diff options
Diffstat (limited to 'include/linux/kcov.h')
| -rw-r--r-- | include/linux/kcov.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/include/linux/kcov.h b/include/linux/kcov.h index a10e84707d82..75a2fb8b16c3 100644 --- a/include/linux/kcov.h +++ b/include/linux/kcov.h @@ -2,6 +2,7 @@ #ifndef _LINUX_KCOV_H #define _LINUX_KCOV_H +#include <linux/sched.h> #include <uapi/linux/kcov.h> struct task_struct; @@ -20,6 +21,8 @@ enum kcov_mode { 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) @@ -52,6 +55,68 @@ 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) {} @@ -66,6 +131,11 @@ static inline u64 kcov_common_handle(void) } 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 */ |