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 /* uprobes BRK opcodes with ESR encoding  */
57 #define BRK64_OPCODE_UPROBES	(AARCH64_BREAK_MON | (UPROBES_BRK_IMM << 5))
58 
59 /* AArch32 */
60 #define DBG_ESR_EVT_BKPT	0x4
61 #define DBG_ESR_EVT_VECC	0x5
62 
63 #define AARCH32_BREAK_ARM	0x07f001f0
64 #define AARCH32_BREAK_THUMB	0xde01
65 #define AARCH32_BREAK_THUMB2_LO	0xf7f0
66 #define AARCH32_BREAK_THUMB2_HI	0xa000
67 
68 #ifndef __ASSEMBLY__
69 struct task_struct;
70 
71 #define DBG_ARCH_ID_RESERVED	0	/* In case of ptrace ABI updates. */
72 
73 #define DBG_HOOK_HANDLED	0
74 #define DBG_HOOK_ERROR		1
75 
76 struct step_hook {
77 	struct list_head node;
78 	int (*fn)(struct pt_regs *regs, unsigned int esr);
79 };
80 
81 void register_user_step_hook(struct step_hook *hook);
82 void unregister_user_step_hook(struct step_hook *hook);
83 
84 void register_kernel_step_hook(struct step_hook *hook);
85 void unregister_kernel_step_hook(struct step_hook *hook);
86 
87 struct break_hook {
88 	struct list_head node;
89 	int (*fn)(struct pt_regs *regs, unsigned int esr);
90 	u16 imm;
91 	u16 mask; /* These bits are ignored when comparing with imm */
92 };
93 
94 void register_user_break_hook(struct break_hook *hook);
95 void unregister_user_break_hook(struct break_hook *hook);
96 
97 void register_kernel_break_hook(struct break_hook *hook);
98 void unregister_kernel_break_hook(struct break_hook *hook);
99 
100 u8 debug_monitors_arch(void);
101 
102 enum dbg_active_el {
103 	DBG_ACTIVE_EL0 = 0,
104 	DBG_ACTIVE_EL1,
105 };
106 
107 void enable_debug_monitors(enum dbg_active_el el);
108 void disable_debug_monitors(enum dbg_active_el el);
109 
110 void user_rewind_single_step(struct task_struct *task);
111 void user_fastforward_single_step(struct task_struct *task);
112 
113 void kernel_enable_single_step(struct pt_regs *regs);
114 void kernel_disable_single_step(void);
115 int kernel_active_single_step(void);
116 
117 #ifdef CONFIG_HAVE_HW_BREAKPOINT
118 int reinstall_suspended_bps(struct pt_regs *regs);
119 #else
reinstall_suspended_bps(struct pt_regs * regs)120 static inline int reinstall_suspended_bps(struct pt_regs *regs)
121 {
122 	return -ENODEV;
123 }
124 #endif
125 
126 int aarch32_break_handler(struct pt_regs *regs);
127 
128 #endif	/* __ASSEMBLY */
129 #endif	/* __ASM_DEBUG_MONITORS_H */
130