commit c1ad4efe09abf7bd11fa38a5d74811f62b68b8e7
author Björn Töpel <bjorn.topel@intel.com> Mon May 06 11:24:43 2019 +0200
committer Andrii Nakryiko <andrii.nakryiko@gmail.com> Thu May 16 09:40:04 2019 -0700
tree c41560d538fb0c420f5cc8aa4e972388899d4e95
parent 65cfbbcc8714fc3ea43cd999a64b54ef14487c93

libbpf: remove unnecessary cast-to-void

The patches with fixes tags added a cast-to-void in the places when
the return value of a function was ignored.

This is not common practice in the kernel, and is therefore removed in
this patch.

Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Fixes: 5750902a6e9b ("libbpf: proper XSKMAP cleanup")
Fixes: 0e6741f09297 ("libbpf: fix invalid munmap call")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

src/xsk.c

diff --git a/src/xsk.c b/src/xsk.c
index 525f1cc..a3d1a30 100644
--- a/src/xsk.c
+++ b/src/xsk.c
@@ -459,8 +459,8 @@
 {
 	int qid = false;
 
-	(void)bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id, &qid, 0);
-	(void)bpf_map_delete_elem(xsk->xsks_map_fd, &xsk->queue_id);
+	bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id, &qid, 0);
+	bpf_map_delete_elem(xsk->xsks_map_fd, &xsk->queue_id);
 }
 
 static int xsk_set_bpf_maps(struct xsk_socket *xsk)
@@ -686,12 +686,10 @@
 	optlen = sizeof(off);
 	err = getsockopt(umem->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);
 	if (!err) {
-		(void)munmap(umem->fill->ring - off.fr.desc,
-			     off.fr.desc +
-			     umem->config.fill_size * sizeof(__u64));
-		(void)munmap(umem->comp->ring - off.cr.desc,
-			     off.cr.desc +
-			     umem->config.comp_size * sizeof(__u64));
+		munmap(umem->fill->ring - off.fr.desc,
+		       off.fr.desc + umem->config.fill_size * sizeof(__u64));
+		munmap(umem->comp->ring - off.cr.desc,
+		       off.cr.desc + umem->config.comp_size * sizeof(__u64));
 	}
 
 	close(umem->fd);
@@ -717,14 +715,12 @@
 	err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);
 	if (!err) {
 		if (xsk->rx) {
-			(void)munmap(xsk->rx->ring - off.rx.desc,
-				     off.rx.desc +
-				     xsk->config.rx_size * desc_sz);
+			munmap(xsk->rx->ring - off.rx.desc,
+			       off.rx.desc + xsk->config.rx_size * desc_sz);
 		}
 		if (xsk->tx) {
-			(void)munmap(xsk->tx->ring - off.tx.desc,
-				     off.tx.desc +
-				     xsk->config.tx_size * desc_sz);
+			munmap(xsk->tx->ring - off.tx.desc,
+			       off.tx.desc + xsk->config.tx_size * desc_sz);
 		}
 
 	}