mirror of https://github.com/aya-rs/aya
Merge branch 'aya-rs:main' into main
qjerome
2 years ago
committed by
GitHub
commit
4801058f22
@ -0,0 +1,28 @@
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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char _license[] SEC("license") = "GPL";
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__type(key, __u32);
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__type(value, __u64);
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__uint(max_entries, 2);
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} RESULTS SEC(".maps");
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static __u64
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inc_cb(void *map, __u32 *key, void *val,
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void *data)
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{
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__u64 *value = val;
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*value += 1;
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return 0;
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}
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SEC("uprobe/test_text_64_64_reloc")
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int test_text_64_64_reloc(struct pt_regs *ctx)
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{
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bpf_for_each_map_elem(&RESULTS, inc_cb, NULL, 0);
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return 0;
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}
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@ -0,0 +1,45 @@
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#![no_std]
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#![no_main]
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use core::hint;
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use aya_bpf::{
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macros::{map, uprobe},
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maps::Array,
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programs::ProbeContext,
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};
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#[map]
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static mut RESULTS: Array<u64> = Array::with_max_entries(3, 0);
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#[uprobe]
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pub fn test_64_32_call_relocs(_ctx: ProbeContext) {
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// this will link set_result and do a forward call
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set_result(0, hint::black_box(1));
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// set_result is already linked, this will just do the forward call
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set_result(1, hint::black_box(2));
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// this will link set_result_backward after set_result. Then will do a
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// backward call to set_result.
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set_result_backward(2, hint::black_box(3));
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}
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#[inline(never)]
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fn set_result(index: u32, value: u64) {
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unsafe {
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if let Some(v) = RESULTS.get_ptr_mut(index) {
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*v = value;
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}
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}
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}
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#[inline(never)]
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fn set_result_backward(index: u32, value: u64) {
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set_result(index, value);
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}
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#[panic_handler]
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fn panic(_info: &core::panic::PanicInfo) -> ! {
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unsafe { core::hint::unreachable_unchecked() }
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}
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@ -0,0 +1,313 @@
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use anyhow::{Context, Result};
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use std::{path::PathBuf, process::Command, thread::sleep, time::Duration};
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use tempfile::TempDir;
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use aya::{maps::Array, programs::TracePoint, BpfLoader, Btf, Endianness};
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use super::integration_test;
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// In the tests below we often use values like 0xAAAAAAAA or -0x7AAAAAAA. Those values have no
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// special meaning, they just have "nice" bit patterns that can be helpful while debugging.
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#[integration_test]
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fn relocate_field() {
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let test = RelocationTest {
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local_definition: r#"
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struct foo {
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__u8 a;
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__u8 b;
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__u8 c;
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__u8 d;
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};
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"#,
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target_btf: r#"
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struct foo {
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__u8 a;
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__u8 c;
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__u8 b;
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__u8 d;
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} s1;
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"#,
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relocation_code: r#"
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__u8 memory[] = {1, 2, 3, 4};
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struct foo *ptr = (struct foo *) &memory;
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value = __builtin_preserve_access_index(ptr->c);
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"#,
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}
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.build()
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.unwrap();
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assert_eq!(test.run().unwrap(), 2);
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assert_eq!(test.run_no_btf().unwrap(), 3);
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}
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#[integration_test]
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fn relocate_enum() {
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let test = RelocationTest {
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local_definition: r#"
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enum foo { D = 0xAAAAAAAA };
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"#,
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target_btf: r#"
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enum foo { D = 0xBBBBBBBB } e1;
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"#,
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relocation_code: r#"
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#define BPF_ENUMVAL_VALUE 1
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value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
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"#,
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}
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.build()
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.unwrap();
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assert_eq!(test.run().unwrap(), 0xBBBBBBBB);
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assert_eq!(test.run_no_btf().unwrap(), 0xAAAAAAAA);
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}
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#[integration_test]
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fn relocate_enum_signed() {
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let test = RelocationTest {
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local_definition: r#"
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enum foo { D = -0x7AAAAAAA };
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"#,
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target_btf: r#"
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enum foo { D = -0x7BBBBBBB } e1;
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"#,
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relocation_code: r#"
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#define BPF_ENUMVAL_VALUE 1
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value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
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"#,
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}
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.build()
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.unwrap();
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assert_eq!(test.run().unwrap() as i64, -0x7BBBBBBBi64);
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assert_eq!(test.run_no_btf().unwrap() as i64, -0x7AAAAAAAi64);
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}
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#[integration_test]
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fn relocate_enum64() {
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let test = RelocationTest {
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local_definition: r#"
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enum foo { D = 0xAAAAAAAABBBBBBBB };
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"#,
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target_btf: r#"
