RE: [PATCH v3 bpf] trace: bpf: Fix passing zero to PTR_ERR()

From: John Fastabend
Date: Mon Nov 09 2020 - 16:18:14 EST


Wang Qing wrote:
> There is a bug when passing zero to PTR_ERR() and return.
> Fix smatch err.
>
> Signed-off-by: Wang Qing <wangqing@xxxxxxxx>
> ---
> kernel/trace/bpf_trace.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 4517c8b..5113fd4
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1198,7 +1198,7 @@ static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
> *btf = bpf_get_btf_vmlinux();
>
> if (IS_ERR_OR_NULL(*btf))
> - return PTR_ERR(*btf);
> + return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
>
> if (ptr->type_id > 0)
> *btf_id = ptr->type_id;
> --
> 2.7.4
>

Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>