1 files changed, 9 insertions, 0 deletions

diff --git a/arch/um/sys-i386/sysdep/barrier.h b/arch/um/sys-i386/sysdep/barrier.h
new file mode 100644
index 000000000000..b58d52c5b2f4
--- /dev/null
+++ b/arch/um/sys-i386/sysdep/barrier.h
@@ -0,0 +1,9 @@
+#ifndef __SYSDEP_I386_BARRIER_H
+#define __SYSDEP_I386_BARRIER_H
+
+/* Copied from include/asm-i386 for use by userspace.  i386 has the option
+ * of using mfence, but I'm just using this, which works everywhere, for now.
+ */
+#define mb() asm volatile("lock; addl $0,0(%esp)")
+
+#endif