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enum foo { D = 0xCCCCCCCCDDDDDDDD } e1;
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"#,
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relocation_code: r#"
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#define BPF_ENUMVAL_VALUE 1
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value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
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"#,
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}
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.build()
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.unwrap();
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assert_eq!(test.run().unwrap(), 0xCCCCCCCCDDDDDDDD);
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assert_eq!(test.run_no_btf().unwrap(), 0xAAAAAAAABBBBBBBB);
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}
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#[integration_test]
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fn relocate_enum64_signed() {
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let test = RelocationTest {
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local_definition: r#"
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enum foo { D = -0xAAAAAAABBBBBBBB };
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"#,
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target_btf: r#"
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enum foo { D = -0xCCCCCCCDDDDDDDD } e1;
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"#,
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relocation_code: r#"
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#define BPF_ENUMVAL_VALUE 1
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value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
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"#,
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}
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.build()
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.unwrap();
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assert_eq!(test.run().unwrap() as i64, -0xCCCCCCCDDDDDDDDi64);
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assert_eq!(test.run_no_btf().unwrap() as i64, -0xAAAAAAABBBBBBBBi64);
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}
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#[integration_test]
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fn relocate_pointer() {
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let test = RelocationTest {
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local_definition: r#"
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struct foo {};
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struct bar { struct foo *f; };
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"#,
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target_btf: r#"
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struct foo {};
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struct bar { struct foo *f; };
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"#,
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relocation_code: r#"
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__u8 memory[] = {42, 0, 0, 0, 0, 0, 0, 0};
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struct bar* ptr = (struct bar *) &memory;
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value = (__u64) __builtin_preserve_access_index(ptr->f);
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"#,
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}
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.build()
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.unwrap();
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assert_eq!(test.run().unwrap(), 42);
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assert_eq!(test.run_no_btf().unwrap(), 42);
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}
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/// Utility code for running relocation tests:
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/// - Generates the eBPF program using probided local definition and relocation code
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/// - Generates the BTF from the target btf code
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struct RelocationTest {
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/// Data structure definition, local to the eBPF program and embedded in the eBPF bytecode
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local_definition: &'static str,
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/// Target data structure definition. What the vmlinux would actually contain.
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target_btf: &'static str,
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/// Code executed by the eBPF program to test the relocation.
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/// The format should be:
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// __u8 memory[] = { ... };
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// __u32 value = BPF_CORE_READ((struct foo *)&memory, ...);
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//
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// The generated code will be executed by attaching a tracepoint to sched_switch
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// and emitting `__u32 value` an a map. See the code template below for more details.
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relocation_code: &'static str,
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}
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impl RelocationTest {
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/// Build a RelocationTestRunner
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fn build(&self) -> Result<RelocationTestRunner> {
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Ok(RelocationTestRunner {
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ebpf: self.build_ebpf()?,
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btf: self.build_btf()?,
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})
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}
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/// - Generate the source eBPF filling a template
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/// - Compile it with clang
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fn build_ebpf(&self) -> Result<Vec<u8>> {
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let local_definition = self.local_definition;
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let relocation_code = self.relocation_code;
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let (_tmp_dir, compiled_file) = compile(&format!(
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r#"
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#include <linux/bpf.h>
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static long (*bpf_map_update_elem)(void *map, const void *key, const void *value, __u64 flags) = (void *) 2;
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{local_definition}
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struct {{
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int (*type)[BPF_MAP_TYPE_ARRAY];
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__u32 *key;
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__u64 *value;
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int (*max_entries)[1];
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}} output_map
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__attribute__((section(".maps"), used));
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__attribute__((section("tracepoint/bpf_prog"), used))
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int bpf_prog(void *ctx) {{
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__u32 key = 0;
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__u64 value = 0;
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{relocation_code}
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bpf_map_update_elem(&output_map, &key, &value, BPF_ANY);
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return 0;
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}}
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char _license[] __attribute__((section("license"), used)) = "GPL";
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"#
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))
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.context("Failed to compile eBPF program")?;
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let bytecode =
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std::fs::read(compiled_file).context("Error reading compiled eBPF program")?;
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Ok(bytecode)
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}
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/// - Generate the target BTF source with a mock main()
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/// - Compile it with clang
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/// - Extract the BTF with llvm-objcopy
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fn build_btf(&self) -> Result<Btf> {
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let target_btf = self.target_btf;
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let relocation_code = self.relocation_code;
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// BTF files can be generated and inspected with these commands:
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// $ clang -c -g -O2 -target bpf target.c
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// $ pahole --btf_encode_detached=target.btf -V target.o
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// $ bpftool btf dump file ./target.btf format c
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let (tmp_dir, compiled_file) = compile(&format!(
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r#"
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#include <linux/bpf.h>
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{target_btf}
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int main() {{
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__u64 value = 0;
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// This is needed to make sure to emit BTF for the defined types,
|
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// it could be dead code eliminated if we don't.
