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