1 files changed, 20 insertions, 0 deletions
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 00b49e90d05f..3a2a84ab9325 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -10,6 +10,8 @@
 #include <errno.h>
 #include <signal.h>
 #include <fcntl.h>
+#include <limits.h>
+#include <linux/futex.h>
 #include <sys/mman.h>
 #include <sys/ptrace.h>
 #include <sys/prctl.h>
@@ -189,3 +191,21 @@ void os_set_pdeathsig(void)
 {
 	prctl(PR_SET_PDEATHSIG, SIGKILL);
 }
+
+int os_futex_wait(void *uaddr, unsigned int val)
+{
+	int r;
+
+	CATCH_EINTR(r = syscall(__NR_futex, uaddr, FUTEX_WAIT, val,
+				NULL, NULL, 0));
+	return r < 0 ? -errno : r;
+}
+
+int os_futex_wake(void *uaddr)
+{
+	int r;
+
+	CATCH_EINTR(r = syscall(__NR_futex, uaddr, FUTEX_WAKE, INT_MAX,
+				NULL, NULL, 0));
+	return r < 0 ? -errno : r;
+}