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{relocation_code};
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return value;
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}}
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"#
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))
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.context("Failed to compile BTF")?;
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Command::new("llvm-objcopy")
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.current_dir(tmp_dir.path())
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.args(["--dump-section", ".BTF=target.btf"])
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.arg(compiled_file)
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.status()
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.context("Failed to run llvm-objcopy")?
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.success()
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.then_some(())
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.context("Failed to extract BTF")?;
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let btf = Btf::parse_file(tmp_dir.path().join("target.btf"), Endianness::default())
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.context("Error parsing generated BTF")?;
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Ok(btf)
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}
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}
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|
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/// Compile an eBPF program and return the path of the compiled object.
|
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/// Also returns a TempDir handler, dropping it will clear the created dicretory.
|
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fn compile(source_code: &str) -> Result<(TempDir, PathBuf)> {
|
||||
let tmp_dir = tempfile::tempdir().context("Error making temp dir")?;
|
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let source = tmp_dir.path().join("source.c");
|
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std::fs::write(&source, source_code).context("Writing bpf program failed")?;
|
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Command::new("clang")
|
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.current_dir(&tmp_dir)
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.args(["-c", "-g", "-O2", "-target", "bpf"])
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.arg(&source)
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.status()
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.context("Failed to run clang")?
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||||
.success()
|
||||
.then_some(())
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.context("Failed to compile eBPF source")?;
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Ok((tmp_dir, source.with_extension("o")))
|
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}
|
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|
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struct RelocationTestRunner {
|
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ebpf: Vec<u8>,
|
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btf: Btf,
|
||||
}
|
||||
|
||||
impl RelocationTestRunner {
|
||||
/// Run test and return the output value
|
||||
fn run(&self) -> Result<u64> {
|
||||
self.run_internal(true).context("Error running with BTF")
|
||||
}
|
||||
|
||||
/// Run without loading btf
|
||||
fn run_no_btf(&self) -> Result<u64> {
|
||||
self.run_internal(false)
|
||||
.context("Error running without BTF")
|
||||
}
|
||||
|
||||
fn run_internal(&self, with_relocations: bool) -> Result<u64> {
|
||||
let mut loader = BpfLoader::new();
|
||||
if with_relocations {
|
||||
loader.btf(Some(&self.btf));
|
||||
} else {
|
||||
loader.btf(None);
|
||||
}
|
||||
let mut bpf = loader.load(&self.ebpf).context("Loading eBPF failed")?;
|
||||
let program: &mut TracePoint = bpf
|
||||
.program_mut("bpf_prog")
|
||||
.context("bpf_prog not found")?
