Add a self-tests validating libbpf is able to perform CO-RE relocations
against the type defined in kernel module BTF. if bpf_testmod.o is not
supported by the kernel (e.g., due to version mismatch), skip tests, instead
of failing.
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
---
.../selftests/bpf/prog_tests/core_reloc.c | 79 ++++++++++++++++---
.../selftests/bpf/progs/core_reloc_types.h | 17 ++++
.../bpf/progs/test_core_reloc_module.c | 66 ++++++++++++++++
3 files changed, 151 insertions(+), 11 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_module.c
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index 30e40ff4b0d8..bb980848cd77 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include "progs/core_reloc_types.h"
+#include "bpf_testmod/bpf_testmod.h"
#include <sys/mman.h>
#include <sys/syscall.h>
#include <bpf/btf.h>
@@ -9,6 +10,30 @@ static int duration = 0;
#define STRUCT_TO_CHAR_PTR(struct_name) (const char *)&(struct struct_name)
+#define MODULES_CASE(name, sec_name, tp_name) { \
+ .case_name = name, \
+ .bpf_obj_file = "test_core_reloc_module.o", \
+ .btf_src_file = NULL, /* find in kernel module BTFs */ \
+ .input = "", \
+ .input_len = 0, \
+ .output = STRUCT_TO_CHAR_PTR(core_reloc_module_output) { \
+ .read_ctx_sz = sizeof(struct bpf_testmod_test_read_ctx),\
+ .read_ctx_exists = true, \
+ .buf_exists = true, \
+ .len_exists = true, \
+ .off_exists = true, \
+ .len = 123, \
+ .off = 0, \
+ .comm = "test_progs", \
+ .comm_len = sizeof("test_progs"), \
+ }, \
+ .output_len = sizeof(struct core_reloc_module_output), \
+ .prog_sec_name = sec_name, \
+ .raw_tp_name = tp_name, \
+ .trigger = trigger_module_test_read, \
+ .needs_testmod = true, \
+}
+
#define FLAVORS_DATA(struct_name) STRUCT_TO_CHAR_PTR(struct_name) { \
.a = 42, \
.b = 0xc001, \
@@ -211,7 +236,7 @@ static int duration = 0;
.output = STRUCT_TO_CHAR_PTR(core_reloc_bitfields_output) \
__VA_ARGS__, \
.output_len = sizeof(struct core_reloc_bitfields_output), \
- .direct_raw_tp = true, \
+ .prog_sec_name = "tp_btf/sys_enter", \
}
@@ -222,7 +247,7 @@ static int duration = 0;
}, { \
BITFIELDS_CASE_COMMON("test_core_reloc_bitfields_direct.o", \
"direct:", name), \
- .direct_raw_tp = true, \
+ .prog_sec_name = "tp_btf/sys_enter", \
.fails = true, \
}
@@ -309,6 +334,7 @@ static int duration = 0;
struct core_reloc_test_case;
typedef int (*setup_test_fn)(struct core_reloc_test_case *test);
+typedef int (*trigger_test_fn)(const struct core_reloc_test_case *test);
struct core_reloc_test_case {
const char *case_name;
@@ -319,9 +345,12 @@ struct core_reloc_test_case {
const char *output;
int output_len;
bool fails;
+ bool needs_testmod;
bool relaxed_core_relocs;
- bool direct_raw_tp;
+ const char *prog_sec_name;
+ const char *raw_tp_name;
setup_test_fn setup;
+ trigger_test_fn trigger;
};
static int find_btf_type(const struct btf *btf, const char *name, __u32 kind)
@@ -451,6 +480,23 @@ static int setup_type_id_case_failure(struct core_reloc_test_case *test)
return 0;
}
+static int trigger_module_test_read(const struct core_reloc_test_case *test)
+{
+ struct core_reloc_module_output *exp = (void *)test->output;
+ int fd, err;
+
+ fd = open("/sys/kernel/bpf_testmod", O_RDONLY);
+ err = -errno;
+ if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
+ return err;
+
+ read(fd, NULL, exp->len); /* request expected number of bytes */
+ close(fd);
+
+ return 0;
+}
+
+
static struct core_reloc_test_case test_cases[] = {
/* validate we can find kernel image and use its BTF for relocs */
{
@@ -467,6 +513,9 @@ static struct core_reloc_test_case test_cases[] = {
.output_len = sizeof(struct core_reloc_kernel_output),
},
+ /* validate we can find kernel module BTF types for relocs/attach */
