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
  33#define  __ARCH_WANT_KPROBES_INSN_SLOT
  34
  35struct pt_regs;
  36struct kprobe;
  37
  38typedef 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#ifdef CONFIG_PPC64
  48/*
  49 * 64bit powerpc uses function descriptors.
  50 * Handle cases where:
  51 *              - User passes a <.symbol> or <module:.symbol>
  52 *              - User passes a <symbol> or <module:symbol>
  53 *              - User passes a non-existant symbol, kallsyms_lookup_name
  54 *                returns 0. Don't deref the NULL pointer in that case
  55 */
  56#define kprobe_lookup_name(name, addr)                                  \
  57{                                                                       \
  58        addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);           \
  59        if (addr) {                                                     \
  60                char *colon;                                            \
  61                if ((colon = strchr(name, ':')) != NULL) {              \
  62                        colon++;                                        \
  63                        if (*colon != '\0' && *colon != '.')            \
  64                                addr = *(kprobe_opcode_t **)addr;       \
  65                } else if (name[0] != '.')                              \
  66                        addr = *(kprobe_opcode_t **)addr;               \
  67        } else {                                                        \
  68                char dot_name[KSYM_NAME_LEN];                           \
  69                dot_name[0] = '.';                                      \
  70                dot_name[1] = '\0';                                     \
  71                strncat(dot_name, name, KSYM_NAME_LEN - 2);             \
  72                addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); \
  73        }                                                               \
  74}
  75
  76#define is_trap(instr)  (IS_TW(instr) || IS_TD(instr) || \
  77                        IS_TWI(instr) || IS_TDI(instr))
  78#else
  79/* Use stock kprobe_lookup_name since ppc32 doesn't use function descriptors */
  80#define is_trap(instr)  (IS_TW(instr) || IS_TWI(instr))
  81#endif
  82
  83#define flush_insn_slot(p)      do { } while (0)
  84#define kretprobe_blacklist_size 0
  85
  86void kretprobe_trampoline(void);
  87extern void arch_remove_kprobe(struct kprobe *p);
  88
  89/* Architecture specific copy of original instruction */
  90struct arch_specific_insn {
  91        /* copy of original instruction */
  92        kprobe_opcode_t *insn;
  93        /*
  94         * Set in kprobes code, initially to 0. If the instruction can be
  95         * eumulated, this is set to 1, if not, to -1.
  96         */
  97        int boostable;
  98};
  99
 100struct prev_kprobe {
 101        struct kprobe *kp;
 102        unsigned long status;
 103        unsigned long saved_msr;
 104};
 105
 106/* per-cpu kprobe control block */
 107struct kprobe_ctlblk {
 108        unsigned long kprobe_status;
 109        unsigned long kprobe_saved_msr;
 110        struct pt_regs jprobe_saved_regs;
 111        struct prev_kprobe prev_kprobe;
 112};
 113
 114extern int kprobe_exceptions_notify(struct notifier_block *self,
 115                                        unsigned long val, void *data);
 116extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
 117#endif /* __KERNEL__ */
 118#endif  /* _ASM_POWERPC_KPROBES_H */
 119