|
||||
.try_into()
|
||||
.context("program not a tracepoint")?;
|
||||
program.load().context("Loading tracepoint failed")?;
|
||||
// Attach to sched_switch and wait some time to make sure it executed at least once
|
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program
|
||||
.attach("sched", "sched_switch")
|
||||
.context("attach failed")?;
|
||||
sleep(Duration::from_millis(1000));
|
||||
// To inspect the loaded eBPF bytecode, increse the timeout and run:
|
||||
// $ sudo bpftool prog dump xlated name bpf_prog
|
||||
|
||||
let output_map: Array<_, u64> = bpf.take_map("output_map").unwrap().try_into().unwrap();
|
||||
let key = 0;
|
||||
output_map.get(&key, 0).context("Getting key 0 failed")
|
||||
}
|
||||
}
|
||||
@ -1,313 +1,70 @@
|
||||
use anyhow::{Context, Result};
|
||||
use std::{path::PathBuf, process::Command, thread::sleep, time::Duration};
|
||||
use tempfile::TempDir;
|
||||
use std::{process::exit, time::Duration};
|
||||
|
||||
use aya::{maps::Array, programs::TracePoint, BpfLoader, Btf, Endianness};
|
||||
|
||||
use super::{integration_test, IntegrationTest};
|
||||
|
||||
// In the tests below we often use values like 0xAAAAAAAA or -0x7AAAAAAA. Those values have no
|
||||
// special meaning, they just have "nice" bit patterns that can be helpful while debugging.
|
||||
use aya::{
|
||||
include_bytes_aligned,
|
||||
programs::{ProgramError, UProbe},
|
||||
Bpf,
|
||||
};
|
||||
use integration_test_macros::integration_test;
|
||||
|
||||
#[integration_test]
|
||||
fn relocate_field() {
|
||||
let test = RelocationTest {
|
||||
local_definition: r#"
|
||||
struct foo {
|
||||
__u8 a;
|
||||
__u8 b;
|
||||
__u8 c;
|
||||
__u8 d;
|
||||
};
|
||||
"#,
|
||||
target_btf: r#"
|
||||
struct foo {
|
||||
__u8 a;
|
||||
__u8 c;
|
||||
__u8 b;
|
||||
__u8 d;
|
||||
} s1;
|
||||
"#,
|
||||
relocation_code: r#"
|
||||
__u8 memory[] = {1, 2, 3, 4};
|
||||
struct foo *ptr = (struct foo *) &memory;
|
||||
value = __builtin_preserve_access_index(ptr->c);
|
||||
"#,
|
||||
}
|
||||
.build()
|
||||
.unwrap();
|
||||
assert_eq!(test.run().unwrap(), 2);
|
||||
assert_eq!(test.run_no_btf().unwrap(), 3);
|
||||
fn relocations() {
|
||||
let bpf = load_and_attach(
|
||||
"test_64_32_call_relocs",
|
||||
include_bytes_aligned!("../../../../target/bpfel-unknown-none/release/relocations"),
|
||||
);
|
||||
|
||||
trigger_relocations_program();
|
||||
std::thread::sleep(Duration::from_millis(100));
|
||||
|
||||
let m = aya::maps::Array::<_, u64>::try_from(bpf.map("RESULTS").unwrap()).unwrap();
|
||||
assert_eq!(m.get(&0, 0).unwrap(), 1);
|
||||
assert_eq!(m.get(&1, 0).unwrap(), 2);
|
||||
assert_eq!(m.get(&2, 0).unwrap(), 3);
|
||||
}
|
||||
|
||||
#[integration_test]
|
||||
fn relocate_enum() {
|
||||
let test = RelocationTest {
|
||||
local_definition: r#"
|
||||
enum foo { D = 0xAAAAAAAA };
|
||||
"#,
|
||||
target_btf: r#"
|
||||
enum foo { D = 0xBBBBBBBB } e1;
|
||||
"#,
|
||||
relocation_code: r#"
|
||||
#define BPF_ENUMVAL_VALUE 1
|
||||
value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
|
||||
"#,
|
||||
}
|
||||
.build()
|
||||
.unwrap();
|
||||
assert_eq!(test.run().unwrap(), 0xBBBBBBBB);
|
||||
assert_eq!(test.run_no_btf().unwrap(), 0xAAAAAAAA);
|
||||
}
|
||||
fn text_64_64_reloc() {
|
||||
let mut bpf = load_and_attach(
|
||||
"test_text_64_64_reloc",
|
||||
include_bytes_aligned!("../../../../target/bpfel-unknown-none/release/text_64_64_reloc.o"),
|
||||
);
|
||||
|
||||
#[integration_test]
|
||||
fn relocate_enum_signed() {
|
||||
let test = RelocationTest {
|
||||
local_definition: r#"
|
||||
enum foo { D = -0x7AAAAAAA };
|
||||
"#,
