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 b943e248eb983d2edb3a0b18e2baf171a89811ef..33b3894ad467e10ef743545929ee11a03cf8cdfb 100644 (file)
--- 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