142 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			142 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef _LINUX_KCOV_H
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| #define _LINUX_KCOV_H
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| 
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| #include <linux/sched.h>
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| #include <uapi/linux/kcov.h>
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| 
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| struct task_struct;
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| 
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| #ifdef CONFIG_KCOV
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| 
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| enum kcov_mode {
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| 	/* Coverage collection is not enabled yet. */
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| 	KCOV_MODE_DISABLED = 0,
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| 	/* KCOV was initialized, but tracing mode hasn't been chosen yet. */
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| 	KCOV_MODE_INIT = 1,
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| 	/*
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| 	 * Tracing coverage collection mode.
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| 	 * Covered PCs are collected in a per-task buffer.
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| 	 */
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| 	KCOV_MODE_TRACE_PC = 2,
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| 	/* Collecting comparison operands mode. */
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| 	KCOV_MODE_TRACE_CMP = 3,
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| 	/* The process owns a KCOV remote reference. */
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| 	KCOV_MODE_REMOTE = 4,
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| };
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| 
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| #define KCOV_IN_CTXSW	(1 << 30)
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| 
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| void kcov_task_init(struct task_struct *t);
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| void kcov_task_exit(struct task_struct *t);
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| 
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| #define kcov_prepare_switch(t)			\
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| do {						\
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| 	(t)->kcov_mode |= KCOV_IN_CTXSW;	\
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| } while (0)
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| 
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| #define kcov_finish_switch(t)			\
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| do {						\
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| 	(t)->kcov_mode &= ~KCOV_IN_CTXSW;	\
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| } while (0)
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| 
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| /* See Documentation/dev-tools/kcov.rst for usage details. */
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| void kcov_remote_start(u64 handle);
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| void kcov_remote_stop(void);
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| u64 kcov_common_handle(void);
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| 
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| static inline void kcov_remote_start_common(u64 id)
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| {
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| 	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id));
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| }
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| 
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| static inline void kcov_remote_start_usb(u64 id)
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| {
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| 	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_USB, id));
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| }
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| 
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| /*
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|  * The softirq flavor of kcov_remote_*() functions is introduced as a temporary
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|  * workaround for KCOV's lack of nested remote coverage sections support.
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|  *
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|  * Adding support is tracked in https://bugzilla.kernel.org/show_bug.cgi?id=210337.
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|  *
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|  * kcov_remote_start_usb_softirq():
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|  *
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|  * 1. Only collects coverage when called in the softirq context. This allows
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|  *    avoiding nested remote coverage collection sections in the task context.
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|  *    For example, USB/IP calls usb_hcd_giveback_urb() in the task context
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|  *    within an existing remote coverage collection section. Thus, KCOV should
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|  *    not attempt to start collecting coverage within the coverage collection
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|  *    section in __usb_hcd_giveback_urb() in this case.
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|  *
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|  * 2. Disables interrupts for the duration of the coverage collection section.
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|  *    This allows avoiding nested remote coverage collection sections in the
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|  *    softirq context (a softirq might occur during the execution of a work in
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|  *    the BH workqueue, which runs with in_serving_softirq() > 0).
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|  *    For example, usb_giveback_urb_bh() runs in the BH workqueue with
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|  *    interrupts enabled, so __usb_hcd_giveback_urb() might be interrupted in
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|  *    the middle of its remote coverage collection section, and the interrupt
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|  *    handler might invoke __usb_hcd_giveback_urb() again.
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|  */
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| 
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| static inline unsigned long kcov_remote_start_usb_softirq(u64 id)
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| {
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| 	unsigned long flags = 0;
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| 
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| 	if (in_serving_softirq()) {
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| 		local_irq_save(flags);
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| 		kcov_remote_start_usb(id);
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| 	}
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| 
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| 	return flags;
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| }
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| 
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| static inline void kcov_remote_stop_softirq(unsigned long flags)
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| {
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| 	if (in_serving_softirq()) {
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| 		kcov_remote_stop();
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| 		local_irq_restore(flags);
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| 	}
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| }
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| 
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| #ifdef CONFIG_64BIT
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| typedef unsigned long kcov_u64;
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| #else
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| typedef unsigned long long kcov_u64;
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| #endif
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| 
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| void __sanitizer_cov_trace_pc(void);
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| void __sanitizer_cov_trace_cmp1(u8 arg1, u8 arg2);
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| void __sanitizer_cov_trace_cmp2(u16 arg1, u16 arg2);
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| void __sanitizer_cov_trace_cmp4(u32 arg1, u32 arg2);
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| void __sanitizer_cov_trace_cmp8(kcov_u64 arg1, kcov_u64 arg2);
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| void __sanitizer_cov_trace_const_cmp1(u8 arg1, u8 arg2);
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| void __sanitizer_cov_trace_const_cmp2(u16 arg1, u16 arg2);
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| void __sanitizer_cov_trace_const_cmp4(u32 arg1, u32 arg2);
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| void __sanitizer_cov_trace_const_cmp8(kcov_u64 arg1, kcov_u64 arg2);
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| void __sanitizer_cov_trace_switch(kcov_u64 val, void *cases);
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| 
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| #else
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| 
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| static inline void kcov_task_init(struct task_struct *t) {}
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| static inline void kcov_task_exit(struct task_struct *t) {}
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| static inline void kcov_prepare_switch(struct task_struct *t) {}
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| static inline void kcov_finish_switch(struct task_struct *t) {}
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| static inline void kcov_remote_start(u64 handle) {}
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| static inline void kcov_remote_stop(void) {}
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| static inline u64 kcov_common_handle(void)
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| {
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| 	return 0;
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| }
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| static inline void kcov_remote_start_common(u64 id) {}
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| static inline void kcov_remote_start_usb(u64 id) {}
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| static inline unsigned long kcov_remote_start_usb_softirq(u64 id)
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| {
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| 	return 0;
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| }
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| static inline void kcov_remote_stop_softirq(unsigned long flags) {}
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| 
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| #endif /* CONFIG_KCOV */
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| #endif /* _LINUX_KCOV_H */
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