On 8/26/24 6:13 PM, Amery Hung wrote:
When dropping a local kptr, any kptr stashed into it is supposed to be freed through bpf_obj_free_fields->__bpf_obj_drop_impl recursively. Add a test to make sure it happens. The test first stashes a referenced kptr to "struct task" into a local kptr and gets the reference count of the task. Then, it drops the local kptr and reads the reference count of the task again. Since bpf_obj_free_fields and __bpf_obj_drop_impl will go through the local kptr recursively during bpf_obj_drop, the dtor of the stashed task kptr should eventually be called. The second reference count should be one less than the first one.
Acked-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
