// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ #include <vmlinux.h> #include <bpf/bpf_tracing.h> #include "bpf_misc.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; /* If dead code elimination kicks in, the increment +=2 will be * removed. For raw_tp programs attaching to tracepoints in kernel * modules, we mark input arguments as PTR_MAYBE_NULL, so branch * prediction should never kick in. */ asm volatile ("%[i] += 1; if %[ctx] != 0 goto +1; %[i] += 2;" : [i]"+r"(i) : [ctx]"r"(skb) : "memory"); return 0; }