On Mon, Jul 31, 2023 at 11:15 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> On Mon, Jul 31, 2023 at 01:47:01PM -0700, Alexei Starovoitov wrote:
> > Probably the following will be enough:
> > diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> > index 56ce5008aedd..eb91cae0612a 100644
> > --- a/kernel/bpf/helpers.c
> > +++ b/kernel/bpf/helpers.c
> > @@ -2270,7 +2270,7 @@ __bpf_kfunc void *bpf_dynptr_slice(const struct
> > bpf_dynptr_kern *ptr, u32 offset
> > case BPF_DYNPTR_TYPE_XDP:
> > {
> > void *xdp_ptr = bpf_xdp_pointer(ptr->data, ptr->offset
> > + offset, len);
> > - if (xdp_ptr)
> > + if (!IS_ERR_OR_NULL(xdp_ptr))
> > return xdp_ptr;
>
> Also please, add a comment to bpf_xdp_pointer() which explains what the
> NULL return means. I couldn't figure it out.
>
> >
> > Also I've noticed:
> > void bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned long off,
> > void *buf, unsigned long len, bool flush);
> > #else /* CONFIG_NET */
> > static inline void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset, u32 len)
> > {
> > return NULL;
> > }
> >
> > The latter is wrong.
>
> This the only part which I thought I understood. :P How is this wrong?
copy-paste mistake.
I meant:
static inline void *bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned
long off, void *buf,
unsigned long len, bool flush)
{
return NULL;
}
is wrong.
