Commit a3a51133 authored by Jiri Olsa's avatar Jiri Olsa Committed by Andrii Nakryiko
Browse files

selftests/bpf: Add kprobe session cookie test 



Adding kprobe session test that verifies the cookie value
get properly propagated from entry to return program.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-8-jolsa@kernel.org
parent 0983b169

tools/testing/selftests/bpf/bpf_kfuncs.h

+1 −0
Original line number Diff line number Diff line
@@ -77,4 +77,5 @@ extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr, 
				      struct bpf_key *trusted_keyring) __ksym;



extern bool bpf_session_is_return(void) __ksym __weak;

extern long *bpf_session_cookie(void) __ksym __weak;

#endif

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

+35 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include "kprobe_multi_empty.skel.h"

#include "kprobe_multi_override.skel.h"

#include "kprobe_multi_session.skel.h"

#include "kprobe_multi_session_cookie.skel.h"

#include "bpf/libbpf_internal.h"

#include "bpf/hashmap.h"
@@ -363,6 +364,38 @@ static void test_session_skel_api(void) 
	kprobe_multi_session__destroy(skel);

}



static void test_session_cookie_skel_api(void)

{

	struct kprobe_multi_session_cookie *skel = NULL;

	LIBBPF_OPTS(bpf_kprobe_multi_opts, opts);

	LIBBPF_OPTS(bpf_test_run_opts, topts);

	struct bpf_link *link = NULL;

	int err, prog_fd;



	skel = kprobe_multi_session_cookie__open_and_load();

	if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load"))

		return;



	skel->bss->pid = getpid();



	err = kprobe_multi_session_cookie__attach(skel);

	if (!ASSERT_OK(err, " kprobe_multi_wrapper__attach"))

		goto cleanup;



	prog_fd = bpf_program__fd(skel->progs.trigger);

	err = bpf_prog_test_run_opts(prog_fd, &topts);

	ASSERT_OK(err, "test_run");

	ASSERT_EQ(topts.retval, 0, "test_run");



	ASSERT_EQ(skel->bss->test_kprobe_1_result, 1, "test_kprobe_1_result");

	ASSERT_EQ(skel->bss->test_kprobe_2_result, 2, "test_kprobe_2_result");

	ASSERT_EQ(skel->bss->test_kprobe_3_result, 3, "test_kprobe_3_result");



cleanup:

	bpf_link__destroy(link);

	kprobe_multi_session_cookie__destroy(skel);

}



static size_t symbol_hash(long key, void *ctx __maybe_unused)

{

	return str_hash((const char *) key);
@@ -729,4 +762,6 @@ void test_kprobe_multi_test(void) 
		test_attach_override();

	if (test__start_subtest("session"))

		test_session_skel_api();

	if (test__start_subtest("session_cookie"))

		test_session_cookie_skel_api();

}

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

0 → 100644
+58 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include <stdbool.h>

#include "bpf_kfuncs.h"



char _license[] SEC("license") = "GPL";



int pid = 0;



__u64 test_kprobe_1_result = 0;

__u64 test_kprobe_2_result = 0;

__u64 test_kprobe_3_result = 0;



/*

 * No tests in here, just to trigger 'bpf_fentry_test*'

 * through tracing test_run

 */

SEC("fentry/bpf_modify_return_test")

int BPF_PROG(trigger)

{

	return 0;

}



static int check_cookie(__u64 val, __u64 *result)

{

	long *cookie;



	if (bpf_get_current_pid_tgid() >> 32 != pid)

		return 1;



	cookie = bpf_session_cookie();



	if (bpf_session_is_return())

		*result = *cookie == val ? val : 0;

	else

		*cookie = val;

	return 0;

}



SEC("kprobe.session/bpf_fentry_test1")

int test_kprobe_1(struct pt_regs *ctx)

{

	return check_cookie(1, &test_kprobe_1_result);

}



SEC("kprobe.session/bpf_fentry_test1")

int test_kprobe_2(struct pt_regs *ctx)

{

	return check_cookie(2, &test_kprobe_2_result);

}



SEC("kprobe.session/bpf_fentry_test1")

int test_kprobe_3(struct pt_regs *ctx)

{

	return check_cookie(3, &test_kprobe_3_result);

}