[PATCH v2 bpf-next 12/12] selftests/bpf: add CO-RE relocs misc tests

Andrii Nakryiko
2019-07-30T19:54:46Z

Add tests validating few edge-cases of capturing offset relocations.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
.../selftests/bpf/prog_tests/core_reloc.c | 19 ++++++
.../bpf/progs/btf__core_reloc_misc.c | 4 ++
.../selftests/bpf/progs/core_reloc_types.h | 25 ++++++++
.../bpf/progs/test_core_reloc_misc.c | 58 +++++++++++++++++++
4 files changed, 106 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_misc.c
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_misc.c

diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index 46abb4df5b1c..a50ad439ea90 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -260,6 +260,25 @@ static struct core_reloc_test_case test_cases[] = {
INTS_ERR_CASE(ints___err_wrong_sz_16),
INTS_ERR_CASE(ints___err_wrong_sz_32),
INTS_ERR_CASE(ints___err_wrong_sz_64),
+
+ /* validate edge cases of capturing relocations */
+ {
+ .case_name = "misc",
+ .bpf_obj_file = "test_core_reloc_misc.o",
+ .btf_src_file = "btf__core_reloc_misc.o",
+ .input = (const char *)&(struct core_reloc_misc_extensible[]){
+ { .a = 1 },
+ { .a = 2 }, /* not read */
+ { .a = 3 },
+ },
+ .input_len = 4 * sizeof(int),
+ .output = STRUCT_TO_CHAR_PTR(core_reloc_misc_output) {
+ .a = 1,
+ .b = 1,
+ .c = 0, /* BUG in clang, should be 3 */
+ },
+ .output_len = sizeof(struct core_reloc_misc_output),
+ },
};

struct data {
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_misc.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_misc.c
new file mode 100644
index 000000000000..e379831d31a8
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_misc.c
@@ -0,0 +1,4 @@
+#include "core_reloc_types.h"
+
+void f1(struct core_reloc_misc___a x) {}
+void f2(struct core_reloc_misc___b x) {}
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index 5f3ebd4f6dc3..10a252b6da55 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -640,3 +640,28 @@ struct core_reloc_ints___err_wrong_sz_64 {
uint32_t u64_field; /* not 64-bit anymore */
int32_t s64_field; /* not 64-bit anymore */
};
+
+/*
+ * MISC
+ */
+struct core_reloc_misc_output {
+ int a, b, c;
+};
+
+struct core_reloc_misc___a {
+ int a1;
+ int a2;
+};
+
+struct core_reloc_misc___b {
+ int b1;
+ int b2;
+};
+
+/* this one extends core_reloc_misc_extensible struct from BPF prog */
+struct core_reloc_misc_extensible {
+ int a;
+ int b;
+ int c;
+ int d;
+};
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_misc.c b/tools/testing/selftests/bpf/progs/test_core_reloc_misc.c
new file mode 100644
index 000000000000..bfd295f23d5f
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_misc.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include "bpf_helpers.h"
+
+char _license[] SEC("license") = "GPL";
+
+static volatile struct data {
+ char in[256];
+ char out[256];
+} data;
+
+struct core_reloc_misc_output {
+ int a, b, c;
+};
+
+struct core_reloc_misc___a {
+ int a1;
+ int a2;
+};
+
+struct core_reloc_misc___b {
+ int b1;
+ int b2;
+};
+
+/* fixed two first members, can be extended with new fields */
+struct core_reloc_misc_extensible {
+ int a;
+ int b;
+};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_misc(void *ctx)
+{
+ struct core_reloc_misc___a *in_a = (void *)&data.in;
+ struct core_reloc_misc___b *in_b = (void *)&data.in;
+ struct core_reloc_misc_extensible *in_ext = (void *)&data.in;
+ struct core_reloc_misc_output *out = (void *)&data.out;
+
+ /* record two different relocations with the same accessor string */
+ if (BPF_CORE_READ(&out->a, &in_a->a1) || /* accessor: 0:0 */
+ BPF_CORE_READ(&out->b, &in_b->b1)) /* accessor: 0:0 */
+ return 1;
+
+ /* Validate relocations capture array-only accesses for structs with
+ * fixed header, but with potentially extendable tail. This will read
+ * first 4 bytes of 2nd element of in_ext array of potentially
+ * variably sized struct core_reloc_misc_extensible. */
+ /* BUG in Clang, isn't captured right now */
+ if (BPF_CORE_READ(&out->c, &in_ext[2])) /* accessor: 2 */
+ return 1;
+
+ return 0;
+}
+
--
2.17.1