| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ |
| |
| #include "vmlinux.h" |
| #include <bpf/bpf_helpers.h> |
| #include "bpf_misc.h" |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_TASK_STORAGE); |
| __uint(map_flags, BPF_F_NO_PREALLOC); |
| __type(key, int); |
| __type(value, int); |
| } task_storage SEC(".maps"); |
| |
| long hits; |
| long gp_hits; |
| long gp_times; |
| long current_gp_start; |
| long unexpected; |
| bool postgp_seen; |
| |
| SEC("fentry/" SYS_PREFIX "sys_getpgid") |
| int get_local(void *ctx) |
| { |
| struct task_struct *task; |
| int idx; |
| int *s; |
| |
| idx = 0; |
| task = bpf_get_current_task_btf(); |
| s = bpf_task_storage_get(&task_storage, task, &idx, |
| BPF_LOCAL_STORAGE_GET_F_CREATE); |
| if (!s) |
| return 0; |
| |
| *s = 3; |
| bpf_task_storage_delete(&task_storage, task); |
| __sync_add_and_fetch(&hits, 1); |
| return 0; |
| } |
| |
| SEC("fentry/rcu_tasks_trace_pregp_step") |
| int pregp_step(struct pt_regs *ctx) |
| { |
| current_gp_start = bpf_ktime_get_ns(); |
| return 0; |
| } |
| |
| SEC("fentry/rcu_tasks_trace_postgp") |
| int postgp(struct pt_regs *ctx) |
| { |
| if (!current_gp_start && postgp_seen) { |
| /* Will only happen if prog tracing rcu_tasks_trace_pregp_step doesn't |
| * execute before this prog |
| */ |
| __sync_add_and_fetch(&unexpected, 1); |
| return 0; |
| } |
| |
| __sync_add_and_fetch(&gp_times, bpf_ktime_get_ns() - current_gp_start); |
| __sync_add_and_fetch(&gp_hits, 1); |
| current_gp_start = 0; |
| postgp_seen = true; |
| return 0; |
| } |
| |
| char _license[] SEC("license") = "GPL"; |