1 // SPDX-License-Identifier: GPL-2.0 2 3 #include "vmlinux.h" 4 #include <bpf/bpf_helpers.h> 5 #include <bpf/bpf_tracing.h> 6 7 char _license[] SEC("license") = "GPL"; 8 9 #ifndef EBUSY 10 #define EBUSY 16 11 #endif 12 13 extern bool CONFIG_PREEMPT __kconfig __weak; 14 int nr_get_errs = 0; 15 int nr_del_errs = 0; 16 17 struct { 18 __uint(type, BPF_MAP_TYPE_TASK_STORAGE); 19 __uint(map_flags, BPF_F_NO_PREALLOC); 20 __type(key, int); 21 __type(value, int); 22 } task_storage SEC(".maps"); 23 24 SEC("lsm.s/socket_post_create") 25 int BPF_PROG(socket_post_create, struct socket *sock, int family, int type, 26 int protocol, int kern) 27 { 28 struct task_struct *task; 29 int ret, zero = 0; 30 int *value; 31 32 if (!CONFIG_PREEMPT) 33 return 0; 34 35 task = bpf_get_current_task_btf(); 36 value = bpf_task_storage_get(&task_storage, task, &zero, 37 BPF_LOCAL_STORAGE_GET_F_CREATE); 38 if (!value) 39 __sync_fetch_and_add(&nr_get_errs, 1); 40 41 ret = bpf_task_storage_delete(&task_storage, 42 bpf_get_current_task_btf()); 43 if (ret == -EBUSY) 44 __sync_fetch_and_add(&nr_del_errs, 1); 45 46 return 0; 47 } 48