Re: [PATCH bpf-next v5 07/14] bpf: Unify referenced object tracking in verifier

[Eduard Zingerman <eddyz87@gmail.com>]

On Tue, 2026-05-19 at 11:13 -0700, Amery Hung wrote:
> Helpers and kfuncs independently tracked referenced object metadata (id,
> ref_obj_id) using separate fields in their respective arg_meta structs.
> This led to duplicated logic and inconsistent error handling between the
> two paths.
> 
> Introduce struct ref_obj_desc to consolidate these fields along with a
> count of how many arguments carry a reference. Add update_ref_obj() to
> populate it from a bpf_reg_state, replacing open-coded assignments in
> check_func_arg(), check_kfunc_args(), and process_iter_arg(). Add
> validate_ref_obj() to check for ambiguous ref_obj before using it.
> 
> For ref_obj releasing helpers and kfuncs, keep checking it before
> calling update_ref_obj() for now. A later patch will make these
> functions not depending on ref_obj. For other users of ref_obj, move the
> checks to the use locations. For helper, this means moving the checks
> inside helper_multiple_ref_obj_use() to use locations.
> is_acquire_function() is dropped as ref_obj is never used.
> 
> Pass ref_obj_desc into process_dynptr_func()/mark_stack_slots_dynptr()
> instead of a bare parent_id to make it less confusing.
> 
> Drop the selftest introduced in 7ec899ac90a2 (“selftests/bpf: Negative
> test case for ref_obj_id in args”) since the verifier no longer
> complains about ambiguous ref_obj if it is not used.
> 
> Signed-off-by: Amery Hung <ameryhung@gmail.com>
> ---

Acked-by: Eduard Zingerman <eddyz87@gmail.com>

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