bpf/progs/task_ls_recursion.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* Copyright (c) 2021 Facebook */
0003
0004 #include "vmlinux.h"
0005 #include <bpf/bpf_helpers.h>
0006 #include <bpf/bpf_tracing.h>
0007
0008 char _license[] SEC("license") = "GPL";
0009
0010 struct {
0011     __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
0012     __uint(map_flags, BPF_F_NO_PREALLOC);
0013     __type(key, int);
0014     __type(value, long);
0015 } map_a SEC(".maps");
0016
0017 struct {
0018     __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
0019     __uint(map_flags, BPF_F_NO_PREALLOC);
0020     __type(key, int);
0021     __type(value, long);
0022 } map_b SEC(".maps");
0023
0024 SEC("fentry/bpf_local_storage_lookup")
0025 int BPF_PROG(on_lookup)
0026 {
0027     struct task_struct *task = bpf_get_current_task_btf();
0028
0029     bpf_task_storage_delete(&map_a, task);
0030     bpf_task_storage_delete(&map_b, task);
0031     return 0;
0032 }
0033
0034 SEC("fentry/bpf_local_storage_update")
0035 int BPF_PROG(on_update)
0036 {
0037     struct task_struct *task = bpf_get_current_task_btf();
0038     long *ptr;
0039
0040     ptr = bpf_task_storage_get(&map_a, task, 0,
0041                    BPF_LOCAL_STORAGE_GET_F_CREATE);
0042     if (ptr)
0043         *ptr += 1;
0044
0045     ptr = bpf_task_storage_get(&map_b, task, 0,
0046                    BPF_LOCAL_STORAGE_GET_F_CREATE);
0047     if (ptr)
0048         *ptr += 1;
0049
0050     return 0;
0051 }
0052
0053 SEC("tp_btf/sys_enter")
0054 int BPF_PROG(on_enter, struct pt_regs *regs, long id)
0055 {
0056     struct task_struct *task;
0057     long *ptr;
0058
0059     task = bpf_get_current_task_btf();
0060     ptr = bpf_task_storage_get(&map_a, task, 0,
0061                    BPF_LOCAL_STORAGE_GET_F_CREATE);
0062     if (ptr)
0063         *ptr = 200;
0064
0065     ptr = bpf_task_storage_get(&map_b, task, 0,
0066                    BPF_LOCAL_STORAGE_GET_F_CREATE);
0067     if (ptr)
0068         *ptr = 100;
0069     return 0;
0070 }