The RingBuf caches the last value it read of the producer so it doesn't
need to constantly contend on the actual producer cache line if lots of
messages have yet to be consumed. It was bogus to initialize this cache
at 0. This patch initializes it properly and adds testing.
Fixes: #1309
This commit extends the EbpfLoader with set_map_pin_path that allows the
caller to associate a named map with a pin path.
One note is that this path is an absolute path, not relative to
`map_pin_path`, and it forces the map to be loaded from that path.
This is the path in which pinned maps are created or resolved. It
isn't actually the path for any specific map itself. This rename
makes way for a method `set_map_pin_path` that actually specifies
the pin path for a specific map.
I ran the below command and these changes popped out:
```bash
CARGO_CFG_BPF_TARGET_ARCH=x86_64 cargo +nightly xtask public-api --bless --target x86_64-unknown-linux-gnu
```
Recent changes[0][1] have broken compatibility with macOS; add a patch
to conditionally compile these snippets.
Patch and compile the source unconditionally; caching only the network
portion is good enough and less error prone.
[0] ae18b94099
[1] 97169cd6d9
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>
eBPF verifier in recent kernels should be smart enough to track map
map types and catch invalid pointer casts. Rust type system makes sure
that the `get` method can return only the same type the map was created
with. Therefore, safe usage of Aya map types shouldn't cause element
type mismatches.
Manual alignment checks (`pointer::is_aligned` or manual pointer
arithmetic operations) cause the following verifier error:
```
bitwise operator &= on pointer prohibited
```
And it extremely unlikely `bpf_map_lookup_elem` ever returns a
misaligned pointer.
`bpf_map_def` is a legacy map definition. To be able to introduce BTF
map definitions, make the `lookup` and `remove` helpers work with
`c_void` and let the callers cast the map types to it.
Enables creation of Map enum variants directly from MapData instances,
allowing user-space handles to pinned BPF maps without requiring the
original BPF object.
Supports multiple BPF map types.
Motivation:
- Simplifies accessing pinned maps from user space applications.
- Avoids full BPF reloads and potential deadlocks.
- Matches existing ergonomic APIs like LruHashMap::try_from.
- Keeps user code safe and idiomatic.
Closes https://github.com/aya-rs/aya/issues/1305.
Includes test coverage to validate the new API.
The log level implementation in b36cbc3eb8
was incomplete as the verifier could reject programs which exceeded
their instruction limits within logging statements. This commit
addresses this issue by making the log level static variable immutable
(s.t. the compiler puts it in a read-only section) and adds an
additional test which the verifier will reject as an infinite loop iff
it is unable to detect that the static variable would otherwise allow
the logging.
Andrew Werner
Tamir Duberstein
dependabot[bot]
Thomas Eizinger
tamird
Michal R
Adam Schreck
Xiaobo Liu
Addison Crump