                       /* msgt_longform */
-      0,                       /* msgt_deallocate */
-      0,                       /* msgt_unused */
-    },
-    /* Signal number */
-    signal,
-    /* Type descriptor for sigcode */
-    {
-      MACH_MSG_TYPE_INTEGER_32, /* msgt_name */
-      32,                      /* msgt_size */
-      1,                       /* msgt_number */
-      1,                       /* msgt_inline */
-      0,                       /* msgt_longform */
-      0,                       /* msgt_deallocate */
-      0,                       /* msgt_unused */
-    },
-    /* Sigcode */
-    0,
-    {
-      /* Type descriptor for refport */
-      MACH_MSG_TYPE_COPY_SEND, /* msgt_name */
-      32,                      /* msgt_size */
-      1,                       /* msgt_number */
-      1,                       /* msgt_inline */
-      0,                       /* msgt_longform */
-      0,                       /* msgt_deallocate */
-      0,                       /* msgt_unused */
-    },
-    /* Reference port */
-    refport
-  };
-
-  err = mach_msg (&message.head,
-                 MACH_SEND_MSG|MACH_SEND_TIMEOUT, sizeof message, 0,
-                 MACH_PORT_NULL, timeout, MACH_PORT_NULL);
-
-  switch (err)
-    {
-    case MACH_SEND_TIMED_OUT:
-      /* The send could not complete in time.  In this error case, the
-        kernel has modified the message buffer in a pseudo-receive
-        operation.  That means our COPY_SEND refs might now be MOVE_SEND
-        refs, in which case each has gained user ref accordingly.  To
-        avoid leaking those refs, we must clean up the buffer.  We don't
-        use mach_msg_destroy because it assumes the local/remote ports in
-        the header have been reversed as from a real receive, while a
-        pseudo-receive leaves them as they were.  */
-      if (MACH_MSGH_BITS_REMOTE (message.head.msgh_bits)
-         == MACH_MSG_TYPE_MOVE_SEND)
-       mach_port_deallocate (mach_task_self (),
-                             message.head.msgh_remote_port);
-      if (message.refporttype.msgt_name == MACH_MSG_TYPE_MOVE_SEND)
-       mach_port_deallocate (mach_task_self (), message.refport);
-      break;
-
-      /* These are the other codes that mean a pseudo-receive modified
-        the message buffer and we might need to clean up the send rights.
-        None of them should be possible in our usage.  */
-    case MACH_SEND_INTERRUPTED:
-    case MACH_SEND_INVALID_NOTIFY:
-    case MACH_SEND_NO_NOTIFY:
-    case MACH_SEND_NOTIFY_IN_PROGRESS:
-      assert_perror (err);
-      break;
-
-    default:                   /* Other errors are safe to ignore.  */
-      break;
-    }
-
-  return err;
-}
-- 
1.7.10.4