mirror of https://github.com/aya-rs/aya
Merge pull request #706 from aya-rs/reloc-tests
integration-test: Remove runtime toolchain depsreviewable/pr638/r6
Tamir Duberstein
1 year ago
committed by
GitHub
commit
3692e53ff0
@ -0,0 +1,106 @@
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// clang-format off
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_core_read.h>
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// clang-format on
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char _license[] __attribute__((section("license"), used)) = "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, 1);
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} output_map SEC(".maps");
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long set_output(__u64 value) {
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__u32 key = 0;
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return bpf_map_update_elem(&output_map, &key, &value, BPF_ANY);
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}
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struct relocated_struct_with_scalars {
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__u8 a;
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__u8 b;
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__u8 c;
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};
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__attribute__((noinline)) int field_global() {
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struct relocated_struct_with_scalars s = {1, 2, 3};
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return set_output(__builtin_preserve_access_index(s.b));
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}
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SEC("uprobe/field") int field(void *ctx) {
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return field_global();
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}
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struct relocated_struct_with_pointer {
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struct relocated_struct_with_pointer *first;
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struct relocated_struct_with_pointer *second;
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};
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__attribute__((noinline)) int pointer_global() {
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struct relocated_struct_with_pointer s = {
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(struct relocated_struct_with_pointer *)42,
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(struct relocated_struct_with_pointer *)21,
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};
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return set_output((__u64)__builtin_preserve_access_index(s.first));
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}
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SEC("uprobe/pointer") int pointer(void *ctx) {
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return pointer_global();
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}
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__attribute__((noinline)) int struct_flavors_global() {
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struct relocated_struct_with_scalars s = {1, 2, 3};
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if (bpf_core_field_exists(s.a)) {
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return set_output(__builtin_preserve_access_index(s.a));
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} else {
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return set_output(__builtin_preserve_access_index(s.b));
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}
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}
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SEC("uprobe/struct_flavors") int struct_flavors(void *ctx) {
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return struct_flavors_global();
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}
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enum relocated_enum_unsigned_32 { U32 = 0xAAAAAAAA };
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__attribute__((noinline)) int enum_unsigned_32_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_32, U32));
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}
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SEC("uprobe/enum_unsigned_32")
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int enum_unsigned_32(void *ctx) {
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return enum_unsigned_32_global();
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}
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enum relocated_enum_signed_32 { S32 = -0x7AAAAAAA };
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__attribute__((noinline)) int enum_signed_32_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_signed_32, S32));
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}
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SEC("uprobe/enum_signed_32") int enum_signed_32(void *ctx) {
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return enum_signed_32_global();
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}
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enum relocated_enum_unsigned_64 { U64 = 0xAAAAAAAABBBBBBBB };
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__attribute__((noinline)) int enum_unsigned_64_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_64, U64));
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}
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SEC("uprobe/enum_unsigned_64")
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int enum_unsigned_64(void *ctx) {
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return enum_unsigned_64_global();
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}
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enum relocated_enum_signed_64 { u64 = -0xAAAAAAABBBBBBBB };
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__attribute__((noinline)) int enum_signed_64_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_signed_64, u64));
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}
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SEC("uprobe/enum_signed_64") int enum_signed_64(void *ctx) {
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return enum_signed_64_global();
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}
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@ -0,0 +1,77 @@
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// clang-format off
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_core_read.h>
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// clang-format on
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#include <stdlib.h>
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long set_output(__u64 value) { exit((int)value); }
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struct relocated_struct_with_scalars {
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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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__attribute__((noinline)) int field_global() {
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struct relocated_struct_with_scalars s = {1, 2, 3};
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return set_output(__builtin_preserve_access_index(s.b));
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}
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struct relocated_struct_with_pointer {
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struct relocated_struct_with_pointer *second;
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struct relocated_struct_with_pointer *first;
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};
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__attribute__((noinline)) int pointer_global() {
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struct relocated_struct_with_pointer s = {
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(struct relocated_struct_with_pointer *)42,
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(struct relocated_struct_with_pointer *)21,
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};
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return set_output((__u64)__builtin_preserve_access_index(s.first));
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}
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__attribute__((noinline)) int struct_flavors_global() {
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struct relocated_struct_with_scalars s = {1, 2, 3};
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if (bpf_core_field_exists(s.b)) {
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return set_output(__builtin_preserve_access_index(s.b));
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} else {
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return set_output(__builtin_preserve_access_index(s.c));
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}
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}
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enum relocated_enum_unsigned_32 { U32 = 0xBBBBBBBB };
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__attribute__((noinline)) int enum_unsigned_32_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_32, U32));
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}
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enum relocated_enum_signed_32 { S32 = -0x7BBBBBBB };
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__attribute__((noinline)) int enum_signed_32_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_signed_32, S32));
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}
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enum relocated_enum_unsigned_64 { U64 = 0xCCCCCCCCDDDDDDDD };
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__attribute__((noinline)) int enum_unsigned_64_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_64, U64));
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}
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enum relocated_enum_signed_64 { u64 = -0xCCCCCCCDDDDDDDD };
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__attribute__((noinline)) int enum_signed_64_global() {
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return set_output(bpf_core_enum_value(enum relocated_enum_signed_64, u64));
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}
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// Avoids dead code elimination by the compiler.
