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