// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <errno.h>

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

__u64 test1_result = 0;
SEC("fentry/bpf_fentry_test1")
int BPF_PROG(test1)
{
        __u64 cnt = bpf_get_func_arg_cnt(ctx);
        __u64 a = 0, z = 0, ret = 0;
        __s64 err;

        test1_result = cnt == 1;

        /* valid arguments */
        err = bpf_get_func_arg(ctx, 0, &a);

        /* We need to cast access to traced function argument values with
         * proper type cast, because trampoline uses type specific instruction
         * to save it, like for 'int a' with 32-bit mov like:
         *
         *   mov %edi,-0x8(%rbp)
         *
         * so the upper 4 bytes are not zeroed.
         */
        test1_result &= err == 0 && ((int) a == 1);

        /* not valid argument */
        err = bpf_get_func_arg(ctx, 1, &z);
        test1_result &= err == -EINVAL;

        /* return value fails in fentry */
        err = bpf_get_func_ret(ctx, &ret);
        test1_result &= err == -EOPNOTSUPP;
        return 0;
}

__u64 test2_result = 0;
SEC("fexit/bpf_fentry_test2")
int BPF_PROG(test2)
{
        __u64 cnt = bpf_get_func_arg_cnt(ctx);
        __u64 a = 0, b = 0, z = 0, ret = 0;
        __s64 err;

        test2_result = cnt == 2;

        /* valid arguments */
        err = bpf_get_func_arg(ctx, 0, &a);
        test2_result &= err == 0 && (int) a == 2;

        err = bpf_get_func_arg(ctx, 1, &b);
        test2_result &= err == 0 && b == 3;

        /* not valid argument */
        err = bpf_get_func_arg(ctx, 2, &z);
        test2_result &= err == -EINVAL;

        /* return value */
        err = bpf_get_func_ret(ctx, &ret);
        test2_result &= err == 0 && ret == 5;
        return 0;
}

__u64 test3_result = 0;
SEC("fmod_ret/bpf_modify_return_test")
int BPF_PROG(fmod_ret_test, int _a, int *_b, int _ret)
{
        __u64 cnt = bpf_get_func_arg_cnt(ctx);
        __u64 a = 0, b = 0, z = 0, ret = 0;
        __s64 err;

        test3_result = cnt == 2;

        /* valid arguments */
        err = bpf_get_func_arg(ctx, 0, &a);
        test3_result &= err == 0 && ((int) a == 1);

        err = bpf_get_func_arg(ctx, 1, &b);
        test3_result &= err == 0 && ((int *) b == _b);

        /* not valid argument */
        err = bpf_get_func_arg(ctx, 2, &z);
        test3_result &= err == -EINVAL;

        /* return value */
        err = bpf_get_func_ret(ctx, &ret);
        test3_result &= err == 0 && ret == 0;

        /* change return value, it's checked in fexit_test program */
        return 1234;
}

__u64 test4_result = 0;
SEC("fexit/bpf_modify_return_test")
int BPF_PROG(fexit_test, int _a, int *_b, int _ret)
{
        __u64 cnt = bpf_get_func_arg_cnt(ctx);
        __u64 a = 0, b = 0, z = 0, ret = 0;
        __s64 err;

        test4_result = cnt == 2;

        /* valid arguments */
        err = bpf_get_func_arg(ctx, 0, &a);
        test4_result &= err == 0 && ((int) a == 1);

        err = bpf_get_func_arg(ctx, 1, &b);
        test4_result &= err == 0 && ((int *) b == _b);

        /* not valid argument */
        err = bpf_get_func_arg(ctx, 2, &z);
        test4_result &= err == -EINVAL;

        /* return value */
        err = bpf_get_func_ret(ctx, &ret);
        test4_result &= err == 0 && ret == 1234;
        return 0;
}

__u64 test5_result = 0;
SEC("tp_btf/bpf_testmod_fentry_test1_tp")
int BPF_PROG(tp_test1)
{
        __u64 cnt = bpf_get_func_arg_cnt(ctx);
        __u64 a = 0, z = 0;
        __s64 err;

        test5_result = cnt == 1;

        err = bpf_get_func_arg(ctx, 0, &a);
        test5_result &= err == 0 && ((int) a == 1);

        /* not valid argument */
        err = bpf_get_func_arg(ctx, 1, &z);
        test5_result &= err == -EINVAL;

        return 0;
}

__u64 test6_result = 0;
SEC("tp_btf/bpf_testmod_fentry_test2_tp")
int BPF_PROG(tp_test2)
{
        __u64 cnt = bpf_get_func_arg_cnt(ctx);
        __u64 a = 0, b = 0, z = 0;
        __s64 err;

        test6_result = cnt == 2;

        /* valid arguments */
        err = bpf_get_func_arg(ctx, 0, &a);
        test6_result &= err == 0 && (int) a == 2;

        err = bpf_get_func_arg(ctx, 1, &b);
        test6_result &= err == 0 && b == 3;

        /* not valid argument */
        err = bpf_get_func_arg(ctx, 2, &z);
        test6_result &= err == -EINVAL;

        return 0;
}

__u64 test7_result = 0;
#if defined(bpf_target_x86) || defined(bpf_target_arm64) || defined(bpf_target_riscv)
SEC("fsession/bpf_fentry_test1")
int BPF_PROG(test7)
{
        __u64 cnt = bpf_get_func_arg_cnt(ctx);
        __u64 a = 0, z = 0, ret = 0;
        __s64 err;

        test7_result = cnt == 1;

        /* valid arguments */
        err = bpf_get_func_arg(ctx, 0, &a);
        test7_result &= err == 0 && ((int) a == 1);

        /* not valid argument */
        err = bpf_get_func_arg(ctx, 1, &z);
        test7_result &= err == -EINVAL;

        if (bpf_session_is_return(ctx)) {
                err = bpf_get_func_ret(ctx, &ret);
                test7_result &= err == 0 && ret == 2;
        } else {
                err = bpf_get_func_ret(ctx, &ret);
                test7_result &= err == 0 && ret == 0;
        }

        return 0;
}
#else
SEC("fentry/bpf_fentry_test1")
int BPF_PROG(test7)
{
        test7_result = 1;
        return 0;
}
#endif