1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ 3 4 #include <vmlinux.h> 5 #include <string.h> 6 #include <stdbool.h> 7 #include <bpf/bpf_helpers.h> 8 #include <bpf/bpf_tracing.h> 9 #include "bpf_misc.h" 10 #include "errno.h" 11 12 char _license[] SEC("license") = "GPL"; 13 14 const void *user_ptr = NULL; 15 16 struct elem { 17 char data[128]; 18 struct bpf_task_work tw; 19 }; 20 21 struct { 22 __uint(type, BPF_MAP_TYPE_HASH); 23 __uint(map_flags, BPF_F_NO_PREALLOC); 24 __uint(max_entries, 1); 25 __type(key, int); 26 __type(value, struct elem); 27 } hmap SEC(".maps"); 28 29 struct { 30 __uint(type, BPF_MAP_TYPE_ARRAY); 31 __uint(max_entries, 1); 32 __type(key, int); 33 __type(value, struct elem); 34 } arrmap SEC(".maps"); 35 36 struct { 37 __uint(type, BPF_MAP_TYPE_LRU_HASH); 38 __uint(max_entries, 1); 39 __type(key, int); 40 __type(value, struct elem); 41 } lrumap SEC(".maps"); 42 43 static int process_work(struct bpf_map *map, void *key, void *value) 44 { 45 struct elem *work = value; 46 47 bpf_copy_from_user_str(work->data, sizeof(work->data), (const void *)user_ptr, 0); 48 return 0; 49 } 50 51 int key = 0; 52 53 SEC("perf_event") 54 int oncpu_hash_map(struct pt_regs *args) 55 { 56 struct elem empty_work = { .data = { 0 } }; 57 struct elem *work; 58 struct task_struct *task; 59 int err; 60 61 task = bpf_get_current_task_btf(); 62 err = bpf_map_update_elem(&hmap, &key, &empty_work, BPF_NOEXIST); 63 if (err) 64 return 0; 65 work = bpf_map_lookup_elem(&hmap, &key); 66 if (!work) 67 return 0; 68 69 bpf_task_work_schedule_resume(task, &work->tw, &hmap, process_work, NULL); 70 return 0; 71 } 72 73 SEC("perf_event") 74 int oncpu_array_map(struct pt_regs *args) 75 { 76 struct elem *work; 77 struct task_struct *task; 78 79 task = bpf_get_current_task_btf(); 80 work = bpf_map_lookup_elem(&arrmap, &key); 81 if (!work) 82 return 0; 83 bpf_task_work_schedule_signal(task, &work->tw, &arrmap, process_work, NULL); 84 return 0; 85 } 86 87 SEC("perf_event") 88 int oncpu_lru_map(struct pt_regs *args) 89 { 90 struct elem empty_work = { .data = { 0 } }; 91 struct elem *work; 92 struct task_struct *task; 93 int err; 94 95 task = bpf_get_current_task_btf(); 96 work = bpf_map_lookup_elem(&lrumap, &key); 97 if (work) 98 return 0; 99 err = bpf_map_update_elem(&lrumap, &key, &empty_work, BPF_NOEXIST); 100 if (err) 101 return 0; 102 work = bpf_map_lookup_elem(&lrumap, &key); 103 if (!work || work->data[0]) 104 return 0; 105 bpf_task_work_schedule_resume(task, &work->tw, &lrumap, process_work, NULL); 106 return 0; 107 } 108