1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_KCOV_H
3 #define _LINUX_KCOV_H
4 
5 #include <linux/sched.h>
6 #include <uapi/linux/kcov.h>
7 
8 struct task_struct;
9 
10 #ifdef CONFIG_KCOV
11 
12 enum kcov_mode {
13 	/* Coverage collection is not enabled yet. */
14 	KCOV_MODE_DISABLED = 0,
15 	/* KCOV was initialized, but tracing mode hasn't been chosen yet. */
16 	KCOV_MODE_INIT = 1,
17 	/*
18 	 * Tracing coverage collection mode.
19 	 * Covered PCs are collected in a per-task buffer.
20 	 */
21 	KCOV_MODE_TRACE_PC = 2,
22 	/* Collecting comparison operands mode. */
23 	KCOV_MODE_TRACE_CMP = 3,
24 };
25 
26 #define KCOV_IN_CTXSW	(1 << 30)
27 
28 void kcov_task_init(struct task_struct *t);
29 void kcov_task_exit(struct task_struct *t);
30 
31 #define kcov_prepare_switch(t)			\
32 do {						\
33 	(t)->kcov_mode |= KCOV_IN_CTXSW;	\
34 } while (0)
35 
36 #define kcov_finish_switch(t)			\
37 do {						\
38 	(t)->kcov_mode &= ~KCOV_IN_CTXSW;	\
39 } while (0)
40 
41 /* See Documentation/dev-tools/kcov.rst for usage details. */
42 void kcov_remote_start(u64 handle);
43 void kcov_remote_stop(void);
44 u64 kcov_common_handle(void);
45 
kcov_remote_start_common(u64 id)46 static inline void kcov_remote_start_common(u64 id)
47 {
48 	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id));
49 }
50 
kcov_remote_start_usb(u64 id)51 static inline void kcov_remote_start_usb(u64 id)
52 {
53 	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_USB, id));
54 }
55 
56 /*
57  * The softirq flavor of kcov_remote_*() functions is introduced as a temporary
58  * work around for kcov's lack of nested remote coverage sections support in
59  * task context. Adding suport for nested sections is tracked in:
60  * https://bugzilla.kernel.org/show_bug.cgi?id=210337
61  */
62 
kcov_remote_start_usb_softirq(u64 id)63 static inline void kcov_remote_start_usb_softirq(u64 id)
64 {
65 	if (in_serving_softirq())
66 		kcov_remote_start_usb(id);
67 }
68 
kcov_remote_stop_softirq(void)69 static inline void kcov_remote_stop_softirq(void)
70 {
71 	if (in_serving_softirq())
72 		kcov_remote_stop();
73 }
74 
75 #else
76 
kcov_task_init(struct task_struct * t)77 static inline void kcov_task_init(struct task_struct *t) {}
kcov_task_exit(struct task_struct * t)78 static inline void kcov_task_exit(struct task_struct *t) {}
kcov_prepare_switch(struct task_struct * t)79 static inline void kcov_prepare_switch(struct task_struct *t) {}
kcov_finish_switch(struct task_struct * t)80 static inline void kcov_finish_switch(struct task_struct *t) {}
kcov_remote_start(u64 handle)81 static inline void kcov_remote_start(u64 handle) {}
kcov_remote_stop(void)82 static inline void kcov_remote_stop(void) {}
kcov_common_handle(void)83 static inline u64 kcov_common_handle(void)
84 {
85 	return 0;
86 }
kcov_remote_start_common(u64 id)87 static inline void kcov_remote_start_common(u64 id) {}
kcov_remote_start_usb(u64 id)88 static inline void kcov_remote_start_usb(u64 id) {}
kcov_remote_start_usb_softirq(u64 id)89 static inline void kcov_remote_start_usb_softirq(u64 id) {}
kcov_remote_stop_softirq(void)90 static inline void kcov_remote_stop_softirq(void) {}
91 
92 #endif /* CONFIG_KCOV */
93 #endif /* _LINUX_KCOV_H */
94