xref: /openbmc/linux/include/linux/kcov.h (revision 0edabdfe89581669609eaac5f6a8d0ae6fe95e7f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_KCOV_H
3 #define _LINUX_KCOV_H
4 
5 #include <uapi/linux/kcov.h>
6 
7 struct task_struct;
8 
9 #ifdef CONFIG_KCOV
10 
11 enum kcov_mode {
12 	/* Coverage collection is not enabled yet. */
13 	KCOV_MODE_DISABLED = 0,
14 	/* KCOV was initialized, but tracing mode hasn't been chosen yet. */
15 	KCOV_MODE_INIT = 1,
16 	/*
17 	 * Tracing coverage collection mode.
18 	 * Covered PCs are collected in a per-task buffer.
19 	 */
20 	KCOV_MODE_TRACE_PC = 2,
21 	/* Collecting comparison operands mode. */
22 	KCOV_MODE_TRACE_CMP = 3,
23 };
24 
25 #define KCOV_IN_CTXSW	(1 << 30)
26 
27 void kcov_task_init(struct task_struct *t);
28 void kcov_task_exit(struct task_struct *t);
29 
30 #define kcov_prepare_switch(t)			\
31 do {						\
32 	(t)->kcov_mode |= KCOV_IN_CTXSW;	\
33 } while (0)
34 
35 #define kcov_finish_switch(t)			\
36 do {						\
37 	(t)->kcov_mode &= ~KCOV_IN_CTXSW;	\
38 } while (0)
39 
40 /* See Documentation/dev-tools/kcov.rst for usage details. */
41 void kcov_remote_start(u64 handle);
42 void kcov_remote_stop(void);
43 u64 kcov_common_handle(void);
44 
45 static inline void kcov_remote_start_common(u64 id)
46 {
47 	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id));
48 }
49 
50 static inline void kcov_remote_start_usb(u64 id)
51 {
52 	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_USB, id));
53 }
54 
55 /*
56  * The softirq flavor of kcov_remote_*() functions is introduced as a temporary
57  * work around for kcov's lack of nested remote coverage sections support in
58  * task context. Adding suport for nested sections is tracked in:
59  * https://bugzilla.kernel.org/show_bug.cgi?id=210337
60  */
61 
62 static inline void kcov_remote_start_usb_softirq(u64 id)
63 {
64 	if (in_serving_softirq())
65 		kcov_remote_start_usb(id);
66 }
67 
68 static inline void kcov_remote_stop_softirq(void)
69 {
70 	if (in_serving_softirq())
71 		kcov_remote_stop();
72 }
73 
74 #else
75 
76 static inline void kcov_task_init(struct task_struct *t) {}
77 static inline void kcov_task_exit(struct task_struct *t) {}
78 static inline void kcov_prepare_switch(struct task_struct *t) {}
79 static inline void kcov_finish_switch(struct task_struct *t) {}
80 static inline void kcov_remote_start(u64 handle) {}
81 static inline void kcov_remote_stop(void) {}
82 static inline u64 kcov_common_handle(void)
83 {
84 	return 0;
85 }
86 static inline void kcov_remote_start_common(u64 id) {}
87 static inline void kcov_remote_start_usb(u64 id) {}
88 static inline void kcov_remote_start_usb_softirq(u64 id) {}
89 static inline void kcov_remote_stop_softirq(void) {}
90 
91 #endif /* CONFIG_KCOV */
92 #endif /* _LINUX_KCOV_H */
93