The commit 7e040726850a ("eventpoll.h: add missing epoll event masks") was backported to a couple of older kernels - including 4.4. The build against such kernel sources creates a lot of extra warnings about redefinitions of the different EPOLL* variables. Just disable the definition of these variables when they are already defined and drop the ones which are not used by batman-adv. Reported-by: Andre Kasper &lt;andre.kasper(a)gmx.de&gt; Signed-off-by: Sven Eckelmann &lt;sven(a)narfation.org&gt; --- Cc: Andre Kasper &lt;andre.kasper(a)gmx.de&gt; --- compat-include/uapi/linux/eventpoll.h | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/compat-include/uapi/linux/eventpoll.h b/compat-include/uapi/linux/eventpoll.h index 1828feb4..3cf71a19 100644 --- a/compat-include/uapi/linux/eventpoll.h +++ b/compat-include/uapi/linux/eventpoll.h @@ -28,18 +28,13 @@ #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 12, 0) +#ifndef EPOLLIN #define EPOLLIN (__force __poll_t)0x00000001 -#define EPOLLPRI (__force __poll_t)0x00000002 -#define EPOLLOUT (__force __poll_t)0x00000004 -#define EPOLLERR (__force __poll_t)0x00000008 -#define EPOLLHUP (__force __poll_t)0x00000010 -#define EPOLLNVAL (__force __poll_t)0x00000020 +#endif + +#ifndef EPOLLRDNORM #define EPOLLRDNORM (__force __poll_t)0x00000040 -#define EPOLLRDBAND (__force __poll_t)0x00000080 -#define EPOLLWRNORM (__force __poll_t)0x00000100 -#define EPOLLWRBAND (__force __poll_t)0x00000200 -#define EPOLLMSG (__force __poll_t)0x00000400 -#define EPOLLRDHUP (__force __poll_t)0x00002000 +#endif #endif /* < KERNEL_VERSION(4, 12, 0) */ -- 2.18.0