LXR linux/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#include <asm/code-patching.h>
  34
  35#define  __ARCH_WANT_KPROBES_INSN_SLOT
  36
  37struct pt_regs;
  38struct kprobe;
  39
  40typedef ppc_opcode_t kprobe_opcode_t;
  41#define MAX_INSN_SIZE 1
  42
  43#ifdef CONFIG_PPC64
  44#if defined(_CALL_ELF) && _CALL_ELF == 2
  45/* PPC64 ABIv2 needs local entry point */
  46#define kprobe_lookup_name(name, addr)                                  \
  47{                                                                       \
  48        addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);           \
  49        if (addr)                                                       \
  50                addr = (kprobe_opcode_t *)ppc_function_entry(addr);     \
  51}
  52#else
  53/*
  54 * 64bit powerpc ABIv1 uses function descriptors:
  55 * - Check for the dot variant of the symbol first.
  56 * - If that fails, try looking up the symbol provided.
  57 *
  58 * This ensures we always get to the actual symbol and not the descriptor.
  59 * Also handle <module:symbol> format.
  60 */
  61#define kprobe_lookup_name(name, addr)                                  \
  62{                                                                       \
  63        char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN];             \
  64        char *modsym;                                                   \
  65        bool dot_appended = false;                                      \
  66        if ((modsym = strchr(name, ':')) != NULL) {                     \
  67                modsym++;                                               \
  68                if (*modsym != '\0' && *modsym != '.') {                \
  69                        /* Convert to <module:.symbol> */               \
  70                        strncpy(dot_name, name, modsym - name);         \
  71                        dot_name[modsym - name] = '.';                  \
  72                        dot_name[modsym - name + 1] = '\0';             \
  73                        strncat(dot_name, modsym,                       \
  74                                sizeof(dot_name) - (modsym - name) - 2);\
  75                        dot_appended = true;                            \
  76                } else {                                                \
  77                        dot_name[0] = '\0';                             \
  78                        strncat(dot_name, name, sizeof(dot_name) - 1);  \
  79                }                                                       \
  80        } else if (name[0] != '.') {                                    \
  81                dot_name[0] = '.';                                      \
  82                dot_name[1] = '\0';                                     \
  83                strncat(dot_name, name, KSYM_NAME_LEN - 2);             \
  84                dot_appended = true;                                    \
  85        } else {                                                        \
  86                dot_name[0] = '\0';                                     \
  87                strncat(dot_name, name, KSYM_NAME_LEN - 1);             \
  88        }                                                               \
  89        addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name);       \
  90        if (!addr && dot_appended) {                                    \
  91                /* Let's try the original non-dot symbol lookup */      \
  92                addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);   \
  93        }                                                               \
  94}
  95#endif /* defined(_CALL_ELF) && _CALL_ELF == 2 */
  96#endif /* CONFIG_PPC64 */
  97
  98#define flush_insn_slot(p)      do { } while (0)
  99#define kretprobe_blacklist_size 0
 100
 101void kretprobe_trampoline(void);
 102extern void arch_remove_kprobe(struct kprobe *p);
 103
 104/* Architecture specific copy of original instruction */
 105struct arch_specific_insn {
 106        /* copy of original instruction */
 107        kprobe_opcode_t *insn;
 108        /*
 109         * Set in kprobes code, initially to 0. If the instruction can be
 110         * eumulated, this is set to 1, if not, to -1.
 111         */
 112        int boostable;
 113};
 114
 115struct prev_kprobe {
 116        struct kprobe *kp;
 117        unsigned long status;
 118        unsigned long saved_msr;
 119};
 120
 121/* per-cpu kprobe control block */
 122struct kprobe_ctlblk {
 123        unsigned long kprobe_status;
 124        unsigned long kprobe_saved_msr;
 125        struct pt_regs jprobe_saved_regs;
 126        struct prev_kprobe prev_kprobe;
 127};
 128
 129extern int kprobe_exceptions_notify(struct notifier_block *self,
 130                                        unsigned long val, void *data);
 131extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
 132#endif /* __KERNEL__ */
 133#endif  /* _ASM_POWERPC_KPROBES_H */
 134