tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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/esr.h>
24#include <asm/insn.h>
25#include <asm/ptrace.h>
26
27/* Low-level stepping controls. */
28#define DBG_MDSCR_SS (1 << 0)
29#define DBG_SPSR_SS (1 << 21)
30
31/* MDSCR_EL1 enabling bits */
32#define DBG_MDSCR_KDE (1 << 13)
33#define DBG_MDSCR_MDE (1 << 15)
34#define DBG_MDSCR_MASK ~(DBG_MDSCR_KDE | DBG_MDSCR_MDE)
35
36#define DBG_ESR_EVT(x) (((x) >> 27) & 0x7)
37
38/* AArch64 */
39#define DBG_ESR_EVT_HWBP 0x0
40#define DBG_ESR_EVT_HWSS 0x1
41#define DBG_ESR_EVT_HWWP 0x2
42#define DBG_ESR_EVT_BRK 0x6
43
44/*
45 * Break point instruction encoding
46 */
47#define BREAK_INSTR_SIZE AARCH64_INSN_SIZE
48
49/*
50 * #imm16 values used for BRK instruction generation
51 * Allowed values for kgbd are 0x400 - 0x7ff
52 * 0x100: for triggering a fault on purpose (reserved)
53 * 0x400: for dynamic BRK instruction
54 * 0x401: for compile time BRK instruction
55 * 0x800: kernel-mode BUG() and WARN() traps
56 */
57#define FAULT_BRK_IMM 0x100
58#define KGDB_DYN_DBG_BRK_IMM 0x400
59#define KGDB_COMPILED_DBG_BRK_IMM 0x401
60#define BUG_BRK_IMM 0x800
61
62/*
63 * BRK instruction encoding
64 * The #imm16 value should be placed at bits[20:5] within BRK ins
65 */
66#define AARCH64_BREAK_MON 0xd4200000
67
68/*
69 * BRK instruction for provoking a fault on purpose
70 * Unlike kgdb, #imm16 value with unallocated handler is used for faulting.
71 */
72#define AARCH64_BREAK_FAULT (AARCH64_BREAK_MON | (FAULT_BRK_IMM << 5))
73
74#define AARCH64_BREAK_KGDB_DYN_DBG \
75 (AARCH64_BREAK_MON | (KGDB_DYN_DBG_BRK_IMM << 5))
76#define KGDB_DYN_BRK_INS_BYTE(x) \
77 ((AARCH64_BREAK_KGDB_DYN_DBG >> (8 * (x))) & 0xff)
78
79#define CACHE_FLUSH_IS_SAFE 1
80
81/* AArch32 */
82#define DBG_ESR_EVT_BKPT 0x4
83#define DBG_ESR_EVT_VECC 0x5
84
85#define AARCH32_BREAK_ARM 0x07f001f0
86#define AARCH32_BREAK_THUMB 0xde01
87#define AARCH32_BREAK_THUMB2_LO 0xf7f0
88#define AARCH32_BREAK_THUMB2_HI 0xa000
89
90#ifndef __ASSEMBLY__
91struct task_struct;
92
93#define DBG_ARCH_ID_RESERVED 0 /* In case of ptrace ABI updates. */
94
95#define DBG_HOOK_HANDLED 0
96#define DBG_HOOK_ERROR 1
97
98struct step_hook {
99 struct list_head node;
100 int (*fn)(struct pt_regs *regs, unsigned int esr);
101};
102
103void register_step_hook(struct step_hook *hook);
104void unregister_step_hook(struct step_hook *hook);
105
106struct break_hook {
107 struct list_head node;
108 u32 esr_val;
109 u32 esr_mask;
110 int (*fn)(struct pt_regs *regs, unsigned int esr);
111};
112
113void register_break_hook(struct break_hook *hook);
114void unregister_break_hook(struct break_hook *hook);
115
116u8 debug_monitors_arch(void);
117
118enum dbg_active_el {
119 DBG_ACTIVE_EL0 = 0,
120 DBG_ACTIVE_EL1,
121};
122
123void enable_debug_monitors(enum dbg_active_el el);
124void disable_debug_monitors(enum dbg_active_el el);
125
126void user_rewind_single_step(struct task_struct *task);
127void user_fastforward_single_step(struct task_struct *task);
128
129void kernel_enable_single_step(struct pt_regs *regs);
130void kernel_disable_single_step(void);
131int kernel_active_single_step(void);
132
133#ifdef CONFIG_HAVE_HW_BREAKPOINT
134int reinstall_suspended_bps(struct pt_regs *regs);
135#else
136static inline int reinstall_suspended_bps(struct pt_regs *regs)
137{
138 return -ENODEV;
139}
140#endif
141
142int aarch32_break_handler(struct pt_regs *regs);
143
144#endif /* __ASSEMBLY */
145#endif /* __KERNEL__ */
146#endif /* __ASM_DEBUG_MONITORS_H */