integration-test: fix BTF relocation test

The struct_flavors test previously expected the same thing with and
without relocations. It now expects different values.

Also rename an enum variant "u64" to "S64". This was a typo. Turns out
that U32 is a type that exists in kernel headers, so all enum values are
suffixed with "_VAL".

Remove stdlib.h and the call to exit(). This alone makes the test fail
with a poisoned relocation. Bringing over the map definition makes the
test work again.

test/integration-test/bpf/reloc.bpf.c

@@ -51,44 +51,48 @@ __attribute__((noinline)) int struct_flavors_global() {
   if (bpf_core_field_exists(s.a)) {
     return set_output(__builtin_preserve_access_index(s.a));
   } else {
-    return set_output(__builtin_preserve_access_index(s.b));
+    return set_output(__builtin_preserve_access_index(s.c));
   }
 }
 
 SEC("uprobe") int struct_flavors(void *ctx) { return struct_flavors_global(); }
 
-enum relocated_enum_unsigned_32 { U32 = 0xAAAAAAAA };
+enum relocated_enum_unsigned_32 { U32_VAL = 0xAAAAAAAA };
 
 __attribute__((noinline)) int enum_unsigned_32_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_32, U32));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_unsigned_32, U32_VAL));
 }
 
 SEC("uprobe") int enum_unsigned_32(void *ctx) {
   return enum_unsigned_32_global();
 }
 
-enum relocated_enum_signed_32 { S32 = -0x7AAAAAAA };
+enum relocated_enum_signed_32 { S32_VAL = -0x7AAAAAAA };
 
 __attribute__((noinline)) int enum_signed_32_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_signed_32, S32));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_signed_32, S32_VAL));
 }
 
 SEC("uprobe") int enum_signed_32(void *ctx) { return enum_signed_32_global(); }
 
-enum relocated_enum_unsigned_64 { U64 = 0xAAAAAAAABBBBBBBB };
+enum relocated_enum_unsigned_64 { U64_VAL = 0xAAAAAAAABBBBBBBB };
 
 __attribute__((noinline)) int enum_unsigned_64_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_64, U64));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_unsigned_64, U64_VAL));
 }
 
 SEC("uprobe") int enum_unsigned_64(void *ctx) {
   return enum_unsigned_64_global();
 }
 
-enum relocated_enum_signed_64 { u64 = -0xAAAAAAABBBBBBBB };
+enum relocated_enum_signed_64 { S64_VAL = -0xAAAAAAABBBBBBBB };
 
 __attribute__((noinline)) int enum_signed_64_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_signed_64, u64));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_signed_64, S64_VAL));
 }
 
 SEC("uprobe") int enum_signed_64(void *ctx) { return enum_signed_64_global(); }

test/integration-test/bpf/reloc.btf.c

@@ -4,9 +4,17 @@
 #include <bpf/bpf_core_read.h>
 // clang-format on
 
-#include <stdlib.h>
-
-long set_output(__u64 value) { exit((int)value); }
+struct {
+  __uint(type, BPF_MAP_TYPE_ARRAY);
+  __type(key, __u32);
+  __type(value, __u64);
+  __uint(max_entries, 1);
+} output_map SEC(".maps");
+
+long set_output(__u64 value) {
+  __u32 key = 0;
+  return bpf_map_update_elem(&output_map, &key, &value, BPF_ANY);
+}
 
 struct relocated_struct_with_scalars {
   __u8 b;
@@ -41,28 +49,32 @@ __attribute__((noinline)) int struct_flavors_global() {
   }
 }
 
-enum relocated_enum_unsigned_32 { U32 = 0xBBBBBBBB };
+enum relocated_enum_unsigned_32 { U32_VAL = 0xBBBBBBBB };
 
 __attribute__((noinline)) int enum_unsigned_32_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_32, U32));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_unsigned_32, U32_VAL));
 }
 
-enum relocated_enum_signed_32 { S32 = -0x7BBBBBBB };
+enum relocated_enum_signed_32 { S32_VAL = -0x7BBBBBBB };
 
 __attribute__((noinline)) int enum_signed_32_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_signed_32, S32));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_signed_32, S32_VAL));
 }
 
-enum relocated_enum_unsigned_64 { U64 = 0xCCCCCCCCDDDDDDDD };
+enum relocated_enum_unsigned_64 { U64_VAL = 0xCCCCCCCCDDDDDDDD };
 
 __attribute__((noinline)) int enum_unsigned_64_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_unsigned_64, U64));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_unsigned_64, U64_VAL));
 }
 
-enum relocated_enum_signed_64 { u64 = -0xCCCCCCCDDDDDDDD };
+enum relocated_enum_signed_64 { S64_VAL = -0xCCCCCCCDDDDDDDD };
 
 __attribute__((noinline)) int enum_signed_64_global() {
-  return set_output(bpf_core_enum_value(enum relocated_enum_signed_64, u64));
+  return set_output(
+      bpf_core_enum_value(enum relocated_enum_signed_64, S64_VAL));
 }
 
 // Avoids dead code elimination by the compiler.

test/integration-test/src/tests/btf_relocations.rs

@@ -2,20 +2,20 @@ use test_case::test_case;
 
 use aya::{maps::Array, programs::UProbe, util::KernelVersion, BpfLoader, Btf, Endianness};
 
-#[test_case("field", false, None, 2)]
-#[test_case("field", true, None, 1)]
+#[test_case("enum_signed_32", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0x7AAAAAAAi32 as u64)]
+#[test_case("enum_signed_32", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0x7BBBBBBBi32 as u64)]
+#[test_case("enum_signed_64", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0xAAAAAAABBBBBBBBi64 as u64)]
+#[test_case("enum_signed_64", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0xCCCCCCCDDDDDDDDi64 as u64)]
 #[test_case("enum_unsigned_32", false, None, 0xAAAAAAAA)]
 #[test_case("enum_unsigned_32", true, None, 0xBBBBBBBB)]
+#[test_case("enum_unsigned_64", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), 0xAAAAAAAABBBBBBBB)]
+#[test_case("enum_unsigned_64", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), 0xCCCCCCCCDDDDDDDD)]
+#[test_case("field", false, None, 2)]
+#[test_case("field", true, None, 1)]
 #[test_case("pointer", false, None, 42)]
 #[test_case("pointer", true, None, 21)]
 #[test_case("struct_flavors", false, None, 1)]
-#[test_case("struct_flavors", true, None, 1)]
-#[test_case("enum_signed_32", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0x7AAAAAAAi32 as u64)]
-#[test_case("enum_signed_32", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0x7BBBBBBBi32 as u64)]
-#[test_case("enum_unsigned_64", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), 0xAAAAAAAABBBBBBBB)]
-#[test_case("enum_unsigned_64", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), 0xCCCCCCCCDDDDDDDD)]
-#[test_case("enum_signed_64", false, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0xAAAAAAABBBBBBBBi64 as u64)]
-#[test_case("enum_signed_64", true, Some((KernelVersion::new(6, 0, 0), "https://github.com/torvalds/linux/commit/6089fb3")), -0xCCCCCCCDDDDDDDDi64 as u64)]
+#[test_case("struct_flavors", true, None, 2)]
 fn relocation_tests(
     program: &str,
     with_relocations: bool,