diff -ruN kozos35/kozos.h kozos36/kozos.h
--- kozos35/kozos.h	Mon Jan 19 21:49:32 2009
+++ kozos36/kozos.h	Thu Jan 22 00:06:54 2009
@@ -5,6 +5,7 @@
 
 typedef int (*kz_func)(int argc, char *argv[]);
 typedef void (*kz_handler)(int signo);
+typedef void (*kz_prefunc)(int id);
 
 /* syscall */
 int kz_run(kz_func func, char *name, int pri, int argc, char *argv[]);
@@ -17,8 +18,9 @@
 int kz_send(int id, int size, char *p);
 int kz_recv(int *idp, char **pp);
 int kz_pending();
-int kz_sethandler(int signo, kz_handler handler);
 int kz_setsig(int signo);
+int kz_sethandler(int signo, kz_handler handler);
+int kz_precall(int id, kz_prefunc func);
 int kz_debug(int sockt);
 void *kz_kmalloc(int size);
 int kz_kmfree(void *p);
diff -ruN kozos35/syscall.c kozos36/syscall.c
--- kozos35/syscall.c	Mon Jan 19 21:45:20 2009
+++ kozos36/syscall.c	Thu Jan 22 00:06:52 2009
@@ -113,6 +113,15 @@
   return param.un.sethandler.ret;
 }
 
+int kz_precall(int id, kz_prefunc func)
+{
+  kz_syscall_param_t param;
+  param.un.precall.id = id;
+  param.un.precall.func = func;
+  kz_syscall(KZ_SYSCALL_TYPE_PRECALL, &param);
+  return param.un.precall.ret;
+}
+
 int kz_debug(int sockt)
 {
   kz_syscall_param_t param;
diff -ruN kozos35/syscall.h kozos36/syscall.h
--- kozos35/syscall.h	Mon Jan 19 21:45:15 2009
+++ kozos36/syscall.h	Thu Jan 22 00:05:14 2009
@@ -16,6 +16,7 @@
   KZ_SYSCALL_TYPE_PENDING,
   KZ_SYSCALL_TYPE_SETSIG,
   KZ_SYSCALL_TYPE_SETHANDLER,
+  KZ_SYSCALL_TYPE_PRECALL,
   KZ_SYSCALL_TYPE_DEBUG,
   KZ_SYSCALL_TYPE_KMALLOC,
   KZ_SYSCALL_TYPE_KMFREE,
@@ -76,6 +77,11 @@
       kz_handler handler;
       int ret;
     } sethandler;
+    struct {
+      int id;
+      kz_prefunc func;
+      int ret;
+    } precall;
     struct {
       int sockt;
       int ret;
diff -ruN kozos35/thread.c kozos36/thread.c
--- kozos35/thread.c	Mon Jan 19 21:47:33 2009
+++ kozos36/thread.c	Thu Jan 22 01:27:32 2009
@@ -287,6 +287,14 @@
     sendmsg(sigcalls[signo], 0, 0, NULL);
 }
 
+static int thread_precall(int id, kz_prefunc func)
+{
+  kz_thread *thp = (kz_thread *)id;
+  thp->precall = func;
+  putcurrent();
+  return 0;
+}
+
 static int thread_debug(int sockt)
 {
   debug_sockt = sockt;
@@ -366,6 +374,9 @@
     p->un.sethandler.ret = thread_sethandler(p->un.sethandler.signo,
 					     p->un.sethandler.handler);
     break;
+  case KZ_SYSCALL_TYPE_PRECALL:
+    p->un.precall.ret = thread_precall(p->un.precall.id, p->un.precall.func);
+    break;
   case KZ_SYSCALL_TYPE_DEBUG:
     p->un.debug.ret = thread_debug(p->un.debug.sockt);
     break;
@@ -455,6 +466,10 @@
   }
 
   schedule();
+
+  if (current->precall) {
+    current->precall((int)current);
+  }
 
   /*
    * スタブでの read() 待ちブロック中に SIGALRM (および SIGHUP)が発生した
diff -ruN kozos35/thread.h kozos36/thread.h
--- kozos35/thread.h	Mon Jan 19 01:03:05 2009
+++ kozos36/thread.h	Thu Jan 22 00:13:19 2009
@@ -29,6 +29,8 @@
   unsigned int flags;
 #define KZ_THREAD_FLAG_RUNNING (1 << 0)
 
+  kz_prefunc precall;
+
   struct {
     kz_syscall_type_t type;
     kz_syscall_param_t *param;