kernel/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
  37 struct pt_regs;
  38 struct kprobe;
  39
  40 typedef 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
 101 void kretprobe_trampoline(void);
 102 extern void arch_remove_kprobe(struct kprobe *p);
 103
 104 /* Architecture specific copy of original instruction */
 105 struct 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
 115 struct prev_kprobe {
 116         struct kprobe *kp;
 117         unsigned long status;
 118         unsigned long saved_msr;
 119 };
 120
 121 /* per-cpu kprobe control block */
 122 struct 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
 129 extern int kprobe_exceptions_notify(struct notifier_block *self,
 130                                         unsigned long val, void *data);
 131 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
 132 #endif /* __KERNEL__ */
 133 #endif  /* _ASM_POWERPC_KPROBES_H */