arch/powerpc/include/asm/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 #include <asm/probes.h>
  33
  34 #define  __ARCH_WANT_KPROBES_INSN_SLOT
  35
  36 struct pt_regs;
  37 struct kprobe;
  38
  39 typedef ppc_opcode_t kprobe_opcode_t;
  40 #define MAX_INSN_SIZE 1
  41
  42 #ifdef CONFIG_PPC64
  43 /*
  44  * 64bit powerpc uses function descriptors.
  45  * Handle cases where:
  46  *              - User passes a <.symbol> or <module:.symbol>
  47  *              - User passes a <symbol> or <module:symbol>
  48  *              - User passes a non-existent symbol, kallsyms_lookup_name
  49  *                returns 0. Don't deref the NULL pointer in that case
  50  */
  51 #define kprobe_lookup_name(name, addr)                                  \
  52 {                                                                       \
  53         addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);           \
  54         if (addr) {                                                     \
  55                 char *colon;                                            \
  56                 if ((colon = strchr(name, ':')) != NULL) {              \
  57                         colon++;                                        \
  58                         if (*colon != '\0' && *colon != '.')            \
  59                                 addr = *(kprobe_opcode_t **)addr;       \
  60                 } else if (name[0] != '.')                              \
  61                         addr = *(kprobe_opcode_t **)addr;               \
  62         } else {                                                        \
  63                 char dot_name[KSYM_NAME_LEN];                           \
  64                 dot_name[0] = '.';                                      \
  65                 dot_name[1] = '\0';                                     \
  66                 strncat(dot_name, name, KSYM_NAME_LEN - 2);             \
  67                 addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); \
  68         }                                                               \
  69 }
  70 #endif
  71
  72 #define flush_insn_slot(p)      do { } while (0)
  73 #define kretprobe_blacklist_size 0
  74
  75 void kretprobe_trampoline(void);
  76 extern void arch_remove_kprobe(struct kprobe *p);
  77
  78 /* Architecture specific copy of original instruction */
  79 struct arch_specific_insn {
  80         /* copy of original instruction */
  81         kprobe_opcode_t *insn;
  82         /*
  83          * Set in kprobes code, initially to 0. If the instruction can be
  84          * eumulated, this is set to 1, if not, to -1.
  85          */
  86         int boostable;
  87 };
  88
  89 struct prev_kprobe {
  90         struct kprobe *kp;
  91         unsigned long status;
  92         unsigned long saved_msr;
  93 };
  94
  95 /* per-cpu kprobe control block */
  96 struct kprobe_ctlblk {
  97         unsigned long kprobe_status;
  98         unsigned long kprobe_saved_msr;
  99         struct pt_regs jprobe_saved_regs;
 100         struct prev_kprobe prev_kprobe;
 101 };
 102
 103 extern int kprobe_exceptions_notify(struct notifier_block *self,
 104                                         unsigned long val, void *data);
 105 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
 106 #endif /* __KERNEL__ */
 107 #endif  /* _ASM_POWERPC_KPROBES_H */