selftests/bpf: Add field size relocation tests

Add test verifying correctness and logic of field size relocation support in
libbpf.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191101222810.1246166-6-andriin@fb.com

diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index 340aa12..00f1f32 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -174,15 +174,11 @@
        .fails = true,                                                  \
 }
 
-#define EXISTENCE_DATA(struct_name) STRUCT_TO_CHAR_PTR(struct_name) {  \
-       .a = 42,                                                        \
-}
-
 #define EXISTENCE_CASE_COMMON(name)                                    \
        .case_name = #name,                                             \
        .bpf_obj_file = "test_core_reloc_existence.o",                  \
        .btf_src_file = "btf__core_reloc_" #name ".o",                  \
-       .relaxed_core_relocs = true                                     \
+       .relaxed_core_relocs = true
 
 #define EXISTENCE_ERR_CASE(name) {                                     \
        EXISTENCE_CASE_COMMON(name),                                    \
@@ -225,6 +221,35 @@
        .fails = true,                                                  \
 }
 
+#define SIZE_CASE_COMMON(name)                                         \
+       .case_name = #name,                                             \
+       .bpf_obj_file = "test_core_reloc_size.o",                       \
+       .btf_src_file = "btf__core_reloc_" #name ".o",                  \
+       .relaxed_core_relocs = true
+
+#define SIZE_OUTPUT_DATA(type)                                         \
+       STRUCT_TO_CHAR_PTR(core_reloc_size_output) {                    \
+               .int_sz = sizeof(((type *)0)->int_field),               \
+               .struct_sz = sizeof(((type *)0)->struct_field),         \
+               .union_sz = sizeof(((type *)0)->union_field),           \
+               .arr_sz = sizeof(((type *)0)->arr_field),               \
+               .arr_elem_sz = sizeof(((type *)0)->arr_field[0]),       \
+               .ptr_sz = sizeof(((type *)0)->ptr_field),               \
+               .enum_sz = sizeof(((type *)0)->enum_field),     \
+       }
+
+#define SIZE_CASE(name) {                                              \
+       SIZE_CASE_COMMON(name),                                         \
+       .input_len = 0,                                                 \
+       .output = SIZE_OUTPUT_DATA(struct core_reloc_##name),           \
+       .output_len = sizeof(struct core_reloc_size_output),            \
+}
+
+#define SIZE_ERR_CASE(name) {                                          \
+       SIZE_CASE_COMMON(name),                                         \
+       .fails = true,                                                  \
+}
+
 struct core_reloc_test_case {
        const char *case_name;
        const char *bpf_obj_file;
@@ -423,6 +448,10 @@ static struct core_reloc_test_case test_cases[] = {
                .ub2 = 0x0812345678FEDCBA,
        }),
        BITFIELDS_ERR_CASE(bitfields___err_too_big_bitfield),
+
+       /* size relocation checks */
+       SIZE_CASE(size),
+       SIZE_CASE(size___diff_sz),
 };
 
 struct data {

diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_size.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_size.c
new file mode 100644 (file)
index 0000000..3c80903
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_size.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_size x) {}

diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_size___diff_sz.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_size___diff_sz.c
new file mode 100644 (file)
index 0000000..6dbd144
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_size___diff_sz.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_size___diff_sz x) {}

diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index 7eb08d9..9311489 100644 (file)
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -734,3 +734,34 @@ struct core_reloc_bitfields___err_too_big_bitfield {
        uint32_t        u32;
        uint32_t        s32;
 } __attribute__((packed)) ;
+
+/*
+ * SIZE
+ */
+struct core_reloc_size_output {
+       int int_sz;
+       int struct_sz;
+       int union_sz;
+       int arr_sz;
+       int arr_elem_sz;
+       int ptr_sz;
+       int enum_sz;
+};
+
+struct core_reloc_size {
+       int int_field;
+       struct { int x; } struct_field;
+       union { int x; } union_field;
+       int arr_field[4];
+       void *ptr_field;
+       enum { VALUE = 123 } enum_field;
+};
+
+struct core_reloc_size___diff_sz {
+       uint64_t int_field;
+       struct { int x; int y; int z; } struct_field;
+       union { int x; char bla[123]; } union_field;
+       char arr_field[10];
+       void *ptr_field;
+       enum { OTHER_VALUE = 0xFFFFFFFFFFFFFFFF } enum_field;
+};

diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_size.c b/tools/testing/selftests/bpf/progs/test_core_reloc_size.c
new file mode 100644 (file)
index 0000000..9a92998
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_size.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include "bpf_helpers.h"
+#include "bpf_core_read.h"
+
+char _license[] SEC("license") = "GPL";
+
+static volatile struct data {
+       char in[256];
+       char out[256];
+} data;
+
+struct core_reloc_size_output {
+       int int_sz;
+       int struct_sz;
+       int union_sz;
+       int arr_sz;
+       int arr_elem_sz;
+       int ptr_sz;
+       int enum_sz;
+};
+
+struct core_reloc_size {
+       int int_field;
+       struct { int x; } struct_field;
+       union { int x; } union_field;
+       int arr_field[4];
+       void *ptr_field;
+       enum { VALUE = 123 } enum_field;
+};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_size(void *ctx)
+{
+       struct core_reloc_size *in = (void *)&data.in;
+       struct core_reloc_size_output *out = (void *)&data.out;
+
+       out->int_sz = bpf_core_field_size(in->int_field);
+       out->struct_sz = bpf_core_field_size(in->struct_field);
+       out->union_sz = bpf_core_field_size(in->union_field);
+       out->arr_sz = bpf_core_field_size(in->arr_field);
+       out->arr_elem_sz = bpf_core_field_size(in->arr_field[0]);
+       out->ptr_sz = bpf_core_field_size(in->ptr_field);
+       out->enum_sz = bpf_core_field_size(in->enum_field);
+
+       return 0;
+}
+