From: Jeremy Cline <[email protected]>

[ 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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
---
 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



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