xref: /linux/tools/sched_ext/include/scx/user_exit_info.bpf.h (revision a23cd25baed2316e50597f8b67192bdc904f955b)
1*de68c051SAndrea Righi /* SPDX-License-Identifier: GPL-2.0 */
2*de68c051SAndrea Righi /*
3*de68c051SAndrea Righi  * Define struct user_exit_info which is shared between BPF and userspace parts
4*de68c051SAndrea Righi  * to communicate exit status and other information.
5*de68c051SAndrea Righi  *
6*de68c051SAndrea Righi  * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
7*de68c051SAndrea Righi  * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
8*de68c051SAndrea Righi  * Copyright (c) 2022 David Vernet <dvernet@meta.com>
9*de68c051SAndrea Righi  */
10*de68c051SAndrea Righi 
11*de68c051SAndrea Righi #ifndef __USER_EXIT_INFO_BPF_H
12*de68c051SAndrea Righi #define __USER_EXIT_INFO_BPF_H
13*de68c051SAndrea Righi 
14*de68c051SAndrea Righi #ifndef LSP
15*de68c051SAndrea Righi #include "vmlinux.h"
16*de68c051SAndrea Righi #endif
17*de68c051SAndrea Righi #include <bpf/bpf_core_read.h>
18*de68c051SAndrea Righi 
19*de68c051SAndrea Righi #include "user_exit_info_common.h"
20*de68c051SAndrea Righi 
21*de68c051SAndrea Righi #define UEI_DEFINE(__name)							\
22*de68c051SAndrea Righi 	char RESIZABLE_ARRAY(data, __name##_dump);				\
23*de68c051SAndrea Righi 	const volatile u32 __name##_dump_len;					\
24*de68c051SAndrea Righi 	struct user_exit_info __name SEC(".data")
25*de68c051SAndrea Righi 
26*de68c051SAndrea Righi #define UEI_RECORD(__uei_name, __ei) ({						\
27*de68c051SAndrea Righi 	bpf_probe_read_kernel_str(__uei_name.reason,				\
28*de68c051SAndrea Righi 				  sizeof(__uei_name.reason), (__ei)->reason);	\
29*de68c051SAndrea Righi 	bpf_probe_read_kernel_str(__uei_name.msg,				\
30*de68c051SAndrea Righi 				  sizeof(__uei_name.msg), (__ei)->msg);		\
31*de68c051SAndrea Righi 	bpf_probe_read_kernel_str(__uei_name##_dump,				\
32*de68c051SAndrea Righi 				  __uei_name##_dump_len, (__ei)->dump);		\
33*de68c051SAndrea Righi 	if (bpf_core_field_exists((__ei)->exit_code))				\
34*de68c051SAndrea Righi 		__uei_name.exit_code = (__ei)->exit_code;			\
35*de68c051SAndrea Righi 	/* use __sync to force memory barrier */				\
36*de68c051SAndrea Righi 	__sync_val_compare_and_swap(&__uei_name.kind, __uei_name.kind,		\
37*de68c051SAndrea Righi 				    (__ei)->kind);				\
38*de68c051SAndrea Righi })
39*de68c051SAndrea Righi 
40*de68c051SAndrea Righi #endif /* __USER_EXIT_INFO_BPF_H */
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