From: Jeremy Cline <jcline@xxxxxxxxxx> [ Upstream commit 4734b0fefbbf98f8c119eb8344efa19dac82cd2c ] Builds of Fedora's kernel-tools package started to fail with "may be used uninitialized" warnings for nl_pid in bpf_set_link_xdp_fd() and bpf_get_link_xdp_info() on the s390 architecture. Although libbpf_netlink_open() always returns a negative number when it does not set *nl_pid, the compiler does not determine this and thus believes the variable might be used uninitialized. Assuage gcc's fears by explicitly initializing nl_pid. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1807781 Signed-off-by: Jeremy Cline <jcline@xxxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Acked-by: Andrii Nakryiko <andriin@xxxxxx> Link: https://lore.kernel.org/bpf/20200404051430.698058-1-jcline@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/lib/bpf/netlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c index ce3ec81b71c01..88416be2bf994 100644 --- a/tools/lib/bpf/netlink.c +++ b/tools/lib/bpf/netlink.c @@ -137,7 +137,7 @@ int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) struct ifinfomsg ifinfo; char attrbuf[64]; } req; - __u32 nl_pid; + __u32 nl_pid = 0; sock = libbpf_netlink_open(&nl_pid); if (sock < 0) @@ -254,7 +254,7 @@ int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags) { struct xdp_id_md xdp_id = {}; int sock, ret; - __u32 nl_pid; + __u32 nl_pid = 0; __u32 mask; if (flags & ~XDP_FLAGS_MASK) -- 2.20.1
