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// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.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;
}
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