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__ 91 struct 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 98 struct step_hook { 99 struct list_head node; 100 int (*fn)(struct pt_regs *regs, unsigned int esr); 101 }; 102 103 void register_step_hook(struct step_hook *hook); 104 void unregister_step_hook(struct step_hook *hook); 105 106 struct 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 }; 112 113 void register_break_hook(struct break_hook *hook); 114 void unregister_break_hook(struct break_hook *hook); 115 116 u8 debug_monitors_arch(void); 117 118 enum dbg_active_el { 119 DBG_ACTIVE_EL0 = 0, 120 DBG_ACTIVE_EL1, 121 }; 122 123 void enable_debug_monitors(enum dbg_active_el el); 124 void disable_debug_monitors(enum dbg_active_el el); 125 126 void user_rewind_single_step(struct task_struct *task); 127 void user_fastforward_single_step(struct task_struct *task); 128 129 void kernel_enable_single_step(struct pt_regs *regs); 130 void kernel_disable_single_step(void); 131 int kernel_active_single_step(void); 132 133 #ifdef CONFIG_HAVE_HW_BREAKPOINT 134 int reinstall_suspended_bps(struct pt_regs *regs); 135 #else 136 static inline int reinstall_suspended_bps(struct pt_regs *regs) 137 { 138 return -ENODEV; 139 } 140 #endif 141 142 int aarch32_break_handler(struct pt_regs *regs); 143 144 #endif /* __ASSEMBLY */ 145 #endif /* __KERNEL__ */ 146 #endif /* __ASM_DEBUG_MONITORS_H */ 147