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KFunc bpf_refcount_acquire_impl

v6.4

Increment the refcount on a refcounted local kptr, turning the non-owning reference input into an owning reference in the process.

Definition

The meta parameter is rewritten by the verifier, no need for BPF program to set it.

Returns

An owning reference to the object pointed to by kptr

void *bpf_refcount_acquire_impl(void *p__refcounted_kptr, void *meta__ign)

Note

This kfunc returns a pointer to a refcounted object. The verifier will then ensure that the pointer to the object is eventually released using a release kfunc, or transferred to a map using a referenced kptr (by invoking bpf_kptr_xchg). If not, the verifier fails the loading of the BPF program until no lingering references remain in all possible explored states of the program.

Note

The pointer returned by the kfunc may be NULL. Hence, it forces the user to do a NULL check on the pointer returned from the kfunc before making use of it (dereferencing or passing to another helper).

Usage

Docs could be improved

This part of the docs is incomplete, contributions are very welcome

Program types

The following program types can make use of this kfunc:

Example

Docs could be improved

This part of the docs is incomplete, contributions are very welcome