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1 /*
2  * Copyright (C) 2012 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef __ASM_DEBUG_MONITORS_H
17 #define __ASM_DEBUG_MONITORS_H
18 
19 #ifdef __KERNEL__
20 
21 #include <linux/errno.h>
22 #include <linux/types.h>
23 #include <asm/brk-imm.h>
24 #include <asm/esr.h>
25 #include <asm/insn.h>
26 #include <asm/ptrace.h>
27 
28 /* Low-level stepping controls. */
29 #define DBG_MDSCR_SS		(1 << 0)
30 #define DBG_SPSR_SS		(1 << 21)
31 
32 /* MDSCR_EL1 enabling bits */
33 #define DBG_MDSCR_KDE		(1 << 13)
34 #define DBG_MDSCR_MDE		(1 << 15)
35 #define DBG_MDSCR_MASK		~(DBG_MDSCR_KDE | DBG_MDSCR_MDE)
36 
37 #define	DBG_ESR_EVT(x)		(((x) >> 27) & 0x7)
38 
39 /* AArch64 */
40 #define DBG_ESR_EVT_HWBP	0x0
41 #define DBG_ESR_EVT_HWSS	0x1
42 #define DBG_ESR_EVT_HWWP	0x2
43 #define DBG_ESR_EVT_BRK		0x6
44 
45 /*
46  * Break point instruction encoding
47  */
48 #define BREAK_INSTR_SIZE		AARCH64_INSN_SIZE
49 
50 /*
51  * BRK instruction encoding
52  * The #imm16 value should be placed at bits[20:5] within BRK ins
53  */
54 #define AARCH64_BREAK_MON	0xd4200000
55 
56 /*
57  * BRK instruction for provoking a fault on purpose
58  * Unlike kgdb, #imm16 value with unallocated handler is used for faulting.
59  */
60 #define AARCH64_BREAK_FAULT	(AARCH64_BREAK_MON | (FAULT_BRK_IMM << 5))
61 
62 #define AARCH64_BREAK_KGDB_DYN_DBG	\
63 	(AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
64 #define KGDB_DYN_BRK_INS_BYTE(x)	\
65 	((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
66 
67 #define CACHE_FLUSH_IS_SAFE		1
68 
69 /* AArch32 */
70 #define DBG_ESR_EVT_BKPT	0x4
71 #define DBG_ESR_EVT_VECC	0x5
72 
73 #define AARCH32_BREAK_ARM	0x07f001f0
74 #define AARCH32_BREAK_THUMB	0xde01
75 #define AARCH32_BREAK_THUMB2_LO	0xf7f0
76 #define AARCH32_BREAK_THUMB2_HI	0xa000
77 
78 #ifndef __ASSEMBLY__
79 struct task_struct;
80 
81 #define DBG_ARCH_ID_RESERVED	0	/* In case of ptrace ABI updates. */
82 
83 #define DBG_HOOK_HANDLED	0
84 #define DBG_HOOK_ERROR		1
85 
86 struct step_hook {
87 	struct list_head node;
88 	int (*fn)(struct pt_regs *regs, unsigned int esr);
89 };
90 
91 void register_step_hook(struct step_hook *hook);
92 void unregister_step_hook(struct step_hook *hook);
93 
94 struct break_hook {
95 	struct list_head node;
96 	u32 esr_val;
97 	u32 esr_mask;
98 	int (*fn)(struct pt_regs *regs, unsigned int esr);
99 };
100 
101 void register_break_hook(struct break_hook *hook);
102 void unregister_break_hook(struct break_hook *hook);
103 
104 u8 debug_monitors_arch(void);
105 
106 enum dbg_active_el {
107 	DBG_ACTIVE_EL0 = 0,
108 	DBG_ACTIVE_EL1,
109 };
110 
111 void enable_debug_monitors(enum dbg_active_el el);
112 void disable_debug_monitors(enum dbg_active_el el);
113 
114 void user_rewind_single_step(struct task_struct *task);
115 void user_fastforward_single_step(struct task_struct *task);
116 
117 void kernel_enable_single_step(struct pt_regs *regs);
118 void kernel_disable_single_step(void);
119 int kernel_active_single_step(void);
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	/* __KERNEL__ */
134 #endif	/* __ASM_DEBUG_MONITORS_H */
135