|
||||
target_btf: r#"
|
||||
enum foo { D = -0x7BBBBBBB } e1;
|
||||
"#,
|
||||
relocation_code: r#"
|
||||
#define BPF_ENUMVAL_VALUE 1
|
||||
value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
|
||||
"#,
|
||||
}
|
||||
.build()
|
||||
.unwrap();
|
||||
assert_eq!(test.run().unwrap() as i64, -0x7BBBBBBBi64);
|
||||
assert_eq!(test.run_no_btf().unwrap() as i64, -0x7AAAAAAAi64);
|
||||
}
|
||||
let mut m = aya::maps::Array::<_, u64>::try_from(bpf.map_mut("RESULTS").unwrap()).unwrap();
|
||||
m.set(0, 1, 0).unwrap();
|
||||
m.set(1, 2, 0).unwrap();
|
||||
|
||||
#[integration_test]
|
||||
fn relocate_enum64() {
|
||||
let test = RelocationTest {
|
||||
local_definition: r#"
|
||||
enum foo { D = 0xAAAAAAAABBBBBBBB };
|
||||
"#,
|
||||
target_btf: r#"
|
||||
enum foo { D = 0xCCCCCCCCDDDDDDDD } e1;
|
||||
"#,
|
||||
relocation_code: r#"
|
||||
#define BPF_ENUMVAL_VALUE 1
|
||||
value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
|
||||
"#,
|
||||
}
|
||||
.build()
|
||||
.unwrap();
|
||||
assert_eq!(test.run().unwrap(), 0xCCCCCCCCDDDDDDDD);
|
||||
assert_eq!(test.run_no_btf().unwrap(), 0xAAAAAAAABBBBBBBB);
|
||||
}
|
||||
trigger_relocations_program();
|
||||
std::thread::sleep(Duration::from_millis(100));
|
||||
|
||||
#[integration_test]
|
||||
fn relocate_enum64_signed() {
|
||||
let test = RelocationTest {
|
||||
local_definition: r#"
|
||||
enum foo { D = -0xAAAAAAABBBBBBBB };
|
||||
"#,
|
||||
target_btf: r#"
|
||||
enum foo { D = -0xCCCCCCCDDDDDDDD } e1;
|
||||
"#,
|
||||
relocation_code: r#"
|
||||
#define BPF_ENUMVAL_VALUE 1
|
||||
value = __builtin_preserve_enum_value(*(typeof(enum foo) *)D, BPF_ENUMVAL_VALUE);
|
||||
"#,
|
||||
}
|
||||
.build()
|
||||
.unwrap();
|
||||
assert_eq!(test.run().unwrap() as i64, -0xCCCCCCCDDDDDDDDi64);
|
||||
assert_eq!(test.run_no_btf().unwrap() as i64, -0xAAAAAAABBBBBBBBi64);
|
||||
assert_eq!(m.get(&0, 0).unwrap(), 2);
|
||||
assert_eq!(m.get(&1, 0).unwrap(), 3);
|
||||
}
|
||||
|
||||
#[integration_test]
|
||||
fn relocate_pointer() {
|
||||
let test = RelocationTest {
|
||||
local_definition: r#"
|
||||
struct foo {};
|
||||
struct bar { struct foo *f; };
|
||||
"#,
|
||||
target_btf: r#"
|
||||
struct foo {};
|
||||
struct bar { struct foo *f; };
|
||||
"#,
|
||||
relocation_code: r#"
|
||||
__u8 memory[] = {42, 0, 0, 0, 0, 0, 0, 0};
|
||||
struct bar* ptr = (struct bar *) &memory;
|
||||
value = (__u64) __builtin_preserve_access_index(ptr->f);
|
||||
"#,
|
||||
}
|
||||
.build()
|
||||
fn load_and_attach(name: &str, bytes: &[u8]) -> Bpf {
|
||||
let mut bpf = Bpf::load(bytes).unwrap();
|
||||
|
||||
let prog: &mut UProbe = bpf.program_mut(name).unwrap().try_into().unwrap();
|
||||
if let Err(ProgramError::LoadError {
|
||||
io_error,
|
||||
verifier_log,
|
||||
}) = prog.load()
|
||||
{
|
||||
println!("Failed to load program `{name}`: {io_error}. Verifier log:\n{verifier_log:#}");
|
||||
exit(1);
|
||||
};
|
||||
|
||||
prog.attach(
|
||||
Some("trigger_relocations_program"),
|
||||
0,
|
||||
"/proc/self/exe",
|
||||
None,
|
||||
)
|
||||
.unwrap();
|
||||
assert_eq!(test.run().unwrap(), 42);
|
||||
assert_eq!(test.run_no_btf().unwrap(), 42);
|
||||
}
|
||||
|
||||
/// Utility code for running relocation tests:
|
||||
/// - Generates the eBPF program using probided local definition and relocation code
|
||||
/// - Generates the BTF from the target btf code
|
||||
struct RelocationTest {
|
||||
/// Data structure definition, local to the eBPF program and embedded in the eBPF bytecode
|
||||
local_definition: &'static str,
|
||||
/// Target data structure definition. What the vmlinux would actually contain.
