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 #include <linux/types.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/percpu.h>
  27 #include <asm/insn.h>
  28
  29 #define  __ARCH_WANT_KPROBES_INSN_SLOT
  30 #define  ARCH_SUPPORTS_KPROBES_ON_FTRACE
  31
  32 struct pt_regs;
  33 struct kprobe;
  34
  35 typedef u8 kprobe_opcode_t;
  36 #define BREAKPOINT_INSTRUCTION  0xcc
  37 #define RELATIVEJUMP_OPCODE 0xe9
  38 #define RELATIVEJUMP_SIZE 5
  39 #define RELATIVECALL_OPCODE 0xe8
  40 #define RELATIVE_ADDR_SIZE 4
  41 #define MAX_STACK_SIZE 64
  42 #define MIN_STACK_SIZE(ADDR)                                           \
  43         (((MAX_STACK_SIZE) < (((unsigned long)current_thread_info()) + \
  44                               THREAD_SIZE - (unsigned long)(ADDR)))    \
  45          ? (MAX_STACK_SIZE)                                            \
  46          : (((unsigned long)current_thread_info()) +                   \
  47             THREAD_SIZE - (unsigned long)(ADDR)))
  48
  49 #define flush_insn_slot(p)      do { } while (0)
  50
  51 /* optinsn template addresses */
  52 extern kprobe_opcode_t optprobe_template_entry;
  53 extern kprobe_opcode_t optprobe_template_val;
  54 extern kprobe_opcode_t optprobe_template_call;
  55 extern kprobe_opcode_t optprobe_template_end;
  56 #define MAX_OPTIMIZED_LENGTH (MAX_INSN_SIZE + RELATIVE_ADDR_SIZE)
  57 #define MAX_OPTINSN_SIZE                                \
  58         (((unsigned long)&optprobe_template_end -       \
  59           (unsigned long)&optprobe_template_entry) +    \
  60          MAX_OPTIMIZED_LENGTH + RELATIVEJUMP_SIZE)
  61
  62 extern const int kretprobe_blacklist_size;
  63
  64 void arch_remove_kprobe(struct kprobe *p);
  65 void kretprobe_trampoline(void);
  66
  67 /* Architecture specific copy of original instruction*/
  68 struct arch_specific_insn {
  69         /* copy of the original instruction */
  70         kprobe_opcode_t *insn;
  71         /*
  72          * boostable = -1: This instruction type is not boostable.
  73          * boostable = 0: This instruction type is boostable.
  74          * boostable = 1: This instruction has been boosted: we have
  75          * added a relative jump after the instruction copy in insn,
  76          * so no single-step and fixup are needed (unless there's
  77          * a post_handler or break_handler).
  78          */
  79         int boostable;
  80         bool if_modifier;
  81 };
  82
  83 struct arch_optimized_insn {
  84         /* copy of the original instructions */
  85         kprobe_opcode_t copied_insn[RELATIVE_ADDR_SIZE];
  86         /* detour code buffer */
  87         kprobe_opcode_t *insn;
  88         /* the size of instructions copied to detour code buffer */
  89         size_t size;
  90 };
  91
  92 /* Return true (!0) if optinsn is prepared for optimization. */
  93 static inline int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
  94 {
  95         return optinsn->size;
  96 }
  97
  98 struct prev_kprobe {
  99         struct kprobe *kp;
 100         unsigned long status;
 101         unsigned long old_flags;
 102         unsigned long saved_flags;
 103 };
 104
 105 /* per-cpu kprobe control block */
 106 struct kprobe_ctlblk {
 107         unsigned long kprobe_status;
 108         unsigned long kprobe_old_flags;
 109         unsigned long kprobe_saved_flags;
 110         unsigned long *jprobe_saved_sp;
 111         struct pt_regs jprobe_saved_regs;
 112         kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
 113         struct prev_kprobe prev_kprobe;
 114 };
 115
 116 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
 117 extern int kprobe_exceptions_notify(struct notifier_block *self,
 118                                     unsigned long val, void *data);
 119 #endif /* _ASM_X86_KPROBES_H */