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