// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ #include <vmlinux.h> #include <bpf/bpf_helpers.h> #include "uptr_test_common.h" struct task_struct *bpf_task_from_pid(s32 pid) __ksym; void bpf_task_release(struct task_struct *p) __ksym; void bpf_cgroup_release(struct cgroup *cgrp) __ksym; struct { __uint(type, BPF_MAP_TYPE_TASK_STORAGE); __uint(map_flags, BPF_F_NO_PREALLOC); __type(key, int); __type(value, struct value_type); } datamap SEC(".maps"); pid_t target_pid = 0; pid_t parent_pid = 0; SEC("tp_btf/sys_enter") int on_enter(__u64 *ctx) { struct task_struct *task, *data_task; struct value_type *ptr; struct user_data *udata; struct cgroup *cgrp; task = bpf_get_current_task_btf(); if (task->pid != target_pid) return 0; data_task = bpf_task_from_pid(parent_pid); if (!data_task) return 0; ptr = bpf_task_storage_get(&datamap, data_task, 0, 0); bpf_task_release(data_task); if (!ptr) return 0; cgrp = bpf_kptr_xchg(&ptr->cgrp, NULL); if (cgrp) { int lvl = cgrp->level; bpf_cgroup_release(cgrp); return lvl; } udata = ptr->udata; if (!udata || udata->result) return 0; udata->result = MAGIC_VALUE + udata->a + udata->b; udata = ptr->nested.udata; if (udata && !udata->nested_result) udata->nested_result = udata->result; return 0; } char _license[] SEC("license") = "GPL";