Re: [PATCH bpf-next v13 04/14] bpf: add struct_ops_tab to btf.

[Martin KaFai Lau <martin.lau@linux.dev>]

On 12/8/23 4:26 PM, thinker.li@gmail.com wrote:
> +const struct bpf_struct_ops_desc *btf_get_struct_ops(struct btf *btf, u32 *ret_cnt)
> +{
> +	if (!btf)
> +		return NULL;
> +	if (!btf->struct_ops_tab)

		*ret_cnt = 0;

unless the later patch checks the return value NULL before using *ret_cnt.
Anyway, better to set *ret_cnt to 0 if the btf has no struct_ops.

The same should go for the "!btf" case above but I suspect the above !btf check 
is unnecessary also and the caller should have checked for !btf itself instead 
of expecting a list of struct_ops from a NULL btf. Lets continue the review on 
the later patches for now to confirm where the above !btf case might happen.

> +		return NULL;
> +
> +	*ret_cnt = btf->struct_ops_tab->cnt;
> +	return (const struct bpf_struct_ops_desc *)btf->struct_ops_tab->ops;
> +}