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int main() {
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field_global();
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pointer_global();
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struct_flavors_global();
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enum_unsigned_32_global();
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enum_signed_32_global();
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enum_unsigned_64_global();
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enum_signed_64_global();
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}
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@ -1,405 +1,62 @@
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use anyhow::{anyhow, bail, Context as _, Result};
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use std::{
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process::{Child, ChildStdout, Command, Stdio},
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thread::sleep,
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time::Duration,
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};
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use aya::{maps::Array, programs::TracePoint, util::KernelVersion, BpfLoader, Btf, Endianness};
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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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#[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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#[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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#[test]
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fn relocate_enum_signed() {
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let kernel_version = KernelVersion::current().unwrap();
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if kernel_version < KernelVersion::new(6, 0, 0) {
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eprintln!("skipping test on kernel {kernel_version:?}, support for signed enum was added in 6.0.0; see https://github.com/torvalds/linux/commit/6089fb3");
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use test_case::test_case;
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use aya::{maps::Array, programs::UProbe, util::KernelVersion, BpfLoader, Btf, Endianness};
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#[test_case("field", false, None, 2)]
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#[test_case("field", true, None, 1)]
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#[test_case("enum_unsigned_32", false, None, 0xAAAAAAAA)]
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#[test_case("enum_unsigned_32", true, None, 0xBBBBBBBB)]
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#[test_case("pointer", false, None, 42)]
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#[test_case("pointer", true, None, 21)]
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#[test_case("struct_flavors", false, None, 1)]
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#[test_case("struct_flavors", true, None, 1)]
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#[test_case("enum_signed_32", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0x7AAAAAAAi32 as u64)]
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#[test_case("enum_signed_32", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0x7BBBBBBBi32 as u64)]
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#[test_case("enum_unsigned_64", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), 0xAAAAAAAABBBBBBBB)]
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#[test_case("enum_unsigned_64", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), 0xCCCCCCCCDDDDDDDD)]
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#[test_case("enum_signed_64", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0xAAAAAAABBBBBBBBi64 as u64)]
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#[test_case("enum_signed_64", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0xCCCCCCCDDDDDDDDi64 as u64)]
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fn relocation_tests(
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program: &str,
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with_relocations: bool,
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required_kernel_version: Option<(KernelVersion, &str)>,
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expected: u64,
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) {
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if let Some((required_kernel_version, commit)) = required_kernel_version {
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let current_kernel_version = KernelVersion::current().unwrap();
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if current_kernel_version < required_kernel_version {
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eprintln!("skipping test on kernel {current_kernel_version:?}, support for {program} was added in {required_kernel_version:?}; see {commit}");
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return;
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}
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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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let mut bpf = BpfLoader::new()
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.btf(
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with_relocations
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.then(|| Btf::parse(crate::RELOC_BTF, Endianness::default()).unwrap())
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.as_ref(),
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)
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.load(crate::RELOC_BPF)
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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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#[test]
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fn relocate_enum64() {
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let kernel_version = KernelVersion::current().unwrap();
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if kernel_version < KernelVersion::new(6, 0, 0) {
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eprintln!("skipping test on kernel {kernel_version:?}, support for enum64 was added in 6.0.0; see https://github.com/torvalds/linux/commit/6089fb3");
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return;
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}
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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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#[test]
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fn relocate_enum64_signed() {
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let kernel_version = KernelVersion::current().unwrap();
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if kernel_version < KernelVersion::new(6, 0, 0) {
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eprintln!("skipping test on kernel {kernel_version:?}, support for enum64 was added in 6.0.0; see https://github.com/torvalds/linux/commit/6089fb3");
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return;
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}
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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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|
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#[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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|
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#[test]
|
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fn relocate_struct_flavors() {
|
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let definition = r#"
|
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struct foo {};
|
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struct bar { struct foo *f; };
|
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struct bar___cafe { struct foo *e; struct foo *f; };
|
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"#;
|
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|
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let relocation_code = r#"
|
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__u8 memory[] = {42, 0, 0, 0, 0, 0, 0, 0, 21, 0, 0, 0, 0, 0, 0, 0};
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struct bar* ptr = (struct bar *) &memory;
|
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|
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if (__builtin_preserve_field_info((((typeof(struct bar___cafe) *)0)->e), 2)) {
|
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value = (__u64) __builtin_preserve_access_index(((struct bar___cafe *)ptr)->e);
|
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} else {
|
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value = (__u64) __builtin_preserve_access_index(ptr->f);
|
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}
|
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"#;
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|
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let test_no_flavor = RelocationTest {
|
||||
local_definition: definition,
|
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target_btf: definition,
|
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relocation_code,
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}
|
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.build()
|
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let program: &mut UProbe = bpf.program_mut(program).unwrap().try_into().unwrap();
|
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program.load().unwrap();
|
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program
|
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.attach(
|
||||
Some("trigger_btf_relocations_program"),
|
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0,
|
||||
"/proc/self/exe",
|
||||
None,
|
||||
)
|
||||
.unwrap();
|
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assert_eq!(test_no_flavor.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,
|
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/// Target data structure definition. What the vmlinux would actually contain.