|
||||
target_btf: &'static str,
|
||||
/// Code executed by the eBPF program to test the relocation.
|
||||
/// The format should be:
|
||||
// __u8 memory[] = { ... };
|
||||
// __u32 value = BPF_CORE_READ((struct foo *)&memory, ...);
|
||||
//
|
||||
// The generated code will be executed by attaching a tracepoint to sched_switch
|
||||
// and emitting `__u32 value` an a map. See the code template below for more details.
|
||||
relocation_code: &'static str,
|
||||
bpf
|
||||
}
|
||||
|
||||
impl RelocationTest {
|
||||
/// Build a RelocationTestRunner
|
||||
fn build(&self) -> Result<RelocationTestRunner> {
|
||||
Ok(RelocationTestRunner {
|
||||
ebpf: self.build_ebpf()?,
|
||||
btf: self.build_btf()?,
|
||||
})
|
||||
}
|
||||
|
||||
/// - Generate the source eBPF filling a template
|
||||
/// - Compile it with clang
|
||||
fn build_ebpf(&self) -> Result<Vec<u8>> {
|
||||
let local_definition = self.local_definition;
|
||||
let relocation_code = self.relocation_code;
|
||||
let (_tmp_dir, compiled_file) = compile(&format!(
|
||||
r#"
|
||||
#include <linux/bpf.h>
|
||||
|
||||
static long (*bpf_map_update_elem)(void *map, const void *key, const void *value, __u64 flags) = (void *) 2;
|
||||
|
||||
{local_definition}
|
||||
|
||||
struct {{
|
||||
int (*type)[BPF_MAP_TYPE_ARRAY];
|
||||
__u32 *key;
|
||||
__u64 *value;
|
||||
int (*max_entries)[1];
|
||||
}} output_map
|
||||
__attribute__((section(".maps"), used));
|
||||
|
||||
__attribute__((section("tracepoint/bpf_prog"), used))
|
||||
int bpf_prog(void *ctx) {{
|
||||
__u32 key = 0;
|
||||
__u64 value = 0;
|
||||
{relocation_code}
|
||||
bpf_map_update_elem(&output_map, &key, &value, BPF_ANY);
|
||||
return 0;
|
||||
}}
|
||||
|
||||
char _license[] __attribute__((section("license"), used)) = "GPL";
|
||||
"#
|
||||
))
|
||||
.context("Failed to compile eBPF program")?;
|
||||
let bytecode =
|
||||
std::fs::read(compiled_file).context("Error reading compiled eBPF program")?;
|
||||
Ok(bytecode)
|
||||
}
|
||||
|
||||
/// - Generate the target BTF source with a mock main()
|
||||
/// - Compile it with clang
|
||||
/// - Extract the BTF with llvm-objcopy
|
||||
fn build_btf(&self) -> Result<Btf> {
|
||||
let target_btf = self.target_btf;
|
||||
let relocation_code = self.relocation_code;
|
||||
// BTF files can be generated and inspected with these commands:
|
||||
// $ clang -c -g -O2 -target bpf target.c
|
||||
// $ pahole --btf_encode_detached=target.btf -V target.o
|
||||
// $ bpftool btf dump file ./target.btf format c
|
||||
let (tmp_dir, compiled_file) = compile(&format!(
|
||||
r#"
|
||||
#include <linux/bpf.h>
|
||||
|
||||
{target_btf}
|
||||
int main() {{
|
||||
__u64 value = 0;
|
||||
// This is needed to make sure to emit BTF for the defined types,
|
||||
// it could be dead code eliminated if we don't.
