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aya/aya-obj
Friday Ortiz ab38afe95d
perf_event: support hardware breakpoints
Implement `PerfEventConfig::Breakpoint`, allowing users to attach
hardware breakpoints. Generate `HW_BREAKPOINT_*` and `struct
bpf_perf_event_data` in support of this feature and update the type of
`PerfEventContext` accordingly.

Add a test exercising R, W, RW, and X breakpoints. Note that R
breakpoints are unsupported on x86, and this is asserted in the test.

Extend the VM integration test harness and supporting infrastructure
(e.g. `download_kernel_images.sh`) to download kernel debug packages and
mount `System.map` in initramfs. This is needed (at least) on the aarch
6.1 Debian kernel which was not compiled with `CONFIG_KALLSYMS_ALL=y`
for some reason, and the locations of globals are not available in
kallsyms. To attach breakpoints to these symbols in the test pipeline,
we need to read them from System.map and apply the KASLR offset to get
their real address. The `System.map` file is not provided in the kernel
package by default, so we need to extract it from the corresponding
debug package. The KASLR offset is computed using `gunzip` which appears
in kallsyms on all Debian kernels tested.

Co-authored-by: Tamir Duberstein <tamird@gmail.com>
7 days ago
..
include perf_event: support hardware breakpoints 7 days ago
src perf_event: support hardware breakpoints 7 days ago
CHANGELOG.md Release aya-obj v0.2.1 1 year ago
Cargo.toml aya-obj: explicitly enable hashbrown features 2 months ago
README.md aya-obj: update documentation and versioning info 3 years ago

README.md

aya-obj

Status

This crate includes code that started as internal API used by the aya crate. It has been split out so that it can be used by other projects that deal with eBPF object files. Unless you're writing low level eBPF plumbing tools, you should not need to use this crate but see the aya crate instead.

The API as it is today has a few rough edges and is generally not as polished nor stable as the main aya crate API. As always, improvements welcome!

Overview

eBPF programs written with libbpf or aya-bpf are usually compiled into an ELF object file, using various sections to store information about the eBPF programs.

aya-obj is a library for parsing such eBPF object files, with BTF and relocation support.

Example

This example loads a simple eBPF program and runs it with rbpf.

use aya_obj::{generated::bpf_insn, Object};

// Parse the object file
let bytes = std::fs::read("program.o").unwrap();
let mut object = Object::parse(&bytes).unwrap();
// Relocate the programs
object.relocate_calls().unwrap();
object.relocate_maps(std::iter::empty()).unwrap();

// Run with rbpf
let instructions = &object.programs["prog_name"].function.instructions;
let data = unsafe {
    core::slice::from_raw_parts(
        instructions.as_ptr() as *const u8,
        instructions.len() * core::mem::size_of::<bpf_insn>(),
    )
};
let vm = rbpf::EbpfVmNoData::new(Some(data)).unwrap();
let _return = vm.execute_program().unwrap();