Add a new `aya-common` crate with a `SpinLock` struct, that wraps
`bpf_spin_lock` and allows to use it in BPF maps.
Add an extension trait `EbpfSpinLock` that provides a `lock` method,
which is a wrapper over `bpf_spin_lock` helper. It returns a
`SpinLockGuard` that calls `bpf_spin_unlock` helper once dropped.
Test that functionality with a simple XDP counter program.
Before this change, Aya supported only legacy BPF map definitions, which
are instances of the `bpf_map_def` struct and end up in the `maps` ELF
section.
This change introduces a BTF map definition for arrays, with custom
structs indicating the metadata of the map, which end up in the `.maps`
section.
Co-authored-by: Tamir Duberstein <tamird@gmail.com>
Provide an `arg()` method in `RawTracepointArgs` wrapper of
`bpf_raw_tracepoint_args` and also in `RawTracepointContext`, so
it's directly available in raw tracepoint programs.
The methods and traits implemented here are unsafe. There is no
way to reliably check the number of available arguments, so
requesting a non-existing one leads to undefined behavior.
Michal R
Tamir Duberstein
Xiaobo Liu
Mike Rostecki