samples/bpf: Fix application of sizeof to pointer

The coccinelle check report:
"./samples/bpf/xdp_redirect_cpu_user.c:397:32-38:
ERROR: application of sizeof to pointer"
Using the "strlen" to fix it.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: David Yang <davidcomponentone@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211012111649.983253-1-davidcomponentone@gmail.com

diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c
index 6e25fba..d84e694 100644 (file)
--- a/samples/bpf/xdp_redirect_cpu_user.c
+++ b/samples/bpf/xdp_redirect_cpu_user.c
@@ -325,7 +325,6 @@ int main(int argc, char **argv)
        int add_cpu = -1;
        int ifindex = -1;
        int *cpu, i, opt;
-       char *ifname;
        __u32 qsize;
        int n_cpus;
 
@@ -393,9 +392,8 @@ int main(int argc, char **argv)
                                fprintf(stderr, "-d/--dev name too long\n");
                                goto end_cpu;
                        }
-                       ifname = (char *)&ifname_buf;
-                       safe_strncpy(ifname, optarg, sizeof(ifname));
-                       ifindex = if_nametoindex(ifname);
+                       safe_strncpy(ifname_buf, optarg, strlen(ifname_buf));
+                       ifindex = if_nametoindex(ifname_buf);
                        if (!ifindex)
                                ifindex = strtoul(optarg, NULL, 0);
                        if (!ifindex) {