user_exit_info.bpf.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * Define struct user_exit_info which is shared between BPF and userspace parts
 4 * to communicate exit status and other information.
 5 *
 6 * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
 7 * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
 8 * Copyright (c) 2022 David Vernet <dvernet@meta.com>
 9 */
10
11#ifndef __USER_EXIT_INFO_BPF_H
12#define __USER_EXIT_INFO_BPF_H
13
14#ifndef LSP
15#include "vmlinux.h"
16#endif
17#include <bpf/bpf_core_read.h>
18
19#include "user_exit_info_common.h"
20
21#define UEI_DEFINE(__name)							\
22	char RESIZABLE_ARRAY(data, __name##_dump);				\
23	const volatile u32 __name##_dump_len;					\
24	struct user_exit_info __name SEC(".data")
25
26#define UEI_RECORD(__uei_name, __ei) ({						\
27	bpf_probe_read_kernel_str(__uei_name.reason,				\
28				  sizeof(__uei_name.reason), (__ei)->reason);	\
29	bpf_probe_read_kernel_str(__uei_name.msg,				\
30				  sizeof(__uei_name.msg), (__ei)->msg);		\
31	bpf_probe_read_kernel_str(__uei_name##_dump,				\
32				  __uei_name##_dump_len, (__ei)->dump);		\
33	if (bpf_core_field_exists((__ei)->exit_code))				\
34		__uei_name.exit_code = (__ei)->exit_code;			\
35	/* use __sync to force memory barrier */				\
36	__sync_val_compare_and_swap(&__uei_name.kind, __uei_name.kind,		\
37				    (__ei)->kind);				\
38})
39
40#endif /* __USER_EXIT_INFO_BPF_H */