[src/trunk]: src/sys/compat/mach Avoid leaking some Mach ports allocated in t...

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

details:   https://anonhg.NetBSD.org/src/rev/ed081126e78f
branches:  trunk
changeset: 555470:ed081126e78f
user:      manu <manu%NetBSD.org@localhost>
date:      Tue Nov 18 14:11:33 2003 +0000

description:
Avoid leaking some Mach ports allocated in the kernel on fork, exec and
exit operations.

diffstat:

 sys/compat/mach/mach_exec.c |  49 ++++++++++++++++++++++++++++++++++++++++----
 sys/compat/mach/mach_exec.h |   3 +-
 2 files changed, 46 insertions(+), 6 deletions(-)

diffs (123 lines):

diff -r a59873dfcb20 -r ed081126e78f sys/compat/mach/mach_exec.c
--- a/sys/compat/mach/mach_exec.c       Tue Nov 18 13:21:53 2003 +0000
+++ b/sys/compat/mach/mach_exec.c       Tue Nov 18 14:11:33 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mach_exec.c,v 1.36 2003/11/18 01:40:18 manu Exp $       */
+/*     $NetBSD: mach_exec.c,v 1.37 2003/11/18 14:11:33 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 1.36 2003/11/18 01:40:18 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mach_exec.c,v 1.37 2003/11/18 14:11:33 manu Exp $");
 
 #include "opt_syscall_debug.h"
 
@@ -227,6 +227,7 @@
        struct vmspace *vmspace;
 {
        struct mach_emuldata *med;
+       struct mach_right *mr;
 
        /* 
         * Initialize various things if needed. 
@@ -235,12 +236,37 @@
        if (mach_cold == 1)
                mach_init();
 
-       if (!p->p_emuldata)
+       /*
+        * For Darwin binaries, p->p_emuldata is aways allocated:
+        * from the previous programm if it had the same emulation,
+        * or from darwin_e_proc_exec(). In the latter situation, 
+        * everything has been set to zero.
+        */
+       if (!p->p_emuldata) 
                p->p_emuldata = malloc(sizeof(struct mach_emuldata),
                    M_EMULDATA, M_WAITOK | M_ZERO);
 
        med = (struct mach_emuldata *)p->p_emuldata;
 
+       /*
+        * p->p_emudata has med_inited set if we inherited it from 
+        * the program that called exec(). In that situation, we
+        * must free anything that will not be used anymore.
+        */
+       if (med->med_inited != 0) {
+               lockmgr(&med->med_rightlock, LK_EXCLUSIVE, NULL);
+               while ((mr = LIST_FIRST(&med->med_right)) != NULL)
+                       mach_right_put_exclocked(mr, MACH_PORT_TYPE_ALL_RIGHTS);
+               lockmgr(&med->med_rightlock, LK_RELEASE, NULL);
+
+               if (--med->med_bootstrap->mp_refcount == 0)
+                       mach_port_put(med->med_bootstrap);
+               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);
        /* 
@@ -270,10 +296,18 @@
        med->med_bootstrap = mach_bootstrap_port;
        med->med_bootstrap->mp_refcount++;
 
-       bzero(med->med_exc, sizeof(med->med_exc));
+       /* 
+        * 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.
+        */
 
        med->med_dirty_thid = 1;
        med->med_suspend = 0;
+       med->med_inited = 1;
+
        return;
 }
 
@@ -291,7 +325,6 @@
        lockmgr(&med->med_rightlock, LK_EXCLUSIVE, NULL);
        while ((mr = LIST_FIRST(&med->med_right)) != NULL)
                mach_right_put_exclocked(mr, MACH_PORT_TYPE_ALL_RIGHTS);
-       
        lockmgr(&med->med_rightlock, LK_RELEASE, NULL);
 
        if (--med->med_bootstrap->mp_refcount == 0)
@@ -301,6 +334,12 @@
        if (--med->med_host->mp_refcount == 0)  
                mach_port_put(med->med_host);  
 
+       /*
+        * Exceptions ports have been released when we
+        * released all the ports rights asociated with
+        * the process, so do not touch them now. 
+        */
+
        free(med, M_EMULDATA);
        p->p_emuldata = NULL;
 
diff -r a59873dfcb20 -r ed081126e78f sys/compat/mach/mach_exec.h
--- a/sys/compat/mach/mach_exec.h       Tue Nov 18 13:21:53 2003 +0000
+++ b/sys/compat/mach/mach_exec.h       Tue Nov 18 14:11:33 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mach_exec.h,v 1.21 2003/11/18 01:40:18 manu Exp $       */
+/*     $NetBSD: mach_exec.h,v 1.22 2003/11/18 14:11:33 manu Exp $       */
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -48,6 +48,7 @@
 
 
 struct mach_emuldata {
+       int med_inited;                 /* Is this structure initialized? */
        int med_thpri;                  /* Saved priority */
        LIST_HEAD(med_right, mach_right) med_right;
        struct lock med_rightlock;      /* process right list and lock */