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 /* Low-level stepping controls. */ 22 #define DBG_MDSCR_SS (1 << 0) 23 #define DBG_SPSR_SS (1 << 21) 24 25 /* MDSCR_EL1 enabling bits */ 26 #define DBG_MDSCR_KDE (1 << 13) 27 #define DBG_MDSCR_MDE (1 << 15) 28 #define DBG_MDSCR_MASK ~(DBG_MDSCR_KDE | DBG_MDSCR_MDE) 29 30 #define DBG_ESR_EVT(x) (((x) >> 27) & 0x7) 31 32 /* AArch64 */ 33 #define DBG_ESR_EVT_HWBP 0x0 34 #define DBG_ESR_EVT_HWSS 0x1 35 #define DBG_ESR_EVT_HWWP 0x2 36 #define DBG_ESR_EVT_BRK 0x6 37 38 /* 39 * Break point instruction encoding 40 */ 41 #define BREAK_INSTR_SIZE 4 42 43 /* 44 * ESR values expected for dynamic and compile time BRK instruction 45 */ 46 #define DBG_ESR_VAL_BRK(x) (0xf2000000 | ((x) & 0xfffff)) 47 48 /* 49 * #imm16 values used for BRK instruction generation 50 * Allowed values for kgbd are 0x400 - 0x7ff 51 * 0x100: for triggering a fault on purpose (reserved) 52 * 0x400: for dynamic BRK instruction 53 * 0x401: for compile time BRK instruction 54 */ 55 #define FAULT_BRK_IMM 0x100 56 #define KGDB_DYN_DBG_BRK_IMM 0x400 57 #define KGDB_COMPILED_DBG_BRK_IMM 0x401 58 59 /* 60 * BRK instruction encoding 61 * The #imm16 value should be placed at bits[20:5] within BRK ins 62 */ 63 #define AARCH64_BREAK_MON 0xd4200000 64 65 /* 66 * BRK instruction for provoking a fault on purpose 67 * Unlike kgdb, #imm16 value with unallocated handler is used for faulting. 68 */ 69 #define AARCH64_BREAK_FAULT (AARCH64_BREAK_MON | (FAULT_BRK_IMM << 5)) 70 71 /* 72 * Extract byte from BRK instruction 73 */ 74 #define KGDB_DYN_DBG_BRK_INS_BYTE(x) \ 75 ((((AARCH64_BREAK_MON) & 0xffe0001f) >> (x * 8)) & 0xff) 76 77 /* 78 * Extract byte from BRK #imm16 79 */ 80 #define KGBD_DYN_DBG_BRK_IMM_BYTE(x) \ 81 (((((KGDB_DYN_DBG_BRK_IMM) & 0xffff) << 5) >> (x * 8)) & 0xff) 82 83 #define KGDB_DYN_DBG_BRK_BYTE(x) \ 84 (KGDB_DYN_DBG_BRK_INS_BYTE(x) | KGBD_DYN_DBG_BRK_IMM_BYTE(x)) 85 86 #define KGDB_DYN_BRK_INS_BYTE0 KGDB_DYN_DBG_BRK_BYTE(0) 87 #define KGDB_DYN_BRK_INS_BYTE1 KGDB_DYN_DBG_BRK_BYTE(1) 88 #define KGDB_DYN_BRK_INS_BYTE2 KGDB_DYN_DBG_BRK_BYTE(2) 89 #define KGDB_DYN_BRK_INS_BYTE3 KGDB_DYN_DBG_BRK_BYTE(3) 90 91 #define CACHE_FLUSH_IS_SAFE 1 92 93 /* AArch32 */ 94 #define DBG_ESR_EVT_BKPT 0x4 95 #define DBG_ESR_EVT_VECC 0x5 96 97 #define AARCH32_BREAK_ARM 0x07f001f0 98 #define AARCH32_BREAK_THUMB 0xde01 99 #define AARCH32_BREAK_THUMB2_LO 0xf7f0 100 #define AARCH32_BREAK_THUMB2_HI 0xa000 101 102 #ifndef __ASSEMBLY__ 103 struct task_struct; 104 105 #define DBG_ARCH_ID_RESERVED 0 /* In case of ptrace ABI updates. */ 106 107 #define DBG_HOOK_HANDLED 0 108 #define DBG_HOOK_ERROR 1 109 110 struct step_hook { 111 struct list_head node; 112 int (*fn)(struct pt_regs *regs, unsigned int esr); 113 }; 114 115 void register_step_hook(struct step_hook *hook); 116 void unregister_step_hook(struct step_hook *hook); 117 118 struct break_hook { 119 struct list_head node; 120 u32 esr_val; 121 u32 esr_mask; 122 int (*fn)(struct pt_regs *regs, unsigned int esr); 123 }; 124 125 void register_break_hook(struct break_hook *hook); 126 void unregister_break_hook(struct break_hook *hook); 127 128 u8 debug_monitors_arch(void); 129 130 enum debug_el { 131 DBG_ACTIVE_EL0 = 0, 132 DBG_ACTIVE_EL1, 133 }; 134 135 void enable_debug_monitors(enum debug_el el); 136 void disable_debug_monitors(enum debug_el el); 137 138 void user_rewind_single_step(struct task_struct *task); 139 void user_fastforward_single_step(struct task_struct *task); 140 141 void kernel_enable_single_step(struct pt_regs *regs); 142 void kernel_disable_single_step(void); 143 int kernel_active_single_step(void); 144 145 #ifdef CONFIG_HAVE_HW_BREAKPOINT 146 int reinstall_suspended_bps(struct pt_regs *regs); 147 #else 148 static inline int reinstall_suspended_bps(struct pt_regs *regs) 149 { 150 return -ENODEV; 151 } 152 #endif 153 154 int aarch32_break_handler(struct pt_regs *regs); 155 156 #endif /* __ASSEMBLY */ 157 #endif /* __KERNEL__ */ 158 #endif /* __ASM_DEBUG_MONITORS_H */ 159