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1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  */
5 #ifndef __ASM_DEBUG_MONITORS_H
6 #define __ASM_DEBUG_MONITORS_H
7 
8 #include <linux/errno.h>
9 #include <linux/types.h>
10 #include <asm/brk-imm.h>
11 #include <asm/esr.h>
12 #include <asm/insn.h>
13 #include <asm/ptrace.h>
14 
15 /* Low-level stepping controls. */
16 #define DBG_MDSCR_SS		(1 << 0)
17 #define DBG_SPSR_SS		(1 << 21)
18 
19 /* MDSCR_EL1 enabling bits */
20 #define DBG_MDSCR_KDE		(1 << 13)
21 #define DBG_MDSCR_MDE		(1 << 15)
22 #define DBG_MDSCR_MASK		~(DBG_MDSCR_KDE | DBG_MDSCR_MDE)
23 
24 #define	DBG_ESR_EVT(x)		(((x) >> 27) & 0x7)
25 
26 /* AArch64 */
27 #define DBG_ESR_EVT_HWBP	0x0
28 #define DBG_ESR_EVT_HWSS	0x1
29 #define DBG_ESR_EVT_HWWP	0x2
30 #define DBG_ESR_EVT_BRK		0x6
31 
32 /*
33  * Break point instruction encoding
34  */
35 #define BREAK_INSTR_SIZE		AARCH64_INSN_SIZE
36 
37 /*
38  * BRK instruction encoding
39  * The #imm16 value should be placed at bits[20:5] within BRK ins
40  */
41 #define AARCH64_BREAK_MON	0xd4200000
42 
43 /*
44  * BRK instruction for provoking a fault on purpose
45  * Unlike kgdb, #imm16 value with unallocated handler is used for faulting.
46  */
47 #define AARCH64_BREAK_FAULT	(AARCH64_BREAK_MON | (FAULT_BRK_IMM << 5))
48 
49 #define AARCH64_BREAK_KGDB_DYN_DBG	\
50 	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
51 
52 #define CACHE_FLUSH_IS_SAFE		1
53 
54 /* kprobes BRK opcodes with ESR encoding  */
55 #define BRK64_OPCODE_KPROBES	(AARCH64_BREAK_MON | (KPROBES_BRK_IMM << 5))
56 #define BRK64_OPCODE_KPROBES_SS	(AARCH64_BREAK_MON | (KPROBES_BRK_SS_IMM << 5))
57 /* uprobes BRK opcodes with ESR encoding  */
58 #define BRK64_OPCODE_UPROBES	(AARCH64_BREAK_MON | (UPROBES_BRK_IMM << 5))
59 
60 /* AArch32 */
61 #define DBG_ESR_EVT_BKPT	0x4
62 #define DBG_ESR_EVT_VECC	0x5
63 
64 #define AARCH32_BREAK_ARM	0x07f001f0
65 #define AARCH32_BREAK_THUMB	0xde01
66 #define AARCH32_BREAK_THUMB2_LO	0xf7f0
67 #define AARCH32_BREAK_THUMB2_HI	0xa000
68 
69 #ifndef __ASSEMBLY__
70 struct task_struct;
71 
72 #define DBG_ARCH_ID_RESERVED	0	/* In case of ptrace ABI updates. */
73 
74 #define DBG_HOOK_HANDLED	0
75 #define DBG_HOOK_ERROR		1
76 
77 struct step_hook {
78 	struct list_head node;
79 	int (*fn)(struct pt_regs *regs, unsigned int esr);
80 };
81 
82 void register_user_step_hook(struct step_hook *hook);
83 void unregister_user_step_hook(struct step_hook *hook);
84 
85 void register_kernel_step_hook(struct step_hook *hook);
86 void unregister_kernel_step_hook(struct step_hook *hook);
87 
88 struct break_hook {
89 	struct list_head node;
90 	int (*fn)(struct pt_regs *regs, unsigned int esr);
91 	u16 imm;
92 	u16 mask; /* These bits are ignored when comparing with imm */
93 };
94 
95 void register_user_break_hook(struct break_hook *hook);
96 void unregister_user_break_hook(struct break_hook *hook);
97 
98 void register_kernel_break_hook(struct break_hook *hook);
99 void unregister_kernel_break_hook(struct break_hook *hook);
100 
101 u8 debug_monitors_arch(void);
102 
103 enum dbg_active_el {
104 	DBG_ACTIVE_EL0 = 0,
105 	DBG_ACTIVE_EL1,
106 };
107 
108 void enable_debug_monitors(enum dbg_active_el el);
109 void disable_debug_monitors(enum dbg_active_el el);
110 
111 void user_rewind_single_step(struct task_struct *task);
112 void user_fastforward_single_step(struct task_struct *task);
113 void user_regs_reset_single_step(struct user_pt_regs *regs,
114 				 struct task_struct *task);
115 
116 void kernel_enable_single_step(struct pt_regs *regs);
117 void kernel_disable_single_step(void);
118 int kernel_active_single_step(void);
119 void kernel_rewind_single_step(struct pt_regs *regs);
120 
121 #ifdef CONFIG_HAVE_HW_BREAKPOINT
122 int reinstall_suspended_bps(struct pt_regs *regs);
123 #else
reinstall_suspended_bps(struct pt_regs * regs)124 static inline int reinstall_suspended_bps(struct pt_regs *regs)
125 {
126 	return -ENODEV;
127 }
128 #endif
129 
130 int aarch32_break_handler(struct pt_regs *regs);
131 
132 #endif	/* __ASSEMBLY */
133 #endif	/* __ASM_DEBUG_MONITORS_H */
134