1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ 3 4 #include "vmlinux.h" 5 #include <bpf/bpf_helpers.h> 6 #include "bpf_misc.h" 7 8 struct { 9 __uint(type, BPF_MAP_TYPE_TASK_STORAGE); 10 __uint(map_flags, BPF_F_NO_PREALLOC); 11 __type(key, int); 12 __type(value, int); 13 } task_storage SEC(".maps"); 14 15 long hits; 16 long gp_hits; 17 long gp_times; 18 long current_gp_start; 19 long unexpected; 20 bool postgp_seen; 21 22 SEC("fentry/" SYS_PREFIX "sys_getpgid") get_local(void * ctx)23 int get_local(void *ctx) 24 { 25 struct task_struct *task; 26 int idx; 27 int *s; 28 29 idx = 0; 30 task = bpf_get_current_task_btf(); 31 s = bpf_task_storage_get(&task_storage, task, &idx, 32 BPF_LOCAL_STORAGE_GET_F_CREATE); 33 if (!s) 34 return 0; 35 36 *s = 3; 37 bpf_task_storage_delete(&task_storage, task); 38 __sync_add_and_fetch(&hits, 1); 39 return 0; 40 } 41 42 SEC("fentry/rcu_tasks_trace_pregp_step") pregp_step(struct pt_regs * ctx)43 int pregp_step(struct pt_regs *ctx) 44 { 45 current_gp_start = bpf_ktime_get_ns(); 46 return 0; 47 } 48 49 SEC("fentry/rcu_tasks_trace_postgp") postgp(struct pt_regs * ctx)50 int postgp(struct pt_regs *ctx) 51 { 52 if (!current_gp_start && postgp_seen) { 53 /* Will only happen if prog tracing rcu_tasks_trace_pregp_step doesn't 54 * execute before this prog 55 */ 56 __sync_add_and_fetch(&unexpected, 1); 57 return 0; 58 } 59 60 __sync_add_and_fetch(&gp_times, bpf_ktime_get_ns() - current_gp_start); 61 __sync_add_and_fetch(&gp_hits, 1); 62 current_gp_start = 0; 63 postgp_seen = true; 64 return 0; 65 } 66 67 char _license[] SEC("license") = "GPL"; 68