+ MODULES_CASE("module", "raw_tp/bpf_testmod_test_read", "bpf_testmod_test_read"),
+
/* validate BPF program can use multiple flavors to match against
* single target BTF type
*/
@@ -779,6 +828,11 @@ void test_core_reloc(void)
if (!test__start_subtest(test_case->case_name))
continue;
+ if (test_case->needs_testmod && !env.has_testmod) {
+ test__skip();
+ continue;
+ }
+
if (test_case->setup) {
err = test_case->setup(test_case);
if (CHECK(err, "test_setup", "test #%d setup failed: %d\n", i, err))
@@ -790,13 +844,11 @@ void test_core_reloc(void)
test_case->bpf_obj_file, PTR_ERR(obj)))
continue;
- /* for typed raw tracepoints, NULL should be specified */
- if (test_case->direct_raw_tp) {
- probe_name = "tp_btf/sys_enter";
- tp_name = NULL;
- } else {
- probe_name = "raw_tracepoint/sys_enter";
- tp_name = "sys_enter";
+ probe_name = "raw_tracepoint/sys_enter";
+ tp_name = "sys_enter";
+ if (test_case->prog_sec_name) {
+ probe_name = test_case->prog_sec_name;
+ tp_name = test_case->raw_tp_name; /* NULL for tp_btf */
}
prog = bpf_object__find_program_by_title(obj, probe_name);
@@ -837,7 +889,12 @@ void test_core_reloc(void)
goto cleanup;
/* trigger test run */
- usleep(1);
+ if (test_case->trigger) {
+ if (!ASSERT_OK(test_case->trigger(test_case), "test_trigger"))
+ goto cleanup;
+ } else {
+ usleep(1);
+ }
if (data->skip) {
test__skip();
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index e6e616cb7bc9..9a2850850121 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -15,6 +15,23 @@ struct core_reloc_kernel_output {
int comm_len;
};
+/*
+ * MODULE
+ */
+
+struct core_reloc_module_output {
+ long long len;
+ long long off;
+ int read_ctx_sz;
+ bool read_ctx_exists;
+ bool buf_exists;
+ bool len_exists;
+ bool off_exists;
+ /* we have test_progs[-flavor], so cut flavor part */
+ char comm[sizeof("test_progs")];
+ int comm_len;
+};
+
/*
* FLAVORS
*/
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_module.c b/tools/testing/selftests/bpf/progs/test_core_reloc_module.c
new file mode 100644
index 000000000000..d1840c1a9d36
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_module.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct bpf_testmod_test_read_ctx {
+ /* field order is mixed up */
+ size_t len;
+ char *buf;
+ loff_t off;
+} __attribute__((preserve_access_index));
+
+struct {
+ char in[256];
+ char out[256];
+ bool skip;
+ uint64_t my_pid_tgid;
+} data = {};
+
+struct core_reloc_module_output {
+ long long len;
+ long long off;
+ int read_ctx_sz;
+ bool read_ctx_exists;
+ bool buf_exists;
+ bool len_exists;
+ bool off_exists;
+ /* we have test_progs[-flavor], so cut flavor part */
+ char comm[sizeof("test_progs")];
+ int comm_len;
+};
+
+SEC("raw_tp/bpf_testmod_test_read")
+int BPF_PROG(test_core_module,
+ struct task_struct *task,
+ struct bpf_testmod_test_read_ctx *read_ctx)
+{
+ struct core_reloc_module_output *out = (void *)&data.out;
+ __u64 pid_tgid = bpf_get_current_pid_tgid();
+ __u32 real_tgid = (__u32)(pid_tgid >> 32);
+ __u32 real_pid = (__u32)pid_tgid;
+
+ if (data.my_pid_tgid != pid_tgid)
+ return 0;
+
+ if (BPF_CORE_READ(task, pid) != real_pid || BPF_CORE_READ(task, tgid) != real_tgid)
+ return 0;
+
+ out->len = BPF_CORE_READ(read_ctx, len);
+ out->off = BPF_CORE_READ(read_ctx, off);
+
+ out->read_ctx_sz = bpf_core_type_size(struct bpf_testmod_test_read_ctx);
+ out->read_ctx_exists = bpf_core_type_exists(struct bpf_testmod_test_read_ctx);
+ out->buf_exists = bpf_core_field_exists(read_ctx->buf);
+ out->off_exists = bpf_core_field_exists(read_ctx->off);
+ out->len_exists = bpf_core_field_exists(read_ctx->len);
+
+ out->comm_len = BPF_CORE_READ_STR_INTO(&out->comm, task, comm);
+
+ return 0;
+}
--
2.24.1
