Re: [PATCH] Fix application of sizeof to pointer

From: Andrii Nakryiko
Date: Wed Oct 20 2021 - 13:55:42 EST


On Tue, Oct 12, 2021 at 4:17 AM <davidcomponentone@xxxxxxxxx> wrote:
>
> From: David Yang <davidcomponentone@xxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Signed-off-by: David Yang <davidcomponentone@xxxxxxxxx>
> ---

For future submissions, please use [PATCH bpf-next] subject prefix.
For changes that are targeted against BPF samples, please use
samples/bpf: prefix as well. So in this case the patch subject should
have been something like:

[PATCH bpf-next] samples/bpf: Fix application of sizeof to pointer

I've fixed it up and applied to bpf-next, thanks.

> samples/bpf/xdp_redirect_cpu_user.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c
> index 6e25fba64c72..d84e6949007c 100644
> --- 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) {
> --
> 2.30.2
>