Re: [PATCH bpf-next v5 2/7] bpf: Refactor {acquire,release}_reference_state

[Eduard Zingerman <eddyz87@gmail.com>]

On Thu, 2024-11-28 at 16:16 -0800, Kumar Kartikeya Dwivedi wrote:
> In preparation for introducing support for more reference types which
> have to add and remove reference state, refactor the
> acquire_reference_state and release_reference_state functions to share
> common logic.
> 
> The acquire_reference_state function simply handles growing the acquired
> refs and returning the pointer to the new uninitialized element, which
> can be filled in by the caller.
> 
> The release_reference_state function simply erases a reference state
> entry in the acquired_refs array and shrinks it. The callers are
> responsible for finding the suitable element by matching on various
> fields of the reference state and requesting deletion through this
> function. It is not supposed to be called directly.
> 
> Existing callers of release_reference_state were using it to find and
> remove state for a given ref_obj_id without scrubbing the associated
> registers in the verifier state. Introduce release_reference_nomark to
> provide this functionality and convert callers. We now use this new
> release_reference_nomark function within release_reference as well.
> It needs to operate on a verifier state instead of taking verifier env
> as mark_ptr_or_null_regs requires operating on verifier state of the
> two branches of a NULL condition check, therefore env->cur_state cannot
> be used directly.
> 
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---

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

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