include/asm-powerpc/kprobes.h

   1 #ifndef _ASM_POWERPC_KPROBES_H
   2 #define _ASM_POWERPC_KPROBES_H
   3 #ifdef __KERNEL__
   4 /*
   5  *  Kernel Probes (KProbes)
   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  * 2004-Nov     Modified for PPC64 by Ananth N Mavinakayanahalli
  27  *              <ananth@in.ibm.com>
  28  */
  29 #include <linux/types.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/percpu.h>
  32
  33 #define  __ARCH_WANT_KPROBES_INSN_SLOT
  34
  35 struct pt_regs;
  36 struct kprobe;
  37
  38 typedef unsigned int kprobe_opcode_t;
  39 #define BREAKPOINT_INSTRUCTION  0x7fe00008      /* trap */
  40 #define MAX_INSN_SIZE 1
  41
  42 #define IS_TW(instr)            (((instr) & 0xfc0007fe) == 0x7c000008)
  43 #define IS_TD(instr)            (((instr) & 0xfc0007fe) == 0x7c000088)
  44 #define IS_TDI(instr)           (((instr) & 0xfc000000) == 0x08000000)
  45 #define IS_TWI(instr)           (((instr) & 0xfc000000) == 0x0c000000)
  46
  47 /*
  48  * 64bit powerpc uses function descriptors.
  49  * Handle cases where:
  50  *              - User passes a <.symbol> or <module:.symbol>
  51  *              - User passes a <symbol> or <module:symbol>
  52  *              - User passes a non-existant symbol, kallsyms_lookup_name
  53  *                returns 0. Don't deref the NULL pointer in that case
  54  */
  55 #define kprobe_lookup_name(name, addr)                                  \
  56 {                                                                       \
  57         addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);           \
  58         if (addr) {                                                     \
  59                 char *colon;                                            \
  60                 if ((colon = strchr(name, ':')) != NULL) {              \
  61                         colon++;                                        \
  62                         if (*colon != '\0' && *colon != '.')            \
  63                                 addr = *(kprobe_opcode_t **)addr;       \
  64                 } else if (name[0] != '.')                              \
  65                         addr = *(kprobe_opcode_t **)addr;               \
  66         }                                                               \
  67 }
  68
  69 #define JPROBE_ENTRY(pentry)    (kprobe_opcode_t *)((func_descr_t *)pentry)
  70
  71 #define is_trap(instr)  (IS_TW(instr) || IS_TD(instr) || \
  72                         IS_TWI(instr) || IS_TDI(instr))
  73
  74 #define ARCH_SUPPORTS_KRETPROBES
  75 #define  ARCH_INACTIVE_KPROBE_COUNT 1
  76 #define flush_insn_slot(p)      do { } while (0)
  77
  78 void kretprobe_trampoline(void);
  79 extern void arch_remove_kprobe(struct kprobe *p);
  80
  81 /* Architecture specific copy of original instruction */
  82 struct arch_specific_insn {
  83         /* copy of original instruction */
  84         kprobe_opcode_t *insn;
  85 };
  86
  87 struct prev_kprobe {
  88         struct kprobe *kp;
  89         unsigned long status;
  90         unsigned long saved_msr;
  91 };
  92
  93 /* per-cpu kprobe control block */
  94 struct kprobe_ctlblk {
  95         unsigned long kprobe_status;
  96         unsigned long kprobe_saved_msr;
  97         struct pt_regs jprobe_saved_regs;
  98         struct prev_kprobe prev_kprobe;
  99 };
 100
 101 extern int kprobe_exceptions_notify(struct notifier_block *self,
 102                                         unsigned long val, void *data);
 103 #endif /* __KERNEL__ */
 104 #endif  /* _ASM_POWERPC_KPROBES_H */