xref: /linux/include/linux/user_events.h (revision b83deaa741558babf4b8d51d34f6637ccfff1b26)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3  * Copyright (c) 2021, Microsoft Corporation.
4  *
5  * Authors:
6  *   Beau Belgrave <beaub@linux.microsoft.com>
7  */
8 #ifndef _UAPI_LINUX_USER_EVENTS_H
9 #define _UAPI_LINUX_USER_EVENTS_H
10 
11 #include <linux/types.h>
12 #include <linux/ioctl.h>
13 
14 #ifdef __KERNEL__
15 #include <linux/uio.h>
16 #else
17 #include <sys/uio.h>
18 #endif
19 
20 #define USER_EVENTS_SYSTEM "user_events"
21 #define USER_EVENTS_PREFIX "u:"
22 
23 /* Bits 0-6 are for known probe types, Bit 7 is for unknown probes */
24 #define EVENT_BIT_FTRACE 0
25 #define EVENT_BIT_PERF 1
26 #define EVENT_BIT_OTHER 7
27 
28 #define EVENT_STATUS_FTRACE (1 << EVENT_BIT_FTRACE)
29 #define EVENT_STATUS_PERF (1 << EVENT_BIT_PERF)
30 #define EVENT_STATUS_OTHER (1 << EVENT_BIT_OTHER)
31 
32 /* Create dynamic location entry within a 32-bit value */
33 #define DYN_LOC(offset, size) ((size) << 16 | (offset))
34 
35 /*
36  * Describes an event registration and stores the results of the registration.
37  * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum
38  * must set the size and name_args before invocation.
39  */
40 struct user_reg {
41 
42 	/* Input: Size of the user_reg structure being used */
43 	__u32 size;
44 
45 	/* Input: Pointer to string with event name, description and flags */
46 	__u64 name_args;
47 
48 	/* Output: Byte index of the event within the status page */
49 	__u32 status_index;
50 
51 	/* Output: Index of the event to use when writing data */
52 	__u32 write_index;
53 };
54 
55 #define DIAG_IOC_MAGIC '*'
56 
57 /* Requests to register a user_event */
58 #define DIAG_IOCSREG _IOWR(DIAG_IOC_MAGIC, 0, struct user_reg*)
59 
60 /* Requests to delete a user_event */
61 #define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char*)
62 
63 #endif /* _UAPI_LINUX_USER_EVENTS_H */
64