1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ 3 4 #include <vmlinux.h> 5 #include <bpf/bpf_helpers.h> 6 #include "uptr_test_common.h" 7 8 struct task_struct *bpf_task_from_pid(s32 pid) __ksym; 9 void bpf_task_release(struct task_struct *p) __ksym; 10 void bpf_cgroup_release(struct cgroup *cgrp) __ksym; 11 12 struct { 13 __uint(type, BPF_MAP_TYPE_TASK_STORAGE); 14 __uint(map_flags, BPF_F_NO_PREALLOC); 15 __type(key, int); 16 __type(value, struct value_type); 17 } datamap SEC(".maps"); 18 19 pid_t target_pid = 0; 20 pid_t parent_pid = 0; 21 22 SEC("tp_btf/sys_enter") 23 int on_enter(__u64 *ctx) 24 { 25 struct task_struct *task, *data_task; 26 struct value_type *ptr; 27 struct user_data *udata; 28 struct cgroup *cgrp; 29 30 task = bpf_get_current_task_btf(); 31 if (task->pid != target_pid) 32 return 0; 33 34 data_task = bpf_task_from_pid(parent_pid); 35 if (!data_task) 36 return 0; 37 38 ptr = bpf_task_storage_get(&datamap, data_task, 0, 0); 39 bpf_task_release(data_task); 40 if (!ptr) 41 return 0; 42 43 cgrp = bpf_kptr_xchg(&ptr->cgrp, NULL); 44 if (cgrp) { 45 int lvl = cgrp->level; 46 47 bpf_cgroup_release(cgrp); 48 return lvl; 49 } 50 51 udata = ptr->udata; 52 if (!udata || udata->result) 53 return 0; 54 udata->result = MAGIC_VALUE + udata->a + udata->b; 55 56 udata = ptr->nested.udata; 57 if (udata && !udata->nested_result) 58 udata->nested_result = udata->result; 59 60 return 0; 61 } 62 63 char _license[] SEC("license") = "GPL"; 64