From: Jeremy Cline jcline@redhat.com
[ 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@redhat.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Andrii Nakryiko andriin@fb.com Link: https://lore.kernel.org/bpf/20200404051430.698058-1-jcline@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 6d47345a310bd..b294e2aeb3283 100644 --- a/tools/lib/bpf/netlink.c +++ b/tools/lib/bpf/netlink.c @@ -141,7 +141,7 @@ 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) @@ -256,7 +256,7 @@ int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info, { struct xdp_id_md xdp_id = {}; int sock, ret; - __u32 nl_pid; + __u32 nl_pid = 0; __u32 mask;
if (flags & ~XDP_FLAGS_MASK || !info_size)