On Wed, 2026-03-11 at 16:46 -0700, Amery Hung wrote:

On Wed, Mar 11, 2026 at 3:30 PM Alexei Starovoitov
[off-list ref] wrote:

quoted

On Wed, Mar 11, 2026 at 3:26 PM Alexei Starovoitov
[off-list ref] wrote:

[...]

quoted

One more thing...

How does it interact with reg_is_init_pkt_pointer() ?

That pointer has to have id == 0.

I haven't looked deep into the case. Currently, skb is non-referenced
for non-qdisc programs, so skb dynptr won't need to track it.

If there is ever a need to track it, we can assign a reserved non-zero
id to the unmodified pkt pointer. For reg_is_init_pkt_pointer(), it is
already checking tnum_equals_const(reg->var_off, 0), so maybe it is
fine to drop the id check (not sure).

Looks like dropping id == 0 check in reg_is_init_pkt_pointer() should be fine.