user_exit_info.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#ifndef __USER_EXIT_INFO_H
11#define __USER_EXIT_INFO_H
12
13#include <stdio.h>
14#include <stdbool.h>
15
16#include "user_exit_info_common.h"
17
18/* no need to call the following explicitly if SCX_OPS_LOAD() is used */
19#define UEI_SET_SIZE(__skel, __ops_name, __uei_name) ({					\
20	u32 __len = (__skel)->struct_ops.__ops_name->exit_dump_len ?: UEI_DUMP_DFL_LEN;	\
21	(__skel)->rodata->__uei_name##_dump_len = __len;				\
22	RESIZE_ARRAY((__skel), data, __uei_name##_dump, __len);				\
23})
24
25#define UEI_EXITED(__skel, __uei_name) ({					\
26	/* use __sync to force memory barrier */				\
27	__sync_val_compare_and_swap(&(__skel)->data->__uei_name.kind, -1, -1);	\
28})
29
30#define UEI_REPORT(__skel, __uei_name) ({					\
31	struct user_exit_info *__uei = &(__skel)->data->__uei_name;		\
32	char *__uei_dump = (__skel)->data_##__uei_name##_dump->__uei_name##_dump; \
33	if (__uei_dump[0] != '\0') {						\
34		fputs("\nDEBUG DUMP\n", stderr);				\
35		fputs("================================================================================\n\n", stderr); \
36		fputs(__uei_dump, stderr);					\
37		fputs("\n================================================================================\n\n", stderr); \
38	}									\
39	fprintf(stderr, "EXIT: %s", __uei->reason);				\
40	if (__uei->msg[0] != '\0')						\
41		fprintf(stderr, " (%s)", __uei->msg);				\
42	fputs("\n", stderr);							\
43	__uei->exit_code;							\
44})
45
46/*
47 * We can't import vmlinux.h while compiling user C code. Let's duplicate
48 * scx_exit_code definition.
49 */
50enum scx_exit_code {
51	/* Reasons */
52	SCX_ECODE_RSN_HOTPLUG		= 1LLU << 32,
53
54	/* Actions */
55	SCX_ECODE_ACT_RESTART		= 1LLU << 48,
56};
57
58enum uei_ecode_mask {
59	UEI_ECODE_USER_MASK		= ((1LLU << 32) - 1),
60	UEI_ECODE_SYS_RSN_MASK		= ((1LLU << 16) - 1) << 32,
61	UEI_ECODE_SYS_ACT_MASK		= ((1LLU << 16) - 1) << 48,
62};
63
64/*
65 * These macro interpret the ecode returned from UEI_REPORT().
66 */
67#define UEI_ECODE_USER(__ecode)		((__ecode) & UEI_ECODE_USER_MASK)
68#define UEI_ECODE_SYS_RSN(__ecode)	((__ecode) & UEI_ECODE_SYS_RSN_MASK)
69#define UEI_ECODE_SYS_ACT(__ecode)	((__ecode) & UEI_ECODE_SYS_ACT_MASK)
70
71#define UEI_ECODE_RESTART(__ecode)	(UEI_ECODE_SYS_ACT((__ecode)) == SCX_ECODE_ACT_RESTART)
72
73#endif	/* __USER_EXIT_INFO_H */