libbpf: Initialize *nl_pid so gcc 10 is happy

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
This commit is contained in:
Jeremy Cline 2020-04-04 01:14:30 -04:00 committed by Daniel Borkmann
parent db5c97f023
commit 4734b0fefb

View File

@ -142,7 +142,7 @@ static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd,
struct ifinfomsg ifinfo;
char attrbuf[64];
} req;
__u32 nl_pid;
__u32 nl_pid = 0;
sock = libbpf_netlink_open(&nl_pid);
if (sock < 0)
@ -288,7 +288,7 @@ 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)