Merge branch 'bpf-raw-tracepoint-support-for-bpf-cookie'

Andrii Nakryiko says:

====================
BPF raw tracepoint support for BPF cookie

Add ability to specify and retrieve BPF cookie for raw tracepoint programs.
Both BTF-aware (SEC("tp_btf")) and non-BTF-aware (SEC("raw_tp")) are
supported, as they are exactly the same at runtime.

This issue recently came up in production use cases, where custom tried to
switch from slower classic tracepoints to raw tracepoints and ran into this
limitation. Luckily, it's not that hard to support this for raw_tp programs.

v2->v3:
  - s/bpf_raw_tp_open/bpf_raw_tracepoint_open_opts/ (Alexei, Eduard);
v1->v2:
  - fixed type definition for stubs of bpf_probe_{register,unregister};
  - added __u32 :u32 and aligned raw_tp fields (Jiri);
  - added Stanislav's ack.
====================

Link: https://lore.kernel.org/r/20240319233852.1977493-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

2 files changed, 129 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
index 1454cebc262b..4407ea428e77 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c
@@ -573,6 +573,115 @@ cleanup:
 		close(lsm_fd);
 }
 
+static void tp_btf_subtest(struct test_bpf_cookie *skel)
+{
+	__u64 cookie;
+	int prog_fd, link_fd = -1;
+	struct bpf_link *link = NULL;
+	LIBBPF_OPTS(bpf_link_create_opts, link_opts);
+	LIBBPF_OPTS(bpf_raw_tp_opts, raw_tp_opts);
+	LIBBPF_OPTS(bpf_trace_opts, trace_opts);
+
+	/* There are three different ways to attach tp_btf (BTF-aware raw
+	 * tracepoint) programs. Let's test all of them.
+	 */
+	prog_fd = bpf_program__fd(skel->progs.handle_tp_btf);
+
+	/* low-level BPF_RAW_TRACEPOINT_OPEN command wrapper */
+	skel->bss->tp_btf_res = 0;
+
+	raw_tp_opts.cookie = cookie = 0x11000000000000L;
+	link_fd = bpf_raw_tracepoint_open_opts(prog_fd, &raw_tp_opts);
+	if (!ASSERT_GE(link_fd, 0, "bpf_raw_tracepoint_open_opts"))
+		goto cleanup;
+
+	usleep(1); /* trigger */
+	close(link_fd); /* detach */
+	link_fd = -1;
+
+	ASSERT_EQ(skel->bss->tp_btf_res, cookie, "raw_tp_open_res");
+
+	/* low-level generic bpf_link_create() API */
+	skel->bss->tp_btf_res = 0;
+
+	link_opts.tracing.cookie = cookie = 0x22000000000000L;
+	link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_RAW_TP, &link_opts);
+	if (!ASSERT_GE(link_fd, 0, "bpf_link_create"))
+		goto cleanup;
+
+	usleep(1); /* trigger */
+	close(link_fd); /* detach */
+	link_fd = -1;
+
+	ASSERT_EQ(skel->bss->tp_btf_res, cookie, "link_create_res");
+
+	/* high-level bpf_link-based bpf_program__attach_trace_opts() API */
+	skel->bss->tp_btf_res = 0;
+
+	trace_opts.cookie = cookie = 0x33000000000000L;
+	link = bpf_program__attach_trace_opts(skel->progs.handle_tp_btf, &trace_opts);
+	if (!ASSERT_OK_PTR(link, "attach_trace_opts"))
+		goto cleanup;
+
+	usleep(1); /* trigger */
+	bpf_link__destroy(link); /* detach */
+	link = NULL;
+
+	ASSERT_EQ(skel->bss->tp_btf_res, cookie, "attach_trace_opts_res");
+
+cleanup:
+	if (link_fd >= 0)
+		close(link_fd);
+	bpf_link__destroy(link);
+}
+
+static void raw_tp_subtest(struct test_bpf_cookie *skel)
+{
+	__u64 cookie;
+	int prog_fd, link_fd = -1;
+	struct bpf_link *link = NULL;
+	LIBBPF_OPTS(bpf_raw_tp_opts, raw_tp_opts);
+	LIBBPF_OPTS(bpf_raw_tracepoint_opts, opts);
+
+	/* There are two different ways to attach raw_tp programs */
+	prog_fd = bpf_program__fd(skel->progs.handle_raw_tp);
+
+	/* low-level BPF_RAW_TRACEPOINT_OPEN command wrapper */
+	skel->bss->raw_tp_res = 0;
+
+	raw_tp_opts.tp_name = "sys_enter";
+	raw_tp_opts.cookie = cookie = 0x55000000000000L;
+	link_fd = bpf_raw_tracepoint_open_opts(prog_fd, &raw_tp_opts);
+	if (!ASSERT_GE(link_fd, 0, "bpf_raw_tracepoint_open_opts"))
+		goto cleanup;
+
+	usleep(1); /* trigger */
+	close(link_fd); /* detach */
+	link_fd = -1;
+
+	ASSERT_EQ(skel->bss->raw_tp_res, cookie, "raw_tp_open_res");
+
+	/* high-level bpf_link-based bpf_program__attach_raw_tracepoint_opts() API */
+	skel->bss->raw_tp_res = 0;
+
+	opts.cookie = cookie = 0x66000000000000L;
+	link = bpf_program__attach_raw_tracepoint_opts(skel->progs.handle_raw_tp,
+						       "sys_enter", &opts);
+	if (!ASSERT_OK_PTR(link, "attach_raw_tp_opts"))
+		goto cleanup;
+
+	usleep(1); /* trigger */
+	bpf_link__destroy(link); /* detach */
+	link = NULL;
+
+	ASSERT_EQ(skel->bss->raw_tp_res, cookie, "attach_raw_tp_opts_res");
+
+cleanup:
+	if (link_fd >= 0)
+		close(link_fd);
+	bpf_link__destroy(link);
+}
+
 void test_bpf_cookie(void)
 {
 	struct test_bpf_cookie *skel;
@@ -601,6 +710,9 @@ void test_bpf_cookie(void)
 		tracing_subtest(skel);
 	if (test__start_subtest("lsm"))
 		lsm_subtest(skel);
-
+	if (test__start_subtest("tp_btf"))
+		tp_btf_subtest(skel);
+	if (test__start_subtest("raw_tp"))
+		raw_tp_subtest(skel);
 	test_bpf_cookie__destroy(skel);
 }
diff --git a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c
index 5a3a80f751c4..c83142b55f47 100644
--- a/tools/testing/selftests/bpf/progs/test_bpf_cookie.c
+++ b/tools/testing/selftests/bpf/progs/test_bpf_cookie.c
@@ -15,6 +15,8 @@ __u64 uprobe_res;
 __u64 uretprobe_res;
 __u64 tp_res;
 __u64 pe_res;
+__u64 raw_tp_res;
+__u64 tp_btf_res;
 __u64 fentry_res;
 __u64 fexit_res;
 __u64 fmod_ret_res;
@@ -87,6 +89,20 @@ int handle_pe(struct pt_regs *ctx)
 	return 0;
 }
 
+SEC("raw_tp/sys_enter")
+int handle_raw_tp(void *ctx)
+{
+	update(ctx, &raw_tp_res);
+	return 0;
+}
+
+SEC("tp_btf/sys_enter")
+int handle_tp_btf(void *ctx)
+{
+	update(ctx, &tp_btf_res);
+	return 0;
+}
+
 SEC("fentry/bpf_fentry_test1")
 int BPF_PROG(fentry_test1, int a)
 {