[PATCH 1/2] Prepare to trace fork series calls using PTRACE_SETOPTIONS

[Wang Chao]

* defs.h: Add new function declaration.
* process.c (reparent): Move code which handle parent relationship
  of new child process to a new function.
  (internal_fork): Call it.

Signed-off-by: Wang Chao <wang.chao at cn.fujitsu.com>
---
 defs.h    |    3 ++
 process.c |   79 +++++++++++++++++++++++++++++++-----------------------------
 2 files changed, 44 insertions(+), 38 deletions(-)

diff --git a/defs.h b/defs.h
index 4b9c29e..a813f5b 100644
--- a/defs.h
+++ b/defs.h
@@ -545,6 +545,9 @@ extern int internal_fork(struct tcb *);
 extern int internal_exec(struct tcb *);
 extern int internal_wait(struct tcb *, int);
 extern int internal_exit(struct tcb *);
+#ifdef LINUX
+extern void reparent(struct tcb *, struct tcb *);
+#endif
 
 extern const struct ioctlent *ioctl_lookup(long);
 extern const struct ioctlent *ioctl_next_match(const struct ioctlent *);
diff --git a/process.c b/process.c
index f7af196..7f9353a 100644
--- a/process.c
+++ b/process.c
@@ -790,6 +790,46 @@ change_syscall(struct tcb *tcp, int new)
 }
 
 #ifdef LINUX
+void reparent(struct tcb *tcp, struct tcb *tcpchild)
+{
+	/*
+	 * Save the flags used in this call,
+	 * in case we point TCP to our parent below.
+	 */
+	int call_flags = tcp->u_arg[ARG_FLAGS];
+	if ((tcp->flags & TCB_CLONE_THREAD) &&
+	    tcp->parent != NULL) {
+		/* The parent in this clone is itself a
+		   thread belonging to another process.
+		   There is no meaning to the parentage
+		   relationship of the new child with the
+		   thread, only with the process.  We
+		   associate the new thread with our
+		   parent.  Since this is done for every
+		   new thread, there will never be a
+		   TCB_CLONE_THREAD process that has
+		   children.  */
+		--tcp->nchildren;
+		tcp = tcp->parent;
+		tcpchild->parent = tcp;
+		++tcp->nchildren;
+	}
+	if (call_flags & CLONE_THREAD) {
+		tcpchild->flags |= TCB_CLONE_THREAD;
+		++tcp->nclone_threads;
+	}
+	if ((call_flags & CLONE_PARENT) &&
+	    !(call_flags & CLONE_THREAD)) {
+		--tcp->nchildren;
+		tcpchild->parent = NULL;
+		if (tcp->parent != NULL) {
+			tcp = tcp->parent;
+			tcpchild->parent = tcp;
+			++tcp->nchildren;
+		}
+	}
+}
+
 int
 internal_fork(struct tcb *tcp)
 {
@@ -882,44 +922,7 @@ Process %u resumed (parent %d ready)\n",
 		}
 
 #ifdef TCB_CLONE_THREAD
-		{
-			/*
-			 * Save the flags used in this call,
-			 * in case we point TCP to our parent below.
-			 */
-			int call_flags = tcp->u_arg[ARG_FLAGS];
-			if ((tcp->flags & TCB_CLONE_THREAD) &&
-			    tcp->parent != NULL) {
-				/* The parent in this clone is itself a
-				   thread belonging to another process.
-				   There is no meaning to the parentage
-				   relationship of the new child with the
-				   thread, only with the process.  We
-				   associate the new thread with our
-				   parent.  Since this is done for every
-				   new thread, there will never be a
-				   TCB_CLONE_THREAD process that has
-				   children.  */
-				--tcp->nchildren;
-				tcp = tcp->parent;
-				tcpchild->parent = tcp;
-				++tcp->nchildren;
-			}
-			if (call_flags & CLONE_THREAD) {
-				tcpchild->flags |= TCB_CLONE_THREAD;
-				++tcp->nclone_threads;
-			}
-			if ((call_flags & CLONE_PARENT) &&
-			    !(call_flags & CLONE_THREAD)) {
-				--tcp->nchildren;
-				tcpchild->parent = NULL;
-				if (tcp->parent != NULL) {
-					tcp = tcp->parent;
-					tcpchild->parent = tcp;
-					++tcp->nchildren;
-				}
-			}
-		}
+		reparent(tcp, tcpchild);
 #endif /* TCB_CLONE_THREAD */
 	}
 	return 0;
-- 
1.6.5.2