selftests/bpf: add CO-RE relocs nesting tests

Add a bunch of test validating correct handling of nested
structs/unions.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 293 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index 33b0c6a61912..340ee2bcd463 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -13,3 +13,296 @@ struct core_reloc_flavors__err_wrong_name {
 	int b;
 	int c;
 };
+
+/*
+ * NESTING
+ */
+/* original set up, used to record relocations in BPF program */
+struct core_reloc_nesting_substruct {
+	int a;
+};
+
+union core_reloc_nesting_subunion {
+	int b;
+};
+
+struct core_reloc_nesting {
+	union {
+		struct core_reloc_nesting_substruct a;
+	} a;
+	struct {
+		union core_reloc_nesting_subunion b;
+	} b;
+};
+
+/* inlined anonymous struct/union instead of named structs in original */
+struct core_reloc_nesting___anon_embed {
+	int __just_for_padding;
+	union {
+		struct {
+			int a;
+		} a;
+	} a;
+	struct {
+		union {
+			int b;
+		} b;
+	} b;
+};
+
+/* different mix of nested structs/unions than in original */
+struct core_reloc_nesting___struct_union_mixup {
+	int __a;
+	struct {
+		int __a;
+		union {
+			char __a;
+			int a;
+		} a;
+	} a;
+	int __b;
+	union {
+		int __b;
+		union {
+			char __b;
+			int b;
+		} b;
+	} b;
+};
+
+/* extra anon structs/unions, but still valid a.a.a and b.b.b accessors */
+struct core_reloc_nesting___extra_nesting {
+	int __padding;
+	struct {
+		struct {
+			struct {
+				struct {
+					union {
+						int a;
+					} a;
+				};
+			};
+		} a;
+		int __some_more;
+		struct {
+			union {
+				union {
+					union {
+						struct {
+							int b;
+						};
+					} b;
+				};
+			} b;
+		};
+	};
+};
+
+/* three flavors of same struct with different structure but same layout for
+ * a.a.a and b.b.b, thus successfully resolved and relocatable */
+struct core_reloc_nesting___dup_compat_types {
+	char __just_for_padding;
+	/* 3 more bytes of padding */
+	struct {
+		struct {
+			int a; /* offset 4 */
+		} a;
+	} a;
+	long long __more_padding;
+	struct {
+		struct {
+			int b; /* offset 16 */
+		} b;
+	} b;
+};
+
+struct core_reloc_nesting___dup_compat_types__2 {
+	int __aligned_padding;
+	struct {
+		int __trickier_noop[0];
+		struct {
+			char __some_more_noops[0];
+			int a; /* offset 4 */
+		} a;
+	} a;
+	int __more_padding;
+	struct {
+		struct {
+			struct {
+				int __critical_padding;
+				int b; /* offset 16 */
+			} b;
+			int __does_not_matter;
+		};
+	} b;
+	int __more_irrelevant_stuff;
+};
+
+struct core_reloc_nesting___dup_compat_types__3 {
+	char __correct_padding[4];
+	struct {
+		struct {
+			int a; /* offset 4 */
+		} a;
+	} a;
+	/* 8 byte padding due to next struct's alignment */
+	struct {
+		struct {
+			int b;
+		} b;
+	} b __attribute__((aligned(16)));
+};
+
+/* b.b.b field is missing */
+struct core_reloc_nesting___err_missing_field {
+	struct {
+		struct {
+			int a;
+		} a;
+	} a;
+	struct {
+		struct {
+			int x;
+		} b;
+	} b;
+};
+
+/* b.b.b field is an array of integers instead of plain int */
+struct core_reloc_nesting___err_array_field {
+	struct {
+		struct {
+			int a;
+		} a;
+	} a;
+	struct {
+		struct {
+			int b[1];
+		} b;
+	} b;
+};
+
+/* middle b container is missing */
+struct core_reloc_nesting___err_missing_container {
+	struct {
+		struct {
+			int a;
+		} a;
+	} a;
+	struct {
+		int x;
+	} b;
+};
+
+/* middle b container is referenced through pointer instead of being embedded */
+struct core_reloc_nesting___err_nonstruct_container {
+	struct {
+		struct {
+			int a;
+		} a;
+	} a;
+	struct {
+		struct {
+			int b;
+		} *b;
+	} b;
+};
+
+/* middle b container is an array of structs instead of plain struct */
+struct core_reloc_nesting___err_array_container {
+	struct {
+		struct {
+			int a;
+		} a;
+	} a;
+	struct {
+		struct {
+			int b;
+		} b[1];
+	} b;
+};
+
+/* two flavors of same struct with incompatible layout for b.b.b */
+struct core_reloc_nesting___err_dup_incompat_types__1 {
+	struct {
+		struct {
+			int a; /* offset 0 */
+		} a;
+	} a;
+	struct {
+		struct {
+			int b; /* offset 4 */
+		} b;
+	} b;
+};
+
+struct core_reloc_nesting___err_dup_incompat_types__2 {
+	struct {
+		struct {
+			int a; /* offset 0 */
+		} a;
+	} a;
+	int __extra_padding;
+	struct {
+		struct {
+			int b; /* offset 8 (!) */
+		} b;
+	} b;
+};
+
+/* two flavors of same struct having one of a.a.a and b.b.b, but not both */
+struct core_reloc_nesting___err_partial_match_dups__a {
+	struct {
+		struct {
+			int a;
+		} a;
+	} a;
+};
+
+struct core_reloc_nesting___err_partial_match_dups__b {
+	struct {
+		struct {
+			int b;
+		} b;
+	} b;
+};
+
+struct core_reloc_nesting___err_too_deep {
+	struct {
+		struct {
+			int a;
+		} a;
+	} a;
+	/* 65 levels of nestedness for b.b.b */
+	struct {
+		struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+			struct { struct { struct { struct { struct {
+				/* this one is one too much */
+				struct {
+					int b;
+				};
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+			}; }; }; }; };
+		} b;
+	} b;
+};