[RFC PATCH 10/11] bpf: add bpf_buffer_reserve and bpf_buffer_commit

Add two helpers that are primarily used in combination with the writable-buffer support. The bpf_buffer_reserve() helper sets aside a chunk of buffer space that can be written to, and once all data has been written, the bpf_buffer_commit() helper is used to make the data in the ring buffer visible

[RFC PATCH 10/11] bpf: add bpf_buffer_reserve and bpf_buffer_commit helpers

Add two helpers that are primarily used in combination with the writable-buffer support. The bpf_buffer_reserve() helper sets aside a chunk of buffer space that can be written to, and once all data has been written, the bpf_buffer_commit() helper is used to make the data in the ring buffer visible