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

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/prog_tests/modify_return.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/prog_tests/modify_return.c
Extension
.c
Size
1722 bytes
Lines
64
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0

/*
 * Copyright 2020 Google LLC.
 */

#include <test_progs.h>
#include <unistd.h>
#include "modify_return.skel.h"

#define LOWER(x) ((x) & 0xffff)
#define UPPER(x) ((x) >> 16)


static void run_test(__u32 input_retval, __u16 want_side_effect, __s16 want_ret)
{
	struct modify_return *skel = NULL;
	int err, prog_fd;
	__u16 side_effect;
	__s16 ret;
	LIBBPF_OPTS(bpf_test_run_opts, topts);

	skel = modify_return__open_and_load();
	if (!ASSERT_OK_PTR(skel, "skel_load"))
		goto cleanup;

	skel->bss->input_retval = input_retval;
	skel->bss->test_pid = getpid();

	err = modify_return__attach(skel);
	if (!ASSERT_OK(err, "modify_return__attach failed"))
		goto cleanup;

	prog_fd = bpf_program__fd(skel->progs.fmod_ret_test);
	err = bpf_prog_test_run_opts(prog_fd, &topts);
	ASSERT_OK(err, "test_run");

	side_effect = UPPER(topts.retval);
	ret = LOWER(topts.retval);

	ASSERT_EQ(ret, want_ret, "test_run ret");
	ASSERT_EQ(side_effect, want_side_effect, "modify_return side_effect");
	ASSERT_EQ(skel->bss->fentry_result, 1, "modify_return fentry_result");
	ASSERT_EQ(skel->bss->fexit_result, 1, "modify_return fexit_result");
	ASSERT_EQ(skel->bss->fmod_ret_result, 1, "modify_return fmod_ret_result");

	ASSERT_EQ(skel->bss->fentry_result2, 1, "modify_return fentry_result2");
	ASSERT_EQ(skel->bss->fexit_result2, 1, "modify_return fexit_result2");
	ASSERT_EQ(skel->bss->fmod_ret_result2, 1, "modify_return fmod_ret_result2");

cleanup:
	modify_return__destroy(skel);
}

void test_modify_return(void)
{
	run_test(0 /* input_retval */,
		 2 /* want_side_effect */,
		 33 /* want_ret */);
	run_test(-EINVAL /* input_retval */,
		 0 /* want_side_effect */,
		 -EINVAL * 2 /* want_ret */);
}

Annotation

Implementation Notes