[src/trunk]: src/sys/compat/mach Don't change process' special ports on exec(...

[manu <manu%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ebfe5368ed57
branches:  trunk
changeset: 555692:ebfe5368ed57
user:      manu <manu%NetBSD.org@localhost>
date:      Tue Nov 25 13:22:38 2003 +0000

description:
Don't change process' special ports on exec(). If gdb attached the process,
it holds rights to the special ports, and it expects the rights to be valid
even after the process calls exec().

diffstat:

 sys/compat/mach/mach_exec.c |  74 +++++++++++++++++++++++---------------------
 1 files changed, 39 insertions(+), 35 deletions(-)

diffs (107 lines):

diff -r 2d421c3355af -r ebfe5368ed57 sys/compat/mach/mach_exec.c
--- a/sys/compat/mach/mach_exec.c       Tue Nov 25 12:52:10 2003 +0000
+++ b/sys/compat/mach/mach_exec.c       Tue Nov 25 13:22:38 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mach_exec.c,v 1.39 2003/11/20 22:05:25 manu Exp $       */
+/*     $NetBSD: mach_exec.c,v 1.40 2003/11/25 13:22:38 manu Exp $       */
 
 /*-
  * Copyright (c) 2001-2003 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mach_exec.c,v 1.39 2003/11/20 22:05:25 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mach_exec.c,v 1.40 2003/11/25 13:22:38 manu Exp $");
 
 #include "opt_syscall_debug.h"
 
@@ -280,51 +280,55 @@
                lockmgr(&med->med_rightlock, LK_RELEASE, NULL);
 
                /*
-                * Do not touch bootstrap port here, as it is 
-                * shared between all processes in our implementation.
-                * We do not want to release it.
+                * Do not touch special ports. Some other process (eg: gdb)
+                * might have grabbed them to control the process, and the
+                * controler intend to keep in control even after exec().
+                */
+       } else {
+               /* 
+                * p->p_emuldata is uninitialized. Go ahaead and initialize it.
                 */
-               if (--med->med_kernel->mp_refcount == 0) 
-                       mach_port_put(med->med_kernel);
-               if (--med->med_host->mp_refcount == 0)  
-                       mach_port_put(med->med_host);  
-       }
+               LIST_INIT(&med->med_right);
+               lockinit(&med->med_rightlock, PZERO|PCATCH, "mach_right", 0, 0);
+
+               /* 
+                * For debugging purpose, it's convenient to have each process 
+                * using distinct port names, so we prefix the first port name
+                * by the PID. Darwin does not do that, but we can remove it 
+                * when we want, it will not hurt.
+                */
+               med->med_nextright = p->p_pid << 16;
 
-       LIST_INIT(&med->med_right);
-       lockinit(&med->med_rightlock, PZERO|PCATCH, "mach_right", 0, 0);
-       /* 
-        * For debugging purpose, it's convenient to have each process 
-        * using distinct port names, so we prefix the first port name
-        * by the PID. Darwin does not do that, but we can remove it 
-        * when we want, it will not hurt.
-        */
-       med->med_nextright = p->p_pid << 16;
+               /*
+                * Initialize special ports. Bootstrap port is shared
+                * among all Mach processes in our implementation.
+                */
+               med->med_kernel = mach_port_get();
+               med->med_host = mach_port_get();
 
-       med->med_kernel = mach_port_get();
-       med->med_host = mach_port_get();
+               med->med_kernel->mp_flags |= MACH_MP_INKERNEL;
+               med->med_host->mp_flags |= MACH_MP_INKERNEL;
 
-       med->med_kernel->mp_flags |= MACH_MP_INKERNEL;
-       med->med_host->mp_flags |= MACH_MP_INKERNEL;
+               med->med_kernel->mp_data = (void *)p;
+               med->med_host->mp_data = (void *)p;
 
-       med->med_kernel->mp_data = (void *)p;
-       med->med_host->mp_data = (void *)p;
+               med->med_kernel->mp_datatype = MACH_MP_PROC;
+               med->med_host->mp_datatype = MACH_MP_PROC;
 
-       med->med_kernel->mp_datatype = MACH_MP_PROC;
-       med->med_host->mp_datatype = MACH_MP_PROC;
+               /* Make sure they will not be deallocated */
+               med->med_kernel->mp_refcount++;
+               med->med_host->mp_refcount++;
 
-       /* Make sure they will not be deallocated */
-       med->med_kernel->mp_refcount++;
-       med->med_host->mp_refcount++;
-
-       med->med_bootstrap = mach_bootstrap_port;
-       med->med_bootstrap->mp_refcount++;
+               med->med_bootstrap = mach_bootstrap_port;
+               med->med_bootstrap->mp_refcount++;
+       }
 
        /* 
         * Exception ports are inherited accross exec() calls.
         * If the structure is initialized, the ports are just 
         * here, so leave them untouched. If the structure is
-        * uninitalized, the ports are all set to zero, so do
-        * not touch them either.
+        * uninitalized, the ports are all set to zero, which 
+        * is the default, so do not touch them either.
         */
 
        med->med_dirty_thid = 1;