diff --git a/lib/ff_syscall_wrapper.c b/lib/ff_syscall_wrapper.c
index 18b97b0e5..0c99d2f64 100644
--- a/lib/ff_syscall_wrapper.c
+++ b/lib/ff_syscall_wrapper.c
@@ -177,6 +177,31 @@
 
 /* ioctl define end */
 
+/* fcntl define start */
+
+#define LINUX_F_DUPFD           0
+#define LINUX_F_GETFD           1
+#define LINUX_F_SETFD           2
+#define LINUX_F_GETFL           3
+#define LINUX_F_SETFL           4
+#define LINUX_F_GETLK           5
+#define LINUX_F_SETLK           6
+#define LINUX_F_SETLKW          7
+#define LINUX_F_SETOWN          8
+#define LINUX_F_GETOWN          9
+#define LINUX_F_OFD_GETLK       36
+#define LINUX_F_OFD_SETLK       37
+#define LINUX_F_OFD_SETLKW      38
+
+#define LINUX_O_APPEND          0x400
+#define LINUX_O_NONBLOCK        0x800
+#define LINUX_O_ASYNC           0x2000
+#define LINUX_O_DIRECT          0x4000
+#define LINUX_O_NOATIME         0x40000
+#define LINUX_O_CLOEXEC         0x80000
+
+/* fcntl define end */
+
 /* af define start */
 
 #define LINUX_AF_INET6        10
@@ -246,6 +271,140 @@ struct linux_cmsghdr
 
 extern int sendit(struct thread *td, int s, struct msghdr *mp, int flags);
 
+/* convert linux argp to freebsd argp. */
+static inline int
+linux2freebsd_fcntl(int cmd, intptr_t *argp)
+{
+    switch(cmd) {
+        case LINUX_F_DUPFD:
+            return F_DUPFD;
+        case LINUX_F_GETFD:
+            return F_GETFD;
+        case LINUX_F_SETFD:
+            if (*argp & LINUX_O_CLOEXEC) {
+                //clear linux O_CLOEXEC, set freebsd O_CLOEXEC.
+                *argp &= ~LINUX_O_CLOEXEC;
+                *argp |= O_CLOEXEC;
+            }
+
+            return F_SETFD;
+        case LINUX_F_GETFL:
+            return F_GETFL;
+        case LINUX_F_SETFL:
+            if (*argp & LINUX_O_NONBLOCK) {
+                //clear linux O_NONBLOCK, set freebsd O_NONBLOCK.
+                *argp &= ~LINUX_O_NONBLOCK;
+                *argp |= O_NONBLOCK;
+            }
+
+            if (*argp & LINUX_O_APPEND) {
+                //clear linux O_APPEND, set freebsd O_APPEND.
+                *argp &= ~LINUX_O_APPEND;
+                *argp |= O_APPEND;
+            }
+
+            if (*argp & LINUX_O_ASYNC) {
+                //clear linux O_ASYNC, set freebsd O_ASYNC.
+                *argp &= ~LINUX_O_ASYNC;
+                *argp |= O_ASYNC;
+            }
+
+            if (*argp & LINUX_O_DIRECT) {
+                //clear linux O_DIRECT, set freebsd O_DIRECT.
+                *argp &= ~LINUX_O_DIRECT;
+                *argp |= O_DIRECT;
+            }
+
+            return F_SETFL;
+        case LINUX_F_GETLK:
+            return F_GETLK;
+        case LINUX_F_SETLK:
+            return F_SETLK;
+        case LINUX_F_SETLKW:
+            return F_SETLKW;
+        case LINUX_F_SETOWN:
+            return F_SETOWN;
+        case LINUX_F_GETOWN:
+            return F_GETOWN;
+        case LINUX_F_OFD_GETLK:
+            return F_OGETLK;
+        case LINUX_F_OFD_SETLK:
+            return F_OSETLK;
+        case LINUX_F_OFD_SETLKW:
+            return F_OSETLKW;
+        default:
+            return cmd;
+    }
+}
+
+/*
+ * convert freebsd flags to linux flags.
+ * cmd has been converted to freebsd mode.
+ */
+static inline int
+freebsd2linux_fcntl(int cmd, int flags)
+{
+    switch(cmd) {
+        case F_DUPFD:
+            return flags;
+        case F_GETFD:
+            if (flags & O_CLOEXEC) {
+                //clear freebsd O_DIRECT, set linux O_DIRECT.
+                flags &= ~O_CLOEXEC;
+                flags |= LINUX_O_CLOEXEC;
+            }
+            return flags;
+        case F_SETFD:
+            return flags;
+        case F_GETFL:
+            if (flags & O_NONBLOCK) {
+                //clear linux O_NONBLOCK, set freebsd O_NONBLOCK.
+                flags &= ~O_NONBLOCK;
+                flags |= LINUX_O_NONBLOCK;
+            }
+
+            if (flags & O_APPEND) {
+                //clear linux O_APPEND, set freebsd O_APPEND.
+                flags &= ~O_APPEND;
+                flags |= LINUX_O_APPEND;
+            }
+
+            if (flags & O_ASYNC) {
+                //clear linux O_ASYNC, set freebsd O_ASYNC.
+                flags &= ~O_ASYNC;
+                flags |= LINUX_O_ASYNC;
+            }
+
+            if (flags & O_DIRECT) {
+                //clear linux O_DIRECT, set freebsd O_DIRECT.
+                flags &= ~O_DIRECT;
+                flags |= LINUX_O_DIRECT;
+            }
+
+            return flags;
+        case LINUX_F_SETFL:
+            return flags;
+        case F_GETLK:
+            return flags;
+        case F_SETLK:
+            return flags;
+        case F_SETLKW:
+            return flags;
+        case F_SETOWN:
+            return flags;
+        case F_GETOWN:
+            return flags;
+        case F_OGETLK:
+            return flags;
+        case F_OSETLK:
+            return flags;
+        case F_OSETLKW:
+            return flags;
+        default:
+            return flags;
+    }
+}
+
 static long
 linux2freebsd_ioctl(unsigned long request)
 {
@@ -1150,9 +1309,11 @@ ff_fcntl(int fd, int cmd, ...)
     argp = va_arg(ap, uintptr_t);
     va_end(ap);
 
+    cmd = linux2freebsd_fcntl(cmd, &argp);
+
     if ((rc = kern_fcntl(curthread, fd, cmd, argp)))
         goto kern_fail;
-    rc = curthread->td_retval[0];
+    rc = freebsd2linux_fcntl(cmd, curthread->td_retval[0]);
     return (rc);
 kern_fail:
     ff_os_errno(rc);