|
||||
{relocation_code};
|
||||
return value;
|
||||
}}
|
||||
"#
|
||||
))
|
||||
.context("Failed to compile BTF")?;
|
||||
Command::new("llvm-objcopy")
|
||||
.current_dir(tmp_dir.path())
|
||||
.args(["--dump-section", ".BTF=target.btf"])
|
||||
.arg(compiled_file)
|
||||
.status()
|
||||
.context("Failed to run llvm-objcopy")?
|
||||
.success()
|
||||
.then_some(())
|
||||
.context("Failed to extract BTF")?;
|
||||
let btf = Btf::parse_file(tmp_dir.path().join("target.btf"), Endianness::default())
|
||||
.context("Error parsing generated BTF")?;
|
||||
Ok(btf)
|
||||
}
|
||||
}
|
||||
|
||||
/// Compile an eBPF program and return the path of the compiled object.
|
||||
/// Also returns a TempDir handler, dropping it will clear the created dicretory.
|
||||
fn compile(source_code: &str) -> Result<(TempDir, PathBuf)> {
|
||||
let tmp_dir = tempfile::tempdir().context("Error making temp dir")?;
|
||||
let source = tmp_dir.path().join("source.c");
|
||||
std::fs::write(&source, source_code).context("Writing bpf program failed")?;
|
||||
Command::new("clang")
|
||||
.current_dir(&tmp_dir)
|
||||
.args(["-c", "-g", "-O2", "-target", "bpf"])
|
||||
.arg(&source)
|
||||
.status()
|
||||
.context("Failed to run clang")?
|
||||
.success()
|
||||
.then_some(())
|
||||
.context("Failed to compile eBPF source")?;
|
||||
Ok((tmp_dir, source.with_extension("o")))
|
||||
}
|
||||
|
||||
struct RelocationTestRunner {
|
||||
ebpf: Vec<u8>,
|
||||
btf: Btf,
|
||||
}
|
||||
|
||||
impl RelocationTestRunner {
|
||||
/// Run test and return the output value
|
||||
fn run(&self) -> Result<u64> {
|
||||
self.run_internal(true).context("Error running with BTF")
|
||||
}
|
||||
|
||||
/// Run without loading btf
|
||||
fn run_no_btf(&self) -> Result<u64> {
|
||||
self.run_internal(false)
|
||||
.context("Error running without BTF")
|
||||
}
|
||||
|
||||
fn run_internal(&self, with_relocations: bool) -> Result<u64> {
|
||||
let mut loader = BpfLoader::new();
|
||||
if with_relocations {
|
||||
loader.btf(Some(&self.btf));
|
||||
} else {
|
||||
loader.btf(None);
|
||||
}
|
||||
let mut bpf = loader.load(&self.ebpf).context("Loading eBPF failed")?;
|
||||
let program: &mut TracePoint = bpf
|
||||
.program_mut("bpf_prog")
|
||||
.context("bpf_prog not found")?
|
||||
.try_into()
|
||||
.context("program not a tracepoint")?;
|
||||
program.load().context("Loading tracepoint failed")?;
|
||||
// Attach to sched_switch and wait some time to make sure it executed at least once
|
||||
program
|
||||
.attach("sched", "sched_switch")
|
||||
.context("attach failed")?;
|
||||
sleep(Duration::from_millis(1000));
|
||||
// To inspect the loaded eBPF bytecode, increse the timeout and run:
|
||||
// $ sudo bpftool prog dump xlated name bpf_prog
|
||||
|
||||
let output_map: Array<_, u64> = bpf.take_map("output_map").unwrap().try_into().unwrap();
|
||||
let key = 0;
|
||||
output_map.get(&key, 0).context("Getting key 0 failed")
|
||||
}
|
||||
}
|
||||
#[no_mangle]
|
||||
#[inline(never)]
|
||||
pub extern "C" fn trigger_relocations_program() {}
|
||||
|
||||
Loading…
Reference in New Issue