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		864232fa1a
		
	
	
	
	
		
			
			For debuggers to take advantage of the hw-breakpoint framework in the kernel, it is necessary to expose the API calls via a ptrace interface. This patch exposes the hardware breakpoints framework as a collection of virtual registers, accesible using PTRACE_SETHBPREGS and PTRACE_GETHBPREGS requests. The breakpoints are stored in the debug_info struct of the running thread. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: S. Karthikeyan <informkarthik@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
		
			
				
	
	
		
			134 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			134 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _ARM_HW_BREAKPOINT_H
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| #define _ARM_HW_BREAKPOINT_H
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| 
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| #ifdef __KERNEL__
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| 
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| struct task_struct;
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| 
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| #ifdef CONFIG_HAVE_HW_BREAKPOINT
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| 
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| struct arch_hw_breakpoint_ctrl {
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| 		u32 __reserved	: 9,
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| 		mismatch	: 1,
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| 				: 9,
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| 		len		: 8,
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| 		type		: 2,
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| 		privilege	: 2,
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| 		enabled		: 1;
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| };
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| 
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| struct arch_hw_breakpoint {
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| 	u32	address;
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| 	u32	trigger;
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| 	struct perf_event *suspended_wp;
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| 	struct arch_hw_breakpoint_ctrl ctrl;
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| };
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| 
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| static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
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| {
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| 	return (ctrl.mismatch << 22) | (ctrl.len << 5) | (ctrl.type << 3) |
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| 		(ctrl.privilege << 1) | ctrl.enabled;
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| }
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| 
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| static inline void decode_ctrl_reg(u32 reg,
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| 				   struct arch_hw_breakpoint_ctrl *ctrl)
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| {
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| 	ctrl->enabled	= reg & 0x1;
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| 	reg >>= 1;
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| 	ctrl->privilege	= reg & 0x3;
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| 	reg >>= 2;
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| 	ctrl->type	= reg & 0x3;
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| 	reg >>= 2;
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| 	ctrl->len	= reg & 0xff;
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| 	reg >>= 17;
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| 	ctrl->mismatch	= reg & 0x1;
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| }
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| 
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| /* Debug architecture numbers. */
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| #define ARM_DEBUG_ARCH_RESERVED	0	/* In case of ptrace ABI updates. */
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| #define ARM_DEBUG_ARCH_V6	1
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| #define ARM_DEBUG_ARCH_V6_1	2
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| #define ARM_DEBUG_ARCH_V7_ECP14	3
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| #define ARM_DEBUG_ARCH_V7_MM	4
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| 
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| /* Breakpoint */
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| #define ARM_BREAKPOINT_EXECUTE	0
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| 
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| /* Watchpoints */
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| #define ARM_BREAKPOINT_LOAD	1
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| #define ARM_BREAKPOINT_STORE	2
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| 
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| /* Privilege Levels */
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| #define ARM_BREAKPOINT_PRIV	1
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| #define ARM_BREAKPOINT_USER	2
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| 
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| /* Lengths */
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| #define ARM_BREAKPOINT_LEN_1	0x1
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| #define ARM_BREAKPOINT_LEN_2	0x3
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| #define ARM_BREAKPOINT_LEN_4	0xf
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| #define ARM_BREAKPOINT_LEN_8	0xff
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| 
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| /* Limits */
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| #define ARM_MAX_BRP		16
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| #define ARM_MAX_WRP		16
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| #define ARM_MAX_HBP_SLOTS	(ARM_MAX_BRP + ARM_MAX_WRP)
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| 
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| /* DSCR method of entry bits. */
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| #define ARM_DSCR_MOE(x)			((x >> 2) & 0xf)
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| #define ARM_ENTRY_BREAKPOINT		0x1
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| #define ARM_ENTRY_ASYNC_WATCHPOINT	0x2
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| #define ARM_ENTRY_SYNC_WATCHPOINT	0xa
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| 
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| /* DSCR monitor/halting bits. */
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| #define ARM_DSCR_HDBGEN		(1 << 14)
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| #define ARM_DSCR_MDBGEN		(1 << 15)
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| 
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| /* opcode2 numbers for the co-processor instructions. */
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| #define ARM_OP2_BVR		4
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| #define ARM_OP2_BCR		5
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| #define ARM_OP2_WVR		6
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| #define ARM_OP2_WCR		7
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| 
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| /* Base register numbers for the debug registers. */
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| #define ARM_BASE_BVR		64
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| #define ARM_BASE_BCR		80
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| #define ARM_BASE_WVR		96
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| #define ARM_BASE_WCR		112
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| 
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| /* Accessor macros for the debug registers. */
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| #define ARM_DBG_READ(M, OP2, VAL) do {\
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| 	asm volatile("mrc p14, 0, %0, c0," #M ", " #OP2 : "=r" (VAL));\
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| } while (0)
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| 
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| #define ARM_DBG_WRITE(M, OP2, VAL) do {\
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| 	asm volatile("mcr p14, 0, %0, c0," #M ", " #OP2 : : "r" (VAL));\
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| } while (0)
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| 
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| struct notifier_block;
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| struct perf_event;
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| struct pmu;
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| 
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| extern struct pmu perf_ops_bp;
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| extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
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| 				  int *gen_len, int *gen_type);
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| extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
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| extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
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| extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
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| 					   unsigned long val, void *data);
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| 
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| extern u8 arch_get_debug_arch(void);
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| extern u8 arch_get_max_wp_len(void);
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| extern void clear_ptrace_hw_breakpoint(struct task_struct *tsk);
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| 
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| int arch_install_hw_breakpoint(struct perf_event *bp);
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| void arch_uninstall_hw_breakpoint(struct perf_event *bp);
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| void hw_breakpoint_pmu_read(struct perf_event *bp);
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| int hw_breakpoint_slots(int type);
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| 
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| #else
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| static inline void clear_ptrace_hw_breakpoint(struct task_struct *tsk) {}
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| 
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| #endif	/* CONFIG_HAVE_HW_BREAKPOINT */
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| #endif	/* __KERNEL__ */
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| #endif	/* _ARM_HW_BREAKPOINT_H */
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