aya: add multi-uprobe attach support

[swananan]

This PR tackles #992 and focuses on multi-attach uprobes.

Main talking points:

1. Refactors symbol resolution to batch lookups over a single object::File mmap, since repeated mmap/parse per location was too expensive for multi-attach workloads. I haven’t split out a dedicated symbol resolver yet because that felt heavier, but I’m open to doing this.

2. Introduces #[uprobe(multi)] expectations, add attach-type checks, and emit friendly ProgramNotMulti/UProbeMultiNotSupported errors. To keep compiled_for_multi in sync, UProbe can no longer rely on the shared impl_from_prog_info! macro, so it now hand-rolls from_program_info (open to suggestions for a more reusable pattern).

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[tamird]

@tamird reviewed 8 of 13 files at r1.
Reviewable status: 8 of 14 files reviewed, 3 unresolved discussions (waiting on @swananan)

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test/integration-test/src/tests/uprobe_multi.rs line 34 at r1 (raw file):

        Some(map) => map,
        None => {
            eprintln!("skipping test because RING_BUF map is unavailable");

how can this happen? if it can't, please fail the test on it.

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test/integration-ebpf/src/uprobe_multi.rs line 21 at r1 (raw file):

    let cookie = unsafe { helpers::bpf_get_attach_cookie(ctx.as_ptr()) };
    let cookie_bytes = cookie.to_le_bytes();
    let _ = RING_BUF.output::<[u8]>(cookie_bytes, 0);

let _res to match existing style plz

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aya/src/programs/uprobe.rs line 198 at r1 (raw file):

    ///   cookies; the list must be non-empty or the call fails with
    ///   [`UProbeError::InvalidLocations`].
    pub fn attach_multi(

does this need to be a separate function? The current attach already has an abstraction we can use (UProbeAttachLocation). We can change that type to allow it to model multiple attachment and implement conversion (From or Into) such that a user could pass a list to indicate multiple attachment. WDYT?

[swananan]

@tamird I used a separate attach_multi for two reasons. First, the uprobe multi lets every location carry its own cookie, I wanted the type system to enforce that one-to-one relationship instead of juggling parallel arrays. Bundling location + cookie into the existing attach signature felt like churn—people upgrading Aya would have to touch their code even if they never use uprobe multi. Second, having a dedicated entry point keeps the docs straightforward and makes it harder to miss details like “your eBPF program must use #[uprobe(multi)]”. Even with good error messages that requirement can be surprising.

That said, these are just instincts from a Rust newbie (I’ve been around Rust for a while now, but I still feel like a newbie 😂). Yeah, I’ve noticed the current attach_multi API isn’t very idiomatic Rust either.

If we go with a single attach interface, I’d prefer to bundle the location and cookie together so we keep that one-one relationship. If that approach sounds ok to you, I'm happy to refactor it.

[tamird]

Bundling the two makes sense to me. Perhaps that can happen in a standalone PR ahead of this one.