arch/x86/include/asm/kprobes.h

   1 #ifndef _ASM_X86_KPROBES_H
   2 #define _ASM_X86_KPROBES_H
   3 /*
   4  *  Kernel Probes (KProbes)
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  *
  20  * Copyright (C) IBM Corporation, 2002, 2004
  21  *
  22  * See arch/x86/kernel/kprobes.c for x86 kprobes history.
  23  */
  24
  25 #include <asm-generic/kprobes.h>
  26
  27 #define BREAKPOINT_INSTRUCTION  0xcc
  28
  29 #ifdef CONFIG_KPROBES
  30 #include <linux/types.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/percpu.h>
  33 #include <asm/insn.h>
  34
  35 #define  __ARCH_WANT_KPROBES_INSN_SLOT
  36
  37 struct pt_regs;
  38 struct kprobe;
  39
  40 typedef u8 kprobe_opcode_t;
  41 #define RELATIVEJUMP_OPCODE 0xe9
  42 #define RELATIVEJUMP_SIZE 5
  43 #define RELATIVECALL_OPCODE 0xe8
  44 #define RELATIVE_ADDR_SIZE 4
  45 #define MAX_STACK_SIZE 64
  46 #define CUR_STACK_SIZE(ADDR) \
  47         (current_top_of_stack() - (unsigned long)(ADDR))
  48 #define MIN_STACK_SIZE(ADDR)                            \
  49         (MAX_STACK_SIZE < CUR_STACK_SIZE(ADDR) ?        \
  50          MAX_STACK_SIZE : CUR_STACK_SIZE(ADDR))
  51
  52 #define flush_insn_slot(p)      do { } while (0)
  53
  54 /* optinsn template addresses */
  55 extern __visible kprobe_opcode_t optprobe_template_entry;
  56 extern __visible kprobe_opcode_t optprobe_template_val;
  57 extern __visible kprobe_opcode_t optprobe_template_call;
  58 extern __visible kprobe_opcode_t optprobe_template_end;
  59 #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
  60 #define MAX_OPTINSN_SIZE                                \
  61         (((unsigned long)&optprobe_template_end -       \
  62           (unsigned long)&optprobe_template_entry) +    \
  63          MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
  64
  65 extern const int kretprobe_blacklist_size;
  66
  67 void arch_remove_kprobe(struct kprobe *p);
  68 asmlinkage void kretprobe_trampoline(void);
  69
  70 /* Architecture specific copy of original instruction*/
  71 struct arch_specific_insn {
  72         /* copy of the original instruction */
  73         kprobe_opcode_t *insn;
  74         /*
  75          * boostable = -1: This instruction type is not boostable.
  76          * boostable = 0: This instruction type is boostable.
  77          * boostable = 1: This instruction has been boosted: we have
  78          * added a relative jump after the instruction copy in insn,
  79          * so no single-step and fixup are needed (unless there's
  80          * a post_handler or break_handler).
  81          */
  82         int boostable;
  83         bool if_modifier;
  84 };
  85
  86 struct arch_optimized_insn {
  87         /* copy of the original instructions */
  88         kprobe_opcode_t copied_insn[RELATIVE_ADDR_SIZE];
  89         /* detour code buffer */
  90         kprobe_opcode_t *insn;
  91         /* the size of instructions copied to detour code buffer */
  92         size_t size;
  93 };
  94
  95 /* Return true (!0) if optinsn is prepared for optimization. */
  96 static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
  97 {
  98         return optinsn->size;
  99 }
 100
 101 struct prev_kprobe {
 102         struct kprobe *kp;
 103         unsigned long status;
 104         unsigned long old_flags;
 105         unsigned long saved_flags;
 106 };
 107
 108 /* per-cpu kprobe control block */
 109 struct kprobe_ctlblk {
 110         unsigned long kprobe_status;
 111         unsigned long kprobe_old_flags;
 112         unsigned long kprobe_saved_flags;
 113         unsigned long *jprobe_saved_sp;
 114         struct pt_regs jprobe_saved_regs;
 115         kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
 116         struct prev_kprobe prev_kprobe;
 117 };
 118
 119 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
 120 extern int kprobe_exceptions_notify(struct notifier_block *self,
 121                                     unsigned long val, void *data);
 122 extern int kprobe_int3_handler(struct pt_regs *regs);
 123 extern int kprobe_debug_handler(struct pt_regs *regs);
 124
 125 #endif /* CONFIG_KPROBES */
 126 #endif /* _ASM_X86_KPROBES_H */