|
||||
target_btf: &'static str,
|
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/// Code executed by the eBPF program to test the relocation.
|
||||
/// The format should be:
|
||||
// __u8 memory[] = { ... };
|
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// __u32 value = BPF_CORE_READ((struct foo *)&memory, ...);
|
||||
//
|
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// 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,
|
||||
}
|
||||
|
||||
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>> {
|
||||
use std::io::Read as _;
|
||||
|
||||
let Self {
|
||||
local_definition,
|
||||
relocation_code,
|
||||
..
|
||||
} = self;
|
||||
|
||||
let mut stdout = 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__ ((noinline)) int bpf_func() {{
|
||||
__u32 key = 0;
|
||||
__u64 value = 0;
|
||||
{relocation_code}
|
||||
bpf_map_update_elem(&output_map, &key, &value, BPF_ANY);
|
||||
return 0;
|
||||
}}
|
||||
|
||||
__attribute__((section("tracepoint/bpf_prog"), used))
|
||||
int bpf_prog(void *ctx) {{
|
||||
bpf_func();
|
||||
return 0;
|
||||
}}
|
||||
|
||||
char _license[] __attribute__((section("license"), used)) = "GPL";
|
||||
"#
|
||||
))
|
||||
.context("failed to compile eBPF program")?;
|
||||
let mut output = Vec::new();
|
||||
stdout.read_to_end(&mut output)?;
|
||||
Ok(output)
|
||||
}
|
||||
|
||||
/// - 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> {
|
||||
use std::io::Read as _;
|
||||
|
||||
let Self {
|
||||
target_btf,
|
||||
relocation_code,
|
||||
..
|
||||
} = self;
|
||||
|
||||
// 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 stdout = 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")?;
|
||||
|
||||
let mut cmd = Command::new("llvm-objcopy");
|
||||
cmd.args(["--dump-section", ".BTF=-", "-"])
|
||||
.stdin(stdout)
|
||||
.stdout(Stdio::piped());
|
||||
let mut child = cmd
|
||||
.spawn()
|
||||
.with_context(|| format!("failed to spawn {cmd:?}"))?;
|
||||
let Child { stdout, .. } = &mut child;
|
||||
let mut stdout = stdout.take().ok_or(anyhow!("failed to open stdout"))?;
|
||||
let status = child
|
||||
.wait()
|
||||
.with_context(|| format!("failed to wait for {cmd:?}"))?;
|
||||
match status.code() {
|
||||
Some(code) => match code {
|
||||
0 => {}
|
||||
code => bail!("{cmd:?} exited with code {code}"),
|
||||
},
|
||||
None => bail!("{cmd:?} terminated by signal"),
|
||||
}
|
||||
|
||||
let mut output = Vec::new();
|
||||
stdout.read_to_end(&mut output)?;
|
||||
|
||||
Btf::parse(output.as_slice(), Endianness::default())
|
||||
.context("failed to parse generated BTF")
|
||||
}
|
||||
}
|
||||
|
||||
/// Compile an eBPF program and return its bytes.
|
||||
fn compile(source_code: &str) -> Result<ChildStdout> {
|
||||
use std::io::Write as _;
|
||||
|
||||
let mut cmd = Command::new("clang");
|
||||
cmd.args([
|
||||
"-c", "-g", "-O2", "-target", "bpf", "-x", "c", "-", "-o", "-",
|
||||
])
|
||||
.stdin(Stdio::piped())
|
||||
.stdout(Stdio::piped());
|
||||
let mut child = cmd
|
||||
.spawn()
|
||||
.with_context(|| format!("failed to spawn {cmd:?}"))?;
|
||||
let Child { stdin, stdout, .. } = &mut child;
|
||||
{
|
||||
let mut stdin = stdin.take().ok_or(anyhow!("failed to open stdin"))?;
|
||||
stdin
|
||||
.write_all(source_code.as_bytes())
|
||||
.context("failed to write to stdin")?;
|
||||
}
|
||||
let stdout = stdout.take().ok_or(anyhow!("failed to open stdout"))?;
|
||||
let status = child
|
||||
.wait()
|
||||
.with_context(|| format!("failed to wait for {cmd:?}"))?;
|
||||
match status.code() {
|
||||
Some(code) => match code {
|
||||
0 => {}
|
||||
code => bail!("{cmd:?} exited with code {code}"),
|
||||
},
|
||||
None => bail!("{cmd:?} terminated by signal"),
|
||||
}
|
||||
Ok(stdout)
|
||||
}
|
||||
|
||||
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
|
||||
trigger_btf_relocations_program();
|
||||
|
||||
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")
|
||||
assert_eq!(output_map.get(&key, 0).unwrap(), expected)
|
||||
}
|
||||
|
||||
#[no_mangle]
|
||||
#[inline(never)]
|
||||
pub extern "C" fn trigger_btf_relocations_program() {
|
||||
core::hint::black_box(trigger_btf_relocations_program);
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue