From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 21 Feb 2012 15:55:55 +0000 (-0500)
Subject: Add freebsd rfork support
X-Git-Url: http://git.lttng.org/?p=lttng-ust.git;a=commitdiff_plain;h=619231f11293e78b6bfa81f0ae9789a87b50289e

Add freebsd rfork support

commit 939c89cb3cf490502503fb2c20d62b2087160bb5 upstream.

[ Edit by Christian Babeux: Resolve conflict around #ifdef linux
  and daemon() override. ]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Christian Babeux <christian.babeux@efficios.com>
---

diff --git a/liblttng-ust-fork/ustfork.c b/liblttng-ust-fork/ustfork.c
index b943e248..33b3894a 100644
--- a/liblttng-ust-fork/ustfork.c
+++ b/liblttng-ust-fork/ustfork.c
@@ -28,8 +28,6 @@
 
 #include <lttng/ust.h>
 
-struct user_desc;
-
 pid_t fork(void)
 {
 	static pid_t (*plibc_func)(void) = NULL;
@@ -84,6 +82,10 @@ int daemon(int nochdir, int noclose)
 	return retval;
 }
 
+#ifdef __linux__
+
+struct user_desc;
+
 struct ustfork_clone_info {
 	int (*fn)(void *);
 	void *arg;
@@ -145,3 +147,41 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
 	}
 	return retval;
 }
+
+#elif defined (__FreeBSD__)
+
+pid_t rfork(int flags)
+{
+	static pid_t (*plibc_func)(void) = NULL;
+	sigset_t sigset;
+	pid_t retval;
+
+	if (plibc_func == NULL) {
+		plibc_func = dlsym(RTLD_NEXT, "rfork");
+		if (plibc_func == NULL) {
+			fprintf(stderr, "libustfork: unable to find \"rfork\" symbol\n");
+			return -1;
+		}
+	}
+
+	ust_before_fork(&sigset);
+	/* Do the real rfork */
+	retval = plibc_func();
+	if (retval == 0) {
+		/* child */
+		ust_after_fork_child(&sigset);
+	} else {
+		ust_after_fork_parent(&sigset);
+	}
+	return retval;
+}
+
+/*
+ * On BSD, no need to override vfork, because it runs in the context of
+ * the parent, with parent waiting until execve or exit is executed in
+ * the child.
+ */
+
+#else
+#warning "Unknown OS. You might want to ensure that fork/clone/vfork/fork handling is complete."
+#endif