From: Jeremy Cline <jcline@redhat.com>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jesper Dangaard Brouer <hawk@kernel.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org, Jeremy Cline <jcline@redhat.com>
Subject: [PATCH] libbpf: Initialize *nl_pid so gcc 10 is happy
Date: Sat, 4 Apr 2020 01:14:30 -0400 [thread overview]
Message-ID: <20200404051430.698058-1-jcline@redhat.com> (raw)
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
next reply other threads:[~2020-04-04 5:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-04 5:14 Jeremy Cline [this message]
2020-04-06 2:46 ` [PATCH] libbpf: Initialize *nl_pid so gcc 10 is happy Andrii Nakryiko
2020-04-06 20:14 ` Daniel Borkmann
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