From 6d23065901549562b69fc84f34279d4635e5e9f0 Mon Sep 17 00:00:00 2001

From: Jeremy Cline <jcline@redhat.com>

Date: Fri, 3 Apr 2020 21:25:00 -0400

Subject: [PATCH] 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>

---

 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 18b5319025e19..9a14694176de0 100644

--- a/tools/lib/bpf/netlink.c

+++ b/tools/lib/bpf/netlink.c

@@ -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)

-- 

2.26.0