arch/arm64/include/asm/debug-monitors.h

   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 */