selftest/bpf: The test cases of BPF cookie for fentry/fexit/fmod_ret/lsm.

Make sure BPF cookies are correct for fentry/fexit/fmod_ret/lsm.

Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220510205923.3206889-6-kuifeng@fb.com

tools/testing/selftests/bpf/prog_tests/bpf_cookie.c

@@ -4,8 +4,11 @@
 #include <pthread.h>
 #include <sched.h>
 #include <sys/syscall.h>
+#include <sys/mman.h>
 #include <unistd.h>
 #include <test_progs.h>
+#include <network_helpers.h>
+#include <bpf/btf.h>
 #include "test_bpf_cookie.skel.h"
 #include "kprobe_multi.skel.h"
 
@@ -410,6 +413,88 @@ cleanup:
 	bpf_link__destroy(link);
 }
 
+static void tracing_subtest(struct test_bpf_cookie *skel)
+{
+	__u64 cookie;
+	int prog_fd;
+	int fentry_fd = -1, fexit_fd = -1, fmod_ret_fd = -1;
+	LIBBPF_OPTS(bpf_test_run_opts, opts);
+	LIBBPF_OPTS(bpf_link_create_opts, link_opts);
+
+	skel->bss->fentry_res = 0;
+	skel->bss->fexit_res = 0;
+
+	cookie = 0x10000000000000L;
+	prog_fd = bpf_program__fd(skel->progs.fentry_test1);
+	link_opts.tracing.cookie = cookie;
+	fentry_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_FENTRY, &link_opts);
+	if (!ASSERT_GE(fentry_fd, 0, "fentry.link_create"))
+		goto cleanup;
+
+	cookie = 0x20000000000000L;
+	prog_fd = bpf_program__fd(skel->progs.fexit_test1);
+	link_opts.tracing.cookie = cookie;
+	fexit_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_FEXIT, &link_opts);
+	if (!ASSERT_GE(fexit_fd, 0, "fexit.link_create"))
+		goto cleanup;
+
+	cookie = 0x30000000000000L;
+	prog_fd = bpf_program__fd(skel->progs.fmod_ret_test);
+	link_opts.tracing.cookie = cookie;
+	fmod_ret_fd = bpf_link_create(prog_fd, 0, BPF_MODIFY_RETURN, &link_opts);
+	if (!ASSERT_GE(fmod_ret_fd, 0, "fmod_ret.link_create"))
+		goto cleanup;
+
+	prog_fd = bpf_program__fd(skel->progs.fentry_test1);
+	bpf_prog_test_run_opts(prog_fd, &opts);
+
+	prog_fd = bpf_program__fd(skel->progs.fmod_ret_test);
+	bpf_prog_test_run_opts(prog_fd, &opts);
+
+	ASSERT_EQ(skel->bss->fentry_res, 0x10000000000000L, "fentry_res");
+	ASSERT_EQ(skel->bss->fexit_res, 0x20000000000000L, "fexit_res");
+	ASSERT_EQ(skel->bss->fmod_ret_res, 0x30000000000000L, "fmod_ret_res");
+
+cleanup:
+	if (fentry_fd >= 0)
+		close(fentry_fd);
+	if (fexit_fd >= 0)
+		close(fexit_fd);
+	if (fmod_ret_fd >= 0)
+		close(fmod_ret_fd);
+}
+
+int stack_mprotect(void);
+
+static void lsm_subtest(struct test_bpf_cookie *skel)
+{
+	__u64 cookie;
+	int prog_fd;
+	int lsm_fd = -1;
+	LIBBPF_OPTS(bpf_link_create_opts, link_opts);
+
+	skel->bss->lsm_res = 0;
+
+	cookie = 0x90000000000090L;
+	prog_fd = bpf_program__fd(skel->progs.test_int_hook);
+	link_opts.tracing.cookie = cookie;
+	lsm_fd = bpf_link_create(prog_fd, 0, BPF_LSM_MAC, &link_opts);
+	if (!ASSERT_GE(lsm_fd, 0, "lsm.link_create"))
+		goto cleanup;
+
+	stack_mprotect();
+	if (!ASSERT_EQ(errno, EPERM, "stack_mprotect"))
+		goto cleanup;
+
+	usleep(1);
+
+	ASSERT_EQ(skel->bss->lsm_res, 0x90000000000090L, "fentry_res");
+
+cleanup:
+	if (lsm_fd >= 0)
+		close(lsm_fd);
+}
+
 void test_bpf_cookie(void)
 {
 	struct test_bpf_cookie *skel;
@@ -432,6 +517,10 @@ void test_bpf_cookie(void)
 		tp_subtest(skel);
 	if (test__start_subtest("perf_event"))
 		pe_subtest(skel);
+	if (test__start_subtest("trampoline"))
+		tracing_subtest(skel);
+	if (test__start_subtest("lsm"))
+		lsm_subtest(skel);
 
 	test_bpf_cookie__destroy(skel);
 }

tools/testing/selftests/bpf/progs/test_bpf_cookie.c

@@ -4,18 +4,23 @@
 #include "vmlinux.h"
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
+#include <errno.h>
 
 int my_tid;
 
-int kprobe_res;
-int kprobe_multi_res;
-int kretprobe_res;
-int uprobe_res;
-int uretprobe_res;
-int tp_res;
-int pe_res;
+__u64 kprobe_res;
+__u64 kprobe_multi_res;
+__u64 kretprobe_res;
+__u64 uprobe_res;
+__u64 uretprobe_res;
+__u64 tp_res;
+__u64 pe_res;
+__u64 fentry_res;
+__u64 fexit_res;
+__u64 fmod_ret_res;
+__u64 lsm_res;
 
-static void update(void *ctx, int *res)
+static void update(void *ctx, __u64 *res)
 {
 	if (my_tid != (u32)bpf_get_current_pid_tgid())
 		return;
@@ -82,4 +87,35 @@ int handle_pe(struct pt_regs *ctx)
 	return 0;
 }
 
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(fentry_test1, int a)
+{
+	update(ctx, &fentry_res);
+	return 0;
+}
+
+SEC("fexit/bpf_fentry_test1")
+int BPF_PROG(fexit_test1, int a, int ret)
+{
+	update(ctx, &fexit_res);
+	return 0;
+}
+
+SEC("fmod_ret/bpf_modify_return_test")
+int BPF_PROG(fmod_ret_test, int _a, int *_b, int _ret)
+{
+	update(ctx, &fmod_ret_res);
+	return 1234;
+}
+
+SEC("lsm/file_mprotect")
+int BPF_PROG(test_int_hook, struct vm_area_struct *vma,
+	     unsigned long reqprot, unsigned long prot, int ret)
+{
+	if (my_tid != (u32)bpf_get_current_pid_tgid())
+		return ret;
+	update(ctx, &lsm_res);
+	return -EPERM;
+}
+
 char _license[] SEC("license") = "GPL";