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