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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
char _license[] SEC("license") = "GPL";
int tid;
int i;
SEC("tp_btf/bpf_testmod_test_raw_tp_null")
int BPF_PROG(test_raw_tp_null, struct sk_buff *skb)
{
struct task_struct *task = bpf_get_current_task_btf();
if (task->pid != tid)
return 0;
i = i + skb->mark + 1;
/* The compiler may move the NULL check before this deref, which causes
* the load to fail as deref of scalar. Prevent that by using a barrier.
*/
barrier();
/* If dead code elimination kicks in, the increment below will
* be removed. For raw_tp programs, we mark input arguments as
* PTR_MAYBE_NULL, so branch prediction should never kick in.
*/
if (!skb)
i += 2;
return 0;
}
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