selftests/bpf: Add test for BPF trampoline

Add sanity test for BPF trampoline that checks kernel functions
with up to 6 arguments of different sizes.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-10-ast@kernel.org

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 0c7d282..c63ab1a 100644 (file)
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -44,4 +44,17 @@ enum libbpf_pin_type {
        LIBBPF_PIN_BY_NAME,
 };
 
+/* The following types should be used by BPF_PROG_TYPE_TRACING program to
+ * access kernel function arguments. BPF trampoline and raw tracepoints
+ * typecast arguments to 'unsigned long long'.
+ */
+typedef int __attribute__((aligned(8))) ks32;
+typedef char __attribute__((aligned(8))) ks8;
+typedef short __attribute__((aligned(8))) ks16;
+typedef long long __attribute__((aligned(8))) ks64;
+typedef unsigned int __attribute__((aligned(8))) ku32;
+typedef unsigned char __attribute__((aligned(8))) ku8;
+typedef unsigned short __attribute__((aligned(8))) ku16;
+typedef unsigned long long __attribute__((aligned(8))) ku64;
+
 #endif

diff --git a/tools/testing/selftests/bpf/prog_tests/fentry_test.c b/tools/testing/selftests/bpf/prog_tests/fentry_test.c
new file mode 100644 (file)
index 0000000..9fb1031
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/fentry_test.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook */
+#include <test_progs.h>
+
+void test_fentry_test(void)
+{
+       struct bpf_prog_load_attr attr = {
+               .file = "./fentry_test.o",
+       };
+
+       char prog_name[] = "fentry/bpf_fentry_testX";
+       struct bpf_object *obj = NULL, *pkt_obj;
+       int err, pkt_fd, kfree_skb_fd, i;
+       struct bpf_link *link[6] = {};
+       struct bpf_program *prog[6];
+       __u32 duration, retval;
+       struct bpf_map *data_map;
+       const int zero = 0;
+       u64 result[6];
+
+       err = bpf_prog_load("./test_pkt_access.o", BPF_PROG_TYPE_SCHED_CLS,
+                           &pkt_obj, &pkt_fd);
+       if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
+               return;
+       err = bpf_prog_load_xattr(&attr, &obj, &kfree_skb_fd);
+       if (CHECK(err, "prog_load fail", "err %d errno %d\n", err, errno))
+               goto close_prog;
+
+       for (i = 0; i < 6; i++) {
+               prog_name[sizeof(prog_name) - 2] = '1' + i;
+               prog[i] = bpf_object__find_program_by_title(obj, prog_name);
+               if (CHECK(!prog[i], "find_prog", "prog %s not found\n", prog_name))
+                       goto close_prog;
+               link[i] = bpf_program__attach_trace(prog[i]);
+               if (CHECK(IS_ERR(link[i]), "attach_trace", "failed to link\n"))
+                       goto close_prog;
+       }
+       data_map = bpf_object__find_map_by_name(obj, "fentry_t.bss");
+       if (CHECK(!data_map, "find_data_map", "data map not found\n"))
+               goto close_prog;
+
+       err = bpf_prog_test_run(pkt_fd, 1, &pkt_v6, sizeof(pkt_v6),
+                               NULL, NULL, &retval, &duration);
+       CHECK(err || retval, "ipv6",
+             "err %d errno %d retval %d duration %d\n",
+             err, errno, retval, duration);
+
+       err = bpf_map_lookup_elem(bpf_map__fd(data_map), &zero, &result);
+       if (CHECK(err, "get_result",
+                 "failed to get output data: %d\n", err))
+               goto close_prog;
+
+       for (i = 0; i < 6; i++)
+               if (CHECK(result[i] != 1, "result", "bpf_fentry_test%d failed err %ld\n",
+                         i + 1, result[i]))
+                       goto close_prog;
+
+close_prog:
+       for (i = 0; i < 6; i++)
+               if (!IS_ERR_OR_NULL(link[i]))
+                       bpf_link__destroy(link[i]);
+       bpf_object__close(obj);
+       bpf_object__close(pkt_obj);
+}

diff --git a/tools/testing/selftests/bpf/progs/fentry_test.c b/tools/testing/selftests/bpf/progs/fentry_test.c
new file mode 100644 (file)
index 0000000..545788b
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/fentry_test.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook */
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+char _license[] SEC("license") = "GPL";
+
+struct test1 {
+       ks32 a;
+};
+static volatile __u64 test1_result;
+SEC("fentry/bpf_fentry_test1")
+int test1(struct test1 *ctx)
+{
+       test1_result = ctx->a == 1;
+       return 0;
+}
+
+struct test2 {
+       ks32 a;
+       ku64 b;
+};
+static volatile __u64 test2_result;
+SEC("fentry/bpf_fentry_test2")
+int test2(struct test2 *ctx)
+{
+       test2_result = ctx->a == 2 && ctx->b == 3;
+       return 0;
+}
+
+struct test3 {
+       ks8 a;
+       ks32 b;
+       ku64 c;
+};
+static volatile __u64 test3_result;
+SEC("fentry/bpf_fentry_test3")
+int test3(struct test3 *ctx)
+{
+       test3_result = ctx->a == 4 && ctx->b == 5 && ctx->c == 6;
+       return 0;
+}
+
+struct test4 {
+       void *a;
+       ks8 b;
+       ks32 c;
+       ku64 d;
+};
+static volatile __u64 test4_result;
+SEC("fentry/bpf_fentry_test4")
+int test4(struct test4 *ctx)
+{
+       test4_result = ctx->a == (void *)7 && ctx->b == 8 && ctx->c == 9 &&
+               ctx->d == 10;
+       return 0;
+}
+
+struct test5 {
+       ku64 a;
+       void *b;
+       ks16 c;
+       ks32 d;
+       ku64 e;
+};
+static volatile __u64 test5_result;
+SEC("fentry/bpf_fentry_test5")
+int test5(struct test5 *ctx)
+{
+       test5_result = ctx->a == 11 && ctx->b == (void *)12 && ctx->c == 13 &&
+               ctx->d == 14 && ctx->e == 15;
+       return 0;
+}
+
+struct test6 {
+       ku64 a;
+       void *b;
+       ks16 c;
+       ks32 d;
+       void *e;
+       ks64 f;
+};
+static volatile __u64 test6_result;
+SEC("fentry/bpf_fentry_test6")
+int test6(struct test6 *ctx)
+{
+       test6_result = ctx->a == 16 && ctx->b == (void *)17 && ctx->c == 18 &&
+               ctx->d == 19 && ctx->e == (void *)20 && ctx->f == 21;
+       return 0;
+}