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// SPDX-License-Identifier: GPL-2.0
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
char _license[] SEC("license") = "GPL";
#ifndef EBUSY
#define EBUSY 16
#endif
extern bool CONFIG_PREEMPTION __kconfig __weak;
int nr_get_errs = 0;
int nr_del_errs = 0;
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");
SEC("lsm.s/socket_post_create")
int BPF_PROG(socket_post_create, struct socket *sock, int family, int type,
int protocol, int kern)
{
struct task_struct *task;
int ret, zero = 0;
int *value;
if (!CONFIG_PREEMPTION)
return 0;
task = bpf_get_current_task_btf();
value = bpf_task_storage_get(&task_storage, task, &zero,
BPF_LOCAL_STORAGE_GET_F_CREATE);
if (!value)
__sync_fetch_and_add(&nr_get_errs, 1);
ret = bpf_task_storage_delete(&task_storage,
bpf_get_current_task_btf());
if (ret == -EBUSY)
__sync_fetch_and_add(&nr_del_errs, 1);
return 0;
}
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