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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
char _license[] SEC("license") = "GPL";
struct callback_ctx {
int output;
};
/* These should be set by the user program */
u32 nested_callback_nr_loops;
u32 stop_index = -1;
u32 nr_loops;
int pid;
/* Making these global variables so that the userspace program
* can verify the output through the skeleton
*/
int nr_loops_returned;
int g_output;
int err;
static int callback(__u32 index, void *data)
{
struct callback_ctx *ctx = data;
if (index >= stop_index)
return 1;
ctx->output += index;
return 0;
}
static int empty_callback(__u32 index, void *data)
{
return 0;
}
static int nested_callback2(__u32 index, void *data)
{
nr_loops_returned += bpf_loop(nested_callback_nr_loops, callback, data, 0);
return 0;
}
static int nested_callback1(__u32 index, void *data)
{
bpf_loop(nested_callback_nr_loops, nested_callback2, data, 0);
return 0;
}
SEC("fentry/__x64_sys_nanosleep")
int test_prog(void *ctx)
{
struct callback_ctx data = {};
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
nr_loops_returned = bpf_loop(nr_loops, callback, &data, 0);
if (nr_loops_returned < 0)
err = nr_loops_returned;
else
g_output = data.output;
return 0;
}
SEC("fentry/__x64_sys_nanosleep")
int prog_null_ctx(void *ctx)
{
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
nr_loops_returned = bpf_loop(nr_loops, empty_callback, NULL, 0);
return 0;
}
SEC("fentry/__x64_sys_nanosleep")
int prog_invalid_flags(void *ctx)
{
struct callback_ctx data = {};
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
err = bpf_loop(nr_loops, callback, &data, 1);
return 0;
}
SEC("fentry/__x64_sys_nanosleep")
int prog_nested_calls(void *ctx)
{
struct callback_ctx data = {};
if (bpf_get_current_pid_tgid() >> 32 != pid)
return 0;
nr_loops_returned = 0;
bpf_loop(nr_loops, nested_callback1, &data, 0);
g_output = data.output;
return 0;
}
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