From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Andrii Nakryiko <andriin@fb.com>,
Magnus Karlsson <magnus.karlsson@intel.com>,
Song Liu <songliubraving@fb.com>,
Alexei Starovoitov <ast@kernel.org>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 5.2 042/123] libbpf: silence GCC8 warning about string truncation
Date: Tue, 13 Aug 2019 22:09:26 -0400 [thread overview]
Message-ID: <20190814021047.14828-42-sashal@kernel.org> (raw)
In-Reply-To: <20190814021047.14828-1-sashal@kernel.org>
From: Andrii Nakryiko <andriin@fb.com>
[ Upstream commit cb8ffde5694ae5fffb456eae932aac442aa3a207 ]
Despite a proper NULL-termination after strncpy(..., ..., IFNAMSIZ - 1),
GCC8 still complains about *expected* string truncation:
xsk.c:330:2: error: 'strncpy' output may be truncated copying 15 bytes
from a string of length 15 [-Werror=stringop-truncation]
strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
This patch gets rid of the issue altogether by using memcpy instead.
There is no performance regression, as strncpy will still copy and fill
all of the bytes anyway.
v1->v2:
- rebase against bpf tree.
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/lib/bpf/xsk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index 8e03b65830da0..fa948c5445ecf 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -336,7 +336,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk)
return -errno;
ifr.ifr_data = (void *)&channels;
- strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
+ memcpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
ifr.ifr_name[IFNAMSIZ - 1] = '\0';
err = ioctl(fd, SIOCETHTOOL, &ifr);
if (err && errno != EOPNOTSUPP) {
@@ -561,7 +561,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
err = -errno;
goto out_socket;
}
- strncpy(xsk->ifname, ifname, IFNAMSIZ - 1);
+ memcpy(xsk->ifname, ifname, IFNAMSIZ - 1);
xsk->ifname[IFNAMSIZ - 1] = '\0';
err = xsk_set_xdp_socket_config(&xsk->config, usr_config);
--
2.20.1
prev parent reply other threads:[~2019-08-14 2:12 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190814021047.14828-1-sashal@kernel.org>
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 020/123] libbpf: sanitize VAR to conservative 1-byte INT Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 025/123] bpf: sockmap, sock_map_delete needs to use xchg Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 026/123] bpf: sockmap, synchronize_rcu before free'ing map Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 027/123] bpf: sockmap, only create entry if ulp is not already enabled Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 028/123] selftests/bpf: fix sendmsg6_prog on s390 Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 034/123] bpf: fix access to skb_shared_info->gso_segs Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 035/123] selftests/bpf: add another gso_segs access Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 036/123] libbpf: fix using uninitialized ioctl results Sasha Levin
2019-08-14 2:09 ` Sasha Levin [this message]
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