1 files changed, 39 insertions, 0 deletions
diff --git a/bsd-user/freebsd/os-proc.h b/bsd-user/freebsd/os-proc.h
index 7b2e6a9f79..0a3cd0ef57 100644
--- a/bsd-user/freebsd/os-proc.h
+++ b/bsd-user/freebsd/os-proc.h
@@ -219,4 +219,43 @@ static inline abi_long do_freebsd_vfork(void *cpu_env)
     return do_freebsd_fork(cpu_env);
 }
 
+/* rfork(2) */
+static inline abi_long do_freebsd_rfork(void *cpu_env, abi_long flags)
+{
+    abi_long ret;
+    abi_ulong child_flag;
+
+    /*
+     * XXX We need to handle RFMEM here, as well.  Neither are safe to execute
+     * as-is on x86 hosts because they'll split memory but not the stack,
+     * wreaking havoc on host architectures that use the stack to store the
+     * return address as both threads try to pop it off.  Rejecting RFSPAWN
+     * entirely for now is ok, the only consumer at the moment is posix_spawn
+     * and it will fall back to classic vfork(2) if we return EINVAL.
+     */
+    if ((flags & TARGET_RFSPAWN) != 0) {
+        return -TARGET_EINVAL;
+    }
+    fork_start();
+    ret = rfork(flags);
+    if (ret == 0) {
+        /* child */
+        child_flag = 1;
+        target_cpu_clone_regs(cpu_env, 0);
+    } else {
+        /* parent */
+        child_flag = 0;
+    }
+
+    /*
+     * The fork system call sets a child flag in the second return
+     * value: 0 for parent process, 1 for child process.
+     */
+    set_second_rval(cpu_env, child_flag);
+    fork_end(child_flag);
+
+    return ret;
+
+}
+
 #endif /* BSD_USER_FREEBSD_OS_PROC_H */