include/asm-i386/kprobes.h

   1 #ifndef _ASM_KPROBES_H
   2 #define _ASM_KPROBES_H
   3 /*
   4  *  Kernel Probes (KProbes)
   5  *  include/asm-i386/kprobes.h
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  *
  21  * Copyright (C) IBM Corporation, 2002, 2004
  22  *
  23  * 2002-Oct     Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
  24  *              Probes initial implementation ( includes suggestions from
  25  *              Rusty Russell).
  26  */
  27 #include <linux/types.h>
  28 #include <linux/ptrace.h>
  29
  30 struct pt_regs;
  31
  32 typedef u8 kprobe_opcode_t;
  33 #define BREAKPOINT_INSTRUCTION  0xcc
  34 #define MAX_INSN_SIZE 16
  35 #define MAX_STACK_SIZE 64
  36 #define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \
  37         (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \
  38         ? (MAX_STACK_SIZE) \
  39         : (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
  40
  41 #define JPROBE_ENTRY(pentry)    (kprobe_opcode_t *)pentry
  42 #define ARCH_SUPPORTS_KRETPROBES
  43
  44 void kretprobe_trampoline(void);
  45
  46 /* Architecture specific copy of original instruction*/
  47 struct arch_specific_insn {
  48         /* copy of the original instruction */
  49         kprobe_opcode_t insn[MAX_INSN_SIZE];
  50 };
  51
  52 struct prev_kprobe {
  53         struct kprobe *kp;
  54         unsigned long status;
  55         unsigned long old_eflags;
  56         unsigned long saved_eflags;
  57 };
  58
  59 /* per-cpu kprobe control block */
  60 struct kprobe_ctlblk {
  61         unsigned long kprobe_status;
  62         unsigned long kprobe_old_eflags;
  63         unsigned long kprobe_saved_eflags;
  64         long *jprobe_saved_esp;
  65         struct pt_regs jprobe_saved_regs;
  66         kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
  67         struct prev_kprobe prev_kprobe;
  68 };
  69
  70 /* trap3/1 are intr gates for kprobes.  So, restore the status of IF,
  71  * if necessary, before executing the original int3/1 (trap) handler.
  72  */
  73 static inline void restore_interrupts(struct pt_regs *regs)
  74 {
  75         if (regs->eflags & IF_MASK)
  76                 local_irq_enable();
  77 }
  78
  79 #ifdef CONFIG_KPROBES
  80 extern int kprobe_exceptions_notify(struct notifier_block *self,
  81                                     unsigned long val, void *data);
  82 #else                           /* !CONFIG_KPROBES */
  83 static inline int kprobe_exceptions_notify(struct notifier_block *self,
  84                                            unsigned long val, void *data)
  85 {
  86         return 0;
  87 }
  88 #endif
  89 #endif                          /* _ASM_KPROBES_H */